JP2002150620A - Stamper manufacturing method - Google Patents

Abstract

(57) [Problem] To provide a method of manufacturing a stamper using a resist composition capable of obtaining a pattern with high resolution and high dimensional accuracy. As a resist composition, a composition having (a) a compound which generates an acid upon exposure, and (b) a medium having a medium whose alkali solubility is increased by a reaction induced by exposure or heat treatment after exposure and exposure. And the weight average molecular weight (Mw) of the medium and the weight average molecular weight (Mwe) after the reaction induced by exposure or heat treatment after exposure and exposure.
x), the positive resist film 103 using a medium having a ratio (Mw / Mwex) of 2 or more is irradiated with an electron beam 104 and developed to form a resist pattern 106, and a concave portion is formed on the substrate using the pattern as a mask. A method of manufacturing a stamper including a step of forming a stamper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a stamper for manufacturing an optical disk.

[0002]

2. Description of the Related Art In recent years, with the rapid development of information communication and image processing techniques, there has been an increasing need for a technique for recording large-capacity digital information such as higher-definition image information. As a current information recording technique, an optical disc such as a compact disc (CD) or a digital video disc (DVD) is used as a medium having the largest storage capacity. In order to further increase the capacity, technical developments such as miniaturization of pit processing of an optical disk master and improvement of an optical head have been promoted.

Here, an example of a method for manufacturing a stamper for manufacturing an optical disk will be described. An uneven pattern is formed on a photoresist coating film provided on the substrate by exposing and developing a predetermined pattern, and the substrate is etched using this pattern as a mask to obtain an optical disk master. A conductive layer is formed by sputtering or chemical plating on the uneven pattern surface of the master optical disk, and a plating layer is formed on the conductive layer by electroplating or the like, and the metal master portion composed of the conductive layer and the plating layer is peeled off. To be a metal master. Further, a mother with a reversed surface is manufactured from a metal master, and a stamper with a reversed surface is further manufactured from the mother. A large number of optical disks are duplicated using this stamper. The method of manufacturing the stamper is described in Japanese Patent Application Laid-Open No. 8-45118.

In the conventional pit processing for manufacturing a master optical disk, a desired pit pattern is formed by exposing a resist on a rotating substrate with a laser beam having a wavelength of 350 to 460 nm. To make pits smaller,
A pit pattern processing technology by shortening the laser wavelength (180 to 300 nm) is being studied. However, it is difficult to achieve a pit line width of 100 nm or less when the wavelength of the laser is shortened. Therefore, a pit forming method using an electron beam having excellent fine workability is expected.

[0005] The minimum processing size by electron beam exposure depends on the beam diameter, and a high resolution of nanometer level can be obtained. However, in electron beam exposure, the energy sensitivity of the resist is significantly lower than that in laser exposure, so that the sensitivity of the resist is low. In addition, the throughput is low because it is performed in a vacuum. As a method of improving the throughput, it is important to improve the performance of the resist used, as well as the improvement of the apparatus. Therefore, a resist exhibiting high sensitivity and high resolution is demanded for an electron beam exposure apparatus.

As a resist material for solving these problems, a composition containing a compound capable of generating an acid upon irradiation with an ultraviolet ray, an electron beam or the like and a medium which changes the solubility in a developing solution by a catalytic action of the acid is disclosed in US Pat. 377977
No. 8 and JP-A-59-45439. According to these descriptions, a compound or a polymer containing a protecting group (acetal, t-butoxycarbonyl group, etc.) that can be deprotected (separated) by an acid is disclosed as a medium for changing the solubility.

[0007] Resists composed of such a composition are called chemically amplified resists, and can be broadly classified into two types, ie, a two-component type and a three-component type. The former is a resist containing, as an essential component, a compound that generates an acid and a polymer in which the above-described protective group is introduced as an acid-decomposable bond to an alkali-soluble group in an alkali-soluble polymer. In this resist, the above-mentioned polymer component that is not dissolved in an aqueous alkali solution separates a protective group by a catalytic reaction of a small amount of acid generated by exposure, and a positive-type pattern is formed with an alkali developing solution in order to regenerate an alkali-soluble polymer. Can be formed.

