JP2012150441A - Resist developer, formation method for resist pattern, and manufacturing method for mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce necessary exposure at the time of forming a resist pattern showing a desired resolution by using a resist layer having a prescribed composition.SOLUTION: The resist developer used at the time of irradiating a resist layer containing a polymer of α-chloro-acrylic ester and α-methyl styrene with energy beams so as to be exposed and developed includes an alcohol solvent A, and a solvent B made of n-amyl acetate or ethyl acetate or the admixture thereof.

Description

  The present invention relates to a resist developer, a resist pattern forming method, and a mold manufacturing method, and more particularly to a developer and a developing method when forming a pattern on a resist.

  Conventionally, in magnetic media used in hard disks and the like, a technique has been used in which magnetic particles are miniaturized, the magnetic head width is minimized, and data tracks on which information is recorded are narrowed to increase the recording density. On the other hand, there is an increasing demand for higher recording density, and in this magnetic medium, the magnetic influence between adjacent tracks cannot be ignored. For this reason, the conventional method has a limit in increasing the recording density.

  In recent years, a new type of media called patterned media in which data tracks of magnetic media are formed by magnetic separation has been proposed. The patterned media is intended to improve the signal quality by removing the magnetic material unnecessary for recording and achieve a higher recording density.

  Recently, as this patterned medium, a type of medium called Discrete Track Recording Media (hereinafter referred to as DTR medium) in which data tracks of a magnetic disk are magnetically separated has been proposed. .

  On the other hand, this DTR media has been developed with higher density and is called “bit patterned media” (magnetic media for recording signals as bit patterns (dot patterns) Bit Patterned Media; hereinafter referred to as BPM)). Some types of media have also been proposed.

  As a technique for mass-producing this patterned media, a master mold or a master mold as a master mold is used to transfer a pattern of a working replica that has been copied and copied once or multiple times to a transfer target (here, a magnetic medium). Thus, an imprint technique for producing patterned media is known. Hereinafter, the master mold and the working replica are collectively referred to as a mold. Further, since this imprint technique is often used on the nano order, it is also called a nanoimprint technique.

  As a resist pattern forming method for manufacturing this imprint mold, for example, in Patent Document 1, ZEP520A (manufactured by Zeon Corporation) (α-methylstyrene and α-chloroacrylic acid) is used as a resist on a quartz substrate. A technique is described in which a resist layer is formed by applying a methyl copolymer), the resist layer is exposed by electron beam drawing, and the resist developer is acetic acid-n-amyl.

  As a related technique, a technique using a mixed solution of methyl isobutyl ketone and isopropanol as a developer of ZEP520A is known as a technique used in semiconductor manufacturing (see, for example, Patent Document 2).

  Further, as a related technique, a technique using isopropanol as a developer of ZEP520 is known as a technique used for manufacturing patterned media (for example, see Non-Patent Document 1).

JP 2009-226762 A JP 2000-039717 A

XiaoMin Yang et. al. J. et al. Vac. Sci. Technol. B 25 (6), Nov / Dec 2007 p. 2202

However, when ZEP520A (resist made of a copolymer of α-methylstyrene and α-methyl chloroacrylate) is developed with a developer made of acetic acid-n-amyl, the electron beam-drawn part (hereinafter referred to as “electron beam drawing site”) , A resist-dissolved portion) and a line-and-space fine pattern with a width ratio of 1 to 2 formed in the resist layer, where the electron beam is not drawn (hereinafter referred to as a resist non-dissolved portion). Even if it is going to be, about 26 nm was a value used as a limit in practical use as a line width of the resist melt | dissolution part in a resist layer. Hereinafter, this value is referred to as resolution. At that time, the exposure amount (hereinafter referred to as “required exposure amount”) by electron beam drawing necessary to form the width of the resist-dissolved portion was about 120 μC / cm ² (acceleration voltage 100 kV).
The structure of the resist layer formed by the resist dissolving portion and the resist non-dissolving portion is referred to as a resist pattern.

In addition, when a mixed solution of methyl isobutyl ketone and isopropanol of Patent Document 2 and a mixture of 56 to 44 (volume mixing ratio) of methyl isobutyl ketone to isopropanol is used as a developer, the resolution is 20 nm. It was. The necessary exposure amount for forming the width of the resist dissolving portion was about 350 μC / cm ² (acceleration voltage 100 kV).

  That is, with the two types of developers described above, a resist pattern is formed with a relatively small amount of electron beam exposure, but the resolution remains at about 20 nm.

