JP7039865B2 - Pattern forming method, uneven structure manufacturing method, replica mold manufacturing method, resist pattern reformer and pattern forming system - Google Patents

Description

The present disclosure relates to a pattern forming method, a method for manufacturing an uneven structure, a method for manufacturing a replica mold, a resist pattern modifying device, and a pattern forming system.

In recent years, in the manufacturing process of semiconductor devices (for example, semiconductor memory, etc.), a mold member (mold) having a fine concavo-convex structure formed on the surface of the substrate is used, and the fine concavo-convex structure is transferred to a workpiece such as a substrate. Nanoimprint technology, which is a pattern forming technology for transferring a fine concavo-convex structure at the same magnification, and photolithography technology using a photomask having a fine pattern are used.

Nanoimprint molds, photomasks, etc. having such a fine uneven structure or fine pattern generally have a fine uneven structure by exposing and developing a resist film provided on the surface of a substrate or a hard mask layer on the substrate. It is manufactured by forming a resist pattern corresponding to a fine pattern and then subjecting the substrate or hard mask layer on which the resist pattern is formed to an etching process using the resist pattern as a mask.

Similar to the nanoimprint mold and photomask, semiconductor devices such as semiconductor memory also transfer the fine concavo-convex structure of the nanoimprint mold to the resist film provided on the surface of the substrate, or to the resist film. A fine resist pattern is formed by exposure and development, and the substrate on which the resist pattern is formed is subjected to an etching process using the resist pattern as a mask to form a fine uneven structure on the substrate. It is manufactured through the process of.

In order to manufacture nanoimprint molds, photomasks, semiconductor devices, etc. that have fine uneven structures and fine patterns, it is necessary to form resist patterns with fine dimensions corresponding to the fine uneven structures and fine patterns on the substrate with high accuracy. There is.

The resist pattern is used as a mask for etching a substrate, a hard mask layer provided on the substrate, and the like. Therefore, in order to form fine uneven structures and fine patterns in nanoimprint molds, photomasks, semiconductor devices, etc. with high accuracy, the resist pattern is etched to the extent that it does not disappear during the etching process of the substrate or hard mask layer. It is required to be resistant.

From this point of view, conventionally, a method of transferring the resist pattern to a substrate with high accuracy by depositing a side wall protective material on at least the side wall of the resist pattern by ALD (atomic layer deposition) or the like has been proposed (patented). See Document 1).

Further, by alternately exposing the resist pattern formed by the electron beam lithography method and the photolithography method to a gas containing trimethylaluminum (TMA) and a gas containing _H2O , an organic resist having excellent resistance to plasma etching and milling is obtained. A method for forming a mask has been proposed (see Patent Document 2).

JP-A-2015-122497 U.S. Patent Publication 2012/0241411

In Patent Document 2 above, aluminum can be chemically reacted inside the resist pattern by alternately exposing the resist pattern to a gas containing trimethylaluminum (TMA) and a gas containing H ₂ O, and as a result, the resist pattern can be chemically reacted inside the resist pattern. It is described that the etching resistance of the resist pattern can be improved.

It is certain that alternating exposure of resist patterns to gas containing TMA and gas containing H ₂ O can improve etching resistance over the resist pattern before exposure to those gases. However, when the gas containing TMA and the gas containing _H2O are alternately exposed to the resist pattern, the degree of permeation (penetration concentration) of aluminum (TMA) in the resist pattern becomes distributed. For example, as shown in FIG. 10A, the vicinity of the surface of the resist pattern 320 is a layer with a relatively high aluminum concentration (high concentration layer) 321 and the inside thereof is a layer with a relatively low aluminum concentration (low concentration layer). ) 322. The base material 10'is etched using such a resist pattern 320 as a mask. The high-concentration layer 321 located at the top of the resist pattern 320 is easily etched, but the high-concentration layer 321 located on the side wall of the resist pattern 320 is difficult to be etched (see FIG. 10B). The low-concentration layer 322 is exposed from the top of the resist pattern 320, and the high-concentration layer 321 is located on the side wall. If the etching is proceeded as it is, the top of the resist pattern 320 is easily etched, but the side wall is difficult to be etched, so that the recess 323 is formed on the top of the resist pattern 320, and the resist pattern 320 is deformed (the resist pattern 320 is deformed). See FIG. 10 (C). Therefore, in the method described in Patent Document 2, when the base material 10'is etched using the resist pattern 320 deformed in this way as a mask, the deformed resist pattern 320 is transferred to the base material 10', and the concave portion 1b is formed on the top. There may be a problem that the concave-convex structure 1a'having'is formed on the base material 10'(see FIG. 10D).

In view of the above problems, the present invention improves the etching resistance and forms a concavo-convex structure with high accuracy by a method of forming a resist pattern that is not easily deformed in the subsequent etching step and an etching process using the resist pattern as a mask. It is an object of the present invention to provide a method for manufacturing a concavo-convex structure and a method for manufacturing a replica mold, as well as a resist pattern modifying apparatus and a pattern forming system.

In order to solve the above problems, as one embodiment of the present invention, a resist pattern having a plurality of convex portions and concave portions is formed on the first surface of a base material having a first surface and a second surface facing the first surface. By exposing the resist pattern to a first gas containing an inorganic element-containing compound exhibiting Lewis acidity under predetermined conditions, the atmosphere around the resist pattern is changed to the first gas atmosphere, and the inorganic is used. A first gas exposure step of chemically reacting an element-containing compound with a resist material constituting the resist pattern, and a first gas purging step of exhausting the first gas from the periphery of the resist pattern after the first gas exposure step. It has a second gas exposure step of exposing the resist pattern to a second gas containing an oxidizing agent under predetermined conditions, and in the first gas exposure step, the glass transition temperature of the resist material constituting the resist pattern. The resist pattern is exposed to the first gas under a temperature condition of less than, and after repeating a series of steps including the first gas exposure step and the first gas purging step a plurality of times, the second gas exposure step is performed at least. A one-time pattern forming method is provided.

In the second gas exposure step, the resist pattern may be exposed to the second gas under atmospheric pressure.

After the resist pattern forming step and before the first gas exposure step, adsorption for forming an adsorption prevention layer covering the surface of the convex portion of the resist pattern and the exposed surface on the first surface side exposed through the concave portion. Further having a preventive layer forming step, the adsorption preventive layer may be one that prevents the inorganic element-containing compound from adhering to the surface of the resist pattern, and in the resist pattern forming step, the convex portion. The resist pattern may be formed by performing an imprint process in a helium gas or a cohesive gas atmosphere using an imprint mold having recesses and protrusions corresponding to the recesses, an electron beam lithography method, or a photolithography method. The resist pattern may be formed by a lithography method, and a quartz glass substrate or a silicon substrate may be used as the substrate.

Further, as one embodiment of the present invention, a step of forming the pattern on the first surface of the base material by the pattern forming method and the first surface side of the base material using the pattern as a mask are used. Provided is a method for manufacturing a concavo-convex structure having a step of etching.

As one embodiment of the present invention, a step of forming the pattern on the hard mask layer of the base material on which the hard mask layer is formed on the first surface by the pattern forming method and masking the pattern. A method for manufacturing a concavo-convex structure, comprising a step of forming a hard mask pattern by etching the hard mask layer and a step of etching the first surface side of the base material using the hard mask pattern as a mask. Is provided.

As one embodiment of the present invention, there is a method of manufacturing a replica mold using the uneven structure manufactured by the method of manufacturing the concave-convex structure as a master mold, wherein the master mold and the first surface and facing the master mold are used. A transfer base material having a second surface to be transferred is prepared, the uneven pattern of the master mold is transferred to the transfer material on the first surface of the transfer base material, and the uneven pattern of the master mold is inverted. A replica mold comprising a step of forming an uneven pattern and a step of etching the first surface side of the transfer base material using the uneven pattern formed on the first surface of the transfer base material as a mask. Manufacturing method is provided.
A quartz glass substrate can be used as the transfer substrate.

As one embodiment of the present invention, a resist pattern modifying apparatus for modifying a resist pattern having a plurality of protrusions and recesses, wherein the resist pattern contains an inorganic element-containing compound exhibiting Lewis acidity. A gas exposure unit capable of exposing each of the gas and the second gas containing an oxidizing agent under predetermined conditions, a detection unit for detecting the modified state of the resist pattern due to exposure to the first gas, and the gas exposure unit. The control unit comprises a control unit for controlling the exposure of the first gas and the exposure of the second gas, and the control unit exposes the first gas to the resist pattern to the gas exposure unit. After repeating a series of processes including the process of changing the atmosphere around the resist pattern to the first gas atmosphere and the process of exhausting the first gas from the periphery of the resist pattern a plurality of times, the detection unit detects the resist pattern. Based on the result, there is provided a resist pattern reforming apparatus that causes the resist pattern to be exposed to the second gas once.

