JPH04301851A - Positive type resist composition - Google Patents

Abstract

PURPOSE:To enhance sensitivity, remaining film endurance, resolution, and dimension controllability by incorporating a mixture of the esters between the hydroxides of a specified phenol compound and quinonediazidosulfonic acid and between these hydroxides and sulfonic acid and/or carboxylic acids as a photosensitive agent. CONSTITUTION:An alkali-soluble phenol resin, and a mixture of the hydroxyl groups of one of the phenol compounds represented by formulae I esterified by the quinonediazido sulfonic acid and those esterified by sulfonic acid represented by formula II: -OSO2R<9> and/or esterified by carboxylic acid represented by formula III: -OCOR<10> are incorporated as the photosensitive agent. In formulae I-III, A is optionally substituted alkylene, or the like; (n) is 0 or 1; each of R<1>-R<8> is H, halogen, OH, 1-4C alkyl, or the like; and each of R<9> and R<10> is optionally substituted alkyl or the like.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a positive resist composition, and more particularly to a positive resist composition for microfabrication necessary for manufacturing semiconductor devices, magnetic bubble memory devices, integrated circuits, etc. .

0002

[Background Art] When manufacturing semiconductors, a photoresist film is created by applying resist to the surface of a silicon wafer, and a latent image is formed by irradiating it with light, which is then developed to form a negative or positive image. Semiconductor elements are formed using lithography technology. Conventionally, as a resist composition for forming a semiconductor element, a negative resist composed of cyclized polyisoprene and a bisdiazide compound is known. However, since this negative resist is developed with an organic solvent, it swells significantly and has a limited resolution.
This method has the disadvantage that it cannot be used to manufacture highly integrated semiconductors.

On the other hand, a positive resist made of an alkali-soluble novolac resin and a quinone diazide compound that undergoes alkaline development does not swell and has essentially excellent resolution, so it is widely used as semiconductors become more highly integrated. It has become possible to do so. Furthermore, improvements in the performance of positive resists and higher performance exposure mechanisms have improved resolution, making it possible to form fine patterns of 1 μm or less.

By the way, in forming fine patterns of 1 μm or less, especially 0.8 μm or less, it is necessary to control the dimensions of the resist more strictly. However, conventional positive resist compositions have not always yielded satisfactory results, and there has been a strong demand for positive resist compositions with good dimensional controllability.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a positive resist composition that has excellent balance of various properties such as sensitivity, residual film rate, and resolution. Another object of the present invention is to provide a positive resist that exhibits small dimensional changes with respect to the exposure amount, particularly in microfabrication of 1 μm or less, and has an excellent so-called exposure margin.

[0006] As a result of intensive research to overcome the problems of the prior art, the present inventors have found that in a positive resist composition containing an alkali-soluble phenolic resin and a photosensitizer, a phenolic resin is used as the photosensitizer. 4 hydroxyl groups
The above object can be achieved by incorporating a mixed esterified product in which the hydroxyl group of a specific compound having the above is converted into a quinone diazide sulfonic acid ester, and a part of the hydroxyl group is converted into a sulfonic acid ester and/or a carboxylic acid ester and capped. Based on this finding, the present invention has been completed.

[0007]

[Means for Solving the Problems] Thus, according to the present invention, an alkali-soluble phenolic resin and the following general formula [
The hydroxyl group of at least one phenol compound represented by [I] is esterified with quinonediazide sulfonic acid, and the hydroxyl group is esterified with sulfonic acid as shown in general formula [II] and/or as shown in general formula [III]. There is provided a positive resist composition characterized in that it contains a mixed esterified product which has been carboxylic acid esterified so as to be esterified as a photosensitizer.

General formula [I]

[0009]

embedded image (A: an alkylene group, a substituted alkylene group, an alkenyl group, a substituted alkenyl group, an arylene group, or a substituted arylene group. n represents 0 or 1.