In contrast to the current situation, the magnetic recording density aimed for practical use with DTR media, which is one of patterned media, is generally 1 TeraBit / inch ² and the required track pitch is about 50 nm. In this case, the required resolution in a line-and-space pattern with a width ratio of 1: 2 is approximately 17 nm. Furthermore, the magnetic recording density aimed for practical use with BPM is equal to or higher than that of DTR media, and the required resolution is naturally higher than that.

On the other hand, when the isopropanol of Non-Patent Document 1 is used as a developer, the resolution is improved to 14 nm. However, the necessary exposure amount for forming the width of the resist dissolving portion is about 1150 μC / cm ² (acceleration voltage 100 kV). That is, when isopropanol is used as the developer, the desired resolution (17 nm) as described above can be achieved, but the necessary exposure amount for forming the resist-dissolved portion is acetic acid-n-amyl regardless of the resolution. Compared with the developer (120 μC / cm ² , acceleration voltage 100 kV), it increases considerably by 9.6 times (about 1150 μC / cm ² ).
As a result, a considerable time is required for the electron beam drawing process, and the master mold production efficiency is lowered.

  The object of the present invention has been made in consideration of the above-described circumstances, and reduces the required exposure when forming a resist pattern while providing a desired resolution for a resist layer having a predetermined composition. An object of the present invention is to provide a resist developer, a resist pattern forming method, and a mold manufacturing method.

  The inventors have achieved a desired resolution for a resist layer having a predetermined composition (a resist layer including a polymer of α-chloroacrylate and α-methylstyrene in the present embodiment) Various means for reducing the required exposure amount were studied.

As a result, as a developer, a mixture of a poor solvent having a very low dissolution rate in the resist layer and a solvent having a higher dissolution rate in the resist layer than that of the poor solvent but capable of considerably reducing the required exposure amount. Found to use. That is, by mixing the above-mentioned solvents and using them as a developer, the resolution can be improved mainly with a poor solvent, and the required exposure amount can be considerably reduced with other solvents. As a result, it was found that the required exposure amount can be considerably reduced while obtaining a desired resolution.
Based on the above knowledge, the present inventors have devised means that can solve the above-mentioned problems.

The embodiment of the present invention based on this finding is as follows.
The first aspect of the present invention is:
A resist developer used for developing a resist layer containing a polymer of α-chloroacrylic acid ester and α-methylstyrene by irradiating the resist layer with an energy beam,
A resist developer comprising an alcohol solvent A and a solvent B composed of n-amyl acetate, ethyl acetate, or a mixture thereof.
According to a second aspect of the present invention, in the invention according to the first aspect,
The solvent A is isopropanol.
The third aspect of the present invention is:
Forming a resist layer containing a polymer of α-chloroacrylate and α-methylstyrene on the substrate;
Irradiating the resist layer with an energy beam to expose a predetermined pattern;
A step of developing the exposed resist layer with a developer containing an alcohol solvent A and a solvent B composed of acetic acid-n-amyl or ethyl acetate or a mixture thereof. It is a forming method.
According to a fourth aspect of the present invention, in the invention according to the third aspect,
The exposure step is a step of performing electron beam drawing,
The resist layer is a resist having sensitivity to an electron beam.
According to a fifth aspect of the present invention,
Forming a resist layer containing a polymer of α-chloroacrylate and α-methylstyrene on the substrate;
Irradiating the resist layer with an energy beam to expose a predetermined pattern shape;
A step of developing the exposed resist layer with a developer containing an alcohol solvent A and a solvent B made of acetic acid-n-amyl or ethyl acetate or a mixture thereof. Is the method.

  ADVANTAGE OF THE INVENTION According to this invention, the required exposure amount at the time of forming a resist pattern can be reduced, providing desired resolution with respect to the resist layer which has a predetermined composition.

It is a cross-sectional schematic diagram for demonstrating the manufacturing process of the mold which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the present embodiment, description will be given in the following order using FIG.
1. Manufacturing method of master mold a) Preparation of substrate b) Formation of hard mask on substrate c) Formation of resist layer d) Pattern drawing e) Development f) Rinse and drying g) Removal of remaining film layer in resist layer h) Hard Etching to mask (first etching)
i) Etching to substrate (second etching)
j) Removal of resist pattern k) Removal of hard mask l) Cleaning and drying 2. Effects of the embodiment Modified example

