WO2018021117A1 - Semiconductor element production method and solar cell production method - Google Patents

Abstract

The semiconductor element production method according to one embodiment includes a film layer formation step and a diffusion step. In the film layer formation step, an A film and a B film are formed on a semiconductor substrate. The A film is an impurity diffusion composition film that is formed using a composition A that contains an impurity diffusion component. The B film is an air diffusion suppression layer that suppresses the air diffusion of the impurity diffusion component from at least the A film and that is formed using a composition B that contains a polysiloxane. In the diffusion step, the semiconductor substrate on which the A film and the B film are formed is heat treated, and the impurity diffusion component is thereby diffused into the semiconductor substrate. This semiconductor element production method is for use in a solar cell production method.

Description

Method for manufacturing semiconductor device and method for manufacturing solar cell

The present invention relates to a method for manufacturing a semiconductor element and a method for manufacturing a solar cell.

Currently, in the manufacture of a semiconductor element such as a solar cell, when an n-type or p-type impurity diffusion layer is formed in a semiconductor substrate, an impurity diffusion source is formed on the semiconductor substrate, and thermal diffusion is performed in the semiconductor substrate. A method of diffusing impurity diffusion components is employed. The impurity diffusion source is formed by a CVD method or a solution coating method of a liquid impurity diffusion composition.

For example, when using a liquid impurity diffusion composition, a thermal oxide film is first formed on the surface of the semiconductor substrate, and then a resist having a predetermined pattern is laminated on the thermal oxide film by photolithography. Then, using the resist as a mask, the portion of the thermal oxide film not masked with the resist is etched with acid or alkali, and then the resist is removed to form a mask with the thermal oxide film. Subsequently, an n-type or p-type impurity diffusion composition is applied, and the impurity diffusion composition is adhered to the portion where the mask is opened. Thereafter, the impurity diffusion component in the composition is thermally diffused into the semiconductor substrate at 600 ° C. to 1250 ° C. to form an n-type or p-type impurity diffusion layer.

With regard to the manufacture of such semiconductor elements such as solar cells, in recent years, the impurity diffusion layer is patterned at low cost by simply patterning the impurity diffusion source by a printing method or the like without using conventional photolithography technology. It has been studied to manufacture semiconductor devices such as solar cells (see, for example, Patent Document 1).

In any of the above-described methods, for example, when an n-type impurity diffusion layer is formed, an n-type impurity diffusion component (a mask layer is formed in a region other than the n-type impurity diffusion source on the semiconductor substrate ( Hereinafter, it is necessary to take measures so that “n-type impurities” are appropriately abbreviated outside the region to be originally diffused. In that case, after diffusing the n-type impurity in the semiconductor substrate, the mask layer is removed, and if necessary, a mask layer is formed again in the region where the n-type impurity is diffused, and regions other than the mask layer are formed. Then, a p-type impurity diffusion component (hereinafter abbreviated as “p-type impurity” as appropriate) is diffused.

In order to avoid such a complicated process, a technique is also known in which after the n-type impurity is diffused, the fired film of the n-type impurity diffusion source is used as it is as a mask layer to diffuse the p-type impurity (for example, Patent Document 2).

JP 2003-168810 A International Publication No. 2015/002132

However, even in the case of the method described in Patent Document 2, n-type impurities and p-type impurities are inherently diffused unless a mask layer is formed on a portion of the semiconductor substrate where the impurity diffusion composition is not formed. There was a problem of mixing outside the area to be.

As described above, when each of the n-type and p-type impurity diffusion layers is formed in the semiconductor substrate, a patterned mask layer is formed in order to diffuse the target impurity diffusion component into a desired region in the semiconductor substrate. Therefore, there is a problem that the process becomes longer and the manufacturing cost and tact time (process work time) increase.

The present invention has been made in view of the above-described problems, and is a semiconductor element capable of diffusing a target impurity diffusion component (n-type impurity or p-type impurity) into a desired region in a semiconductor substrate with a small number of steps. An object of the present invention is to provide a method for producing a solar cell and a method for producing a solar cell.

The present inventors have found that the above problems can be solved by suppressing the in-air diffusion of impurity diffusion components from an impurity diffusion source formed on a semiconductor substrate, and have reached the present invention.

That is, in order to solve the above-described problems and achieve the object, a method for manufacturing a semiconductor device according to the present invention includes an impurity diffusion composition film using a composition A containing an impurity diffusion component on a semiconductor substrate. And a B layer, which is an air diffusion suppression layer that suppresses at least air diffusion of the impurity diffusion component from the A film. A film layer forming step; and a diffusion step of heat-treating the semiconductor substrate on which the A film and the B layer are formed to diffuse the impurity diffusion component in the semiconductor substrate.

Further, in the method of manufacturing a semiconductor device according to the present invention, in the above invention, the film layer forming step includes forming the A film by applying the composition A to a predetermined surface of the semiconductor substrate. And a B layer forming step of forming the B layer by applying the composition B on the A film.

Moreover, in the method for manufacturing a semiconductor device according to the present invention, in the above invention, the film layer forming step includes the step of forming the film A on the film A and the film A formed using the composition A in advance. The method includes a step of laminating and forming a laminated body with the B layer formed on a predetermined surface of the semiconductor substrate.

In addition, the method for manufacturing a semiconductor element according to the present invention is characterized in that, in the above invention, the thickness of the B layer after drying is 200 [nm] or more and 2000 [nm] or less.

Further, the semiconductor element manufacturing method according to the present invention is characterized in that, in the above invention, the composition A contains a binder resin.

In addition, the method for manufacturing a semiconductor device according to the present invention is characterized in that, in the above invention, the composition B contains polysiloxane represented by the following general formula (1).

（一般式（１）中、Ｒ¹は炭素数６～１５のアリール基を表し、複数のＲ¹はそれぞれ同じでも異なっていてもよい。Ｒ³は炭素数１～６のアルキル基または炭素数２～１０のアルケニル基を表し、複数のＲ³はそれぞれ同じでも異なっていてもよい。Ｒ²およびＲ⁴は水酸基、炭素数１～６のアルコキシ基、炭素数１～６のアシルオキシ基のいずれかを表し、複数のＲ²およびＲ⁴はそれぞれ同じでも異なっていてもよい。ただし、Ｒ²およびＲ⁴のうちいずれか一方は必ず水酸基である。ｎおよびｍは各括弧内の成分の構成比率（％）を示し、ｎ＋ｍ＝１００であり、ｎ：ｍ＝９０：１０～４０：６０である。Ｘは水酸基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数１～６のアシルオキシ基、炭素数２～１０のアルケニル基、炭素数６～１５のアリール基、炭素数３～１２のヘテロアリール基のいずれかである。Ｙは水素原子、炭素数１～６のアルキル基、炭素数１～７のアシル基のいずれかである。）

(In the general formula (1), R ¹ represents an aryl group having 6 to 15 carbon atoms, and a plurality of R ¹ may be the same or different. R ³ represents an alkyl group having 1 to 6 carbon atoms or a carbon number. an alkenyl group of 2 to 10, any good .R ² and R ⁴ be with or different multiple R ³ identical each a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 6 carbon atoms A plurality of R ² and R ⁴ may be the same or different from each other, provided that either one of R ² and R ⁴ is necessarily a hydroxyl group, and n and m are constituents of components in parentheses. N + m = 100, n: m = 90: 10 to 40:60, where X is a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, carbon An acyloxy group having 1 to 6 carbon atoms and an alkeni having 2 to 10 carbon atoms Any one of a group, an aryl group having 6 to 15 carbon atoms, and a heteroaryl group having 3 to 12 carbon atoms, Y is any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and an acyl group having 1 to 7 carbon atoms. )

The semiconductor device manufacturing method according to the present invention is characterized in that, in the above invention, the composition A and the composition B are incompatible compositions with each other.

Moreover, in the method for manufacturing a semiconductor element according to the present invention, in the above invention, the composition A contains a binder resin, and the decomposition temperature of the binder resin is higher than the curing temperature of the polysiloxane contained in the composition B. It is characterized by being low.

The method for manufacturing a semiconductor element according to the present invention is characterized in that, in the above invention, the film layer forming step forms the A film and the B layer continuously without going through a drying step by heat treatment. To do.

Also, the method for manufacturing a semiconductor device according to the present invention is characterized in that, in the above invention, the A film and the B layer are formed by a spin coating method.

In the method of manufacturing a semiconductor element according to the present invention, the A film formation step and the B layer formation step are continuously performed without stopping rotation in the spin coating method. And

Further, in the method of manufacturing a semiconductor element according to the present invention, in the above invention, the composition A contains a water-soluble binder resin, the composition B contains a solvent, and the water-soluble binder resin with respect to the solvent The solubility is 0.01 [g / mL] or less at 25 ° C.

The semiconductor device manufacturing method according to the present invention is characterized in that, in the above invention, the composition A contains a boron compound, polyvinyl alcohol and water.

In the semiconductor device manufacturing method according to the present invention, in the above invention, an impurity diffusion composition film having a conductivity type different from that of the A film is formed on a surface of the semiconductor substrate opposite to the A film. A step of forming a film, wherein the diffusion step includes heat-treating the semiconductor substrate on which the impurity diffusion composition film, the A film, and the B layer are formed, to diffuse impurities from the impurity diffusion composition film. A component is diffused into the semiconductor substrate, and an impurity diffusion component from the A film is diffused into the semiconductor substrate, and an impurity diffusion layer from the impurity diffusion composition film and an impurity diffusion layer from the A film are formed. At the same time, it is formed on the semiconductor substrate.

Further, a method for manufacturing a solar cell according to the present invention includes the method for manufacturing a semiconductor element according to any one of the above inventions.

According to the present invention, the number of steps required for the thermal diffusion of the impurity diffusion component into the semiconductor substrate can be reduced, and contamination of the semiconductor substrate due to the atmospheric diffusion of the impurity diffusion component during the thermal diffusion of the impurity diffusion component (semiconductor substrate) Among them, the target impurity diffusion component can be efficiently diffused with high purity in a desired region of the semiconductor substrate while preventing the impurity diffusion component from being mixed or diffused in an undesired region. As a result, it is possible to achieve both shortening the process of manufacturing the semiconductor element (and thus manufacturing the solar cell) and increasing the efficiency.

FIG. 1 is a diagram showing an example of a method for manufacturing a semiconductor element according to Embodiment 1 of the present invention. FIG. 2A is a diagram illustrating an example of a method of manufacturing a semiconductor element according to Embodiment 2 of the present invention. FIG. 2B is a diagram illustrating an example of a solar cell manufacturing method according to Embodiment 2 of the present invention. FIG. 3A is a diagram illustrating an example of a method of manufacturing a semiconductor element according to Embodiment 3 of the present invention. FIG. 3B is a diagram illustrating an example of a solar cell manufacturing method according to Embodiment 3 of the present invention. FIG. 4 is a diagram for explaining each evaluation of peelability, diffusibility, diffusion uniformity, and barrier property in the examples of the present invention. FIG. 5 is a diagram illustrating air diffusivity evaluation in the example of the present invention.

Hereinafter, preferred embodiments of a method for manufacturing a semiconductor element and a method for manufacturing a solar cell according to the present invention will be described in detail with reference to the drawings as necessary. Note that the present invention is not limited to these embodiments.

A method for manufacturing a semiconductor device and a method for manufacturing a solar cell according to the present invention include a film layer forming step of forming an A film and a B layer on a semiconductor substrate, and a semiconductor substrate in which these A film and B layer are formed. And a diffusion step of diffusing (thermally diffusing) the impurity diffusion component by heat treatment. In these manufacturing methods, the A film is an impurity diffusion composition film using the composition A. The composition A is an example of an impurity diffusion composition containing a target impurity diffusion component to be diffused into the semiconductor substrate. On the other hand, the B layer is an example of an air diffusion suppression layer that uses the composition B and suppresses at least air diffusion of impurity diffusion components from the A film. The composition B is an example of a composition containing polysiloxane suitable for forming an air diffusion suppression layer. Hereinafter, each component contained in each of these compositions A and B will be described in detail.

(Composition A)
The composition A contains an impurity diffusion component such as an n-type impurity or a p-type impurity, and a solvent. In addition to these, the composition A may contain a binder resin, or may contain additives such as a thickener and a surfactant.

(Impurity diffusion component)
The impurity diffusion component is a component for forming an n-type or p-type impurity diffusion layer in the semiconductor substrate. The n-type impurity diffusion component is preferably a compound containing a Group 15 element. As the group 15 element, phosphorus, arsenic, antimony and bismuth are preferable, and phosphorus is particularly preferable. The p-type impurity diffusion component is preferably a compound containing a Group 13 element. As the group 13 element, boron, aluminum and gallium are preferable, and boron is particularly preferable.