The detection unit can detect the modified state of the resist pattern by changing the optical characteristics of the resist pattern, and the change in the optical characteristics of the resist pattern includes a change in the refractive index with respect to a light beam having a predetermined wavelength. It may be a change in refractive index, a change in IR characteristics, or a change in color tone, or the detection unit may detect a modified state of the resist pattern by a change in the weight of the resist pattern.

The first treatment condition data regarding the exposure treatment of the first gas to the resist pattern by the gas exposure unit, the second treatment condition data regarding the exposure treatment of the second gas, and the reformed state data regarding the modified state of the resist pattern. The control unit further includes a storage unit that stores the gas in association with the gas, based on the first processing condition data, the second processing condition data, and the modified state data stored in the storage unit. The exposure of the first gas and the exposure of the second gas in the exposed portion may be controlled.

Even if the electron density data relating to the electron density of the organic material constituting the resist pattern is stored in the storage unit in association with the first processing condition data, the second processing condition data, and the modified state data. good.

As an embodiment of the present invention, there is provided a pattern forming system including the resist pattern reforming apparatus and a resist pattern forming apparatus for forming the resist pattern modified by the resist pattern modifying apparatus.

An etching apparatus for etching the member to be processed using the resist pattern modified by the resist pattern reforming apparatus as a mask can be further provided, and the resist pattern forming apparatus may be an imprint apparatus or an electron beam drawing apparatus. ..

As an embodiment of the present invention, there is provided a pattern forming system including the resist pattern reforming apparatus and an etching apparatus for etching a member to be machined using the resist pattern modified by the resist pattern modifying apparatus as a mask. Ru.

According to the present invention, there is a method of forming a resist pattern that is hard to be deformed in the subsequent etching step while improving the etching resistance, and a concave-convex structure capable of forming a concave-convex structure with high accuracy by an etching process using the resist pattern as a mask. It is possible to provide a method for manufacturing a body, a method for manufacturing a replica mold, and a resist pattern modifying device and a pattern forming system.

FIG. 1 is a flowchart showing each step of the pattern forming method according to the embodiment of the present invention. FIG. 2 is a process flow chart showing each step of a method for manufacturing a concavo-convex structure including a pattern forming method according to an embodiment of the present invention in a cut end view. FIG. 3 is a process flow chart showing the steps following FIG. 2 in a cut end view in each step of the method for manufacturing a concave-convex structure including the pattern forming method according to the embodiment of the present invention. FIG. 4 is a block diagram schematically showing a resist pattern reforming apparatus according to an embodiment of the present invention. FIG. 5 is a block diagram showing a schematic configuration of a resist pattern reforming apparatus according to an embodiment of the present invention. FIG. 6 is a block diagram showing a schematic configuration of a pattern forming system according to an embodiment of the present invention. FIG. 7 is a block diagram showing a schematic configuration of another aspect of the pattern forming system according to the embodiment of the present invention. FIG. 8 is a process flow chart showing another embodiment of a method of forming a resin uneven pattern having improved etching resistance in a cut end view. FIG. 9 is a graph showing the measurement results of the permeability of trimethylaluminum in Test Example 1. FIG. 10 is a process flow chart for explaining problems that may occur by the conventional pattern forming method and the method for manufacturing an uneven structure.

An embodiment of the present invention will be described with reference to the drawings.
In the drawings attached to the present specification, in order to facilitate understanding, the shape, scale, aspect ratio, etc. of each part may be changed or exaggerated from the actual product. The numerical range represented by using "-" in the present specification and the like means a range including each of the numerical values described before and after "-" as a lower limit value and an upper limit value. In the present specification and the like, terms such as "film", "sheet", and "board" are not distinguished from each other based on the difference in designation. For example, "board" is a concept that also includes members that may be commonly referred to as "sheets" or "films".

[Manufacturing method of uneven structure]
FIG. 1 is a flowchart showing each step of the pattern forming method according to the present embodiment, and FIGS. 2 and 3 are cut end faces of each step of the manufacturing method of the concave-convex structure including the pattern forming method according to the present embodiment. It is a process flow chart shown in the figure.

<Resist pattern forming process>
A base material 10 having a first surface 11 and a second surface 12 facing the first surface 11 is prepared, and a resin uneven pattern 31 is formed on the first surface 11 of the base material 10 (S01 in FIG. 1 and FIG. 2 (FIG. 2). A)-(C)).

The base material 10 includes, for example, quartz glass, soda glass, fluorite, calcium fluoride substrate, magnesium fluoride substrate, glass substrate such as acrylic glass, polycarbonate substrate, polypropylene substrate, resin substrate such as polyethylene substrate, and among these. A transparent substrate such as a laminated substrate formed by laminating two or more substrates arbitrarily selected from the above; a metal substrate such as a nickel substrate, a titanium substrate, or an aluminum substrate; a semiconductor substrate such as a silicon substrate or a gallium nitride substrate may be used. can.

In the present embodiment, a hard mask layer 20 made of metallic chromium, chromium oxide, chromium nitride, chromium oxynitride, or the like is provided on the first surface 11 of the base material 10. According to the pattern forming method according to the present embodiment, the uneven pattern 33 made of resin with improved etching resistance (see FIG. 3B) can be formed, so that the thickness of the hard mask layer 20, that is, the hard mask Even if the etching amount of the layer 20 is increased, the uneven pattern 32 does not disappear during the etching process. Therefore, in the present embodiment, the thickness of the hard mask layer 20 can be set to about 1 nm to 30 nm, preferably about 15 nm to 30 nm, whereby the uneven pattern formed on the first surface 11 of the base material 10 can be set. The aspect ratio of can be increased. It should be noted that the present embodiment is not limited to such an embodiment, and the hard mask layer 20 may not be provided.

The thickness of the base material 10 can be appropriately set in the range of, for example, about 300 μm to 10 mm in consideration of the strength of the substrate, handling suitability, and the like. In the present embodiment, "transparent" means that the transmittance of light rays having a wavelength of 300 nm to 450 nm is 85% or more, and is preferably 90% or more.

The resin material constituting the uneven pattern 31 made of resin is an inorganic element-containing compound contained in the first gas exposed to the uneven pattern 32 in the gas exposure step (first gas exposure step, S03 in FIG. 1) described later. It is not particularly limited as long as it has a reactive functional group exhibiting reactivity with. For example, a resin material having a reactive functional group such as a carbonyl group, a thiocarbonyl group, an acryloyl group, a hydroxyl group, a sulfanyl group, and an epoxy group can be used. Examples of such resin materials include imprint resins (ultraviolet curable resins such as acrylic and methacrylic) generally used for imprint processing using an imprint mold, electron beam lithography processing, and photolithography processing. An electron beam-sensitive resin, an ultraviolet-sensitive resin, and the like, which are generally used in the above, can be preferably used. In particular, the imprint resin tends to contain a large amount of reactive functional groups as compared with the resin for electron beam lithography and the resin for photolithography, so that the reaction can proceed efficiently.

The method for forming the uneven pattern 31 made of resin is not particularly limited, and for example, a photolithography method using a photomask having a predetermined opening and a light-shielding portion, and an electron beam using an electron beam drawing device. Examples thereof include a lithography method and an imprint method using an imprint mold having a predetermined uneven pattern, and the imprint method is particularly preferable from the viewpoint of mass productivity.

Here, a method of forming the uneven pattern 31 made of resin by the imprint method will be described.
First, the imprint mold 40 having the uneven structure 41 corresponding to the uneven pattern 31 made of resin is prepared, and the imprint resin film 30 is formed on the hard mask layer 20 of the base material 10 (see FIG. 2A). ).

Next, the uneven structure 41 of the imprint mold 40 is pressed against the imprint resin film 30, the uneven structure 41 is filled with the imprint resin, and the imprint resin film 30 is cured in that state (FIG. 2 (FIG. 2). B) See). As a method for curing the imprint resin film 30, a method corresponding to the curing type of the resin material constituting the imprint resin film 30 may be adopted. For example, if the resin material is an ultraviolet curable resin, the in-print resin film 30 may be cured. A method of irradiating the imprint resin film 30 with ultraviolet rays via the print mold 40 or the like can be adopted. When the concave-convex structure 41 of the imprint mold 40 is pressed against the imprint resin film 30, it is preferable to create a helium gas atmosphere or a cohesive gas atmosphere. A pattern defect (due to insufficient filling of the imprint resin) in the uneven pattern 31 due to the generation of air bubbles between the uneven structure 41 of the imprint mold 40 and the imprint resin filled in the uneven structure 41. (Pattern defects) may occur, but under a helium atmosphere or a cohesive gas atmosphere, the helium gas and cohesive gas constituting the bubbles can be dissolved in the imprint resin, and the occurrence of pattern defects can be prevented. can do.