<1. Manufacturing method of master mold>
a) Preparation of Substrate In the present embodiment, the substrate 1 in FIG. 1A is a working mold used for manufacturing a magnetic recording medium having a plurality of tracks or for manufacturing a magnetic recording medium having a plurality of tracks. It is a board | substrate used as the master mold 20 used when manufacturing by imprint. That is, it is a substrate serving as an imprint mold for creating DTR media and BPM by the imprint method.
In the present embodiment, description will be made using a substrate 1 made of wafer-shaped quartz. Hereinafter, this wafer-shaped quartz substrate is simply referred to as substrate 1.

b) Formation of Hard Mask on Substrate First, the substrate 1 (FIG. 1A) that has been appropriately polished and cleaned as necessary is introduced into a sputtering apparatus. In the present embodiment, a target made of chromium (Cr) is sputtered with argon gas and nitrogen gas to form a hard mask 2 made of chromium nitride (FIG. 1B).

  Here, the hard mask 2 preferably has good adhesion to the resist layer 3 containing a polymer of α-chloroacrylic acid ester and α-methylstyrene. The hard mask 2 preferably has good etching selectivity with the resist layer 3 containing a polymer of α-chloroacrylic acid ester and α-methylstyrene. In addition, the thickness of the hard mask 2 at this time is preferably a thickness that remains until etching of the substrate 1 is completed.

The “hard mask” here refers to a layered material composed of a single layer or a plurality of layers and used for etching on a substrate.
As an example of the “plural layers”, the hard mask may include a conductive layer, an antioxidant layer, an adhesion auxiliary layer, and the like. Note that the antioxidant layer in the hard mask may also serve as a conductive layer. In that case, the conductive layer can be omitted.

c) Formation of resist layer The substrate 1 on which the hard mask 2 is formed is appropriately washed, and a dehydration baking process before resist coating or formation of the adhesion auxiliary layer or the like is performed as necessary to improve adhesion. .
Thereafter, in the present embodiment, as shown in FIG. 1C, a resist containing a polymer of α-chloroacrylate and α-methylstyrene is applied to the substrate 1 on which the hard mask 2 is formed. Then, a resist layer 3 is formed.
In addition, as this (alpha) -chloroacrylic acid ester, you may use what has a general acrylic acid ester structure ((alpha) -chloroacrylate methyl, (alpha) -chloroacrylic acid ethyl, etc.). Specific examples include methyl α-chloroacrylate used in ZEP520A-7 (manufactured by Nippon Zeon Co., Ltd.). In the present embodiment, an example using methyl α-chloroacrylate will be described.

  In the present embodiment, a spin coat method is used for coating when forming the resist layer 3. Specifically, the resist solution is dropped onto the main surface of the substrate 1 on which the hard mask 2 is formed, and then the substrate 1 is rotated at a predetermined rotational speed to form the resist layer 3. Next, the substrate 1 on which the resist layer 3 is spin-coated is baked at a predetermined temperature and time on a hot plate. Thereafter, the resist layer 3 is formed by, for example, transferring it onto a cooling plate kept at room temperature (22.5 ° C.), cooling it, and drying it.

  In addition, the thickness of the resist layer 3 at this time is preferably such a thickness that the resist layer remains until etching of the hard mask 2 formed on the substrate 1 is completed. This is because etching to the hard mask 2 removes not only the portion corresponding to the resist dissolution portion formed in the resist layer 3 but also the resist layer 3 in the resist non-dissolution portion.

d) Pattern drawing Next, a desired pattern is drawn on the resist layer 3 using an electron beam drawing apparatus.
After the coating step, a desired pattern is drawn on the resist layer 3 using an electron beam exposure (drawing) apparatus. A desired resist pattern can be formed by performing e) development described later.

  In the present embodiment, a positive resist is used for the resist layer 3. For this reason, the portion where the electron beam is drawn becomes the resist dissolving portion.

The shape of this electron beam drawing is not particularly limited, but when a DTR media is produced, it becomes a line shape in order to form a line and space. And in the case of BPM, it becomes a dot shape. Of course, in order to form a data pattern or a servo pattern, electron beam drawing in which a line shape and a dot shape are mixed may be performed.
In this embodiment, the case of exposure by electron beam drawing will be described, but this embodiment can be applied to other exposures. Hereinafter, exposure by electron beam drawing is also simply referred to as “exposure”.

e) Development After a desired fine pattern is drawn with an electron beam, the resist layer 3 is developed with a predetermined developer as shown in FIG. ) Is removed, and a resist pattern 4 corresponding to a desired fine pattern is formed.

