JP3499088B2 - Salicylic acid aralkyl resin, method for producing the same, and resin composition for photoresist using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel salicylic acid aralkyl resin. More specifically,
The present invention relates to a salicylic acid aralkyl resin having a high resolution as an alkali-soluble component in a photoresist material and enabling fine processing, a method for producing the same, and a photoresist resin composition using the same.

[0002]

2. Description of the Related Art Conventionally, as an alkali-soluble resin for a photoresist material used in a semiconductor device manufacturing process such as IC and LSI, phenol, which is the most general-purpose phenol resin, or a condensate of cresol and formalin, a so-called novolak resin, is used. It is used, and a resin composition for photoresist is constituted by using quinonediazide sulfonate as a photosensitizer. In the normal state, the resin composition for photoresists is in a state where the alkali solubility of the composition is largely inhibited by the quinonediazide sulfonic acid ester. When irradiated with light having a wavelength of about 300 to 500 nm, quinonediazide decomposes and loses its inhibitory effect, and itself produces an alkali-soluble carboxyl group, resulting in a difference in alkali-solubility between the non-irradiated portion and the irradiated portion. . Utilizing this fact, the photoresist resin composition has been widely used as a positive resist.
However, recent integrated circuits such as ICs and LSIs have been highly integrated, and accordingly, higher sensitivity and resolution are required so that the photoresist can be finely processed. Therefore, the conventional resin composition for photoresists using novolac resin has a sensitivity and a resolution that are already close to their limits, and has been further improved in the production of a semiconductor memory having a higher integration degree, for example, 256M or more. Is being sought.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to produce an alkali semiconductor capable of satisfying the high resolution and high sensitivity required for a photoresist resin composition in producing a highly integrated semiconductor circuit. It is intended to provide a salicylic acid-based aralkyl resin as a soluble component, and to provide a photoresist resin composition using the same.

[0004]

Means for Solving the Problems The inventors of the present invention have made earnest studies to achieve the above-mentioned problems, and as a result, by using a certain type of salicylic acid aralkyl resin, a resin composition for photoresist having high resolution and high sensitivity. The present invention has been completed and the present invention has been completed. That is,
The present invention relates to a salicylic acid-based aralkyl resin represented by the general formula (1) (formula 5).

[0005]

[Chemical 5] [Wherein, X is a salicylic acid residue (A) or a bisphenol residue (B) represented by the following formula (2)
And the A / B molar ratio is 99/1 to 50/5.
0, and m represents an integer of 0 to 100]

[0006]

[Chemical 6] In addition, the present invention provides an aralkyl alcohol derivative or an aralkyl halide represented by the general formula (3) (Chemical formula 7) using methyl salicylate and a bisphenol represented by the formula (2) as a condensing agent in the presence of an acid catalyst. The present invention relates to a method for producing a salicylic acid-based aralkyl resin, which comprises co-condensing with a solvent, distilling off unreacted methyl salicylate, and subjecting the resulting ester of the resin to alkali hydrolysis.

[0007]

[Chemical 7] (In the formula, R ₁ represents a hydroxyl group, a lower alkoxy group having 4 or less carbon atoms, or a halogen atom.) Further, in the resin composition for photoresist containing an alkali-soluble resin and a photosensitizer, the present invention provides an alkali-soluble resin. The resin composition for photoresists, wherein the salicylic acid aralkyl resin is used as an essential component of the above, wherein the alkali-soluble resin contains the salicylic acid aralkyl resin in an amount of 1% by weight to 99% by weight. Resin composition for photoresist, alkali-soluble resin is salicylic acid aralkyl resin and phenol novolac, cresol novolac, phenol aralkyl resin represented by general formula (4) (chemical formula 8), general formula (5) (chemical formula 8) Represented by phenol-dicyclopentadiene co-condensation resin, hydroxypolystyrene or Contains at least one selected from hydrides thereof, and the photoresist resin composition according to any one of 1 to 3 above, wherein the photosensitizer is a quinonediazide sulfonic acid ester. Is related to.

