JPH0470662A - Siloxane polymer and resist composition - Google Patents

Abstract

PURPOSE:To obtain a higher glass transition temp. and to improve oxygen plasma resistance by protecting a part or the whole of the hydroxyl group of specific polysiloxane with an alkyl group, substd. alkyl group, arom. group or silyl group. CONSTITUTION:The chemical structure of a ladder type which adopts the siloxane bond as a skeletal structure and uses the multifunctional alkoxysilane as a raw material is adopted in such a manner and the hydroxyl group subjected to ring opening by the introduction of the oxysilane ring is protected by the suitable functional groups, by which alkaline development is enabled. The higher glass transition temp. is obtd. in this way and the oxygen plasma resistance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resist composition for high-energy radiation that reproduces a positive pattern with high precision and has high resistance to oxygen plasma.

[Conventional technology]

Positive-type photoresists made of novolak resin and naphthoquinonediazide as a photosensitizer have recently been used in the field of lithography because they have characteristics such as high sensitivity, high resolution, and alkali solubility. Now, two-layer Gist CB,
J, Lin (B, J.

Lin), Solid State Technology (Sol
id 5tate Technol, Vol. 24, p. 73 (1981)], a pattern with a high shape ratio is anisotropically etched using oxygen plasma etching (O□RIB) using a resist thin film formed on a substrate as a mask. It is obtained by This 0□RIB resistance has become extremely important for resist materials. Materials that form oxides by RIH, generally materials containing silicon, are said to have excellent O□RIB resistance. However, current photoresists do not contain silicon components and therefore have a 0□RIB
It had the disadvantage of poor tolerance. To solve this problem, polysiloxane-based resist materials have been proposed, but this type of material generally has a low glass transition temperature, so it is easy to get dust during processing, it is difficult to control the film thickness, and it is difficult to control the film thickness during development. There were major problems in compatibility with the process, such as deterioration in developability due to deformation.

[Problem to be solved by the invention]

Therefore, the glass transition temperature is high, and 0, RIB
Resist materials with excellent resistance and alkaline development are expected.

An object of the present invention is to provide a siloxane polymer and a resist composition that solve the above problems.

[Means to solve the problem]

To summarize the present invention, the first invention of the present invention relates to a siloxane polymer, in which a part or all of the hydroxyl groups of a polysiloxane obtained by hydrolysis and condensation of an alkoxysilane having an oxirane ring are replaced with an alkyl group, It is characterized by being protected with a substituted alkyl group, aromatic group, or silyl group.

The second invention of the present invention relates to a resist composition, and is characterized in that it contains the siloxane polymer of the first invention and an acid generator.

In order to solve the above-mentioned problems, the present invention first improves the 02RIE resistance by using siloxane bonds as a skeleton structure, and by creating a ladder-type chemical structure using polyfunctional alkoxysilane as a raw material. Alkaline development becomes possible by increasing the transition temperature, introducing an oxirane ring, and protecting the hydroxyl group opened by the ring with an appropriate functional group.

The siloxane polymer of the present invention is generally synthesized by the following method. First, a specific alkoxysilane is dissolved in alcohol such as ethanol, and water and a catalyst such as hydrochloric acid are added to this. This catalyst may optionally be omitted.

This reaction proceeds at room temperature, but may be heated if necessary. After a predetermined period of time has elapsed, the reaction solution is poured into water, and the precipitated product is filtered out and then dried. The product at this stage may be used for practical purposes, or if a higher polymer is desired, the product may be further reacted with an alkali catalyst in an appropriate solvent. Alternatively, it is also effective to proceed with condensation by further heating in bulk. In these reaction processes, the oxirane ring opens and changes into a corresponding hydroxyl group, which dissolves in an aqueous alkaline solution. By protecting some or all of the hydroxyl groups of this polysiloxane with an appropriate functional group, a siloxane polymer that is sparingly soluble in aqueous alkaline solutions can be obtained.

Furthermore, since the polysiloxane obtained by hydrolysis and condensation of the alkoxysilane of the present invention generally has a silanol group at the end, there is a possibility that this condensation may cause the properties to change over time. To avoid this, the silanol group can be replaced by another non-reactive substituent using a silylating agent.

