JPH10213899A - Acid producing agent for resist material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an acid producing agent suitable for a resist material for photolithography which uses far UV rays or KrF excimer laser light as the light source by incorporating a specified compd. SOLUTION: This acid producing agent for a resist material contains a compd. expressed by formula. In the formula, R9 is a branched or cyclic alkyl group having 3 to 10 carbon atoms and R10 is a straight-chain, branched or cyclic alkyl group having 1 to 10 carbon atoms. This acid producing agent for a resist material is suitable for such a resist material that uses chemical amplification so as to decrease the energy amt. of exposure light to the min. as possible, especially for a resist material when far UV light of <=300nm wavelength, for example 248.8nm KrF excimer laser light is used as the energy source for exposure. The resist material above described usually consists of an acid producing agent, a polymer which can be changed into alkali soluble by the effect of acid, and a solvent which dissolves these compds.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acid generator for a resist material used in the manufacture of semiconductor devices and the like. More specifically, the present invention relates to an acid generator suitable for a resist material for light source exposure such as far ultraviolet light of 300 nm or less as an exposure energy source, for example, KrF excimer laser light of 248.4 nm.

[0002]

2. Description of the Related Art In recent years, with the high-density integration of semiconductor devices, the light source of an exposure apparatus used for fine processing, especially for photolithography, has been increasingly shortened in wavelength, and KrF excimer laser (248.4 nm) light is now being studied. It has become. However, no suitable resist material has been found yet for this wavelength.

For example, as a resist material using KrF excimer laser light or far-ultraviolet light as a light source, a resin having high transparency to light near 248.4 nm and a general formula [2]

[0004]

Embedded image

A dissolution-inhibiting resist material comprising a photosensitive compound having a group represented by the following formula has been developed (for example, JP-A-1-80944; JP-A-1-54048; JP-A-1-155338). Gazette; JP-A-1-155339; JP-A-1-155339
No. 188852; Y. Tani et al., SPIE's1989 Sympo., 1086-03.
etc). However, these dissolution-inhibiting resist materials have low sensitivity in common, and cannot be used for deep ultraviolet light or KrF excimer laser light, which requires high-sensitivity resist materials.
In recent years, a chemically amplified resist material using an acid generated by exposure as a medium has been proposed as a method for reducing the amount of exposure energy (higher sensitivity) [H. Ito et al., Polym. Eng.
ci., 23, 1012 (1983)], and various reports have been made on this (for example, H. Ito et al., US Patent No. 4491628).
No. (1985); JVCrivello, U.S. Pat.No. 4,603,101 (1986);
WRBrunsvold et al., SPIE's 1989 Sympo., 1086-40; T. Neenan
Et al., SPIE's 1989 Sympo., 1086-01; JP-A-62-115440. However, these existing chemically amplified resist materials, the resin used is, for example, poly (4-tert-butoxycarbonyloxystyrene), poly (4-tert-butoxycarbonyloxy-α-methylstyrene), poly (4-te
In the case of phenol ether resins such as (rt-butoxystyrene) and poly (4-tert-butoxy-α-methylstyrene), all have poor heat resistance, and the film peels off during development due to poor adhesion to the substrate. And has the drawback that a good pattern shape cannot be obtained.In addition, in the case of a carboxylic acid ester-based resin, for example, poly (tert-butyl-4-vinylbenzoate) or the like, Due to the ring, the light transmittance around 248.4 nm is insufficient, and in the case of poly (tert-butyl methacrylate) etc., the resin has poor heat resistance and poor dry etch resistance. I have.

[0006] Further, at present, development of an acid generator suitable for use of far ultraviolet light, KrF excimer laser light, or the like as a light source is in great demand.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an acid generator suitable for a resist material for photolithography using far ultraviolet light, KrF excimer laser light or the like as a light source. I do.

