WO2019188103A1 - Aminosilane compound, and composition for silicon-containing film formation containing said aminosilane compound - Google Patents

Abstract

Provided are an aminosilane compound that can decompose at a low temperature and a silicon-containing film production method that uses, as a silicon precursor, the aminosilane compound that can decompose at a low temperature. The foregoing are provided in order to, when forming a silicon-containing film, increase the film-forming rate through better adsorption on a substrate surface during film formation, and enable the film to be formed at a lower temperature by lowering the decomposition temperature.

Description

Aminosilane compound and composition for forming a silicon-containing film containing the aminosilane compound

The technical field of the present invention relates to a novel aminosilane compound and a composition for forming a silicon-containing film containing the compound.

In the manufacture of semiconductor devices, silicon-containing thin films are manufactured into various forms of thin films such as silicon films, silicon oxide films, silicon nitride films, silicon carbonitride films, and silicon oxynitride films by various deposition processes. It is applied in various fields. Among them, silicon oxide film and silicon nitride film have very good barrier properties and oxidation resistance, so insulating film, intermetallic dielectric material, seed layer, spacer, hard mask, trench isolation, diffusion prevention in device fabrication It functions as a film, an etching stopper layer, and a protective film layer.

In recent years, with the miniaturization of elements, the increase in aspect ratio, and the diversification of element materials, there is a demand for technology for forming ultrafine thin films with excellent electrical characteristics at low temperatures. In the conventional film forming method, it is necessary to set the film forming temperature to 600 ° C. or more, and there is a problem in that the step coverage, etching characteristics, and physical and electrical characteristics of the thin film are deteriorated.

In order to solve this problem, ammonia radicals (NH _3. ) Activated by plasma of dichlorosilane (DCS: SiH ₂ Cl ₂ ) and ammonia (NH ₃ ) are alternately supplied by atomic layer deposition (ALD). By reacting tetrachlorosilane (TCS: SiCl ₄ ) with water (H ₂ O) by a method of forming a silicon nitride film at a low temperature (300 ° C. to 600 ° C.) or ALD method, Thus, a method of forming a silicon oxide film at a low temperature (300 ° C. to 400 ° C.) (Patent Document 2) has been proposed.

JP 2004-281853 A JP 2005-11904 A

However, in the method of Patent Document 1, since the introduction of carbon into the silicon nitride film can cause a structural defect, there is a possibility that the insulation resistance is deteriorated. Further, the method of Patent Document 2 has a problem that TCS, which is a chloride, reacts with water to generate HCl, which corrodes exhaust system piping.

The present invention has been conceived under such circumstances, and does not contain carbon and halides. The formation of a silicon-containing film is achieved by improving the adsorptivity to the substrate surface during film formation. The main object is to provide a silicon precursor that enables film formation at a lower temperature by improving the film speed and lowering the decomposition temperature.

Conventionally, it has been common for reasons such as ease of synthesis to use an aminosilane compound in which the same amino group is bonded to a Si atom as a precursor for forming a silicon-containing film. As a result of intensive studies, it has been found that it is useful to use, as a silicon-containing film precursor, an aminosilane compound in which different amino groups are bonded to Si atoms in order to obtain a desired effect. Among these, by using an aminosilane compound in which two amino groups of a specific amino group that is a diisopropylamino group and a non-diisopropylamino group are bonded to a Si atom as a silicon-containing film precursor, It has been found that the film forming speed is improved by improving the adsorptivity to the substrate, and that the film can be formed at a lower temperature by lowering the decomposition temperature, and the present invention has been completed.

That is, this invention provides the invention of the aspect hung up below.
Item 1 The following formula:

（式中、Ｒ^１およびＲ^２はそれぞれ独立して、Ｈ、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基およびｔｅｒｔ－ブチル基からなる群から選択される置換基を表す。ただし、Ｒ^１およびＲ^２の両方がイソプロピル基である場合は含まれない。）
で表されるアミノシラン化合物。

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
An aminosilane compound represented by

Item 2: The following formula:

（式中、Ｒ^１およびＲ^２はそれぞれ独立して、Ｈ、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基およびｔｅｒｔ－ブチル基からなる群から選択される置換基を表す。ただし、Ｒ^１およびＲ^２の両方がイソプロピル基である場合は含まれない。）
で表される、シリコン含有膜形成用の前駆体。

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
A precursor for forming a silicon-containing film represented by:

Item 3. The precursor according to Item 2, wherein the silicon-containing film is formed by chemical vapor deposition.