The alkoxysilane having an oxirane ring used in the present invention is not particularly limited, and is a bifunctional or trifunctional alkoxysilane having an oxirane ring in the molecule. Specifically, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-(N-allyl-
N-glycidyl)aminopropyltrimethoxysilane,
3-(N,N-diglycidyl)aminopropyltrimethoxysilane, N-glycidyl-N,N-bis[3-(
methyldimethoxysilyl)propyl]amine, N-glycidyl-N,N-bis-[3-()rimethoxysilyl)
propyl]amine, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyljethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(N-allyl-N- glycidyl)aminopropyltriethoxysilane, 3-(N
, N-diglycidyl)aminopropyltriethoxysilane, N-glycidyl-N, N-bis[3-(methyljethoxysilyl)propyl]amine, N-glycidyl-N, N-bis[3-()ethoxysilane ) propyl] amine and the like.

The present invention also includes polysiloxanes obtained by copolymerizing an alkoxysilane having an oxirane ring with a general-purpose metal alkoxide or metal chloride. Although this type of general-purpose metal alkoxide is not particularly limited, the following are exemplified. Dimethoxydimethylsilane, jetoxydimethylsilane, dimethoxymethyl-3,3,3-trifluoropropylsilane, jetoxyvinylsilane, jetoxydiethylsilane, 3-
Aminopropyljethoxymethylsilane, 3- (2-
Aminoethylamino)propyldimethoxymethylsilane, dimethoxymethylphenylsilane, jetoxymethylphenylsilane, dimethoxydiphenylsilane, jetoxydiphenylsilane, tris-(2-methoxyethoxy)vinylsilane, methyltrimethoxysilane, ethyltrimethoxysilane, 3 ,3.3-)lifluoropropyltrimethoxysilane, methyltriethoxysilane, 3
-(N-methylamino)propyltrimethoxysilane,
Methyltris-(2-γminoethoxy)silane, triacetoxyvinylsilane, triethoxyvinylsilane, ethyltriethoxysilane, 3-mercaptopropyltriethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, phenyltrimethoxysilane, 2-cyanoethyltriethoxysilane, allyltriethoxysilane, propyltriethoxysilane, hexyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, methyltripropoxysilane, phenyltriethoxysilane, 3 -[N-allyl-N-(2-aminoethyl)]aminopropyltrimethoxysilane, 4-trimethoxysilyltetrahydrophthalic anhydride, 4-triethoxysilyltetrahydrophthalic anhydride, 4-triisopropoxysilyltetrahydro Phthalic anhydride, 4-trimethoxysilyltetrahydrophthalic acid, 4-triethoxysilyltetrahydrophthalic acid, 4-triisopropoxysilyltetrahydrophthalic acid, tetramethoxysilane, tetraethoxysilane, tetrabutoxytitanium, tetraethoxyzircon, tetra butoxyzircon, tetraisopropoxyzircon, tetramethoxygermane,
Tetraethoxytitanium, tetrabutoxytitanium, tetrabutoxytin, pentabutoxyniobium, pentabutoxytalium, triethoxypolone, tributoxygallium, dibutoxylead, tributoxyneodymium, tributoxyerbium. Among these, phenyltriethoxysilane, methyltriethoxysilane and tetraethoxysilane are particularly preferred from the viewpoint of raw material availability, reactivity, properties of the obtained product, etc. Examples of metal chlorides include n-butyltrichlorosilane, dimethyldichlorosilane, ethyltrichlorosilane, methyltrichlorosilane, phenyltrichlorosilane, trichlorovinylsilane, diphenyldichlorosilane, and the like.

The siloxane polymer of the present invention is 248nm with a thickness of 1μm.
The light transmittance at m is 90% or more, and even when phenyltriethoxysilane is copolymerized, it is 70% or more, making it promising as a resist for excimer lasers.

The catalyst used in the present invention is not particularly limited, and acid catalysts and alkali catalysts are used. Such acid catalysts include hydrochloric acid, hydrofluoric acid, nitric acid, sulfuric acid,
Examples include acetic acid and formic acid. Furthermore, examples of the alkali catalyst include ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide, and the like.

The siloxane polymer of the first invention can be applied to various uses in combination with a suitable acid generator.