[0008]

To achieve the above object, the present invention comprises the following constitutions. "(1) General formula [1]

[0009]

Embedded image

(Wherein, R 9 represents a branched or cyclic alkyl group having 3 to 10 carbon atoms, and R 10 represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms) An acid generator for a resist material comprising a compound represented by the formula: "

That is, the present inventors have high light transmittance to light of 300 nm or less, for example, far-ultraviolet light, particularly KrF excimer laser light, and perform exposure by such an exposure light source, electron beam, X-ray. A new acid generator that easily generates acid by irradiation, etc., and the generated acid effectively acts on the chemical amplification of the resist material by heating, and itself has excellent solution stability in the resist material. As a result of intensive studies, they have found that the compound represented by the general formula [1] can achieve the object, and have completed the present invention.

In the general formula [1], R 9 and R 10 are preferably each independently a branched or cyclic alkyl group having 3 to 10 carbon atoms, and more preferably each is independently a C 6 to C 6 alkyl group. 10 cyclic alkyl groups.

Specific examples of the acid generator for resist material represented by the general formula [1] of the present invention include, for example, bis (isopropylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, 1-cyclohexylsulfonyl-1-tert- Butylsulfonyldiazomethane and the like, but are not limited thereto.

The acid generator for resist material of the present invention is a resist material utilizing chemical amplification in order to reduce the amount of exposure energy as much as possible, especially as an exposure energy source.
It is suitable as a resist material when far-ultraviolet light of 300 nm or less, for example, KrF excimer laser light of 248.4 nm is used. Such a resist material usually comprises an acid generator, a polymer which becomes alkali-soluble by the action of an acid, and a solvent capable of dissolving them. As a polymer used for preparing such a resist material using the acid generator of the present invention, under the coexistence of an acid generated from a photosensitive compound by exposure, undergoes a chemical change by heating to become alkali-soluble. The following general formula [3] comprising a monomer unit having a functional group, a monomer unit having a phenolic hydroxyl group and, if necessary, a third monomer unit

[0015]

Embedded image

Wherein R 1 is a methyl group, an isopropyl group, a tert-butyl group, a tetrahydropyranyl group or a tert-
Represents a butoxycarbonyl group, R2 represents a hydrogen atom or a methyl group, and k and l each independently represent a natural number {provided that k / (k + 1) = 0.1 to 0.9. Represents｝. ]
Or a polymer represented by the following general formula [4]

[0017]

Embedded image

Wherein R 1 is a methyl group, an isopropyl group, a tert-butyl group, a tetrahydropyranyl group or a tert-
R2 represents a hydrogen atom or a methyl group; R3 and R5 each independently represent a hydrogen atom or a methyl group; R4 represents a hydrogen atom, a carboxyl group, a cyano group or a general formula [5]

[0019]

Embedded image

Wherein R 7 represents a hydrogen atom, a halogen atom or a lower alkyl group, and R 6 represents a hydrogen atom, a cyano group or —COOR 8 (where R 8 has 1 to 1 carbon atoms)
Represents 10 linear, branched or cyclic alkyl groups. )
Where k ′, l ′ and m are each independently a natural number, provided that 0.1 ≦ k ′ / (k ′ + l ′) ≦ 0.9 and 0.05 ≦ m 2
(K ′ + l ′ + m) ≦ 0.50 °. ). (Hereinafter, abbreviated as the polymer according to the present invention).

The monomer having a functional group (hereinafter, abbreviated as “specific functional group”) that becomes alkali-soluble by heating under an acid atmosphere has a protecting group which is eliminated by an acid.
P- or m-hydroxystyrene derivatives and p- or m-hydroxy-α-methylstyrene derivatives are preferred. More specifically, p- or m-methoxystyrene, p- or m-isopropoxystyrene, p- or m-tert-butoxystyrene, p- or m
-Tetrahydropyranyloxystyrene, p- or m-tert-
Butoxycarbonyloxystyrene and their p- or m-
P- or m-hydroxy-α-methylstyrene derivatives having the same protective group as the hydroxystyrene derivative. Further, as a monomer having a phenolic hydroxyl group, p- or m-vinylphenol and p- or m-hydroxy-
α-methylstyrene. The polymer according to the present invention has, as a third monomer unit, for example, α-methylstyrene, p-chlorostyrene, as a third monomer unit for the purpose of increasing the light transmittance around 248.4 nm of the entire polymer in addition to the two types of monomer units as described above. It may contain monomer units such as acrylonitrile, fumaronitrile, methyl methacrylate, tert-butyl methacrylate, and tert-butyl p-ethenylphenoxyacetate.

