JPH11338138A - Positive type chemical amplification type photosensitive resin composition and production of resist image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a positive type chemical amplification type photosensitive resin compsn. having high sensitivity, high resolution and high heat resistance by using a novolak resin obtd. by bringing a cresol compd., a specified phenol compd. and an aldehyde into a polycondensation reaction in the presence of an acid catalyst as a resin soluble in an aq. alkali soln. SOLUTION: The photosensitive resin compsn. contains a resin (a) soluble in an aq. alkali soln., a compd. (b) which forms an acid when irradiated with active chemical rays and a compd. (c) having an acid decomposable group whose solubility to the aq. alkali soln. is increased by an acid catalyzed reaction in a side chain. The resin (a) is a novolak resin obtd. by bringing a cresol compd., a phenol compd. represented by the formula and an aldehyde into a polycondensation reaction in the presence of an acid catalyst. In the formula, R<1> is 1-4C alkyl and (n) is 0, 1 or 2. A coating of the photosensitive resin compsn. is irradiated with active chemical rays and developed to obtain the objective resist image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive chemically amplified photosensitive resin composition and a method for producing a resist image used in microfabrication of semiconductor devices and the like, and more particularly, to ultraviolet rays, far ultraviolet rays, X-rays, and electron beams. An acid is generated in the pattern latent image forming area by pattern irradiation of radiation such as, and the reaction using this acid as a catalyst changes the solubility of the irradiated part and the unirradiated part in the alkali developing solution, and the pattern appears. The present invention relates to a positive chemically amplified photosensitive resin composition and a method for producing a resist image using the same.

[0002]

2. Description of the Related Art In recent years, the miniaturization of integrated circuits has been advanced in accordance with high integration, and in 64M or 256M DRAMs, pattern formation of sub-half micron or less has been required, and resist materials having excellent resolution have been developed. Requested. Conventionally, a reduction projection exposure apparatus has been used for producing an integrated circuit. At present, a pattern having an exposure wavelength or less can be resolved by devising a photomask or the like. However, a resolving power sufficient to support 64M or 256M DRAM has not been obtained.

On the other hand, exposure using X-rays or electron beams can be expected to achieve finer pattern processing than exposure using light. The minimum dimension of the pattern depends on the beam diameter, and a high resolution can be obtained. However, even in an exposure method that can perform fine processing, the throughput of wafer processing poses a problem in terms of LSI mass production. As a method for improving the throughput, it is important to improve the sensitivity of the resist used, as well as to improve the apparatus.

As a resist material for achieving high sensitivity, for example, a composition containing a highly reactive medium in the presence of an acid catalyst and an acid precursor which generates an acid upon irradiation with actinic radiation is disclosed in US Pat. 3,779,778, JP-A-59-4
Compositions described in JP-A-5439 and JP-A-2-25850 are known. These known examples include compounds or polymers containing an acetal group as a highly reactive medium,
A compound or polymer containing a t-butyl group is disclosed. Since these media contain an acid-decomposable group, they are converted into a compound or a polymer that changes the solubility in a developer by using an acid generated by irradiation with actinic radiation as a catalyst.

However, in the conventional resist material, the so-called γ value is reduced because the difference in the dissolution rate in the developing solution between the irradiated portion and the non-irradiated portion, which is necessary for obtaining a fine pattern with good shape, is reduced. (Reduction in resolution). When an alkali-soluble resin and a component that reacts under an acid catalyst are mixed and used, they are separated into two inhomogeneous layers, or a hardly soluble layer is formed on the resist surface by micro-layer separation, and the pattern shape is deteriorated. There was a very serious problem.

[0006]

The present invention according to claims 1 and 2 is characterized in that an acid is generated in a pattern latent image forming portion by pattern-like irradiation of radiation such as ultraviolet rays, far ultraviolet rays, X-rays and electron beams. The reaction using the catalyst as a catalyst changes the solubility of the irradiated part and the unirradiated part in an alkali developing solution, and provides a high sensitivity, high resolution and high An object of the present invention is to provide a heat-resistant positive chemically amplified photosensitive resin composition. The third aspect of the present invention provides a method of manufacturing a resist image capable of producing a resist pattern having good resolution.