Examples of phosphorus compounds include phosphate esters and phosphites. Examples of phosphate esters include diphosphorus pentoxide, phosphoric acid, polyphosphoric acid, methyl phosphate, dimethyl phosphate, trimethyl phosphate, ethyl phosphate, diethyl phosphate, triethyl phosphate, propyl phosphate, and dipropyl phosphate. , Tripropyl phosphate, butyl phosphate, dibutyl phosphate, tributyl phosphate, phenyl phosphate, diphenyl phosphate, triphenyl phosphate, and the like. Examples of the phosphite ester include methyl phosphite, dimethyl phosphite, trimethyl phosphite, ethyl phosphite, diethyl phosphite, triethyl phosphite, propyl phosphite, dipropyl phosphite, Examples include tripropyl phosphate, butyl phosphite, dibutyl phosphite, tributyl phosphite, phenyl phosphite, diphenyl phosphite, triphenyl phosphite and the like. Of these, phosphoric acid, diphosphorus pentoxide or polyphosphoric acid is preferable from the viewpoint of doping.

Examples of the boron compound include boric acid, diboron trioxide, methyl boronic acid, phenyl boronic acid, trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, trioctyl borate, triphenyl borate and the like. It is done. Of these, boric acid and diboron trioxide are preferable from the viewpoint of doping.

(Binder resin)
As the binder resin in the composition A, it is particularly preferable to use a water-soluble binder resin. Here, the water-soluble binder resin refers to a resin having a solubility of 10% by weight or more with respect to water at 25 ° C.

Specifically, examples of the binder resin in the composition A include the following. For example, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, polyacrylamide resin, polyvinyl pyrrolidone resin, polyethylene oxide resin, acrylamide alkyl sulfone resin, cellulose derivative, gelatin, gelatin derivative, starch, starch derivative, sodium alginate compound, xanthan, guar gum, guar gum Derivatives, scleroglucan, scleroglucan derivatives, tragacanth, tragacanth derivatives, dextrin, dextrin derivatives, water-soluble (meth) acrylate resins, water-soluble polybutadiene resins, water-soluble styrene resins, butyral resins, copolymers thereof Is mentioned. However, the binder resin in the composition A is not limited to these. The above “(meth) acrylic acid” means “acrylic acid or methacrylic acid”.

In composition A, the binder resin can be used alone or in combination of two or more. In particular, when the impurity diffusion component contained in the composition A is a boron compound, the binder resin has a 1,2-diol structure or 1 from the viewpoint of the formability of the complex with the boron compound and the stability of the formed complex. 1,3-diol structure is preferable, and polyvinyl alcohol is particularly preferable.

Further, the polymerization degree of the binder resin in the composition A is not particularly limited, but the preferable polymerization degree range is 1000 or less, and particularly preferably 800 or less. As a result, excellent solubility of a hydroxyl group-containing polymer such as polyvinyl alcohol in an organic solvent is exhibited. On the other hand, the lower limit of the degree of polymerization is not particularly limited, but is preferably 100 or more from the viewpoint of easy handling of the binder resin. In the present invention, the degree of polymerization of the binder resin is determined as the number average degree of polymerization in terms of polystyrene in GPC (gel permeation chromatography) analysis.

(solvent)
The solvent in the composition A is not particularly limited, but a solvent capable of satisfactorily dissolving or dispersing the impurity diffusion component and the binder resin contained in the composition A is preferable. Specifically, examples of such a solvent include water, alcohols, glycols, ethers, ketones, amides, acetates, aromatic or aliphatic hydrocarbons, γ-butyrolactone, N-methyl-2 -Pyrrolidone, N, N-dimethylimidazolidinone, dimethyl sulfoxide, propylene carbonate and the like.

Examples of alcohols include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, 1-methoxy-2-propanol, pentanol, 4-methyl-2-pentanol, and 3-methyl-2- Examples include butanol, 3-methyl-3-methoxy-1-butanol, 1-t-butoxy-2-propanol, diacetone alcohol, terpineol, and texanol. Examples of glycols include ethylene glycol and propylene glycol.

Examples of ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol-t-butyl ether, propylene glycol-n-butyl ether ethylene glycol Dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol-n-butyl ether, dipropylene glycol monomethyl ether, diisopropyl ether, di-n-butyl ether, diphenyl ether, diethylene glycol ethyl methyl ether Ether, diethylene glycol dimethyl ether, ethylene glycol monobutyl ether.

Examples of ketones include methyl ethyl ketone, acetyl acetone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, 2-heptanone, cyclohexanone, and cycloheptanone. Examples of amides include dimethylformamide and dimethylacetamide.

Examples of acetates include isopropyl acetate, ethyl acetate, propyl acetate, butyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether Acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, butyl diglycol acetate, 1,3-butylene glycol diacetate, ethyl diglycol acetate, di Propylene glycol methyl ether acetate, methyl lactate, ethyl lactate, butyl lactate Triacetyl glycerin. Examples of the aromatic or aliphatic hydrocarbon include toluene, xylene, hexane, cyclohexane, ethyl benzoate, naphthalene, 1,2,3,4-tetrahydronaphthalene and the like.

Further, in order to stably form the B layer on the A film, it is preferable that the A film and the B layer are not compatible with each other. That is, the composition A constituting the A film and the composition B constituting the B layer are preferably incompatible compositions. For this purpose, the A film preferably has quick drying properties, and the boiling point of the solvent in the composition A is preferably 150 ° C. or lower. In the present invention, “the composition A and the composition B are not compatible with each other” means that the composition B is applied in layers on the composition A applied in a film form on a certain surface. Of course, the composition A and the composition B are not melted at all, and even if they are melted at the interface between the composition A and the composition B, the coating film (A film) of the composition A It means that the coating layer (B layer) of the composition B has a necessary thickness and is maintained in such a manner that it can be distinguished from each other.

From the above viewpoints, the solvent in the composition A is preferably water, specific alcohols, specific ethers, specific ketones, specific acetates, specific aromatic or aliphatic hydrocarbons. .

Specifically, preferred specific alcohols include, for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, 1-methoxy-2-propanol, pentanol, 4-methyl-2-pentanol. , 3-methyl-2-butanol and the like. Preferable specific ethers include, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, diethyl ether, diisopropyl ether and the like. Preferable specific ketones include, for example, methyl ethyl ketone, acetyl acetone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, cyclopentanone and the like. Preferred specific acetates include, for example, isopropyl acetate, ethyl acetate, propyl acetate, butyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, lactic acid Examples include methyl and ethyl lactate. Preferred specific aromatic or aliphatic hydrocarbons include, for example, toluene, xylene, hexane, cyclohexane and the like.

(Additive)
Composition A may contain additives such as thickeners and surfactants as necessary. Hereinafter, this thickener will be described, and then this surfactant will be described.

Examples of thickeners include cellulose, cellulose derivatives, starch, starch derivatives, polyvinyl pyrrolidone, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, polystyrene resins, Polyester resin, synthetic rubber, natural rubber, polyacrylic acid, various acrylic resins, polyethylene glycol, polyethylene oxide, polypropylene glycol, polypropylene oxide, silicone oil, sodium alginate, xanthan gum polysaccharide, gellan gum polysaccharide, guar gum polysaccharide , Carrageenan polysaccharide, locust bean gum polysaccharide, carboxyvinyl polymer, hydrogenated castor oil system, hydrogenated castor oil system and fatty acid amidowa , A mixture of a special fatty acid, a polyethylene oxide, a mixture of a polyethylene oxide and an amide, a fatty acid polyvalent carboxylic acid, a phosphate ester surfactant, a salt of a long-chain polyaminoamide and phosphoric acid, Specially modified polyamide system is exemplified.

The content of the thickener in the composition A is preferably in the range of 0.1% by weight to 10% by weight. When the content of the thickener is within the above range, a sufficient viscosity adjusting effect of the composition A can be obtained.

The viscosity of the composition A is not particularly limited, and can be appropriately changed according to the coating method of the composition A and the film thickness of the composition A. For example, when the coating method of the composition A is a spin coating method, in order to obtain good coating properties of the composition A, the viscosity of the composition A is preferably 300 [mPa · s] or less, It is particularly preferably 100 [mPa · s] or less. In the case of a screen printing method which is one of the preferred printing forms of the composition A, the viscosity of the composition A is preferably 3,000 [mPa · s] or more. This is because it is possible to suppress the bleeding of the print pattern and obtain a good pattern. The more preferable viscosity of the composition A is 5,000 [mPa · s] or more. The upper limit of the viscosity of the composition A is not particularly limited, but is preferably 100,000 [mPa · s] or less from the viewpoint of storage stability and handleability of the composition A.

Here, when the viscosity is less than 1,000 [mPa · s], the viscosity is a value measured at a rotation speed of 5 rpm using an E-type digital viscometer based on JIS Z 8803 (1991) “Solution Viscosity—Measurement Method”. is there. When the viscosity is 1,000 [mPa · s] or more, the viscosity is a value measured at a rotation speed of 20 rpm using a B-type digital viscometer based on JIS Z 8803 (1991) “Solution Viscosity—Measurement Method”. .

As the surfactant, a fluorine-based surfactant or a silicone-based surfactant is preferably used. Specific examples of the fluorosurfactant include a fluorosurfactant composed of a compound having a fluoroalkyl or fluoroalkylene group in at least one of the terminal, main chain and side chain. Examples of such a fluorosurfactant include 1,1,2,2-tetrafluorooctyl (1,1,2,2-tetrafluoropropyl) ether, 1,1,2,2-tetrafluorooctyl. Hexyl ether, octaethylene glycol di (1,1,2,2-tetrafluorobutyl) ether, hexaethylene glycol (1,1,2,2,3,3-hexafluoropentyl) ether, octapropylene glycol di (1 , 1,2,2-tetrafluorobutyl) ether, hexapropylene glycol di (1,1,2,2,3,3-hexafluoropentyl) ether, sodium perfluorododecylsulfonate, 1,1,2,2 , 8,8,9,9,10,10-decafluorododecane, 1,1,2,2,3,3-hexafluorode N- [3- (perfluorooctanesulfonamido) propyl] -N, N'-dimethyl-N-carboxymethyleneammonium betaine, perfluoroalkylsulfonamidopropyltrimethylammonium salt, perfluoroalkyl-N-ethylsulfonylglycine Salt, bis (N-perfluorooctylsulfonyl-N-ethylaminoethyl) phosphate, monoperfluoroalkylethyl phosphate, and the like.

Moreover, as a commercial item, MegaFac F142D, F172, F173, F183, F183, F444, F475, F477 (above, manufactured by Dainippon Ink and Chemicals), Ftop EF301, 303, 352 (Manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC-430, FC-431 (manufactured by Sumitomo 3M Co., Ltd.), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (Asahi Glass Co., Ltd.), BM-1000, BM-1100 (Yusho Co., Ltd.), NBX-15, FTX-218, DFX-218 (Corporation) Fluorosurfactants such as Neos).

Commercially available silicone surfactants include, for example, SH28PA, SH7PA, SH21PA, SH30PA, ST94PA (above, manufactured by Toray Dow Corning Co., Ltd.), BYK067A, BYK310, BYK322, BYK331, BYK333, BYK355 (above, BYK Chemie Japan Co., Ltd.).

When a surfactant is added to the composition A, the content of the surfactant in the composition A is preferably 0.0001 wt% or more and 1 wt% or less.

In addition, particularly preferable as the composition A is a composition containing a boron compound, polyvinyl alcohol and water. For example, a boron compound is contained in the composition A as an impurity diffusion component. Polyvinyl alcohol is contained in the composition A as a binder resin. Water is included in Composition A as a solvent.

(Composition B)
The composition B is a composition for forming the B layer as the air diffusion suppressing layer, and contains polysiloxane and a solvent. In this polysiloxane, in the state where the B layer made of the composition B is formed on the A film, the impurity diffusion component diffuses in the air during the thermal diffusion of the impurity diffusion component from the A film into the semiconductor substrate. It is a compound having an inhibitory property. In addition to polysiloxane, the composition B may further contain a siloxane copolymer, a siloxane oligomer, silica fine particles, silica gel, and the like as a compound that suppresses air diffusion. In addition to these, the composition B may contain a binder resin or may contain additives such as a thickener and a surfactant.

