JPH05173324A - Positive type photoresist composition - Google Patents

Abstract

PURPOSE:To obtain the photoresist composition capable of forming a pattern high in resolution and correct in mask size in a wide range of photomask line widths by incorporating a specified photosensitive material and an alkali-soluble resin. CONSTITUTION:This composition comprises the alkali-soluble resin and at least one of the photosensitive materials represented by formula in which X is -CO-, -C(R1, R2)-; when X is -CO-, each of Y1-Y7 is H, 1-4 C alkyl car alkoxy, 6-10 C aryl or aralkyl or the like, but at least one of them is not H; when Y1 is methyl, each of Y2-Y7 is same as the above expression; when X is -C(R1, R2,)-, and in the case of one of R1 and R2 being H, the other is 3-6 C alkyl, and each of Y1-Y7 is H, 1-4 C alkyl or alkoxy or acyloxy, 6-10 C aryl or aralkyl, halogen, nitro, or cyano.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-sensitive positive photoresist composition, and more particularly to a photoresist composition for microfabrication having a high resolution and sensitivity and a good pattern cross-sectional shape. It is a thing. The positive type photoresist according to the present invention is a semiconductor wafer,
It is applied to a substrate of glass, ceramics, metal or the like by spin coating or roller coating to a thickness of 0.5 to 3 μm. After that, it is heated and dried, and a circuit pattern or the like is baked by irradiation of ultraviolet rays or the like through an exposure mask and developed to form a positive image. Further, by etching this positive image as a mask, a pattern can be processed on the substrate. IC is a typical application field
Etc., semiconductor manufacturing process, liquid crystal, circuit board manufacturing such as thermal head, and other photo-ablation process.

[0002]

2. Description of the Related Art As a positive photoresist composition,
Generally, a composition containing an alkali-soluble resin and a naphthoquinonediazide compound as a photosensitive material is used. For example, US Pat. No. 3,666,473 as “Novolak type phenol resin / naphthoquinone diazide substituted compound”
No., USP-4,115,128 and USP-4,17
No. 3,470, etc., and the most typical composition is "cresol-formaldehyde novolak resin /
An example of "trihydroxybenzophenone-1,2 naphthoquinone diazide sulfonate" is Thompson "Introduction Tou Microlithography".
(LF Thompson "Intro-ducti
on to Microlitho-graphics ")
(ACS publication, No. 219, P112 to 121). Novolac resin as a binder is particularly useful for this application because it can be dissolved in an alkaline aqueous solution without swelling, and when it is used as a mask for etching, it gives a high resistance to plasma etching. Is. Further, the naphthoquinonediazide compound used for the photosensitive material acts as a dissolution inhibitor which lowers the alkali solubility of the novolak resin by itself, but when decomposed by light irradiation, an alkali-soluble substance is generated and rather the alkali solubility of the novolak resin is increased. It is unique in that it acts to enhance it, and is particularly useful as a photosensitive material for a positive photoresist because of its large change in properties with respect to light. From this point of view, many positive photoresists containing a novolak resin and a naphthoquinonediazide type photosensitive material have been developed and put to practical use from the viewpoint of 1.5 μm to 2 μm.
We have achieved sufficient results in line width processing down to about μm.

However, the degree of integration of integrated circuits is increasing more and more, and in the manufacture of semiconductor substrates such as VLSIs,
It has become necessary to process an ultrafine pattern having a line width of μm or less. For such applications, a photoresist having a particularly high resolution, a high pattern shape reproducibility that accurately copies the shape of the exposure mask, and a high sensitivity from the viewpoint of high productivity is required, and the conventional positive photoresist described above is applicable. The reality is that we cannot do it.

[0004]

Therefore, the object of the present invention is to (1) particularly in the manufacture of semiconductor devices.
A positive photoresist composition having high resolution,
(2) A positive photoresist composition that accurately reproduces mask dimensions over a wide range of photomask line width,
(3) A positive photoresist composition capable of forming a resist pattern having a cross-sectional shape with a high aspect ratio in a pattern having a line width of 1 μm or less, (4) a pattern having a shape in which the side wall of the pattern cross section is nearly vertical An object of the present invention is to provide a positive photoresist composition to be obtained, (5) a positive photoresist composition having a wide development latitude, and (6) a positive photoresist composition in which a resist image obtained has excellent heat resistance.