In the polymer according to the present invention, the constitutional ratio of the monomer unit having the specific functional group to the monomer unit having a phenolic hydroxyl group is usually from 1: 9 to 9: 1, and in any case, it is preferable. Is 2: 8 to 7: 3. By doing so, the heat resistance of the polymer and the adhesion to the substrate become extremely good.

Specific examples of the polymer according to the present invention include, for example, p-isopropoxystyrene-p-hydroxystyrene polymer, p-tetrahydropyranyloxystyrene-p-hydroxystyrene polymer, p-tert-butoxystyrene- p-
Hydroxystyrene polymer, p-tert-butoxycarbonyloxystyrene-p-hydroxystyrene polymer, p-methoxy-α-methylstyrene-p-hydroxy-α-methylstyrene polymer, p-tert-butoxycarbonyloxystyrene- p-hydroxystyrene-methyl methacrylate polymer, p-tetrahydroxypyranyloxystyrene-p-hydroxystyrene-tert-butyl methacrylate polymer, p
-tert-butoxystyrene-p-hydroxystyrene-fumaroniloryl polymer, p-tert-butoxystyrene-p-hydroxystyrene-tert-butyl methacrylate polymer, p-
tert-butoxystyrene-p-hydroxystyrene-acrylonitrile polymer, p-tert-butoxystyrene-p-hydroxystyrene-p-ethenylphenoxyacetic acid tert-butyl polymer, m-isopropoxystyrene-p- or m- Hydroxystyrene polymer, m-tetrahydropyranyloxystyrene-p- or m-hydroxystyrene polymer, m-te
rt-butoxystyrene-p- or m-hydroxystyrene polymer, m-tert-butoxycarbonyloxystyrene-p-
Or m-hydroxystyrene polymer, m-methoxy-α-methylstyrene-p- or m-hydroxy-α-methylstyrene polymer, m-tert-butoxycarbonyloxystyrene −
p- or m-hydroxystyrene-methyl methacrylate polymer, m-tetrahydroxypyranyloxystyrene-p- or m-hydroxystyrene-tert-butyl methacrylate polymer, m-tert-butoxystyrene-p- or m -Hydroxystyrene-fumaroniloryl polymer, p-tert-butoxystyrene-p- or m-hydroxystyrene-methacrylic acid te
rt-butyl polymer, m-tert-butoxystyrene-p- or m-
Hydroxystyrene-acrylonitrile polymer and m-te
rt-butoxystyrene-p- or m-hydroxystyrene-p
-Ethenylphenoxyacetic acid tert-butyl polymer; and the like, but is not limited thereto.

The polymers according to the present invention include, for example, the following a) to c)
Can be easily obtained by the following three methods. a) Method-1 The above monomer having a specific functional group alone or the third monomer is mixed with an organic solvent such as benzene, toluene, tetrahydrofuran or 1,4-dioxane in accordance with a conventional method for producing a polymer. A radical polymerization initiator [eg, 2,2 ′
Polymerization initiators such as -azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (methyl 2-methylpropionate) and benzoyl peroxide , A peroxide-based polymerization initiator such as lauroyl peroxide, etc.] in a nitrogen or argon stream at 50 to 110 ° C for 1 to 10 hours. After the reaction, a post-treatment is carried out according to a conventional method of obtaining a polymer to isolate a polymer comprising the monomer unit having the specific functional group or a copolymer containing the monomer unit having the specific functional group. . Then, the polymer or copolymer is dissolved in an organic solvent such as tetrahydrofuran, acetone or 1,4-dioxane with a suitable acid [for example, a proton such as sulfuric acid, phosphoric acid, hydrochloric acid, hydrobromic acid, p-toluenesulfonic acid or the like. Acids are preferred. ] And 30 ~ 100 ℃ 1
The reaction is allowed to proceed for 10 hours to remove the above-mentioned specific functional group at an arbitrary ratio. After the reaction, a post-treatment is carried out according to a conventional method for obtaining a polymer, and a desired polymer is isolated.