The imprint mold 40 is pulled away from the cured imprint resin film 30 (see FIG. 2C). In this way, the resin uneven pattern 31 having the plurality of convex portions 31a, the concave portions 31b, and the residual film portion 31c located at the bottom of the concave portions 31b can be formed by the imprint method.

When the uneven pattern 31 made of resin is formed by an electron beam lithography method or a photolithography method, an electron beam sensitive resist material film or an ultraviolet sensitive resist material film is formed on the hard mask layer 20 of the base material 10. The resin-made uneven pattern 31 can be formed through a drawing process using an electron beam drawing device or the like, an exposure process using a photomask having a predetermined opening and a light-shielding portion, and a development process.

The shape of the uneven pattern 31 made of resin is not particularly limited, and examples thereof include a line-and-space shape, a hole shape, a pillar shape, and the like depending on the application. The size of the uneven pattern 31 made of resin may be any size according to the intended use, but if it is 10 nm or more and less than 30 nm (1X to 2X nm), particularly 10 nm or more and less than 20 nm (1X nm), the pattern formation according to the present embodiment. It is preferable because the effect of the method is noticeable. The aspect ratio of the uneven pattern 31 made of resin is not particularly limited, but is, for example, about 1 to 10. In the present embodiment, the etching resistance of the uneven pattern 32 made of resin, which can be used as an etching mask, is relatively improved through a gas exposure step (see S03 to S07 in FIG. 1 and FIG. 3A) described later. Even if the aspect ratio is small, the uneven pattern 32 does not disappear during the etching process, and the function as an etching mask can be sufficiently fulfilled.

<Remaining film removal process>
At the bottom of the concave portion 31b of the resin uneven pattern 31 formed by the imprint treatment, a residual film portion 31c having a predetermined thickness (about 1 nm to 20 nm, preferably about 5 nm to 10 nm) is present (FIG. 2 (FIG. 2). See C). It is desirable that the residual film portion 31c be removed before etching the hard mask layer 20. When the uneven pattern 31 having the residual film portion 31c is subjected to the gas exposure step described later (see S03 to S07 in FIG. 1 and FIG. 3A), the etching resistance of the residual film portion 31c is improved, and the residual film portion 31c is formed. It becomes difficult to remove. Therefore, before carrying out the gas exposure step (see S03 to S07 of FIG. 1 and FIG. 3A), the residual film portion 31c is removed (see FIG. 2D).

The method for removing the residual film portion 31c is not particularly limited, and examples thereof include ashing treatment with oxygen plasma, UV ozone treatment with ultraviolet light, VUV treatment with vacuum ultraviolet light, and the like.

Even in the uneven pattern made of resin formed by the electron beam lithography method or the photolithography method, a development residue may be present between the convex portions. Therefore, it is desirable to remove the development residue before carrying out the gas exposure step (see S03 in FIG. 1 and FIG. 3 (A)).

<Adsorption prevention layer forming process>
In the present embodiment, the uneven pattern 32 obtained by removing the residual film portion 31c as described above is exposed to the first gas and the second gas as described later, but prior to that, the uneven pattern 32 An adsorption prevention layer may be formed to cover the surface of the convex portion and the surface of the concave portion (the surface of the hard mask layer 20 exposed by removing the residual film portion 31c). The first gas that exposes the unevenness pattern 32 in the first gas exposure step described later contains an inorganic element-containing compound, and by exposing the first gas, the inorganic element-containing compound may be adsorbed on the surface of the unevenness pattern 32. When the inorganic element-containing compound is adsorbed on the surface of the uneven pattern 32, it becomes difficult for the inorganic element-containing compound to permeate the inside of the uneven pattern 32, and it becomes difficult to achieve the effect of improving the etching resistance. Further, if an inorganic element-containing compound is deposited on the surface of the concave portion of the uneven pattern 32 (the surface of the hard mask layer 20), or if the residual film portion 31c cannot be completely removed and the resin material remains in the concave portion, the concave portion is used. It becomes difficult to process (etch) the exposed hard mask layer 20. Therefore, by forming an adsorption prevention layer on the surface of the concavo-convex pattern 32 before carrying out the first gas exposure step, it is difficult for the inorganic element-containing compound to be adsorbed on the surface of the concavo-convex pattern 32, and it is easy to penetrate into the inside. In addition, the hard mask layer 20 can be easily processed (etched) using the uneven pattern 32 in which the inorganic element-containing compound has penetrated as a mask. Examples of the material constituting such an adsorption prevention layer include an alkylsilane coupling agent typified by a silane coupling agent (for example, hexyltrimethoxysilane, octadecyltriethoxysilane, etc.), a benzene ring, a silane having a benzophenone group, and the like. Coupling agent), hydrophobic polymer, carbon film such as graphene, etc., and the adsorption prevention layer is formed by, for example, a liquid phase method, a vapor phase method, a vapor deposition method such as CVD or ALD, a sputtering method, or the like. obtain. Before forming the resist pattern 31, the adsorption prevention layer may be formed in advance on the hard mask layer 20 of the base material 10.

<First processing condition and second processing condition setting process>
Next, the base material 10 having the uneven pattern 32 obtained by removing the residual film portion 31c is exposed to the first gas and the second gas (S03 to S07 in FIG. 1), but the first gas exposure step (FIG. The processing conditions (first processing conditions) of S03) of 1 and the processing conditions (second processing conditions) of the second gas exposure step (S06 of FIG. 1) are set (S02 of FIG. 1).

In the present embodiment, the first gas exposure step (S03 in FIG. 1) is repeated a plurality of times. Therefore, as the first treatment condition, the number of times the first gas exposure step is repeated, the treatment time of each first gas exposure step, and the like are set. In setting the first treatment condition, the resin material constituting the unevenness pattern 32 has been the target of the first gas exposure step in the past, and the first treatment condition has already been optimized. In that case, the condition may be set. However, when the resin material constituting the uneven pattern 32 has never been the target of the first gas exposure step, the information indicating the relationship between the information on the resin material and the first treatment condition is retained. If so, the first processing condition may be set based on the information. Examples of the information regarding the resin material include information regarding the electron density of the resin material. In the first gas exposure step (S03 in FIG. 1), as will be described later, the uneven pattern 32 is exposed to the first gas containing an inorganic element-containing compound exhibiting Lewis acidity. As a result, the inorganic element-containing compound permeates into the unevenness pattern 32 and reacts with the resin material constituting the unevenness pattern 32. The progress of this reaction is considered to depend on, for example, the type of the inorganic element-containing compound (for example, whether it is a nucleophilic compound or an electrophilic compound), the electron density of the resin material, and the like. Therefore, the first treatment condition considered to be suitable by comparing the electron density of the resin material for which the first treatment condition has already been optimized with the electron density of the resin material to be the target of the first gas exposure step for the first time. Can be set. The first treatment condition is the size of the uneven pattern 32, the type of the resin material constituting the uneven pattern 32, the type of the inorganic element-containing compound contained in the first gas, and the uneven pattern 32 having improved etching resistance as a mask. Conditions may be set in consideration of various conditions such as the type of the hard mask layer 20 to be etched and the type of material constituting the base material 10, and may be appropriately set.

Further, the second gas exposure step (S06 in FIG. 1) is carried out only once. Therefore, as the second treatment condition, the treatment time of the second gas exposure step and the like are set. This second processing condition can also be appropriately set from past experience and the like, similarly to the first processing condition described above.

<First gas exposure process>
According to the first treatment condition set as described above, the first gas exposure step is performed on the uneven pattern 32 (S03 in FIG. 1). Specifically, first, according to the first treatment condition, the atmosphere around the uneven pattern 32 contains an inorganic element-containing compound exhibiting Lewis acidity, and the carrier gas contains an inert gas such as nitrogen (N ₂ ). By creating an atmosphere of the first gas, the uneven pattern 32 made of resin is exposed to the first gas. By exposing the unevenness pattern 32 made of resin to the first gas according to the first treatment condition, the reactive functional groups and the inorganic element-containing compound in the chemical structure of the resin material constituting the unevenness pattern 32 are separated inside the unevenness pattern 32. Can be reacted.