Item 4. The precursor according to Item 3, wherein the chemical vapor deposition is atomic layer deposition.

Item 5 The following formula:

（式中、Ｒ^１およびＲ^２はそれぞれ独立して、Ｈ、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基およびｔｅｒｔ－ブチル基からなる群から選択される置換基を表す。ただし、Ｒ^１およびＲ^２の両方がイソプロピル基である場合は含まれない。）
で表されるアミノシラン化合物を含む、シリコン含有膜形成用の組成物。

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
The composition for silicon-containing film formation containing the aminosilane compound represented by these.

Item 6. The composition according to Item 5, wherein the silicon-containing film is formed by chemical vapor deposition.

Item 7. The composition according to Item 6, wherein the chemical vapor deposition is atomic layer deposition.

Item 8 The following formula:

（式中、Ｒ^１およびＲ^２はそれぞれ独立して、Ｈ、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基およびｔｅｒｔ－ブチル基からなる群から選択される置換基を表す。ただし、Ｒ^１およびＲ^２の両方がイソプロピル基である場合は含まれない。）
で表されるアミノシラン化合物の製造方法であって、
　　（ａ）ジクロロシランおよび第１のアミンを、溶媒に添加してアミノクロロシラン化合物を合成する合成工程；
　　（ｂ）副生塩を濾過により除去する濾過工程；
　　（ｃ）ろ液に第２のアミンを添加してアミノシラン化合物を合成する合成工程；および
　　（ｄ）蒸留によりアミノシラン化合物を単離する蒸留工程
を含む、製造方法。

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
A process for producing an aminosilane compound represented by
(A) a synthesis step of synthesizing an aminochlorosilane compound by adding dichlorosilane and a first amine to a solvent;
(B) a filtration step for removing by-product salts by filtration;
(C) A production process comprising a synthesis step of synthesizing an aminosilane compound by adding a second amine to the filtrate; and (d) a distillation step of isolating the aminosilane compound by distillation.

Item 9 The first amine in the synthesis step (a) is diisopropylamine, and the aminochlorosilane compound is represented by the following formula (1):

で表される中間体（１）であって、合成工程（ｃ）における第２のアミンが
　　Ｒ^１Ｒ^２ＮＨ
（式中、Ｒ^１およびＲ^２はそれぞれ独立して、Ｈ、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基およびｔｅｒｔ－ブチル基からなる群から選択される置換基を表す。ただし、Ｒ^１およびＲ^２の両方がイソプロピル基である場合は含まれない。）
で表されるＲ^１Ｒ^２ＮＨである、項８に記載の製造方法。

In which the second amine in the synthesis step (c) is R ¹ R ² NH
(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
Item 9. The production method according to Item 8, which is R ¹ R ² NH represented by:

Item 10 The first amine in the synthesis step (a) is R ¹ R ² NH
(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
And the aminochlorosilane compound is represented by the following formula (2):

（式中、Ｒ^１およびＲ^２はそれぞれ独立して、Ｈ、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基およびｔｅｒｔ－ブチル基からなる群から選択される置換基を表す。ただし、Ｒ^１およびＲ^２の両方がイソプロピル基である場合は含まれない。）
で表される中間体（２）であって、前記合成工程（ｃ）における第２のアミンがジイソプロピルアミンである、項８に記載の製造方法。

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
Item 9. The production method according to Item 8, wherein the second amine in the synthesis step (c) is diisopropylamine.

Item 11 The following formula:

（式中、Ｒ^１およびＲ^２はそれぞれ独立して、Ｈ、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基およびｔｅｒｔ－ブチル基からなる群から選択される置換基を表す。ただし、Ｒ^１およびＲ^２の両方がイソプロピル基である場合は含まれない。）
で表されるアミノシラン化合物を用いる、シリコン含有膜の製造方法。
項１２　シリコン含有膜は酸化シリコン膜である、項１１に記載のシリコン含有膜の製造方法。

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
The manufacturing method of a silicon-containing film | membrane using the aminosilane compound represented by these.
Item 12. The method for producing a silicon-containing film according to item 11, wherein the silicon-containing film is a silicon oxide film.