B) Method-2 The above-mentioned monomer having a specific functional group, p-hydroxystyrene (or p-hydroxy-α-methylstyrene) and, if necessary, a third monomer are used in the same manner as in method-1. After the copolymerization according to the above procedure, a post-treatment is carried out in accordance with a conventional method for obtaining a polymer to isolate a desired polymer.

C) Method-3 Polymerization or copolymerization of p-hydroxystyrene (or p-hydroxy-α-methylstyrene) alone or this and a third monomer in the same manner as in Method-1. After
The above-mentioned specific functional group is chemically introduced into the obtained polymer or copolymer at an arbitrary ratio, and then post-treatment is carried out in accordance with a conventional method for obtaining a polymer to isolate a desired polymer.

The polymer according to the present invention can be obtained by any of these three methods. However, the polymer obtained by the method-1 has 248.4 nm compared with those obtained by the other methods. It is most preferable because the light transmittance in the vicinity is remarkably excellent.

This is described in detail below by taking as an example the most typical poly (p-tert-butoxystyrene-p-hydroxystyrene) among the polymers according to the present invention represented by the general formula [3]. Will be described. That is, poly (p-tert-butoxystyrene-p-hydroxystyrene) obtained by Method-1 and poly (p-tert-butyrene) obtained by the other two methods.
Butoxystyrene-p-hydroxystyrene) (the ratio of each unit of the polymer was 1: 1) was formed, and the light transmittance around 248.4 nm at a film thickness of 1 μm was compared. The transmittance of the combined polymer was about 70%, while the transmittance of each of the other polymers was about 55 to 61%. Since this difference in transmittance is used in photolithography for ultrafine processing, it is a fatal difference as a polymer for a photoresist which requires higher resolution performance.

The average molecular weight of the polymer according to the present invention is not particularly limited as long as it can be used as a resist material. The preferred range is the weight determined by a GPC measurement method using polystyrene as a standard. Average molecular weight is usually about 1000 to 40,000, preferably 3000 to 20000
It is about.

The solvent used for preparing the resist material using the acid generator of the present invention may be any solvent as long as it can dissolve both the polymer and the acid generator. Those having no absorption around 230 to 300 nm are more preferably used. Specifically, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monoethyl ether acetate, methyl lactate, ethyl lactate, 2-ethoxyethyl acetate, methyl pyruvate,
Ethyl pyruvate, methyl 3-methoxypropionate, 3-
Ethyl methoxypropionate, N-methyl-2-pyrrolidone, cyclohexanone, methyl ethyl ketone, 1,4-dioxane, ethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether or diethylene glycol dimethyl ether, and the like,
Of course, it is not limited to these.

The resist composition thus prepared usually contains the above three components (polymer, acid generator, solvent) as main constituents, but may contain dyes and surfactants if necessary. May be.

In order to form a pattern using the resist material according to the present invention as described above, for example, the following may be performed. A resist material containing the compound according to the present invention is applied on a substrate such as a silicon wafer so as to have a thickness of about 0.5 to 2 μm (when used as an upper layer of three layers,
0.1 ~ 0.5μm), this in an oven at 70 ~ 130 ℃, 10
~ 30 minutes or 70 ~ 130 ℃ on hot plate, 1 ~
Pre-bake for 2 minutes. Next, a mask for forming a target pattern is held over the resist film, and 300 n
Exposure dose of less than 1 m deep ultraviolet light 1 ~ 100mJ / cm
After irradiating to about ² , using a developing solution such as 0.1 to 5% tetramethylammonium hydroxide (TMAH) aqueous solution, about 0.5 to 3 minutes, immersion method, paddle (puddle) method,
If development is performed by a conventional method such as a spray method, a target pattern is formed on the substrate.

The mixing ratio of the acid generator of the present invention to the polymer of the present invention in the positive resist composition is 0.01 to 0.3 weight per 1 weight of the polymer.
Preferably about 0.01 to 0.1 weight is used. In addition, the amount of the solvent in the resist material of the present invention impairs the application of a positive resist material obtained by dissolving the polymer of the present invention and the acid generator of the present invention on a substrate. The amount is not particularly limited as long as it is not an amount, but is usually 1 to 20 weight per 1 weight of the polymer, preferably
1.5 to around 6 weight.