Examples of the inorganic element-containing compound contained in the first gas include trimethylaluminum (Al (CH ₃ ) ₃ , TMA), methyltrichlorosilane, tris (dimethylamino) aluminum, tetrakis (diethylamino) titanium (IV), and titanium (IV). ) Isopropoxide, tetrachlorotitanium (IV), silicon tetrachloride, tris (t-pentoxy) silanol, bis (ethylmethylamino) silane can be exemplified. When the inorganic element-containing compound contained in the first gas is trimethylaluminum (TMA) and the reactive functional group is a carbonyl group, trimethylaluminum (TMA) and a carbonyl group are shown in the following reaction formula (1). Reacts with.

The first gas exposure step (S03 in FIG. 1) can be performed using, for example, a resist pattern reformer 50 (sequential vapor phase chemical reaction apparatus, see FIG. 4) described later. The first gas exposure step (S03 in FIG. 1) may be performed using an ALD (atomic layer deposition) device.

The first gas exposure step (S03 in FIG. 1) is carried out while monitoring the modified state of the unevenness pattern 32, that is, the progress of the reaction between the resin material constituting the unevenness pattern 32 and the inorganic element-containing compound. preferable. As the reaction between the resin material and the inorganic element-containing compound proceeds, for example, the optical characteristics of the unevenness pattern 32 change. Specifically, as the reaction between the resin material and the inorganic element-containing compound progresses, the reflectance, refractive index, IR characteristics, color tone, etc. for light rays having a predetermined wavelength change. Therefore, by monitoring the change in these optical characteristics, the progress of the reaction in the first gas exposure step can be confirmed and grasped, and the first gas exposure step may be controlled based on the result. Further, as the reaction between the resin material and the inorganic element-containing compound proceeds, for example, the weight of the uneven pattern 32 changes. Therefore, by monitoring the weight change of the uneven pattern 32, the progress of the reaction in the first gas exposure step can be confirmed and grasped, and the first gas exposure step may be controlled based on the result.

The time for exposing the resin uneven pattern 32 to the first gas (treatment time of each first gas exposure step) may be in accordance with the first treatment conditions set as described above, and is, for example, 30 seconds or more. The degree is preferably about 60 seconds to 1000 seconds. When the exposure time of the first gas is less than 30 seconds, the inorganic element-containing compound contained in the first gas binds to the reactive functional group located on the outermost surface of the uneven pattern 32 and chemically on the outermost surface of the uneven pattern 32. It is adsorbed and does not penetrate into the inside, and a thin film of inorganic oxide (so-called ALD film) is formed on the surface of the concave-convex pattern 32 due to the action of the oxidizing agent contained in the second gas described later, and the unevenness pattern 32 is etched. It may be difficult to improve resistance.

The temperature condition in the first gas exposure step (S03 in FIG. 1) may follow the first treatment condition set as described above, but is a temperature condition lower than the glass transition temperature of the resin material constituting the uneven pattern 32. Below, it is preferable to expose the uneven pattern 32 to the first gas. By exposing the uneven pattern 32 to the first gas while heating it, the reaction between the reactive functional group and the inorganic element-containing compound contained in the first gas can be promoted inside the uneven pattern 32. If the processing time of the gas exposure step is relatively long, the uneven pattern 32 may be deformed depending on the temperature conditions of the first gas exposure step. Therefore, by exposing the concavo-convex pattern 32 to the first gas under a temperature condition lower than the glass transition temperature of the resin material constituting the concavo-convex pattern 32, it is possible to prevent the concavo-convex pattern 32 made of resin from being deformed. can.

The processing pressure conditions in the first gas exposure step (S03 in FIG. 1) may be in accordance with the first processing conditions set as described above, and for example, 6.67 × 10 ⁴ Pa to 6.67 × 10 It is preferably set to about ⁵ Pa (50 Torr to 500 Torr), and more preferably set to about 1.33 × 10 ⁵ Pa to 4.00 × 10 ⁵ Pa (100 Torr to 300 Torr). When the treatment pressure condition is less than 6.67 × 10 ⁴ Pa (50 Torr), the inorganic element-containing compound contained in the first gas is contained, especially when the adsorption prevention layer is not formed on the surface of the uneven pattern 32. It binds to the reactive functional group located on the outermost surface of the uneven pattern 32 and is chemically adsorbed on the outermost surface of the uneven pattern 32 so that it does not easily penetrate into the inside. There is a risk that a thin film of inorganic oxide (so-called ALD film) will be formed on the surface of 32.

<First gas purging process>
Next, an inert gas such as nitrogen (N ₂ ) is supplied, and the surplus first gas is purged (exhausted) (S04 in FIG. 1). If the first gas is continuously exposed to the uneven pattern 32, the reaction between the reactive functional group and the inorganic element-containing compound becomes difficult to proceed over time. Therefore, the excess first gas is purged (exhausted) and the first gas is again exposed. By performing the exposure step (S03 in FIG. 1), the reaction between the reactive functional group and the inorganic element-containing compound can be efficiently promoted. In addition, the inorganic element-containing compound can be effectively permeated into the concave-convex pattern 32. The first gas purging step can be carried out, for example, for about 10 to 10000 seconds. This series of steps (S03 to S04 in FIG. 1) is regarded as one cycle, and a plurality of cycles are repeatedly carried out according to the first processing conditions. By repeating a series of steps (S03 to S04 in FIG. 1) of the first gas exposure step and the first gas purging step for a plurality of cycles, the inorganic element-containing compound is effectively permeated deep inside the uneven pattern 32, and the uneven pattern The chemical reaction can be efficiently performed inside the 32. Therefore, it is possible to obtain the same etching resistance on the surface and inside of the uneven pattern 32, and a concave portion is formed on the top of the uneven pattern 32 during the etching process of the hard mask layer 20 or the base material 10 using the uneven pattern 32 as a mask. It is possible to prevent it from being etched. As a result, the uneven pattern can be transferred to the base material 10 with high accuracy.

After the first gas purging step (S04 in FIG. 1) is completed, it is determined whether or not the number of repetitions of the first gas exposure step set as the first treatment condition has been reached (S05 in FIG. 1), and the number of repetitions is determined. (S05, No in FIG. 1), the first gas exposure step (S03 in FIG. 1) is carried out again. On the other hand, when the number of repetitions has been reached (S05, Yes in FIG. 1), the process proceeds to the second gas exposure step (S06 in FIG. 1).

<Second gas exposure process>
Subsequently, according to the second treatment condition, the uneven pattern 32 made of resin is exposed to the second gas containing an oxidizing agent (second gas exposure step, S06 in FIG. 1). By exposing the resin-made uneven pattern 32 repeatedly exposed to the first gas over a plurality of cycles to the second gas, the site of the inorganic element-containing compound bonded to the reactive functional group of the resin material constituting the uneven pattern 32 can be obtained. The remaining reactive active groups contained are hydrolyzed and replaced with hydroxyl groups. Since the dehydration condensation reaction occurs after that, the etching resistance of the uneven pattern 32 made of resin can be improved. The second gas exposure step is performed only once. The second gas exposure step may be repeated twice or more.

The oxidizing agent contained in the second gas may be any as long as it can replace the residual reactive active group contained in the moiety of the inorganic element-containing compound bonded to the reactive functional group with a hydroxyl group, for example, water ( Examples include H ₂ O), oxygen (O ₂ ), ozone, hydrogen peroxide and the like.

When the inorganic element-containing compound contained in the first gas is trimethylaluminum and the reactive functional group is a carbonyl group, it is contained in dimethylaluminum bonded to the carbonyl group as shown in the following reaction formula (2). The remaining reactive active groups (two methyl groups) are hydrolyzed with water as an oxidizing agent and replaced with hydroxyl groups. Then, as shown in the following reaction formula (3), a dehydration condensation reaction of the dihydroxyaluminum moiety occurs.

The time for exposing the resin uneven pattern 32 to the second gas (treatment time in the second gas exposure step) may be according to the second treatment condition, and is, for example, about 30 seconds to 1000 seconds, preferably 60 seconds to 500 seconds. It's about a second. When the treatment time of the second gas exposure step is less than 30 seconds, the hydrolysis reaction of the residual reaction active group contained in the site of the inorganic element-containing compound bonded to the reactive functional group inside the uneven pattern 32 is sufficiently performed. There is no risk.

In the second gas exposure step (S06 in FIG. 1), similarly to the first gas exposure step (S03 in FIG. 1), the temperature condition is equal to or lower than the melting point of the resin material constituting the uneven pattern 32, preferably lower than the glass transition temperature. Therefore, it is preferable to expose the uneven pattern 32 to the second gas. As a result, the uneven pattern 32 made of resin can be prevented from being softened and deformed, and the hydrolysis reaction of the residual reactive active group contained in the site of the inorganic element-containing compound bonded to the reactive functional group can be promoted. can.