According to the present invention, by using a specific aminosilane compound as a silicon precursor, it becomes possible to form a film at a lower temperature without generating structural defects and corrosive gas. In addition, according to the method of the present invention, since the film formation rate is improved, a semiconductor device can be manufactured at lower cost and higher productivity.

^{1 is} a ¹ H-NMR chart of an aminosilane compound (diisopropylaminotertiarybutylaminosilane) obtained by the production method of the present invention. ^{1 is} a ¹ H-NMR chart of an aminosilane compound (diisopropylaminodimethylaminosilane) obtained by the production method of the present invention.

The present invention has the following formula:

（式中、Ｒ^１およびＲ^２はそれぞれ独立して、Ｈ、メチル基、エチル基、ｎ－プロピル基、イソプロピル（ｉ－Ｐｒ）基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基およびｔｅｒｔ－ブチル基からなる群から選択される置換基を表す。ただし、Ｒ^１およびＲ^２の両方がイソプロピル基である場合は含まれない。）
で表されるアミノシラン化合物を提供する。

Wherein R ¹ and R ² are each independently H, methyl group, ethyl group, n-propyl group, isopropyl (i-Pr) group, n-butyl group, sec-butyl group, isobutyl group and tert -Represents a substituent selected from the group consisting of butyl groups, except when both R ¹ and R ² are isopropyl groups.
The aminosilane compound represented by these is provided.

Preferred specific examples of NR ¹ R ² are NH (t-Bu) and N (CH ₃ ) ₂ .

The dipole moment of the aminosilane compound may be 0.85D or more, for example, 1.0D or more, and may be 2.0D or less, for example, 1.35D or less. Here, the dipole moment of the aminosilane compound means a vector amount from a negative charge to a positive charge derived from a partial charge on an atom in the molecule of the aminosilane compound. The dipole moment can be calculated by using a commercially available molecular chemistry calculation program. For example, it can be calculated by a density functional method (B3LYP / cc-pVDZ) using Gaussian 09 manufactured by Gaussian.

The method for producing an aminosilane compound according to the present invention includes (a) a synthesis step in which dichlorosilane and a first amine are added to a solvent to synthesize an aminochlorosilane compound, and (b) a filtration step in which by-product salts are removed by filtration. (C) a synthesis step of synthesizing an aminosilane compound by adding a second amine to the filtrate, and (d) a distillation step of isolating the aminosilane compound by distillation.

Examples of the solvent that can be used in the present invention include hydrocarbons such as hexane, cyclohexane, heptane, nonane, and decane; halogenated hydrocarbons such as dichloroethane, dichloromethane, and chloroform; benzene, toluene, xylene, chlorobenzene, trichlorobenzene, and the like. Aromatic hydrocarbons; and mixtures thereof. Among these, hydrocarbons such as hexane, cyclohexane, heptane, nonane and decane are preferable, and hexane is particularly preferable. The amount of solvent used is usually 0.1 to 50 times the mass of dichlorosilane.

In order to avoid hydrolysis of dichlorosilane, aminochlorosilane, and aminosilane, it is desirable that all reaction systems be conducted under anhydrous conditions, and moisture in all raw materials used is 0 to 5000 ppm by mass, preferably Reacts in the range of 0 to 400 ppm by mass. Further, it is desirable to use a reactor that has been dried by heating and drying, substituting with an inert gas such as nitrogen or argon.

In the step (a), the first amine is first dissolved in an organic solvent and dichlorosilane is added thereto, or the dichlorosilane is dissolved in an organic solvent and the first amine is added thereto. Any method can be applied to this reaction.

The amount of the first amine to be used is usually 1 to 4 times mol and preferably 1.5 to 2.5 times mol from the viewpoint of improving the yield with respect to dichlorosilane as a raw material.

Since the reaction is an exothermic reaction, the reaction temperature is preferably low. However, if the reaction temperature is too low, the yield may be reduced. Done. The reaction time is usually in the range of 0.5 to 10 hours.

In step (b), by-product salt is removed from the crude product in the reactor. In order to suppress the decomposition of aminochlorosilane, it is desirable to carry out under a dry inert gas, for example, under nitrogen or argon. The filtration temperature is not uniquely determined, but can be applied from 10 ° C. to the boiling point of the solvent used. It is preferable to carry out in the range of 20 to 65 ° C.