On the other hand, the latter three-component resist contains, as essential components, an acid-generating compound, an alkali-soluble resin, and a polymer or compound having a protective group. The principle of the formation of a positive pattern by the three-component resist is that the alkali-soluble resin is hardly alkali-soluble in the non-exposed area due to the dissolution inhibiting action of the polymer or the compound and the catalytic reaction of the acid generated in the exposed area causes the above-mentioned reaction. It is based on a reaction in which the alkali-inhibiting action of the polymer or compound is lost and the alkali solubility of the resin is restored.

Most of the chemically amplified positive resists are two-component resists. For the purpose of further improving the resolution, a resin obtained by further crosslinking an alkali-soluble resin containing a protecting group which can be deprotected by an acid and further crosslinking with an acetal group is used. A resist composition used has been proposed (JP-A-11-344808).

As can be seen from the above prior art, in a chemically amplified resist, both a two-component resist and a three-component resist mainly contain an alkali-soluble polymer (including one that becomes alkali-soluble by exposure). These polymers are
It is composed of molecules having various molecular weights. As a result, it has been found that molecules having different molecular weights have different solubilities in a developing solution, so that an unevenness (roughness) shape is formed on an edge of a resist pattern after development, which causes a reduction in dimensional accuracy.

As a pattern-forming material for avoiding this, as described in JP-A-6-266099, the weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight dispersity (Mw / Mn) of an alkali-soluble polymer are described. ) Is known. Thereby, the roughness of the resist pattern can be improved to some extent.

[0012]

In the above prior art, since a resist composition using an alkali-soluble polymer whose molecular weight characteristics are controlled as a main component is used, the content of a low-molecular-weight component having high alkali-solubility is significantly reduced. No consideration has been given to the fact that the dissolution rate of the entire resin is reduced and the resolution and sensitivity of the resist are significantly reduced.

An object of the present invention is to provide a method of manufacturing a stamper using a resist composition capable of forming a pattern with high resolution and high dimensional accuracy.

[0014]

In order to achieve the above object, a method of manufacturing a stamper according to the present invention comprises a method of manufacturing a stamper by exposing a coating film of a resist composition applied on a substrate to light by exposure or heat treatment after exposure. Forming a resist pattern by forming an image and developing the resist pattern with an aqueous alkaline developer, and forming a concave portion on the substrate using the resist pattern as a mask. (B) a composition having a medium whose alkali solubility is increased by exposure or a reaction induced by exposure and heat treatment after exposure, and the weight average molecular weight (Mw) of the medium and the exposure or The ratio of the weight average molecular weight (Mwex) after the reaction induced by the exposure and the heat treatment after the exposure (Mwex) (M
(w / Mwex) is 2 or more.

Compounds that generate an acid upon exposure (hereinafter, referred to as compounds)
(Referred to as compound (a))) onium salts such as diaryliodonium salts, triarylsulfonium salts, trialkylsulfonium salts, and alkylarylsulfonium salts, various halogen compounds, compounds containing a plurality of phenolic hydroxyl groups, and alkylsulfonic acids. And sulfonic acid esters of N-hydroxyimide, and the like, but are not limited thereto. For example, there may be mentioned those described as compounds having the same effect in the literature of the above-mentioned conventional examples.

Examples of a medium whose alkali solubility is increased by the above reaction (hereinafter referred to as a component (b) medium) include a carboxyl group, a phenolic hydroxyl group, and an alcoholic hydroxyl group in which a hydrogen atom of a chain hydrocarbon is substituted with fluorine. A polymer or a compound containing at least two alkali-soluble groups in one molecule (the same or different alkali-soluble groups in one molecule) is contained in one molecule of at least two vinyl ether groups. A polymer obtained by subjecting a compound to an acid-catalyzed addition reaction is exemplified.