The processing pressure condition in the second gas exposure step (S06 in FIG. 1) may be in accordance with the second processing condition, but is preferably set to atmospheric pressure, for example, 6.67 × 10 ⁴ Pa to 1.33. It is preferably set to about × 10 ⁶ Pa (50 Torr to 1000 Torr), and preferably about 5.33 × 10 ⁵ Pa to 9.87 × 10 ⁵ Pa (400 Torr to 740 Torr). If the second gas exposure step is carried out in a vacuum atmosphere, defects may occur in the uneven pattern 32, but when the second gas exposure step is carried out under atmospheric pressure, defects occur in the uneven pattern 32. Can be prevented from doing so.

<Second gas purging process>
Next, an inert gas such as nitrogen (N ₂ ) is supplied, and the surplus second gas is purged (exhausted) (S07 in FIG. 1). The second gas purging step (S07 in FIG. 1) may be carried out for, for example, about 30 to 1000 seconds, and the time for performing the second gas purging step is appropriately selected depending on the situation.

<Wet etching process>
By performing the first gas exposure step and the second gas exposure step (S03 to S07 in FIG. 1), the etching resistance of the resin uneven pattern 32 can be improved, but from between the convex portions 32a of the uneven pattern 32. A thin film derived from an inorganic element-containing compound (when TMA is used as the inorganic element-containing compound, a thin film of Al ₂ O ₃ , film thickness: about 0.1 nm to 10 nm) is formed on the exposed hard mask layer 20. .. If this thin film remains, the accuracy of the dimensions and the like of the hard mask pattern 21 deteriorates in the step of etching the hard mask layer 20 described later to form the hard mask pattern 21 (see FIG. 3C). There is a risk. Therefore, it is preferable to remove this thin film by wet etching.

The etching solution used in the wet etching step contains an acid capable of removing the thin film, and preferably an acid having a relatively strong oxidizing power for the material constituting the thin film (hypochlorous acid, chloric acid, etc.). It is a mixed acid solution containing a perchloric acid, nitric acid, sulfuric acid, peracetic acid, permanganic acid, dichromic acid, etc.) and a relatively weak acid (phosphate, acetic acid, phenol, etc.), and more preferably, the oxidizing power thereof is high. It is a mixed acid solution containing nitric acid as a relatively strong acid and phosphoric acid and acetic acid as relatively weak acids. The composition ratio (mass basis) of phosphoric acid, acetic acid and nitric acid in such a mixed acid solution is preferably 60 to 80: 1 to 20: 1 to 20, and preferably 65 to 75: 5 to 15: 1 to 5. Is particularly preferable. When the composition ratio of each acid in the mixed acid solution is within the above range, the thin film can be removed without damaging the uneven pattern 32 made of resin.

As a wet etching method, a method of immersing the base material 10 on which the unevenness pattern 32 made of the resin is formed in an etching solution, and a method of immersing the base material 10 on the surface (first surface 11) side of the base material 10 on which the unevenness pattern 32 is formed. Examples of a method of injecting an etching solution and the like can be exemplified, but the method is not limited thereto.

In the wet etching step, an etching treatment using a low-concentration etching solution (mixed acid solution content: 1 to 80% by mass) capable of removing the thin film formed between the convex portions 32a of the resin uneven pattern 32 is used. And / or it is preferable to perform the etching treatment for a short time (about 1 to 30 seconds) so that the thin film can be removed. As a result, the thin film can be removed without damaging the uneven pattern 32 made of resin.

<Hard mask pattern forming process>
Subsequently, the hard mask layer 20 is etched using the uneven pattern 32 subjected to the above-mentioned first gas exposure step and second gas exposure step (S03 to S07 in FIG. 1) and the wet etching step as a mask. The hard mask pattern 21 is formed (see FIG. 3C). In the present embodiment, since the etching resistance of the uneven pattern 32 made of resin is improved, it is possible to prevent the uneven pattern 32 from disappearing during the etching process of the hard mask layer 20. Therefore, the hard mask pattern 21 having extremely high dimensional accuracy is formed.

<Concave and convex structure forming process>
Using the hard mask pattern 21 thus formed as a mask, the first surface 11 side of the base material 10 is dry-etched to form the uneven structure 1a (see FIG. 3D), and finally the hard mask. By removing the pattern 21, the concavo-convex structure 1 having the concavo-convex structure 1a is manufactured (see FIG. 3E). Examples of the concavo-convex structure 1 manufactured in the present embodiment include an imprint mold, a photomask, and a semiconductor chip having a wiring pattern as the concavo-convex structure 1a.

[Manufacturing method of replica mold]
The imprint mold as the concave-convex structure 1 manufactured in the present embodiment can be used as a master mold for manufacturing a replica mold. The method for manufacturing the replica mold has a concavo-convex structure 1 as a master mold, a first surface and a second surface facing the first surface, and a hard mask layer (metal chrome, chromium oxide, chrome nitride, A process of preparing a base material for replica molding on which (made of chromium oxynitride, etc.) is formed, an imprint resin film (ultraviolet curable resin such as acrylic or methacrylic) on the hard mask layer of the base material for replica molding. In the process of forming a film (a film made of the like), the uneven structure 2 of the concave-convex structure 1 is transferred to the imprint resin film, and a concave-convex pattern obtained by inverting the concave-convex structure 1a of the concave-convex structure 1 is formed on the imprint resin film. The process, the process of etching the hard mask layer using the uneven pattern formed on the hard mask layer of the base material for replica molding as a mask to form the hard mask pattern, and the process of forming the hard mask pattern using the hard mask pattern as a mask, the first of the base material for replica molding. It includes a step of etching one surface side to form a concavo-convex structure in which the concavo-convex structure 1a of the concavo-convex structure 1 is inverted on the first surface of a substrate for replica molding.

Examples of the base material for the replica mold include quartz glass, soda glass, fluorite, calcium fluoride substrate, magnesium fluoride substrate, glass substrate such as acrylic glass, polycarbonate substrate, polypropylene substrate, resin substrate such as polyethylene substrate, and the like. A transparent substrate such as a laminated substrate obtained by laminating two or more substrates arbitrarily selected from the above can be used.

As described above, the concavo-convex structure 1 (master mold) manufactured in the present embodiment has the concavo-convex structure 1a formed with high accuracy. Therefore, a replica mold manufactured by using it as a master mold can also be manufactured as having a concavo-convex structure formed with high accuracy.

As described above, in the present embodiment, the resin uneven pattern 32 used as a mask when forming the hard mask pattern 21 by etching has extremely excellent etching resistance, and the resin uneven pattern 32 The hard mask pattern 21 is formed with high accuracy by removing the thin film formed on the hard mask layer 20 not covered with the above and then etching the hard mask layer 20 to form the hard mask pattern 21. .. Therefore, the uneven structure 1a is formed on the first surface 11 of the base material 10 with high accuracy by etching using the hard mask pattern 21 formed with high accuracy as an etching mask. Therefore, according to the present embodiment, it is possible to manufacture the concavo-convex structure 1 having the concavo-convex structure 1a formed with high accuracy.

[Resist pattern reformer]
Subsequently, a resist pattern reforming apparatus capable of carrying out the first gas exposure step and the second gas exposure step (S03 to S07 in FIG. 1) in the pattern forming method according to the present embodiment will be described. FIG. 4 is a schematic configuration diagram schematically showing the configuration of the resist pattern reformer according to the present embodiment.

As shown in FIG. 4, the resist pattern reforming apparatus 50 in the present embodiment has a chamber 51, a gas inlet 52 and a gas exhaust port 53, and an object to be treated (in the pattern forming method according to the present embodiment). A stage 54 on which a base material 10 (see FIG. 3A) on which a resin uneven pattern 32 is formed can be placed, and a heater capable of heating an object to be processed placed on the stage 54 (not shown). (Omitted) and a detection unit 55 located above the stage 54 and detecting the modified state of the resist pattern 32.

When the detection unit 55 exposes the first gas to the uneven pattern 32 formed on the base material 10 as the object to be treated, the detection unit 55 has optical characteristics (for example, reflectance, refractive index, IR) of the uneven pattern 32. It may be composed of an optical sensor, a weight sensor, or the like that can monitor changes in characteristics, color tone, etc.) and weight over time. When the detection unit 55 is composed of a weight sensor, the detection unit 55 may be built in the stage 54.

