JPH01291240A - Positive type photoresist material containing novel photosensitive agent - Google Patents

Abstract

PURPOSE:To improve the resolution and the process stability of the title material, without injuring the sensitivity and the heat resistance of the photoresist material by incorporating a 1,2-quinone diazide compd. composed of a specified compd. in the photoresist material. CONSTITUTION:The 1,2-quinone diazide compd. shown by formula I and an alkali soluble resin are incorporated in the photoresist material. In the formula, R is 1-4 C alkylene group, Ra and Rb are the same or the different with each other, and are each H, OH, 1-4 C alkyl group or halogen atom, D is 1,2-naphthoquinone diazide-4-sulfonyl group, 1,2-naphthoquinone diazide-5-sulfonyl group or 1,2-benzoquinone diazide-4-sulfonyl group, (m) and (n) are each an integer of 0-5, (m+n)>=1. Thus, the excellent performances of the photoresist material such as the sensitivity, the resolution, the heat resistance and a pattern shape of the photoresist, are obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an alkali-soluble resin that can be used as a resist material sensitive to radiation such as ultraviolet rays, deep ultraviolet rays, electron beams, and X-rays, and a novel 1,2- The present invention relates to a positive photoresist material comprising a quinonediazide compound and a pattern forming method.

[Prior Art] In recent years, the density and integration of semiconductor integrated circuits have progressed, and we have entered an era where the degree of integration is 4 Mbits or more, and pattern formation of submicron rules or even smaller ones has become necessary.

The positive photoresist consists of an alkali-soluble novolac resin and a 1.degree. 2-quinonediazide compound which functions as an alkali dissolution inhibitor.

In the radiation irradiated part, the 1,2-quinonediazide compound becomes ketene via carbene, reacts with moisture inside and outside the system to produce indene carboxylic acid, and becomes easily dissolved in the alkaline aqueous solution. On the other hand, the unirradiated area is dissolved in an alkaline developer, hardly swells, and maintains a high residual film ratio. As a result, a high resolution resist pattern is obtained. Conventional cyclized polyisoprene-based negative resists have limited resolution due to swelling of the film during development, and recently positive resists have been mainly used.

By the way, in order to meet increasingly stringent requirements, various improvements are being attempted in positive photoresists, and a wide range of detailed studies are being conducted on everything from resins, photosensitizers, developers, and additives. .

In particular, high sensitivity, high resolution, rectangularity of pattern profile, high dry etching resistance, high heat resistance, and process stability are strongly desired and are the goals of improvement.

[Problem to be solved by the invention] However, sensitivity and resolution, sensitivity and heat resistance, and sensitivity,
Resolution, heat resistance and process stability tend to contradict each other. For example, increasing the molecular weight of the resin increases heat resistance, but reduces sensitivity, resolution, and process stability. When copolymerization is performed to improve heat resistance, process stability decreases. Furthermore, when the amount of photosensitizer is increased, the resolution improves, but the sensitivity decreases. As described above, since there are many contradictory properties, it has been extremely difficult to achieve high performance without degrading other properties.

Furthermore, in the case of ultraviolet light as an exposure source, for example, its wavelength is shifting from g-line to i-line. Various resists that can be used with g-line or i-line are being developed, but a resist that can be used with both has not yet been developed.

[Means for Solving the Problems] As a result of extensive research based on this background, the present inventors discovered that a compound containing a piperazine ring is effective. In other words, by using the 1,2-quinonediazide compound consisting of the novel compound (1) of the present invention, resolution and process stability can be improved without impairing sensitivity and heat resistance, and it can be used for g-line and i-line. The present inventors have discovered that this photoresist can be used as a photoresist, and have completed the present invention.

That is, general formula (I), (wherein R represents an alkylene group having 1 to 4 carbon atoms, R,
, R, represent the same or different H, OH, an alkyl group having 1 to 4 carbon atoms, or a halogen atom. D represents a 1,2-naphthoquinonediazide-4-sulfonyl group, a 1,2-naphthoquinonediazide-5-sulfonyl group, or a 1,2-benzoquinonediazide-4-sulfonyl group. m and n each represent an integer of 0 to 5, and m+n is 1 or more. ) A positive photoresist material comprising a novel 1,2-quinonediazide compound represented by the following formula and an alkali-soluble resin, and a pattern forming method are provided.

