JPH08160620A - Positivee type resist material - Google Patents

Abstract

PURPOSE: To provide a positive type resist material sensitive to high-energy beams and excellent in sensitivity and resolution. CONSTITUTION: This positive type resist material can be developed by an alkaline aqueous solution containing two components of a silicone polymer expressed by formula I and an acid generating agent decomposed by the action of the illuminated radioactive rays to generate acid. The acid generating agent is the onium salt expressed by formula II (R)PJM. In formula I, Q indicates the t-butoxy carbonyl group, (n) indicates an integer of 1-3, x+m=1, and (x) is non-zero. In formula II, R is the aromatic group or substituted aromatic group, at least one of R is the phenyl group substituted with the t-alkoxy group expressed by R<1> 3 CO- (R<1> is the substituted or unsubstituted monovalent hydrocarbon group), J indicates sulfonium or iodonium, M indicates the p-toluene sulfonate group or trifluoromethane sulfonate group, and (p) is 2 or 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
It has high sensitivity to high energy rays such as rays and can form a pattern by developing with an alkaline aqueous solution.
The present invention relates to a positive resist material suitable for fine processing technology.

[0002]

2. Description of the Related Art LSI to be Solved
Along with the high integration and high speed of chemicals, recently developed acid has been used as a catalyst for chemical amplification.
resist material [eg Liu (L
iu), etc., Journal of Vacuum Science and Technology (J. Vac. Sci. Tech.
nol. ), B6, 379 (1988)],
It has excellent characteristics that it has sensitivity equal to or higher than that of conventional high-sensitivity resist material, high resolution, and high dry etching resistance. Therefore, it is a particularly promising resist material for deep ultraviolet lithography. However, as a negative resist, Shipley has already commercialized a three-component chemically amplified resist material (trade name SAL601ER7) consisting of a novolak resin, a melamine compound and an acid generator, but it is a chemically amplified positive type resist. No resist material has been commercialized yet. Therefore, in the manufacturing process of the LSI, the negative resist material can be used for wiring and gate formation, but the contact hole formation is difficult to perform fine processing because a negative resist material is used. There has been a strong demand for a positive resist material. Conventionally, Ito et al. Developed a positive chemically amplified resist material by adding an onium salt to a resin called PBOCST in which an OH group of polyhydroxystyrene is protected by a t-butoxycarbonyl group (t-BOC group). ing.

However, the onium salt used contains antimony as a metal component [Reference: Polymers in Electronics, ACS Symposium Series (Polymers in Electro).
nics, ACS symposium Series
s) 242nd (American Chemical Society, Washington DC.
1984), p. 11], the PBOCST resist material is not preferable in the process from the viewpoint of preventing contamination of the substrate.

On the other hand, Ueno et al. Have announced a deep UV chemical amplification type positive resist material containing poly (p-styreneoxytetrahydropyranyl) as a main component and having high sensitivity and high resolution (reference: No. 1). The 36th Joint Lecture Meeting of Japan Society of Applied Physics, 1989, 1p-k-7), it was difficult to form a fine pattern having a high aspect ratio with high precision because of the mechanical strength of the pattern.

As described above, a number of chemically amplified positive resist materials based on novolac resins and polyhydroxystyrene, which are sensitive to deep ultraviolet rays, electron beams and X-rays, have been hitherto announced. All of them are single-layer resists, and there are still problems with substrate steps, problems with standing waves due to light reflection from the substrate, and problems with pattern formation with high aspect ratios. .

By the way, the two-layer resist method is excellent for forming a pattern having a high aspect ratio on a stepped substrate.
A silicone-based polymer having a hydrophilic group such as a hydroxy group or a carboxyl group is required for alkali development by the two-layer resist method, and silanol having a hydroxy group directly attached to the silicone causes a crosslinking reaction with an acid. Therefore, it has been difficult to apply it to a chemically amplified positive resist material. Polyhydroxybenzylsilsesquioxane is a stable alkali-soluble silicone polymer, and a material in which a part of the hydroxy group is protected by t-BOC is a chemically amplified silicone positive type in combination with an acid generator. It is known to be used as a resist material (JP-A-6-118651 or SPIE Vo).
l. 1925 (1993) 377).