[0005]

Means for Solving the Problems As a result of intensive studies made by the present inventors while paying attention to the above various characteristics, the object of the present invention is to provide at least one photosensitive material represented by the following general formula (I) and an alkali-soluble resin. It has been found that a positive type photoresist composition is characterized by containing

[0006]

[Chemical 3]

[0007] where

[0008]

[Chemical 4]

The present invention will be described in detail below. R is H
Or

[0010]

[Chemical 5]

Represents one or more substituents selected from, and at least one is not H.

The linking group X is --C (═O)-or --C.
Represents (R ₁ , R ₂ )-. When X is -C (= O)-, Y
_{1 to} Y ₇ represent H, C _{1 to} C ₄ alkyl group, alkoxy group or acyloxy group, C _{6 to} C ₁₀ aryl group or aralkyl group, halogen, nitro group or cyano group. However, at least one is not H. Further, when Y ₁ is CH ₃ , at least one of Y _{2 to} Y ₇ is not H. A more preferred embodiment among these is the case where at least one is a C ₁ -C ₄ alkyl group or alkoxy group. When X is —C (R ₁ , R ₂ ) —, when one of R ₁ and R ₂ is H, the other is a C ₃ , C ₄ or C ₆ alkyl group, and R ₁ and R ₂ When one is CH ₃ , the other is a C _{2 to} C ₆ alkyl group, and when R ₁ and R ₂ are not both H and CH ₃ , R ₁ and R ₂ may be the same or different, and C ₂ to C ₆
Is an alkyl group. Further, Y _{1 to} Y ₇ represent the above-mentioned groups, and are preferably H, C _{1 to} C ₄ alkyl groups, alkoxy groups, nitro groups or cyano groups.

The photosensitive material represented by the general formula (I) comprises a polyhydroxy compound represented by the following general formula (I ')
2-naphthoquinonediazide-5 (and / or -4)-
Obtained by reacting with a sulfonyl chloride.
Here, X, Y _{1 to} Y ₇ are as described above.

[0014]

[Chemical 6]

A polyhydroxy compound represented by the general formula (I ') and 1,2-naphthoquinonediazide-5 (and / or
Or, a usual method is used for the esterification reaction with -4) -sulfonyl chloride. That is, a predetermined amount of the polyhydroxy compound represented by (I ′), 1,2-naphthoquinonediazide-5 (and / or -4) -sulfonyl chloride and dioxane, acetone, γ-butyrolactone,
A solvent such as methyl ethyl ketone or N-methylpyrrolidone is charged into the flask, and a basic catalyst such as sodium hydroxide, sodium carbonate, sodium hydrogen carbonate or triethylamine is added dropwise for condensation. The product obtained is
After washing with water, purification and drying. In this way, the general formula (I)
A photosensitive material represented by can be prepared.

In the above esterification reaction, a mixture having different esterification numbers and esterification positions can be obtained. Therefore, the esterification rate in the present invention is defined as the average value of this mixture. The esterification rate thus defined can be controlled by the mixing ratio of the raw material compound (I ′) and 1,2-naphthoquinonediazide-5 (and / or -4) -sulfonyl chloride. That is, the added 1,2-naphthoquinonediazide-5 (and / or-
Since 4) -sulfonyl chloride causes an esterification reaction substantially in its entirety, the molar ratio of the raw materials may be adjusted to obtain a mixture having a desired esterification rate. If necessary, 1,2-naphthoquinonediazide-5-sulfonic acid ester and 1,2-naphthoquinonediazide-4-sulfonic acid ester can be used in combination. The reaction temperature in the above method is usually -20 to 60 ° C, preferably 0.
-40 ° C.

The alkali-soluble novolac resin used in the present invention contains 0.6 mol of aldehydes per mol of phenols.
It is obtained by addition-condensing ˜1.0 mol under an acidic catalyst. As the phenols, phenol, o-cresol, m-cresol, p-cresol and the like can be used alone or in combination of two or more kinds. Formaldehyde, paraformaldehyde, acetaldehyde, halogenated acetaldehyde (eg, chloro-, bromo-), or furfural can be used as the aldehyde, and hydrochloric acid, sulfuric acid, formic acid, oxalic acid, acetic acid, or the like can be used as the acidic catalyst. Molecular weight 10 thus obtained
Novolak resin of 0-50000 shows alkali solubility. The ratio of the photosensitive material to the alkali-soluble novolak resin used in the present invention is 5 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the novolak resin. If the use ratio is less than 5 parts by weight, the residual film rate is remarkably lowered, and if it exceeds 100 parts by weight, the sensitivity and the solubility in a solvent are lowered.