The polymer having an alkali-soluble group includes, for example, (b1) a novolak resin obtained by polymerizing a phenol having a phenolic hydroxyl group as a substituent with an aldehyde, and (b2) a single polymer of vinylphenol. Copolymers with copolymerized and vinylphenol components such as acrylic acid, acrylic acid derivatives, methacrylic acid, methacrylic acid derivatives, styrene, styrene derivatives, maleic anhydride, maleic imide derivatives, acrylonitrile and the like, b3) 4-vinyl-2-chlorophenol, 4-vinyl-2,6-dichlorophenol, 4
-Vinyl-2-bromophenol, 4-vinyl-2,6
-Halogenated vinylphenol polymers and copolymers of vinylphenols such as dibromophenol alone or in combination of two or more kinds, and (b4) a monomer of a carboxyl group-containing monomer such as acrylic acid, methacrylic acid, crotonic acid, and itaconic acid. Homopolymers, copolymers thereof, and these monomers and other copolymerizable monomers (for example, b2, b
(B5) homopolymerization of styrene having a hexafluoroisopropyl group as a substituent, styrene having a hexafluoroisopropyl group as a substituent and another copolymerizable monomer Copolymerization with a monomer (for example, the monomers described in b2, b3 and b4 above), a homopolymer of an unsaturated bridged hydrocarbon monomer having a hexafluoroisopropyl group as a substituent, and a hexafluoroisopropyl group. The unsaturated bridged hydrocarbon monomer having a substituent and another copolymerizable monomer (for example, b2, b
And the monomers described in 3, b4).

The above-mentioned alkali-soluble polymer desirably has a weight average molecular weight (Mw) of 2000 or less. When the weight average molecular weight exceeds 2,000, the resist using the polymer obtained by the acid catalyzed reaction with the vinyl ether compound as the base resin increases the roughness of the resist pattern due to the molecular weight distribution of the alkali-soluble polymer. The effect of the invention is reduced. As the alkali-soluble polymer,
Non-polymeric monomers may also be used. The monomer may be more precisely a compound having an alkali-soluble group as described below, but it is complicated to repeatedly describe the same monomer, so that it is described in a polymer. Therefore, the lower limit of the weight average molecular weight (Mw) is up to the molecular weight of each monomer described above.

As the compound having an alkali-soluble group, a specific phenol compound can be used. That is, those having three or more benzene rings, three or more hydroxyl groups, and two or less hydroxyl groups in one benzene ring are preferable. For example, tris (4-hydroxyphenyl) methane, tris (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, α, α, α′-tris (4-hydroxyphenyl) -1- Ethyl-4-isopropylbenzene,
2,6-bis [(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol, 2,2'-methylenebis [6-[(2-hydroxy-5-methylphenyl) methyl] -4-methyl Phenol], 4- [bis (4-hydroxyphenyl) methyl) -2-methoxyphenol, 4,4 ', 4 ", 4"'-(1,2-ethanediylidene) tetrakisphenol, 4,4 ', 4 " ,
4 "'-(1,2-ethanediylidene) tetrakis [2
-Methylphenol], 4,6-bis [(4-hydroxyphenyl) methyl] -1,3-benzenediol,
2,6-bis (4-hydroxyphenyl) methyl-4-
Methylphenol, 4,4 ', 4 ", 4"'-(1,4
-Phenylenedimethylidine) tetrakisphenol, C
-Undecyl calix [4] resorcin arene, methyl calix [4] resorcin arene, and hydroxyphenol, hydroxyalkylbenzyl, dihydroxybenzyl, halogen, alkyl, cycloalkyl, alkoxy, acyl, acyloxy, nitro, cyano And compounds having at least one substituent selected from acyl halide, carboxyl, alcohol, alkyl halide and the like.