  Here, in this embodiment, the resist layer in the resist dissolving portion is developed by using a developer containing two kinds of solvents, alcohol solvent A, solvent B composed of acetic acid-n-amyl or ethyl acetate, or a mixture thereof as the developer. Is dissolved and removed, and the exposed resist layer 3 is developed.

  In this embodiment, isopropanol is used as the solvent A, and acetic acid-n-amyl is used as the solvent B. And the case where the liquid mixture of these solvent A and solvent B is used for a developing agent is demonstrated below.

  From the relationship between the exposure amount required for resist dissolution and resolution, the desired resolution can be maintained by using the above-mentioned solvent A and solvent B, compared to the case where only isopropanol or only acetic acid-n-amyl is used as the developer. However, the remarkable effect that the required exposure amount can be considerably reduced can be obtained.

  By reducing the required exposure amount, the electron beam drawing time can be shortened, the productivity of electron beam drawing can be greatly improved, or the output (current value) of the electron beam is reduced. It becomes possible to draw a more precise pattern.

  The reason why the developer of the present embodiment has succeeded in maintaining the resolution and reducing the required exposure amount is intensively studied than when isopropanol or n-amyl acetate alone is used as the developer. It is. However, it is presumed that the surface tension and viscosity of isopropanol and acetic acid-n-amyl and the compatibility have an influence.

Specific examples of the development process for the resist layer 3 include the following methods.
That is, the hard mask 2 and the resist layer 3 are provided, and the substrate 1 on which a desired pattern is drawn with an electron beam is rotated at a predetermined rotational speed. Then, a developer composed of a mixed solution of the solvent A and the solvent B is supplied dropwise from above the substrate 1. At this time, the developer may be at room temperature or may be maintained at a predetermined temperature. During the dropping of the developer, dissolution of the resist dissolving portion by the developer occurs.
In addition, even after the dissolution of the resist dissolving portion is completed, the developer containing the resist melt is kept by dripping the developer excessively while rotating the substrate 1. Flows down from the outer edge of the substrate. Further, by continuing to dripping the developer excessively while rotating the substrate 1, the developer containing the resist solution is replaced with the developer not containing the resist solution, and a clean resist pattern is formed. .

  In addition, isopropanol as the solvent A mentioned here is a poor solvent having a very low dissolution rate with respect to a resist layer containing a polymer of α-chloroacrylate and α-methylstyrene. By using a poor solvent, the dissolution rate of the resist layer 3 as a whole developer can be lowered. By doing so, unnecessary dissolution of the resist non-dissolved part due to the excessively high dissolution rate can be suppressed, and as a result, the resolution can be improved. Further, the alcohol solvent A that satisfies the above requirements has a relatively low surface tension and viscosity. Therefore, it is easy to enter a very small gap, and even when the electron beam drawing portion (resist dissolving portion) is extremely fine, the resist layer 3 can be digged while being dissolved, and a nano-order extremely fine resist pattern 4 is formed. it can.

Further, the other solvent B may be a solvent in which the dissolution rate of the resist layer 3 is higher than that of the solvent A, even if it is not acetic acid-n-amyl. Further, when a developer is used as a mixed solution with the solvent A, it is necessary to form the resist pattern 4 (to dissolve the resist dissolving portion) as compared with the case where the solvent B is used as a developer alone. It is sufficient if the exposure amount is small.
Therefore, ethyl acetate can be used instead of acetic acid-n-amyl, or a mixture of two solvents of acetic acid-n-amyl and ethyl acetate may be used as the solvent B. Of course, compounds other than these may be applicable as the solvent B, but are currently under investigation.

  In the present embodiment, only two types of solvents, solvent A and solvent B, are used, but other solvents may be mixed in addition to these solvents. For example, a compound that is a poorer solvent for the resist layer 3 than the solvent A and a compound having a higher affinity between the solvent A and the solvent B may be mixed. At that time, it is preferable if the required exposure amount is lower than that of the solvent B, and in addition, if the required exposure amount is lower than that of the solvent B, it is more preferable.

f) Rinsing / Drying Immediately after stopping the dropping of the developer, the rinse agent is dropped and supplied from above the substrate 1 while rotating the substrate 1 in order to wash away the developer.
The rinsing agent is preferably supplied dropwise before stopping the dropping of the developer. By doing so, it is possible to prevent the developer from being instantly replaced with the rinse agent, and the resist melt remaining in the developer staying on the substrate to be precipitated again and become dirty.
In addition, it is preferable to use a solvent having a small surface tension for the rinse agent. By using it as a rinse agent, pattern collapse in the drying process described below can be prevented or reduced. Note that the same material as the solvent A of the developer may be used.