However, since the silicone polymer has poor compatibility with the acid generator, there is a problem that a fine pattern cannot be formed.

[0008] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a chemically amplified silicone-based positive resist material which is suitable as a two-layer resist material and has high sensitivity, high resolution, and excellent process applicability.

[0009]

The inventor of the present invention has
As a result of earnest study to achieve the above purpose, the above general
Silicone polymer represented by formula (1) and acid generator
And, if necessary, a dissolution inhibitor as a main component
In the dist material, the following general formula (2) (R )_pJM (2) (In the formula, R Is an aromatic group or a substituted aromatic group,
At least one is R¹ ₃CO- (R¹Has 1 to 10 carbon atoms
Represents a substituted or unsubstituted monovalent hydrocarbon group)
-Alkoxy group, t-butoxycarbonyloxy group or
Phenyl substituted with t-butoxycarbonylmethoxy group
Is a sulfonyl group and J is sulfonium or iodonium.
And M is a p-toluene sulfonate group or trifluoro
Indicates a methanesulfonate group. p is 2 or 3
It The use of an onium salt represented by
Effective as a resist material using corn polymer
I found that.

That is, as an onium salt of trifluoromethane sulfonate or toluene sulfonate,
Compounds represented by the following formulas (a) to (f) are known.

[0011]

Embedded image

However, since any of these acid generators has any of the following drawbacks, the performance as a resist material is deteriorated. That is, these onium salts have low solubility in a solvent suitable for coating a resist material such as ethyl cellosolve acetate, ethyl lactate, and ethoxy-2-propanol. Therefore, it is difficult to mix an appropriate amount in the resist material. Further, even if it has a high solubility in a solvent, it is difficult to form a good resist film due to its poor compatibility with a silicone polymer, and it is necessary to perform heat treatment after light irradiation. That is, a change in sensitivity and a change in pattern shape with time are likely to occur. Particularly in the case of an acid generator having poor compatibility, distribution may occur in the resist film and an overhang may be observed on the pattern surface. In the chemically amplified resist material, the acid is deactivated on the resist film surface,
Alternatively, such a phenomenon often occurs when the surface is free of the acid generator.

Further, the trifluoromethanesulfonate-based onium salts (c) and (e) are effective, but there is a problem that the pattern cross-sectional shape becomes an inverse taper. On the contrary, the toluene sulfonate-based onium salt (f) tends to have a forward taper, and when two onium salts of trifluoromethane phosphate and toluene sulfate are mixed and used, the pattern shape is a pattern perpendicular to the substrate. can get. Good properties cannot be obtained unless two onium salts having different properties are mixed (JP-A-6-11).
8651 publication).

Therefore, as a result of extensive studies on the acid generator, the onium salt represented by the general formula (2) was used as the acid generator in a chemically amplified silicone positive resist composition in which a silicone polymer and an acid generator were combined. In the meantime, they found that the drawbacks of conventional silicone-based resist materials can be solved. The onium salt of the present invention has not only good compatibility with a silicone polymer but also excellent solubility after exposure, and a pattern can be formed perpendicular to a substrate. When at least one R in the general formula (2) is a t-alkoxyphenyl group or a t-butoxycarbonyloxyphenyl group, a phenolic hydroxyl group is generated during exposure and heat treatment, so that the solubility is improved. Alternatively, when at least one of Rs in the general formula (2) is a t-butoxycarbonylmethoxyphenyl group, a carboxylic acid is generated during exposure and heat treatment, and thus the solubility is also improved. Generally, an onium salt has a dissolution inhibiting effect, but the onium salt of the present invention has a dissolution promoting effect after exposure. Therefore, the difference in the dissolution rate before and after the exposure can be increased, so that the onium salt of the present invention can accurately form a fine pattern by itself without using a mixed system.

