JPH1135552A - New diazomethane compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the new subject compound useful as an acid generating agent for a chemically amplifying type resist good in resolution, pattern form and rate of a remaining membrane. SOLUTION: This diazomethane compound is the one of formula I [each R is H or forms dimethylmethylene group by binding two Rs in the same ring; R<1> and R<2> are each a lower alkyl; (n) is 0 or 1], e.g. bis[2-(1 -ethoxyethyloxy) cyclohexysulfonyl] diazomethane. The compound of formula I is obtained by reacting a thiol compound with a methylene halide in a solvent such as ethanol in the presence of a hydrogen halide scavenger such as an alkali hydroxide to provide a compound of formula II, oxidizing the obtained compound of formula II with an oxidizing agent such as hydrogen peroxide to provide a bissulfonylmethane body, diazotizing the bissulfonylmethane body to provide a bissulfonyldiazomethane body, reacting the bissulfonyldiazomethane body with an alkoxyalkene by using a catalyst such as pyridinium p-toluenesulfonate, and separating and purifying the product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel diazomethane compound having a sulfonyl group, which is 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). A resist composition using these has a disadvantage that the contrast between an exposed part and an unexposed part is inferior, so that the residual film ratio is not sufficient.

[0006]

The present invention overcomes the drawbacks of the conventional diazomethane compound and, when used as an acid generator in a chemically amplified resist, provides excellent contrast between exposed and unexposed areas. It is an object of the present invention to provide a novel diazomethane compound capable of providing a resist pattern having improved resolution and pattern shape and obtaining a chemically amplified resist exhibiting a high residual film ratio.

[0007]

The present inventors have conducted intensive studies to develop a novel diazomethane compound having the above-mentioned excellent functions, and as a result, have found that a cyclohexane ring having a lower alkoxyalkoxy group or a 7,7-layer. Based on this finding, they have found that bissulfonyldiazomethane having a specific structure having a dimethyl-bicyclo [2.2.1] heptane ring at both ends is a novel compound which has not been described in the literature and can be used for the purpose. The present invention has been completed.

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

Embedded image (R in the formula is a hydrogen atom or a group forming a dimethylmethylene group by two Rs in the same ring;
R ¹ and R ² are each a lower alkyl group, and n is 0 or 1).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The diazomethane compound of the present invention
A lower compound represented by R ¹ and R ² in the general formula (I), which is a novel compound represented by the general formula (I) and not described in the literature, is a methyl group, an ethyl group, an n
-Propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group and the like. R ¹ and R ² may be the same or different. Also, R ² OCH
As (R ¹ ) O—, a 1-ethoxyethyloxy group is preferred from the viewpoint of performance as an acid generator and ease of synthesis.

In the above general formula (I), when each R is a hydrogen atom,

Embedded image (Wherein R ¹ , R ² and n have the same meanings as described above), while when R forms a dimethylmethylene group with two Rs in the same ring,

Embedded image (Wherein R ¹ , R ² and n have the same meaning as described above).

The diazomethane compound represented by the general formula (I) is suitable as an acid generator for a chemically amplified resist. When this compound is used as an acid generator, the contrast between an exposed portion and an unexposed portion is excellent. , The resulting resolution,
A chemically amplified resist exhibiting an improved pattern shape and residual film ratio (unexposed portion in the case of a positive type, exposed portion in the case of a negative type), and sufficient sensitivity can be obtained.

The diazomethane compound represented by the above general formula (I) is, for example, a compound represented by the following reaction formula:

Embedded image (Wherein R ³ is a group obtained by removing one hydrogen atom from R ¹ ,
¹ , R ² and n have the same meaning as described above).