The compound containing a vinyl ether group to be reacted with a polymer or compound having an alkali-soluble group includes a compound containing at least two or more vinyl ether groups in one molecule. For example, resorcinol, catechol, phenols having two or more phenolic hydroxyl groups such as hydroquinone, phloroglucin,
Pyrogallol, phenols having three or more phenolic hydroxyl groups such as hydroxyhydroquinone, bisphenols, trisphenols, trinuclear phenols, and some or all of the hydrogen atoms of the hydroxyl groups of tetrakisphenols are ethyl vinyl ether groups, At least one selected from a methyl vinyl ether group and a vinyl ether group
Compounds substituted by type can be used. Further, in the cycloalkanes, biphenyls, naphthalenes and anthracenes, some or all of the hydrogen atoms of the hydroxyl group of the compound having two or more hydroxyl groups or glycoloyl groups are selected from an ethyl vinyl ether group, a methyl vinyl ether group and a vinyl ether group. Compounds substituted with at least one kind can also be used.

A polymer obtained by reacting the above-mentioned polymer or compound having an alkali-soluble group with a vinyl ether compound in the presence of an acid catalyst (ie, a medium of the component (b)) and a compound capable of generating an acid upon exposure (ie, (( The resist composition comprising the compound (a)) is treated, for example, as follows. A solution of the resist composition is applied to the substrate by a spin coating method, baked at 100 ° C. for 2 minutes,
Form a thin film. The amount of the acid-generating compound (compound (a)) is preferably about 2 to 10 parts by weight, and more preferably about 5 to 10 parts by weight based on 100 parts by weight of the total amount of the polymer. More preferred. Further, as the substrate, a silicon wafer, a quartz substrate, a photomask substrate, or various semiconductor wafers can be used.

The above thin film is exposed at a light exposure of 100 mJ / cm ² by a 500 W Xe-Hg lamp (made by Ushio Inc.) and an interference filter of 250 nm (made by Nippon Vacuum Optical), and baked at 100 ° C. for 5 minutes. Next, the thin film was dissolved in tetrahydrofuran and subjected to gel permeation chromatography (GPC) to obtain a polystyrene-equivalent weight average molecular weight (Mwe) of the polymer after the acid-catalyzed reaction.
x) is determined.

The ratio (Mw / Mwex) between (Mwex) determined by the above method and the weight-average molecular weight (Mw) of the polymer before the acid-catalyzed reaction (Mw / Mwex) is 2 or more and 30 or less. ) It is desirable as a component medium. The value of this ratio is 2
If it is smaller than this, it is difficult to obtain a sufficient effect of promoting alkali dissolution in the exposed portion of the resist, the resolution is deteriorated, and the effect of the present invention is hardly obtained. A more preferable value of Mw / Mwex is 2 or more and 20 or less.

For exposure, it is preferable to use electromagnetic waves such as far ultraviolet rays and X-rays, electron beams, ion beams and the like.

Solvents used for applying the above resist composition in the present invention include methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methoxypropionic acid. Examples include, but are not limited to, methyl, methyl ethoxypropionate, ethyl lactate, diacetone alcohol, cyclohexanone, 2-heptanone, and the like.

The resist composition of the present invention includes, for example, a surfactant for preventing striation (uneven coating) and improving developability, and a bisphenol and a trisphenol alkane for adjusting the dissolution rate of the resin. Low molecular weight phenol compounds such as trinuclear phenols and tetrakis phenols, compounds or polymers containing protecting groups (acetal group, ketal group, t-butoxycarbonyl group, etc.) which are deprotected (separated) by an acid catalyst, A storage stabilizer for the resist solution, a basic compound for suppressing diffusion of the acid catalyst to the non-exposed area, an ion dissociating compound such as onium halide, and a humectant such as tetraethylene glycol can be added.

