JPH02248951A - Photoresist composition - Google Patents

Abstract

PURPOSE:To form a resist pattern high in resolution with high sensitivity and antihalation effect without deteriorating resist performance according to prebaking conditions by incorporating a specified compound. CONSTITUTION:The photoresist composition contains at least one of the compounds represented by formula I in which each of R<1> and R<2> is 1 - 16 C alkyl, phenyl, aralkyl, cyclohexyl, alkoxyalkyl, tetrahydrofurfuryl, or H; R<3> is 1 - 8 C alkyl, acetyl, or H; R<4> is 1 - 4 C alkyl, halogen, alkoxy, or H; and R<5> is 1 - 4 C alkyl or H, thus permitting the obtained photoresist to be superior in line width controlability even on a highly reflective substrate, sensitivity, resolution, and sublimation resistance, and a fine pattern good in reproducibility to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to photoresist compositions, and more particularly, to photoresist compositions that are suitable for use in photoresist compositions. The present invention relates to a novel photoresist composition that can maintain excellent pattern forming ability.

[Conventional technology]

Electronic components such as semiconductors, ICs, and LSIs are manufactured by a method in which an arbitrary circuit pattern is drawn by optical means, exposed to light on a resist through a mask, developed, and then the substrate is etched.

BACKGROUND ART In recent years, as integrated circuits have become more highly integrated, patterns have become increasingly finer, and it is desired that resists be able to form fine patterns with high precision. However, in the above method, the resolution of the resist image is significantly affected by the diffraction of the exposing light and the scattering and reflection of the light from the surface of the underlying silicone substrate. Especially when using a substrate with aluminum vapor-deposited on the surface of a silicone wafer,
Since the reflectance of the aluminum surface is high and the halation light is therefore large, there is a problem in that diffuse reflection occurs on flat parts of the surface, making it difficult to accurately reproduce a pattern with a narrow line width of several nanometers.

As a method to prevent this halation,
A technique of adding a light-absorbing material, such as the method described in Japanese Patent No. 3756, is known. However, when using a solvent-based resist, it is necessary to pre-bake the applied photoresist to eliminate residual solvent, so depending on the type of light-absorbing agent, the light-absorbing agent may precipitate during storage or sublimate during pre-baking. There were problems such as the concentration being lowered and a satisfactory effect not being obtained, and variations occurring.

In order to further improve the above problem, light absorbing agents were investigated, and the use of phenylazobenthesi derivatives disclosed in JP-A-55-3683 and benzylidene storage dyes disclosed in JP-A-61-93445 were investigated. Proposed. When these compounds are used, raising the pre-baking temperature may result in insufficient sublimation resistance, broad absorption and low absorption ability, absorption in unnecessary areas, or In order to obtain the concentration of .tau., the resist performance such as sensitivity varies due to the large influence of the baking conditions.

[Problem to be solved by the invention]

An object of the present invention is to provide a photoresist composition that is highly sensitive, does not deteriorate resist performance due to prebaking conditions, has a high antihalation effect, and can form a resist pattern with high resolution.

[Means to solve the problem]

The present invention was made based on the knowledge that the above object can be achieved by incorporating at least one of the compounds represented by the following general formula (I) into a photoresist.

That is, the present invention provides a photoresist composition containing at least one compound represented by general formula (I).

(In the formula, R' and R2 are an alkyl group having 1 to 16 carbon atoms, a phenyl group, an aralkyl group, a cyclohexyl group, an alkoxyalkyl group, a tetrahydrofurfuryl group, or hydrogen, R3
is an alkyl group having 1 to 8 carbon atoms, an acetyl group, or hydrogen, R
4 represents an alkyl group having 1 to 4 carbon atoms, halogen, an alkoxy group, or hydrogen, and R5 represents an alkyl group having 1 to 4 carbon atoms or hydrogen. ) In the above general formula (I), R', R
The alkyl group of 2 preferably has 1 to 8 carbon atoms, the aralkyl group preferably has 8 to 10 carbon atoms, and the alkyl group of the alkoxyalkyl group preferably has a methyl or ethyl group. Furthermore, the alkyl group for R3 is preferably one having 1 to 4 carbon atoms, and the alkoxy group for R4 is preferably one having 1 to 4 carbon atoms.