(Polysiloxane)
Polysiloxane has the property of suppressing the diffusion of impurity diffusion components from the A film in the air, and this property can prevent the diffusion of impurity diffusion components into undesired portions of the semiconductor substrate. On the contrary, polysiloxane has a property of suppressing an impurity diffusion component of another conductivity type (for example, p-type relative to n-type) different from the composition A from entering the A film from the outside. Thereby, the polysiloxane can also suppress the diffusion of unwanted impurity diffusion components to the application part of the composition A (deposition part of the A film). As the polysiloxane contained in the composition B, a polysiloxane represented by the general formula (1) is particularly preferably used.

In general formula (1), R ¹ represents an aryl group having 6 to 15 carbon atoms. The plurality of R ¹ may be the same or different. R ³ represents an alkyl group having 1 to 6 carbon atoms or an alkenyl group having 2 to 10 carbon atoms. A plurality of R ³ may be the same or different. R ² and R ^{4 each} represent a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, or an acyloxy group having 1 to 6 carbon atoms. A plurality of R ² and R ⁴ may be the same or different. However, either one of R ² and R ⁴ is necessarily a hydroxyl group. n and m show the component ratio (%) of the component in each parenthesis. These n and m are n + m = 100, and preferably n: m = 90: 10 to 40:60.

The terminal group of the polysiloxane represented by the general formula (1) (for example, X and Y in the general formula (1)) is hydrogen (hydrogen atom), hydroxyl group, alkyl group having 1 to 6 carbon atoms, carbon number And any one of an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, and an alkenyl group having 2 to 10 carbon atoms.

In the “group” in the present invention, “carbon number” represents the total number of carbon atoms including a group further substituted on the group. For example, the carbon number of a butyl group substituted with a methoxy group is “5”. The polysiloxane represented by the general formula (1) may be a block copolymer or a random copolymer.

The polysiloxane preferably contains 40 mol% or more of units containing an aryl group having 6 to 15 carbon atoms in terms of Si atoms. When the composition B contains such a polysiloxane, in the B layer made of the composition B, the crosslinking density between the polysiloxane skeletons does not become too high. Therefore, even though the B layer covers the A film during the thermal diffusion of the impurity diffusing component into the semiconductor substrate, oxygen reaches the A film, so that the binder resin in the A film is thermally decomposed. Has the effect of not hindering. With this effect, no excessive residue remains on the semiconductor substrate even after thermal diffusion, and good diffusibility of impurity diffusion components from the A film into the semiconductor substrate can be obtained. For this reason, it becomes possible to achieve both good diffusibility of the impurity diffusion component and an air diffusion suppression effect of the impurity diffusion component by the B layer.

In addition, since the generation of cracks in the B layer is further suppressed by increasing the thickness of the B layer, the B layer is cracked in steps such as firing of the B layer and thermal diffusion of impurity diffusion components from the A film into the semiconductor substrate. Is difficult to enter. As a result, the B layer serves to sufficiently protect the impurity diffusion layer in the semiconductor substrate from other impurity diffusion components (masking property), and improves the stability of thermal diffusion of the impurity diffusion component into the semiconductor substrate. be able to. In order to provide the B layer with masking properties, it is preferable that the thickness of the B layer after the thermal diffusion of the impurity diffusion component is large. For this reason, even if it is a thick film, the composition B of this invention which becomes difficult to produce a crack in B layer can be utilized suitably.

In addition, even when a thermal decomposition component such as a thickener is added to the composition B, the layer B contains pores generated due to the thermal decomposition of the polysiloxane contained in the composition B. It can be filled by the reflow effect. As a result, a dense B layer with few holes can be formed. Such a dense B layer is hardly affected by the atmosphere during the thermal diffusion of the impurity diffusion component from the A film into the semiconductor substrate, and sufficiently protects the impurity diffusion layer in the semiconductor substrate from other impurity diffusion components. High masking properties can be obtained.

On the other hand, the unit containing an aryl group having 6 to 15 carbon atoms in the polysiloxane is preferably 90 mol% or less in terms of Si atoms. As a result, it becomes possible to eliminate the peeling residue of the A film after diffusing the impurity diffusion component from the semiconductor substrate. It is considered that the residue of the A film is a carbide left without the organic matter being completely decomposed and volatilized. When such a A film residue remains in the semiconductor substrate, not only does the doping of the impurity diffusion component to the semiconductor substrate be disturbed, but also the contact resistance between the electrode to be formed later and the semiconductor substrate (for example, the impurity diffusion layer) is reduced. As a result, the efficiency of the solar cell is reduced. In the polysiloxane, when the unit containing an aryl group having 6 to 15 carbon atoms exceeds 90 mol% in terms of Si atom, the composition B in the B layer is completely decomposed and volatilized before the organic components of the A film are completely decomposed and volatilized. It is considered that the film of the film A becomes too dense, and as a result, the residue of the film A is easily generated.

That is, n and m in the general formula (1) are preferably n: m = 90: 10 to 40:60. Further, in the general formula (1), when R ³ is an alkyl group, the generation of residue of the A film is suppressed by reducing the carbon number of the alkyl group to 6 or less, and reflow by the aryl group of R ¹ is performed. The effect can be fully extracted.

In order to obtain the above-described effects, the thickness of the B layer after drying is more preferably 200 [nm] or more and 2000 [nm] or less. When the film thickness after drying of B layer is 200 [nm] or more, the air diffusion suppression effect and mask property of B layer are further improved. On the other hand, when the thickness of the B layer after drying is 2000 [nm] or less, oxygen easily reaches the A film through the B layer, so that the diffusibility of the impurity diffusion component from the A film into the semiconductor substrate Will be improved. The film thickness is a value measured with Surfcom 1400D (manufactured by Tokyo Seimitsu Co., Ltd.).

Furthermore, in order to obtain good diffusibility of the impurity diffusing component as described above, it is preferable that the decomposition temperature of the binder resin contained in the composition A is lower than the curing temperature of the polysiloxane contained in the composition B. . Thus, the polysiloxane in the B layer is not cured during the temperature rising process until the temperature of the A film reaches the decomposition temperature of the binder resin contained in the composition A during the thermal diffusion of the impurity diffusion component. Therefore, the crosslink density between the polysiloxane skeletons in the B layer does not become too high. Therefore, even though the B layer covers the A film during the thermal diffusion of the impurity diffusing component, oxygen reaches the A film, so that the B layer prevents the binder resin in the A film from being thermally decomposed. Absent. As a result, even after the thermal diffusion of the impurity diffusion component, an excessive residue of the A film does not remain on the semiconductor substrate, and a good diffusibility of the impurity diffusion component can be obtained. It is possible to achieve both the effect of suppressing the diffusion of the diffusion component in the air.

The aryl group having 6 to 15 carbon atoms as R ^{1 in the} general formula (1) may be either unsubstituted or substituted, and can be selected according to the characteristics of the composition B. Specific examples of the aryl group having 6 to 15 carbon atoms include phenyl group, p-tolyl group, m-tolyl group, o-tolyl group, p-hydroxyphenyl group, p-styryl group, p-methoxyphenyl group, A naphthyl group is mentioned. Among these, a phenyl group, a p-tolyl group, and an m-tolyl group are particularly preferable.

The alkyl group having 1 to 6 carbon atoms and the alkenyl group having 2 to 10 carbon atoms as R ^{3 in the} general formula (1) may be either unsubstituted or substituted, depending on the characteristics of the composition B. You can choose.

Specific examples of the alkyl group having 1 to 6 carbon atoms as R ³ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, n-hexyl group, trifluoromethyl. Group, 3,3,3-trifluoropropyl group, 3-methoxy-n-propyl group, glycidyl group, 3-glycidoxypropyl group, 3-aminopropyl group, 3-mercaptopropyl group, 3-isocyanatopropyl group Is mentioned. Among these, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a t-butyl group having 4 or less carbon atoms are preferable from the viewpoint of easily eliminating the residue of the A film.

Specific examples of the alkenyl group having 2 to 10 carbon atoms as R ³ include vinyl group, 1-propenyl group, 1-butenyl group, 2-methyl-1-propenyl group, 1,3-butanedienyl group, 3-methoxy group. Examples include a -1-propenyl group, a 3-acryloxypropyl group, and a 3-methacryloxypropyl group. Among these, from the viewpoint of easily eliminating the residue of the A film, a vinyl group having 1 to 4 carbon atoms, 1-propenyl group, 1-butenyl group, 2-methyl-1-propenyl group, 1,3-butanedienyl group, 3 A -methoxy-1-propenyl group is particularly preferred.

The alkoxy group having 1 to 6 carbon atoms and the acyloxy group having 1 to 6 carbon atoms as R ² and R ^{4 in} the general formula (1) may be either unsubstituted or substituted. It can be selected according to. Specific examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group and t-butoxy group. Specific examples of the acyloxy group having 1 to 6 carbon atoms include an acetoxy group, a propionyloxy group, an acryloyloxy group, and a benzoyloxy group.

In the general formula (1), X is a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, It represents either an aryl group having 6 to 15 carbon atoms or a heteroaryl group having 3 to 12 carbon atoms. Y represents any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and an acyl group having 1 to 7 carbon atoms.

(solvent)
The solvent contained in the composition B is not particularly limited, but is preferably a solvent that does not make the A film and the B layer compatible with each other in order to stably form the B layer on the A film. That is, it is preferable that the solvent contained in the composition B is one that prevents the composition A and the composition B from being compatible. For this purpose, the composition A contains a water-soluble binder resin, and the solubility of the water-soluble binder resin in the composition A with respect to the solvent in the composition B is 0.01 [g / mL] or less at 25 ° C. Is preferred. On the A film formed on the semiconductor substrate by the combination of the water-soluble binder resin in the composition A and the solvent in the composition B (a state in which the solvent is volatilized and does not substantially contain the solvent) When the B layer is formed using the composition B, the A film and the composition B are not mixed so as to hinder the film formation. For this reason, the B layer is easily formed stably on the A film.

When polyvinyl alcohol, which is particularly preferable as the water-soluble binder resin in the composition A, is used, specific examples of the solvent of the composition B satisfying the above conditions include γ-butyrolactone, texanol, terpineol, 3-methyl-3-methoxy. Examples include butanol, dimethylformamide, 2-butanol, diethylene glycol monomethyl ether, and the like. Among these, γ-butyrolactone, terpineol, and texanol are preferable.

(Binder resin, thickener, surfactant)
The binder resin and the thickener can be used for the composition B without any particular limitation as long as they have a solubility of 10% by weight or more with respect to the solvent of the composition B. As the binder resin of the composition B, polyvinyl butyral or (meth) acrylic ester resin is particularly preferable. As the thickener of the composition B, polyethylene oxide, polypropylene oxide, and silicone oil are particularly preferable. The surfactant of the composition B is the same as that appropriately contained in the composition A, but the content thereof is, when added to the composition B, 0. 0% of the surfactant contained in the composition A. 0001 to 1% by weight.

When polysiloxane or a siloxane derivative is used for the composition B, silica particles can be added to the composition B for the purpose of improving the masking property of the B layer. In this case, the silica particles preferably have an average particle size of 150 [nm] or less.

(Other additives)
In addition, the composition B can contain a compound that forms a stable bond with an impurity diffusion component or an impurity element. The composition B improves the masking property of the B layer by containing these compounds. Specifically, when the impurity diffusion component contained in the composition A is phosphorus, the additive contained in the composition B is preferably a gallium or aluminum compound. When the impurity diffusion component contained in the composition A is boron, the additive contained in the composition B is preferably a compound containing phosphorus, tantalum, niobium, arsenic or antimony. Since the additive in the composition B forms a stable bond with the impurity diffusion component and the impurity element, it is possible to suppress unintentional impurity diffusion into a semiconductor substrate such as a silicon wafer. It is possible to realize good diffusion without contamination of the impurity diffusion component with respect to the semiconductor substrate.

(Method for forming A film and B layer)
A method for forming the A film and the B layer in the present invention will be described. In this forming method, an A film made of the composition A and a B layer made of the composition B are formed on the semiconductor substrate surface. As a method for forming these A film and B layer, a known method can be used. A composition A is applied on a semiconductor substrate surface to form an A film, and a composition B is formed on the A film. A coating method of forming a B layer by coating is preferably used. Specific examples of the coating method for forming the A film and the B layer include a spin coating method, an ink jet method, a slit coating method, and a screen printing method.

In the formation method of the A film and the B layer using the coating method, in order to stably form the B layer on the A film, for example, the composition A is applied on the semiconductor substrate surface to form the A film. After forming and drying, the B layer is formed by coating the composition B on the dried A film. However, in this formation method, since the coating process and the drying process for forming the A film and the B layer are alternately performed, the total number of processes is increased. In order to reduce the number of steps required for forming the A film and the B layer, thereby reducing the manufacturing cost and tact time of the semiconductor element (and thus the solar cell), the process of forming the A film, It is preferable that the step of forming the B layer is continuously performed without a drying step by heat treatment. For this reason, as a method for applying the composition A and the composition B, a spin coating method or an ink jet method capable of continuously forming the A film and the B layer as described above is preferably used.

