JPH02262546A - Styryl-based compound, its production and photoresist composition characterized by containing the same - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I [R1 is (substituted) 1 to 10C alkylene; R2 and R3 are H, (substituted) 1 to 4C alkyl, 1 to 4C alkoxy, halogen, OH or OCOR (R is 1 to 4C alkyl); X and Y are electron attractive group]. USE:A photoresist composition, especially suitably used in forming fine patterns on a substrate having a high reflectance in producing semiconductor devices and stable to prebaking with hardly any deterioration in sensitivity by addition of a light absorber thereto. PREPARATION:A compound expressed by formula II and a compound expressed by formula III are subjected to condensing reaction in the presence of an organic base catalyst in an inert organic solvent to provide a compound expressed by formula IV, which is then hydrolyzed with an acid to afford the compound expressed by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a styryl compound, a method for producing the same, and a photoresist composition containing the same.

More specifically, it relates to a photoresist composition that is particularly suitable for forming fine patterns on high reflectance substrates such as aluminum in the production of semiconductors and devices such as ICs and LSIs. 2. Description of the Related Art In the manufacture of integrated circuits such as LSIs, photoresists made of a quinone diazide photosensitizer and a novolak resin, photoresists made of a bisazide photosensitizer and a cyclized rubber resin, and the like are used.

When manufacturing integrated circuits, photoresists are used to form fine patterns on various substrates. However, on high-reflectivity substrates such as aluminum, aluminum-silicon, and polysilicon, conventional photoresists cannot be used to form fine patterns on the substrate surface or on uneven surfaces. Unnecessary photo-sensitivity occurs in areas due to reflection of light on the side surfaces, resulting in a problem called notching 1 halation.

For this reason, Japanese Patent Publication No. 51-37562 discloses a dye (Oil Yellow (C, I, -11020
) ) as a light-absorbing agent to reduce the light transmittance of the photoresist layer, sharply reducing the light that is reflected on the substrate surface and transmitted through the photoresist layer, and reducing the amount of light that goes around to the light-blocking area. A photoresist composition has been proposed that improves the above problem and prevents a decrease in resolution.Hereinafter, in the present invention, a composition consisting of a resin such as a novolak resin and a photosensitizer will be referred to as a "photoresist". good,
This material containing the light absorbing agent is referred to as "Photoresist composition J".

However, the addition of a light absorbing agent generally causes an undesirable problem in that the sensitivity of the photoresist is significantly reduced, reducing productivity during semiconductor manufacturing. However, depending on the light absorbing agent, it may precipitate during storage or sublimate during prebaking and reduce its concentration, making it unsatisfactory and resulting in variations in product quality. Additionally, JP-A No. 61-93445 discloses a photoresist composition using a styryl compound similar to the compound used in the present invention as a light absorbing agent, but in this case, the Although the problems of reduced performance and variations were resolved, there was a feeling that a significant drop in photoresist sensitivity would not be avoided.

<Problems to be Solved by the Invention> The present inventors have made extensive studies to overcome the drawbacks of the above-mentioned prior art, and as a result, have completed the present invention.

That is, an object of the present invention is to eliminate the drawbacks of the prior art and to form a high-resolution pattern on a high reflectance substrate that is free from halation and notching and is stable against pre-baking. An object of the present invention is to provide a highly sensitive photoresist composition in which sensitivity decreases little due to addition.

Another object of the present invention is to have good compatibility with the photoresist, and to ensure that the light absorbing agent has good compatibility with the photoresist during storage (in the photoresist composition).
It is an object of the present invention to provide a photoresist composition for microfabrication that does not precipitate (in a photoresist composition film after coating and prebeta).

Means for Solving the Problems〉 As a result of intensive studies, the present inventors have determined that the general formula (
The inventors have discovered that by using the compound represented by I), the drawbacks of the prior art can be solved all at once, and have completed the present invention.

(In the formula, RI has 1 to 1 carbon atoms, which may be further substituted.
10, more preferably 1 to 5 alkylene groups, R2 and Rs are hydrogen atoms, and optionally substituted carbon atoms 1
-4 alkyl group, C1-4 alkoxy group, halogen atom, hydroxy group, -0COR, and R represents a C1-4 alkyl group. X and Y each independently represent an electron-withdrawing group. Here, as the electron-withdrawing group, for example, SL Rs, SOs
R4 to Rs represent a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or a phenyl group, and R1 to R7 represent an optionally substituted alkyl group having 1 to 4 carbon atoms. Or represents a phenyl group. ) Furthermore, in addition to the above general formula (I), it has been found that compounds in which R2 and Rs are hydrogen atoms, and X and Y are cyano groups are particularly useful as light absorbers.

The compound represented by the general formula (1) of the present invention has the formula (I[
) (In the formula, RI has 1 to 1 carbon atoms which may be further substituted.)
0 alkylene group, R2 and Rs are hydrogen atoms,
Optionally substituted alkyl group having 1 to 4 carbon atoms, 1 carbon number
~4 alkoxy group, halogen [child -0COR], and R represents an alkyl group having 1 to 4 carbon atoms. ) and the general formula (I[[) (wherein, X, Y
each independently represents an electron-withdrawing group. ) It can be produced by condensing a compound represented by the following formula and then hydrolyzing it with an acid.