[0007]

According to the present invention, there are provided (a) a resin soluble in an aqueous alkali solution, (b) a compound capable of generating an acid upon irradiation with active actinic radiation, and (c) a side chain having solubility in an aqueous alkali solution by an acid-catalyzed reaction. In the composition containing a compound having an increased acid-decomposable group, the alkali-soluble resin may be a cresol compound or a compound represented by the general formula (I):

Embedded image (Wherein, R ¹ is an alkyl group having 1 to 4 carbon atoms, n is 0, 1
Or 2) is a positive-type chemically amplified photosensitive resin composition which is a novolak resin obtained by a polycondensation reaction of a phenol compound represented by the formula (2) and an aldehyde in the presence of an acid catalyst.

Further, the present invention provides a novolak resin obtained by subjecting an aqueous alkali-soluble resin to a polycondensation reaction of a cresol compound, a xylenol compound and a phenol compound represented by the general formula (I) with an aldehyde in the presence of an acid catalyst. And a positive chemically amplified photosensitive resin composition as described above. Further, the present invention relates to a method for producing a resist image, which comprises irradiating a coating film of any of the above-mentioned positive-working chemically amplified photosensitive resin compositions with active actinic radiation and then developing it.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As an aqueous alkali-soluble resin used in the present invention, a novolak resin obtained by reacting a specific phenol with an aldehyde is used. The phenols include 2 represented by the general formula (I).
To 4-nuclear phenolic compounds and o-cresol, m-
A cresol compound that is cresol or p-cresol is an essential component, and a xylenol compound such as 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol, or 3,5-xylenol is required. Used accordingly.

The 2- to 4-nuclear phenol compound represented by the general formula (I) includes:

Embedded image Etc. These 2- to 4-nuclear phenol compounds may be used alone or in combination of two or more.

The above-mentioned 2- to 4-nuclear phenol compound is
5 parts per 100 parts by weight of the cresol compound or 100 parts by weight of the total amount of the cresol compound and the xylenol compound
A range of ４０40 parts by weight is preferred. If the phenolic compound of 2 to 4 nuclei is small, sufficient resolution cannot be obtained when a resist material is used, and if it is too large, it tends to be difficult to achieve both sensitivity and resolution. In addition, the xylenol compound imparts heat resistance to the resist, but if the amount is too large, the dissolution inhibiting effect of the cresol compound is reduced. Therefore, the xylenol compound is used in the range of 0 to 50% by weight based on the total amount of the cresol compound and the xylenol compound. It is particularly preferable to use it in the range of 0 to 30% by weight.

The aldehydes include, for example, formaldehyde, paraformaldehyde and the like. The amount of the aldehyde used is preferably in the range of 0.5 to 1 mol per 1 mol of the phenol.

Examples of the acid catalyst for polycondensing phenols and aldehydes include inorganic acids such as hydrochloric acid, nitric acid and sulfuric acid;
Organic acids such as formic acid, oxalic acid and acetic acid can be mentioned. The amount of the acid catalyst used was 1 × 1 with respect to 1 mol of phenols.
The range of 0 ^-5 to 1 × 10 ^-1 mol is preferred. The reaction temperature and the reaction time of the polycondensation can be appropriately adjusted according to the reactivity of the synthesis raw materials, but usually the reaction temperature is 70 to 130.
° C and the reaction time is 1 to 12 hours. Examples of the polycondensation method include a method in which phenols, aldehydes and a catalyst are charged all at once, and a method in which phenols and aldehydes are added in the presence of a catalyst as the reaction proceeds. After the completion of the polycondensation, the temperature in the reaction system is reduced to 15 to 50 mmHg under reduced pressure, for example, to remove unreacted raw materials, condensed water, catalyst, and the like present in the reaction system.
The temperature is raised to 0 to 200 ° C. to remove unreacted raw materials, condensed water, acid catalyst, and the like existing in the reaction system, and then recover the resin.

In the present invention, the resin soluble in an aqueous alkali solution is preferably one from which low molecular weight components have been removed. As a method for reducing or removing such low molecular weight components in the alkali aqueous solution-soluble resin, a dissolution fractionation method is generally used. That is, an alkaline aqueous solution-soluble resin is dissolved in a good solvent such as acetone, ethyl cellosolve acetate, tetrahydrofuran, and methyl ethyl ketone to form a varnish, and the varnish is toluene, hexane, pentane,
Add it to a poor solvent such as xylene and separate it into a dilute phase with many low molecular weight components and a dense phase with many high molecular weight components,
Alternatively, a low molecular weight component is reduced or removed by forming a precipitated phase having a large amount of a high molecular weight component.