When the application of the composition A and the application of the composition B are continuously performed by the spin coating method, the composition A is dropped on the surface of the semiconductor substrate such as a silicon wafer, and then the rotation in the spin coating method (specifically, More preferably, the composition B is continuously dropped without stopping the rotation of the semiconductor substrate. As a result, the A film and the B layer can be sequentially formed on the semiconductor substrate surface, so that the formation of the A film on the semiconductor substrate surface and the formation of the B layer on the A film are performed in one step. It can be carried out. As a result, a reduction in the number of steps necessary for forming the A film and the B layer can be achieved. Also, since the spin coating method is easy to form a uniform film, an A film is uniformly formed on a target region in which a target impurity diffusion component is diffused on the semiconductor substrate surface, and a mask is formed on the A film. There is also an advantage that it is easy to achieve the purpose of reducing the number of steps by uniformly forming the B layer.

In order to suitably use the coating method described above for the coating film forming method of the composition A and the composition B, the boiling point of each solvent contained in each of the composition A and the composition B and each of the compositions A and B The viscosity needs to be suitable for the process using the coating method. For example, when the composition A and the composition B are applied and formed by spin coating, the boiling point of the solvent contained in the composition A is preferably 30 ° C. or higher and 150 ° C. or lower. The boiling point of the solvent contained in the composition B is preferably 30 ° C. or higher and lower than 280 ° C., and more preferably 70 ° C. or higher and lower than 200 ° C. When the composition A and the composition B are formed by coating using an inkjet method, the boiling point of each solvent contained in each of the composition A and the composition B is preferably 100 ° C. or higher and lower than 280 ° C., and 120 ° C. or higher and 200 ° C. More preferably, it is less.

On the other hand, as a method of forming the A film made of the composition A and the B layer made of the composition B on the semiconductor substrate surface, a laminate method is also preferably used. As an example of the method for forming the A film and the B layer by the laminating method, there are the following two methods.

For example, in the first method, the A film previously formed using the composition A on the film is transferred to the semiconductor substrate surface by lamination. Thereafter, the B layer previously formed on the film using the composition B is transferred to the surface of the A film on the semiconductor substrate surface by lamination. Thereby, the A film and the B layer are formed on the semiconductor substrate.

In the second method, a laminate of a B layer formed using the composition B on a film and an A film formed using the composition A on the B layer is formed in advance. The film formed with is laminated on the surface of the semiconductor substrate, and the laminate is transferred to the surface of the semiconductor substrate. Thereby, the A film and the B layer are formed on the semiconductor substrate.

(Each manufacturing method of a semiconductor element and a solar cell)
Each method for manufacturing a semiconductor element and a solar cell according to the present invention will be described below using typical examples. The method for manufacturing a semiconductor device according to the present invention includes a film layer forming step and a diffusion step. The film layer forming step uses an A film, which is an impurity diffusion composition film using a composition A containing an impurity diffusion component, and a composition B containing polysiloxane on a semiconductor substrate. And a B layer that is an air diffusion suppressing layer that suppresses the air diffusion of the impurity diffusion component from the A film. The diffusion step is a step of heat-treating the semiconductor substrate on which these A film and B layer are formed, and diffusing impurity diffusion components from the A film into the semiconductor substrate. The method for manufacturing a solar cell according to the present invention includes such a method for manufacturing a semiconductor element.

As the semiconductor substrate used in each of these manufacturing methods, for example, n-type single crystal silicon having an impurity concentration of 10 ¹⁵ to 10 ¹⁶ [atoms / cm ³ ], polycrystalline silicon, germanium, carbon, etc. A crystalline silicon substrate in which the above elements are mixed. Alternatively, p-type crystalline silicon or a semiconductor substrate other than silicon can be used. Such a semiconductor substrate preferably has a thickness of 50 [μm] to 300 [μm] and an outer shape of an approximately quadrangle with sides of 100 [mm] to 250 [mm]. In addition, in order to remove the slice damage and the natural oxide film on the semiconductor substrate surface, it is preferable to etch the semiconductor substrate surface with a hydrofluoric acid solution or an alkaline solution.

(Embodiment 1)
First, a method for manufacturing a semiconductor element according to Embodiment 1 of the present invention will be described. FIG. 1 is a diagram showing an example of a method for manufacturing a semiconductor element according to Embodiment 1 of the present invention. In the semiconductor element manufacturing method according to the first embodiment, the film layer forming step includes an A film forming step and a B layer forming step using a coating method.

Specifically, as shown in FIG. 1, first, the A film forming step (step ST101) is performed. In this step ST101, the A film 2 is formed by applying the composition A to a predetermined surface of the semiconductor substrate 1 (for example, one surface of both end surfaces in the thickness direction of the semiconductor substrate 1) by the application method described above. It is formed. At this time, on the surface opposite to the surface on which the A film 2 is formed (application surface of the composition A) of the semiconductor substrate 1 (the other surface of both end surfaces in the thickness direction of the semiconductor substrate 1), A protective film may be formed in advance. This protective film can be formed by a technique such as CVD (chemical vapor deposition) or spin-on-glass (SOG). For example, the protective film may be a known film such as a silicon oxide film or a silicon nitride film.

Subsequently, as shown in FIG. 1, a B layer forming step (step ST102) is performed. In this step ST102, the B layer 3 is formed by applying the composition B by the coating method described above on the A film 2 formed on the predetermined surface of the semiconductor substrate 1 in the above-described step ST102. .

In the film layer forming step in the first embodiment, step ST101 and step ST102 shown in FIG. 1 are continuously performed. That is, the A film 2 and the B layer 3 are sequentially formed on the semiconductor substrate 1 without going through a drying process by heat treatment.

Thus, after the A film 2 and the B layer 3 are sequentially formed on the semiconductor substrate 1, a drying process for drying the A film 2 and the B layer 3 may be performed. In this drying step, the composition A before drying constituting the A film 2 and the composition B before drying constituting the B layer 3 are dried. In such a drying step, it is preferable that these composition A and composition B are dried in a range of 50 ° C. to 200 ° C. for 30 seconds to 30 minutes using a hot plate, oven, or the like.

Further, as described above, the coating method used in the A film forming step (step ST101) and the B layer forming step (step ST102) includes a spin coating method, an ink jet method, a slit coating method, a screen printing method, and the like. However, among these, the spin coating method and the ink jet method are preferable.

For example, when the A film 2 and the B layer 3 are formed by a spin coating method, the steps ST101 and ST102 shown in FIG. 1 do not stop the rotation in the spin coating method (specifically, the rotation of the semiconductor substrate 1). It is preferable to carry out continuously.

After the above-described step ST102 is completed, a diffusion step (step ST103) is performed as shown in FIG. In this step ST103, the semiconductor substrate 1 on which the A film 2 and the B layer 3 are formed is heat-treated to diffuse the impurity diffusion component in the semiconductor substrate 1. At this time, the target impurity diffusion component contained in the composition A is thermally diffused from the A film 2 into the semiconductor substrate 1. As a result, a target conductivity type (n-type or p-type) impurity diffusion layer 4 is formed in the semiconductor substrate 1. In parallel with this, the B layer 3 suppresses the diffusion of the target impurity diffusion component from the A film 2 in the air, and the impurity diffusion component of another conductivity type different from the composition A from the outside causes the A film 2. It is restrained from mixing in.

As a heat treatment method in this step ST103, for example, a known method such as electric heating, infrared heating, laser heating, microwave heating or the like can be used. The time and temperature of this heat treatment can be appropriately set so that the diffusion characteristics such as the concentration and diffusion depth of the impurity diffusion component diffused in the semiconductor substrate 1 become desired.

The gas atmosphere for this heat treatment is not particularly limited, but is preferably a mixed gas atmosphere of nitrogen, oxygen, argon, helium, xenon, neon, krypton, or the like. Among these, a mixed gas of nitrogen and oxygen is more preferable, and a mixed gas of nitrogen and oxygen having an oxygen content of 5% by volume or less is particularly preferable. In step ST103, the A film 2 may be baked in the range of 200 ° C. to 750 ° C. before the impurity diffusion layer 4 is formed, if necessary.

After the above-described step ST103 is completed, a removal step (step ST104) is performed as shown in FIG. In this step ST104, the A film 2 and the B layer 3 on the semiconductor substrate 1 are removed by a known etching method. Although the material used for this etching method is not specifically limited, For example, it contains at least 1 sort (s) among hydrogen fluoride, ammonium, phosphoric acid, a sulfuric acid, and nitric acid as an etching component, and contains water, an organic solvent, etc. as other components. Those are preferred. Through the above steps, the target conductivity type impurity diffusion layer 4 can be formed in the semiconductor substrate 1. In this way, the semiconductor element 100 according to the first embodiment is manufactured.

(Embodiment 2)
Next, a method for manufacturing a semiconductor element according to Embodiment 2 of the present invention will be described. FIG. 2A is a diagram illustrating an example of a method of manufacturing a semiconductor element according to Embodiment 2 of the present invention. In the method of manufacturing a semiconductor device according to the second embodiment, a film forming step of forming an impurity diffusion composition film having a conductivity type different from that of the A film on the semiconductor substrate, and forming the A film and the B layer on the semiconductor substrate. A film layer forming step and a diffusion step of diffusing an impurity diffusion component in the semiconductor substrate are included. In the method for manufacturing a semiconductor element according to the second embodiment, the film layer forming step includes an A film forming step and a B layer forming step using a coating method.

Specifically, as shown in FIG. 2A, first, a film formation step (step ST201) is performed. In this step ST201, an impurity diffusion composition film 15 having a conductivity type different from that of the A film 12 is formed on the surface of the semiconductor substrate 11 opposite to the later-described A film 12 (see step ST202 in FIG. 2A). Is done. The formation surface of the impurity diffusion composition film 15 is, for example, one surface of both end surfaces in the thickness direction of the semiconductor substrate 11. The impurity diffusion composition film 15 can be formed by applying an impurity diffusion composition having a conductivity type different from that of the composition A onto the surface of the semiconductor substrate 11 by the application method described above. The impurity diffusion composition constituting the impurity diffusion composition film 15 may be used without limitation as long as it contains an impurity diffusion component having a conductivity type different from that of the composition A and can be formed by the above-described coating method. it can.

Thus, after the impurity diffusion composition film 15 is formed on the surface of the semiconductor substrate 11, a drying step of drying the impurity diffusion composition film 15 may be performed. Further, the impurity diffusion composition film 15 may be baked in the range of 200 ° C. to 750 ° C.

After the above-described step ST201 is completed, the A film forming step (step ST202) is performed as shown in FIG. 2A. In this step ST202, the composition A is applied to a predetermined surface of the semiconductor substrate 11 (in the second embodiment, the other surface of both end surfaces in the thickness direction of the semiconductor substrate 1) by the above-described application method. A film 12 is formed. The surface on which the A film 12 is formed is the surface of the semiconductor substrate 11 opposite to the impurity diffusion composition film 15 as shown in FIG. 2A.

Subsequently, as shown in FIG. 2A, a B layer forming step (step ST203) is performed. In this step ST203, the B layer 13 is formed by applying the composition B to the outer surface of the A film 12 formed on the predetermined surface of the semiconductor substrate 11 by the above-described step ST202 by the above-described coating method. The

In the film layer forming step in the second embodiment, step ST202 and step ST203 shown in FIG. 2A are continuously performed. That is, the A film 12 and the B layer 13 are sequentially formed on the surface of the semiconductor substrate 11 without going through a drying process by heat treatment. At this time, the coating method used in step ST202 and step ST203 is the same as that in the first embodiment (spin coating method, ink jet method, etc.). After the A film 12 and the B layer 13 are sequentially formed on the surface of the semiconductor substrate 11 as described above, a drying process for drying the A film 12 and the B layer 13 may be performed as in the first embodiment. Good.

After the above-described step ST203 is completed, a diffusion step (step ST204) is performed as shown in FIG. 2A. In this step ST204, the semiconductor substrate 11 on which the impurity diffusion composition film 15, the A film 12 and the B layer 13 are formed is heat-treated in the same manner as in the first embodiment, and the impurity diffusion composition film 15 is removed. The impurity diffusion component is diffused into the semiconductor substrate 11 and the impurity diffusion component from the A film 12 is diffused into the semiconductor substrate 11. At this time, the target impurity diffusion component contained in the impurity diffusion composition film 15 is thermally diffused from the impurity diffusion composition film 15 into the semiconductor substrate 11. At the same time, the target impurity diffusion component contained in the A film 12 (composition A) is thermally diffused from the A film 12 into the semiconductor substrate 11. As a result, the impurity diffusion layer 16 from the impurity diffusion composition film 15 and the impurity diffusion layer 14 from the A film 12 are simultaneously formed in the semiconductor substrate 11. The impurity diffusion layer 16 has a target first conductivity type (n-type or p-type). The impurity diffusion layer 14 is of a target second conductivity type (a conductivity type different from the first conductivity type). The impurity diffusion layer 16 and the impurity diffusion layer 14 are respectively formed on both sides in the thickness direction in the semiconductor substrate 11 as shown in FIG. 2A.