R1 to R8: hydrogen, halogen, hydroxyl group, C
1-C4 alkyl group, substituted alkyl group, C2-C5 alkenyl group, substituted alkenyl group, C6-C15 aryl group, substituted aryl group, C1-C6 alkoxy group,
or C1 to C5 acyl groups, which may be the same or different. )

General formula [II] -OSO
2R9 (R9: an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group)

General formula [III] -OCOR
10 (R10: an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group) The present invention will be described in detail below.

(Alkali-soluble phenolic resin) Examples of the alkali-soluble phenolic resin used in the present invention include condensation reaction products of phenols and aldehydes, condensation reaction products of phenols and ketones, and vinylphenol-based resins. Examples include polymers, isopropenylphenol polymers, and hydrogenation reaction products of these phenol resins.

Specific examples of the phenols used here include monohydric phenols such as phenol, cresol, xylenol, ethylphenol, propylphenol, butylphenol, and phenylphenol, resorcinol, pyrocatechol, hydroquinone, bisphenol A, and phlorog. Examples include polyhydric phenols such as lucinol and pyrogallol. Specific examples of aldehydes include formaldehyde, acetaldehyde, benzaldehyde, and terephthalaldehyde. Specific examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone, and the like. These condensation reactions can be carried out according to conventional methods.

The vinylphenol polymer is selected from homopolymers of vinylphenol and copolymers of vinylphenol and copolymerizable components. Specific examples of copolymerizable components include acrylic acid, methacrylic acid, styrene, maleic anhydride, maleic imide, vinyl acetate, acrylonitrile, and derivatives thereof.

The isopropenylphenol-based polymer is selected from homopolymers of isopropenylphenol and copolymers of isopropenylphenol and copolymerizable components. Specific examples of copolymerizable components include acrylic acid, methacrylic acid, styrene, maleic anhydride, maleic imide, vinyl acetate, acrylonitrile, and derivatives thereof.

If a hydrogenation reaction product of a phenolic resin is used, the product can be produced by any known method. For example, this can be achieved by dissolving the phenolic resin in an organic solvent and introducing hydrogen in the presence of a homogeneous or heterogeneous hydrogenation catalyst. These alkali-soluble phenolic resins can be used alone, or two or more types can be used in combination.

If necessary, the positive resist composition of the present invention may contain a combination of styrene and acrylic acid, methacrylic acid, or maleic anhydride in order to improve developability, storage stability, heat resistance, etc. Polymers, copolymers of alkenes and maleic anhydride, vinyl alcohol polymers, vinyl pyrrolidone polymers, rosin, shellac, etc. can be added. The amount added is 0 to 50 parts by weight, preferably 5 to 20 parts by weight, of the above polymer per 100 parts by weight of the alkali-soluble phenolic resin.

(Photosensitizer) In the photosensitizer used in the present invention, a part of the hydroxyl group of the phenol compound represented by the above general formula [I] is converted to quinonediazide sulfonic acid ester, and a part of the hydroxyl group is converted into the above general formula [I]. Sulfonic acid esterification represented by formula [II] and/or general formula [II]
I] is a mixed esterified product capped by carboxylic acid esterification.

In the phenol compound represented by the general formula [I], the alkyl group, alkenyl group, and aryl group are
It may be substituted with halogen, hydroxyl group, alkoxy group, etc. Further, the phenol compounds may be used alone or in combination of two or more.

The phenol compound represented by the general formula [I] can be synthesized by a method such as reacting a dialdehyde compound with 4 equivalents or an excess amount of the phenol compound under an acidic catalyst. Specific compounds obtained by such a method include dialdehyde compounds such as glyoxal, glutaraldehyde, 2-hydroxyadipialdehyde, terephthalaldehyde, isophthalaldehyde, formylsalicylaldehyde, 2-hydroxy-5-methyl Using isophthalaldehyde, 2,3-naphthalenedialdehyde, etc., phenol compounds such as phenol, o,m-cresol, 2,5-xylenol, 3,5-xylenol, ethylphenol, o,m-chlorophenol, o
, m-methoxyphenol, catechol, homocatechol, resorcin, 2-methylresorcin, 5-methylresorcin, 4-ethylresorcin, 4-chlororesorcin, 4-acetylresorcin, and the like. Specific examples include the following.