In the present invention, the above-mentioned photosensitive material should be mainly used, but if necessary, an ordinary photosensitive material such as 2,
3,4-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, etc. and 1,2-naphthoquinonediazide-5- (and / or- 4-) An esterified product with sulfonyl chloride can be used in combination. In this case, 100 parts by weight or less based on 100 parts by weight of the photosensitive material (I),
It can be preferably used in a proportion of 30 parts by weight or less.

The composition of the present invention may further contain other polyhydroxy compounds in order to accelerate the dissolution in the developing solution. Preferred polyhydroxy compounds include:
Phenols, resorcin, phloroglucin, 2,3,4
-Trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,3,4,3 ', 4',
5'-hexahydroxy benzophenone, acetone-pyrogallol condensation resin, etc. can be mentioned.

As the solvent for dissolving the photosensitive material of the present invention and the alkali-soluble novolak resin, ketones such as methyl ethyl ketone and cyclohexanone, 4-etoki-2
-Ketoethers such as butanone, 4-methoxy-4-methyl-2-pentanone, alcohol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, ethers such as dioxane and ethylene glycol dimethyl ether, methyl cellosolve acetate, ethyl Cellosolve esters such as cellosolve acetate, fatty acid esters such as butyl acetate, methyl lactate, ethyl lactate, halogenated hydrocarbons such as 1,1,2-trichloroethylene, dimethylacetamide, N-
Examples thereof include highly polar solvents such as methylpyrrolidone, dimethylformamide and dimethylsulfoxide. These solvents may be used alone or as a mixture of a plurality of solvents.

If necessary, the positive photoresist composition of the present invention may contain a dye, a plasticizer, an adhesion aid, a surfactant and the like. Specific examples thereof include dyes such as methyl violet, crystal violet and malachite green, stearic acid, acetal resins, phenoxy resins, plasticizers such as alkyd resins, adhesion promoters such as hexamethyldisilazane and chloromethylsilane, and nonyl. There are surfactants such as phenoxypoly (ethyleneoxy) ethanol and octylphenoxypoly (ethyleneoxy) ethanol.

After applying the above-mentioned positive photoresist composition onto a substrate (eg, silicon / silicon dioxide coating) used in the production of precision integrated circuit devices by a suitable coating method such as a spinner or coater, the predetermined composition is applied. A good resist can be obtained by exposing through a mask and developing. As a developer for the positive photoresist composition of the present invention, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, inorganic alkalis such as aqueous ammonia, ethylamine,
Primary amines such as n-propylamine, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetra Aqueous solutions of quaternary ammonium salts such as methylammonium hydroxide and tetraethylammonium hydroxide, and cyclic amines such as pyrrole and piperidine, and alkalis can be used. Further, an appropriate amount of alcohols and surfactants may be added to the above aqueous solution of alkalis for use. Examples of the present invention will be shown below, but the present invention is not limited thereto. Unless otherwise specified,% is
Indicates weight percent.

[0023]

【Example】

 (1) Synthesis of Photosensitive Material a 10 g of the following compound (a ′),

[0024]

[Chemical 7]

22.0 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 480 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 8.5 g / 35 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2100 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material a having the physical properties shown in Table 1.

(2) Synthesis of Photosensitive Material b 10 g of the following compound (b '),

[0027]

[Chemical 8]

25.8 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 560 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 10.0 g / 40 ml was gradually added dropwise and reacted at 25 ° C. for 3 hours. 1% of reaction mixture
It was poured into 2500 ml of an aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material b having the physical properties shown in Table 1.

(3) Synthesis of Photosensitive Material c 10 g of the following compound (c '),

[0030]

[Chemical 9]

25.3 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 550 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Next, triethylamine / acetone = 9.8 g / 40 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2500 ml of a 1% hydrochloric acid aqueous solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material c having the physical properties shown in Table 1.

(4) Synthesis of Photosensitive Material d 10 g of the following compound (d '),

[0033]

[Chemical 10]

28.6 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 620 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 11.1 g / 45 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. 1% of reaction mixture
It was poured into 2800 ml of an aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material d having the physical properties shown in Table 1.

(5) Synthesis of Photosensitive Material e 10 g of the following compound (e '),

[0036]

[Chemical 11]

20.8 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 450 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 8.1 g / 35 ml was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2000 ml of a 1% hydrochloric acid aqueous solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material e having the physical properties shown in Table 1.