Further, as disclosed in JP-A-64-14229, a resin soluble in an aqueous alkali solution is pulverized and dispersed in an aromatic solvent such as toluene or xylene to extract and reduce or remove low molecular weight components. You may go. Further, in the present invention, as shown in JP-A-2-222409, when synthesizing a resin, a good solvent and a poor solvent are mixed with the resin and a normal polycondensation synthesis reaction is performed to obtain a low molecular weight resin. You may use the method of obtaining the alkali aqueous solution soluble resin with few components. By such a method, it is preferable that the low molecular weight component having a weight average molecular weight of 2,000 or less in terms of polystyrene of the aqueous alkali solution-soluble resin is in the range of 0 to 10% by weight. In the present invention, the weight-average molecular weight in terms of polystyrene is measured by gel permeation chromatography (GPC) using standard polystyrene, and is determined by an area ratio to the whole having a molecular weight of 2,000 or less.

In the present invention, various polyphenol compounds can be added and used. In particular, when low molecular weight components are removed, tetramethylammonium hydroxide is used.
Since the dissolution rate in a 38% by weight aqueous solution tends to decrease, it is preferable to add various polyphenol compounds in order to improve the dissolution rate. The polyphenol compound is not limited as long as it has 2 to 8 phenolic hydroxyl groups. Examples of these polyphenol compounds include bis (2-hydroxyphenyl) methane, 2-hydroxyphenyl- (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) )
Ethane, 2,2-bis (4-hydroxyphenyl) propane, tris (2-hydroxyphenyl) methane, tris (4-hydroxyphenyl) methane, bis (2-hydroxyphenyl)-(4-hydroxyphenyl) methane,
Bis (4-hydroxyphenyl)-(2-hydroxyphenyl) methane, 1,1,1-tris (2-hydroxyphenyl) ethane, 1,1-bis (2-hydroxyphenyl) -1- (4-hydroxyphenyl ) Ethane, 1,
1-bis (4-hydroxyphenyl) -1- (2-hydroxyphenyl) ethane, 1,1,1-tris (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1- [ 4- {1- (4-hydroxyphenyl) -1-methylethyl} phenylethane, 1,1
-Bis (2-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) -phenylmethane, bis (2-hydroxyphenyl) -phenylmethane, 4,4'-dihydroxy-3,3'-dimethyl- Biphenyl,

Embedded image Can be mentioned. These polyphenol compounds may be used alone or in combination of two or more.

The compounding amount of the polyphenol compound is 2 to 30 parts by weight with respect to (a) 100 parts by weight of the resin soluble in an aqueous alkali solution.
It is preferable that the amount be 5 parts by weight, especially 5 to 25 parts by weight. If the blending amount of the polyphenol compound is too small, it is difficult to obtain a sufficient resolution improving effect, and if the blending amount is too large, it tends to be difficult to achieve both sensitivity and resolution.

Examples of the compound (b) which generates an acid upon irradiation with actinic radiation used in the present invention include onium salts, halogen-containing compounds, quinonediazide compounds, sulfonic acid ester compounds and the like.

Examples of the onium salt include an iodonium salt, a sulfonium salt, a phosphonium salt, an ammonium salt, a diazonium salt and the like, preferably a diaryliodonium salt, a triarylsulfonium salt, a trialkylsulfonium salt (an alkyl group). The number of carbon atoms is 1 to 4), and examples of the counter anion of the onium salt include tetrafluoroboric acid, hexafluoroantimonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, and toluenesulfonic acid.

Examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound, and preferably include trichloromethyltriazine and bromoacetylbenzene.

As the quinonediazide compound, for example,
Examples thereof include a diazobenzoquinone compound and a diazonaphthoquinone compound.

Examples of the sulfonic acid ester compound include an ester of an aromatic compound having a phenolic hydroxyl group and an alkylsulfonic acid or an aromatic sulfonic acid. For example, as the aromatic compound having a phenolic hydroxyl group, Is phenol, resorcinol, pyrogallo-
Sulfonic acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butylsulfonic acid, and aromatic sulfonic acid, such as benzenesulfonic acid and naphthylsulfonic acid. Acids and the like.