After the above-described step ST204 is completed, a removal step (step ST205) is performed as shown in FIG. 2A. In this step ST205, the impurity diffusion composition film 15 formed on one surface of the semiconductor substrate 11, and the A film 12 and the B layer 13 formed on the other surface are the same as those in the first embodiment. It is removed by the same etching method. Through the above steps, a target first conductivity type impurity diffusion layer 16 is formed on one surface side of the semiconductor substrate 11, and a target second conductivity type impurity is formed on the other surface side. A diffusion layer 14 can be formed. In this way, the semiconductor element 200 according to the second embodiment is manufactured. The semiconductor element 200 is suitable as a semiconductor element for a double-sided light receiving solar cell.

In the second embodiment, when the semiconductor substrate 11 on which the impurity diffusion composition film 15 and the A film 12 having different conductivity types are formed is subjected to heat treatment (step ST204 shown in FIG. 2A), the B layer 13 becomes the A film 12 The impurity diffusion component diffused in the air from the impurity diffusion composition film 15 (with a conductivity type different from that of the A film 12) enters the A film 12 while suppressing the target impurity diffusion component from being diffused in the air. It plays a role to suppress. Thereby, n-type impurities and p-type impurities can be diffused into a desired region in the semiconductor substrate 11.

Next, a method for manufacturing a solar cell according to Embodiment 2 of the present invention will be described. FIG. 2B is a diagram illustrating an example of a solar cell manufacturing method according to Embodiment 2 of the present invention. FIG. 2B illustrates a process after manufacturing a semiconductor element 200 (see FIG. 2A) that can be used for manufacturing the solar cell according to the second embodiment.

The method for manufacturing a solar cell according to Embodiment 2 includes the method for manufacturing the semiconductor element 200 shown in FIG. 2A. That is, after manufacturing the semiconductor element 200 as described above, the solar cell according to the second embodiment (double-sided light receiving solar cell) can be manufactured using a known method.

For example, in the method for manufacturing a solar cell according to Embodiment 2, a passivation layer forming step (step ST301) is performed as shown in FIG. 2B following the manufacturing step of the semiconductor element 200 shown in FIG. 2A. In this step ST301, the passivation layer 17 is formed on each of the light receiving surface and the back surface of the semiconductor substrate 11. As a material for the passivation layer 17, a known material can be used. The passivation layer 17 may be a single layer or a plurality of layers. For example, the passivation layer 17 includes a stacked layer of a thermal oxide layer, an aluminum oxide layer, a SiNx layer, and an amorphous silicon layer. The passivation layer 17 can be formed by a vapor deposition method such as a plasma CVD method, an ALD (atomic layer deposition) method, or a coating method.

In the second embodiment, the passivation layer 17 is formed in a partial region on each of the light receiving surface and the back surface of the semiconductor substrate 11. In the semiconductor element 200, the light receiving surface is the surface of the semiconductor substrate 11 on the first conductivity type impurity diffusion layer 16 side. The back surface is a surface of the semiconductor substrate 11 on the second conductivity type impurity diffusion layer 14 side.

After the above-described step ST301 is completed, an electrode formation step (step ST302) is performed as shown in FIG. 2B. In this step ST302, the electrode 18 and the electrode 19 are respectively formed on the light receiving surface and the back surface of the semiconductor substrate 11 in portions where the passivation layer 17 does not exist. For these electrodes 18 and 19, after applying an electrode forming paste to each exposed portion of the impurity diffusion layer 16 or the impurity diffusion layer 14 of the semiconductor substrate 11, the electrode forming paste in each exposed portion is subjected to heat treatment. Can be formed. Through the above steps, the double-sided solar cell 250 according to the second embodiment is manufactured.

(Embodiment 3)
Next, a method for manufacturing a semiconductor element according to Embodiment 3 of the present invention will be described. FIG. 3A is a diagram illustrating an example of a method of manufacturing a semiconductor element according to Embodiment 3 of the present invention. In the method of manufacturing a semiconductor element according to the third embodiment, a film forming step of forming an impurity diffusion composition film having a conductivity type different from that of the A film on the semiconductor substrate, and forming the A film and the B layer on the semiconductor substrate. A film layer forming step and a diffusion step of diffusing an impurity diffusion component in the semiconductor substrate are included. In the method for manufacturing a semiconductor element according to the third embodiment, the film layer forming step includes an A film forming step and a B layer forming step using a coating method.

Embodiment 3 exemplifies a manufacturing method applied when manufacturing a semiconductor element for a back junction solar cell. In a semiconductor element for a back junction solar cell, a p-type impurity diffusion layer and an n-type impurity diffusion layer are formed on the back surface that is the surface opposite to the light receiving surface of the solar cell.

Specifically, as shown in FIG. 3A, first, a film formation step (step ST401) is performed. In this step ST401, an impurity diffusion composition film 25 having a conductivity type different from that of the A film 22 described later is formed on a predetermined surface of the semiconductor substrate 21 (back surface in the solar cell). At this time, a pattern of the impurity diffusion composition film 25 is formed by applying an impurity diffusion composition of the first conductivity type different from the composition A on the back surface of the semiconductor substrate 21. This pattern can be formed by a method appropriately selected from the above-described coating methods such as a screen printing method and an ink jet method. The impurity diffusion composition constituting the impurity diffusion composition film 25 can be used without limitation as long as it contains the first conductivity type impurity diffusion component and can be formed by the above-described coating method.

Thus, after the pattern of the impurity diffusion composition film 25 is formed on the back surface of the semiconductor substrate 21, a drying step of drying the impurity diffusion composition film 25 may be performed. Further, the impurity diffusion composition film 25 may be baked in the range of 200 ° C. to 750 ° C.

After the above-described step ST401 is completed, a first diffusion step (step ST402) is performed as shown in FIG. 3A. In this step ST402, the semiconductor substrate 21 on which the pattern of the impurity diffusion composition film 25 is formed is heat-treated by the same method as in the first embodiment, and the first conductivity type included in the impurity diffusion composition film 25 is obtained. The impurity diffusion component is diffused into the semiconductor substrate 21. At this time, the impurity diffusion component of the first conductivity type is thermally diffused into the semiconductor substrate 21 from the pattern of the heat-treated impurity diffusion composition film 25. As a result, an intended impurity diffusion layer 26 of the first conductivity type is formed along the pattern of the impurity diffusion composition film 25 on the back surface side in the semiconductor substrate 21.

After the above-described step ST402 is completed, an A film forming step (step ST403) is performed as shown in FIG. 3A. In this step ST403, the A film 22 is formed by applying the composition A to the back surface of the semiconductor substrate 21 (the surface on the same side as the impurity diffusion composition film 25) by the application method described above. At this time, the composition A is applied onto the back surface of the semiconductor substrate 21 using the pattern of the impurity diffusion composition film 25 as a mask. Thereby, the A film 22 is formed on the back surface of the semiconductor substrate 21 so as to cover the impurity diffusion composition film 25 without being in contact with the impurity diffusion layer 26 under the pattern.

Subsequently, as shown in FIG. 3A, a B layer forming step (step ST404) is performed. In this step ST404, the B layer 23 is formed by applying the composition B to the outer surface of the A film 22 formed in the above step ST403 by the above-described coating method.

In the film layer forming step in the third embodiment, step ST403 and step ST404 shown in FIG. 3A are continuously performed. That is, the A film 22 and the B layer 23 are sequentially formed on the back surface of the semiconductor substrate 21 without going through a drying process by heat treatment. At this time, the coating method used in step ST403 and step ST404 is the same as that in the first embodiment (spin coating method, ink jet method, etc.). As described above, after the A film 22 and the B layer 23 are sequentially formed on the back surface of the semiconductor substrate 21 as described above, a drying process for drying the A film 22 and the B layer 23 may be performed as in the first embodiment. Good.

After the above-described step ST404 is completed, a second diffusion step (step ST405) is performed as shown in FIG. 3A. In this step ST405, the semiconductor substrate 21 on which the impurity diffusion composition film 25, the A film 22 and the B layer 23 are formed is heat-treated by the same method as in the first embodiment, and the impurity diffusion from the A film 22 is performed. Components are diffused into the semiconductor substrate 21. At this time, the impurity diffusion component of the second conductivity type (conductivity type different from the first conductivity type) contained in the A film 22 (composition A) is changed from the A film 22 to the impurity in the back surface portion of the semiconductor substrate 21. Thermal diffusion is performed in the exposed portion that is not masked by the pattern of the diffusion composition film 25. Thereby, an impurity diffusion layer 24 from the A film 22 is formed in the exposed portion on the back surface of the semiconductor substrate 21. The impurity diffusion layer 24 is of the intended second conductivity type.

After step ST405 described above is completed, a removal step (step ST406) is performed as shown in FIG. 3A. In this step ST406, the pattern of the impurity diffusion composition film 25, the A film 22 and the B layer 23 formed on the back surface of the semiconductor substrate 21 are removed by the same etching method as in the first embodiment. Through the above steps, the target first conductivity type impurity diffusion layer 26 and the second conductivity type impurity diffusion layer 24 can be formed on the back side of the semiconductor substrate 21. In this way, the semiconductor element 300 according to the third embodiment is manufactured. This semiconductor element 300 is suitable as a semiconductor element for a back junction solar cell.

In the third embodiment, when the second conductivity type impurity diffusion layer 24 is formed (step ST405 shown in FIG. 3A), the B layer 23 is formed from the A film 22 with the target second conductivity type impurity diffusion component. Suppresses air diffusion. Therefore, the impurity diffusion component diffused in the air from the A film 22 is intended on the light receiving surface of the semiconductor substrate 21 (the surface opposite to the surface (back surface) on which the two types of impurity diffusion layers 24 and 26 are formed). It is possible to prevent it from diffusing.

Next, a method for manufacturing a solar cell according to Embodiment 3 of the present invention will be described. FIG. 3B is a diagram illustrating an example of a solar cell manufacturing method according to Embodiment 3 of the present invention. FIG. 3B shows a process after manufacturing a semiconductor element 300 (see FIG. 3A) that can be used for manufacturing the solar cell according to the third embodiment.

The method for manufacturing a solar cell according to Embodiment 3 includes the method for manufacturing the semiconductor element 300 shown in FIG. 3A. That is, after manufacturing the semiconductor element 300 as described above, the solar cell according to Embodiment 3 (back junction solar cell) can be manufactured using a known method.

For example, in the method for manufacturing a solar cell according to Embodiment 3, a passivation layer forming step (step ST501) is performed as shown in FIG. 3B following the manufacturing step of the semiconductor element 300 shown in FIG. 3A. In this step ST501, the passivation layer 27 is formed on the back surface of the semiconductor substrate 21. A known material can be used as the material of the passivation layer 27. The passivation layer 27 may be a single layer or a plurality of layers. For example, the passivation layer 27 includes a stacked layer of a thermal oxide layer, an aluminum oxide layer, a SiNx layer, and an amorphous silicon layer. The passivation layer 27 can be formed by a vapor deposition method such as a plasma CVD method, an ALD (atomic layer deposition) method, or a coating method. In the third embodiment, the passivation layer 27 is formed in a partial region on the back surface of the semiconductor substrate 21 (the surface on the side where the two types of impurity diffusion layers 24 and 26 are formed).

After the above-described step ST501 is completed, an electrode formation step (step ST502) is performed as shown in FIG. 3B. In this process ST502, the electrode 28 and the electrode 29 are each formed in each part in which the passivation layer 27 does not exist among the back surfaces of the semiconductor substrate 21. The electrode 28 and the electrode 29 are formed by applying an electrode forming paste to each exposed portion of the impurity diffusion layer 26 or the impurity diffusion layer 24 in the back surface of the semiconductor substrate 21 and then heating the electrode forming paste in each exposed portion. It can be formed by processing. Through the above steps, the back junction solar cell 350 according to the third embodiment is manufactured.