Therefore, the present invention comprises two components, a silicone polymer represented by the following general formula (1) and an acid generator that decomposes to generate an acid by the action of irradiation radiation, and if necessary, a dissolution inhibitor. A positive resist material developable with an alkaline aqueous solution containing, wherein the acid generator is an onium salt represented by the general formula (2).

[0016]

Embedded image (In the formula, Q represents a t-butoxycarbonyl group, a t-butoxycarbonylmethyl group, a trimethylsilyl group or a tetrahydropyranyl group. N is an integer of 1 to 3, x and m are x.
Although + m = 1, x never becomes 0. )

The present invention will be described in more detail below. The polymer used in the positive resist composition of the present invention is
It is a silicone polymer represented by the following general formula (1).

[0018]

[Chemical 4]

Here, Q is a t-butoxycarbonyl group,
A t-butoxycarbonylmethyl group, a trimethylsilyl group or a tetrahydropyranyl group is shown. n shows the integer of 1-3. Further, x and m are x + m = 1, but x is a positive number of 0, and m is 0 or a positive number of m> 0. However, when x in the formula is small, the effect of inhibiting dissolution is small, so that it becomes necessary to add an inhibitor. As x increases, the alkali solubility of the polymer decreases,
Inhibitors are no longer needed. x is preferably 0.05 to 0.5. If it is less than 0.05, the dissolution inhibiting effect is small, and if it is more than 0.5, the oxygen plasma etching resistance may be reduced due to the decrease in the silicone content. Moreover, 0.5
If it is larger than the above range, the solubility in an alkaline aqueous solution is extremely lowered, so that the sensitivity of a commonly used developer may be extremely lowered.

The weight average molecular weight of the silicone polymer used in the present invention is preferably 5,000 to 50,000. If it is less than 5,000, the desired plasma resistance may not be obtained, or the dissolution inhibiting effect in an alkaline aqueous solution may be low. If it is higher than 50,000, it may be difficult to dissolve in a general-purpose resist solvent. There is.

The t-group of the OH group of hydroxybenzyl is
BOC formation is a method of protecting functional groups that is often used in peptide synthesis, and can be easily performed by reacting with di-t-butyl dicarbonate in a pyridine solution. Also,
Protecting the OH group with a t-butoxycarbonylmethyloxy group can be achieved by reacting t-butyl bromoacetate with a silicone polymer.

The method of protecting the OH group with a trimethylsilyl group can be carried out almost quantitatively by reaction with trimethylsilyl chloride in the presence of a base such as triethylamine or pyridine.

Further, the method of converting the OH group into tetrahydropyranylation can be easily carried out by reaction with dihydropyran in the presence of a weak acid.

The t-butoxycarbonylmethyloxy group produces a carboxy group when it is decomposed with a catalytic acid.
Since it has better solubility than those protected with a BOC group, a trimethylsilyl group, or a tetrahydropyranyl group, it has excellent resolution.

The blending amount of the silicone polymer used in the present invention is 55% (wt%, the same applies hereinafter) or more based on the total blending amount of both the three-component system and the two-component system together with other components.
Particularly, 80% or more is preferable. If the blending amount is less than 55%,
The coating property of the resist material may be poor, or the strength of the resist film may be poor.

The acid generator used in the present invention is represented by the following general formula (2), as described above.

(R )_pJM (2) (In the formula, R Is an aromatic group or a substituted aromatic group,
At least one is t-al represented by the following formula (2a).
Coxy group, t-butoxycarbonyl represented by formula (2b)
-Oxy group or t-butoxyl represented by formula (2c)
Is a phenyl group substituted with a bonylmethoxy group, and J is
Sulfonium or iodonium, M is p-toluene
Group or trifluoromethanesulfonate
Indicates a group. p is 2 or 3. )

[0028]

Embedded image (R ¹ represents a substituted or unsubstituted monovalent hydrocarbon group such as an alkyl group having 1 to 10 carbon atoms or an aryl group.)

[0029]

[Chemical 6] (T-Bu represents a t-butyl group.)