The developing solution used in the above-mentioned various pattern forming methods hardly dissolves the unexposed portion, and hardly dissolves the exposed portion, depending on the solubility of the resin used for the resist material in an alkaline solution. It is sufficient to select an alkaline solution having an appropriate concentration to dissolve, usually 0.01 to 20.
% Range. Examples of the alkaline solution used include a solution containing an organic amine such as TMAH, choline, and triethanolamine, and a solution containing an inorganic alkali such as NaOH and KOH.

The polymer according to the present invention has heat resistance, dry etch resistance, and excellent adhesion to a substrate due to the inclusion of a component having a hydroxystyrene skeleton. . Further, the polymer according to the present invention produced by the above-mentioned method-1 has remarkably excellent light transmittance around 248.4 nm as compared with the same kind of polymer (having a hydroxystyrene skeleton) obtained by another method. .

It has been confirmed that the acid generator of the present invention causes an acid by irradiation with an electron beam or X-ray as well as KrF excimer laser light. Therefore, the acid generator of the present invention is used as a resist material for forming a pattern by a low exposure dose of deep ultraviolet light, KrF excimer laser light (248.4 nm) or an electron beam or X-ray irradiation method using a chemical amplification method. It is suitable as an acid generator.

[0037]

The operation of the present invention will be described with reference to specific examples. First, an acid is generated in a portion exposed to KrF excimer laser light, far ultraviolet light or the like according to, for example, a photoreaction represented by the following formula 1.

[0038]

(Equation 1)

When a heat treatment is performed following the exposure step, the following formula 2 is obtained.
According to the reaction formula, a specific functional group of the polymer according to the present invention (exemplified as a tert-butoxy group in Formula 2) undergoes a chemical change with an acid to become a hydroxyl group and becomes alkali-soluble. Eluted.

[0040]

(Equation 2)

On the other hand, since no acid is generated in the unexposed area, no chemical change occurs even by heat treatment. Instead, the acid generator forms the hydrophilic group site of the polymer used for the purpose of enhancing the adhesion to the substrate. An effect of protecting from infiltration of the alkali developing solution is exhibited. Thus, when a pattern is formed using the resist material containing the acid generator of the present invention, a large solubility difference in an alkali developing solution occurs between an exposed portion and an unexposed portion, and the unexposed portion Since the resin in the portion has strong adhesion to the substrate, the film does not peel during development, and as a result, a positive pattern having good contrast is formed. Further, as shown in the above formula 2, the acid generated by the exposure acts as a catalyst, so that the exposure only needs to generate the necessary acid, and the amount of exposure energy can be reduced.

Hereinafter, the present invention will be described in more detail with reference to Examples, Production Examples and Reference Examples, but the present invention is not limited by these.

[0043]

【Example】

REFERENCE EXAMPLE 1 Synthesis of poly (p-tert-butoxystyrene-p-hydroxystyrene) -1 (1) To 17.6 g of p-tert-butoxystyrene, a catalytic amount of 2,2'-azobisisobutyronitrile was added, and toluene solvent was added. The polymerization reaction was carried out at 80 ° C. for 6 hours in a medium and nitrogen stream. After cooling, the reaction solution was poured into methanol for crystallization, and the precipitated crystals were collected by filtration, washed with methanol, and dried under reduced pressure to obtain 15.5 g of poly (p-tert-butoxystyrene) as white powder crystals. Weight average molecular weight approx.
10000 (GPC method: polystyrene standard).

(2) 15.0 g of the poly (p-tert-butoxystyrene) obtained in the above (1) was dissolved in 1,4-dioxane, and 10 ml of concentrated hydrochloric acid was added.
Was added and stirred under reflux for 1.5 hours.After cooling, the reaction solution was poured into water, crystallized, and the precipitated crystals were collected by filtration, washed with water, and dried under reduced pressure to obtain poly (p-tert-butoxystyrene-p-hydroxystyrene). 11.8 g was obtained as white powder crystals. P- of the obtained polymer
The composition ratio of tert-butoxystyrene unit to p-hydroxystyrene unit was about 1: 1 by ¹ HNMR measurement. Weight average molecular weight about 10,000 (GPC method: polystyrene standard).