In step (c), the second amine is added dropwise to the filtrate obtained in step (b).

The amount of the second amine used is desirably 2 mol or more with respect to 1 mol of the total amount of the aminochlorosilane as an intermediate. Preferably there is.

Since the reaction is an exothermic reaction, it is preferred that the reaction is carried out at a low temperature. However, if the reaction temperature is too low, the yield may be reduced, so that the reaction is carried out in the range of -5 ° C to 60 ° C, preferably 0 to 50 ° C. Is called. The reaction time is usually in the range of 0.5 to 10 hours.

In step (d), the aminosilane compound is isolated by distillation, for example, vacuum distillation. The amine and the organic solvent are easily removed, and the aminosilane compound can be purified with sufficiently high purity.

In the production method of the first aspect of the present invention, first, by reacting dichlorosilane with diisopropylamine, the following formula (1):

で表される中間体（１）を製造し、中間体（１）に
　　Ｒ^１Ｒ^２ＮＨ
で表されるアミン化合物を反応させることにより製造する方法である。ここで、Ｒ^１およびＲ^２の具体的構造およびＮＲ^１Ｒ^２の好ましい例は、アミノシラン化合物の説明において上記で述べたとおりである。

An intermediate (1) represented by the formula (1) is produced, and R ¹ R ² NH is added to the intermediate (1).
It is the method of manufacturing by making the amine compound represented by these react. Here, specific structures of R ¹ and R ² and preferred examples of NR ¹ R ² are as described above in the description of the aminosilane compound.

The reaction formula of dichlorosilane and diisopropylamine ((i-Pr) ₂ NH) is shown below.

SiH ₂ Cl ₂ + 2 (i-Pr) ₂ NH → (i-Pr) ₂ NSiH ₂ Cl + (i-Pr) ₂ NH ・ HCl

The reaction formula of intermediate (1) and R ¹ R ² NH is shown below.

In the production method of the second aspect of the present invention, first, R ¹ R ² NH is reacted with dichlorosilane to form the following formula (2):

（式中、Ｒ^１およびＲ^２はそれぞれ独立して、Ｈ、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基およびｔｅｒｔ－ブチル基からなる群から選択される置換基を表す。ただし、Ｒ^１およびＲ^２の両方がイソプロピル基である場合は含まれない。）
で表される中間体（２）を製造し、中間体（２）にジイソプロピルアミンを反応させることにより製造する方法である。

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
Is produced by reacting diisopropylamine with the intermediate (2).

The reaction formula of dichlorosilane and R ¹ R ² NH is shown below.

SiH ₂ Cl ₂ + 2 R ¹ R ² NH → R ¹ R ² NSiH ₂ Cl + R ¹ R ² NH ・ HCl

The reaction formula of intermediate (2) and diisopropylamine is shown below.

Using the aminosilane compound according to the present invention as an intermediate of a silicon-containing film, a silicon-containing film such as a silicon nitride film or a silicon oxide film can be formed on a substrate. More specifically, the method for forming a silicon-containing film according to the present invention includes:
(E) On the substrate, the following formula:

（式中、Ｒ^１およびＲ^２はそれぞれ独立して、Ｈ、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基およびｔｅｒｔ－ブチル基からなる群から選択される置換基を表す。ただし、Ｒ^１およびＲ^２の両方がイソプロピル基である場合は含まれない。）
で表されるアミノシラン化合物を含むアミノシラン組成物を接触させて、基板に前記アミノシラン組成物を吸着させる工程；
　　（ｆ）未吸着のアミノシラン組成物および副生物をパージする工程；
　　（ｇ）前記アミノシラン組成物が吸着した基板に反応ガスを注入することで、アミノシランが分解され原子層を形成する工程；および
　　（ｈ）未反応の反応ガスと副生物をパージする工程
を含む、原子層堆積法である。

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
Contacting an aminosilane composition containing an aminosilane compound represented by formula (1) to adsorb the aminosilane composition on a substrate;
(F) purging unadsorbed aminosilane composition and by-products;
(G) injecting a reaction gas into the substrate on which the aminosilane composition has been adsorbed to decompose the aminosilane to form an atomic layer; and (h) purging unreacted reaction gas and by-products. Atomic layer deposition.

