JPH1135551A - New sulfonyldiazomethane compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the new subject compound useful as an acid generating agent in a chemically amplifying type resist manifesting a sufficient sensitivity and resolution. SOLUTION: The objective compound is a sulfonyldiazomethane of formula I (R<1> is a lower alkylene; R<2> is a tertiary alkyl), e.g. bis(4-tert -butoxycarbonylmethyloxyphenylsulfonyl) diazomethane. The compound of formula I is obtained by condensing thiophenol with a methylene halide such as methylene chloride and methylene bromide in an inert solvent by using a dehydrohalogenation agent to provide bis(hydroxyphenylthio) methane, oxidizing the obtained bis(hydroxyphenylthio) methane to provide bis(hydroxyphenylsulfonyl) methane of formula II, reacting a tertiary alkyl ω-halogenoalkanate with the obtained bis(hydroxyphenylsulfonyl) methane, and diazotizing the product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel sulfonyldiazomethane compound suitable as an acid generator for a chemically amplified resist.

[0002]

2. Description of the Related Art In recent years, in the production of semiconductor devices and liquid crystal devices, chemically amplified resist compositions have been used. This chemically amplified resist composition is a resist utilizing the catalytic action of an acid generated by irradiation with radiation, and has high sensitivity and resolution, and a compound that generates an acid upon irradiation with radiation, that is, an acid generator. This has the advantage that the amount of used may be small.

[0003] There are two types of chemically amplified resists, a positive type and a negative type. These are generally an acid generator and a film-forming component whose solubility in an aqueous alkali solution changes due to the action of the generated acid. Is the basic component.

In the positive resist, as a film-forming component, polyhydroxystyrene or the like in which a part of hydroxyl groups is protected by a dissolution inhibiting group such as a tert-butoxycarbonyl group or a tetrahydropyranyl group is used. In a negative resist, as a film-forming component, a resin component such as polyhydroxystyrene or a polyhydroxystyrene or a novolak resin in which a part of a hydroxyl group is protected by the above-described dissolution inhibiting group is usually added to an acid such as a melamine resin or a urea resin. A combination of crosslinkable substances is used.

As such an acid generator, certain diazomethane compounds have been used (JP-A-3-103854, JP-A-4-210960, JP-A-4-217249). Resist compositions using these have the disadvantage that the contrast between the exposed and unexposed areas is poor and satisfactory sensitivity is hardly obtained.

[0006]

DISCLOSURE OF THE INVENTION The present invention overcomes the drawbacks of the conventional diazomethane compound, and when used as an acid generator for a chemically amplified resist, provides excellent contrast between exposed and unexposed areas and provides a sufficient contrast. The object of the present invention is to provide a novel sulfonyldiazomethane compound exhibiting sensitivity.

[0007]

Means for Solving the Problems The present inventors have developed a novel diazomethane compound which has excellent contrast between exposed and unexposed areas and shows sufficient sensitivity when used as an acid generator of a chemically amplified resist. As a result of intensive research for the development, it is possible to achieve the object by using a compound in which a tertiary alkoxycarbonylalkoxy group is introduced as an acid-dissociable group into two phenyl groups of bisphenylsulfonyldiazomethane. And found the present invention based on this finding.

That is, the present invention provides a compound represented by the general formula

Embedded image (Wherein R ¹ is a lower alkylene group and R ² is a tertiary alkyl group).

The lower alkylene group of R ¹ in the general formula (I) is an alkylene group having 1 to 4 carbon atoms, which may be linear or branched. Examples of such a lower alkylene group include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, an isopropylene group, and an isobutylene group. Examples of the tertiary alkyl group of R ² in the general formula (I) include a tertiary alkyl group having 4 to 8 carbon atoms, such as a tertiary butyl group, a tertiary pentyl group, and a 1,1-dimethylbutyl group. Can be mentioned.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The compound of the present invention is prepared by condensing thiophenol (II) with methylene halide (III) to form bis (hydroxyphenylthio) methane (IV) according to, for example, the following reaction formula. This is then oxidized to produce bis (hydroxyphenylsulfonyl) methane (V), which is reacted with a tertiary alkyl ω-halogenoalkanoate (VI), and then diazotized,
Alternatively, it can be produced by diazotizing bis (hydroxyphenylsulfonyl) methane and then reacting with tertiary alkyl ω-halogenoalkanoate.

[0011]

Embedded image (However, X and X 'are halogen atoms)

Examples of the methylene halide (III) used in this reaction include methylene chloride, methylene bromide and methylene iodide. Examples of the tertiary alkyl ω-halogenoalkanoate (VI) include tert-butyl esters of chloroacetic acid, bromoacetic acid, 3-chloropropionic acid, 3-bromopropionic acid, 4-chlorobutyric acid and 4-bromobutyric acid. Tertiary pentyl ester or 1,1-dimethylbutyl ester.