The second invention of the present invention is one of such combinations,
Siloxane polymers are poorly soluble in alkaline aqueous solutions because some or all of the hydroxyl groups are protected, but the protective groups can be removed using the acid generated from the acid generator as a catalyst when irradiated with high-energy beams such as electron beams. A dissociation reaction occurs and it changes to an alkali-soluble hydroxyl group. That is, when the resist composition of the present invention is irradiated with high-energy rays, the protective groups of the siloxane polymer in the irradiated areas are removed and become corresponding hydroxyl groups, and the irradiated areas are removed by alkaline development, so that they exhibit positive resist properties.

In this resist composition, the acid generator also serves as an agent for preventing the siloxane polymer from dissolving in the alkaline solution. The amount of acid generator added is usually in the range of 0.5 to 20% by weight, and if it is less than 0.5%, the amount of acid generated is small. This makes it difficult to achieve high sensitivity. Moreover, if it exceeds 20%, the silicon content as a resist material decreases, and the oxygen plasma resistance decreases. Further, there is a problem that absorption at 248 nm becomes large. Generally, a preferable addition amount is about 5%.

The acid generator in the present invention is not particularly limited, but includes the following:
) Ar21'MXn-(n) Ar2S"MXn-(m) (wherein MXn represents one selected from the group of BF, PF, Ash and SbF6) or methyl halide Triazine, tetrabromobisphenol A1 nitrobenzyl ester, etc. can be used.Some acid generators have low sensitivity to ultraviolet rays with a wavelength of 300 nm or more, but in that case, a spectral sensitizer such as phenothiazine may be used. It is also possible to add.

Next, an example of a method for forming a pattern using the resist composition of the present invention will be described. First, a film of an organic polymer material is formed on a substrate such as silicon, and the resist composition of the present invention is applied thereon to form a two-layer structure. Next, after heat treatment and irradiation with high energy rays, the irradiated area is made soluble in an alkaline aqueous solution by heat treatment, and then the resist composition in the irradiated area is removed by alkaline development. next,
Using the resist composition in the non-irradiated area as a mask, a pattern is formed by dry etching using oxygen gas to remove the underlying organic polymer film.

The above-mentioned organic polymer material may be of any type as long as it can be etched by oxygen plasma, but after pattern formation, when dry etching the substrate using this as a mask, resistance is required, so Group-containing polymers are preferred.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to synthesis examples and examples of the siloxane polymer of the present invention, but the present invention is not limited to these aspects.

Examples of synthesis of siloxane polymers are shown below.

Synthesis example 1 3-glycidoxypropyltrimethoxysilane 23.6
g (0.1 mol) was dissolved in ethanol, and an aqueous hydrochloric acid solution was added thereto with stirring.

After reacting at room temperature for 24 hours, 14444 was further heated at 60°C.
It took time to react. After cooling to room temperature, add ammonia and further cool for 24 hours.
The reaction continued for hours. After the reaction, the reaction solution was poured into distilled water, and the generated precipitate was filtered off to obtain a white polymer. The product is tetrahydrofuran (THF) ethanol,
Ethylene glycol monoethyl ether (ethyl cellosolve) Methyl isobutyl ketone (M I BK) Soluble in solvents such as acetone. Clear, uniform films were obtained from these solutions. Weight average molecular weight is approximately 1000
Met. 3400 cm in infrared absorption spectrum
Absorption based on the stretching vibration of the OH group (hydroxyl group) was observed near -', and it was confirmed that the epoxy group was ring-opened during the reaction process. A siloxane polymer protected with a tert-butoxycarbonyl group was obtained by reacting this with di-tert-butyl dicarbonate using pyridine as a catalyst. By protecting it, the absorption of hydroxyl group became smaller.

Light transmittance at 248 nm is 92% (1 μm thickness)
Met.

Synthesis example 2 3-glycidoxyprobyltrimethoxysilane 11.8
g (0.05 mol) and Hyphenyltriethoxysilane 1
2. Og (0.05 mol) was dissolved in ethanol and an aqueous hydrochloric acid solution was added thereto with stirring. 24 at room temperature
After reacting for an hour, the reaction was further carried out at 60° C. for 144 hours. After the reaction, the reaction solution was poured into distilled water, and the generated precipitate was filtered off to obtain a white polymer. The product was soluble in solvents such as THF, ethanol, ethyl cellosolve, MIBK, acetone, and ethyl acetate.