That is, first, the thiol compound (II)
And methylene halide (III) in a solvent such as an alcohol such as methanol or ethanol or an aromatic hydrocarbon such as toluene in the presence of a hydrogen halide scavenger to give a compound represented by the general formula (IV). The obtained compound is oxidized with an oxidizing agent such as hydrogen peroxide to obtain a bissulfonylmethane compound (V). Then
This bissulfonylmethane compound (V) is diazotized with a diazotizing agent such as tosyl azide in a solvent such as an alcohol such as methanol or ethanol or an aromatic hydrocarbon such as toluene to give the bissulfonyldiazomethane compound (VI). obtain. Finally, the bissulfonyldiazomethane (VI) is reacted with an alkoxyalkene represented by the general formula (VII) in a solvent such as an ether such as dioxane, and the product is separated by a known method. By refining, the desired diazomethane compound represented by the general formula (I) is obtained.

Examples of the methylene halide (III) used in this reaction include methylene chloride, methylene bromide and methylene iodide. In addition, as the hydrogen halide scavenger used in this reaction,
Alkali hydroxide and the like are preferred.

When the compound represented by the general formula (IV) is oxidized with hydrogen peroxide to be converted into the corresponding bissulfonylmethane compound (V), it is advantageous to use a catalyst such as an alkali tungstate. is there. When the bissulfonylmethane compound (V) is diazotized with tosyl azide to be converted into the corresponding bissulfonyldiazomethane compound (VI), diazotization is usually performed in the presence of an alkali such as an alkali hydroxide. Further, in the reaction of adding the alkoxyalkene represented by the general formula (VII) to the hydroxyl group of the bissulfonyldiazomethane compound (VI), it is preferable to use a catalyst such as pyridinium p-toluenesulfonate.

The thus-obtained general formula (I)
The diazomethane compound represented by the formula (1) can be mixed with a film-forming component as an acid generator to prepare a chemically amplified resist composition. An appropriate amount to be added at this time is 0.5 to 20 parts by weight based on 100 parts by weight of the film forming component.

[0017]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The physical properties of the positive resist composition were determined as follows.

(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. The film was exposed at a dose of 1 mJ / cm ² by using a reduction projection exposure apparatus NSR-2005EX8A (manufactured by Nikon Corporation), and then heated at 110 ° C. for 90 seconds, and then 2.38% by weight.
23 ° C with tetramethylammonium hydroxide aqueous solution
For 60 seconds, washed with water for 30 seconds, and dried. At this time, the minimum exposure time at which the film thickness of the exposed portion after development became 0 was measured as the sensitivity in mJ / cm ² (energy amount) unit.

(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 The same operation as in the above (1) was performed, and when a 0.25 μm rectangular resist pattern was obtained, ○ indicates that the resist pattern top was a slightly thinner or wavy resist pattern. When it became, it was evaluated as x.

(4) Stability with time of storage In the above (1), after performing the operation up to exposure, 6
After being left for 0 minutes, it was similarly heated at 110 ° C. for 90 seconds, and then developed, and the cross-sectional shape of the 0.25 μm resist pattern was observed by SEM (scanning electron microscope) photograph. 5 means that the line and space of 0.25 μm are formed in a ratio of 1: 1, and 3 means that the line width (resist pattern width) is wider than 0.25 μm and the space width is narrower than 0.25 μm. Those which were not evaluated were evaluated as 1, and the intermediates were evaluated as 4 and 2, respectively. (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.

Example 1 (1) Production of bis [2- (1-ethoxyethyloxy) cyclohexylsulfonyl] diazomethane 50 g (0.38 mol) of 2-hydroxycyclohexanethiol was dissolved in 50 g of ethanol, and 15% by weight was dissolved therein. After adding 140 g (0.37 mol) of an ethanol solution of potassium hydroxide, 33 g of methylene bromide (0.19 mol) was added.
Mol) was added dropwise at room temperature over 30 minutes. After further stirring the reaction mixture at room temperature for 1.5 hours, the precipitated potassium bromide was removed by filtration, and then 0.6 g (0.002 mol) of sodium tungstate was added.
95 g (0.98 mol) of a hydrogen peroxide solution by weight was added dropwise at 50 ° C. over 1 hour. The reaction mixture is further heated to 50 ° C.
After stirring for 20 hours with water, 300 g of water was added, and the mixture was extracted with 300 g of ethyl acetate. The solvent was distilled off to obtain 36.6 g of bis (2-hydroxycyclohexylsulfonyl) methane as a yellow oil.