Examples of the onium salt of the above general formula (2) include the following. In general formula (2), the greater the number of R substituted with a t-alkoxy group, a t-butoxycarbonyloxy group, or a t-butoxycarbonylmethoxy group, the better the solubility tends to be.

[0031]

[Chemical 7] (In the formula, Tf represents p-trifluoromethanesulfonate, Ts represents p-toluenesulfonate, and t-B
OC represents a t-butoxycarbonyl group. )

The content of the onium salt is 0.5 to 15
%, Especially 1 to 10% is preferred. If it is less than 0.5%, positive resist characteristics are exhibited, but the sensitivity is low. When the content of the acid generator is increased, the resist sensitivity tends to be higher, the contrast (γ) is improved, and the positive type resist property is exhibited even if it is more than 15%. Due to the fact that sensitivity cannot be expected, the onium salt is an expensive reagent, the increase in low molecular weight components in the resist decreases the mechanical strength of the resist film, and the oxygen plasma resistance also decreases. Content of 1
It is preferably 5% or less.

The resist material of the present invention can be used not only as a two-component resist material comprising a silicone polymer represented by the general formula (1) and an onium salt represented by the general formula (2), but can also be dissolved if necessary. It can also be used as a three-component resist material containing a blocking agent.

As such a dissolution inhibitor, there are known 3
The same material as the component-based resist material can be used. For example, a material obtained by converting the OH group of bisphenol A represented by the following formula into t-BOC, or a material obtained by converting t-BOC such as phloroglucin or tetrahydroxybenzophenone into Can be used.

[0035]

Embedded image

The content of the dissolution inhibitor is preferably 40% or less,
It is particularly preferably set to 10 to 30%. When it is more than 40%, the oxygen plasma resistance of the resist film is remarkably lowered, so that it cannot be used as a two-layer resist.

The resist composition of the present invention can be prepared by dissolving the above silicone polymer, acid generator and, if necessary, a dissolution inhibitor in an organic solvent. As an organic solvent, these components are sufficiently dissolved. It is preferable that the resist film is uniformly spread, and specifically, butyl acetate, xylene, acetone, cellosolve acetate, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, lactic acid. Examples thereof include ethyl, methyl lactate, propyl lactate and butyl lactate. These organic solvents may be used alone or in combination of two or more. The amount of the organic solvent blended is preferably several times the total amount of the above components.

The resist material of the present invention may further contain a surfactant and the like.

Pattern formation using the resist material of the present invention can be performed, for example, as follows. First, the resist solution of the present invention is spin-coated on a substrate, prebaked, and irradiated with a high energy ray. At this time, the acid generator decomposes to generate an acid. PEB (Post E
By carrying out xpose Bake), the acid labile group is decomposed by using an acid as a catalyst and the dissolution inhibiting effect disappears. Then, a positive type pattern can be formed by developing with an alkaline aqueous solution and rinsing with water.

Further, the resist of the present invention, which uses a silicone polymer as a base resin, is excellent in oxygen plasma etching resistance and is therefore useful as a two-layer resist.

That is, after forming a thick organic polymer layer as a lower layer resist on a substrate, the resist solution of the present invention is spin coated thereon. The upper resist layer of the present invention is patterned by the same method as described above, and then the lower resist is selectively etched by etching, so that the upper resist pattern can be formed in the lower layer.

As the lower layer resist, a novolac resin type positive type resist can be used. After being coated on a substrate, it is hard baked at 200 ° C. for 1 hour to prevent intermixing with the silicone type resist. it can.

[0043]

Since the positive resist composition of the present invention is sensitive to high energy rays and has excellent sensitivity and resolution, it is useful for fine processing with electron beams or deep ultraviolet rays. Especially Kr
Since the absorption at the exposure wavelength of the F excimer laser is small,
The feature is that a fine pattern can be easily formed perpendicular to the substrate. Further, since it has excellent resistance to oxygen plasma etching, the two-layer resist in which the resist film of the present invention is applied on the lower layer resist is also characterized in that a fine pattern can be formed with a high aspect ratio.

