JPH1135573A - New bissulfonyldiazomethane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new compound which is excellent in the contrast between the exposure part and the unexposured part when used as an acid generator of chemical amplification type resist and can show a high residual film ratio. SOLUTION: This compound is bissulfonyldiazomethane of formula I [R is each H or a group forming dimethylmethylene group with two R in the same ring; (n) is 0 or 1], e.g. a bis[2-(2 -tetrahydropyranyl) oxycyclo-hexyl -sulfonyl] diazomethane of formula II. The compound of formula I (R is H) can be obtained by reacting bis(hydroxycyclohexyl)-sulfonyldiazomethane with 3,4 -dihydro-2H -pyran. The compound of formula obtained thus has properties generating an acid by irradiation of light and dissociating tetrahydropyranyloxy group by the generated acid.

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 poor contrast between exposed and unexposed portions, and therefore have the disadvantage that the residual film ratio is low.

[0006]

SUMMARY 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 high residuals. The object of the present invention is to provide a novel bissulfonyldiazomethane having a film ratio.

[0007]

DISCLOSURE OF THE INVENTION The present inventors have developed a novel bissulfonyl compound which, when used as an acid generator for a chemically amplified resist, has excellent contrast between exposed and unexposed areas and exhibits a high residual film ratio. As a result of intensive studies to develop a diazomethane compound, they have found that a compound having two tetrahydropyranyloxy-substituted alicyclic groups can achieve the object, and based on this finding, the present invention I've reached the point.

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

Embedded image (Wherein R is a hydrogen atom or a group forming a dimethylmethylene group with two Rs in the same ring,
n is 0 or 1).

The alicyclic group in the general formula (I) is a cyclohexyl group when two Rs are hydrogen atoms, and a cyclohexyl group when two Rs together form a dimethylmethylene group. Is a 7,7-dimethylbicyclo [2.2.1] heptyl group. The tetrahydropyranyloxy group bonded to the alicyclic group may be bonded to any of the 2-position, 3-position and 4-position.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the compounds of the present invention, when R in the above general formula (I) is a hydrogen atom, that is, when the alicyclic group is a cyclohexyl group, for example, according to the following reaction formula: , Bis (hydroxycyclohexyl) sulfonyldiazomethane or bis (hydroxycyclohexylmethyl) sulfonyldiazomethane (II) with 3,4-dihydro-2H-pyran (III).

[0011]

Embedded image (N in the formula has the same meaning as described above)

This reaction is carried out in an inert solvent such as a cyclic ether such as tetrahydrofuran or dioxane in the presence of pyridinium p-toluenesulfonate. Further, when two Rs in the same ring of the general formula (I) form a dimethylmethylene group, that is, a 7,7-dimethylbicyclo [2.2.1] heptyl group,
The corresponding hydroxy-substituted alicyclic mercaptan (IV) and methylene halide (V) are condensed to form the corresponding bis (hydroxy-substituted alicyclic thio) methane (VI) according to the following reaction formula, which is then oxidized. To give the corresponding bissulfonylmethane (VII), followed by diazotization to produce bis (hydroxy-substituted alicyclic sulfonyl) diazomethane (VIII), to which 3,4-dihydro-
It can be obtained by reacting 2H-pyran (III).

[0013]

Embedded image (Where X is a halogen atom and n has the same meaning as described above)

Examples of the methylene halide (V) used in this reaction include methylene chloride, methylene bromide and methylene iodide. In the above reaction formula, the hydroxy-substituted alicyclic mercaptan (I
The condensation of V) with methylene halide is carried out in an inert solvent such as ethanol in the presence of a base such as potassium hydroxide.

Next, the reaction of oxidizing the bis (hydroxy-substituted alicyclic thio) methane (VI) thus obtained into the corresponding bissulfonylmethane (VII) is carried out by an inert reaction such as ethanol. In a solvent, the reaction can be carried out with hydrogen peroxide using alkali tungstate as a catalyst.

Further, the diazotization of bissulfonylmethane (VII) thus converted can be carried out, for example, by converting tosyl azide in an inert solvent such as ethanol in the presence of a base such as potassium hydroxide or sodium hydroxide. It is performed by reacting. And the last bis (hydroxy-substituted alicyclic sulfonyl) diazomethane (VII
The reaction between I) and 3,4-dihydro-2H-pyran (III) is carried out in the presence of pyridinium p-toluenesulfonate, as in the case of the cyclohexyl group. 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 that has not been published in the literature, and generates an acid upon irradiation with light,
It has the property that the tetrahydropyranyloxy group is dissociated by the generated acid.

[0018]

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

Example 1 5 g (0.014 mol) of bis (2-hydroxycyclohexylsulfonyl) diazomethane and 3,4-dihydro-
3.5 g (0.042 mol) of 2H-pyran was dissolved in 50 g of dioxane, and 0.1 g of pyridinium p-toluenesulfonate was added, followed by stirring at room temperature for 40 hours. Then
After adding 50 g of water and extracting with 30 g of ethyl acetate, the solvent was distilled off, and the resulting product was further decomposed and purified by silica gel column chromatography, whereby the formula was obtained.