And the drying process is performed with respect to the board | substrate 1 which performed said rinse process. This drying process is performed by rotating the substrate 1 at a predetermined rotational speed after stopping the dripping supply of the rinse agent after performing the rinse process. As a result, the rinse agent flows down from the outer edge of the substrate or evaporates due to centrifugal force. In this way, the substrate 1 with the hard mask 2 on which the resist pattern 4 including the desired resist-dissolved portion and the resist non-dissolved portion is formed is obtained.
A drying step is performed as necessary for the purpose of removing the developer or rinse agent remaining in the formed resist pattern 4 and improving the adhesion between the resist pattern 4 and the hard mask 2. Next, a baking process may be performed.

g) Removal of remaining film layer in resist layer Thereafter, the substrate 1 with the hard mask 2 on which the resist pattern 4 is formed is introduced into a dry etching apparatus. Then, a treatment with a mixed gas of oxygen gas and argon (Ar) gas is performed to remove the residue (scum) of the resist dissolving portion. Here, instead of the oxygen gas, for example, a fluorine-based gas such as CH ₄ may be used. Further, helium (He) may be added.

h) Etching to hard mask (first etching)
Subsequently, after exhausting the gas used in the removal of the remaining film layer in the resist layer, first etching is performed with a mixed gas composed of chlorine gas and oxygen gas. Thereby, the hard mask 2 in the exposed portion is removed by the development process and the removal of the remaining film layer.
Thus, as shown in FIG. 1E, etching corresponding to the resist pattern 4 is performed on the hard mask 2 on the substrate 1.
Note that the etching end point at this time is determined by using, for example, a reflection optical end point detector or a plasma monitor.

i) Etching to substrate (second etching)
Subsequently, after exhausting the gas used in the first etching, second etching using a fluorine-based gas is performed on the substrate 1. Then, as shown in FIG. 1 (f), etching corresponding to the resist pattern 4 is performed on the substrate 1, and the hard mask 2 and the mold 10 before the resist pattern 4 is removed except for the etched portion are removed. Produced.

Note that the fluorine-based gas used here includes CxFy (for example, CF ₄ , C ₂ F ₆ , C ₃ F ₈ ), CHF ₃ , a mixed gas thereof, or a rare gas (He, Ar, Xe) as an additive gas thereto. Etc.).

j) Removal of resist pattern Subsequently, the remaining resist pattern 4 is removed with a resist stripper made of a mixed solution of sulfuric acid and hydrogen peroxide.
Specifically, the substrate 1 is immersed in the resist stripper for a predetermined time, and then the resist stripper is washed away with a rinse agent (in this case, room temperature or heated pure water). Next, the substrate 1 is dried by the same method as the drying process.

In addition, as a resist remover used here, in addition to the above-mentioned mixed solution of sulfuric acid and hydrogen peroxide solution, an organic solvent (in the case of a resist containing a polymer of α-chloroacrylate ester and α-methylstyrene, anisole) is used. Or, N, N-dimethylacetamide (ZDMAC (manufactured by Nippon Zeon Co., Ltd.)), ozone water, etc. Any compound can be used as long as it is a compound that can swell and dissolve or chemically decompose and remove it. The stripping agent may be heated to increase the resist stripping removal capability, or may be an ashing process using oxygen plasma.
The resist pattern 4 may be removed after the first etching process and before the second etching process.

k) Removal of Hard Mask Subsequently, a step of peeling and removing the hard mask 2 remaining on the mold 10 before the remaining hard mask removal is performed by the same method as the first etching. When there is a chemical solution that can be dissolved and removed by the hard mask 2, the hard mask 2 may be removed using the chemical solution.

l) Cleaning and drying After the above steps, the substrate 1 is cleaned and dried, if necessary. In this way, a master mold 20 as shown in FIG. 1G is completed.

<2. Advantages of the embodiment>
In the present embodiment as described above, the following effects can be obtained.
That is, a poor solvent (solvent A) having a very low dissolution rate in the resist layer is mixed with a solvent (solvent B) that has a higher dissolution rate in the resist layer than that of the poor solvent but can significantly reduce the required exposure. By using the toner as a developer, the resolution can be improved and the required exposure can be considerably reduced.

  By reducing the required exposure amount, the electron beam drawing time can be shortened, the productivity of electron beam drawing can be greatly improved, or the output (current value) of the electron beam is reduced. It becomes possible to draw a more precise pattern.