In the resist pattern reforming apparatus 50, when the first gas is supplied into the chamber 51 from the gas inlet 52, the first gas flows toward the gas exhaust port 53, so that the object to be processed located between them ( The circumference of the uneven pattern 32) can be made into a first gas atmosphere. As a result, the inorganic element-containing compound contained in the first gas can be infiltrated into the concavo-convex pattern 32, and the reactive functional group of the resin material can be reacted with the inorganic element-containing compound.

As shown in FIG. 5, the resist pattern reforming device 50 in the present embodiment is a communication unit 63 for transmitting and receiving data and the like between the control unit 61, the storage unit 62, and the resist pattern reforming device 50. Further includes a control device 60 having the above. The control unit 61 is based on various information stored in the storage unit 62, information input from the user, and the like, and data related to the first processing condition (for example, the number of times the first gas exposure step is repeated, each time). Data on the processing time of the first gas exposure process, etc.) and data on the second processing conditions (for example, data on the processing time, etc. of the second gas exposure process) can be generated, and the registration pattern can be modified based on those data. Arithmetic processing for controlling the first gas exposure step (S03 in FIG. 1), the second gas exposure step (S06 in FIG. 1), and the like in the quality apparatus 50 is performed.

The storage unit 62 temporarily stores information input from the user, a program for the control unit 61 to perform various arithmetic processes, data related to the first processing condition generated by the control unit 61, and a second. Data on processing conditions, monitoring information obtained by monitoring by the detection unit 55 (for example, information on changes in optical characteristics and weight of the uneven pattern 32), information on various resin materials that can form the uneven pattern 32 (for example). , Information on the type of resin material, electron density of the resin material, etc.), etc. are stored.

The data regarding the first processing condition and the data regarding the second processing condition stored in the storage unit 62 are the data when the first gas exposure step and the second gas exposure step were performed in the past by the resist pattern reformer 50. It is the data about the first processing condition and the second processing condition, and is associated with the information about the resin material constituting the unevenness pattern 32 at that time. Further, the data regarding the first treatment condition and the second treatment condition are obtained by being monitored by the detection unit 55 when the first gas exposure step and the second gas exposure step have been performed in the past by the resist pattern reformer 50. It may be updated based on the monitoring information provided.

When the resist pattern reforming apparatus 50 in the present embodiment performs the resist pattern reforming process, the control unit 61 generates data related to the first processing condition and data related to the second processing condition according to the information input from the user and the like. do. For example, when information regarding the type of the resin material constituting the unevenness pattern 32 is input, the data regarding the first processing condition and the data regarding the second processing condition associated with the resin material are stored in the storage unit 62. In that case, the data relating to the first processing condition and the data relating to the second processing condition are read out. On the other hand, when the data regarding the first processing condition and the data regarding the second processing condition associated with the resin material are not stored in the storage unit 62, the first is based on the information on the electron density of the resin material. Generate data related to the processing condition and data related to the second processing condition. For example, the electron density of the new resin material is obtained from the information regarding the type of the resin material input by the user. Then, in comparison with the electron density of the resin material associated with the data regarding the first treatment condition and the data regarding the second treatment condition, the data regarding the first treatment condition and the second treatment condition associated with the resin material having the closest electron density are obtained. Based on the data regarding the processing conditions, the data regarding the first processing conditions and the data regarding the second processing conditions for the uneven pattern 32 made of the new resin material are generated.

The control unit 61 controls the processing in the resist pattern reforming apparatus 50 based on the data regarding the first processing condition and the data regarding the second processing condition generated as described above, and the resist pattern reforming apparatus 50 controls the processing. A series of steps of the first gas exposure step and the first gas purge step are repeated a plurality of times. At this time, the detection unit 55 monitors changes in the optical characteristics and weight of the uneven pattern 32 over time, and the monitoring information output from the detection unit 55 is stored in the storage unit 62. After the series of steps of the first gas exposure step and the first gas purge step is completed, the series of steps of the second gas exposure step and the second gas purge step are carried out, and the reforming process for the uneven pattern 32 is completed.

After the series of steps of the first gas exposure step and the first gas purge step is completed, the control unit 61 has a series of steps of the second gas exposure step and the second gas purge step based on the monitoring information output from the detection unit 55. You may decide whether or not to carry out. For example, the first gas exposure step of the number of repetitions in the data regarding the first treatment condition generated at the start of the treatment in the resist pattern reformer 50 is completed, but the resin material and the inorganic element constituting the uneven pattern 32 are based on the monitoring information. If it is determined that the reaction with the contained compound is insufficient, the first gas exposure step may be carried out again without shifting to the second gas exposure step. By performing such control, the optimum reforming process of the unevenness pattern 32 can be performed.

Further, the control unit 61 feeds back the monitoring information output from the detection unit 55 to the data related to the first processing condition first generated, and the number of repetitions of a series of steps of the first gas exposure step and the first gas purge step. Etc. may be changed during the processing in the resist pattern reformer 50. By providing such a feedback function, the unevenness pattern 32 can be modified under the optimum processing conditions.

[Pattern formation system]
Subsequently, the pattern forming system in this embodiment will be described. 6 and 7 are block diagrams showing a schematic configuration of the pattern forming system according to the present embodiment.

As shown in FIG. 6, the pattern forming system 100 in the present embodiment includes a pattern forming device 70, the resist pattern modifying device 50, and a base material processing device 90. Further, as shown in FIG. 7, the pattern forming system 100 in the present embodiment may further include a developing device 80.

The pattern forming apparatus 70 is an apparatus for forming a resin uneven pattern 32 modified by the resist pattern modifying apparatus 50 on the first surface 11 of the base material 10, for example, a nanoimprint apparatus and an electron beam. It is composed of a drawing device and the like.

The base material processing device 90 can form the uneven structure 1a on the first surface 11 of the base material 10 by using the resin uneven pattern 32 modified by the resist pattern modifying device 50 as a mask, or can be used in the pattern forming device 70. This is an apparatus for removing the residual film portion 31C remaining between the concave portions 31b of the concave-convex pattern 31 formed therein, and is configured by, for example, an etching apparatus or the like.

Between the pattern forming device 70 and the resist pattern reforming device 50, and between the resist pattern reforming device 50 and the base material processing device 90, a transport device for transporting the base material 10 on which the uneven pattern 32 is formed is provided. It will be provided. The transfer device has a configuration in which the base material 10 carried out from the pattern forming device 70 (resist pattern reforming device 50) is carried into the resist pattern reforming device 50 (base material processing device 90) via a conveyor. The base material 10 carried out from the pattern forming apparatus 70 (resist pattern reforming apparatus 50) may be carried into the resist pattern reforming apparatus 50 (resist pattern processing apparatus 90) by a robot transfer apparatus. It may have a configuration.

When the pressure in each chamber of the pattern forming apparatus 70 and the resist pattern reforming apparatus 50 is different, or when the pressure in each chamber of the resist pattern reforming apparatus 50 and the substrate processing apparatus 90 is different, the substrate 10 is used. The pressure atmosphere around the substrate 10 to be conveyed may be adjusted so that the fluctuation of the pressure applied to the uneven pattern 32 on the substrate 10 becomes gentle in the process of the transfer.

As shown in FIG. 7, the pattern forming system 100 in the present embodiment may further include a developing device 80. A thin film of an oxide (for example, Al ₂ O ₃ ) of an inorganic element-containing compound derived from the first gas is formed on the first surface 11 of the base material 10 treated by the resist pattern reformer 50. .. Further, the uneven pattern 32 used as a mask remains on the first surface 11 of the base material 10 processed by the base material processing apparatus 90. The developing device 80 can serve as a cleaning device for peeling off these thin films and the remaining uneven pattern 32.

The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

In the above embodiment, an embodiment in which a resin uneven pattern 31 (32) is formed on the hard mask layer 20 of the base material 10 on which the hard mask layer 20 is formed on the first surface 11 will be described as an example. However, the present invention is not limited to such an embodiment. For example, a resin uneven pattern 31 (32) may be formed on the first surface 11 of the base material 10 having no hard mask layer 20. Generally, as the resin material constituting the unevenness pattern 31 (32), there are many materials having a small difference in etching rate with the material constituting the base material 10, and the unevenness pattern made of resin which does not improve the etching resistance is used. When the base material 10 is etched as a mask, there is a problem that the uneven pattern disappears during the etching process of the base material 10, and even if the uneven pattern does not completely disappear, the shoulder portion of the uneven pattern is etched and the base material 10 is etched. There arises a problem that the dimensional accuracy of the concave-convex structure 2 formed on the first surface 11 is lowered. However, since the uneven pattern 32 formed in the above embodiment has extremely excellent etching resistance, the uneven structure 2 having good dimensional accuracy can be obtained by etching the base material 10 using the uneven pattern 32 as a mask. It can be formed on the first surface 11 of 10. In such an embodiment, in order to remove the uneven pattern 32 from the first surface 11 side of the base material 10 on which the uneven structure 2 is formed, the etching solution containing the mixed acid solution described above is composed of acetone, toluene and the like. It is desirable to apply a wet etching treatment using an etching solution to the base material 10.