Reference Example 2 Synthesis of poly (p-tert-butoxystyrene-p-hydroxystyrene) -2 Reference was used except that 3.5 g (0.02 mol) of p-tert-butoxystyrene and 2.7 g (0.022 mol) of p-hydroxystyrene were used as starting materials. After conducting the polymerization reaction in the same manner as in Example 1, the reaction solution was poured into petroleum ether, crystallized, and the precipitated crystals were collected by filtration.
After washing and drying under reduced pressure, poly (p-tert-butoxystyrene-p-
5.0 g of hydroxystyrene) were obtained as white powdery crystals. The composition ratio of p-tert-butoxystyrene unit and p-hydroxystyrene unit of the obtained copolymer is about 1: 1 by ¹ H NMR measurement.
Met. Weight average molecular weight about 10,000 (GPC method: polystyrene standard).

Reference Example 3 Synthesis of poly (p-tert-butoxystyrene-p-hydroxystyrene) -3 (1) A polymerization reaction was carried out in the same manner as in Reference Example 1 except that 5.0 g of p-hydroxystyrene was used as a starting material.
The precipitated crystals were collected by filtration, washed and dried under reduced pressure to obtain 4.2 g of poly (p-hydroxystyrene) as white powder crystals.

(2) A solution of 4.0 g of poly (p-hydroxystyrene) obtained in the above (1) in dimethoxyethane (70 ml) was placed in a pressure vessel, and 60 g of isobutylene and 0.3 ml of sulfuric acid were added at −60 ° C. or lower. Was. Then, the reaction was stirred at 45 ° C. for 1 hour and then at room temperature for 22 hours. After the reaction, the reaction solution was concentrated, the residue was neutralized with sodium carbonate, poured into water and crystallized, and the precipitated crystals were collected by filtration, washed with water, and dried under reduced pressure to obtain poly (p-tert-butoxystyrene-p-hydroxy). 4.1 g of styrene) were obtained as white powdery crystals. P-tert-butoxystyrene unit of the obtained polymer and p
The composition ratio of -hydroxystyrene unit is about ¹ HNMR
It was 1: 1. Weight average molecular weight about 10,000 (GPC method: polystyrene standard).

Reference Example 4 Synthesis of poly (p-tert-butoxystyrene-p-hydroxystyrene-fumaronitrile) (1) 28.2 g (0.16 mol) of p-tert-butoxystyrene and 3.1 g (0.04 mol) of fumaronitrile were added to 2,2′-azobis (2 (Methyl-methylpropionate) in a toluene solvent under a nitrogen stream at 90 ° C. for 2 hours. After the reaction, the reaction solution was poured into methanol for crystallization, and the precipitated crystals were collected by filtration, washed,
After drying, 21.3 g of poly (p-tert-butoxystyrene-fumaronitrile) was obtained as white powder crystals.

(2) Production Example 1 (2) using 20.0 g of poly (p-tert-butoxystyrene-fumaronitrile) obtained in (1) above.
The reaction and post-treatment were carried out in the same manner as described above, and poly (p-tert-butoxystyrene-p-hydroxystyrene-fumaronitrile) 15.
4 g were obtained as white powder crystals. P-tert- of the obtained polymer
The ratio of butoxystyrene units to p-hydroxystyrene units was about 1: 1 as determined by ¹ HNMR. Weight average molecular weight about 12000 (GPC method: polystyrene standard).

Reference Example 5 Synthesis of poly (p-tert-butoxystyrene-p-hydroxystyrene-methyl methacrylate) (1) A catalytic amount of 25.8 g (0.09 mol) of p-tert-butoxystyrene and 1.0 g (0.09 mol) of methyl methacrylate were added. , 2'-Azobis (2,4-dimethylvaleronitrile) was added, and a polymerization reaction was carried out in toluene at 80 ° C for 8 hours in a nitrogen stream. After cooling the reaction solution, it was poured into petroleum ether, crystallized, and the precipitated crystals were collected by filtration, washed with petroleum ether, and dried under reduced pressure to obtain 10.9 g of poly (p-tert-butoxystyrene-methyl methacrylate) as white powder crystals. Obtained.