The ester of an aromatic compound having a phenolic hydroxyl group with an alkylsulfonic acid can be synthesized by a usual esterification reaction. For example, an aromatic compound having a phenolic hydroxyl group can be reacted with an alkyl sulfonic acid or a chloride of an aromatic sulfonic acid under an alkaline catalyst. The synthesized product thus obtained can be purified by a recrystallization method or a reprecipitation method using an appropriate solvent.

From the viewpoint of providing sufficient sensitivity to active actinic radiation, the amount of the compound that generates an acid upon irradiation with active actinic radiation is preferably 2 parts by weight per 100 parts by weight of the aqueous alkali soluble resin.
To 30 parts by weight, preferably 5 to 15 parts by weight.
It is preferably in parts by weight. If the amount of the compound that generates an acid by active actinic radiation is too large, the solubility in a solvent is reduced. If the amount is too small, sufficient sensitivity cannot be obtained.

The compound (c) having an acid-decomposable group whose solubility in an aqueous alkali solution is increased by an acid-catalyzed reaction in the side chain used in the present invention is such that the acid-decomposable group of the side chain is efficiently dissociated by an acid. The solubility of the final product in an aqueous alkaline solution is significantly different from that of the compound before dissociation. As the component (c), a hydrogen atom such as a phenolic hydroxyl group or a carboxyl group of an alkali aqueous solution-soluble resin such as an acrylic acid resin, a copolymer of styrene and acrylic acid, or a polymer of hydroxystyrene (including polyvinyl phenol) is used. Is substituted by a group capable of dissociating in the presence of an acid (acid-decomposable group). It is not necessary that all of the hydroxyl groups or carboxyl groups of the vinyl polymer having an acid-decomposable group be protected by the acid-decomposable group. Regarding the molecular weight of the vinyl polymer having an acid-decomposable group, the weight-average molecular weight (Mw) [weight-average molecular weight measured by gel permeation chromatography using a standard polystyrene calibration curve, the same applies hereinafter] is 1,500.
~ 3,000 are preferred. A polymer having a molecular weight in this range has good compatibility with a resin soluble in an aqueous alkali solution.

Specific examples of groups that can be dissociated in the presence of an acid include methoxymethyl, methoxyethoxymethyl, tetrahydropyranyl, tetrahydrofuranyl, benzyloxymethyl, 1-methoxyethyl, 1-ethoxyethyl group, methoxybenzyl group, t-
Butyl group, methoxycarbonyl group, ethoxycarbonyl group, t-butoxycarbonyl group, trimethylsilyl group,
Examples thereof include a triethylsilyl group and a phenyldimethylsilyl group. Among them, a tetrahydropyranyl group, a tetrahydrofuranyl group, a t-butoxycarbonyl group, a 1-ethoxyethyl group, a triethylsilyl group and the like are preferable.

The rate of substitution of hydrogen of a phenolic hydroxyl group or a carboxyl group by a group capable of dissociating in the presence of an acid (an acid-decomposable group) (that is, hydrogen of a phenolic hydroxyl group or a carboxyl group in the entire component (c)) And the ratio of the acid-decomposable group to the total number of acid-decomposable groups) is preferably from 15 to 100%, and more preferably from 30 to 100%.

The compound having an acid-decomposable group whose solubility in an aqueous alkali solution is increased by an acid-catalyzed reaction as a component (c) used in the present invention is a phenol of a compound having a phenolic hydroxyl group or a carboxyl group. It can be produced by replacing a hydrogen atom of a hydroxyl group or a carboxyl group with the acid-decomposable group. As this method, a conventionally well-known method can be adopted. For example, when an acetal group such as a tetrahydropyranyl group or a 1-ethoxyethyl group is introduced as an acid-decomposable group, 3,4,4 is used as a reactant in the presence of an acid catalyst.
A vinyl ether compound such as -dihydro-2H-pyran, ethyl vinyl ether or the like is reacted in a suitable reaction solvent.

