JPH04210960A - Novel diazodisulfone compound - Google Patents

Abstract

PURPOSE:To provide a novel diazodisulfone compound which generates an acid by the irradiation of KrF excimer laser beams, X rays, etc., and which has a large value on the formation of ultrafine patterns in a semiconductor industry, etc. CONSTITUTION:A compound of formula I (R1 is 3-8C branched or cyclic alkyl; R2 is 1-8C linear, branched or cyclic alkyl), e.g. bis(cyclohexyl sulfonyl) diazomethane. The compound has an excellent light transmitting property for far-UV rays, KrF excimer laser beams, ArF excimer laser beams, etc., readily generates an acid on the irradiation of light, electron beams, X rays, etc., and has excellent solution stability in resist materials. The compound of formula I is produced by reacting a compound of formula II with H2O2 and subsequently reacting the produced compound of formula III with tosylazide of formula IV in the presence of a base, the compound of formula II being produced by reacting a compound of formula RISH with CH2Cl2.

Description

[Detailed description of the invention] [Industrial application field]

[00011] The present invention relates to a diazodisulfone compound useful as a material sensitive to deep ultraviolet light, electron beams, X-rays, etc. For details, see KrF excimer laser light (248,4
This invention relates to a novel diazodisulfone compound that generates an acid upon irradiation with ArF excimer laser light (193 nm), electron beams, X-rays, etc.

[Conventional technology]

[0002] In recent years, with the high density integration of semiconductor devices, the light sources of exposure equipment used for microfabrication, particularly photolithography, have increasingly shorter wavelengths, and recently KrF excimer laser light (248.4 nm) has been considered. However, resist materials for using this KrF excimer laser light as a light source are required to react with high sensitivity to exposure. [0003] As one method for this purpose, it has been proposed to use a so-called chemically amplified resist material that increases sensitivity by containing a compound that generates acid upon exposure [H, Ito et al. ,Polym,En
g, Sci, vol. 23, p. 1012 (1983), etc.],
Compounds that generate acid upon exposure to light (hereinafter referred to as acid generators) include onium salts such as allyldiazonium salts, diallyliodonium salts, and triallylsulfonium salts (US Pat. No. 4,491,628).
No., Japanese Patent Publication No. 2-27660, U.S. Patent Publication No. 4,
603, 101, JP-A No. 62-115440, etc.) and 2,6-cyclopentyl base insect effects in Re5ist Technology.
and Processing V, p. 67 (198
8), etc.] have been reported. However, since all of these compounds used as acid generators have aromatic rings, they have the problem of reducing the light transmittance of resist materials containing them. Furthermore, in the case of onium salts, there is also the problem that resist materials containing them have poor solution stability during storage. [0004] Therefore, there are problems with the resist material itself due to the properties of the acid generator, such as poor stability of the resist material solution and resistance to far ultraviolet light and Kr.
The appearance of a practical acid generator that can overcome the problems such as insufficient transparency to F excimer laser light is currently awaited.

OBJECT OF THE INVENTION [0005] The present invention was made in view of the above-mentioned situation, and it uses light of 300 nm or less, such as deep ultraviolet light, Kr
It has high optical transparency to F excimer laser light, ArF excimer laser light, etc., and easily generates acid when exposed to the above exposure light source or irradiated with electron beams, X-rays, etc. It is an object of the present invention to provide an acid generator that has excellent solution stability and has the function of increasing the dissolution inhibition effect of resist materials.

[Structure of the invention]