The substrate temperature (film formation temperature) may be 100 to 600 ° C., preferably 100 to 550 ° C. From the viewpoint of physical properties of the obtained film, energy saving, etc., the temperature of the substrate may be 550 ° C. or lower, for example, 450 ° C. or lower, preferably 400 ° C. or lower, more preferably 350 ° C. or lower, and further preferably Is 325 ° C. or lower. Further, the temperature of the substrate may be 100 ° C. or higher, for example, 150 ° C. or higher. The film formation temperature may be the temperature of at least one of steps (e) to (h), for example, the temperature of the substrate when contacting the aminosilane composition in step (e).

It is desirable to form the silicon-containing film after replacing with an inert gas such as nitrogen or argon. That is, the above step (e) may be performed after the inside of the reaction system is replaced with an inert gas.

The pressure at the time of injecting the aminosilane composition gas or the reaction gas in the step (e) may be 0.05 to 100 Torr, preferably 0.05 to 50 Torr. From the viewpoint of energy saving and the like, the supply time of the raw material aminosilane composition gas may be 10 seconds or less, for example, 5 seconds or less, preferably 3 seconds or less, more preferably 2 seconds or less.

The purge in the step (f) can be performed by introducing an inert gas such as argon. From the standpoint of energy saving and the like, the purge time in the step (f) may be 60 seconds or less, for example, 30 seconds or less, preferably 25 seconds or less.

The pressure at the time of injecting the aminosilane composition gas or reaction gas in the step (g) may be 0.05 to 100 Torr, and preferably 0.05 to 50 Torr. From the viewpoint of energy saving and the like, the supply time of the reaction gas may be 30 seconds or less, for example, 10 seconds or less, preferably 5 seconds or less.

In the step (g), at least one gas selected from nitrogen, ammonia, dinitrogen monoxide, nitrogen monoxide, and nitrogen dioxide is used as a reactive gas when forming a silicon nitride film having a Si—N bond. be able to. In forming a silicon oxide film having a Si—O bond, one or more gases selected from oxygen, ozone, and nitric oxide can be used.

The purge in step (h) can be performed by introducing an inert gas such as argon. From the viewpoint of energy saving and the like, the purge time in the step (f) may be 120 seconds or shorter, for example, 60 seconds or shorter, preferably 45 seconds or shorter.

The aminosilane compound in the present invention is suitably used for the production of a silicon-containing film (silicon oxide film, silicon nitride film, etc.) by the ALD method. In the method for producing a silicon-containing film in the present invention, the lower limit of the ALD window may be 300 ° C., preferably 275 ° C. In the method for producing a silicon-containing film according to the present invention, the upper limit of the ALD window may be 550 ° C., preferably 525 ° C. Here, the ALD window generally refers to a temperature range between the vaporization temperature of the silicon-containing film precursor compound and the thermal decomposition temperature of the silicon-containing film precursor compound. It can be defined as a temperature range from a point at which the deposition rate is maximized to a point at which the deposition rate is minimized when the film temperature is taken on the horizontal axis and the deposition rate is taken on the vertical axis.

Hereinafter, the present invention will be described in detail with reference to examples.

<Synthesis of aminosilane compound>
[Example 1: Synthesis of diisopropylamino tertiary butylaminosilane]
After nitrogen substitution, 101.2 g (1.0 mol) of diisopropylamine and 800 g of hexane were added to a 2000 mL flask equipped with a blowing tube, a thermometer, a cooling tube, and a motor stirrer. Cooled to ° C. When a gas of 50.5 g (0.5 mol) of dichlorosilane was introduced into the liquid at a rate of 50 mL per minute for 4 hours while being kept warm and stirred at 0 ° C., white smoke was produced and a white salt was produced. . After blowing dichlorosilane, the internal temperature of the flask was gradually warmed to room temperature over 3 hours and kept warm with stirring for 5 hours. Thereafter, the solid substance mainly containing amine hydrochloride as a by-product was removed by vacuum filtration in a nitrogen-substituted glove box to obtain a hexane solution containing diisopropylaminochlorosilane.