Specific examples of the compound of general formula (I) include the following (I) to (
Examples include, but are not limited to, compounds I8). Incidentally, these compounds can be used alone or in combination of two or more.

Compound (I) Compound (2) Compound Compound Compound Compound Compound λmax 64 nm Compound (9) Compound (I0) Compound (I1) Compound (I2) Compound (I3) Compound (I4) Compound (I5) 2- (4'- N,N-dibutylamino-2'-hydroxy-5'-chlorobenzoyl)benzoic acid 2- (4'-N-benzylamino-2'-hydroxy-4'-methoxy-benzoyl)benzoic acid 2- (4'-N,N-dimethylamino-2'-hydroxy-5'-tert-butyl-benzoyl)benzoic acid 2 (4'-N-pendiylamino-2'-hydroxy-5'-chlorobenzoyl)benzoic acid 4- (4'-N-paratolylamino-2'-hydroxybenzoyl) Butyl benzoate 2- (4'-N-hexylamino-2'-butoxybenzoyl) Benzoate 3- (4'-N,N-dimethylamino -2'-methoxy-5'chlorobenzoyl)butyl benzoate compound (I6) 2- (4' -N ethoxyethylamino-2'-hydroxybenzoyl) benzoic acid compound (I7) 2- <4' -N, N Dibutylamino-2'-octoxybenzoyl)benzoic acid compound (I8) 2-(4'pendiylamino-2'
-Hydroxy-5-chlorobenzoyl)benzoic acid The absorption maximum in a solution of compounds (9) to (I8) is 350 to 380 nm, and as a light absorbing agent, λmax (solution Medium) value is preferably 380 nm or less.

The compound of the present invention can be easily synthesized by a known method such as adding m-alkylaminophenol and phthalic anhydride to an organic solvent and refluxing it, or by combining m-alkylaminophenol and a dicarboxybenzene derivative. Although it can be easily synthesized by a Dell-Crafts reaction, it is not necessarily limited to this method.

The compound represented by the general formula (I) can be added in an amount of 90.1 to 20% by weight in the photoresist composition. More preferably, it is added in an amount of 0.1 to 10% by weight. Further, the addition method may be such that it is added directly to the photoresist composition, or it may be added to the photoresist composition after being dissolved in a photoresist solvent.

The photoresist used as the base material of the photoresist composition used in the present invention is Polymer Engineering Science (Polymer Eng i 5ci) 20
(I980) 1087, a rubber-based photoresist containing cyclized rubber and bisazide as main components, and JP-A No. 6
2-36657 or U.S. Pat. No. 3,666,473 as a positive photoresist containing at least one 0-quinonediazide compound or J,
Blectrochen+ Sac, 118 (I97
1) 669.180 Journal, 12 (I9
68) 251, Electronic materials, 1980 separate volume (I980
) p, 83 and PoIymerEng l 5ci14
(I974) 518, deep UV resists containing polymethyl methacrylate and polydimethylglutarimide as main components, and the like.

〔Effect of the invention〕

The compound of general formula (I) used in the present invention is easily dissolved in organic solvents such as xylene, ethyl cellosolve, cyclohexanone, cellosolve acetate, butyl acetate,
It has good compatibility with rubber photoresists, positive type photoresists, and deep UV resists, and does not show sublimation even at high temperatures. Therefore, a composition containing these compounds has excellent line width controllability even on a highly reflective substrate, has excellent sensitivity, resolution, and sublimation resistance, and can provide fine patterns with good reproducibility.

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Synthesis Example 1 Synthesis of 2-(4'-N,N-dibutylamino-2'hydroxybenzoyl)benzoic acid 41 g of m-dibutylaminophenol and 44 g of phthalic anhydride were added to 100 g of toluene, and after refluxing for 10 hours. , sodium hydroxide 25g
300mj of water! Dissolve and add toluene, heat up to 80℃ and add 100mj of toluene! After stirring, the mixture was cooled to room temperature and filtered. 100 g of methanol was added to the filtrate, stirred, and filtered again to obtain 50 g of a pale pink solid.