In addition, as an alkylene group of R in general formula (I), a methylene group, an ethylene group, a propylene group, a butylene group, etc. can be mentioned. Further, examples of the alkyl group of R1 and R1 include methyl group, ethyl group, propyl group, butyl group, etc., and examples of the halogen include chlorine, fluorine, bromine, etc.

The novel 1°2-quinonediazide compound represented by the general formula (I) in the present invention has the following general formula (n), (where R
represents an alkylene group having 1 to 4 carbon atoms, and R,, R, represents the same or different H1 alkyl group having 1 to 4 carbon atoms, or a halogen atom. mSn each represents an integer from 0 to 5,
m+n is 1 or more. ) 1,2-naph)・quinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonyl chloride, 1,2-benzoquinonediazide-4-
It can be synthesized by esterifying all or part of it with sulfonyl chloride.

There are no particular limitations on the method of synthesizing general formula (II); for example, it can be synthesized by the following method. It can be synthesized by reacting polyhydroxybenzoyl chloride and aminoalkylpiperazine or by reacting polyhydroxybenzoic acid and aminoalkylpiperazine in acetic anhydride under reflux.

Thereafter, it can be purified by recrystallization or column separation.

Esterification of general formula (I[) with sulfonyl chloride can be carried out by reacting the necessary equivalence of sulfonyl chloride in the presence of a base such as potassium hydroxide, sodium hydroxide, alkali carbonate, triethylamine, or pyridine. Can be synthesized.

The alkali-soluble resin of the present invention includes 1 and 2 of the present invention.
- There is no particular limitation as long as the resin dissolves uniformly in the quinonediazide compound, but examples include the following. Examples include novolac resins such as phenol and cresol, polyvinylphenol or copolymers thereof, and polymers containing carboxylic acids such as styrene-maleic anhydride copolymers or half esters thereof. Particularly preferred is a novolac resin, which can be synthesized by the following method. The corresponding monomer and aldehydes such as formaldehyde, paraformaldehyde, and acetaldehyde are combined with formic acid, oxalic acid,
It can be synthesized by polycondensation according to a known method in the presence of an acidic catalyst such as acetic acid, hydrochloric acid, nitric acid, sulfuric acid, or Lewis acid. The weight average molecular weight of the resin is 2000 to 30'00
0 (polystyrene equivalent) is preferable. Within this range, sensitivity, resolution, heat resistance, and process stability are excellent.

Further, as monomers used in the novolac resin that can be used in the present invention, for example, the following phenols can be used alone or in a mixture of two or more. Phenols include phenol, 0-cresol, m-cresol, p-cresol, 0-ethylphenol, m-ethylphenol, p-ethylphenol,
o-n-butylphenol, m-n-butylphenol, p-n-butylphenol, o-t-butylphenol, m-t-butylphenol, p-t-butylphenol, 0-methoxyphenol, m-methoxyphenol, p-methoxyphenol , 0-fluorophenol, m-fluorophenol, p-fluorophenol,
0-chlorophenol, m-chlorophenol, p-chlorophenol, 0-nitrophenol, m-nitrophenol, p-nitrophenol, 2,4-xylenol, 2.5-xylenol, 3,4-xylenol, 3
, 5-xylenol and the like. Furthermore, if necessary, the hydroxyl group of the phenol may be substituted with a sulfonic acid or a carboxylic acid ester. Examples of the esterification component include alkyl groups such as methyl, ethyl, and propyl, and aromatic rings such as phenyl, tolyl, benzoic acid, naphthyl, benzyl, cumyl, and phenethyl.

The amount of the novel 1,2-quinonediazide compound of the present invention is preferably 20 to 50 parts by weight based on 100 parts by weight of the alkali-soluble resin. Within this range, a sufficient difference in solubility in the developer between exposed and unexposed areas can be obtained, and a pattern with excellent sensitivity and resolution can be obtained.