(C) The compound having an acid-decomposable group whose solubility in an aqueous alkali solution is increased by an acid-catalyzed reaction is used in an amount of 3 to 300 parts by weight based on 100 parts by weight of the (a) aqueous alkali-soluble resin. Preferably, it is more preferably 5 to 200 parts by weight. If the amount of the compound having an acid-decomposable group increases the solubility in an alkaline aqueous solution due to an acid catalyzed reaction, the irradiated portion may be developed in a system in which the solubility in an alkaline aqueous solution increases due to an acid catalyzed reaction. If the amount of the compound having an acid-decomposable group whose solubility in an aqueous alkali solution is increased by an acid-catalyzed reaction is too small, the irradiated portion may become alkaline due to the acid-catalyzed reaction. In a system in which the solubility in an aqueous solution increases, the film loss in the unirradiated portion tends to increase.

Examples of the solvent used in the present invention include glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol alkyl ether acetates such as methyl cellosolve acetate, diethylene glycols such as diethylene glycol monomethyl ether, and propylene glycol methyl ether acetate. Propylene glycol alkyl ether acetates, aromatic hydrocarbons such as toluene, ketones such as cyclohexanone, and esters such as 2-hydroxypropionic acid. The amount of the solvent used is preferably from 50 to 95% by weight, more preferably from 60 to 90% by weight, based on the total amount of the photosensitive resin composition containing the solvent. If the amount of the solvent is too small, the solvent is not sufficiently soluble in the resist material. If the amount of the solvent is too large, a sufficient film thickness cannot be obtained when the resist film is used.

The photosensitive resin composition of the present invention has coatability,
For example, in order to prevent striation (unevenness in film thickness) and improve developability, a surfactant can be added. As surfactants, for example, polyoxyethylene uraryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenol ether, and as commercial products, Megafax F171, F173 (Dai Nippon Ink Chemical Industry (Trade name), Florard FC430,
FC431 (trade name, manufactured by Sumitomo 3M Limited), and organosiloxane polymer KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.). Further, the photosensitive resin composition of the present invention may optionally contain a storage stabilizer, a dissolution inhibitor, and the like.

With the photosensitive resin composition of the present invention, a resist film is formed on a substrate such as a wafer or glass, and a resist image is produced by irradiation with active actinic radiation and development. As the method, a conventionally well-known method can be adopted. There are no particular restrictions on the conditions of irradiation with actinic radiation and development. For example, radiation such as far ultraviolet rays such as excimer lasers, X-rays such as synchrotron radiation, and charged particle beams such as electron beams are used.

Examples of the developer for the photosensitive resin composition of the present invention include inorganic alkalis such as sodium hydroxide, primary amines such as ethylamine, secondary amines such as diethylamine, and secondary amines such as triethylamine. Tertiary amines,
Alkaline aqueous solutions in which alcohol amines such as dimethylethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide and choline, or cyclic amines such as piperidine are used are used.

[0034]

In general, in a positive photosensitive resin composition, increasing the dissolution rate between the irradiated part and the unirradiated part in the developing solution leads to higher resolution. The alkali aqueous solution-soluble resin used in the present invention has an effect of sufficiently lowering the dissolution rate of the unirradiated portion in the developing solution, whereby high resolution of the positive-type chemically amplified photosensitive resin composition can be achieved. .

(A) Alkali aqueous solution soluble resin (C)
In order to inhibit the dissolution in an alkali aqueous solution caused by blending a compound having an acid-decomposable group whose solubility in an aqueous alkali solution is increased by an acid-catalyzed reaction in a side chain, 100 parts by weight of the component (a) is used. The ratio of the dissolution rate of the component (a) to a 2.38% by weight aqueous solution of tetramethylammonium hydroxide when 5 parts by weight of the component (c) was blended was measured. The larger the numerical value of the parameter representing the dissolution inhibiting effect is, the greater the dissolution inhibiting effect is, and high resolution of a positive chemically amplified photosensitive resin composition using the same is expected. This value was 4 to 10 in a normal alkaline aqueous solution-soluble resin, but this value can be increased to 30 to 100 by using the alkaline aqueous solution-soluble resin of the present invention. As a result, a high-resolution chemically amplified photosensitive resin composition having a high resolution was obtained.