[0006] The present invention comprises the following formula 1

[Formula 1] (wherein, R1 represents a branched or cyclic alkyl group having 3 to 8 carbon atoms, R2 is a straight chain having 1 to 8 carbon atoms,
Represents a branched or cyclic alkyl group. ) is an invention of a diazodisulfone compound represented by That is, the present inventors have discovered that light of 300 nm or less, such as deep ultraviolet light, particularly KrF
It has high optical transparency to excimer laser light, and easily generates acid by exposure with such an exposure light source or irradiation with electron beams, X-rays, etc., and the generated acid can chemically amplify the resist material by heating. As a result of intensive research in search of a new acid generator that acts effectively on the acid generator and has excellent solution stability in the resist material, it was found that the compound shown in Formula 1 above can achieve the purpose. Heading: The present invention has been completed. [0007] In the compound represented by formula 1 of the present invention,
Examples of R1 include is dipropyl group, dibutyl group, sec butyl group, tert-butyl group, is amyl group, se amyl group, 2-methylbutyl group, 2-
Methyl-2-butyl group, 1,1-dimethylbutyl group, 2
-hexyl group, 1,1-dimethylpentyl group, 1,1-
Dimethylhexyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group. Examples include branched or cyclic alkyl groups having 3 to 8 carbon atoms such as a cyclooctyl group, and R2 is, for example, a methyl group. Ethyl group, n-propyl group, 1so-propyl group, cyclopropyl group, n-butyl group, iso-dibutyl group 5
ec-butyl group, tert-butyl group, n-amyl group, 1so-amyl group, 5ec-amyl group, 2-methylbutyl group, 2-methyl-2-butyl group, 1,1-dimethylbutyl group, 2-hexyl groups, 1,1-dimethylpentyl group, 1,1-dimethylhexyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-peptyl group, cycloheptyl group, n-octyl group, cyclooctyl group, etc. Examples include 1 to 8 linear, branched, or cyclic alkyl groups. [0008] Specific examples of the compound represented by chemical formula 1 of the present invention include bis(cyclohexylsulfonyl)diazomethane, cyclohexylsulfonyl ethylsulfonyldiazomethane, bis(dipropylsulfonyldiazomethane), bis(tert-butyl sulfonyl)diazomethane, bis(sec-butylsulfonyl)diazomethane, tert-butylsulfonylmethylsulfonyldiazomethane, tert-butylsulfonylcyclohexylsulfonyldiazomethane, bis(cyclopentylsulfonyl)diazomethane, cyclopentylsulfonyl-tert
Examples include t-butylsulfonyldiazomethane and bis(amylsulfonyl)diazomethane. [0009] The compound of the present invention has R1 in chemical formula 1.
Since it has a bulky (bulky) group such as a branched or cyclic alkyl group in at least one of R2 and R2, it itself has a property of having low solubility in an alkaline developer. Therefore, a resist material containing it has a lower solubility in an alkaline developer and has an enhanced effect of inhibiting dissolution of unexposed areas, making it more preferable as a pattern forming material. . . [00101 On the other hand, in chemical formula 1, when R1 and R2 are different from the definition of the present invention and both are groups that are not bulky, for example, a compound where R1 and R2 are both ethyl groups, Kr
Although it has the property of generating acid when exposed to F excimer laser light, it also has the property of dissolving itself in the alkaline developer used in pattern formation. Therefore, when forming a pattern using a chemically amplified resist material that uses such a compound as an acid generator, both the exposed and unexposed areas will dissolve in the alkaline developer, resulting in poor performance. This results in the inability to form a pattern. [0011] The compound of the present invention can be easily synthesized, for example, as follows. That is, first, when R1=R2, it can be easily synthesized, for example, by the method of Formula 1 below.

[Formula 1] (In the formula, R1 and R2 are the same as above.) The method of Formula 1 is
More specifically, it is as follows. That is, first, chemical formula 2

[Image Omitted] A compound represented by 15H (in the formula, R1 is the same as above) and usually 1 to 20 mol, preferably 5 to 1 mol of the same compound.
~15 mol of dichloromethane, e.g. NaOH,
KOH, NaH, sodium methoxide, sodium ethoxide, pyridine, piperidine, morpholine, triethylamine. In the presence of a base such as N-methylpyrrolidine, alcohols such as methanol, ethanol, propatool, isopropanol, aromatic hydrocarbons such as benzene, toluene, etc., such as 1,4-dioxane, tetrahydrofuran (THF). in a solvent such as cyclic ethers, etc., usually at 20 to 100°C, preferably 25 to 65°C, usually
After reacting for ~20 hours, preferably 2~10 hours, chemical compound 3 is purified by a conventional method.