[0008]

[Chemical 8] (In the above formula, R ₂ and R ₃ are each a hydrogen atom, a methyl group,
Represents a hydroxyl group or a halogen atom, n is 0 to 100, and l is 0
~ Represents an integer of 20)

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The salicylic acid aralkyl resin of the present invention is a novel resin represented by the above general formula (1). In the general formula (1), X represents either the salicylic acid residue (A) or the bisphenol residue (B) represented by the formula (2), and the A / B molar ratio is 99 /
1 to 50/50, and m is an integer of 0 to 100.
In the general formula (1), the residue of salicylic acid, the bisphenol represented by the formula (2) (hereinafter abbreviated as BPFL)
The residue of represents a monovalent or divalent group in which a hydrogen atom is removed from salicylic acid or BPFL, respectively.

In producing the salicylic acid aralkyl resin of the present invention, it is possible to use salicylic acid as a raw material as a salicylic acid source, and methyl salicylate, ethyl salicylate, isopropyl salicylate, n-butyl salicylate, isobutyl salicylate,
It is also possible to use salicylic acid esters such as tert-butyl salicylate, benzyl salicylate, and phenyl salicylate as raw materials, make them into resins, and then hydrolyze them to obtain salicylic acid. Particularly preferred is methyl salicylate, which is oily, easy to distill and recover unreacted components, and inexpensive.
The BPFL used in the present invention is commercially available and is easily available, and, for example, in the presence of an acid catalyst,
It can be produced by reacting 9-fluorenone with phenol.

The aralkyl alcohol derivative or aralkyl halide represented by the general formula (3), which serves as a condensing agent of (salicylic acid or salicylic acid ester) and BPFL, includes, for example, α, α'-dihydroxy-
p-xylene, α, α′-dihydroxy-m-xylene, α, α′-dihydroxy-o-xylene, α, α ′
-Dimethoxy-p-xylene, α, α'-dimethoxy-
m-xylene, α, α′-dimethoxy-o-xylene,
α, α′-diethoxy-p-xylene, α, α′-diethoxy-m-xylene, α, α′-diethoxy-o-xylene, α, α′-diisopropoxy-p-xylene,
α, α'-diisopropoxy-m-xylene, α, α '
-Diisopropoxy-o-xylene, α, α'-di-n
-Butoxy-p-xylene, α, α'-di-n-butoxy-m-xylene, α, α'-di-n-butoxy-o-
Xylene, α, α′-di-sec-butoxy-p-xylene, α, α′-di-sec-butoxy-m-xylene, α, α′-di-sec-butoxy-o-xylene,
α, α′-di-ter-butoxy-p-xylene, α,
α'-di-ter-butoxy-m-xylene, α, α '
-Di-ter-butoxy-o-xylene, α, α'-dichloro-p-xylene, α, α'-dichloro-m-xylene, α, α'-dichloro-o-xylene, α, α'-
Difluoro-p-xylene, α, α′-difluoro-m
-Xylene, α, α'-difluoro-o-xylene,
α, α′-dibromo-p-xylene, α, α′-dibromo-m-xylene, α, α′-dibromo-o-xylene, α, α′-diiodo-p-xylene, α, α′-diiodo -M-xylene, α, α′-diiodo-o-xylene and the like can be mentioned. Particularly preferred are α,
α'-dichloro-p-xylene, α, α'-dichloro-
m-xylene, α, α′-dihydroxy-p-xylene, α, α′-dihydroxy-m-xylene, α, α ′
-Dimethoxy-p-xylene, α, α'-dimethoxy-
Examples include m-xylene and the like. These may be used alone or as a mixture of two or more. In particular, the p-xylylene derivative and the m-xylylene derivative cause a large difference in physical properties such as the softening point and melt viscosity of the resin finally obtained, and thus it is possible to adjust the physical properties to some extent by the mixing ratio. .