[0022]

[Chemical formula 3]

[0023]

[C4]

[0024]

[C5]

[0025]

[C6]

[0026]

[C7]

[0027]

[Chemical formula 8]

[0028]

[Chemical formula 9]

[0029]

[Chemical formula 10]

[0030]

[Chemical formula 11]

[0031]

[Chemical formula 12]

[0032]

[Chemical formula 13]

[0033]

[Chemical formula 14]

[0034]

[Chemical formula 15]

[0035]

[Chemical formula 16]

[0036]

[Chemical formula 17]

[0037]

[Chemical formula 18]

[0038]

[Chemical formula 19]

[0039]

[C20]

[0040]

[C21]

[0041]

[C22]

[0042]

[C23]

The quinonediazide sulfonic acid ester moiety in the mixed ester is not particularly limited, but includes, for example, 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid Ester, 1,2-naphthoquinone diazide-5
-sulfonic acid ester, o-quinonediazide sulfonic acid ester such as 2,1-naphthoquinonediazide-4-sulfonic acid ester, 2,1-naphthoquinonediazide-5-sulfonic acid ester, and other quinonediazide sulfonic acid esters.

Quinonediazide sulfonic acid ester can be obtained by converting quinonediazide sulfonic acid into sulfonyl chloride with chlorosulfonic acid according to a conventional method, and condensing the obtained quinonediazide sulfonyl chloride with a phenol compound represented by the general formula [I]. It will be done. For example, a predetermined amount of the phenol compound represented by the general formula [I] and 1,2-naphthoquinonediazide-5-sulfonyl chloride are dissolved in a solvent such as dioxane, acetone, or tetrahydrofuran, and triethylamine, pyridine, sodium carbonate, or sodium hydrogen carbonate is dissolved. It can be prepared by adding a basic catalyst such as sodium hydroxide or potassium hydroxide to react, washing the resulting product with water, and drying. Note that the phenol compound represented by the general formula [1] has already been converted into a sulfonic acid ester represented by the general formula [II] and/or a carboxylic acid ester represented by the general formula [III], in which a part of its hydroxyl groups has already been converted into a sulfonic acid ester represented by the general formula [III]. If the capped phenol compound is reacted with quinonediazide sulfonyl chloride, it can be converted into a quinonediazide sulfonic acid ester in the same manner as described above.

A part of the hydroxyl group of the phenol compound represented by the general formula [1] is sulfonic acid esterified as shown in the above general formula [II] and/or as shown in the general formula [III]
Capping by carboxylic acid esterification as shown in can be carried out by reacting a phenol compound with a sulfonic acid halide and/or a carboxylic acid halide under a basic catalyst, similar to the method for synthesizing quinonediazide sulfonic acid ester. . Moreover, capping with a carboxylic acid ester can also be carried out by reacting a phenol compound and an acid anhydride according to a known method.

By the way, the photosensitizer used in the present invention is obtained by converting the phenol compound of the general formula [1] into (1) sulfonic acid esterification represented by the general formula [II] and/or by esterifying the phenol compound represented by the general formula [III]. (2) Capping by carboxylic acid esterification and quinonediazide sulfonic acid esterification are performed simultaneously, or (2) capping is performed first and then quinonediazide sulfonic acid esterification is performed.
Alternatively, it can be synthesized by any method such as (3) first performing quinonediazide sulfonic acid esterification and then capping.