A compound represented by RISCH2SR1 (in the formula, R1 is the same as above) is obtained. Next, this compound and hydrogen peroxide, usually 1 to 10 mol, preferably 2 to 6 mol, per mol of this compound, are mixed in the presence of a catalyst such as sodium tungstate or ammonium phosphomolybdate, for example, water, For example, in a solvent such as an alcohol such as methanol, ethanol, propatool, isopropanol, or a mixed solvent of water and these alcohols, usually at a temperature of 0 to 100°C, preferably 20 to 80°C, and usually 1 to 20°C. time, preferably 1 to 1
After reacting for 0 hours, the compound 4 was purified by a conventional method.

A compound represented by RIS○2C)I2S○2R1 (wherein R1 is the same as above) is obtained. Furthermore, this compound and tosyl azide, usually 0.5 to 5 mol, preferably 0.5 to 2 mol, per mol of the compound, such as NaOH, KOH, NaH, sodium methoxide. For example water, for example methanol, ethanol, in the presence of a base such as sodium ethoxide, pyridine, piperidine, morpholine, triethylamine, N-methylpyrrolidine. Propatool, Isopropatool, Acetone, 1,4-
In a solvent such as a water-soluble organic solvent such as dioxane, or a mixed solvent of water and these water-soluble organic solvents, usually at 0 to 50 °C,
After reacting preferably at 5 to 30°C for usually 1 to 20 hours, preferably 1 to 10 hours, the reaction mixture is purified by a conventional method.

embedded image R: LSO2C802RI IYUKI2 (wherein R1 is the same as above) is obtained. [0012] Furthermore, when R1 and R2 are different, they can be easily synthesized, for example, by the method of Formula 2 below.

[Formula 2] (In the formula, R1 and R2 are the same as above. However, R1≠R2
゜) This method will be described in more detail as follows. That is, first, the compound represented by Chemical Formula 2 is added, and usually 0.5 to 10 mol, preferably 0.5 to 2 mol, per 1 mol of the compound.
Hydrochloric acid gas in an amount equal to or more than the mole of paraformaldehyde is introduced into a mixture of paraformaldehyde and paraformaldehyde, usually at a temperature of 10°C or lower, preferably -10 to 5°C, and then anhydrous calcium chloride is added thereto, and After reacting at 10°C or lower, preferably -10 to 5°C, for usually 1 to 20 hours, preferably 1 to 10 hours, the chemical compound 6 is purified by a conventional method.

A compound represented by RISCH2C1 (in the formula, R1 is the same as above) is obtained. Next, chemical formula 7

[Image Omitted] The compound represented by 2SH (in the formula, R2 is the same as above) is usually used in an amount of 0.5 to 5 mol, preferably 0.5 to 2 mol, per 1 mol of the compound. The compound represented by formula 6 is usually dissolved in an alcoholic solvent such as methanol, ethanol, isopropanol, etc. in the presence of a base such as NaOH, KOH, NaH, sodium methoxide, sodium ethoxide, etc. ~50℃, preferably 0~20℃, usually 1~20 hours, preferably 1~10 hours
After reacting for a period of time, the compound 8 is purified by a conventional method.

A compound represented by RISCH2SR2 (in the formula, R1 and R2 are the same as above) is obtained. This compound was oxidized and diazotized in the same manner as the compound represented by chemical formula 3 was oxidized and diazotized to give the compound shown in formula 1.

[Formula 1] (wherein, R1 and R2 are the same as above. However, R
1≠R2°) is obtained. [0013] Furthermore, the compound represented by Chemical Formula 8 can also be synthesized by the method shown in Formula 3.

[Formula 3] (In the formula, R1 and R2 are the same as above. However, R1≠R2
゜) That is, the compound represented by Chemical Formula 2, the compound represented by Chemical Formula 7 in an amount of usually 0.5 to 5 mol, preferably 0.5 to 2 mol per 1 mol of the same compound, and the compound represented by Chemical Formula 2. For example, NaOH, KOH, Na
H, sodium methoxide, sodium ethoxide, pyridine, piperidine, morpholine, triethylamine,
In the presence of a base such as N-methylpyrrolidine, alcohols such as methanol, ethanol, propatool, isopropanol, aromatic hydrocarbons such as benzene, toluene, etc., such as 1,4-dioxane, tetrahydrofuran (THF). in a solvent such as cyclic ethers, etc., usually at 20 to 100°C, preferably 25 to 65°C, usually
After reacting for up to 20 hours, preferably 2 to 10 hours, the compound represented by Chemical Formula 8 can be obtained by purifying the product by distillation, column chromatography, or the like. [0014] When synthesizing the compound of the present invention in which R1 and R2 are different, the method of Formula 2 is practically preferred.