(2) 10.5 g of the poly (p-tert-butoxystyrene-methyl methacrylate) obtained in the above (1) was dissolved in 1,4-dioxane, 1 g of p-toluenesulfonic acid was added, and the mixture was stirred and refluxed.
Perform 1.5 hours, after cooling, inject the reaction solution into water, crystallize,
The precipitated crystals were collected by filtration, washed with water, and dried under reduced pressure to obtain 7.1 g of poly (p-tert-butoxystyrene-p-hydroxystyrene-methyl methacrylate) as white powder crystals. Pt of the polymer obtained
The composition ratio of ert-butoxystyrene unit to p-hydroxystyrene unit was about 4: 6 by ¹ HNMR measurement. Weight average molecular weight about 15000 (GPC method: polystyrene standard).

Production Example 1. Synthesis of bis (cyclohexylsulfonyl) diazomethane (1) 22.5 g (0.35 mol) of sodium azide was dissolved in a small amount of water and diluted with 130 ml of 90% aqueous ethanol. Then, at 10 to 25 ° C., 60 g of p-toluenesulfonyl chloride (0.32
(Mol) was added dropwise, and 2.5
Allowed to react for hours. Then, the reaction solution was concentrated under reduced pressure, and the residual oily product was washed several times with water and dried over anhydrous magnesium sulfate. The desiccant was filtered off and p-toluenesulfonyl azide 50.7
g was obtained as a colorless oil. 1 NMR δ ppm (deuterated chloroform): 2.43 (3H, s, methyl group), 7.24 (2H, d, J = 8 Hz, aromatic ring 3-H, 5-H), 7.67 (2H, d, J
= 8 Hz, aromatic ring 2-H, 6-H). IR (Neat) cm-1: 2120.

(2) To 20.2 g (0.17 mol) of cyclohexylthiol was added dropwise an ethanol solution of 12.0 g (0.21 mol) of potassium hydroxide at room temperature, and the mixture was stirred and reacted at 30 ± 5 ° C. for 30 minutes. Then, 18.2 g (2.14 mol) of methylene chloride was injected, and the mixture was heated at 50 ± 5 ° C for 6 hours.
The reaction was stirred for a period of time. After standing at room temperature overnight, 55 ml of ethanol was poured into the reaction solution, diluted, and sodium tungstate was added.
After adding 400 mg, 30 g of hydrogen peroxide 50 g (0.44 mol) was added to 45 g
The mixture was added dropwise at 5050 ° C., and further reacted with stirring at the same temperature for 4 hours. After the reaction, 200 ml of water was poured and the mixture was allowed to stand overnight at room temperature. The precipitated crystals were collected by filtration, washed with water and dried, and 22 g of crude crystals were recrystallized from ethanol to obtain 15.5 g of bis (cyclohexylsulfonyl) methane.
Was obtained as white needles. 137-139 ° C. 1 NMR δ ppm (deuterated chloroform): 1.13 to 2.24 (20H, m, cyclohexane ring methylene × 10), 3.52 to 3.66 (2H, m, cyclohexane ring methine × 2), 4.39 (2H, s, methylene). IR (KBr) cm-1: 1320, 1305.

(3) 1.7 g of sodium hydroxide was dissolved in 70 ml of 60% aqueous ethanol, and to this was added 12.1 g (0.04 mol) of bis-cyclohexylsulfonylmethane obtained in the above (2). Next, an ethanol solution of 8.2 g (0.04 mol) of p-toluenesulfonyl azide obtained in the above (1) was added dropwise at 5 to 10 ° C.,
Then, the reaction was stirred at room temperature for 7 hours. After left overnight at room temperature, the precipitated crystals were collected by filtration, washed with ethanol and dried, and 11 g of the crude crystals were recrystallized from acetonitrile to obtain 8.0 g of bis (cyclohexylsulfonyl) diazomethane as slightly yellow prism crystals. mp. 130-131 ° C. 1NMR δ ppm (deuterated chloroform): 1.13 to 2.25 (20H, m, cyclohexane ring methylene × 10), 3.36 to 3.52 (2H, m, cyclohexane ring methine × 2). IR (KBr) cm-1: 2130, 1340, 1320.