(6) Synthesis of Photosensitive Material f 10 g of the following compound (f '),

[0039]

[Chemical 12]

17.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 380 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 6.8 g / 30 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 1700 ml of a 1% hydrochloric acid aqueous solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material f having the physical properties shown in Table 1.

(7) Synthesis of Photosensitive Material 10 g of the following compound (g '),

[0042]

[Chemical 13]

20.8 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 450 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 8.1 g / 35 ml was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2000 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material g having the physical properties shown in Table 1.

(8) Synthesis of Photosensitive Material h 10 g of the following compound (h '),

[0045]

[Chemical 14]

15.6 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 340 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 6.2 g / 30 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 1500 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material h having the physical properties shown in Table 1.

(9) Synthesis of Photosensitive Material i 10 g of the following compound (i '),

[0048]

[Chemical 15]

17.8 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 390 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 6.9 g / 35 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 1700 ml of a 1% hydrochloric acid aqueous solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material i having the physical properties shown in Table 1.

(10) Synthesis of Photosensitive Material j 10 g of the following compound (j '),

[0051]

[Chemical 16]

14.8 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 320 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 5.7 g / 30 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 1400 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material j having the physical properties shown in Table 1.

(11) Synthesis of Photosensitive Material k: 10 g of the following compound (k '),

[0054]

[Chemical 17]

1,2-naphthoquinonediazide-5-sulfonyl chloride (15.8 g) and acetone (340 ml) were added to 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 6.1 g / 35 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 1500 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material k having the physical properties shown in Table 1.

(12) Synthesis of Photosensitive Material l 10 g of the following compound (l '),

[0057]

[Chemical 18]

21.9 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 470 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 8.5 g / 40 ml was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2100 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material 1 having the physical properties shown in Table 1.

(13) Synthesis of Photosensitive Material m 10 g of the following compound (m '),

[0060]

[Chemical 19]

18.8 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 400 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 7.4 g / 30 ml was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 1800 ml of a 1% hydrochloric acid aqueous solution, the resulting precipitate was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material m having the physical properties shown in Table 1.

(14) Synthesis of Photosensitive Material n 10 g of the following compound (n '),

[0063]

[Chemical 20]

15.2 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 330 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 5.9 g / 25 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 1500 ml of a 1% hydrochloric acid aqueous solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material n having the physical properties shown in Table 1.

(15) Synthesis of Photosensitive Material o 10 g of the following compound (o '),

[0066]

[Chemical 21]

20.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 450 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 8.0 g / 35 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2000 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material o having the physical properties shown in Table 1.

(16) Synthesis of Photosensitive Material p 10 g of the following compound (p '),

[0069]

[Chemical formula 22]

20.8 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 450 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 8.1 g / 35 ml was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2000 ml of a 1% hydrochloric acid aqueous solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material p having the physical properties shown in Table 1.

(17) Synthesis of Photosensitive Material q 10 g of the following compound (q '),

[0072]

[Chemical formula 23]

1,2-naphthoquinonediazide-5-sulfonyl chloride (17.8 g) and acetone (400 g) were charged into a three-necked flask and uniformly dissolved. Then, triethylamine / acetone = 7.0 g / 30 ml was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 1700 ml of a 1% hydrochloric acid aqueous solution, the precipitate formed was filtered off,
After washing with water and drying (40 ° C.), a photosensitive material q having the physical properties shown in Table 1 was obtained.

(18) Synthesis of Photosensitive Material r (Comparative Example 1) 10 g of the following compound (r '),

[0075]

[Chemical formula 24]

27.5 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 600 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 10.7 g / 45 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. 1% of reaction mixture
It was poured into 2600 ml of an aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material r having the physical properties shown in Table 1.

(19) Synthesis of Photosensitive Material s (Comparative Example 2) 10 g of the following compound (s'),

[0078]

[Chemical 25]

24.2 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 540 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 9.4 g / 40 ml was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2300 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material s having the physical properties shown in Table 1.

(20) Synthesis of Photosensitive Material t (Comparative Example 3) 10 g of the following compound (t '),

[0081]

[Chemical formula 26]

20.8 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 450 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 8.1 g / 33 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2000 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material t having the physical properties shown in Table 1.

(21) Synthesis of Photosensitive Material u (Comparative Example 4) 10 g of the following compound (u '),

[0084]

[Chemical 27]

12.8 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 210 ml of acetone were mixed with 3 parts.
It was charged in a single-necked flask and uniformly dissolved. Then, triethylamine / acetone = 7.3 g / 30 ml was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 1800 ml of a 1% hydrochloric acid aqueous solution, the resulting precipitate was filtered off, washed with water and dried (40 ° C.) to obtain a photosensitive material u having the physical properties shown in Table 1.