In the production of the salicylic acid aralkyl resin of the present invention, (salicylic acid or salicylic acid ester) / BPFL used in the reaction has a molar ratio of 99.5 / 0.
5 to 70/30, preferably 99/1 to 75/2
The range is 5/5, more preferably 95/5 to 80/20. The molar ratio of [(salicylic acid or salicylic acid ester) + BPFL] / aralkyl compound is 1.
Range of 1/1 to 15/1, preferably 1.3 / 1 to 10
/ 1, and more preferably 1.3 / 1 to 5/1. If the molar ratio is closer to 1 than the above range, the polymer may have a high molecular weight and may sometimes be in the form of gel, which may make the production substantially impossible. On the other hand, when it is large, the heat resistance is lowered due to the decrease of the molecular weight, and the volume efficiency is industrially deteriorated due to the large amount of unreacted raw materials, which tends to be a cost disadvantage. In the production method of this reaction, unreacted salicylic acid or salicylic acid ester may remain, but in that case, it is desirable to remove it by any method such as vacuum distillation, washing with water, and washing with alkali. The unreacted components decrease as the molar ratio of [(salicylic acid or salicylic acid ester) + BPFL] / aralkyl compound approaches 1, so that it is not always necessary to remove it when it is determined that there is substantially no problem.

In the production method of the present invention, the reaction is carried out in the presence of an acid catalyst. Specific examples of the catalyst include mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid, organic acids such as p-toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid and diethylsulfate, aluminum chloride, iron chloride, tin chloride, Lewis acids such as boron trifluoride, perfluoroalkane sulfonic acids that are super strong acids such as trifluoromethane sulfonic acid, alkane sulfonic acid type ion exchange resins, and super strong acids represented by Nafion (trade name: DuPont) Examples thereof include perfluoroalkanesulfonic acid type ion exchange resins. These may be used alone or in admixture of two or more. Although the amount used depends on the kind, it is in the range of 0.0001% to 50% by weight, preferably 0.0001% to 1 in the case of perfluoroalkanesulfonic acid (super strong acid), based on the weight of all raw materials. In the case of mineral acids and Lewis acids, the range is 0.001% to 10% by weight, and in the case of ion exchange resins, the range is 1% to 50% by weight. When the aralkyl compound used in the reaction is an aralkyl halide, it is also possible to consider the hydrogen halide generated by the reaction as a catalyst, and when the amount is sufficient, the reaction is carried out with no apparent catalyst. It is also possible.

In the reaction, the use of a solvent which does not substantially participate in the reaction can be used. For example, aromatic solvents such as benzene, toluene, xylene, chlorobenzene, o-dichlorobenzene, N, N-dimethyl-2-imidazolidinone, N-methylpyrrolidone, N, N-dimethylformamide, sulfolane, dimethyl sulfoxide. An aprotic polar solvent or the like may be used in an arbitrary amount.
Strictly speaking, toluene, xylene, and the like react with an aralkyl compound in the presence of an acid catalyst, but the reaction rate thereof is generally much slower than that of phenols.
In the present reaction in the presence of salicylic acids and BPFL, it is negligible. However, if impurities such as toluene or xylene that are slightly mixed in the resin are inconvenient, it is better to avoid using them. Usually, when the salicylic acid to be used is a liquid such as methyl salicylate and can be sufficiently stirred without a solvent, and a uniform solution is formed, it is not necessary to use a solvent.

The reaction temperature is 80 to 250 ° C, preferably 100 to 200 ° C, more preferably 120 to 180 ° C.
Is the range. The reaction time is generally in the range of 1 to 30 hours until the aralkyl compound disappears, but in reality, the disappearance of the aralkyl compound is confirmed by high performance liquid chromatography or gas chromatography, or It is desirable to end the reaction at the time when the completion of the composition is confirmed by GPC (gel permeation chromatography). When salicylic acid ester is used as a raw material after completion of the reaction, the ester group needs to be hydrolyzed, but it may be introduced into a salicylic acid-based resin by hydrolysis with an ordinary acid or alkali. In particular, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are desirable.