By recrystallizing this crude product with ethanol, 2(4
'-N,N-dibutylamino-2-hydroxybenzoyl)benzoic acid was obtained as white crystals with a melting point of 189-189.4°C.

Example 1 Compound (I) of the present invention was added as a light absorbing agent to a positive photoresist FH-6100 (trade name, manufactured by Fuji Hunt Electronics Technology Co., Ltd.) containing a novolak resin and at least one O-quinone diazide. A photoresist was prepared by adding 0.5% by weight.

This photoresist composition was applied to a silicone wafer coated with aluminum using a spinner, and dried at 100°C for 30 minutes in a convection oven under a nitrogen atmosphere to a film thickness of 1.2.
A μ photoresist was obtained.

After exposing this film using a reduction projection exposure device, HPR
After developing with D-429E (trade name, manufactured by Fuji Hunt Electronics Technology Co., Ltd.) developer for 1 minute, it was washed with water for 30 seconds and dried. The resist pattern thus obtained was observed with a scanning electron microscope to evaluate the characteristics of the resist.

The results are shown in Table 1.

Example 2 For the same FH-6100 used in Example 1,
095% by weight of compound (2) represented by general formula (I)
, 0.4% by weight of compound (3), or 0% of compound (4)
．． A photoresist composition was prepared in the same manner as in Example 1, except that 4% by weight was dissolved, and evaluated in the same manner as in Example 1. The results are summarized in Table 1.

Example 3 Same as Example 1 except that 0.5% by weight of compound (5) or 0.3% by weight of compound (6) was dissolved in the same FH-6100 used in Example 1. The photoresist composition was adjusted and evaluated. The results are shown in Table 1.

Comparative Example When compound (I) is not used in Example 1 (Comparative Example 1), the following comparative compound I O, 4% by weight or ■06
A photoresist composition was prepared in the same manner as in Example 1 except that 5% by weight was used (Comparative Example 2.3), and the performance was measured. The results are shown in Table 1.

Comparative Compound ■ Comparative Compound ■ In Table 1, sensitivity indicates the exposure dose that reproduces a 1.0 μm mask pattern, and resolution indicates the limit resolution at the exposure dose that reproduces a 1.5 μm mask pattern. Further, sublimation resistance is expressed as the absorbance ratio at 365 nm (compared to before prebaking) determined by a spectrophotometer after applying the resist composition to a glass wafer and prebaking it at 100° C. for 30 minutes in a convection oven. The antihalation ability is the result of observing the resist pattern with a scanning electron microscope and examining the side surfaces of the pattern.

From the results shown in Table 1, it is clear that the photoresist composition of the present invention was excellent in sensitivity, resolution, sublimation resistance, and antihalation effect. Further, even when the solution of the photoresist composition of the present invention was left at 40° C. for 30 days, no precipitation of the light absorbing agent was observed in the resist solution.

On the other hand, although the line width of the minimum pattern obtained in Comparative Example 1 was 0.4 μm, the influence of halation was large, and the jaggedness on the side surfaces of the pattern was noticeable.

The minimum pattern line width obtained in Comparative Example 2 was 0.55 μm, and there were no jagged edges on the side surfaces of the pattern. However, the sensitivity was extremely low, the absorbance ratio was 0.80, and the sublimation resistance was poor.

The photoresist obtained in Comparative Example 3 had low sensitivity, the minimum pattern line width obtained was 0.55 μm, and the jaggedness on the side surfaces of the pattern was not so noticeable. However, 40℃
When the resist solution was left for 301 days, precipitation of the light absorbing agent was observed in the resist solution.

Claims (1)

[Scope of Claims] A photoresist composition containing at least one compound represented by general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) (In the formula, R^1 and R^2 are alkyl groups with 1 to 16 carbon atoms,
phenyl group, aralkyl group, cyclohexyl group, alkoxyalkyl group, tetrahydrofurfuryl group or hydrogen,
R^3 is an alkyl group, acetyl group, or hydrogen having 1 to 8 carbon atoms, R^4 is an alkyl group, halogen, alkoxy group, or hydrogen having 1 to 4 carbon atoms, and R^5 is an alkyl group having 1 to 4 carbon atoms. Or hydrogen. )