[0036]

The present invention will be described below with reference to examples. In the following, the dissolution inhibiting effect was evaluated by the following method. Method for evaluating dissolution inhibiting effect 5 g of an aqueous alkali solution-soluble resin was added to methyl amyl ketone 1
After dissolving in 5 g, a solution filtered through a membrane filter having a pore size of 0.2 μm is spin-coated to have a thickness of 1 μm after heat treatment.
And heat-treated at 130 ° C., placed in a 2.38 wt% aqueous solution of tetramethylammonium hydroxide, measured the time until the coating was completely dissolved, and dissolved per second The film thickness (mm / sec) was calculated. This dissolution rate is referred to as dissolution rate (a). Further, 5 g of the same alkaline aqueous solution-soluble resin and poly (p-vinylphenol) in which 95% hydrogen of the phenolic hydroxyl group of poly (p-vinylphenol) having a weight average molecular weight of about 3500 is substituted with 95% tetrahydropyranyl group.
After dissolving 0.25 g in 15 g of methyl amyl ketone, the dissolution rate is determined in the same manner as above, and this is defined as the dissolution rate (b). The ratio of the dissolution rate (a) to the dissolution rate (b) was determined, and this was defined as the dissolution inhibiting effect.

Synthesis Example 1 In a separable flask equipped with a stirrer, a condenser and a thermometer, 244 g of m-cresol and 365 of p-cresol were placed.
g, 120 g of 2,6-bis [(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol, 37
361 g of weight% formalin and 2.2 g of oxalic acid were charged,
The separable flask was immersed in an oil bath, and polycondensation was performed for 3 hours with stirring while maintaining the internal temperature at 97 ° C. Then, the internal temperature is reduced to 1
Up to 80 ° C., and simultaneously increase the pressure in the reaction vessel to 10-20.
The pressure was reduced to mmHg, and unreacted cresol, formaldehyde, water and oxalic acid were recovered. Next, the molten resin was poured into a metal vat to collect a cresol novolak resin. This resin is referred to as resin 1. The dissolution inhibiting effect of Resin 1 was 42.

Synthesis Example 2 252 g of m-cresol and 189 of p-cresol were placed in a separable flask equipped with a stirrer, a condenser and a thermometer.
g, 3,5-xylenol 189 g, 2,6-bis [(2-hydroxy-5-methylphenyl) methyl]-
100 g of 4-methylphenol, 340 g of 37% by weight formalin and 2.2 g of oxalic acid were charged, the separable flask was immersed in an oil bath, and polycondensation was performed for 3 hours while stirring at an internal temperature of 97 ° C. Then, raise the internal temperature to 180 ° C,
At the same time, the pressure in the reaction vessel was reduced to 10-20 mmHg,
Unreacted cresol, formaldehyde, water and oxalic acid were recovered. Next, the molten resin was poured into a metal vat to collect a cresol novolak resin. This resin is referred to as resin 2. The dissolution inhibiting effect of Resin 2 was 45.

Synthesis Example 3 A separable flask equipped with a stirrer was charged with 20 g of poly (p-vinylphenol) (Linker M, trade name of Maruzen Petrochemical Co., Ltd.) and 300 ml of ethyl acetate, and the mixture was stirred at room temperature (25%).
℃) to dissolve. Then, in the flask,
-Dihydro-2H-pyran (105 g) was charged at room temperature (2.
(5 ° C.) for 1 hour, and then left at room temperature for 3 days.
Next, 160 ml of a 2.38% by weight aqueous solution of tetramethylammonium hydroxide was added to the reaction solution, and the mixture was stirred well, and the organic layer was taken out. The obtained organic layer solution was washed three times with 300 ml of distilled water, and then the organic layer was dried and concentrated by an evaporator. Reprecipitation was carried out using 50 ml of petroleum ether for 50 ml of the concentrated solution. After repeating the reprecipitation operation twice, the product was dried under reduced pressure (3 mmH
g (40 ° C.) for 8 hours to obtain 22 g of poly (P-vinylphenol) in which 95% of the hydrogen of the phenolic hydroxyl group of poly (P-vinylphenol) was substituted with a tetrahydropyranyl group.

Synthesis Example 4 30 g of pyrogallol, 3.9 g of 4-dimethylaminopyridine and 300 ml of tetrahydrofuran were charged into a separable flask equipped with a stirrer, a thermometer and a dropping funnel, and dissolved by stirring at room temperature (25 ° C.). . Next, the flask was immersed in an ice bath to adjust the temperature in the reaction system to 5 ° C., and then 15 g of ethanesulfonyl chloride was added dropwise over 20 minutes using a dropping funnel. Next, 95 g of triethylamine was added dropwise over 40 minutes using a dropping funnel, and the mixture was stirred for 6 hours while keeping the temperature in the reaction system at 5 ° C. Next, the reaction solution was poured into 2000 ml of distilled water, and the deposited precipitate was separated by filtration. This precipitation was repeated several times using acetone and ethanol to obtain 32 g of pyrogallol ethanesulfonic acid ester.