[0044]

[Examples] The present invention will be specifically described below with reference to synthesis examples and examples, but the present invention is not limited to the following examples.

[Synthesis Example 1] Synthesis of polyhydroxyphenylalkylsilsesquioxane (a) o-Hydroxyphenylpropylsilsesquioxane 600 ml of water was charged into a reactor, and o-methoxyphenylpropyltrichlorosilane was stirred at 30 ° C. 28
A mixed solution of 3.5 g (1 mol) and 300 ml of toluene was added dropwise over 2 hours for hydrolysis. After the aqueous layer was removed by a liquid separation operation, the solvent was distilled off from the organic layer using an evaporator. The concentrate was heated under reduced pressure at 200 ° C. for 2 hours,
Polymerized. 200 g of acetonitrile was added to the polymer to dissolve it, and 240 g of trimethylsilyl iodide was added dropwise to the solution at 60 ° C. or lower, and the mixture was reacted at 60 ° C. for 10 hours. After completion of the reaction, 200 g of water was added for hydrolysis, and then a polymer layer was obtained by decanting. The polymer layer was vacuum-dried to obtain 192 g of poly o-hydroxyphenylpropylsilsesquioxane. (B) p-Hydroxyphenylethylsilsesquioxane (a) When p-methoxyphenylethyltrichlorosilane was used instead of o-methoxyphenylpropyltrichlorosilane in (a), the procedure of Synthesis Example (a) was repeated. 186 g of p-hydroxyphenylethylsilsesquioxane was obtained. (C) p-Hydroxybenzylsilsesquioxane (a) When p-methoxybenzyltrichlorosilane was used instead of o-methoxyphenylpropyltrichlorosilane in (a), the procedure of Synthesis Example (a) was repeated. 165 g of hydroxybenzylsilsesquioxane
Obtained.

[Synthesis Example 2] t-butoxycarbonyl (t of polyhydroxyphenylalkylsilsesquioxane)
-BOC) -modified polyhydroxybenzylsilsesquioxane (Synthesis example 1)
(C)) 25 g of pyridine was dissolved in 250 g of pyridine, and 45 ° C.
6.85 g of di-t-butyl dicarbonate with stirring
(0.031 mol, corresponding to about 20 mol% with respect to OH groups) was added. Gas was generated at the same time as the addition, but N
It was made to react for 1.5 hours in ₂ air streams. The reaction solution was stripped with pyridine, dissolved in 100 ml of methanol, and added dropwise to 5 liters of water to obtain a white precipitate. The precipitate was washed with water 5 times, filtered, and vacuum dried at 40 ° C. or lower to obtain 25 g of t-butoxycarbonylated polyhydroxybenzylsilsesquioxane (Synthesis Example 2 (c)). ^{In 1} H-NMR, the t-BOC conversion rate was calculated from the peak of the phenyl group at 6 to 7 ppm, the peak of the t-butyl group at ^{1 to} 2 ppm and the peak of methylene, and it was 19.6%.

Similarly, Synthesis Example 1 (a) and Synthesis Example 1 (b)
The polymer obtained in 1. was converted to t-BOC. Synthesis example 2
(A): t-BOC conversion rate, 19.5%: Synthesis example 2
(B): t-BOC conversion rate, 19.8%.

[Synthesis Example 3] t-butoxycarbonylmethylation of polyhydroxyphenylalkylsilsesquioxane Polyhydroxybenzylsilsesquioxane (Synthesis Example 1)
(C)) 25 g of pyridine was dissolved in 250 g of pyridine, and 45 ° C.
T-butyl bromoacetate 8.89 with stirring at
g (0.045 mol) was added, and the mixture was reacted for 5 hours in N ₂ gas stream. After stripping the reaction solution of pyridine, it was dissolved in 100 ml of methanol and added dropwise to 5 liters of water.
A white precipitate was obtained. The precipitate was washed with water 5 times, filtered, and vacuum dried at 40 ° C. or lower to obtain 25 g of t-butoxycarbonylmethyloxylated polyhydroxybenzylsilsesquioxane. ¹ H-NMR
At 6 to 7 ppm of phenyl group and 1-2
From the t-butyl group of ppm and the peak of methylene, t
As a result of obtaining the introduction rate of a -butoxycarbonylmethyloxy group, it was 20.6%.