The positive photoresist material of the present invention contains an alkali-soluble resin and a 1,2-quinonediazide compound at a solid content of 20%.
It is obtained by dissolving it in an appropriate solvent so that the amount becomes 40 parts by weight. Examples of the solvent include ethylene glycol monoalkyl ether and its acetates, propylene glycol monoalkyl ether and its acetates, diethylene glycol dialkyl ethers, ketones such as methyl ethyl ketone and cyclohexanone, acetic acid esters such as ethyl acetate and butyl acetate, +-Aromatic hydrocarbons such as toluene and xylene, dimethylacetamide, dimethylformamide, and the like.

These solvents can be used alone or in combination of two or more. Moreover, other photosensitizers other than those of the present invention can also be used in combination. Furthermore, if necessary, nonionic, fluorine-based, silicone-based surfactants can be added to improve coating properties, and other sensitizers, colorants, stabilizers, etc. Certain additives may also be included.

[Function] The positive photoresist composition comprising the alkali-soluble resin and the new 1,2-quinonediazide compound of the present invention can be used for resist pattern formation using ultraviolet rays, deep ultraviolet rays, electron beams, X-rays, etc. Excellent sensitivity, resolution, heat resistance, and process stability.

There are no particular limitations on how to use the positive photoresist material of the present invention to form a resist pattern using radiation, and the method can be carried out in accordance with a conventional method.

For example, the positive photoresist solution of the present invention is prepared by dissolving an alkali-soluble resin, a 1,2-quinonediazide compound, and additives in a solvent, and filtering the solution through a 0.2 μm filter. A resist film is obtained by spin-coding a resist solution onto a substrate such as a silicon wafer and pre-baking it. Thereafter, a resist pattern can be formed by performing exposure using a reduction projection exposure device, an electron beam exposure device, or the like, and developing.

As a developer, for example, an organic alkali aqueous solution such as a quaternary ammonium salt such as tetramethylammonium hydroxide, choline, amines, or an inorganic alkali aqueous solution such as sodium hydroxide, potassium hydroxide, sodium carbonate, or aqueous ammonia is used. Can be used. Other methods such as coating, pre-baking, exposure, and development can be carried out by conventional methods.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Synthesis Example 1 In a 300 ml 3 flask, 9.2 g of 3.4-dihydroxybenzoyl chloride and 3.0 g of aminoethylpiperazine were added.
8 g of triethylamine was dissolved in 250 ml of chloroform, and a solution of 501 d of chloroform containing 5.9 g of triethylamine was added dropwise at room temperature with stirring over 30 minutes. After that, 200
The reaction continued for hours. After the reaction, the reaction solution was sequentially washed with saturated brine, IN aqueous hydrochloric acid, saturated food, and brine, and dried over anhydrous sodium sulfate. After that, filtration, the solvent was removed using an evaporator, and N,N--bis(3゜4
-dihydroxybenzoyl)aminoethylpiperazine was obtained. Purification of the compound was performed by column separation. Yield was 3.4g. Purity determined by reverse phase chromatography was 95.6%.

Elemental analysis values are C59.4%, N5.5%, N10.9
%showed that.

Synthesis Example 2 In a 300 mal 3-tube flask, N,N--bis(
2.8 g of 3,4-dihydroxybenzoyl)aminoethylpiperazine and 1,2-naphthoquinonediazide-5-
5.7 g of sulfonyl chloride was dissolved in 50 g of dioxane, and while stirring at room temperature, triethylamine 2.
10 ml of a 4 g dioxane solution was added dropwise over 20 minutes.

Thereafter, the reaction was continued for 3 hours. After the reaction, triethylamine hydrochloride was filtered off, and the filtrate was poured into a large amount of ion-exchanged water to precipitate a 1,2-quinonediazide compound. This was filtered, washed successively with ion-exchanged water and ethanol, and then dried to obtain a powder. Yield was 5.9g.

Elemental analysis values are C54.4%, N3.0%, N11.8
%, N8.6%.

Synthesis Example 3 According to Synthesis Examples 1 and 2, N,N=-bis(3°5-dihydroxybenzoyl)aminoethylpiperazine 1,
2-naphthoquinonediazide-5-sulfonic acid ester (
An average of 3 hydroxyl groups were esterified).