The sulfonic acid halide or carboxylic acid halide used for the sulfonic acid esterification represented by the general formula [II] or the carboxylic acid esterification represented by the general formula [III] is not particularly limited, but specific examples thereof include: Examples include the following compounds. Examples of the sulfonic acid halide include methanesulfonic acid chloride,
Alkanesulfonic acid halides such as methanesulfonic acid fluoride, ethanesulfonic acid chloride, n-propanesulfonic acid chloride, n-butanoic acid chloride, pentanesulfonic acid chloride; chloromethylsulfonic acid chloride, dichloromethylsulfonic acid chloride, trichloromethylsulfone Substituted alkanesulfonic acid halides such as acid chloride and 2-chloroethylsulfonic acid chloride; Alkenesulfonic acid halides such as ethenesulfonic acid chloride and propenesulfonic acid chloride; benzenesulfonic acid chloride, benzenesulfonic acid fluoride, 1-naphthalenesulfone Acid chloride, arylsulfonic acid halides such as 2-naphthalenesulfonic acid chloride; p-toluenesulfonic acid chloride, p-
Ethylbenzenesulfonic acid chloride, p-xylenesulfonic acid chloride, 2,4,6-triisopropylbenzenesulfonic acid chloride, p-styrenesulfonic acid chloride, p-methoxybenzenesulfonic acid chloride, p-dimethylaminobenzenesulfonic acid chloride, p- -acetamidobenzenesulfonic acid chloride, p-
Examples include substituted arylsulfonic acid halides such as phenylazobenzenesulfonic acid chloride, m-nitrobenzenesulfonic acid chloride, p-nitrobenzenesulfonic acid chloride, p-chlorobenzenesulfonic acid chloride, and 2,4,5-trichlorobenzenesulfonic acid chloride. .

Examples of the carboxylic acid halides include alkanecarboxylic acid halides such as acetic acid chloride, acetic acid bromide, propionic acid chloride, propionic acid bromide, butyric acid chloride, isopropanecarboxylic acid chloride, valeric acid chloride, and pentanecarboxylic acid chloride; Substituted alkane carboxylic acid halides such as chloroacetic acid chloride, dichloroacetic acid chloride, and trichloroacetic acid chloride; Alkene carboxylic acid halides such as acrylic acid chloride and crotonic acid chloride; Substituted alkene carboxylic acid halides such as methacrylic acid chloride, α-ethyl acrylic acid chloride, etc. Acid halides; benzoic acid chloride, benzoic acid bromide, 1-naphthoic acid chloride,
Arylcarboxylic acid halides such as 2-naphthoic acid chloride; substituted aryls such as 4-methylbenzoic acid chloride, 4-ethylbenzoic acid chloride, 2,4-dimethylbenzoic acid chloride, and 3,4,5-trimethoxybenzoic acid chloride Examples include carboxylic acid halides; and the like.

The photosensitizer obtained by the above method is subjected to quinonediazide sulfonic acid esterification and capping (sulfonic acid esterification and/or carboxylic acid esterification).
Since this occurs randomly, it is obtained as a mixture (mixed esterified product) of various compounds with different ratios and substitution positions. Each ratio of quinonediazide sulfonic acid esterification and capping is defined as an average value of these mixtures, but in the present invention, it is expressed by the charging ratio of each raw material.

The quinonediazide sulfonic acid esterification ratio (esterification rate) is on average 5 to 99 mol%, preferably 10 to 95 mol% of the hydroxyl groups of the phenol compound represented by the general formula [I]. If the ratio of quinonediazide sulfonic acid esterification is too low, it may lead to deterioration of pattern shape and resolution, and conversely, if this ratio is too high, it may lead to deterioration of sensitivity.

The capping ratio (capping ratio) is on average in the range of 1 to 95 mol%, preferably 5 to 40 mol% of the hydroxyl groups of the phenol compound represented by the general formula [I]. When the capping ratio is less than 1 mol %, the desired effect cannot be sufficiently obtained, and on the other hand, when it exceeds 95 mol %, the sensitivity decreases significantly and development residues are likely to occur. The total of the quinonediazide sulfonic acid esterification ratio and the capping ratio varies depending on whether or not other photosensitizers are used in combination and the ratio of combination, etc., which will be described later, but usually, the sum of the hydroxyl groups of the phenol compound represented by general formula [I] Average 6 to 100 mol%, preferably 40 when no other photosensitizer is used
~95 mol%, and when used together, 10~95 mol%.