The surface of the substrate can be treated with a medium for improving the adhesiveness between the resist composition and the substrate. Examples of this medium include hexamethyldisilazane, vinyltriacetoxysilane, 3-aminopropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, Various silane compounds such as γ-isocyanatopropyltriethoxysilane, polybutadiene, vinyl polymers obtained by epoxy-forming a rubber material having an unsaturated double bond such as polyisoprene, and the like, but are not limited thereto. .

[0028]

Next, specific examples and comparative examples of the present invention will be described. It should be noted that these embodiments are merely examples within the scope of the present invention, and the present invention is not limited only to these embodiments. (Synthesis example 1 of vinyl ether) dimethyl sulfoxide 50
3.5 g of phloroglucin was dissolved in ml. Add 10 ml to 4.0 g of sodium hydride (in 60% solid oil)
Add the hexane and dissolve the dispersion medium
The reaction was performed while stirring at 25 ° C. for 1 hour. Further, 13 g of 2-chloroethyl vinyl ether was added dropwise to the reaction solution, and the mixture was reacted at 70 ° C. for 12 hours. The reaction mixture is 1 liter of water
And extracted with 250 ml of diethyl ether,
6. The ether solution was washed with water and concentrated under reduced pressure to give a brown oil.
8 g were obtained.

This was purified by column chromatography using 80 g of silica gel and a mixed solution of hexane and ethyl acetate (hexane / ethyl acetate = 4/1) to obtain 3.57 g of the desired product as an oil. From the infrared absorption spectrum and the NMR spectrum analysis of this product, it was confirmed that all the hydrogen atoms of the three hydroxyl groups possessed by phloroglucin were substituted with an ethyl vinyl ether group. (Synthesis example 2 of vinyl ether) Similar results were obtained by using tris (4-hydroxyphenyl) methane instead of phloroglucin of Synthesis example 1 of vinyl ether described above. (Synthesis Example 3 of Vinyl Ether) Similar results were obtained by using vinyl chloride instead of 2-chloroethyl vinyl ether in Synthesis Example 1 of vinyl ether described above. (Synthesis example 1) An example of synthesis of a polymer obtained by subjecting a polymer having an alkali-soluble group and a compound having a vinyl ether group to an acid-catalyzed addition reaction will be described.

Polyvinyl phenol (Mw: 1800)
2 g and 0.8 g of the compound of Vinyl Ether Synthesis Example 1 were dissolved in 100 ml of ethyl acetate. Pyridinium p-
Toluenesulfonate (0.01 g) was added at 25 ° C for 24 hours.
Allowed to react for hours. Then, transfer the reaction solution to a separating funnel,
The mixture was washed by adding 50 ml of 2N NaOH and washed with water until neutral. The ethyl acetate solution washed with water is concentrated under reduced pressure,
A solid was precipitated in hexane, filtered and dried in vacuo to give the product.

This product was confirmed to be a resin having a weight average molecular weight (Mw) of 27000 by GPC (using a differential refractive index detector). It was also found that the dissolution rate of the resin in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide was as small as 0.3 nm / sec. (Polymer Synthesis Example 2) Substantially similar results using the compound of Vinyl Ether Synthesis Example 2 in place of the vinyl ether compound of Polymer Synthesis Example 1 described above, that is, the weight average molecular weight (Mw) substantially similar to the above-mentioned weight average molecular weight (Mw) A resin having a molecular weight (Mw) was obtained. (Polymer Synthesis Example 3) Substantially similar results were obtained using 1,4-cyclohexanedimethanol divinyl ether instead of the vinyl ether compound of Polymer Synthesis Example 1 described above. (Polymer Synthesis Example 4) A p-hydroxyhexafluoroisopropylstyrene / styrene copolymer (copolymerization ratio of 1:
Substantially similar results were obtained using 1). (Polymer Synthesis Example 5) A synthesis example of a polymer obtained by subjecting a compound having an alkali-soluble group and a compound having a vinyl ether group to an acid-catalyzed addition reaction will be described.