The alkali metal hydroxide required for hydrolysis may be added in a small excess amount with respect to the ester group in the resin estimated from the recovered unreacted salicylic acid ester, but the alkali metal salt of the resin may be completely removed. In order to obtain an aqueous solution, it is better to use twice or more the amount of alkali metal hydroxide. When economic considerations are added, it is preferably in the range of 2.0 to 5.0 times equivalent, more preferably 2.1 to 3.0 times equivalent. If insoluble matter is generated at this stage, it is filtered off and neutralized to obtain the desired salicylic acid aralkyl resin. In practice, this resin can be washed until it becomes neutral and provided for the intended photoresist application. As for the washing method, sludge with water is simple, but the most preferable method is to make a solution using an organic solvent, wash with water, and separate the solution. The obtained salicylic acid aralkyl resin can be used as an ordinary phenol resin, for example, in a field such as an epoxy resin raw material or a curing agent for an epoxy resin, or molding, casting, adhesion, paint, etc. It exhibits extremely high performance when used as a resist material.

The photoresist resin composition of the present invention comprises:
A resin composition for a photoresist, which contains the salicylic acid-based aralkyl resin of the present invention as an alkali-soluble resin, and further contains a photosensitizer. In the photoresist resin composition of the present invention, the salicylic acid-based aralkyl resin of the present invention is used in an amount of 1% by weight to the alkali-soluble resin used.
It is contained in the range of 100% by weight. That is, various usage forms are possible, from the case where it is used alone as the base resin itself to the case where it is used as a sensitivity adjusting agent and an additive. In the photoresist resin composition of the present invention, as the alkali-soluble resin, the salicylic acid-based aralkyl resin of the present invention can be used together with other alkali-soluble resins.

Other alkali-soluble resins used include so-called novolaks, phenolic compounds and dicyclohexyl compounds obtained by reacting phenolic compounds such as phenol, cresol and naphthol with aldehydes in the presence of an acid catalyst. Phenol-dicyclopentadiene resin obtained by reacting with pentadiene, phenol aralkyl resin obtained by reacting a phenolic compound with an aralkyl alcohol derivative or aralkyl halide represented by the general formula (3), polyhydroxystyrene and Examples thereof include hydrides, styrene-maleic anhydride copolymers and polymethylmethacrylate.

As the photosensitizer, any photosensitizer may be used, but quinonediazide sulfonic acid ester is preferred.
The quinone diazide sulfonic acid may be one derived from quinone diazide sulfonic acid chloride and various phenols, for example, hydroquinone, resorcin, phloroglysin, 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone. ,
2,3,3 ′, 4-tetrahydroxybenzophenone,
2,3,4,4'-tetrahydroxybenzophenone,
Such as perhydroxybenzophenones, gallic acid alkyl esters, bis [(poly) hydroxyphenyl] such as 2,2-bis [(poly) hydroxyphenyl] propane
1,2-naphthoquinonediazide-4-sulfonic acid esters such as alkanes and oxyflavan, or 1,2-
Examples thereof include naphthoquinone diazide-5-sulfonic acid esters. The addition amount of the quinonediazide sulfonic acid ester is preferably in the range of 5 to 50% by weight based on the solid content of the photoresist resin composition. Further, the photoresist resin composition of the present invention may contain other small amounts of resins, sensitivity modifiers, dyes and the like, if necessary.

The photoresist resin composition of the present invention comprises:
Usually, it is generally applied by spin coating using an organic solvent, but the solvent used for this purpose has an appropriate boiling point and vapor pressure, that is, a drying rate, and evaporates the solvent. It is required to give an average and uniform coating when dried. As the solvent used, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethyl cellosolve acetate,
Methyl cellosolve acetate, diethylene glycol monoethyl ether, propylene glycol monopropyl ether acetate, toluene, xylene, propylene glycol, ethyl 2, -hydroxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, pyruvin Methyl acid,
Methyl 3-methoxypropionate, ethyl 3-methoxypropionate, butyl acetate, ethyl lactate, methyl isobutyl ketone, cyclohexanone, 2-heptanone, 3-
Examples include heptanone and 4-heptanone. These solvents may be used alone or in combination of several kinds. The concentration at this time is 5 to 75% by weight, preferably 10 to 50% by weight as a solid content concentration as a photoresist resin composition.
It is preferably in the range of 20% by weight, more preferably 20 to 40% by weight.