Next, 25 g (0.075 mol) of this bis (2-hydroxycyclohexylsulfonyl) methane and 15 g (0.075 mol) of tosyl azide were added to ethanol 8
0 g, and 85 g (0.15 mol) of a 10% by weight aqueous solution of potassium hydroxide was added dropwise at room temperature over 30 minutes. After 125 g of water was added to the reaction mixture, the mixture was stirred at room temperature for 1 hour, and the precipitated crystals were collected by filtration to obtain 8.1 g of bis (2-hydroxycyclohexylsulfonyl) diazomethane.

Finally, 5 g (0.014 mol) of bis (2-hydroxycyclohexylsulfonyl) diazomethane and 3 g (0.042 mol) of ethyl vinyl ether are dissolved in 50 g of dioxane, and 0.1 g of pyridinium p-toluenesulfonate is dissolved. In addition, the mixture was stirred at room temperature for 20 hours. Then, after extraction with 30 g of ethyl acetate, the solvent is distilled off, and the residue is further separated by silica gel column chromatography, whereby bis [2- (1-ethoxyethyloxy) cyclohexylsulfonyl] diazomethane as a target substance is obtained.

Embedded image Was obtained in an amount of 2.0 g.

The infrared absorption spectrum of this product was measured, and as a result, a peak was observed at 2120 cm ^-1 (CN ₂ ). In addition, proton nuclear magnetic resonance spectrum ( ¹ H
-NMR) [solvent: CDCl ₃ ];
1~2.4ppm (28H, cyclohexane ring _{methylene, -CH 2 -C H 3),} 3.4~4.0ppm (8H,
Cyclohexane ring _{methylene, -C H 2 -CH 3),} 4.8
~4.9ppm (2H, -C H (CH 3) -O-) peaks were observed. FIG. 1 shows the infrared absorption spectrum and the proton nuclear magnetic resonance spectrum ( ¹ H-NMR).
And FIG.

(2) Preparation of Positive Resist Composition Polyhydroxystyrene having a weight-average molecular weight of 10,000 in which 39 mol% of hydroxyl groups are substituted by tert-butoxycarbonyloxy groups and 39 mol% of hydroxyl groups are ethoxyethoxy groups Mixture 100 with substituted polyhydroxystyrene having a weight average molecular weight of 10,000 at a weight ratio of 3: 7
Parts by weight, bis [2-
(1-Ethoxyethyloxy) cyclohexylsulfonyl] diazomethane (7 parts by weight), triethylamine (0.3 parts by weight) and salicylic acid (0.2 parts by weight) were dissolved in propylene glycol monomethyl ether acetate (490 parts by weight), and this was dissolved in a porosity of 0.2 μm. The mixture was filtered using a membrane filter to prepare a positive resist composition. As a result of evaluating various characteristics of this positive resist composition, the sensitivity was 15 mJ / cm ² , and the resolution was 0.20.
μm, the resist pattern shape was ○, the storage stability over time was 4, and the residual film ratio was 98%.

Example 2 (1) Bis [2- [1-ethoxyethyloxy] -7,
Production of 7-dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] diazomethane 30 g of potassium hydroxide (0.53 g) was added to 300 g of ethanol.
Mol) was dissolved therein, and mercaptoisoborneol 6 was added thereto.
After adding 0 g (0.32 mol), 28 g (0.16 mol) of methylene bromide was added dropwise at room temperature over 30 minutes. The reaction mixture was further stirred at 50 ° C. for 3 hours, and the precipitated potassium bromide was removed by filtration, neutralized with dilute hydrochloric acid, extracted with 500 g of methylene chloride, and the solvent was distilled off to obtain bis [2-hydroxy -7,7-Dimethylbicyclo [2.2.1] heptanylmethylthio] methane 6
7 g were obtained as a yellow oil.