The blending ratio of the photosensitizer used in the present invention is not particularly limited, but is usually 1 to 100 parts by weight, based on 100 parts by weight of the alkali-soluble phenol resin.
Preferably it is in the range of 5 to 40 parts by weight. If the blending ratio is too low, a sufficient residual film rate cannot be obtained, leading to deterioration of resolution, and on the other hand, if the blending ratio is too high, heat resistance deteriorates, which is not preferable.

The photosensitizers used in the present invention can be used alone or in combination of two or more. It can also be used in combination with other types of photosensitizers. The other type of photosensitizer to be mixed is not particularly limited, and any known quinonediazide sulfonic acid ester can be used. Specific examples include cresol, xylenol, resorcinol, catechol, hydroquinone, pyrogallol, phloroglucinol, phloroglucide, 2,3,4-trihydroxybenzophenone, 2,
4,4-trihydroxybenzophenone, 2,3,4,
4'-tetrahydroxybenzophenone, 2,2',4
, 4'-tetrahydroxybenzophenone, 2,2',
3,4,4'-pentahydroxybenzophenone, 2,
2',3,4,5'-pentahydroxybenzophenone, 2,3,3',4,5'-pentahydroxybenzophenone, 2,3,3',4,4',5'-hexahydroxybenzopheone , 2, 3', 4, 4', 5', 6-
Hexahydroxybenzophenone, methyl gallate, ethyl gallate, propyl gallate, 2,2-bis(4-
hydroxyphenyl)propane, 2,2-bis(2,4
-dihydroxyphenyl)propane, 2,2-bis(2
, 3,4-trihydroxyphenyl)propane, cresol novolak resin, resorcinol-acetone resin, pyrogallol-acetone resin, polyvinylphenol resin, and copolymers of vinylphenol.

In particular, a quinonediazide sulfonic acid ester of a phenol compound represented by the above general formula [1] is preferably used. The ratio of other photosensitizers to be used together is
It is usually 0.05 to 20 times as much as the photosensitizer 1 of the present invention.

(Other Components) The positive resist composition of the present invention is usually used after being dissolved in a solvent in order to form a resist film by applying it to a substrate. As a solvent, ketones such as acetone, methyl ethyl ketone, cyclohexanone, and cyclopentanone; n-propyl alcohol, i
Alcohols such as so-propyl alcohol, n-butyl alcohol, and cyclohexanol; Ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and dioxane; Alcohol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; Propyl formate , butyl formate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl acetate, ethyl acetate, methyl lactate, ethyl lactate and other esters; cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, butyl cellosolve Cellosolve esters such as acetate; Propylene glycols such as propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether; diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether , diethylene glycols such as diethylene glycol diethyl ether and diethylene glycol methyl ethyl ether; halogenated hydrocarbons such as trichloroethylene; aromatic hydrocarbons such as toluene and xylene; polar solvents such as dimethylacetamide, dimethylformamide, N-methylacetamide, etc. can be mentioned. These may be used alone or in combination of two or more.

The positive resist composition of the present invention may contain compatible additives such as dyes, surfactants, storage stabilizers, sensitizers, anti-striation agents, and plasticizers, if necessary. can be done.

As the developer for the positive resist composition of the present invention, an aqueous alkali solution is used, and specifically, sodium hydroxide, potassium hydroxide, sodium silicate,
Inorganic alkalis such as ammonia; Primary amines such as ethylamine and propylamine; Secondary amines such as diethylamine and dipropylamine; Tertiary amines such as trimethylamine and triethylamine; Alcohol amines; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, and the like.

Further, if necessary, a suitable amount of a water-soluble organic solvent such as methanol, ethanol, propanol or ethylene glycol, a surfactant, a storage stabilizer, a resin dissolution inhibitor, etc. can be added to the aqueous alkali solution.

[0059]

[Examples] The present invention will be explained in more detail with reference to Examples and Comparative Examples below. In addition, parts and % in the examples
are based on weight unless otherwise specified.