The thus prepared solution of the photoresist resin composition is preferably filtered with a filter to remove insoluble matter and fine dust before spin coating. Then, using a spin coater (rotary coating machine) or the like, coating is performed on a substrate such as a silicon wafer. Then, the substrate can be baked at 50 to 150 ° C. for 30 to 180 seconds, exposed through a photomask with an exposure machine, and developed with an alkaline aqueous solution to draw a pattern. The alkaline aqueous solution as the developer means sodium hydroxide, potassium hydroxide, sodium carbonate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n.
1-20% by weight of an alkaline compound such as propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, tetraammonium hydroxide, choline, piperidine, 1,8-diazabicyclo- (5,4,0) -7-undecene, It is preferably adjusted to 1 to 10% by weight and used.

The radiation used for the exposure is g
Line (426 nm), i-line (365 nm), Kr-F excimer laser (248 nm), etc. are used, but currently i-line or higher energy and higher resolution,
It is preferable to use an excimer laser capable of high sensitivity. The resin of the present invention can be applied not only to a positive photoresist but also to a so-called chemical amplification type exposure method.

[0023]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Example 1 A glass reactor equipped with a thermometer, a stirrer, a Dean-Stark water separator and a reflux condenser, methyl salicylate; 913.2 g (6 mol), BPFL; 105.
2 g (0.3 mol), trifluoromethanesulfonic acid;
0.25 mol was charged and the temperature was raised to 150 ° C. with stirring. Further, stirring was performed, and 332 g (2 mol) of α, α′-dimethoxy-p-xylene; was added dropwise over 4 hours while maintaining the temperature of 150 to 160 ° C. Methanol generated by the reaction was sequentially removed from the system by using a Dean-Stark water separator. The reaction was carried out under a small flow of nitrogen. After completion of the dropping, the mixture was aged for 2 hours while maintaining the same temperature, and after confirming that the distillation of methanol was completely eliminated, unreacted methyl salicylate was distilled off under the conditions of 170 ° C. and 5 mmHg at maximum. The recovered amount of methyl salicylate was 120 g. When the obtained methyl salicylate-BPFL resin was analyzed by high performance liquid chromatography, unreacted BPFL monomer was not detected. To this methyl salicylate-BPFL resin, 300 g of toluene was added to form a uniform toluene solution. This toluene solution was added dropwise to an aqueous solution of 320 g (8 mol) of sodium hydroxide and 1600 g of water over 3 hours while maintaining 85 to 95 ° C. The azeotropic toluene / water was removed to the outside of the system. After aging for 2 hours, when methyl salicylate was hydrolyzed, a uniform aqueous solution was obtained and there was no insoluble matter. This alkaline aqueous solution was added dropwise to 2000 g of hydrochloric acid water containing 8.8 mol of hydrochloric acid over 4 hours and neutralized to precipitate a resin in powder form. After the completion of dropping, it was confirmed that the solution was acidic, and the slurry was further aged for 2 hours for aging. After that, the mixture was filtered, and the slurry was washed with 1500 g of water three times to confirm that the filtrate became neutral, and then dried to obtain 550 g of a salicylic acid aralkyl resin as a powder. The molecular weight (Mw) of this resin by GPC (gel permeation chromatography) was 4,600 (in terms of polystyrene, the same applies hereinafter).