The condensation reaction is carried out in an inert organic solvent, such as ethanol,
The reaction is carried out using n-furopanol, toluene, chlorobenzene, chloroform, dimethylformamide, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, acetonitrile, acetic anhydride, or the like.

The compound represented by the general formula (n) and the general formula (I
The compound of II) is mixed in the inert organic solvent and a catalyst is added, in particular an organic base such as piperidine, pyridine, triethylamine or a mixture of piperidine and glacial acetic acid; Preferably 20~
0.5 at 80°C. Allow to react for ~20 hours, preferably 1-10 hours. Then, by distilling off the solvent from the reaction mixture, and if necessary, further extraction with an organic solvent and water,
By removing the solvent, a compound represented by the general formula (rV) (wherein RI SR1, R3, and X%Y have the above-mentioned meanings) is obtained.

The hydrolysis is carried out using acids such as inorganic acids such as hydrochloric acid and sulfuric acid, aliphatic carboxylic acids such as acetic acid and trichloroacetic acid, and sulfonic acids such as toluenesulfonic acid and benzenesulfonic acid.

The compound represented by the general formula (IV) and an acid are mixed in an inert organic solvent, such as ethanol, methanol, n-propanol, etc., and heated at 20 to 100°C, preferably 60 to 80°C, for 0. 5-5 hours, preferably 0.5-5 hours
Let react for 2 hours. Then, by charging the reaction mixture into a large excess of ion-exchanged water, a crude cake of the compound represented by the general formula "(I)" is precipitated. After filtration, washing if necessary, and drying, reconstitution from an appropriate solvent is performed. The general formula (
A purified cake of the compound shown in 1) is obtained.

As the photoresist serving as the base material of the photoresist composition used in the present invention, for example, one consisting of a novolak resin obtained by addition-condensation reaction of phenols and formaldehyde and a naphthoquinone diazide compound is suitably used. Among them, cresol novolak resin synthesized from m-cresol and/or p-cresol and formalin, or cresol novolac resin synthesized from m-, p-cresol, 3.5-xylenol and formalin, etc. 2.3.4 -) lyhydroxybenzophenone, 2,3,4.4'-tetrahydroxybenzophenone, 2.2',4.4'tetrahydroxybenzophenone, 2.3.3'4-tetrahydroxybenzophenone, 2,23. 4.5-pentahydroxybenzophenone, 2.3.3', 4.5-pephtahydroxybenzophenone, 2.3.3', 4.4'-pentahydroxybenzophenone, 2.2', 3.4° The present invention preferably uses a photoresist containing naphthoquinone-1,2-diazide sulfonic acid ester of polyhydroxybenzophenones such as 4'-pentahydroxybenzophenone, 2.23.3', 4-pentahydroxybenzophenone, etc. The general formula (
The amount of the compound (dye) represented by I) is usually 0.1 to 20%, more preferably 0.2 to 10%, based on the solid content of the photoresist. If this amount is too small, the antihalation effect will be low, and if it is too large, the profile and sensitivity will tend to deteriorate. Furthermore, in the composition of the present invention, in addition to the specific styryl dye of the present invention, one or more other dyes may be used in combination.

Among these dyes of the present invention, in particular 550 nm or less,
More preferably, a compound (dye) having an absorption maximum for light in a region of 300 to 450 nm is preferably used.

<Effects of the Invention> According to the present invention, the shortcomings of the prior art are eliminated at once, and high-resolution patterns without halation or notching can be stably produced even on high-reflectance substrates without reducing productivity. Its industrial utility value is immeasurable, such as being able to form

<Examples> Hereinafter, the present invention will be specifically explained using Examples, but the present invention is not limited thereto.

Example 1 β-anilinoethanol 25.0 g, allyl chloride 2
Mix 5rnl, anhydrous sodium carbonate, and 9.7g of
The reaction was stirred at 5 to 27°C for 2 days. Filter the reaction solution,
By concentrating the filtrate, 31.6 g of N-allyl-N-2-hydroxyethylaniline was obtained.

Next, 31.6 g of N-allyl-N-2-hydroxyethylaniline, 20.0 g of acetic anhydride, and No. gin 1- were mixed, and the mixture was stirred and reacted at 25 to 27°C for 15 hours. Methyl alcohol 8- was added to the reaction solution and stirred at 25-27°C for 30 minutes. Add ethyl acetate to the reaction solution.
, 200rnl of water was added and the extraction was repeated twice, and the upper layer was concentrated to obtain 36.9 g of N-allyl-N-2-acytethylaniline.

Next, N
-Allyl-N-2-acetoxyethylaniline 36.9
g was added dropwise over 30 minutes, and then stirred at 60°C for 6 hours. This reaction solution was discharged into 150 rnl of water, neutralized with an aqueous sodium hydroxide solution, and then 100 rnl of ethyl acetate was added. The extraction was repeated twice.

By concentrating the upper layer, the following formula (1) 29.9 g of the compound represented by was obtained.