Each method for manufacturing a semiconductor element and a solar cell according to the present invention is not limited to the above-described first to third embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. Embodiments to which such modifications are added are also included in the scope of the present invention. For example, in the first to third embodiments described above, the film layer forming step including the A film forming step and the B layer forming step using the coating method is exemplified, but the present invention is not limited to this. Absent. In the film layer forming step described above, a laminate of the A film formed beforehand using the composition A and the B layer formed using the composition B on the A film is laminated on a predetermined surface of the semiconductor substrate. It may be of a laminate type including the step of forming the substrate.

In addition, a method for manufacturing a semiconductor device according to the present invention includes a photovoltaic device such as a solar cell, or a semiconductor device in which an impurity diffusion layer is formed on the surface of a semiconductor substrate, such as a transistor array, a diode array, a photodiode array, a transformer. It can also be applied to a producer.

Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples. Further, among the compounds used in the following examples, those using abbreviations are defined as follows.

“B ₂ O ₃ ” is diboron trioxide. “PVA” is polyvinyl alcohol. “GBL” is γ-butyrolactone. “MMB” is 3-methoxy-3-methyl-1-butanol. “PGME” is propylene glycol monomethyl ether. “DMF” is N, N-dimethylformamide. “MeTMS” is methyltrimethoxysilane. “PhTMS” is phenyltrimethoxysilane.

FIG. 4 is a diagram for explaining each evaluation of peelability, diffusibility, diffusion uniformity and barrier property in the examples of the present invention. FIG. 5 is a diagram illustrating air diffusivity evaluation in the example of the present invention. Each evaluation in a present Example is demonstrated with reference suitably to FIG.

(Peelability evaluation)
In the peelability evaluation, the peelability of the A film from the semiconductor substrate surface is evaluated. In the peelability evaluation, a silicon wafer 31 (see FIG. 4), which is an example of a semiconductor substrate, is an n-type silicon wafer subjected to texture processing of 156 mm × 156 mm (manufactured by Electronics End Materials Corporation, resistance value 0.5− 6.0 [Ω · cm]). The silicon wafer 31 was immersed in a 5 wt% hydrofluoric acid aqueous solution for 1 minute, washed with water, and dried by air blowing.

Next, the composition A was applied to the silicon wafer 31 by a known spin coating method so that the film thickness after drying was about 500 nm, and an A film 32 shown in a state a1 in FIG. 4 was formed. Subsequently, the composition B was applied on the A film 32 by a known spin coating method so that the film thickness after drying was about 500 nm, and the B layer 33 shown in the state a1 in FIG. 4 was formed. . Thereafter, the silicon wafer 31 was pre-baked at 150 ° C. for 1 minute. Thus, an impurity diffusion composition coated substrate 30 having the A film 32 and the B layer 33 on the surface of the n-type silicon wafer 31 as shown in the state a1 of FIG. 4 was obtained.

Next, the obtained impurity diffusion composition coated substrate 30 is placed in a diffusion furnace and maintained at 900 ° C. for 30 minutes in an atmosphere of nitrogen: oxygen = 99: 1 (volume ratio). The impurity diffusion component was thermally diffused into the wafer 31. After thermal diffusion, the impurity diffusion composition-coated substrate 30 was immersed in a 5 wt% hydrofluoric acid aqueous solution at 23 ° C. for 1 minute, and the A film 32 and the B layer 33 were peeled from the silicon wafer 31. After peeling, the silicon wafer 31 is immersed in pure water and washed, and the residue of the A film 32 adhering to the surface (hereinafter referred to as “surface deposit” as appropriate) is visually observed on the surface of the silicon wafer 31. The presence or absence was observed.

In the peelability evaluation of this example, among the silicon wafers 31 to be evaluated, the surface deposits can be visually confirmed after being immersed for 1 minute, and the surface deposits cannot be removed by rubbing with a waste. ) ”. Surface deposits could be confirmed visually after immersion for 1 minute, but those that could be removed by rubbing with a waste were judged as “bad”. Those in which the surface deposits could not be visually confirmed after immersion for more than 30 seconds within 1 minute were judged as “good”. Those whose surface deposits could not be visually confirmed after immersion for 30 seconds or less were determined as “excellent”. From the viewpoint of manufacturing tact time, the combination of the silicon wafer 31 and the A film 32 can be used even if the peelability is good, but the peelability is preferably excellent.

(Diffusion evaluation)
The diffusivity evaluation is to evaluate the diffusibility of the impurity diffusion component from the A film into the semiconductor substrate. In the diffusivity evaluation, p / n determination is performed on the silicon wafer 31 after diffusion used in the above-described peelability evaluation using a p / n determination machine, and the surface of the diffusion portion of the impurity diffusion component in the silicon wafer 31 The resistance was measured using a four-probe type surface resistance measuring device RT-70V (manufactured by Napson Co., Ltd.), and the measured value was used as the sheet resistance value. The sheet resistance value is an index of the diffusibility of the impurity diffusion component in the semiconductor substrate. A smaller sheet resistance value means a larger diffusion amount of the impurity diffusion component. In the diffusivity evaluation of this example, if the sheet resistance value was 40 to 60 [Ω / □], it was determined as excellent. If the sheet resistance value was 60 to 80 [Ω / □], it was judged as good. If the sheet resistance value was 80 to 100 [Ω / □], it was determined as bad (impossible). If the sheet resistance value exceeded 100 [Ω / □], it was determined to be worse.

(Diffusion uniformity evaluation)
In the diffusion uniformity evaluation, the diffusion uniformity of impurity diffusion components from the A film into the semiconductor substrate is evaluated. In the diffusion uniformity evaluation, the surface of the diffusion portion of the impurity diffusion component is used for the silicon wafer 31 after diffusion used for the measurement of the sheet resistance value, using a secondary ion mass spectrometer IMS7f (manufactured by Camera). The concentration distribution was measured. From the obtained surface concentration distribution, 10 surface concentrations were read at intervals of 100 μm, and “standard deviation / average”, which was the ratio of the average to the standard deviation, was calculated. In the diffusivity evaluation of this example, if “standard deviation / average” was 0.3 or less, it was determined as excellent. If “standard deviation / average” was more than 0.3 and 0.6 or less, it was judged as good. When “standard deviation / average” was more than 0.6 and 1.0 or less, it was judged as bad (impossible). If “standard deviation / average” exceeded 1.0, it was determined to be worse. The variation in the surface concentration of the impurity diffusing component greatly affects the power generation efficiency, and therefore is most preferably excellent.

(Barrier property evaluation)
Barrier property evaluation evaluates the barrier property with respect to the impurity diffusion component of B layer. In the barrier property evaluation, a silicon wafer 41 different from the silicon wafer 31 used for the above-described evaluation impurity diffusion composition coated substrate 30 (see state a1 in FIG. 4) is prepared, as shown in state b1 in FIG. In addition, an impurity diffusion composition film 45 having a conductivity type different from that of the A film 32 was formed on the surface of the silicon wafer 41. Specifically, an impurity diffusion composition having a conductivity type different from that of the A film 32 was applied to the silicon wafer 41 by a known spin coating method so that the film thickness after drying was about 500 nm. This impurity diffusion composition was an n-type composition A-3 or a p-type composition A-1 described later. After the application, the silicon wafer 41 was pre-baked at 140 ° C. for 5 minutes, whereby an impurity diffusion composition film 45 was formed on the surface of the silicon wafer 41. In this way, an impurity diffusion composition coated substrate 40 as shown in the state b1 in FIG. 4 was obtained.

Subsequently, as shown in a state c1 in FIG. 4, the impurity diffusion composition coated substrate 30 which is a silicon wafer for evaluation and the impurity diffusion composition coated substrate 40 having a different conductivity type are spaced apart by 3 mm. It was placed in an electric furnace in a face-to-face state. At this time, the B layer 33 of the impurity diffusion composition coated substrate 30 and the impurity diffusion composition film 45 of the impurity diffusion composition coated substrate 40 were made to face each other. Then, in an atmosphere of nitrogen: oxygen = 99: 1 (volume ratio), the temperature is maintained at 900 ° C. for 30 minutes to thermally diffuse the impurity diffusion component from the A film 32 into the silicon wafer 31 and the impurity diffusion composition film 45. Then, the impurity diffusion component was thermally diffused into the silicon wafer 41. As a result, as shown in the state d1 of FIG. 4, the impurity diffusion layer 34 is formed in the silicon wafer 31 of the impurity diffusion composition coated substrate 30, and the impurity diffusion is diffused in the silicon wafer 41 of the impurity diffusion composition coated substrate 40. Layer 46 was formed.

After thermal diffusion, each of the impurity diffusion composition-coated substrates 30 and 40 was immersed in a 5% by mass hydrofluoric acid aqueous solution at 23 ° C. for 1 minute. Thus, the A film 32 and the B layer 33 were removed from the silicon wafer 31, and the cured impurity diffusion composition film 45 was removed from the silicon wafer 41 (see the state d1 and the state e1 in FIG. 4).

Thereafter, the surface concentration distribution of phosphorus atoms and boron atoms was measured for the silicon wafer 31 for evaluation using a secondary ion mass spectrometer IMS7f (manufactured by Camera). The barrier of the B layer 33 against different impurities diffused in the air from the opposite impurity diffusion composition film 45 is lower when the surface concentration of the different impurities on the surface of the silicon wafer 31 (surface on which the impurity diffusion layer 34 is formed) is lower. It means that the nature is high. The “heterogeneous impurity” referred to here is an impurity diffusion component having a conductivity type different from that of the impurity diffusion layer 34 in the silicon wafer 31, and is included in the impurity diffusion composition film 45. In the barrier property evaluation of this example, if the surface concentration of the obtained phosphorus atom or boron atom was 10 ¹⁷ or less, it was determined to be excellent. If this surface concentration was more than 10 ¹⁷ and less than 10 ¹⁸ , it was judged as good. If this surface concentration exceeded 10 ¹⁸ , it was judged as bad (impossible).

(Air diffusion evaluation)
In the air diffusivity evaluation, the function of suppressing the diffusion of impurities in the air by the B layer is evaluated. In the air diffusibility evaluation, an impurity diffusion composition coating substrate 30 for evaluation shown in state a2 in FIG. 5 and a silicon wafer 51 (no coating film formed) shown in state b2 in FIG. 5 are prepared. Then, as shown in the state c2 in FIG. At this time, the B layer 33 of the impurity diffusion composition coated substrate 30 and the silicon wafer 51 were made to face each other. Thereafter, in the same manner as the barrier property evaluation method described above, the impurity diffusion component is thermally diffused from the A film 32 into the silicon wafer 31, whereby the impurity diffusion layer is formed in the silicon wafer 31 of the impurity diffusion composition-coated substrate 30. Next, the A film 32 and the B layer 33 were removed from the silicon wafer 31 (see the state d2 and the state e2 in FIG. 5).

In the air diffusivity evaluation of this example, the surface concentration distribution of phosphorus atoms or boron atoms was measured for the uncoated silicon wafer 51 that was faced using a secondary ion mass spectrometer IMS7f (manufactured by Camera). . A lower surface concentration of phosphorus atoms or boron atoms in the facing silicon wafer 51 means that there is less air diffusion of impurity diffusion components from the A film 32. If the surface concentration of the obtained phosphorus atom or boron atom was 10 ¹⁷ or less, it was determined as excellent. If this surface concentration was more than 10 ¹⁷ and less than 10 ¹⁸ , it was judged as good. If this surface concentration exceeded 10 ¹⁸ , it was judged as bad (impossible).

(Tact time evaluation)
The tact time evaluation is to evaluate the time required to form the A film and the B layer on the semiconductor substrate. In this embodiment, the tact time is the time required from the start of the step of forming the A film 32 on the silicon wafer 31 to the end of the step of forming the B layer 33 on the A film 32. In the tact time evaluation of this example, if the tact time was less than 30 seconds, it was determined to be good. If the tact time was 30 seconds or more, it was determined as bad (impossible).

(Measurement of weight average molecular weight of polysiloxane)
The weight average molecular weight of the polysiloxane was determined by polystyrene conversion using GPC (HLC-8220 GPC manufactured by Tosoh Corporation) after filtering the sample with a membrane filter having a pore diameter of 0.45 μm. At this time, the developing solvent was tetrahydrofuran, and the developing speed was 0.4 [mL / min]. The column was TSKgelSuperHM-H manufactured by Tosoh Corporation.

<Example 1>
(Preparation of Composition A)
In preparation of composition A in Example 1, 20.8 g of PVA (manufactured by Wako Pure Chemicals, degree of polymerization 500) and 144 g of water were charged into a 500 mL three-necked flask, and the temperature was raised to 80 ° C. while stirring. After stirring for 1 hour, 231.6 g of MMB (manufactured by Kuraray Co., Ltd.) and 3.6 g of B ₂ O ₃ were added and stirred at 80 ° C. for 1 hour. Subsequently, the obtained solution was cooled to 40 ° C., and 0.12 g of a fluorosurfactant (Megafac F477 manufactured by Dainippon Ink & Chemicals, Inc.) was added thereto and stirred for 30 minutes. As a result, a composition A-1 was obtained as the composition A of Example 1.