Example 2 In a glass reactor equipped with a thermometer, a stirrer, a Dean-Stark water separator and a reflux condenser, methyl salicylate; 913.2 g (6 mol), BPFL; 26.4
g (0.08 mol), trifluoromethanesulfonic acid;
0.05 mol was charged and the temperature was raised to 150 ° C. with stirring. With further stirring, while maintaining the temperature of 150 to 160 ° C., α, α′-dimethoxy-p-xylene;
332 g (2 mol) was added dropwise over 4 hours. Methanol generated by the reaction was sequentially removed from the system by using a Dean-Stark water separator. The reaction was carried out under a small flow of nitrogen. After completion of the dropping, the mixture was aged for 2 hours while maintaining the same temperature, and after confirming that the distillation of methanol was completely eliminated, unreacted methyl salicylate was distilled off under the conditions of 170 ° C. and 5 mmHg at maximum. The recovered amount of methyl salicylate was 107 g. Methyl salicylate obtained-
When the BPFL resin was analyzed by high performance liquid chromatography, unreacted BPFL monomer was not detected. To this methyl salicylate-BPFL resin, toluene 3
00 g was added to obtain a uniform toluene solution. This toluene solution was added to an aqueous solution of 320 g (8 mol) of sodium hydroxide and 1600 g of water while maintaining 85 to 95 ° C.
It was added dropwise in 3 hours. The azeotropic toluene / water was removed to the outside of the system. After aging for 2 hours, when methyl salicylate was hydrolyzed, a uniform aqueous solution was obtained and there was no insoluble matter. This alkaline aqueous solution was added with hydrochloric acid water 200 containing 8.8 mol of hydrochloric acid.
The resin was dropped in 0 g for 4 hours and neutralized to precipitate the resin in powder form. After the completion of dropping, it was confirmed that the solution was acidic, and the slurry was further aged for 2 hours for aging. After this, filter,
Further, the slurry was washed with 1500 g of water three times, and it was confirmed that the filtrate became neutral, and then dried to obtain 550 g of a salicylic acid aralkyl resin as a powder. The molecular weight of this resin by GPC (gel permeation chromatography) (M
w) was 1070.

Example 3 In a glass reactor equipped with a thermometer, a stirrer, a Dean-Stark water separator and a reflux condenser, methyl salicylate; 913.2 g (6 mol), trifluoromethanesulfonic acid; 0.25 mol Charge and stir 1
The temperature was raised to 50 ° C. Further stirring, 150-16
While maintaining the temperature of 0 ° C, α, α'-dimethoxy-p-
Xylene; 332 g (2 mol) and BPFL; 105.
A mixed solution of 2 g (0.3 mol) was added dropwise over 4 hours.
Methanol generated by the reaction was sequentially removed from the system by using a Dean-Stark water separator. The reaction was carried out under a small flow of nitrogen. After completion of the dropping, the mixture was aged for 2 hours while maintaining the same temperature, and after confirming that the distillation of methanol was completely eliminated, unreacted methyl salicylate was distilled off under the conditions of 170 ° C. and 5 mmHg at maximum. The recovered amount of methyl salicylate was 120 g. When the obtained methyl salicylate-BPFL resin was analyzed by high performance liquid chromatography, unreacted BPFL monomer was not detected. To this methyl salicylate-BPFL resin, 300 g of toluene was added to obtain a uniform toluene solution. This toluene solution was added dropwise to an aqueous solution of 320 g (8 mol) of sodium hydroxide and 1600 g of water over 3 hours while maintaining 85 to 95 ° C. The azeotropic toluene / water was removed to the outside of the system. After aging for 2 hours, when methyl salicylate was hydrolyzed, a uniform aqueous solution was obtained and there was no insoluble matter. This alkaline aqueous solution was added dropwise to 2000 g of hydrochloric acid water containing 8.8 mol of hydrochloric acid over 4 hours and neutralized to precipitate a resin in powder form. After the completion of dropping, it was confirmed that the solution was acidic, and the slurry was further aged for 2 hours for aging. After that, it is filtered, and the slurry is washed with 1500 g of water three times,
After confirming that the filtrate became neutral, it was dried to obtain 550 g of a salicylic acid aralkyl resin as a powder. GP of this resin
The molecular weight (Mw) by C (gel permeation chromatography) was 3230.