Synthesis Example 4 30g of O-cresol in a 300ml 4 flask,
m-cresol 55g, p-cresol 45g, oxalic acid 2
1.75 g of hydrate was added. Under a nitrogen atmosphere, the mixture was immersed in an oil bath without stirring, and the temperature was raised to an internal temperature of 100°C. While maintaining the internal temperature at 1000C, 86 g of a 35% formalin aqueous solution was added dropwise over 90 minutes. Thereafter, the reaction was continued for 10 minutes to synthesize a novolac resin. After the reaction, 112 g of resin powder was obtained by repeating dissolution and precipitation and drying.

The weight average molecular weight of novolak resin is GPCI111j
As a result, it was 4950 in terms of polystyrene. In addition, the degree of dispersion (weight average molecular weight/number average molecular weight) is 4.7
It was 3.

Example] 1,2-quinonediazide compound obtained in Synthesis Example 2 2.25
g and 8 g of the novolak resin obtained in Synthesis Example 4.

and ethylene glycol monoethyl ether acetate-1
-Dissolved in 24g and filtered with 0.2μm membrane-
The solution was filtered to obtain Lens I solution.

The resist solution was spin-coated onto a 4-inch silicon wafer using a spinner, and prebater was performed in a circulating constant temperature bath at 90° C. for 30 minutes to obtain a resist film with a thickness of 1.5 μm. Next, a reduction projection exposure device (manufactured by GCA, DSW-630
0A,N,A,=0.35) through the reticle.

Immersion development was performed at 25° C. for 1 minute using a 2.25% by weight aqueous solution of tetramethylammonium hydroxide as a developer.

The exposure dose for resolving 1.0 μm line/space on a one-to-one basis was 152 mJ/cm 2 .

Regarding the resolution, a 0.7 μm line/space could be resolved, and the pattern was rectangular.

Next, resist patterns with 2 μm lines/spaces of 140, 145, 150, 155°160.16
Baking was performed in a circulating constant temperature bath at each temperature of 5,170° C. for 30 minutes, and heat resistance was evaluated based on the presence or absence of pattern deformation. As a result, the heat resistance was 155°C.

Example 2 DSW-6300A is used as a reduction projection exposure apparatus.
An exposure test was carried out in accordance with Example 1, except that a linear reduction projection exposure apparatus having a lens of -0.42 was used.

As a result, the exposure amount for resolving 1.0 μm line/space one to one was 175 mJ/cm 2 .

Regarding the resolution, a 0.5 μm line/space could be resolved, and the pattern was rectangular.

Example 3 Using the 1,2-quinonediazide compound obtained in Synthesis Example 3, an exposure test and a heat resistance test were conducted according to Example 1.

As a result, the exposure dose for resolving 1.0 μm line/space one-to-one was 165 mJ/cm2.

Regarding resolution, it was possible to resolve 0.7 μm line/space, and the pattern was rectangular.

Heat resistance was 155°C.

[Effects of the Invention] The positive photoresist compound comprising the alkali-soluble resin of the present invention and the novel 1,2-quinonediazide compound has 1
, 2-quinonediazide compound contains a piperazine ring,
It is made of carboxylic acid amide bonds, has excellent sensitivity, resolution, heat resistance, and pattern shape, and exhibits good performance with both G-line and I-line light sources, so it is suitable for manufacturing semiconductor integrated circuit devices such as VLSIs. suitable.

Claims (2)

[Claims] (1) General formula (I), ▲Mathematical formula, chemical formula, table, etc.▼(I) (However, R represents an alkylene group having 1 to 4 carbon atoms, and R_
a and R_b are the same or different H, OH, carbon number 1-
4 represents an alkyl group or a halogen atom: D is 1, 2
-naphthoquinonediazide-4-sulfonyl group, 1,2-
naphthoquinonediazide-5-sulfonyl group or 1,2-
Represents a benzoquinonediazide-4-sulfonyl group: m and n each represent an integer of 0 to 5, and m+n is 1 or more. A positive photoresist material comprising a novel 1,2-quinonediazide compound represented by ) and an alkali-soluble resin. (2) A pattern forming method using the positive photoresist material according to claim 1.