This diisopropylaminochlorosilane solution was added to a 2000 mL flask in which a thermometer, a condenser tube, and a motor agitator were set and purged with nitrogen, and was thrown into the refrigerant using acetone and cooled to 0 ° C. with a cooler. While keeping the temperature at 0 ° C. and stirring, 73.14 g (1.0 mol) of tertiary butylamine was slowly added dropwise over 2 hours. Thereafter, solids mainly composed of amine hydrochloride produced as a by-product were removed by filtration under reduced pressure in a nitrogen-substituted glove box to obtain a hexane solution containing diisopropylamino tertiary butylaminosilane.

The crude diisopropylamino tertiary butylaminosilane solution is subjected to atmospheric distillation at an internal temperature of 80 ° C to remove hexane from the crude diisopropylaminotertiarybutylaminosilane solution, and further distilled under reduced pressure at an internal temperature of 90 ° C and 10 Torr using a distillation tower. The final product was obtained with high purity.

GC analysis after distillation confirmed that 62.7 g (yield 62%) of an aminosilane compound was obtained with a purity of 99.6 area%. The obtained aminosilane compound was identified by ¹ H-NMR and GC-MS. The assignment of ¹ H-NMR is as follows.

σ (ppm) = 0.79 (( CH 3) 3 -C- NH -, 1H, s), 1.12 ([(CH 3) 2 -CH] 2 -N-, 12H, d, J = 7.0Hz), 1.19 (( CH ₃ ) ₃ -C-NH-, 9H, s), 3.27 ([(CH ₃ ) ₂ - CH ] ₂ -N-, 2H, sep), 4.57 ( -SiH _2- , 2H, d, J = 3.0Hz)

According to the results of ¹ H-NMR and GC-MS, the obtained aminosilane compound has the following formula:

で表されるジイソプロピルアミノターシャリーブチルアミノシランと同定した。

Was identified as diisopropylamino tertiary butylaminosilane.

[Example 2: Synthesis of diisopropylaminodimethylaminosilane]
After nitrogen substitution, 101.2 g (1.0 mol) of diisopropylamine and 800 g of hexane were added to a 2000 mL flask equipped with a blowing tube, a thermometer, a cooling tube, and a motor stirrer. Cooled to ° C. When a gas of 50.5 g (0.5 mol) of dichlorosilane was introduced into the liquid at a rate of 50 mL per minute for 4 hours while being kept warm and stirred at 0 ° C., white smoke was produced and a white salt was produced. . After blowing dichlorosilane, the internal temperature of the flask was gradually warmed to room temperature over 3 hours and kept warm with stirring for 5 hours. Thereafter, the solid substance mainly containing amine hydrochloride as a by-product was removed by vacuum filtration in a nitrogen-substituted glove box to obtain a hexane solution containing diisopropylaminochlorosilane.

This diisopropylaminochlorosilane solution was added to a 2000 mL flask in which a thermometer, a condenser tube, and a motor agitator were set and purged with nitrogen, and was thrown into the refrigerant using acetone and cooled to 0 ° C. with a cooler. While keeping the temperature at 0 ° C. and stirring, 45.08 g (1.0 mol) of dimethylamine was slowly blown in over 4 hours. Thereafter, solids mainly composed of amine hydrochloride by-produced by filtration under reduced pressure in a nitrogen-substituted glove box were removed to obtain a hexane solution containing diisopropylaminodimethylaminosilane.

The crude diisopropylaminodimethylaminosilane solution is distilled at atmospheric pressure at an internal temperature of 80 ° C. to remove hexane from the crude diisopropylaminodimethylaminosilane solution, and further distilled under reduced pressure at an internal temperature of 90 ° C. and 10 Torr using a distillation tower. The product was obtained with high purity.

GC analysis after distillation confirmed that 28.0 g (yield 32%) of an aminosilane compound was obtained with a purity of 96.1 area%. The obtained aminosilane compound was identified by ¹ H-NMR and GC-MS. The assignment of ¹ H-NMR is as follows.