Example 4 In a glass reactor equipped with a thermometer, a stirrer, a Dean-Stark water separator and a reflux condenser, methyl salicylate; 913.2 g (6 mol), trifluoromethanesulfonic acid; 0.05 mol Charge and stir 1
The temperature was raised to 50 ° C. Further stirring, 150-16
While maintaining the temperature of 0 ° C, α, α'-dimethoxy-p-
Xylene; 332 g (2 mol) and BPFL; 26.4
A mixed solution of g (0.08 mol) was added dropwise over 4 hours.
Methanol generated by the reaction was sequentially removed from the system by using a Dean-Stark water separator. The reaction was carried out under a small flow of nitrogen. After completion of the dropping, the mixture was aged for 2 hours while maintaining the same temperature, and after confirming that the distillation of methanol was completely eliminated, unreacted methyl salicylate was distilled off under the conditions of 170 ° C. and 5 mmHg at maximum. The recovered amount of methyl salicylate was 107 g. When the obtained methyl salicylate-BPFL resin was analyzed by high performance liquid chromatography, unreacted BPFL monomer was not detected. To this methyl salicylate-BPFL resin, 300 g of toluene was added to obtain a uniform toluene solution. This toluene solution was added dropwise to an aqueous solution of 320 g (8 mol) of sodium hydroxide and 1600 g of water over 3 hours while maintaining 85 to 95 ° C. The azeotropic toluene / water was removed to the outside of the system. After aging for 2 hours, when methyl salicylate was hydrolyzed, a uniform aqueous solution was obtained and there was no insoluble matter. This alkaline aqueous solution was added dropwise to 2000 g of hydrochloric acid water containing 8.8 mol of hydrochloric acid over 4 hours and neutralized to precipitate a resin in powder form. After the completion of dropping, it was confirmed that the solution was acidic, and the slurry was further aged for 2 hours for aging. After that, it is filtered, and the slurry is washed with 1500 g of water three times,
After confirming that the filtrate became neutral, it was dried to obtain 550 g of a salicylic acid aralkyl resin as a powder. GP of this resin
The molecular weight (Mw) by C (gel permeation chromatography) was 1230.

Example 5 17 parts by weight of the resin obtained in Example 1, 5 parts by weight of a diester synthesized by a conventional method from naphthoquinonediazide-4-sulfonic acid chloride and 4,4'-dihydroxybenzophenone as a photosensitizer. Was dissolved in 48 parts by weight of ethyl cellosolve acetate to obtain a resist solution. 0.2μ
This solution filtered through a Teflon filter of m was applied to a well-washed silicon wafer by a spin coater to a thickness of 1.2 μm and baked in an oven at 100 ° C. for 60 seconds. Then, a reduction projection exposure machine (manufactured by Nikon Corporation: NSR-17551i7A NA = 0.0.5) having an exposure wavelength of 365 nm (i-line) was applied to this silicon wafer.
50). Then, it baked for 1 minute in the oven maintained at 110 degreeC. A positive pattern was obtained by developing this with a 2.4% by weight aqueous solution of tetramethylammonium hydroxide for 1 minute. The obtained resist pattern was evaluated by the following methods. The evaluation results are shown in Table-1 (Table 1).

<< Resist Evaluation Method >> Sensitivity: Change the exposure time of the reduction projection exposure machine to 365
nm (i-line) exposure and then 60% at 25 ° C. with a 2.4% by weight aqueous solution of tetramethylammonium hydroxide.
After development for 2 seconds, a positive type resist was formed on a silicon wafer. The optimum exposure time (exposure time for generating a line-and-space pattern (1L1S) having a line width of 0.35 μm in a width of 1: 1) was defined as the sensitivity.・ Resolution: The size of the smallest resist pattern resolved when exposed with the optimum exposure time is taken as the resolution, and the size equivalent to the comparative example is △, the smaller size is ○, and the larger size is. It was set to x. Focus tolerance: 1L1S having a line width of 0.35 μm is observed by using a scanning electron microscope, and the resolved pattern dimension is within ± 10% of the mask design dimension, and the resist pattern film before development is formed. The focus allowance was evaluated from the range of focus deviation when the ratio of the thickness of the film after development to the thickness of (1) (remaining film rate) was 90% or more. A sample equivalent to the comparative example was evaluated as Δ, a sample having a larger swing range was designated as ◯, and a sample having a smaller swing range was designated as x. -Developability: Using a scanning electron microscope, those having less scum and less development than those of Comparative Example were evaluated as ◯, those having equivalents were evaluated as Δ, and those having more scum and less development as x. -Pattern shape: The dimension L1 of the lower side and the dimension L2 of the upper side of a 1L1S rectangular section having a line width of 0.35 μm are measured using a scanning electron microscope, and 0.85 ≦ L2 / L1 ≦ 1, and When the pattern shape was vertical, it was marked as ◯. Moreover, the thing lacking these conditions was set as x.・ Heat resistance: A silicon wafer on which a resist pattern is formed is heated in an oven at 130 ° C. for 2 minutes, ○ when the pattern shape is not broken, Δ when the edge is starting to break, △ is completely broken, and the shape is broken. The ones that are marked are marked with x.