Next, this bis [2-hydroxy-7,7
-Dimethylbicyclo [2.2.1] heptanylmethylthio] methane (67 g, 0.17 mol) in ethanol 300
g of sodium hydroxide, and 0.6 g of sodium tungstate was added thereto.
(2.06 mol) was added dropwise at 45 ° C. over 30 minutes. The reaction mixture was further stirred at 50 ° C. for 20 hours, water (1000 g) was added, and precipitated bis [2-hydroxy-7,7-dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] methane (51 g) was added to white crystals. As obtained.

Next, this bis [2-hydroxy-7,7
-Dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] methane (20 g, 0.045 mol) and tosyl azide (10 g, 0.051 mol) are dissolved in ethanol (80 g), and a 10% by weight aqueous potassium hydroxide solution (300 g) is added thereto.
(0.53 mol) was added dropwise at room temperature over 30 minutes. The reaction mixture was further stirred at room temperature for 2 hours, and the precipitated crystals were collected by filtration, and bis [2-hydroxy-7,7-
6.5 g of dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] diazomethane were obtained.

Finally, the bis [2-hydroxy-7,
5 g (0.011 mol) of 7-dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] diazomethane and 3 g (0.042 mol) of ethyl vinyl ether are dissolved in 50 g of dioxane, and 0.1 g of pyridinium p-toluenesulfonate is dissolved. In addition, the mixture was stirred at room temperature for 20 hours. Then, 50 g of a saturated aqueous solution of potassium carbonate was added thereto, and the precipitated crystals were collected by filtration. The obtained final product was repeatedly recrystallized from acetonitrile to obtain the desired product, bis [2- [1-ethoxyethyloxy]. ] -7,7-Dimethylbicyclo [2.2.1] heptanylmethylsulfonyl] diazomethane

Embedded image 1.7 g were obtained. The infrared absorption spectrum and proton nuclear magnetic resonance spectrum of the ⁽¹ H-NMR),
These are shown in FIGS. 3 and 4, respectively.

(2) Preparation of Positive Resist Composition In Example 1- (2), the acid generator was bis [2- [1-ethoxyethoxy] -7,7-dimethylbicyclo obtained in (1) above. [2.2.1] Heptanylmethylsulfonyl] diazomethane, except that 7 parts by weight was used.
A positive resist composition was prepared in the same manner as in (2).
As a result of evaluating various characteristics of the positive resist composition, the sensitivity was 18 mJ / cm ² , and the resolution was 0.21 μm.
m, the resist pattern shape was ○, the storage stability with time was 4, and the residual film ratio was 98%.

[0031]

The diazomethane compound of the present invention is a novel compound not described in any literature and is useful as an acid generator for a chemically amplified resist. That is, by using this as an acid generator of a chemically amplified resist, the contrast between exposed and unexposed portions is excellent, and as a result, resolution, pattern shape, and remaining film ratio are improved, and sufficient sensitivity is obtained. Is obtained.

[Brief description of the drawings]

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

FIG. 2 is a proton nuclear magnetic resonance spectrum of the diazomethane compound obtained in Example 1.

FIG. 3 is an infrared absorption spectrum of the diazomethane compound obtained in Example 2.

FIG. 4 is a proton nuclear magnetic resonance spectrum of the diazomethane compound obtained in Example 2.

 ──────────────────────────────────────────────────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 (R in the formula is a hydrogen atom or a group forming a dimethylmethylene group by two Rs in the same ring;
R ¹ and R ² are each a lower alkyl group, and n is 0 or 1). 2. A compound of the general formula (Wherein R ¹ and R ² are each a lower alkyl group;
The diazomethane compound according to claim 1, wherein n is 0 or 1. 3. A compound of the general formula (Wherein R ¹ and R ² are each a lower alkyl group;
The diazomethane compound according to claim 1, wherein n is 0 or 1.