Polynuclear phenol compound TPPA1000-
2.0 g of P (manufactured by Honshu Chemical Industry Co., Ltd.) (molecular weight: 1060) and 1.0 g of the compound of Vinyl Ether Synthesis Example 1 were dissolved in 100 ml of ethyl acetate. To this was added 0.01 g of pyridinium p-toluenesulfonate,
For 24 hours. Thereafter, the reaction solution was transferred to a separating funnel, 50 ml of 2N NaOH was added, washed, and washed with water until neutral. The ethyl acetate solution washed with water was concentrated under reduced pressure to precipitate a solid in hexane, filtered, and dried under vacuum to obtain a product.

This product was confirmed to be a resin having a weight average molecular weight (Mw) of 7,600 by GPC (using a differential refractive index detector). Further, it was found that the dissolution rate of the resin in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide was as small as 0.1 nm / sec. (Polymer Synthesis Example 6) Instead of the polynuclear phenol compound TPPA1000-P of Polymer Synthesis Example 5 described above, ethylidene tris (4,1-phenyleneoxyacetic acid) (molecular weight: 4)
80) gave substantially the same results. (Polymer Synthesis Example 7) A method similar to Polymer Synthesis Example 5 except that 2.0 g of the polynuclear phenol compound TPPA1000-P described in Polymer Synthesis Example 5 and 0.6 g of the compound described in Vinyl Ether Synthesis Example 1 were used. To synthesize a polymer. The obtained product was found to be a resin having a weight average molecular weight (Mw) of 4200 by GPC (using a differential refractive index detector). The dissolution rate of the resin in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide was 8.5 nm / sec, and the dissolution rate of the resin in a 1.19% by weight aqueous solution of tetramethylammonium hydroxide was used. Was found to be 0.3 nm / sec. Example 1 Resin of Polymer Synthesis Example 1 (Mw: 2700)
0) 100 parts by weight and 5 parts by weight of triphenylsulfonium trifluoromethanesulfonate as a compound capable of generating an acid upon exposure were dissolved in methyl cellosolve acetate to prepare a resist solution having a solid concentration of 10% by weight. The above-mentioned resist is dropped on a silicon wafer, and after spin coating,
Heat treatment was performed at 00 ° C. for 2 minutes to obtain a resist film having a thickness of 0.5 μm. A 500 W Xe-Hg lamp and a 250 nm interference filter (manufactured by Nippon Vacuum Optical Co., Ltd.)
Exposure was performed at an exposure amount of 100 mJ / cm ² and heat treatment was performed at 100 ° C. for 5 minutes. Next, the resist film was dissolved in 1 ml of tetrahydrofuran, and the Mwex of the resin after the acid-catalyzed reaction was determined by GPC. As a result, it was found that Mwex was 1800, which is the same as Mw of the raw material polyvinylphenol. This proved that Mw / Mwex was 15.

Next, the steps up to the formation of a resist pattern will be described. As shown in FIG. 1, 0.025 weight of a polymer obtained by epoxidizing 60% of 1,4-polybutadiene (weight average molecular weight: 3 × 10 ⁵ ) on the surface of a quartz glass substrate 101 having a diameter of 200 mm and a thickness of 6 mm. % Xylene solution
After dropping 4 ml and spin-coating, it was heat-treated at 180 ° C. for 5 minutes and dried to obtain an adhesion improving medium film 102.

On this substrate, the resin 100 of Synthesis Example 1 was used.
4 parts by weight of triphenylsulfonium nonafluorobutanesulfonate as a compound capable of generating an acid upon exposure and 0.1 part by weight of tetraethylphosphonium iodide as an ion dissociating compound are dissolved in 2-heptanone, and the solid concentration is 10% by weight. The resist solution prepared as above was dropped and spin-coated, and then heat-treated at 100 ° C. for 2 minutes.
A positive resist film 103 having a thickness of μm was obtained.