[Synthesis Example 1] (Synthesis of alkali-soluble phenol resin) m-cresol/p-cresol (55/45) mixture, 37% formalin aqueous solution, and oxalic acid were each added in an amount of 0.75 mol based on the total amount of cresol. The mixture was placed in a flask equipped with a condenser tube and a stirring device at a ratio of 0.03 mol, and was maintained at 95 to 100°C to react for 1 hour. After this, the temperature was raised to 100℃ or higher, water was distilled off over 2 hours, and the temperature was further increased to 170℃ while 10 to 30m
After vacuum distillation was performed at mHg to remove unreacted monomers and water, the molten resin was returned to room temperature and collected. The weight average molecular weight of this novolak resin in terms of polystyrene is 90.
It was 00.

[Synthesis Example 2] (Synthesis of photosensitizer A) The compound of formula 5 above was used as a phenol compound, methanesulfonic acid chloride was used as a capping agent in an amount corresponding to 10 mol % of the hydroxyl groups of this phenol compound, and 1, An amount of 2-naphthoquinonediazide-5-sulfonic acid chloride corresponding to 65 mol% of the hydroxyl groups of this phenol compound was dissolved in dioxane to prepare a 10% solution. 20-25
Triethylamine was mixed with methanesulfonic acid chloride and 1,2-naphthoquinonediazide-5 while controlling the temperature at °C.
- 1.2 equivalents of the total amount of sulfonic acid chloride
The mixture was added dropwise over a period of minutes, and was maintained for an additional 4 hours to complete the reaction. The precipitated salt was separated by filtration, and 10 times the amount of the reaction solution was
．． It was poured into a 2% aqueous oxalic acid solution. The precipitated solid content was filtered, washed with ion-exchanged water, and dried to obtain photosensitizer A.

[Synthesis Example 3] (Synthesis of photosensitizers B to G) As a capping agent, p-toluenesulfonic acid chloride (
Photosensitizer B), p-methoxybenzenesulfonic acid chloride (Photosensitizer C), acetic acid chloride (Photosensitizer D), acrylic acid chloride (Photosensitizer E), benzoyl chloride (Photosensitizer F), or 3,4,5 Each photosensitizer was obtained in the same manner as in Synthesis Example 2 except that -trimethoxybenzoic acid chloride (photosensitizer G) was used.

[Synthesis Example 4] (Synthesis of photosensitizers H to M) As the phenol compound, the compound of formula 3 (photosensitizer H),
Compound of Chemical Formula 4 (Photosensitizer I), Compound of Chemical Formula 6 (Photosensitizer J)
, using the compound of chemical formula 9 (photosensitizer K), the compound of chemical formula 15 (photosensitizer L), or the compound of chemical formula 20 (photosensitizer M), and using p-toluenesulfonic acid chloride as a capping agent, the capping rate was determined. Each photosensitizer was obtained in the same manner as in Synthesis Experiment 2, except that the esterification rate was changed depending on the type of photosensitizer. The capping rate and esterification rate of each are shown in Table 1.

[Synthesis Example 5] (Synthesis of Photosensitizers N to O) Using the compound of formula 5 above as a phenol compound, without using a capping agent, 1,2 Photosensitizer N was obtained in the same manner as in Synthesis Example 2 using -naphthoquinonediazide-5-sulfonic acid chloride. Similarly, as a phenolic compound, 2,3,4
, 4'-tetrahydroxybenzophenone was used to obtain a photosensitizer O with an esterification rate of 85 mol%.

[Example 1] 100 parts of the novolak resin obtained in Synthesis Example 1 and 25 parts of photosensitizer A were mixed with 35 parts of ethyl cellosolve.
A resist solution was prepared by dissolving the resist solution in 0 parts and filtering through a 0.1 μm Teflon filter (polytetrafluoroethylene filter). After applying the above resist solution onto a silicon wafer using a coater, prebaking was performed at 100° C. for 90 seconds to form a resist film with a thickness of 1.17 μm. This wafer is transferred to a G-line stepper NSR1505G6E.
(manufactured by Nikon Corporation, NA = 0.54) and a test reticle, after performing exposure while varying the exposure time,
Post-exposure bake for 60 seconds at 10°C.
sure Baking). Then 2.38
2% tetramethylammonium hydroxide aqueous solution
A positive pattern was formed by developing at 3° C. for 1 minute using the paddle method.