[Effect]

[0015] To explain the action of the compound of the present invention, first, a chemically amplified resist material containing the compound of the present invention (a polymer having a property of becoming alkali-soluble by the action of an acid is used) is treated with KrF. When exposed to excimer laser light or the like, the compound of the present invention present in the exposed area generates acid according to the following formula 4.

[Formula 4] (In the formula, R1 and R2 are the same as above.) When heat treatment follows the exposure step, the functional groups of the resin undergo a chemical change with an acid according to the reaction formula of the following formula 5, and become alkali-soluble, and are developed. At this time, it will be eluted into the alkaline developer. (In the formula, n represents a positive integer.) On the other hand, since no acid is generated in the unexposed area, no chemical change occurs even after heat treatment, and no alkali-soluble groups are expressed. Further, since the compound of the present invention itself has a dissolution inhibiting effect, the unexposed area becomes poorly soluble in an alkaline developer. As described above, when pattern formation is performed using a chemically amplified resist material containing the compound of the present invention, a large difference in solubility in an alkaline developer occurs between exposed areas and unexposed areas. As a result, a positive pattern with good contrast is formed. Furthermore, as is clear from Equation 5 above, since the acid generated during exposure acts catalytically, exposure only needs to generate the necessary acid, making it possible to reduce the amount of exposure energy. [0016] It goes without saying that the compounds of the present invention are useful not only in semiconductor production but also as photosensitive reagents in applications that utilize photoreactions, such as photolithography and printing plate materials.