The electron beam 104 was applied to the substrate at a rate of 10 μC /
Irradiation was performed at an irradiation amount of cm ² , and drawing was performed. The drawing pattern has a pit line width of 0.1 μm, a track pitch of 0.2 μm,
Pit lengths were in the range of 0.1 to 0.3 μm, and these were drawn in a spiral. After this, 100
C. for 2 minutes to promote the acid-catalyzed reaction of the latent image forming portion 105. After the heat treatment described above, the resist pattern 106 was obtained by dipping in an aqueous solution containing 2.38% by weight of tetramethylammonium hydroxide for 60 seconds.

As a result, a pattern having a pit line width of 0.1 μm could be resolved with good shape. The line width of the pit was measured at 10 points, and it was found that the difference between the maximum value and the minimum value of the line width (pattern roughness) was 10 nm, indicating that high dimensional accuracy was obtained. (Comparative Example 1): Conventional Example Resin of Polymer Synthesis Example 1 used in Example 1 (Mw:
M / p-cresol novolak resin (Mw: 50) instead of 27000).
00, polydispersity: 1.4) and 1,1,1-tris (4-
Mixture of hydroxyphenyl) ethane (dissolution rate: 40
(nm / sec) 90 parts by weight, poly (p-vinylphenol) having a tetrahydropyranyl group as an acid-decomposable group as a dissolution inhibitor (substitution rate of tetrahydropyranyl group: 0.95,
Mw: 2000, polydispersity: 1.8) A pattern was formed in the same manner as in Example 1, except that a resin composition consisting of 10 parts by weight was used.

As a result, it was found that Mw / Mwex was 1.1. Using this resin, a pit pattern was formed by preparing the same resist composition as in Example 1.
A pit pattern having a width of 1 μm could not be formed. (Comparative Example 2): Conventional Example Resin of Polymer Synthesis Example 1 used in Example 1 (Mw:
Poly (p-vinylphenol) having a 1-ethoxyethyl group as an acid-decomposable group (substitution ratio of 1-ethoxyethyl group: 0.4, Mw: 5000, polydispersity: 1.3). ) Was carried out in the same manner as in Example 1 except that the resin composition of (1) was used. As a result, Mw / Mwex is 1.
It turned out to be 4. A pit pattern was formed by using this resin to prepare the same resist composition as in Example 1, and as a result, the pit pattern having a width of 0.1 μm had a difference between the maximum value and the minimum value of the line width as large as 35 nm, resulting in poor dimensional accuracy. I understood that. Example 2 A pattern was formed in the same manner as in Example 1 except that the resin of Polymer Synthesis Example 2 was used instead of the resin of Polymer Synthesis Example 1, and the same results as in Example 1 were obtained. . Mw / Mwex of the resin used was 15. Example 3 A pattern was formed in the same manner as in Example 1 except that the resin of Polymer Synthesis Example 3 was used instead of the resin of Polymer Synthesis Example 1, and the same results as in Example 1 were obtained. . Mw / Mwex of the resin used was 15. Example 4 A pattern was formed in the same manner as in Example 1 except that the resin of Polymer Synthesis Example 4 was used instead of the resin of Polymer Synthesis Example 1, and the same results as in Example 1 were obtained. . Mw / Mwex of the resin used was 15. Example 5 A pattern was formed in the same manner as in Example 1 except that the resin of Polymer Synthesis Example 5 was used instead of the resin of Polymer Synthesis Example 1, and the same results as in Example 1 were obtained. . Mw / Mwex of the used resin was 7. Example 6 A pattern was formed in the same manner as in Example 1 except that the resin of Polymer Synthesis Example 6 was used instead of the resin of Polymer Synthesis Example 1, and the same results as in Example 1 were obtained. . Mw / Mwex of the resin used was 16. (Example 7) The procedure of Example 1 was repeated, except that the resin of Polymer Synthesis Example 7 was used instead of the resin of Polymer Synthesis Example 1. As a result, Mwex is 1620 and Mw
/ Mwex was found to be 2.6. Using this resin, a resist composition similar to that of Example 1 was prepared, and a pit pattern was formed using a 1.19% by weight aqueous solution of tetramethylammonium hydroxide as a developing solution. As a result, the same result as that of Example 1 was obtained. Was. (Embodiment 8) Using an electron beam drawing technique, a ROM (Rea
An embodiment in which the present invention is applied to a process of manufacturing a stamper of the (d Only Memory) type will be described.