Clear, uniform films were obtained from these solutions.

This polysiloxane was protected with a tertiary butoxycarbonyl group in the same manner as in Synthesis Example 1 to obtain a poorly alkali-soluble siloxane polymer.

Light transmittance at 248 nm is 75% (1 μm thickness)
Met.

Synthesis example 3 3-glycidoxypropyltrimethoxysilane 11.8
g (0.05 mol) and methyltriethoxysilane8.
9 g (0.05 mol) was dissolved in ethanol, and an aqueous hydrochloric acid solution was added thereto while stirring. After reacting at room temperature for 24 hours, the reaction was further carried out at 60° C. for 144 hours. After the reaction, the reaction solution was poured into distilled water, and the generated precipitate was filtered off to obtain a white polymer. The product was soluble in solvents such as THF, ethanol, ethyl cellosolve, MIBK, acetone, and ethyl acetate. Clear, uniform films were obtained from these solutions.

This was protected with a tertiary butoxycarbonyl group in the same manner as in Synthesis Example 1 to obtain a poorly alkali-soluble siloxane polymer. The light transmittance at 248 nm is 94% (
1 μm thick).

Synthesis example 4 3-glycidoxypropyltrimethoxysilane 4.72
g (0.02 mol) methyltriethoxysilane 8.9
g (0.05 mol) and tetraethoxysilane 6.24
g (0.03 mol) was dissolved in ethanol, and an aqueous hydrochloric acid solution was added thereto with stirring. After reacting at room temperature for 6 hours, ammonia water was added and the reaction was further carried out at 60°C for 24 hours. After the reaction, the reaction solution was poured into distilled water, and the generated precipitate was filtered off to obtain a white polymer.

The weight average molecular weight was 5,000. The product is THF,
Ethanol, ethyl cellosolve, MIBK, acetone,
It was soluble in solvents such as ethyl acetate. Clear, uniform films were obtained from these solutions. This was protected with a tertiary butoxycarbonyl group in the same manner as in Synthesis Example 1 to obtain a poorly alkali-soluble siloxane polymer. The light transmittance at 248 nm was 90% (1 μm thickness).

Synthesis Example 5 24.6 g (0.1 mol) of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane was dissolved in ethanol, and an aqueous hydrochloric acid solution was added thereto while stirring. After reacting at room temperature for 24 hours, it was further reacted at 60° C. for 144 hours.

After the reaction, the reaction solution was poured into distilled water, and the generated precipitate was filtered off to obtain a white polymer. The product was soluble in solvents such as THF, ethanol, ethyl cellosolve, MIBK, and acetone.

Clear, uniform films were obtained from these solutions.

This was protected with a tertiary butoxycarbonyl group in the same manner as in Synthesis Example 1 to obtain a poorly alkali-soluble siloxane polymer. The light transmittance at 248 nm is 90% (1
(μm thickness).

Synthesis Example 6 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane 12.3g (0.05 mol) and phenyltriethoxysilane 12. Og (0.05 mol) was dissolved in ethanol and an aqueous hydrochloric acid solution was added thereto with stirring. After reacting at room temperature for 24 hours, an additional 60
The reaction was carried out at ℃ for 144 hours. After the reaction, the reaction solution was poured into distilled water, and the generated precipitate was filtered off to obtain a white polymer. The products are THF, ethanol, ethyl cellosolve,
It was soluble in solvents such as MIBK, acetone, and ethyl acetate. Clear, uniform films were obtained from these solutions. This was protected with a tertiary butoxycarbonyl group in the same manner as in Synthesis Example 1 to obtain a poorly alkali-soluble siloxane polymer. The light transmittance at 248 nm is 74% (1μ
m thickness).

Synthesis Example 7 12.3 g (0.05 mol) of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 8.9 g (0.05 mol) of methyltriethoxysilane were dissolved in ethanol and dissolved while stirring. To this was added an aqueous hydrochloric acid solution. After reacting at room temperature for 24 hours, further react at 60℃1
The reaction was allowed to proceed for 44 hours. After the reaction, the reaction solution was poured into distilled water, and the generated precipitate was filtered off to obtain a white polymer.