<3. Modification>
The technical scope of the present invention is not limited to the above-described embodiment, and various modifications and improvements are added within the scope of deriving specific effects obtained by the constituent elements of the invention and combinations thereof. Including.
Hereinafter, modifications other than the above will be listed.

  First, the shape of the substrate 1 may be other than the wafer shape. The substrate 1 may be rectangular, polygonal, semicircular when viewed from the plane (upper surface), or rectangular or rectangular when viewed from the side. Any substrate that has been processed into a trapezoidal shape or the like may be used as long as it is easily and stably fixed as a mold to the imprint apparatus. Further, the main surface may have a platform terrain (mesa structure or pedestal) whose peripheral edge is slightly lower than the pattern forming region of the mold main surface.

  With regard to the transparency of the substrate 1, it is preferably a transparent or translucent substrate in consideration of the ease in producing the working replica described above. As for the material of the substrate 1, any material or structure may be used as long as it can be used as the master mold 20 made of a metal such as quartz, sapphire, or Si, plastic, ceramic, or a combination thereof. Absent.

  In addition, the resist in this embodiment may be not only a positive resist but also a negative resist as long as it has reactivity when exposed by irradiation with an energy beam. Specifically, it may be a resist that needs to be developed with a developer, and may be a resist having sensitivity to ultraviolet rays, X-rays, electron beams, ion beams, proton beams, and the like.

  In this embodiment, a hard mask is provided on the substrate. However, when the substrate 1 can be etched using the resist pattern 4 as a mask material without the need for the hard mask 2, the resist layer 3 may be formed directly on the substrate 1. good. In this case, the resist layer 3 may be provided on the substrate 1 after the dehydration baking process or the formation of the adhesion auxiliary layer.

  In the etching in this embodiment, only a part of etching may be wet etching, and other etching may be dry etching, or all etching may be wet etching or dry etching. Further, when the pattern size is in the micron order, wet etching may be introduced according to the pattern size, such as wet etching at the micron order stage and dry etching at the nano order stage.

In this embodiment, the description has been made focusing on a resist containing a polymer of α-chloroacrylic acid ester and α-methylstyrene, but the technical idea of the present invention is not limited to this type of resist. It is guessed. That is, it is estimated that the solvent A and the solvent B constituting the developer for the resist can be set each time depending on the type of the resist. Further, even if the alcohol compound mentioned in the present embodiment is not used, if another compound is used as the solvent A and a compound having a resist solubility higher than that of the solvent A is used as the solvent B, it is described in the present embodiment. There is a possibility of having the effect of.
The technical idea of the present invention has been intensively studied by the inventors.

  Further, the developer, resist pattern forming method, and mold manufacturing method in this embodiment can be suitably applied to the following uses other than mold manufacturing. For example, photomasks for semiconductor devices, semiconductor manufacturing, micro electro mechanical systems ( MEMS), sensor elements, optical discs, optical components such as diffraction gratings and polarizing elements, nanodevices, organic transistors, color filters, microlens arrays, immunoassay chips, DNA separation chips, microreactors, nanobiodevices, optical waveguides, optical filters It can be widely applied to the production of photonic crystals and the like.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Hard mask 3 Resist layer 4 Resist pattern 10 Residual hard mask and mold before removing resist layer 20 Mold (master mold)

Claims (5)

A resist developer used for developing a resist layer containing a polymer of α-chloroacrylic acid ester and α-methylstyrene by irradiating the resist layer with an energy beam,
A resist developer comprising: an alcohol solvent A; and a solvent B composed of acetic acid-n-amyl or ethyl acetate or a mixture thereof.   The resist developer according to claim 1, wherein the solvent A is isopropanol. Forming a resist layer containing a polymer of α-chloroacrylate and α-methylstyrene on the substrate;
Irradiating the resist layer with an energy beam to expose a predetermined pattern;
A step of developing the exposed resist layer with a developer containing an alcohol solvent A and a solvent B composed of acetic acid-n-amyl or ethyl acetate or a mixture thereof. Forming method. The exposure step is a step of performing electron beam drawing,
4. The method of forming a resist pattern according to claim 3, wherein the resist layer is a resist having sensitivity to electron beams. Forming a resist layer containing a polymer of α-chloroacrylate and α-methylstyrene on the substrate;
Irradiating the resist layer with an energy beam to expose a predetermined pattern shape;
A step of developing the exposed resist layer with a developer containing an alcohol solvent A and a solvent B made of acetic acid-n-amyl or ethyl acetate or a mixture thereof. Method.

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