First, after the surface of the quartz substrate was treated with the adhesion improver used in Example 1, the resist composition used in Example 5 was spin-coated on the substrate and heat-treated at 100 ° C. for 2 minutes. Then, a resist film having a thickness of 0.2 μm was obtained. Next, an antistatic film spacer 300 is formed on the resist film.
(Showa Denko Co., Ltd.) spin-coated and heat-treated for 10
Dried for minutes.

The above-mentioned substrate was treated with an electron beam lithography apparatus (acceleration voltage 30).
kV), the resist film is irradiated with an electron beam while the electron beam is sent from the inner peripheral side of the substrate to the outer peripheral side at a track pitch of 200 nm, and the pit is formed on the spiral track. A latent image was formed. This board is
After heat treatment at 00 ° C. for 2 minutes, the resist pattern was immersed in an aqueous solution containing 2.38% by weight of tetramethylammonium hydroxide for 60 seconds to obtain a resist pattern.

Using this resist film as a mask, the quartz substrate is dry-etched to a depth of 30 nm to 70 nm by reactive ion etching with a mixed gas of C ₂ F ₆ and H ₂ to form a predetermined concave pit pattern. An optical disc master was obtained.

Hereinafter, as usual, aluminum is vapor-deposited on the concave pattern surface of the optical disk master, and then a plating layer is formed on the aluminum vapor-deposited film by electroplating. A mother was manufactured from the metal master obtained by peeling off the part, and a stamper was manufactured from the mother. As a result, a stamper with high density and good dimensional accuracy could be obtained.

It is to be noted that a stamper with high density and high dimensional accuracy can be obtained by using the resist composition used in Examples 1 to 4, 6, and 7 instead of the resist composition used in Example 5. Was.

[0044]

According to the present invention, a pit pattern having high sensitivity and excellent resolution with respect to radiation such as electron beams and X-rays can be formed, and a stamper having high density and high dimensional accuracy can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a part of a manufacturing process of an optical disc master according to an embodiment of the present invention.

[Explanation of symbols]

101: quartz substrate, 102: adhesion-improving medium film, 103
.., A positive resist film, 104, an electron beam, 105, a latent image forming portion, 106, a resist pattern.

Continued on the front page F-term (reference) 2H025 AA00 AA01 AA02 AB17 AC04 AC05 AC06 AD03 BE00 BG00 BJ04 BJ05 FA03 FA12 FA17 FA41 2H096 AA00 AA27 BA11 BA20 EA03 EA06 EA07 FA01 GA08 HA23 JA04 LA17 5D121 BB03 BB01 BB21

Claims (1)

[Claims] A latent image is formed on a coating film of a resist composition applied on a substrate by exposure or exposure and heat treatment after exposure, and is developed with an aqueous alkaline developer to form a resist pattern. In the method for producing a stamper, the method includes a step of forming a concave portion in the substrate using a pattern as a mask, wherein the resist composition comprises (a) a compound which generates an acid upon exposure, (b) exposure or heat treatment after exposure and exposure. And a weight-average molecular weight (Mw) of the medium, and a weight-average molecular weight after the reaction induced by exposure or heat treatment after exposure and exposure. A method for producing a stamper, wherein the medium has a ratio (Mw / Mwex) of 2 or more to (Mwex).