Next, 29.9 g of the compound represented by formula (1) and 8.79 g of malononitrile were mixed in 80 ml of ethyl alcohol and stirred at 70°C for 6 hours. After distilling off the ethyl alcohol from this mixture, 100 ml of ethyl acetate was added. mf,
Water 200rd! was added and the extraction was repeated twice. The upper layer-
By condensation, 32.1 g of a compound represented by the following formula (2) was obtained.

Next, 32.1 g of the compound represented by formula (2) was dissolved in 40% of ethyl alcohol, and the solution was dissolved at 75 to 78°C to a concentration of 36%.
11.9 g of hydrochloric acid was added dropwise over 5 minutes. 1 at 75-78℃
After stirring for an hour, the reaction solution was poured with 120mj of ion-exchanged water! I charged it. By filtering and drying the reaction solution, 26.7 g of a crude cake of the compound represented by the following formula (3) was obtained.

Next, the compound represented by formula (3) was added to 180 f toluene.
fLl! After dissolving at 80°C, the mixture was cooled to 25-26°C and recrystallized. 'By filtering and drying, the formula (3
) purified cake 16, Og was obtained.

Absorbance in ethyl cellosolve acetate solution λrna
x: 430rlTTL.

ε:6.23
H.

t) , 4.23 (2H, d) , 5.17 (2H
, m), 5.90 (IH, m), 6.90 (2H
,d) ,7.80 (IH,S') ,7.85 (
2H, d).

Melting point: 99-100° C. The compounds shown in Table 1 were produced in the same manner as in Example 1.

(Space below) Example 12 and Comparative Example 1.2 Positive photoresist PF-6200 containing novolac resin and at least one 0-quinone diazide (trade name, manufactured by Sumitomo Chemical @, solid content ratio 31.0 wt%) ) were added to each compound shown in Table 2 to prepare a photoresist composition. The amount of the compound added was 0.68 wt% based on the solid content of PF-6200.

These photoresists were spin-coated onto a 4-inch silicon wafer coated with an aluminum film using a spinner to a film thickness of 1.80 μm, and prebaked on a hot plate at 100° C. for 1 minute. This is converted into a reduction projection exposure system by changing the exposure amount step by step through a test reticle.
505G). This was developed using 5OPD (trade name, manufactured by Sumitomo Chemical Co., Ltd., positive type developer) in an automatic developing machine by the static paddle method at 23° C. for 60 seconds.

The results are shown in Table-2.

(Hereinafter referred to as a margin) (hereinafter referred to as a margin) As shown in Table 2, a pattern could be formed with high sensitivity in the example. The formed pattern was sharply resolved down to 0.8 μm, and there was no notching due to reflected light from the side surfaces of the pattern, indicating that the pattern was excellent in preventing halation from the aluminum surface.

In addition, the same composition was spin coated on a glass wafer in the same manner as on an aluminum wafer, prebaked in a competition oven at 120°C for 30 minutes, and measured with a UV-visible spectrum meter at 436nm absorbance ratio (comparison with before prebaking, photosensitive When the amount of thermal decomposition of the agent was removed, it was found to be close to 1, indicating good sublimation resistance.

A silicon wafer was exposed in the same manner as above, afterbaked in a convection oven at 90° C. for 30 minutes, stored for 4 days, and then developed. Precipitates remaining between the patterns were examined, but no precipitates were observed. No light absorbing agent was deposited in the resist after 6 months of storage (at 23° C.).

On the other hand, the photoresist of the comparative example has a sensitivity, It was unsatisfactory in terms of sublimation resistance.

(Margin below)

Claims (5)

[Claims] (1) A compound represented by general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 is a carbon number of 1 to 10 that may be further substituted.
represents an alkylene group, R_2 and R_3 are hydrogen atoms,
Optionally substituted alkyl group having 1 to 4 carbon atoms, 1 carbon number
~4 alkoxy group, halogen atom, hydroxy group, -
OCOR is represented, and R represents an alkyl group having 1 to 4 carbon atoms. X and Y each independently represent an electron-withdrawing group. ) (2) The compound according to claim 1, wherein in the general formula (I), R_2 and R_3 are hydrogen atoms, and X and Y are cyano groups. (3) Compound represented by general formula (II) ▲ Numerical formula, chemical formula, table, etc. ▼ (II) (In the formula, R_1 has 1 to 10 carbon atoms which may be further substituted.
represents an alkylene group, R_2 and R_3 are hydrogen atoms,
Optionally substituted alkyl group having 1 to 4 carbon atoms, 1 carbon number
~4 alkoxy group, halogen atom, ▲ mathematical formula, chemical formula,
▼ represents an alkyl group having 1 to 4 carbon atoms. ) and a compound represented by the general formula (III) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) (In the formula, X and Y each independently represent an electron-withdrawing group.) After reacting with A method for producing the compound according to claim 1, which comprises hydrolyzing the compound with an acid. (4) A photoresist composition comprising the compound according to claim 1. (5) A photoresist composition comprising the compound according to claim 1, wherein R_2 and R_3 are hydrogen atoms, and X and Y are cyano groups.