In the above embodiment, the hard mask layer 20 is formed on the first surface 11 of the base material 10, the uneven pattern 31 (32) made of resin is formed on the hard mask layer 20, and the uneven pattern 32 is the first. Although the embodiment of exposing the 1st gas and the 2nd gas has been described as an example, the present invention is not limited to such an embodiment. For example, as shown in FIG. 8, a positive electron beam-sensitive or ultraviolet-sensitive resist material film 30'is formed on the hard mask layer 20, and the resist material film 30' is exposed to an electron beam or ultraviolet rays. After forming a latent image (exposed portion 32'and unexposed portion 33') of the uneven pattern 32 and performing a gas exposure step on the exposed portion 32'and the unexposed portion 33' exposed to electron beams or ultraviolet rays. The uneven pattern 32 may be formed by removing the unexposed portion 33'in a dry process, for example, by performing a dry etching process. In the positive type resist material, the solubility of the exposed portion 32'exposed to the electron beam or ultraviolet rays in the developing solution is increased, but the resist material film 30 is exposed in a pattern and a latent image of the uneven pattern 32 is formed. When the gas exposure step is carried out on', the etching resistance (dry etching resistance) of the exposed portion 32'is improved more than the etching resistance of the unexposed portion 33'. It is considered that this is because the permeability of the inorganic element-containing compound to the exposed portion 32'is higher than the permeability of the inorganic element-containing compound to the unexposed portion 33'. Therefore, by performing the gas exposure step on the resist material film 30'in which the latent image of the uneven pattern 32 is formed, the exposed portion 32'with improved etching resistance is used as the uneven pattern 32 as the base material 10 (hard mask layer 20). ) Can be left on. That is, a resin uneven pattern that can be formed by an electron beam lithography method or a photolithography method using a negative resist material can be produced by using a positive resist material. Further, in a general electron beam lithography method or photolithography method, a developing process using a developing solution is required, and the surface tension of the developing solution or the like may cause the uneven pattern made of resin to collapse. However, according to the above method, since the resin uneven pattern can be formed without the need for development processing using a developer, the resin uneven pattern collapses due to the surface tension of the developer or the like. Can be prevented.

In the above embodiment, the pattern forming system 100 includes a pattern forming device 70, a resist pattern modifying device 50, a base material processing device 90, and if desired, a developing device 80, but is limited to this embodiment. It's not something. For example, the pattern forming system 100 may include a resist pattern modifying device 50 and a pattern forming device 70 or a base material processing device 90. Further, the transport device included in the pattern forming system 100 may be provided between the pattern forming device 70 and the etching device 90.

Hereinafter, the present invention will be described in more detail with reference to examples and the like, but the present invention is not limited to the following examples and the like.

[Test Example 1]
An electron beam resist (PMMA, manufactured by Aldrich) having a carbonyl group as a reactive functional group was applied on one surface of a silicon wafer by spin coating to form a resist film. The silicon wafer on which the resist film was formed was set in the chamber of an ALD apparatus (manufactured by Ultratech, product name: Savannah S200), and the first gas exposure step (S03 in FIG. 1) was carried out.

In the gas exposure step, first, a first gas containing trimethylaluminum (TMA) was supplied into the chamber under the following conditions.
Carrier gas: Nitrogen (N ₂ )
Processing pressure condition: 466.6 Pa (3.5 Torr)
Processing time: 60 seconds

Next, nitrogen (N ₂ ) was supplied into the chamber for 30 seconds to purge the first gas remaining in the chamber. After performing this series of steps (first gas exposure step and first gas purge step) for 200 cycles, the second gas (H ₂ O) was supplied into the chamber under the following conditions (second gas exposure step, FIG. 1 S06).
Processing pressure condition: 933.2 Pa (7.0 Torr)
Processing time: 500 seconds

Finally, nitrogen (N ₂ ) was supplied into the chamber for 30 seconds to purge the second gas remaining in the chamber (second gas purging step, S07 in FIG. 1). The permeability of trimethylaluminum in the resist film subjected to the gas exposure step as described above was measured using an atomic resolution analysis electron microscope (TEM-EDX, product name: JEM-ARM200F, manufactured by JEOL Ltd.). The results are shown in FIG.

For comparison, a series of steps of the first gas exposure step, the first gas purge step, the second gas exposure step, and the second gas purge step are performed on the resist membrane for three cycles to determine the permeability of trimethylaluminum in the resist membrane. , Measured in the same manner as above. The results are also shown in FIG.

FIG. 9 is a graph showing the permeability of trimethylaluminum in the thickness direction of the resist film, in which the horizontal axis represents the film thickness from the upper surface of the resist film and the vertical axis represents the number of aluminum atoms. The plot indicated by “▲” in FIG. 9 shows the aluminum atoms in the resist film in which the first gas exposure step and the first gas purge step are repeatedly carried out for 200 cycles, and then the second gas exposure step and the second gas purge step are carried out for one cycle. Represents the number of. The plot indicated by “◯” represents the number of aluminum atoms in the resist film obtained by performing a series of steps of the first gas exposure step, the first gas purge step, the second gas purge step, and the second gas purge step for three cycles. There is. From the results shown in FIG. 9, in the former resist film (after performing a series of steps of the first gas exposure step and the first gas purge step a plurality of times, the second gas exposure step and the second gas purge step are carried out once). Compared to the latter (a series of steps of the first gas exposure step, the first gas purge step, the second gas purge step and the second gas purge step is carried out a plurality of times), trimethylaluminum is effectively permeated in the thickness direction. It was confirmed that it could be done.

[Example 1]
An electron beam resist (PMMA, manufactured by Aldrich) having a carbonyl group as a reactive functional group was applied by spin coating on one surface (first surface) of a silicon wafer to form a resist film. A pattern latent image was formed on the resist film using an electron beam drawing apparatus, and a development process was performed to form a line-and-space-shaped uneven pattern 32 (half pitch: 32 nm, height: 30 nm). The silicon wafer on which the uneven pattern 32 is formed is set in the chamber of the ALD apparatus (manufactured by Ultratech, product name: Savannah S200), and the first gas exposure step (S03 in FIG. 1) is performed in the same manner as in Test Example 1. Carried out.

Next, nitrogen (N ₂ ) was supplied into the chamber for 30 seconds to purge the first gas remaining in the chamber. After performing this series of steps (first gas exposure step and first gas purging step) for 10 cycles, the second gas ( _H2O ) was supplied into the chamber in the same manner as in Test Example 1 (S06 in FIG. 1). ..

Finally, nitrogen (N ₂ ) was supplied into the chamber for 30 seconds to purge the second gas remaining in the chamber (S07 in FIG. 1). Then, using the uneven pattern 32 as a mask, a dry etching process was performed on the first surface of the silicon wafer to form an uneven pattern on the first surface of the silicon wafer. When the uneven pattern formed on the first surface of the silicon wafer was observed using an electron microscope, it was confirmed that the uneven pattern 32 was transferred with high accuracy.

[Example 2]
An uneven pattern was formed on the first surface of the silicon wafer in the same manner as in Example 1 except that a series of steps (first gas exposure step and first gas purging step) were carried out for 100 cycles. When the uneven pattern formed on the first surface of the silicon wafer was observed using an electron microscope, it was confirmed that the uneven pattern 32 was transferred with high accuracy.

[Comparative Example 1]
The silicon wafer first is the same as in Example 1 except that the gas exposure step (a series of steps of the first gas exposure step and the first gas purge step, and the second gas exposure step and the second gas purge step) is not carried out. An uneven pattern was formed on one surface. When the uneven pattern formed on the first surface of the silicon wafer was observed using an electron microscope, although the uneven pattern made of resin was transferred, the silicon wafer was the first in comparison with Examples 1 and 2. It was confirmed that the height of the uneven pattern formed on one surface was low. It is presumed that the cause was insufficient etching resistance of the uneven pattern made of resin.

[Comparative Example 2]
The first surface of the silicon wafer is uneven in the same manner as in Example 1 except that a series of steps of the first gas exposure step, the first gas purge step, the second gas purge step, and the second gas purge step are carried out for five cycles. Formed a pattern. When the uneven pattern formed on the first surface of the silicon wafer was observed using an electron microscope, a concave portion was formed on the top of the uneven pattern. In Comparative Example 2, it is said that the fact that trimethylaluminum did not effectively penetrate into the unevenness pattern made of resin was the reason why the concave portion was formed on the top of the unevenness pattern formed on the first surface of the silicon wafer. Inferred.