(Preparation of Composition B)
In the preparation of composition B in Example 1, 164.93 g (1.21 mol) of KBM-13 (methyltrimethoxysilane) and 204.07 g of KBM-103 (phenyltrimethoxysilane) were placed in a 500 mL three-necked flask. 1.21 mol) and 36.03 g of GBL (manufactured by Mitsubishi Chemical Corporation) were charged, and an aqueous solution in which 4.50 g of formic acid was dissolved in 130.76 g of water was added over 30 minutes while stirring at 40 ° C. After completion of dropping, the resulting solution was stirred at 40 ° C. for 1 hour, then heated to 70 ° C. and stirred for 30 minutes. Thereafter, the temperature of the oil bath was raised to 115 ° C. One hour after the start of temperature increase, the internal temperature of this solution reached 100 ° C., and from this time, this solution was heated and stirred (internal temperature was 100 ° C. to 110 ° C.). The solution thus obtained was cooled in an ice bath to obtain a polysiloxane solution (PhTMS (50) / MeTMS (50)). “PhTMS (50) / MeTMS (50)” means that the ratio of PhTMS to MeTMS in the polysiloxane is 50:50. The same applies to the following.

The resulting polysiloxane solution had a solid content concentration of 39.8% by weight and a weight average molecular weight (Mw) of 2900. A silicone surfactant (BYK333) is added to a solution of polysiloxane (4.39 g) and GBL (12.55 g) synthesized as described above so as to be 300 ppm with respect to the whole solution, and becomes uniform. Stir well. As a result, a composition B-1 was obtained as the composition B of Example 1.

(Production of evaluation silicon wafer)
In the production of the silicon wafer for evaluation in Example 1, an n-type silicon wafer subjected to texture processing of 156 mm × 156 mm (manufactured by Electronics End Materials Corporation, resistance value 0.5-6.0 [Ω · cm]) Was immersed in a 5 wt% hydrofluoric acid aqueous solution for 1 minute, washed with water, and dried by air blowing. Next, the composition A-1 was applied to the n-type silicon wafer by a known spin coating method so that the film thickness after drying was about 500 nm to form an A film. Subsequently, the composition B-1 was applied on the A film by a known spin coating method so that the film thickness after drying was about 500 nm to form a B layer. Thus, the silicon wafer for evaluation of Example 1 was obtained.

In Example 1, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusivity was performed using the obtained silicon wafer for evaluation. As a result, in Example 1, as shown in Table 2 described later, all of these evaluation items were particularly good.

<Example 2>
(Preparation of Composition A)
In the preparation of the composition A in Example 2, a composition A-1 was obtained in the same manner as in Example 1 described above.

(Preparation of Composition B)
In the preparation of composition B in Example 2, 59.49 g (0.30 mol) of phenyltrimethoxysilane, PL-2L-IPA (silica IPA dispersion, silica average particle diameter, manufactured by Fuso Chemical Co., Ltd.) was placed in a 500 mL three-necked flask. 17nm silica concentration 25.4wt%) and 165.57g (0.70mol (SiO ₂ conversion)), PGME and 133.07g charged, under stirring at room temperature, water required formic acid 3.04g hydrolysis of the monomers A formic acid aqueous solution dissolved in (16.20 g) was added over 30 minutes. Next, this three-necked flask was immersed in a 70 ° C. oil bath and stirred for 1 hour, and then the oil bath was heated to 130 ° C. over 30 minutes. One hour after the start of the temperature increase, the internal temperature of the solution in the three-necked flask reached 100 ° C., and the solution was heated and stirred for 3 hours (the internal temperature was 100 ° C. to 118 ° C.). During the reaction, a total of 147.3 g of methanol, IPA, water and formic acid as by-products were distilled out.

PGME was added to the PGME solution of polysiloxane (PhTMS (100) / MeTMS (0)) thus obtained so that the solid content concentration of polysiloxane was 40% by weight. As a result, a composition B-2 was obtained as the composition B of Example 2.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 2, the evaluation silicon wafer of Example 2 was prepared in the same manner as in Example 1 except that the composition B-2 was used instead of the composition B-1. Obtained.

In Example 2, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained silicon wafer for evaluation. As a result, in Example 2, as shown in Table 2, all of these evaluation items were good.

<Example 3>
(Preparation of Composition A)
In the preparation of the composition A in Example 3, a composition A-2 was obtained in the same manner as in Example 1 except that PGME (manufactured by KH Neochem) was used instead of MMB as a solvent.

(Preparation of Composition B)
In the preparation of the composition B in Example 3, a composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 3, the evaluation silicon wafer of Example 3 was prepared in the same manner as in Example 1 except that the composition A-2 was used instead of the composition A-1. Obtained.

In Example 3, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained silicon wafer for evaluation. As a result, in Example 3, as shown in Table 2, all of these evaluation items were particularly good.

<Example 4>
(Preparation of Composition A)
In the production of the composition A in Example 4, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of the composition B in Example 4, a composition B-2 was obtained in the same manner as in Example 2 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 4, the evaluation silicon wafer of Example 4 was prepared in the same manner as in Example 3 described above, except that the composition B-2 was used instead of the composition B-1. Obtained.

In Example 4, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusivity was performed using the obtained silicon wafer for evaluation. As a result, in Example 4, as shown in Table 2, all of these evaluation items were good.

<Example 5>
(Composition A)
In Example 5, PBF (Tokyo Ohka Kogyo Co., Ltd. paste containing p-type impurities) was used as the composition A.

(Preparation of Composition B)
In the preparation of the composition B in Example 5, a composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 5, the evaluation silicon wafer of Example 5 was obtained in the same manner as in Example 1 except that PBF was used instead of the composition A-1.

In Example 5, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusivity was performed using the obtained evaluation silicon wafer. As a result, in Example 5, as shown in Table 2, all of these evaluation items were particularly good.

<Example 6>
(Composition A)
In Example 6, PBF (manufactured by Tokyo Ohka Kogyo Co., Ltd., paste containing p-type impurities) was used as the composition A.

(Preparation of Composition B)
In the preparation of the composition B in Example 6, a composition B-2 was obtained in the same manner as in Example 2 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 6, the evaluation silicon wafer of Example 6 was obtained in the same manner as in Example 2 described above, except that PBF was used instead of Composition A-1.

In Example 6, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Example 6, as shown in Table 2, all of these evaluation items were good.

<Example 7>
(Preparation of Composition A)
In making the compositions A of Example 7, three-necked flask 500 mL, 6 g phosphoric acid (H ₃ PO _4, manufactured by Wako Pure Chemical Industries, Ltd.) and, with ethanol 193 g (manufactured by Wako Pure Chemical Industries, Ltd.) , 100 g of water was added, and the mixture was stirred at room temperature for 30 minutes to obtain a composition A-3.

(Preparation of Composition B)
In the preparation of the composition B in Example 7, a composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 7, the evaluation silicon wafer of Example 7 was prepared in the same manner as in Example 1 described above except that the composition A-3 was used instead of the composition A-1. Obtained.

In Example 7, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained silicon wafer for evaluation. As a result, in Example 7, as shown in Table 2, the diffusibility and diffusion uniformity were good, and the peelability, barrier property, and air diffusibility were particularly good.

<Example 8>
(Preparation of Composition A)
In the preparation of the composition A in Example 8, a composition A-3 was obtained in the same manner as in Example 7 described above.

(Preparation of Composition B)
In the preparation of the composition B in Example 8, a composition B-2 was obtained in the same manner as in Example 2 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 8, the evaluation silicon wafer of Example 8 was prepared in the same manner as in Example 2 described above, except that the composition A-3 was used instead of the composition A-1. Obtained.

In Example 8, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Example 8, as shown in Table 2, all of these evaluation items were good.

<Example 9>
(Preparation of Composition A)
In the preparation of the composition A in Example 9, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of Composition B in Example 9, Composition B-3 was obtained in the same manner as in Example 1 described above except that the composition of polysiloxane was PhTMS (40) / MeTMS (60). The polysiloxane solution used had a weight average molecular weight (Mw) of 3100.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 9, the evaluation silicon wafer of Example 9 was prepared in the same manner as in Example 3 described above except that the composition B-3 was used instead of the composition B-1. Obtained.

In Example 9, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained silicon wafer for evaluation. As a result, in Example 9, as shown in Table 2, all of these evaluation items were particularly good.

<Example 10>
(Preparation of Composition A)
In the preparation of the composition A in Example 10, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of the composition B in Example 10, a composition B-4 was obtained in the same manner as in Example 1 except that the composition of polysiloxane was PhTMS (90) / MeTMS (10). The polysiloxane solution used had a weight average molecular weight (Mw) of 2300.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 10, the evaluation silicon wafer of Example 10 was prepared in the same manner as in Example 3 described above, except that the composition B-4 was used instead of the composition B-1. Obtained.

In Example 10, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusivity was performed using the obtained evaluation silicon wafer. As a result, in Example 10, as shown in Table 2, all of these evaluation items were particularly good.

<Example 11>
(Preparation of Composition A)
In the preparation of the composition A in Example 11, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of the composition B in Example 11, a composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 11, composition A-2 was applied to the same silicon wafer as in Example 1 by a known spin coating method so that the film thickness after drying was about 500 nm. A film was formed. Subsequently, the composition B-1 was applied on the A film by a known spin coating method so that the film thickness after drying was about 200 nm to form a B layer. In this way, an evaluation silicon wafer of Example 11 was obtained.

In Example 11, using the obtained silicon wafer for evaluation, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed. As a result, in Example 11, as shown in Table 2, all of these evaluation items were particularly good.

<Example 12>
(Preparation of Composition A)
In the preparation of the composition A in Example 12, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of the composition B in Example 12, a composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 12, the composition A-2 was applied to the same silicon wafer as in Example 1 by a known spin coating method so that the film thickness after drying was about 500 nm. A film was formed. Subsequently, the composition B-1 was applied on the A film by a known spin coating method so that the film thickness after drying was about 2000 nm to form a B layer. In this way, an evaluation silicon wafer of Example 12 was obtained.

In Example 12, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusivity was performed using the obtained silicon wafer for evaluation. As a result, in Example 12, as shown in Table 2, all of these evaluation items were particularly good.

<Example 13>
(Preparation of Composition A)
In the preparation of the composition A in Example 13, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of the composition B in Example 13, a composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Example 13, the A film (film thickness of about 500 nm) formed on the film using the composition A-2 was transferred onto the silicon wafer by lamination. Thereafter, the B layer (having a film thickness of about 500 nm) formed on the film using the composition B-1 was transferred onto a silicon wafer on which the A film was formed by lamination. Thereby, the A film and the B layer were formed on the silicon wafer. In this way, an evaluation silicon wafer of Example 13 was obtained.

In Example 13, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusivity was performed using the obtained silicon wafer for evaluation. As a result, in Example 13, as shown in Table 2, all of these evaluation items were particularly good.

<Comparative Example 1>
(Preparation of Composition A)
In preparation of Composition A in Comparative Example 1, 2% by weight of tributyl borate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to Composition B-1 to obtain Composition A-4.

(Preparation of Composition B)
In the preparation of Composition B in Comparative Example 1, Composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 1, the evaluation silicon wafer of Comparative Example 1 was prepared in the same manner as in Example 1 described above except that the composition A-4 was used instead of the composition A-1. Obtained.

In Comparative Example 1, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Comparative Example 1, as shown in Table 2, the peelability, diffusibility, and diffusion uniformity were poor.

<Comparative example 2>
(Preparation of Composition A)
In the preparation of Composition A in Comparative Example 2, Composition A-4 was obtained in the same manner as in Comparative Example 1 described above.

(Preparation of Composition B)
In the preparation of Composition B in Comparative Example 2, Composition B-2 was obtained in the same manner as in Example 2 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 2, the evaluation silicon wafer of Comparative Example 2 was prepared in the same manner as in Example 2 described above, except that the composition A-4 was used instead of the composition A-1. Obtained.

In Comparative Example 2, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Comparative Example 2, as shown in Table 2, the peelability, diffusibility, and diffusion uniformity were poor.

<Comparative Example 3>
(Preparation of Composition A)
In the preparation of the composition A in Comparative Example 3, a composition A-1 was obtained in the same manner as in Example 1 described above.