In the above reaction formula, thiophenol (I
The condensation of I) with methylene halide (III) is carried out in an inert solvent such as acetone using a dehydrohalogenating agent such as a combination of a quaternary ammonium salt such as tetrabutylammonium halide and alkali carbonate.

Next, the reaction of oxidizing the bis (hydroxyphenylthio) methane (IV) thus obtained to produce the corresponding bis (hydroxyphenylsulfonyl) methane (V) is carried out by using a reaction such as ethanol. The reaction can be carried out with hydrogen peroxide in an active solvent using alkali tungstate as a catalyst.

The reaction for introducing a tertiary alkoxycarbonylalkoxy group into bis (hydroxyphenylsulfonyl) methane (V) or its diazotized product (VIII) is carried out in an inert solvent such as dimethylformamide such as alkali carbonate. The reaction can be carried out by reacting a tertiary alkyl (VI) ω-halogenoalkanoate in the presence of an alkali.

Furthermore, the diazotization of bis (hydroxyphenylsulfonyl) methane (V) or its tertiary alkoxycarbonylalkoxylate (VII) can be carried out in an inert solvent such as ethanol in the presence of a tertiary amine such as triethylamine. The reaction is carried out. The product thus obtained can be purified by means such as recrystallization according to a conventional method.

The thus obtained general formula (I)
Is a novel compound not described in any literature, and has a property of generating an acid upon irradiation with light.

[0018]

Next, the present invention will be described in more detail by way of examples.

Example 1 50 g (0.40 mol) of 4-hydroxybenzenethiol and 1.5 g of tetrabutylammonium bromide
(0.006 mol) was dissolved in 250 g of acetone, and 43 g (0.31 mol) of potassium carbonate was added thereto. Next, 40 g (0.23 mol) of methylene bromide was added at 45 ° C.
For 30 minutes. The mixture was further stirred at 45 ° C. for 8 hours, and the precipitated potassium bromide was separated by filtration. The solvent was distilled off at 40 ° C. under vacuum. Then, 500 g of water was added to the obtained product, and 600 g of ethyl acetate was added.
After extraction with, the solvent was distilled off to obtain bis (4-hydroxyphenylthio) methane as a yellow oil.

Next, 50 g (0.19 mol) of the bis (4-hydroxyphenylthio) methane was added to ethanol 27.
5 g of sodium tungstate (0.0 g).
2g) was added. 162 g of 35% hydrogen peroxide solution
(1.67 mol) was added dropwise at 50 ° C. over 1 hour. The reaction mixture was further stirred at 50 ° C. for 5 hours. Next, the mixture was neutralized with a 30% aqueous sodium hydroxide solution, and the precipitated crystals were collected by filtration. In this way, screw (4
-Hydroxyphenylsulfonyl) methane was obtained as white crystals.

Next, 30 g (0.09 mol) of this bis (4-hydroxyphenylsulfonyl) methane was dissolved in 160 g of dimethylformamide, and 28 g of potassium carbonate was dissolved.
(0.20 mol) was added. Chloroacetic acid tert
30 g (0.20 mol) of -butyl were added dropwise at room temperature over 30 minutes. The mixture was further stirred at 80 ° C. for 3 hours, cooled to room temperature, potassium carbonate was filtered off, washed with 1200 g of diluted hydrochloric acid, and bis (4-t
42.0 g of tert-butoxycarbonylmethyloxyphenylsulfonyl) methane were obtained as a yellow oil.

Finally, 30 g (0.054 mol) of this bis (4-tert-butoxycarbonylmethyloxyphenylsulfonyl) methane and 15 g of tosyl azide (0.
076 mol) was dissolved in 300 g of ethanol, and 12.5 g (0.12 mol) of triethylamine was dissolved at room temperature in 3 g.
It was added dropwise over 0 minutes. The mixture was further stirred at room temperature for 1.5 hours, and the precipitated crystals were collected by filtration. The obtained final product was repeatedly recrystallized from acetonitrile to obtain the desired product, bis (4-tert-butoxycarbonylmethyloxy). Phenylsulfonyl) diazomethane 1
3.0 g were obtained. The melting point of the compound was 98 ° C and the decomposition point was 114 ° C. 1 and 2 show an infrared absorption spectrum and a proton nuclear magnetic resonance spectrum of this compound.