σ (ppm) = 1.10 ([( CH ₃ ) ₂ -CH] ₂ -N-, 12H, d, J = 7.0Hz), 2.51 (( CH ₃ ) ₂ -N-, 6H, s), 3.18 ([ (CH ₃ ) ₂ - CH ] ₂ -N-, 2H, sep), 4.47 ( -SiH _2- , 2H, s)

According to the results of ¹ H-NMR and GC-MS, the obtained aminosilane compound has the following formula:

で表されるジイソプロピルアミノジメチルアミノシランと同定した。

It was identified as diisopropylaminodimethylaminosilane represented by

<Method for producing silicon-containing film>
[Example 3: Formation of silicon oxide film using diisopropylaminotertiarybutylaminosilane]
A silicon substrate was placed in a vacuum apparatus and heated to a predetermined temperature of 150 to 600 ° C. The aminosilane composition containing diisopropylaminotertiarybutylaminosilane obtained in Example 1 and a carrier gas was injected for a predetermined time of 1 to 6 seconds and adsorbed on a heated silicon substrate. Subsequently, argon gas was introduced into the apparatus for a predetermined time of 6 to 30 seconds to purge unadsorbed aminosilane composition and by-products. Thereafter, ozone was injected as a reaction gas at a pressure of 8 Torr for 3 seconds to form an atomic layer of silicon oxide derived from diisopropylamino tertiary butylaminosilane deposited on the substrate. Subsequently, unreacted ozone gas and by-products were purged by introducing argon gas for 30 seconds. The above cycle was repeated to obtain a silicon oxide film having a desired thickness.

[Example 4: Formation of silicon oxide film using diisopropylaminodimethylaminosilane]
A silicon substrate was placed in a vacuum apparatus and heated to a predetermined temperature of 150 to 600 ° C. The aminosilane composition containing diisopropylaminodimethylaminosilane and carrier gas obtained in Example 2 was injected for a predetermined time of 1 to 6 seconds and adsorbed on a heated silicon substrate. Subsequently, argon gas was introduced into the apparatus for a predetermined time of 6 to 30 seconds to purge unadsorbed aminosilane composition and by-products. Thereafter, ozone was injected as a reaction gas at a pressure of 8 Torr for 3 seconds to form an atomic layer of silicon oxide derived from diisopropylaminodimethylaminosilane deposited on the substrate. Subsequently, unreacted ozone gas and by-products were purged by introducing argon gas for 30 seconds. The above cycle was repeated to obtain a silicon oxide film having a desired thickness.

[Example 5: Formation of silicon nitride film using diisopropylaminotertiarybutylaminosilane]
A silicon substrate was placed in a vacuum apparatus and heated to a predetermined temperature of 100 to 600 ° C. The aminosilane composition containing diisopropylaminotertiarybutylaminosilane and carrier gas obtained in Example 1 was injected at a predetermined pressure of 0.05 to 100 Torr and adsorbed on a heated silicon substrate. The apparatus was then purged of unadsorbed aminosilane composition and by-products. Thereafter, ammonia was injected as a reaction gas at a pressure of 0.05 to 100 Torr to form an atomic layer of silicon nitride derived from diisopropylamino tertiary butylaminosilane deposited on the substrate. Next, unreacted ammonia gas and by-products were purged. The above cycle was repeated to obtain a silicon nitride film having a desired film thickness.

[Example 6: Formation of silicon nitride film using diisopropylaminodimethylaminosilane]
A silicon substrate was placed in a vacuum apparatus and heated to a predetermined temperature of 100 to 600 ° C. The aminosilane composition containing diisopropylaminodimethylaminosilane and carrier gas obtained in Example 2 was injected at a predetermined pressure of 0.05 to 100 Torr and adsorbed on a heated silicon substrate. The apparatus was then purged of unadsorbed aminosilane composition and by-products. Thereafter, ammonia as a reaction gas was injected at a pressure of 0.05 to 100 Torr to form an atomic layer of silicon nitride derived from diisopropylaminodimethylaminosilane deposited on the substrate. Next, unreacted ammonia gas and by-products were purged. The above cycle was repeated to obtain a silicon nitride film having a desired film thickness.

[Comparative Example 1: Formation of silicon-containing film using bisdiethylaminosilane]
Silicon-containing films were formed using bisdiethylaminosilane. A silicon substrate was placed in a vacuum apparatus and heated to a predetermined temperature of 150 to 600 ° C. An aminosilane composition containing bisdiethylaminosilane and a carrier gas was injected for a predetermined time of 1 to 6 seconds and adsorbed on a heated silicon substrate. Then, the unadsorbed aminosilane composition and by-products were purged into the apparatus by introducing argon gas for a predetermined time of 6 to 90 seconds. Thereafter, ozone was injected as a reaction gas for 3 seconds to form an atomic layer of silicon oxide derived from bisdiethylaminosilane deposited on the substrate. Subsequently, unreacted ozone gas and by-products were purged by introducing argon gas for 30 seconds. The above cycle was repeated to obtain a silicon oxide film having a desired thickness.