The products are THF, ethanol, ethyl cellosolve, MI
It was soluble in solvents such as BK, acetone, and ethyl acetate.

Clear, uniform films were obtained from these solutions. This was KN-retained with a tertiary butoxycarbonyl group in the same manner as in Synthesis Example 1 to obtain a poorly alkali-soluble siloxane polymer.

The light transmittance at 248 nm was 94% (1 μm thickness).

Synthesis Example 8 2-(3,4-epoxycyclohexyl)dityltrimethoxysilane 4.92 g (0.02 mol) methyltriethoxysilane 8.9 g (0.05 mol) and tetraethoxysilane 6.24 g ( 0.03 mol) was dissolved in ethanol, and an aqueous hydrochloric acid solution was added thereto while stirring. After reacting at room temperature for 6 hours, ammonia water was added and the reaction was further carried out at 60°C for 24 hours. After cooling to room temperature,
Ammonia was added and the reaction was continued for an additional 12 hours. After the reaction, the reaction solution was poured into distilled water, and the generated precipitate was filtered off to obtain a white polymer. The product was soluble in solvents such as THF, ethanol, ethyl cellosolve, MIBK, acetone, and ethyl acetate.

Clear, uniform films were obtained from these solutions.

This was protected with a tertiary butoxycarbonyl group in the same manner as in Synthesis Example 1 to obtain a poorly alkali-soluble siloxane polymer. The light transmittance at 248 nm is 94% (1
(μm thickness).

Synthesis Example 9 4.92 g (0.02 mol) of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 19.2 g (0.08 mol) of phenyltriethoxysilane were dissolved in ethanol and stirred. At the same time, an aqueous hydrochloric acid solution was added thereto. After reacting at room temperature for 24 hours, it was further reacted at 60° C. for 144 hours. After the reaction, the reaction solution was poured into distilled water, and the generated precipitate was filtered off to obtain a white polymer.

The products are THF, ethanol, ethyl cellosolve, MI
It was soluble in solvents such as BK, acetone, and ethyl acetate.

Clear, uniform films were obtained from these solutions. This was protected with a tertiary butoxycarbonyl group in the same manner as in Synthesis Example 1 to obtain a poorly alkali-soluble siloxane polymer.

Light transmittance at 248 nm is 74% (1 μm thickness)
Met.

Synthesis Example 10 4.92 g (0.02 mol) of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 14.2 g (0.08 mol) of methyltriethoxysilane were dissolved in ethanol and dissolved while stirring. To this was added an aqueous hydrochloric acid solution. After reacting at room temperature for 24 hours, further react at 60℃
The reaction was carried out for 144 hours. After the reaction, the reaction solution was poured into distilled water, and the generated precipitate was filtered off to obtain a white polymer.

The products are THF, ethanol, ethyl cellosolve, MI
It was soluble in solvents such as BK, acetone, and ethyl acetate.

Clear, uniform films were obtained from these solutions. This was protected with a tertiary butoxycarbonyl group in the same manner as in Synthesis Example 1 to obtain a poorly alkali-soluble siloxane polymer.

Light transmittance at 248 nm is 92% (1 μm thickness)
Met.

Synthesis Example 11 A siloxane polymer was obtained as tertiary butyl ether by reacting the hydroxyl group of the polysiloxane synthesized in Synthesis Example 1 with isobutylene using para-toluenesulfonic acid as a catalyst. The light transmittance at 248 nm was 90% (1 μm thickness).

Synthesis Example 12 The hydroxyl group of the polysiloxane synthesized in Synthesis Example 1 was reacted with 2,3-dihydro-4H-pyran using para-toluenesulfonic acid as a catalyst, to obtain a siloxane polymer as tetrahydropyranyl ether. 2
The light transmittance at 48 nm was 89% (1 μm thickness).

Synthesis Example 13 The hydroxyl groups of the polysiloxane synthesized in Synthesis Example 1 were reacted with acetaldehyde using para-toluenesulfonic acid as a catalyst, to obtain a siloxane polymer in the form of acetal.

Light transmittance at 248 nm is 92% (1 μm thickness)
Met.

Synthesis Example 14 A silylated siloxane polymer was obtained by reacting the hydroxyl group of the polysiloxane synthesized in Synthesis Example 1 with trimethylchlorosilane using pyridine as a catalyst. The light transmittance at 248 nm was 94% (1 μm thickness).