Example 2 Bis (4-hydroxyphenylsulfonyl) methane was prepared in the same manner as in Example 1, and tert-chloroacetic acid was added thereto.
3-chloropropionic acid ter in place of 30 g of -butyl
Using 33 g of t-butyl and the same operation, 13.5 g of bis (4-tert-butoxycarbonylethyloxyphenylsulfonyl) diazomethane was obtained.

Reference Example A weight-average molecular weight of 10,000 wherein 39 mol% of hydrogen atoms of a hydroxyl group is substituted by a tert-butyloxycarbonyl group.
Polyhydroxystyrene of 0 and 39 of the hydrogen atom of the hydroxyl group
Mol% of polyhydroxystyrene having a weight average molecular weight of 10,000 substituted by an ethoxyethyl group in a weight ratio of 3:
7, 5 parts by weight of bis (4-tert-butoxycarbonylmethyloxyphenylsulfonyl) diazomethane obtained in Example 1 as an acid generator, 0.3 part by weight of triethylamine, and 0.1 part by weight of salicylic acid in 100 parts by weight of a resin mixture containing 7 parts by weight. 2 parts by weight were dissolved in 490 parts by weight of propylene glycol monomethyl ether acetate, and the solution was filtered through a membrane filter having a pore size of 0.2 μm to prepare a positive resist composition. Next, physical properties of the positive resist composition were determined by the following methods, and the results are shown in Table 1. For comparison, the physical properties of a positive resist composition using 5 parts by weight of a known acid generator, bis (cyclohexylsulfonyl) diazomethane, were determined, and the results are also shown in Table 1.

(1) Sensitivity: The sample was applied on a silicon wafer using a spinner and dried on a hot plate at 90 ° C. for 90 seconds to obtain a 0.7 μm-thick resist film. This film has a reduced projection exposure apparatus NSR-2005E
Exposure was performed using X8A (manufactured by Nikon Corporation) at a dose of 1 mJ / cm ² , followed by PE at 110 ° C. for 90 seconds.
B (POST EXPOSURE BAKE)
When developed with an aqueous solution of 2.38% by weight of tetramethylammonium hydroxide at 23 ° C. for 60 seconds, washed with water for 30 seconds and dried, the minimum exposure time at which the film thickness of the exposed area after development becomes 0 is defined as mJ / It was measured in cm ² (energy amount).

(2) Resolution: The same operation as in the above (1) was performed, and the resolution was shown by the limit resolution at the exposure amount for reproducing a mask pattern of 0.25 μm.

(3) Resist pattern shape: (1)
The same operation as that described above was performed, and a case where a 0.25 μm rectangular resist pattern was obtained was evaluated as ○, and a case where the top of the resist pattern became a slightly thin pattern or a wavy resist pattern was evaluated as x.

(4) Stability after pulling out: In the above (1), after performing the operation up to exposure, after standing for 60 minutes, PEB treatment and development were carried out in the same manner to give 0.25 μm.
The cross-sectional shape of the resist pattern was observed with a SEM (scanning electron microscope) photograph, and the line and space of 0.25 μm were formed 1: 1, and the line width (resist pattern width) was 0.25 μm. The case where the width became wider and the space width became narrower than 0.25 μm was evaluated as 3, the case where no resolution was obtained was evaluated as 1, and the middle of each was evaluated as 4, 2.

(5) Residual film ratio: The same operation as in the above (1) was performed, and the residual film ratio of the unexposed portion was shown as a ratio of the film thickness after development to the film thickness before development.

[0030]

[Table 1]

[0031]

The compound of the present invention is a novel compound. When this compound is used as an acid generator of a chemically amplified resist, the contrast between exposed and unexposed portions is good, so that the residual film ratio is high and the profile shape is low. Give a good pattern. Further, the compound of the present invention has an advantage that the tertiary alkyl group is cleaved by an acid and a carboxylic acid is generated from the residue, so that the compound exhibits high sensitivity.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of the compound obtained in Example 1.

FIG. 2 is a diagram showing a ⁺ H nuclear magnetic resonance spectrum of the compound obtained in Example 1.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiharu Shimaki 7-15-26 Fukushima-ku, Fukushima-ku, Osaka-shi, Osaka Inside Daitomix Mix Co., Ltd. (72) Inventor Nobuya Kuromoto 7-chome, Fukushima-ku, Osaka-shi, Osaka 15-26 Daito Mix Inc.

Claims (3)

[Claims] 1. A compound of the general formula (Wherein R ¹ is a lower alkylene group and R ² is a tertiary alkyl group). 2. The sulfonyldiazomethane compound according to claim 1, wherein R ¹ is a methylene group. 3. The sulfonyldiazomethane compound according to claim 1, wherein R ² is a tertiary butyl group.