(Preparation of Composition B)
In the preparation of Composition B in Comparative Example 3, a 5 wt% PGME solution of acrylic resin (KC-7000, Kyoeisha Chemical Co., Ltd.) was prepared. As a result, a composition B-5 was obtained as the composition B of Comparative Example 3.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 3, the evaluation silicon wafer of Comparative Example 3 was prepared in the same manner as in Example 1 described above except that the composition B-5 was used instead of the composition B-1. Obtained.

In Comparative Example 3, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained silicon wafer for evaluation. As a result, in Comparative Example 3, as shown in Table 2, all of these evaluation items were defective.

<Comparative example 4>
(Composition A)
In Comparative Example 4, PBF (Tokyo Ohka Kogyo Co., Ltd. paste containing p-type impurities) was used as the composition A.

(Preparation of Composition B)
In the preparation of Composition B in Comparative Example 4, Composition B-5 was obtained in the same manner as Comparative Example 3 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 4, the evaluation silicon wafer of Comparative Example 4 was obtained in the same manner as in Comparative Example 3 described above, except that PBF was used instead of Composition A-1.

In Comparative Example 4, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Comparative Example 4, as shown in Table 2, all of these evaluation items were defective.

<Comparative Example 5>
(Preparation of Composition A)
In the preparation of the composition A in Comparative Example 5, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of Composition B in Comparative Example 5, Composition B-6 was obtained in the same manner as in Example 1 except that the composition of polysiloxane was PhTMS (30) / MeTMS (70). The polysiloxane solution used had a weight average molecular weight (Mw) of 3400.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 5, the evaluation silicon wafer of Comparative Example 5 was prepared in the same manner as in Example 3 described above, except that the composition B-6 was used instead of the composition B-1. Obtained.

In Comparative Example 5, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained silicon wafer for evaluation. As a result, in Comparative Example 5, as shown in Table 2, all of these evaluation items were good.

<Comparative Example 6>
(Preparation of Composition A)
In the preparation of the composition A in Comparative Example 6, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of Composition B in Comparative Example 6, Composition B-7 was obtained in the same manner as in Example 1 except that the composition of polysiloxane was PhTMS (95) / MeTMS (5). The weight average molecular weight (Mw) of the polysiloxane solution used was 2200.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 6, the evaluation silicon wafer of Comparative Example 6 was prepared in the same manner as in Example 3 described above, except that the composition B-7 was used instead of the composition B-1. Obtained.

In Comparative Example 6, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Comparative Example 6, as shown in Table 2, all of these evaluation items were good.

<Comparative Example 7>
(Preparation of Composition A)
In the preparation of the composition A in Comparative Example 7, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of Composition B in Comparative Example 7, Composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 7, Composition A-2 was applied to the same silicon wafer as in Example 1 by a known spin coating method so that the film thickness after drying was about 500 nm. A film was formed. Subsequently, the composition B-1 was applied on the A film by a known spin coating method so that the film thickness after drying was about 100 nm to form a B layer. In this manner, an evaluation silicon wafer of Comparative Example 7 was obtained.

In Comparative Example 7, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Comparative Example 7, as shown in Table 2, the barrier property and the air diffusion property were poor.

<Comparative Example 8>
(Preparation of Composition A)
In the preparation of the composition A in Comparative Example 8, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of Composition B in Comparative Example 8, Composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 8, the composition A-2 was applied to the same silicon wafer as in Example 1 by a known spin coating method so that the film thickness after drying was about 500 nm. A film was formed. Subsequently, the composition B-1 was applied on the A film by a known spin coating method so that the film thickness after drying was about 3000 nm to form a B layer. Thus, the silicon wafer for evaluation of Comparative Example 8 was obtained.

In Comparative Example 8, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Comparative Example 8, as shown in Table 2, the peelability, diffusibility, and diffusion uniformity were poor.

<Comparative Example 9>
(Preparation of Composition A)
In the preparation of the composition A in Comparative Example 9, 2% by weight of B ₂ O ₃ was added to the composition B-2 to obtain a composition A-5.

(Preparation of Composition B)
In the preparation of the composition B in Comparative Example 9, a composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 9, the evaluation silicon wafer of Comparative Example 9 was prepared in the same manner as in Example 1 described above except that the composition A-5 was used instead of the composition A-1. Obtained.

In Comparative Example 9, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained silicon wafer for evaluation. As a result, in Comparative Example 9, as shown in Table 2, the peelability, diffusibility, and diffusion uniformity were poor.

<Comparative Example 10>
(Preparation of Composition A)
In the preparation of the composition A in Comparative Example 10, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of Composition B in Comparative Example 10, Composition B-8 was obtained in the same manner as in Example 1 described above except that DMF was used instead of GBL.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 10, the evaluation silicon wafer of Comparative Example 10 was prepared in the same manner as in Example 3 described above, except that the composition B-8 was used instead of the composition B-1. Obtained.

In Comparative Example 10, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Comparative Example 10, as shown in Table 2, all of these evaluation items were defective.

<Comparative Example 11>
(Preparation of Composition A)
In the preparation of the composition A in Comparative Example 11, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of the composition B in Comparative Example 11, a composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 11, in the same manner as in Example 1 described above, except that a drying step by heat treatment was provided between the step of forming the A film and the step of forming the B layer. A silicon wafer for evaluation of Comparative Example 11 was obtained.

In Comparative Example 11, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Comparative Example 11, as shown in Table 2, all of these evaluation items were good, but the tact time was inferior to that of Example 1.

<Comparative Example 12>
(Preparation of Composition A)
In the preparation of the composition A in Comparative Example 12, a composition A-2 was obtained in the same manner as in Example 3 described above.

(Preparation of Composition B)
In the preparation of the composition B in Comparative Example 12, a composition B-1 was obtained in the same manner as in Example 1 described above.

(Production of evaluation silicon wafer)
In the production of the evaluation silicon wafer in Comparative Example 12, Example 1 described above except that a step of stopping rotation in the spin coating method was provided between the step of forming the A film and the step of forming the B layer. In the same manner as described above, an evaluation silicon wafer of Comparative Example 12 was obtained.

In Comparative Example 12, each evaluation of peelability, diffusibility, diffusion uniformity, barrier property, and air diffusibility was performed using the obtained evaluation silicon wafer. As a result, in Comparative Example 12, as shown in Table 2, all of these evaluation items were good, but the tact time was inferior to that of Example 1.

Various information regarding the composition A and the composition B in each of the above-described Examples 1 to 13 is shown in Table 1A. In addition, various information regarding the composition A and the composition B in each of the above-described Comparative Examples 1 to 12 is shown in Table 1B. In Table 1A and Table 1B, “Name” in the “Composition A” column indicates the name of the composition A used for forming the A film. “Composition” in the “Composition A” column indicates an impurity (impurity diffusion component), a binder resin, and a solvent contained in the composition A. “Formation method” in the “Composition A” column indicates a method of forming an A film using the composition A. “Name” in the “Composition B” column indicates the name of the composition B used for forming the B layer. “Composition” in the “Composition B” column indicates the air diffusion inhibitor and solvent contained in the composition B. Specifically, for the polysiloxane as the air diffusion inhibitor, the raw material organosilane, the molar ratio of the aryl group in R ^{1 to} the alkyl group in R ³ of the general formula (1), and the film thickness after drying are shown. . Other additives are also indicated. “Formation method” in the “Composition B” column indicates a formation method of the B layer using the composition B.

As described above, the method for manufacturing a semiconductor element and the method for manufacturing a solar cell according to the present invention are useful for reducing the number of manufacturing steps of the semiconductor element and the solar cell, and in particular, for a desired region in a semiconductor substrate. Suitable for highly efficient diffusion of impurity diffusion components.

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 A film 3 B layer 4 Impurity diffusion layer 11 Semiconductor substrate 12 A film 13 B layer 14 Impurity diffusion layer 15 Impurity diffusion composition film 16 Impurity diffusion layer 17 Passivation layers 18 and 19 Electrode 21 Semiconductor substrate 22 A film 23 B layer 24 Impurity diffusion layer 25 Impurity diffusion composition film 26 Impurity diffusion layer 27 Passivation layer 28, 29 Electrode 30 Impurity diffusion composition application substrate 31 Silicon wafer 32 A film 33 B layer 34 Impurity diffusion layer 40 Impurity diffusion composition application substrate 41, 51 Silicon wafer 45 Impurity diffusion composition film 46 Impurity diffusion layer 100, 200, 300 Semiconductor element 250, 350 Solar cell

Claims (15)

On the semiconductor substrate, an A film which is an impurity diffusion composition film using the composition A containing an impurity diffusion component and a composition B containing polysiloxane are used, and at least the impurities from the A film A film layer forming step of forming a B layer which is an air diffusion suppressing layer for suppressing air diffusion of a diffusion component;
A diffusion step of heat-treating the semiconductor substrate on which the A film and the B layer are formed to diffuse the impurity diffusion component in the semiconductor substrate;
The manufacturing method of the semiconductor element characterized by the above-mentioned. The film layer forming step includes
An A film forming step of forming the A film by applying the composition A on a predetermined surface of the semiconductor substrate;
A B layer forming step of forming the B layer by applying the composition B on the A film;
The manufacturing method of the semiconductor element of Claim 1 characterized by the above-mentioned. In the film layer forming step, a stacked body of the A film formed using the composition A in advance and the B layer formed using the composition B on the A film is formed on the semiconductor substrate. The method for manufacturing a semiconductor device according to claim 1, further comprising a step of laminating and forming on the surface. 4. The method of manufacturing a semiconductor element according to claim 1, wherein the thickness of the B layer after drying is 200 [nm] or more and 2000 [nm] or less. The method for producing a semiconductor element according to any one of claims 1 to 4, wherein the composition A contains a binder resin. 6. The method of manufacturing a semiconductor device according to claim 1, wherein the composition B contains a polysiloxane represented by the following general formula (1).

(In the general formula (1), R ¹ represents an aryl group having 6 to 15 carbon atoms, and a plurality of R ¹ may be the same or different. R ³ represents an alkyl group having 1 to 6 carbon atoms or a carbon number. an alkenyl group of 2 to 10, any good .R ² and R ⁴ be with or different multiple R ³ identical each a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 6 carbon atoms A plurality of R ² and R ⁴ may be the same or different from each other, provided that either one of R ² and R ⁴ is necessarily a hydroxyl group, and n and m are constituents of components in parentheses. N + m = 100, n: m = 90: 10 to 40:60, where X is a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, carbon An acyloxy group having 1 to 6 carbon atoms and an alkeni having 2 to 10 carbon atoms Any one of a group, an aryl group having 6 to 15 carbon atoms, and a heteroaryl group having 3 to 12 carbon atoms, Y is any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and an acyl group having 1 to 7 carbon atoms. ) 7. The method of manufacturing a semiconductor device according to claim 1, wherein the composition A and the composition B are compositions that are incompatible with each other. The composition A according to any one of claims 1 to 7, wherein the composition A contains a binder resin, and the decomposition temperature of the binder resin is lower than the curing temperature of the polysiloxane contained in the composition B. A method for manufacturing a semiconductor device. 9. The method of manufacturing a semiconductor device according to claim 1, wherein the film layer forming step continuously forms the A film and the B layer without going through a drying process by heat treatment. Method. 10. The method of manufacturing a semiconductor element according to claim 2, wherein the A film and the B layer are formed by a spin coating method. The method for manufacturing a semiconductor device according to claim 10, wherein the A film forming step and the B layer forming step are continuously performed without stopping rotation in the spin coating method. The composition A contains a water-soluble binder resin, the composition B contains a solvent, and the solubility of the water-soluble binder resin in the solvent is 0.01 [g / mL] or less at 25 ° C. The method of manufacturing a semiconductor device according to any one of claims 1 to 11, wherein: 13. The method for manufacturing a semiconductor device according to claim 1, wherein the composition A contains a boron compound, polyvinyl alcohol, and water. A film forming step of forming an impurity diffusion composition film having a conductivity type different from that of the A film on a surface of the semiconductor substrate opposite to the A film;
The diffusion step heat-treats the semiconductor substrate on which the impurity diffusion composition film, the A film, and the B layer are formed, and diffuses impurity diffusion components from the impurity diffusion composition film into the semiconductor substrate. And an impurity diffusion component from the A film is diffused into the semiconductor substrate, and an impurity diffusion layer from the impurity diffusion composition film and an impurity diffusion layer from the A film are simultaneously formed in the semiconductor substrate. The method for manufacturing a semiconductor device according to any one of claims 1 to 13, wherein: A method for manufacturing a solar cell, comprising the method for manufacturing a semiconductor element according to any one of claims 1 to 14.

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