[0086]

[Table 1]

(22) Synthesis of novolak resin m-cresol 37 g, p-cresol 63 g, 37%
A formalin aqueous solution (51.0 g) and oxalic acid (0.05 g) were charged into a three-necked flask, and the temperature was raised to 100 ° C. with stirring and reacted for 7 hours. After reaction, cool to room temperature, 30m
The pressure was reduced to mHg. Then, the temperature was gradually raised to 150 ° C. to remove water and unreacted monomers. The obtained novolak resin had a weight average molecular weight of 7,500 (in terms of polystyrene).

(23) Preparation and Evaluation of Positive Photoresist Composition 1.1 of Photosensitive Materials a to u Obtained in (1) to (21)
0 g and 5 g of the cresol novolak resin (molecular weight 7500) obtained in the above (22) were dissolved in 18 g of ethyl cellosolve acetate and filtered using a 0.2 μm microfilter to obtain a photoresist (Comparative Examples 1 to 15, Comparative Examples 1 to 15). Examples 1, 2) were prepared. This photoresist composition was applied to a silicon wafer using a spinner and dried in a convection oven in a nitrogen atmosphere at 110 ° C. for 30 minutes to obtain a resist film having a thickness of 1.2 μm. This film was exposed using a reduction projection exposure device (NSR1505 manufactured by Nikon Corporation), developed with a 2.38% tetramethylammonium hydroxide aqueous solution for 1 minute, washed with water for 30 seconds and dried.
The resist pattern of the silicon wafer thus obtained was observed with a scanning electron microscope to evaluate the resist. The results are shown in Table 2. The sensitivity was defined as the reciprocal of the exposure amount that reproduces a mask pattern of 1.0 μm, and shown as a relative value to the sensitivity of Comparative Example 1. The residual film rate was expressed as a percentage of the ratio of the unexposed area before and after development. The resolution is 1.
It represents the limiting resolution at an exposure dose that reproduces a mask pattern of 0 μm. The heat resistance showed the temperature at which the resist pattern-patterned silicon wafer was baked in a convection oven for 30 minutes and the pattern was not deformed. The shape of the resist is represented by the angle (θ) formed by the resist wall surface and the plane of the silicon wafer in the 1.0 μm resist pattern section. As can be seen, the photosensitive material a of the present invention a
The resists using ~ q were particularly excellent in resolution and resist shape. The photosensitizer of the present invention is also excellent in solubility in ethylene glycol monoethyl ether acetate, and the resist composition solution using these photosensitizers did not cause precipitation even when left at 40 ° C. for 30 days. However, when the resist composition solutions using the photoconductors r to u of Comparative Examples were left under the same conditions, precipitation was observed in the resist composition.

[0089]

[Table 2]

[0090]

The positive photoresist composition of the present invention is excellent in resolution, faithful reproducibility, cross-sectional shape of resist image, development latitude, heat resistance and storage stability of composition solution, and is suitable as a photoresist for fine processing. Used for.

Claims (1)

[Claims] 1. A positive photoresist composition comprising at least one photosensitive material represented by the following general formula (I) and an alkali-soluble resin. [Chemical 1] Where: X: -C (= O) - or _{-C (R 1, R 2)} - represents a. However, when X is —C (═O) —, Y _{1 to} Y ₇ are H, C _{1 to} C ₄ alkyl group, alkoxy group or acyloxy group, C ₆
To C ₁₀ aryl group or aralkyl group, halogen,
Represents a nitro group or a cyano group. However, at least 1
One is not H. Further, when Y ₁ is CH ₃ , at least one of Y _{2 to} Y ₇ is not H. X is -C (R ₁ , R ₂ )-
When one of R ₁ and R ₂ is H, the other is a C ₃ , C ₄ or C ₆ alkyl group, and when _one of R ₁ and R ₂ is CH ₃ , the other is C ₂ ~ When it is a C ₆ alkyl group and R ₁ and R ₂ are not both H and CH ₃ , R ₁ and R ₂ may be the same or different and are a C _{2 to} C ₆ alkyl group. Also, Y ₁ ~
Y ₇ represents H, a C _{1 to} C ₄ alkyl group, an alkoxy group or an acyloxy group, a C _{6 to} C ₁₀ aryl group or an aralkyl group, a halogen, a nitro group or a cyano group.