Example 1 In a separable flask equipped with a stirrer, 80 g of the resin 1 obtained in Synthesis Example 1 and a polyphenol in which 95% of the phenolic hydroxyl groups obtained in Synthesis Example 3 were substituted with tetrahydropyranyl groups were used. 10 g of (p-vinylphenol), 4 g of ethanesulfonic acid ester of pyrogallol obtained in Synthesis Example 4 and 300 g of methyl amyl ketone were charged and dissolved, and after visually confirming that a uniform solution was obtained, the pore diameter was 0.1 μm. Was filtered through a membrane filter of No. 1 to prepare a Boji type chemically amplified resist solution (positive type chemically amplified photosensitive resin composition). The obtained positive chemically amplified resist solution was applied on a silicon wafer, and heat-treated at 130 ° C. for 10 minutes. 7 μm
Was obtained. After drawing a line / space pattern on the resist coating film with an irradiation dose of 1.5 μC / cm ² using an electron beam lithography system with an acceleration voltage of 50 kV,
Heat treatment at 10 ° C. for 10 minutes promoted a reaction to increase the solubility of the latent image portion of the resist coating in an aqueous alkaline solution. After this heat treatment, the resist film on which the latent image was formed was developed for 70 seconds using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide to obtain a positive resist pattern. Observation of the resist pattern by an electron microscope revealed that a 0.2 μm hole pattern was resolved, and the resist pattern was rectangular and good. The amount of film reduction after development was 0.02 μm, which was good.

Example 2 A positive chemically amplified resist solution (positive chemically amplified photosensitive resin composition) was prepared in the same manner as in Example 1 except that resin 2 was used instead of resin 1. Was prepared, and an electron beam drawing experiment was performed at an irradiation dose of 2.0 μC / cm ² . Observation of the resist pattern by an electron microscope revealed that a 0.2 μm hole pattern was resolved, and the resist pattern was rectangular and good. The amount of film reduction after development was 0.02 μm, which was good.

Comparative Example 1 A positive type chemically amplified resist solution was prepared in the same manner as in Example 1 except that cresol novolak resin CN-19 (manufactured by Meiwa Kasei Co., Ltd.) was used instead of Resin 1. (Positive-type chemically amplified photosensitive resin composition),
An electron beam lithography experiment was performed at an irradiation dose of 2.0 μC / cm ² . Observation of the resist pattern with an electron microscope revealed that the resist pattern was
Although the hole pattern of 35 μm was resolved,
The m hole pattern was not resolved. The film loss after development was 0.02 μm, which was good.
The resist pattern had an inverted tapered shape and was not good. The dissolution inhibiting effect of the cresol novolak resin CN-19 was 5.

[0044]

The positive chemically amplified photosensitive resin composition according to claim 1 or 2 has excellent sensitivity and resolution to active actinic rays such as ultraviolet rays, far ultraviolet rays, X-rays and electron beams. I have. According to the method for producing a resist image according to the third aspect, a resist pattern having excellent sensitivity and resolution can be produced.

Claims (3)

[Claims] (1) an aqueous alkali-soluble resin,
(B) a compound which generates an acid by irradiation with actinic radiation and (c) a compound having an acid-decomposable group whose solubility in an aqueous alkali solution is increased by an acid-catalyzed reaction in a side chain, wherein the aqueous alkali solution is used. The soluble resin comprises a cresol compound and a compound represented by the general formula (I): (Wherein, R ¹ is an alkyl group having 1 to 4 carbon atoms, n is 0, 1
Or 2) is a novolak resin obtained by a polycondensation reaction of a phenol compound represented by the formula (1) and an aldehyde in the presence of an acid catalyst. 2. A novolak resin obtained by a polycondensation reaction of a cresol compound, a xylenol compound and a phenol compound represented by the general formula (I) with an aldehyde in the presence of an acid catalyst. 2. The positive-working chemically amplified photosensitive resin composition according to item 1. 3. A method for producing a resist image, comprising irradiating a coating film of the positive-type chemically amplified photosensitive resin composition according to claim 1 with an actinic ray, and then developing the coating film. .