EXAMPLES The present invention will be explained in more detail below with reference to Examples and Reference Examples, but the present invention is not limited in any way by these. [0017] Reference example 1. Poly(p-tert-butoxystyrene-p
-Hydroxystyrene) synthesis (1) 2,2'-azobisisobutyronitrile as a catalyst was added to 17.6 g of p-tert-butoxystyrene in a toluene solvent under a nitrogen stream at 80°C for 6 hours. A polymerization reaction was carried out. After cooling the reaction solution, it was poured into methanol to cause 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 a white powder. (2) 15.0 g of poly(p-tert-butoxystyrene) obtained in the above (1) was dissolved in 1,4-dioxane, 10 ml of concentrated hydrochloric acid was added, and the mixture was stirred and refluxed for 1.5 hours. After cooling, the reaction solution was poured into water to cause crystallization, and the precipitated crystals were collected by filtration, washed with water, and dried under reduced pressure to obtain 11.8 g of poly(p-tert-butoxystyrene-p-hydroxystyrene) as a white powder. Obtained. p-tert- of the obtained polymer
The ratio of butoxystyrene units to p-hydroxystyrene units was approximately 1=1 as determined by IHNMR measurement. Average molecular weight: approximately 10,000 (GPC method: polystyrene standard). Reference example 2. Synthesis of p-toluenesulfonyl azide 22.5 g (0.35 mol) of sodium azide was dissolved in a small amount of water, and then diluted with 130 ml of 90% aqueous ethanol. Next, an ethanol solution of 60 g (0.32 mol) of p-toluenesulfonyl chloride was added dropwise at 10 to 25°C, and the mixture was reacted at room temperature for 2.5 hours. The reaction solution was then concentrated under reduced pressure, and the residual oil was washed with water several times and then dried over anhydrous magnesium sulfate. The desiccant was removed by filtration to obtain 50.7 g of p-)luenesulfonyl azide as a colorless oil.
'HNMR6ppm (heavy chloroform'): 2.4
3 (3H, s, methyl group), 7.24 (2H, d, J
=8Hz, aromatic ring 3-H, 5-H), 7°67 (2H
, d, J=8Hz, aromatic ring 2-H, 6-H). IR (Neat) cm-': 2120° [001
8] Example 1. Synthesis of bis(cyclohexylsulfonyl)diazomethane (1) An ethanol solution of 12.0 g (0.21 mol) of potassium hydroxide was soaked in 20.2 g (0.17 mol) of cyclohexylthiol at room temperature. The mixture was stirred at ±5°C for 30 minutes. Next, 18.2 g (2.14 mol) of dichloromethane was injected and the reaction was stirred at 50±5° C. for 6 hours. After standing overnight at room temperature, 55 ml of ethanol was poured into the reaction solution to dilute it, 400 mg of sodium tungstate was added, and 50 g (0.44 mol) of 30% hydrogen peroxide solution was added to the reaction solution.
It was added dropwise at 5 to 50°C, and the mixture was stirred and reacted at the same temperature for 4 hours. After the reaction, 200 ml of water was poured into the reaction solution, and the mixture was allowed to stand at room temperature overnight. The precipitated crystals were collected by filtration, washed with water, and dried to obtain 22 g of crude crystals.
was recrystallized from ethanol to obtain 15.5 g of bis(cyclohexylsulfonyl)methane as white needle-like crystals. Beat, 137-139°C. 'HNMRδppm (deuterochloroform): 1.1
3-2.24 (20H, m, cyclohexane ring methylene xlO), 3.52-3.66 (2H, m, cyclohexane ring methine X2), 4.39 (2H, s, methylene). IR (KBr) cnr': 1320.1305° (2) 1.7 g of sodium hydroxide was dissolved in 70 ml of 60% aqueous ethanol, and the bis(
cyclohexylsulfonyl)methane 12.1g (0,