This wafer was taken out and observed under an electron microscope, pattern formation and pattern dimensions were measured, and resist evaluation was performed. The results are shown in Table 1. In Table 1, "sensitivity" represents the exposure time that allows a 0.65 μm 1:1 line & space pattern to be formed according to the design dimensions, and "resolution"
is the limit resolution under this exposure condition, and the "residual film rate" is
The "exposure margin" represents the ratio of the resist film thickness before and after development, and the "exposure margin" is a graph of the relationship between the exposure time and the pattern dimension of 0.65 μm. This is the value obtained by finding the amount of variation and dividing this amount of variation by the sensitivity. Moreover, capping (%)/esterification (%) is mol%.

[Examples 2 to 13] Instead of photosensitizer A,
Resist solutions were prepared and evaluated in the same manner as in Example 1, except that each of the photosensitizers B to M was used. The results are shown in Table 1.

[Comparative Examples 1 and 2] Resist solutions were prepared and evaluated in the same manner as in Example 1, except that photosensitizers N to O were used instead of photosensitizer A, respectively. The results are shown in Table 1.

[Example 14] After applying the resist solution prepared in Example 1 onto a silicon wafer using a coater,
Prebaked at 0°C for 90 seconds, resulting in a film thickness of 1.18μm.
A resist film was formed. This wafer was transferred to an i-line stepper NSR1505i6A (manufactured by Nikon Corporation, NA=0.45).
After exposure was performed while varying the exposure time using a test reticle, post-exposure baking was performed at 110° C. for 60 seconds. Next, a positive pattern was formed by developing with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23° C. for 1 minute using the paddle method. This wafer was taken out and observed with an electron microscope, pattern formation and pattern dimensions were measured, and resist evaluation was performed. The results are shown in Table 2.

[Examples 15 to 20] Patterns were formed in the same manner as in Example 14, except that the resist solutions prepared in Examples 8 to 13 were used, and resist evaluation was performed. The results are shown in Table 2.

[Comparative Examples 3 and 4] Patterns were formed in the same manner as in Example 14, except that the resist solutions prepared in Comparative Examples 1 and 2 were used, and resist evaluation was performed. The results are shown in Table 2.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

Effects of the Invention According to the present invention, a positive resist composition having excellent sensitivity, residual film rate, resolution, and dimensional controllability can be provided. The positive resist composition of the present invention is particularly suitable for microfabrication of 1 μm or less.

Claims (2)

[Claims] Claim 1: The hydroxyl group of an alkali-soluble phenol resin and at least one phenol compound represented by the following general formula [I] is converted into a quinonediazide sulfonic acid ester, and the hydroxyl group is as represented by the general formula [II]. to sulfonic acid esterification and/or general formula [I
A positive resist composition comprising a carboxylic acid esterified mixed ester as shown in item II] as a photosensitizer. General formula [I] [Formula 1] (A: alkylene group, substituted alkylene group, alkenyl group, substituted alkenyl group, arylene group, or substituted arylene group. n represents 0 or 1. R1 to R8: hydrogen, Halogen, hydroxyl group, C1-C4 alkyl group, substituted alkyl group, C2-C5 alkenyl group, substituted alkenyl group, C6-C15 aryl group, substituted aryl group, C1-C6 alkoxy group, or C1-
They are C5 acyl groups and may be the same or different. ) General formula [II] -OSO2R9(
R9: alkyl group, substituted alkyl group, aryl group,
or a substituted aryl group. ) General formula [III] -OCOR10(R10
: Alkyl group, substituted alkyl group, aryl group, or substituted aryl group. ) 2. The mixed esterified product has the general formula [I
] An average of 5 to 99 mol % of the hydroxyl groups of at least one phenolic compound represented by the formula [II] is converted to quinonediazide sulfonic acid ester, and an average of 1 to 95 mol % of the hydroxyl groups are sulfonated as shown in the general formula [II]. The positive resist composition according to claim 1, which is a mixed esterified product obtained by acid esterification and/or carboxylic acid esterification as shown in general formula [III].