[Test Example 2]
A positive electron beam resist (ZEP520A, manufactured by Zeon Corporation) having a carbonyl group as a reactive functional group was applied on one surface (first surface) of a silicon wafer by spin coating to form a resist film. A pattern latent image (exposed part and unexposed part) was formed on the resist film by using an electron beam drawing apparatus. For the resist film on which the pattern latent image was formed, the gas exposure step (a series of steps of the first gas exposure step and the first gas purge step was performed for 200 cycles, the second gas exposure step and the second gas purge) in the same manner as in Test Example 1. The process was carried out for one cycle). Then, the first surface of the silicon wafer was subjected to a dry etching process. As a result, the unexposed portion was removed by the dry etching process, and the exposed portion could remain as an uneven pattern on the first surface of the silicon wafer.

The present invention is useful as a method for forming a resin uneven pattern used as an etching mask in the manufacturing process of a semiconductor device or the like.

1 ... Concavo-convex structure 10 ... Base material 11 ... First surface 12 ... Second surface 20 ... Hard mask layer 21 ... Hard mask pattern 31 ... Concavo-convex pattern 31a ... Convex portion 31b ... Concave 31c ... Remaining film portion 32 ... Concavo-convex pattern

Claims (21)

A resist pattern forming step of forming a resist pattern having a plurality of convex portions and concave portions on the first surface of a base material having a first surface and a second surface facing the first surface.
By exposing the resist pattern to a first gas containing an inorganic element-containing compound exhibiting Lewis acidity under predetermined conditions, the atmosphere around the resist pattern is changed to the first gas atmosphere, and the inorganic element-containing compound and the resist pattern are made. The first gas exposure step of chemically reacting with the resist material constituting the
After the first gas exposure step, a first gas purging step of exhausting the first gas from the periphery of the resist pattern and a first gas purging step.
It has a second gas exposure step of exposing the resist pattern to a second gas containing an oxidizing agent under predetermined conditions.
In the first gas exposure step, the resist pattern is exposed to the first gas under a temperature condition lower than the glass transition temperature of the resist material constituting the resist pattern.
A pattern forming method in which a series of steps including the first gas exposure step and the first gas purging step is repeated a plurality of times, and then the second gas exposure step is performed at least once. The pattern forming method according to claim 1, wherein in the second gas exposure step, the resist pattern is exposed to the second gas under atmospheric pressure. After the resist pattern forming step and before the first gas exposure step, adsorption for forming an adsorption prevention layer covering the surface of the convex portion of the resist pattern and the exposed surface on the first surface side exposed through the concave portion. Further has a preventive layer forming step,
The pattern forming method according to claim 1 or 2, wherein the adsorption prevention layer prevents the inorganic element-containing compound from adsorbing on the surface of the resist pattern . A resist pattern forming step of forming a resist pattern having a plurality of convex portions and concave portions on the first surface of a base material having a first surface and a second surface facing the first surface.
After the resist pattern forming step, an adsorption prevention layer forming step of forming an adsorption prevention layer covering the surface of the convex portion of the resist pattern and the exposed surface on the first surface side exposed via the concave portion.
After the adsorption prevention layer forming step, the resist pattern is exposed to a first gas containing an inorganic element-containing compound exhibiting Lewis acidity under predetermined conditions to change the atmosphere around the resist pattern to the first gas atmosphere. The first gas exposure step of chemically reacting the inorganic element-containing compound with the resist material constituting the resist pattern, and
After the first gas exposure step, a first gas purging step of exhausting the first gas from the periphery of the resist pattern and a first gas purging step.
It has a second gas exposure step of exposing the resist pattern to a second gas containing an oxidizing agent under predetermined conditions.
The adsorption prevention layer prevents the inorganic element-containing compound from adsorbing on the surface of the resist pattern.
A pattern forming method in which a series of steps including the first gas exposure step and the first gas purging step is repeated a plurality of times, and then the second gas exposure step is performed at least once. A claim for forming the resist pattern by performing an imprint process in a helium gas or cohesive gas atmosphere using an imprint mold having concave portions and convex portions corresponding to the convex portions and the concave portions in the resist pattern forming step. Item 6. The pattern forming method according to any one of Items 1 to 4. The pattern forming method according to any one of claims 1 to 4, wherein in the resist pattern forming step, the resist pattern is formed by an electron beam lithography method or a photolithography method. The pattern forming method according to any one of claims 1 to 6, wherein the substrate is a quartz glass substrate or a silicon substrate. A step of forming the pattern on the first surface of the base material by the pattern forming method according to any one of claims 1 to 7.
A method for manufacturing an uneven structure, which comprises a step of etching the first surface side of the base material using the pattern as a mask. The step of forming the pattern on the hard mask layer of the base material on which the hard mask layer is formed on the first surface by the pattern forming method according to any one of claims 1 to 7.
A step of forming a hard mask pattern by etching the hard mask layer using the pattern as a mask, and
A method for manufacturing an uneven structure, which comprises a step of etching the first surface side of the base material using the hard mask pattern as a mask. A method for manufacturing a replica mold using the uneven structure manufactured by the method for manufacturing a concave-convex structure according to claim 8 or 9 as a master mold.
The master mold and a transfer base material having a first surface and a second surface facing the master mold are prepared, and the uneven pattern of the master mold is transferred to the transfer material on the first surface of the transfer base material. Then, in the step of forming the uneven pattern by inverting the uneven pattern of the master mold,
A method for manufacturing a replica mold, which comprises a step of etching the first surface side of the transfer base material using the uneven pattern formed on the first surface of the transfer base material as a mask. The method for manufacturing a replica mold according to claim 10, wherein the substrate to be transferred is a quartz glass substrate. A resist pattern reformer that modifies a resist pattern having a plurality of protrusions and recesses.
A gas-exposed portion capable of exposing each of a first gas containing an inorganic element-containing compound exhibiting Lewis acidity and a second gas containing an oxidizing agent to the resist pattern under predetermined conditions.
A detection unit that detects the modified state of the resist pattern due to exposure to the first gas, and
A control unit for controlling the exposure of the first gas and the exposure of the second gas in the gas exposure unit is provided.
The control unit exposes the first gas to the resist pattern to the gas-exposed unit to change the atmosphere around the resist pattern into the first gas atmosphere, and from the periphery of the resist pattern to the first. A resist pattern in which a series of processes consisting of a process of exhausting one gas is repeated a plurality of times, and then a process of exposing the second gas to the resist pattern is performed once based on the detection result by the detection unit. Reformer. The resist pattern reforming apparatus according to claim 12, wherein the detection unit detects a modified state of the resist pattern by changing the optical characteristics of the resist pattern. The resist pattern reforming apparatus according to claim 13, wherein the change in the optical characteristics of the resist pattern is a change in reflectance, a change in refractive index, a change in IR characteristics, or a change in color tone with respect to a light beam having a predetermined wavelength. The resist pattern reforming apparatus according to claim 12, wherein the detection unit detects a modified state of the resist pattern by changing the weight of the resist pattern. The first treatment condition data regarding the exposure treatment of the first gas to the resist pattern by the gas exposure unit, the second treatment condition data regarding the exposure treatment of the second gas, and the reformed state data regarding the modified state of the resist pattern. It also has a storage unit that stores in association with
The control unit exposes the first gas in the gas exposure unit and the first gas exposure unit based on the first processing condition data, the second processing condition data, and the modified state data stored in the storage unit. 2. The resist pattern reformer according to any one of claims 12 to 15, which controls exposure to gas. The storage unit stores electron density data relating to the electron density of the organic material constituting the resist pattern in association with the first processing condition data, the second processing condition data, and the modified state data. Item 16. The resist pattern reforming apparatus according to Item 16. The resist pattern reforming apparatus according to any one of claims 12 to 17.
A pattern forming system including a resist pattern forming apparatus for forming the resist pattern modified by the resist pattern modifying apparatus. The pattern forming system according to claim 18, further comprising an etching apparatus for etching a member to be processed using the resist pattern modified by the resist pattern modifying apparatus as a mask. The pattern forming system according to claim 18 or 19, wherein the resist pattern forming apparatus is an imprint apparatus or an electron beam drawing apparatus. The resist pattern reforming apparatus according to any one of claims 12 to 17.
A pattern forming system including an etching apparatus for etching a member to be machined using the resist pattern modified by the resist pattern reforming apparatus as a mask.

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