04 mol) was added. Then, an ethanol solution of 8.2 g (0.04 mol) of p-toluenesulfonyl azide obtained in Reference Example 2 was added dropwise at 5 to 10°C, and after the addition, the mixture was stirred at room temperature for 7 hours. After standing overnight at room temperature, the precipitated crystals were collected by filtration, washed with ethanol, and dried. 11 g of the obtained crude crystals were recrystallized from acetonitrile to obtain 8.0 g of bis(cyclohexylsulfonyl)diazomethane as a pale yellow prism product. Ta. Beat at 130-131°C. 'HNMRδppm (deuterochloroform): 1.1
3-2.25 (20H, m, cyclohexane ring methylene xlO), 3.36-3.52 (2H, m, cyclohexane ring methine x 2). IR(KBr) car': 2130.1340.
1320° The obtained bis(cyclohexylsulfonyl)diazomethane was dissolved in acetonitrile and its ultraviolet spectral curve was measured. The results are shown in FIG. As is clear from the results in FIG. 1, the compound of the present invention, bis(cyclohexylsulfonyl)diazomethane, has almost no absorption in the vicinity of 300 to 24 Onm. [0019] Example 2. Synthesis of cyclohexylsulfonylethylsulfonyldiazomethane (1) Cyclohexylthiol 20.2g (0,17
mole) and 6.5 g of 80% paraformaldehyde (0.1
After introducing hydrogen chloride that had been dehydrated at -8 to 0°C, anhydrous calcium chloride was added and
Stir vigorously for an hour. The reaction solution was filtered and distilled under reduced pressure to obtain b
p, 100-b 16.5 g of lormethylcyclohexyl sulfide were obtained as a colorless oil. (2) An ethanol solution of 6 g (0.09 mol) of potassium hydroxide was added to 5.7 g (0.09 mol) of ethanethiol at a lower room temperature, and the mixture was stirred at the same temperature for 15 minutes. Then the above (
Chlormethylcyclohexyl sulfide 15 obtained in 1)
g (0.09 mol) was added dropwise at 10±5°C, and at the same temperature
The reaction was stirred for hours. After standing overnight at room temperature, 30 ml of ethanol and 30 ml of water were poured into the reaction solution to dilute it, 300 mg of sodium tungstate was added, and 53 g (0.47 mol) of 30% hydrogen peroxide was added dropwise at 45 to 50°C. The mixture was stirred and reacted at the same temperature for 6 hours. After the reaction, 300 ml of water was poured into the reaction solution, and the mixture was incubated overnight at room temperature. The precipitated crystals were collected by filtration, washed with water, and dried. 19 g of the crude crystals obtained were recrystallized from ethanol to give 15 cyclohexylsulfonyl ethyl sulfonylmethane. .5 g was obtained as white needles. Beat, 89-91°C. 'HNMR6ppm (heavy chloroform): 1.13
~2.24 (13H, m, cyclohexane ring methylene ×
5 and methyl group), 3.44 (2H, Q, J = 7.3
Hz, methylene), 3.53-3.68 (LH, m,
cyclohexane ring methine), 4.40 (2H,s, methylene). IR (KBr) car': 1315° (3) 1.7 g of sodium hydroxide in 70 ml of 60% aqueous ethanol
10.2 g (0.04
mol) was added. Next, an ethanol solution of 8.2 g (0.04 mol) of p-toluenesulfonyl azide obtained in Reference Example 2 was added dropwise at 5 to 10°C, and after the dropwise addition, the mixture was stirred at room temperature for 7 hours. After the reaction, 25ml of ethyl acetate was left overnight at room temperature.
The organic layer was extracted three times, and the separated organic layer was washed with water, dried (anhydrous magnesium sulfate), and then the solvent was distilled off. Concentrated residue 12g
Column chromatography [filling material: Wako gel C-2]
00 (Wako Tsumugi Kogyo Co., Ltd. trade name), eluent; n-hexane: ethyl acetate: methylene chloride = 8: 1: 0→
7:1:1] to obtain 4.1 g of cyclohexylsulfonylethylsulfonyldiazomethane as pale yellow crystals. Beat at 85-86.5°C. 'HNMRδppm (deuterochloroform): 1.1
3-2.27 (13H, m, cyclohexane ring methylene x 5 and methyl group), 3.38-3.54 (3H, m
, cyclohexane ring methine and methylene). IR (KBr) cm': 2120.1325°