[Synthesis Example 4] Trimethylsilylation of polyhydroxyphenylalkylsilsesquioxane Polyhydroxybenzylsilsesquioxane (Synthesis Example 1)
(C) 25 g was dissolved in 40 ml of acetone, and 5.2 g of trimethylamine was added. After adding 0.95 g of trimethylsilyl chloride with stirring at 45 ° C.,
The mixture was refluxed for 2 hours and aged. The reaction solution was stripped with acetone, dissolved in 100 ml of methanol, and added dropwise to 5 liters of water to obtain a white precipitate. The precipitate was washed with water 5 times, filtered, and vacuum dried at 40 ° C. or below.
25 g of trimethylsilylated polyhydroxybenzylsilsesquioxane was obtained. ^{In 1} H-NMR, the introduction rate of the trimethylsilyl group was determined from the peak of the phenyl group at 6 to 7 ppm and the peak of the methyl group of the trimethylsilyl group near 0 ppm, and the result was 19.0%.

[Synthesis Example 5] Tetrahydropyranylation of polyhydroxyphenylalkylsilsesquioxane Polyhydroxybenzylsilsesquioxane (Synthesis Example 1)
(C) 25 g of acetone was dissolved in 40 ml of acetone, 7.5 g of pyridinium tosylate was added, and dihydropyran 1 was added.
2.9 g was added over 1 hour with stirring at room temperature.
After aging at room temperature for 10 hours, the reaction solution was stripped with acetone, then dissolved in 100 ml of methanol and mixed with water 5
It was added dropwise to liter to obtain a white precipitate. Wash the precipitate with water 5
After repeating once, filtration and vacuum drying at 40 ° C. or lower gave 20 g of tetrahydropyranylated polyhydroxybenzylsilsesquioxane. ¹ H-NM
In R, the peak of the phenyl group at 6 to 7 ppm and 5.
The introduction rate of the tetrahydropyranyl group was calculated from the hydrogen peak at the α-position of the tetrahydropyranyl group at 5 ppm, and as a result, it was 18.9%.

Example 1 Base resin (Synthesis example 2 (c)) 96 parts by weight Tri (pt-butoxyphenyl) trifluoromethanesulfonate 4 parts by weight 1-ethoxy-2-propanol 600 parts by weight 2,000 rp of resist solution on silicon substrate
m and spin-coated at 85 ° C. for 1 minute on a hot plate. The film thickness was 0.4 μm. KrF
After drawing with an excimer laser or an electron beam with an acceleration voltage of 30 kV, PEB was performed at 85 ° C. for 2 minutes. 2.4%
Tetramethylammonium hydroxide (TMAH)
Development was carried out for 1 minute with an aqueous solution of, and rinsed with water for 30 seconds.

This resist material exhibits positive type characteristics,
The D ₀ sensitivity was 3 μC / cm ² . KrF excimer laser light (wavelength 248n, which is far ultraviolet light, is used instead of the electron beam.
Eth sensitivity when evaluated by m) is 4.0 mJ / cm ²
Met. The base resin used here showed a dissolution rate of 35 nm / s in the developing solution. The resist material had a dissolution rate of about 1.5 nm / s in the unexposed area and a dissolution rate of 40 nm / s in the exposed area after PEB.

With KrF excimer laser exposure, 0.2
A 5 μm line-and-space pattern and a hole pattern were resolved, and a pattern having sidewalls perpendicular to the substrate could be formed. In electron beam writing, the resolution was 0.1 μm.

Examples 2-33 A base resin and an acid generator having the same composition as in Example 1 were prepared as shown in Table 1. Coating on a silicon wafer substrate under the same conditions as in Example 1, and Kr
F excimer laser exposure was performed. Table 1 shows the sensitivity and the resolution line width of the line and space.