Table 1 shows specific vapor deposition methods, Table 2 shows the relationship between the raw material aminosilane supply time and the deposition rate at a substrate temperature of 300 ° C, and Table 3 shows the raw aminosilane purge time at a substrate temperature of 300 ° C. The relationship between the deposition rates is shown, and Table 4 shows the relationship between the substrate temperature and the deposition rate. The thickness of the formed layer was measured with an ellipsometer.

As shown in Table 2, the silicon oxide films manufactured in Example 3 and Example 4 both have a constant deposition rate in 1 second or more, whereas the silicon oxide film of Comparative Example 1 under the same conditions has 3 It was confirmed that the deposition rate became constant at a second or more, and in Examples 3 and 4, the time until the deposition rate became constant was shorter than that of Comparative Example 1.

As shown in Table 3, the silicon oxide films manufactured in Example 3 and Example 4 had a constant deposition rate when the argon purge time was 20 seconds or longer, whereas the silicon oxide film of Comparative Example 1 had an argon purge time. The deposition rate became constant after 60 seconds or more, and it was confirmed that Example 3 and Example 4 had a short time until the deposition rate became constant.

As shown in Table 4, the silicon oxide films manufactured in Examples 3 and 4 have a temperature range (ALD window) in which ALD film formation is possible, while the substrate temperature is 250 to 500 ° C. It was confirmed that the silicon oxide film of Example 1 was 300 to 550 ° C. Here, the ALD window was defined as the point from the maximum deposition rate to the minimum point.

That is, when a silicon oxide film is produced by the atomic layer deposition method using the aminosilane compound in the present invention, the material supply time and the purge time can be shortened, and the film formation temperature can be lowered. I understood.

By using the atomic deposition method, a silicon film such as a silicon nitride film or a silicon oxide film can be formed on a semiconductor substrate or nanowire having a high aspect ratio structure, which is extremely thin and free of atomic defects. . The aminosilane compound according to the present invention is useful for an atomic deposition method in which a film is formed at a lower temperature and in a shorter time.

Claims (12)

The following formula:

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
An aminosilane compound represented by The following formula:

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
A precursor for forming a silicon-containing film represented by: The precursor according to claim 2, wherein the silicon-containing film is formed by chemical vapor deposition. The precursor according to claim 3, wherein the chemical vapor deposition is atomic layer deposition. The following formula:

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
The composition for silicon-containing film formation containing the compound represented by these. The composition according to claim 5, wherein the silicon-containing film is formed by chemical vapor deposition. The composition according to claim 6, wherein the chemical vapor deposition is atomic layer deposition. The following formula:

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except that both R ¹ and R ² are isopropyl groups.)
A process for producing an aminosilane compound represented by
(A) a synthesis step of synthesizing an aminochlorosilane compound by adding dichlorosilane and a first amine to a solvent;
(B) a filtration step for removing by-product salts by filtration;
(C) A production process comprising a synthesis step of synthesizing an aminosilane compound by adding a second amine to the filtrate; and (d) a distillation step of isolating the aminosilane compound by distillation. In the synthesis step (a), the first amine is diisopropylamine, and the aminochlorosilane compound is represented by the following formula (1):

In which the second amine in the synthesis step (c) is R ¹ R ² NH
(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
In a ^R 1 ^R 2 NH, represented process of claim 8. The first amine in the synthesis step (a) is R ¹ R ² NH
(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
And the aminochlorosilane compound is represented by the following formula (2):

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
The production method according to claim 8, wherein the second amine in the synthesis step (c) is diisopropylamine. The following formula:

(Wherein R ¹ and R ² each independently comprise H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group) Represents a substituent selected from the group, except when both R ¹ and R ² are isopropyl groups.)
The manufacturing method of a silicon-containing film | membrane using the aminosilane compound represented by these. The method for producing a silicon-containing film according to claim 11, wherein the silicon-containing film is a silicon oxide film.

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