Examples 3 to 5 Thiol compounds shown in Chemical Formula 2 in which R1 was each alkyl group shown in Table 1 were used as starting materials, and Example 1
The reaction and post-treatment were carried out in the same manner as above to obtain the corresponding bis(alkylsulfonyl)diazomethanes. The structure and physical properties of the obtained product are shown in Table 1.

[Table 1] Table 1 [0021] Examples 6 and 7 R1 and R2 of the thiol compounds shown in Chemical Formulas 2 and 7
Using each of the alkyl groups shown in Table 2 as starting materials, the reaction and post-treatment were carried out in the same manner as in Example 2 to obtain the corresponding diazomethane derivatives. The structure and physical properties of the obtained product are shown in Table 2.

[Table 2] Table 2 [0022] Comparative Examples 1 to 3゜Reactions and post-treatments were carried out in the same manner as in Example 1, except that various linear alkylthiols were used as the thiol compounds as starting materials, and the respective corresponding reactions were carried out in the same manner as in Example 1. Bis(alkylsulfonyl)diazomethane was obtained. Table 3 shows the structure and physical properties of the obtained product.
Shown below.

[Table 3] Table 3 [0023] Comparative example 4. Synthesis of bis(methylsulfonyl)diazomethane (1) Methylmethylsulfinylmethylsulfide 7
．． 0 g (0°06 mol) in methanol 40 ml and water 4
Sodium tungstate 140ml dissolved in ml
After adding 21g of 30% hydrogen peroxide solution (0.19g)
mol) was added dropwise at 45 to 50°C, followed by stirring and refluxing for 8 hours. The reaction solution was poured into 400 ml of water at room temperature overnight, and the precipitated product was collected by filtration, washed with water, and dried to obtain crude crystals9.
5 g was recrystallized from ethanol to obtain 7.8 g of bis(methylsulfonyl)methane as white flaky crystals. Beating, 148-149.5°C. 'HNMR6ppm (heavy chloroform): 3.26
(6H,s, methyl group x2), 4.43(2H,s,
methylene). IR (KBr) cm-': 1310° (2) 7.5 g of bis(methylsulfonyl)methane obtained in (1) above
(0.04 mol) as a raw material, the reaction and post-treatment were carried out in the same manner as in Example 1 (2) to obtain 5 g of crude crystallized bis(methylsulfonyl)diazomethane, which was subjected to column chromatography (filling material; Wakogel C-200, eluent; n-hexane: ethyl acetate = 8:1 → 4:1 → 3:1
) to obtain 2.5 g of bis(methylsulfonyl)diazomethane as white crystals. Beat at 120-124°C. 'HNMRδppm (deuterochloroform): 3.3
7 (6H, s, methyl group x 2). IR (KBr) cnr': 2145.1335.
1320° [0024] Application Example 1° A resist material having the following composition was prepared. Poly(p-tert-butoxystyrene-p-hydroxystyrene) (polymer of Reference Example 1)
6.0g bis(cyclohexylsulfonyl)diazomethane (acid generator: compound of Example 1) 0.3g diethylene glycol dimethyl ether 1
3.7g A pattern forming method using the above resist material will be explained with reference to FIG. The resist material 2 was spin-coated onto a substrate 1 such as a semiconductor, and after soft baking on a hot plate at 90° C. for 90 seconds, a resist material film with a thickness of 1.0 μm was obtained (FIG. 2(a)). Then 248.4a
The film was selectively exposed to KrF excimer laser light 3 of m through a mask 4 (FIG. 2(b)). and 110℃, 90
After baking on a hot plate for seconds, add alkaline developer (2,
38% tetramethylammonium hydroxide aqueous solution)
By developing for 60 seconds with
Figure (C)). At this time, the aspect ratio of the positive pattern was approximately 87 degrees with a well-shaped 0.3 μm line and space (
It had a resolution of 0.3 μmL/S), and the exposure energy amount was about 25 mJ/cm 2 . [0025] Application Examples 2 to 7°A resist material was prepared in the same manner as in Application Example 1, except that the diazodisulfone compounds of the present invention obtained in Examples 2 to 7 were used as acid generators, respectively. A pattern was formed on the semiconductor substrate in the same manner as above. The results are shown in Table 4.

Table 4 As is clear from the results in Table 4, it is possible to form a good positive pattern by using a resist material containing the compound of the present invention as an acid generator. [0026] Reference Examples 3 to 6° Resist materials were prepared in the same manner as Application Example 1, except that the bis(linear alkylsulfonyl)diazomethane obtained in Comparative Examples 1 to 4 was used as the acid generator, respectively. When a pattern was formed on a semiconductor substrate in the same manner as in Application Example 1, the unexposed areas were also dissolved during development, making it impossible to form a positive pattern. As is clear from the above, the bulky alkyl group introduced into at least one of R1 and R2 in the compound of the present invention is important in expressing the dissolution inhibiting effect of the compound of the present invention in an alkaline developer. It is clear that they play a role.

【Effect of the invention】

[0027] As is clear from the above description, the resist material containing the diazodisulfone compound of the present invention as a constituent component is used with a light source of 300 nm or less, such as deep ultraviolet light (DEE).
p U■), for example, KrF excimer laser light (248
, 4am), etc., a fine pattern with a good shape on the order of submicrons can be easily obtained. Therefore, the present invention has great value for the formation of ultra-fine patterns in the semiconductor industry and the like. [0028] The compound of the present invention is particularly effective as an acid generator during exposure to far ultraviolet light or KrF excimer laser light, but it can also be used satisfactorily with ArF excimer laser light, electron beams, X-rays, etc.

[Brief explanation of the drawing]

[00291] FIG. 1 shows an ultraviolet spectral curve diagram of the acetonitrile solution of bis(cyclohexylsulfonyl)diazomethane obtained in Example 1.

[Figure 2]

FIG. 2 is a process sectional view of a positive pattern forming method using a resist material containing the compound of the present invention as an acid generator.

[Explanation of symbols]

[0031] 1... Substrate, 2... Resist material film containing the compound of the present invention, 3... KrF excimer laser light, 4... Mask, 2a... Resin pattern.

[Figure 1]

[Figure 2]

Claims (1)

[Claims] Claim 1: The following formula 1 [Formula 1] (wherein, R1 represents a branched or cyclic alkyl group having 3 to 8 carbon atoms, and R2 represents a linear or branched alkyl group having 1 to 8 carbon atoms. or a cyclic alkyl group).