Example 34 Base Resin (Synthesis Example 2 (c)) 80 parts by weight Tri (pt-butoxyphenyl) trifluoromethanesulfonate 4 parts by weight t-BOC bisphenol A 16 parts by weight 1-ethoxy A resist solution consisting of 600 parts by weight of 2-propanol was spin-coated on a silicon substrate at 2,000 rpm under the same conditions as in Example 1, and prebaked on a hot plate at 85 ° C. for 1 minute. The film thickness is 0.
It was 4 μm. KrF excimer laser exposure was performed. As a result, the sensitivity was 20 mJ / cm ² , and the resolution line width of line and space was 0.22 μm.

[Examples 35 to 37] A base resin, an acid generator and a dissolution inhibitor having the same composition as in Example 28 were prepared as shown in Table 2. It was applied onto a silicon wafer substrate under the same conditions as in Example 28 and subjected to KrF excimer laser exposure. Table 2 shows the sensitivity and line and space resolution line width.
Shown in

[0057]

[Table 1]

[0058]

[Table 2]

Example 38 A resist solution having the same composition as in Example 1 was prepared, and OFPR800 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a lower layer resist was applied to a silicon wafer to a thickness of 2 μm and heated at 200 ° C. for 1 hour. And cured. The resist material of Example 1 was applied on the lower layer resist in the same manner as in Example 1 to a thickness of about 0.4 μm, and prebaked. In the same manner as in Example 1, exposure and development were performed with an electron beam or KrF excimer laser to form a pattern on the lower layer resist.

After that, etching was performed with a parallel plate type sputter etching apparatus using oxygen gas as an etchant gas. Etching rate of lower layer resist is 150 nm / m
whereas the resist of the composition of Example 1 is 3n
It was below m / min. By performing the etching for 15 minutes, the lower layer resist not covered with the resist completely disappeared, and a two-layer resist pattern having a thickness of 2 μm or more could be formed. The etching conditions are shown below. Gas flow rate: 50 SCCM, gas pressure: 1.3 Pa rf power: 50 W, dc bias: 450 V

[Examples 39 to 70] Under the same conditions as in Example 38, the resist material of Examples 2 to 33 was used as a two-layer resist instead of the resist of Example 1, and the same pattern was formed. I was able to.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03F 7/075 511 521 H01L 21/027 (72) Inventor Toshinobu Ishihara Kubiki Village, Nakakubiki District, Niigata Prefecture 28-1 Nishi-Fukushima Shin-Etsu Chemical Co., Ltd. Synthetic Technology Laboratory (72) Inventor Keijun Tanaka 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Yoshio Kawai Chiyoda, Tokyo 1-6 Sachimachi, Saitama, Japan Nippon Telegraph and Telephone Corp. (72) Inventor Jiro Nakamura 1-1-6, Uchisaimachi, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp.

Claims (2)

[Claims] 1. The following general formula (1):(In the formula, Q is t-butoxycarbonyl group, t-butoxy
Carbonylmethyl group, trimethylsilyl group or tetrahydo
Indicates a dolopyranyl group. n is an integer of 1 to 3, x and m are x
Although + m = 1, x never becomes 0. )
Silicone polymer and the effect of the applied radiation
An acid containing two components, an acid generator that decomposes to generate an acid
It is a positive resist material that can be developed with Lucari aqueous solution.
And the acid generator is represented by the following general formula (2) (R )_pJM (2) (In the formula, R Is an aromatic group or a substituted aromatic group,
At least one is R¹ ₃CO- (R¹Has 1 to 10 carbon atoms
Represents a substituted or unsubstituted monovalent hydrocarbon group)
-Alkoxy group, t-butoxycarbonyloxy group or
Phenyl substituted with t-butoxycarbonylmethoxy group
Is a sulfonyl group and J is sulfonium or iodonium.
And M is a p-toluene sulfonate group or trifluoro
Indicates a methanesulfonate group. p is 2 or 3
It ) Is an onium salt represented by
Di-type resist material. 2. The material according to claim 1, further comprising a dissolution inhibitor.