Example 6 The resins in Example 5 were changed from those in Example 1 to Example 2
The resist pattern obtained in the same manner was evaluated except that the resin synthesized in 1 was replaced. The results are shown in Table-1. Example 7 The resins in Example 5 were changed from those in Example 1 to Example 3
The resist pattern obtained in the same manner was evaluated except that the resin synthesized in 1 was replaced. The results are shown in Table-1. Example 8 The resins in Example 5 were changed from those in Example 1 to Example 4
The resist pattern obtained in the same manner was evaluated except that the resin synthesized in 1 was replaced. The results are shown in Table-1.

Example 9 The resin used in Example 5 was replaced with the novolak resin (# 1) 8.
The resist pattern obtained in the same manner was evaluated except that the mixture was 5 parts by weight and 8.5 parts by weight of the resin of Example 3. The results are shown in Table-1. In addition, (# 1) novolak resin is m-cresol / p-cresol = 7/3, cresol / formalin = 1 / 0.8, oxalic acid catalyst,
Molecular weight (Mw) obtained by reacting under reflux = 9
800 resins.

Example 10 The resin used in Example 5 was replaced with novolac resin (# 1) 12
The resist pattern obtained in the same manner was evaluated except that a mixture of 5 parts by weight of the resin of Example 4 was used.
The results are shown in Table-1. Comparative Example 1 The resin used in Example 5 was replaced with the novolak resin (# 1) 17
The resist pattern obtained in the same manner was evaluated except that the weight part was changed. The results are shown in Table-1.

[0032]

[Table 1]

[0033]

The salicylic acid aralkyl resin of the present invention is a novel resin, and the photoresist resin composition obtained by using this resin as an alkali-soluble resin has high sensitivity, high resolution and heat resistance. Also shows excellent performance.

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-8-53538 (JP, A) JP-A-6-211742 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 61/00-61/12

Claims (6)

(57) [Claims] 1. A salicylic acid-based aralkyl resin represented by the general formula (1) (formula 1). [Chemical 1] [Wherein X is a salicylic acid residue (A) or a bisphenol residue (B) represented by the following formula (2) (Chemical Formula 2)] And the A / B molar ratio is 99/1 to 50/5.
0, and m represents an integer of 0 to 100] 2. An aralkyl alcohol derivative or aralkyl halide represented by the general formula (3) (Chemical Formula 3) using methyl salicylate and a bisphenol represented by the formula (2) as a condensing agent in the presence of an acid catalyst. Chemical 3] (Wherein R ₁ represents a hydroxyl group, a lower alkoxy group having 4 or less carbon atoms, or a halogen atom), and then unreacted methyl salicylate is distilled off, and the resulting ester of the resin is treated with an alkali. The method for producing a salicylic acid-based aralkyl resin according to claim 1, which comprises hydrolyzing. 3. A photoresist composition comprising an alkali-soluble resin and a photosensitizer, wherein the salicylic acid aralkyl resin according to claim 1 is used as an essential component of the alkali-soluble resin. Resin composition for resist. 4. The photoresist resin composition according to claim 3, wherein the alkali-soluble resin contains 1% by weight to 99% by weight of a salicylic acid aralkyl resin. 5. The alkali-soluble resin is represented by salicylic acid aralkyl resin and phenol novolac, cresol novolac, phenol aralkyl resin represented by the general formula (4) or (formula 4), and general formula (5) or (formula 4). The resin composition for photoresists according to claim 4, further comprising at least one selected from a phenol-dicyclopentadiene co-condensation resin, hydroxypolystyrene or a hydride thereof. [Chemical 4] (In the above formula, R ₂ and R ₃ are each a hydrogen atom, a methyl group,
Represents a hydroxyl group or a halogen atom, n is 0 to 100, and l is 0
~ Represents an integer of 20) 6. The resin composition for photoresist according to claim 3, wherein the photosensitizer is a quinonediazide sulfonic acid ester.