Examples 1 to 5 After a resist material containing 0.6 g of a predetermined polymer, 0.3 g of an acid generator of the present invention and 13.7 g of diethylene glycol dimethyl ether was prepared, a pattern was formed as described later. Was. A pattern forming method using the above resist material will be described with reference to FIG. The resist material 2 was spin-coated on a semiconductor substrate 1 and soft-baked on a hot plate at 90 ° C. for 90 seconds to obtain a resist material film having a thickness of 1.0 μm (FIG. 1A). Next, a 248.4 nm KrF excimer laser beam 3 was selectively exposed through a mask 4 (FIG. 1).
(b)). Then, after baking on a hot plate at 110 ° C. for 90 seconds, development is performed for 60 seconds with an alkali developing solution (2.38% aqueous solution of tetramethylammonium hydroxide) to dissolve and remove only the exposed portions of the resist material 2, thereby forming the positive pattern 2a. (FIG. 1 (c)). Table 1 shows the obtained results.

[0057]

[Table 1]

From the results shown in Table 1, when a pattern is formed using the resist material containing the acid generator of the present invention, a fine pattern with a good shape on the order of submicrons can be easily obtained. I understand. From the results of Examples 1 to 3, when a pattern was formed using the resist material containing the polymer obtained in Reference Example 1, the same type of material obtained by the other two manufacturing methods was used. Polymer (Reference Example 2)
It can be seen that a finer pattern can be easily obtained with a small amount of exposure energy as compared with the resist material containing (3) and (3).

[0059]

As is apparent from the above description, the resist material prepared by using the acid generator of the present invention has a thickness of 300 nm.
The following light sources, for example, deep ultraviolet light (Deep UV), for example, Kr
When used as a resist material for exposure to F excimer laser light (248.4 nm) or the like, a fine pattern with a good shape on the order of submicrons can be easily obtained. Therefore, the present invention has great value for forming ultrafine patterns in the semiconductor industry and the like.

Incidentally, the acid generator of the present invention can be obtained by
It is particularly effective as an acid generator at the time of pattern formation using F excimer laser light, but can be sufficiently used as an acid generator at the time of pattern formation using i-ray light, electron beam, X-ray, or the like. .

[0061]

[Brief description of the drawings]

FIG. 1 is a process cross-sectional view of a positive pattern forming method using a resist material containing an acid generator of the present invention.

[0062]

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Resist material film containing acid generator of this invention, 3 ... KrF excimer laser light, 4 ... Mask,
2a: Resin pattern.

 ──────────────────────────────────────────────────続 き Continuing on the front page (31) Priority claim number Japanese Patent Application No. Hei 2-19617 (32) Priority date Hei 2 (1990) January 30 (33) Priority claim country Japan (JP) (31) Priority Claim number Japanese Patent Application No. 2-329552 (32) Priority date Hei 2 (1990) November 30 (33) Priority claiming country Japan (JP) (72) Inventor Keiji Ohno Kawaji-shi, Saitama 1633 Waza Jun Wako Yakuhin Kogyo Co., Ltd.

Claims (7)

[Claims] 1. A compound of the general formula [1] (In the formula, R9 represents a branched or cyclic alkyl group having 3 to 10 carbon atoms, and R10 represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms.) An acid generator for a resist material, comprising a compound. 2. The acid generator according to claim 1, wherein the resist material is a resist material using KrF excimer laser light. 3. R9 and R10 each independently have 3 to 1 carbon atoms.
3. The acid generator for a resist material according to claim 1, which is a branched or cyclic alkyl group of 0. 4. R9 and R10 each independently have 6 to 1 carbon atoms.
The acid generator for a resist material according to claim 1, wherein the acid generator is 0 cyclic alkyl group. 5. The acid generator for a resist material according to claim 1, wherein the compound represented by the general formula [1] is bis (isopropylsulfonyl) diazomethane. 6. The acid generator for a resist material according to claim 1, wherein the compound represented by the general formula [1] is bis (cyclohexylsulfonyl) diazomethane. 7. The acid generator for a resist material according to claim 1, wherein the diazodisulfone compound represented by the general formula [1] is 1-cyclohexylsulfonyl-1-tert-butylsulfonyldiazomethane. [0001]