Examples will be described below, but the present invention is not limited thereto.

Example 1 A resist composition prepared by adding 10% by weight of 2,6-sinitropendyl tosylate to the siloxane polymer obtained in Synthesis Examples 1 to 14 was applied to a silicon wafer at a thickness of about 0.3 μW by a spin cord method. , prebaked at 80°C for 20 minutes. After prebaking, high energy beams (electron beams, X-rays, far ultraviolet rays) were irradiated. After irradiation, heat treatment was performed on a 110°C hot plate for 5 minutes, followed by Microposite 240
1 (manufactured by Sibley) and water in a developer solution with a ratio of 1:1. was taken as the sensitivity.

Table 1 shows the sensitivity and resolution. The resolution was evaluated by forming a line & space pattern, and the resolution was 0.3 μm for each material.
The following pattern was formed.

Example 2 A resist composition prepared by adding 0.5% by weight of phenothiazine as a spectral sensitizer to the polymer to the resist composition of Example 1 was applied to a silicon wafer to a thickness of about 0.3 μm, and heated at 80°C. Prebaked for 20 minutes. After prebaking, ultraviolet rays were irradiated using a mask aligner (manufactured by Canon).

After irradiation, heat treatment was performed in the same manner as in Example 1, followed by development with the same developer, and the sensitivity was determined as the irradiation amount at which the remaining film in the irradiated area was 0.

Table 2 shows the sensitivity and resolution. The resolution was evaluated by forming a line & space pattern, and the resolution was 0.5 μm for each material.
A wide pattern was formed.

Example 3 Z-1350 resist (manufactured by Hegyusto Co., Ltd.) was applied to a silicon wafer to a thickness of 3 μm, and heated at 200° C. for 30 minutes to insolubilize it. On this AZ resist, apply the resist composition used in Example 1 or Example 2 to a thickness of about 0.3 μm.
The coating was applied to a thickness of 100.degree. C. and prebaked at 80.degree. C. for 20 minutes. After pre-beta, it is irradiated with high-energy rays (electron beam, X-ray, far ultraviolet rays in the case of Example 1, ultraviolet rays in the case of Example 2), and heat treated in the same manner as in Example 1 or Example 2. Subsequently, development was performed with a developer having the same composition to form a pattern. Thereafter, the AZ resist was etched using a parallel plate type sputter etching apparatus using oxygen gas as an etching gas and using the above resist pattern as a mask.

By etching for 15 minutes under the conditions of RF power of 0.2 W/cm' and O2 gas pressure of 20 mTorr, the AZ resist in the portions not covered by the resist pattern was completely eliminated.

Furthermore, any of the resist compositions used in Example 1 had 0
．． A 3 μm line and space pattern can be formed with a thickness of about 3 μm, and when the composition of Example 2 is used, it is 0.5 μm thick.
A line and space pattern was formed.

Example 4 A resist composition was prepared by adding the following acid generator to the siloxane polymer obtained in Synthesis Example 1, and the resist properties were evaluated in the same manner as in Example 1. The results are shown in Table 3.

〔Effect of the invention〕

As explained above, the siloxane polymer of the present invention is
By protecting the hydroxyl groups of an alkali-soluble polysiloxane with an appropriate functional group, it is made poorly alkali-soluble. In addition, a resist composition containing an acid generator that generates acid when irradiated with high-energy rays uses the acid as a catalyst to remove the protective group and change to the original hydroxyl group, resulting in a non-swellable positive resist that can be developed with alkali. .

Furthermore, since it contains silicon, it has high resistance to oxygen plasma, and therefore can be used as an upper layer resist of a two-layer resist. Since it can be used in a two-layer resist, it has the advantage that fine patterns of 0.5 μm or less can be formed with a high aspect ratio.

Patent applicant: Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. Part or all of the hydroxyl groups of a polysiloxane obtained by hydrolysis/condensation of an alkoxysilane having an oxirane ring are protected with an alkyl group, a substituted alkyl group, an aromatic group, or a silyl group. A siloxane polymer characterized by: 2. A resist composition comprising the siloxane polymer according to claim 1 and an acid generator.