Embedded image Bis [2- (2-tetrahydropyranyl) represented by
[Oxycyclohexylsulfonyl] diazomethane 2.0
g was obtained. Its infrared absorption spectrum and proton nuclear magnetic resonance spectrum are shown in FIGS. 1 and 2.

Example 2 30 g (0.53 mol) of potassium hydroxide was added to ethanol 3
00 g, and add mercaptoisoborneol 6
0 g (0.32 mol) were added. Then, 28 g (0.16 mol) of methylene bromide was added dropwise at room temperature over 30 minutes. After further stirring the reaction mixture at 50 ° C. for 3 hours, the precipitated potassium bromide was filtered off, then neutralized with dilute hydrochloric acid, and further 500 g of methylene chloride was added.
, And the solvent is distilled off, and bis [2-hydroxy-7,7
-Dimethylbicyclo [2.2.1] heptanylmethylthio] methane (67 g) was obtained as a yellow oil. Then, 67 g of this bis [2-hydroxy-7,7-dimethylbicyclo [2.2.1] heptanylmethylthio] methane
(0.17 mol) was dissolved in 300 g of ethanol, and 0.6 g of sodium tungstate was added. In addition, 35
200 g (2.06 mol) of a 20% aqueous hydrogen peroxide solution were added dropwise at 45 ° C. over 30 minutes. The reaction mixture was further stirred at 50 ° C. for 20 hours. Then, 1000 g of water
Was added to obtain 51 g of precipitated bis [2-hydroxy-7,7-dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] methane as white crystals. Next, the bis [2-hydroxy-7,7-dimethylbicyclo [2.
2.1] Heptanylmethylsulfonyl] methane 20g
(0.045 mol) and 10 g of tosyl azide (0.051
Mol) was dissolved in 80 g of ethanol, and 300 g (0.53 mol) of a 10% aqueous potassium hydroxide solution was added at room temperature to 3 g.
It was added dropwise over 0 minutes. The reaction mixture was further stirred at room temperature for 2 hours. Then, the precipitated crystals are collected by filtration,
6.5 g of bis [2-hydroxy-7,7-dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] diazomethane were obtained.

The bis [2-hydroxy-7,7-dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] diazomethane thus obtained, 5.0 g (0.011
Mol) and 2.9 g of 3,4-dihydro-2H-pyran
(0.033 mol) was dissolved in 50 g of dioxane.
0.1 g of pyridinium toluenesulfonate was added, and the mixture was stirred at room temperature for 40 hours. Next, 50 g of water was added, and the mixture was extracted with 30 g of ethyl acetate. The solvent was distilled off, and the residue was separated and purified by silica gel column chromatography to obtain the compound of the formula

Embedded image Bis [2- [2-tetrahydropyranyl] represented by
1.5 g of oxy-7,7-dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] 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 parts by weight of bis [2- (2-tetrahydropyranyl) oxycyclohexylsulfonyl] diazomethane obtained in Example 1 or bis [obtained in Example 2 as an acid generator in 100 parts by weight of the resin mixture containing 7 parts by weight. Compounding 7 parts by weight of 2- [2-tetrahydropyranyl] oxy-7,7-dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] diazomethane, 0.3 part by weight of triethylamine and 0.2 part by weight of salicylic acid Was dissolved in 490 parts by weight of propylene glycol monomethyl ether acetate, and this 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, bis (cyclohexylsulfonyl), a known acid generator, is used.
Physical properties of the positive resist composition using 5 parts by weight of diazomethane were determined, and the results are shown in Table 1.

(1) Sensitivity: A 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 as 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 operations up to exposure, after standing for 60 minutes, PEB treatment and development were performed 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 determined as a ratio of the film thickness after development to the film thickness before development.

[0028]

[Table 1]

[0029]

The compound of the present invention is a novel compound, and when it is used as an acid generator of a chemically amplified resist, the contrast between exposed and unexposed areas is excellent, so that the residual film ratio is high and the profile shape is excellent. Give the pattern.

[Brief description of the drawings]

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

FIG. 2 is a proton 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 Daitomix Mix Co., Ltd. (72) Inventor Norio Hayakawa 7-fukushima, Fukushima-ku, Osaka-shi, Osaka 15-26 Daitomix Mix Co., Ltd.

Claims (3)

[Claims] 1. A compound of the general formula (Wherein R is a hydrogen atom or a group forming a dimethylmethylene group with two Rs in the same ring,
n is 0 or 1). 2. The compound according to claim 1, wherein R in the general formula is a hydrogen atom.
The bissulfonyldiazomethane as described. 3. The compound according to claim 1, wherein two Rs in the same ring in the general formula each form a dimethylmethylene group.
The bissulfonyldiazomethane as described.