JP2775833B2 - Radiation-sensitive resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a radiation-sensitive resin composition, and more specifically, an ultraviolet ray, a far infrared ray, an X-ray, an electron beam, a molecular beam, a gamma ray, a synchrotron radiation, a proton. The present invention relates to a radiation-sensitive resin composition suitable as a positive resist for producing a highly integrated circuit responsive to radiation such as a beam.

[Prior Art] Positive resists are often used in the manufacture of integrated circuits because a high-resolution resist pattern can be obtained.

However, in recent years, the integration density of integrated circuits has been increased, and a positive resist capable of forming a resist pattern with improved resolution has been desired. For example, when a fine resist pattern is formed using a positive resist, when a latent image formed by exposure is developed with a developing solution composed of an alkaline aqueous solution, the exposed portion is quickly brought into contact with the wafer (the bottom of the pattern). Need to be developed. In the case of the conventional positive resist, when the interval between the resist patterns to be formed is 1 μm or less, there is a problem that the developability of the foot portion of the resist pattern is poor and the resolution is reduced.

Also, with the improvement in the degree of integration of integrated circuits, the wafer etching method has shifted from conventional wet etching with large side etching to dry etching with small side etching. In this dry etching, it is necessary that the resist pattern does not change at the time of etching, so that it is necessary to have good heat resistance. Dry etching is performed by an anisotropic etching method typified by reactive ion etching, and the shape of a resist pattern is directly reflected on the shape of a layer to be etched. Therefore, if the shape of the resist pattern is bad, it will be etched to the part that does not need to be etched, the dimensional accuracy will decrease,
This causes a failure of the integrated circuit or a decrease in yield. Conventional resists are insufficient in this respect, and resists having a good pattern shape are strongly desired.

[Problems to be solved by the invention]

An object of the present invention is to solve the above-mentioned problems of the prior art, to obtain a high-sensitivity, excellent developability, a good pattern shape after development and a high resolution, and to obtain a positive resist excellent in heat resistance. To provide a radiation-sensitive resin composition that can be used.

[Means for solving the problem]

The present invention provides a radiation-sensitive resin composition containing an alkali-soluble novolak resin and a 1,2-quinonediazide compound, wherein the alkali-soluble novolak resin is m-cresol, 2,5-xylenol and 2,3,5-trimethyl. It is a resin obtained by co-condensing phenol with aldehydes.

The alkali-soluble novolak resin (hereinafter, simply referred to as “novolak resin”) in the present invention includes phenols such as m-cresol, 2,5-xylenol and 2,3,5
-Obtained by condensing trimethylphenol with aldehydes in the presence of an acidic catalyst, wherein the phenols are other phenols (hereinafter referred to as "other phenols")
For example, p-cresol, o-cresol, 2,
Condensation can also be carried out using 3-xylenol, 3,4-xylenol, 3,5-xylenol, 3,4,5-trimethylphenol or the like in combination.

Although the use ratio of the phenols is not particularly limited,
Preferably m-cresol / 2,5-xylenol / 2,3,5-
Trimethylphenol / other phenols = 20-80 / 10-70 /
10-70 / 0-30 (mol%), more preferably 30-70
/ 10 to 50/10 to 50/0 to 20 (mol%).

If the proportion of m-cresol is less than 20 mol%, the sensitivity and developability of the composition may be deteriorated, and if it exceeds 80 mol%, the resolution and heat resistance of the composition may be deteriorated. If the proportion of 2,5-xylenol is less than 10 mol%, the pattern shape after development of the composition may be deteriorated, and if it exceeds 70 mol%, the sensitivity of the composition may be deteriorated. If the use ratio of 2,3,5-trimethylphenol is less than 10 mol%, the heat resistance of the composition and the current pattern after development may be deteriorated, and if it exceeds 70 mol%, the sensitivity and developability of the composition may be deteriorated. May worsen.
When the use ratio of other phenols exceeds 30 mol%,
The sensitivity, developability, and pattern shape after development of the composition may be deteriorated.

Examples of the aldehydes include formaldehyde, paraformaldehyde, benzaldehyde, acetaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde,
o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde, o-methylbenzaldehyde, m-
Examples thereof include methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde, and furfural. Of these, formaldehyde is particularly preferred. These aldehydes can be used alone or in combination of two or more.

The amount of the aldehyde used is preferably 0.7 to 3 mol, more preferably 0.8 to 1. mol, per 1 mol of the total amount of the phenol.
5 moles.

For the condensation, an acid catalyst is usually used, and examples of the acidic catalyst include inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, and formic acid, oxalic acid, and organic acids such as acetic acid. , 1 × 10 ^{-5 to} 5 × 10
^-1 mole.

In the condensation, water is generally used as a reaction medium.However, when the phenol used does not dissolve in the aqueous solution of the aldehyde and becomes a heterogeneous system from the beginning of the reaction, a hydrophilic solvent is used as the reaction medium. Can also be used. These hydrophilic solvents include, for example, methanol,
Examples include alcohols such as ethanol, propanol and butanol, and cyclic ethers such as tetrahydrofuran and dioxane. The amount of these reaction media used is
Usually, it is 20 to 1000 parts by weight per 100 parts by weight of the reaction raw material.

The reaction temperature of the condensation can be appropriately adjusted according to the reactivity of the reaction raw materials, but is usually 10 to 200 ° C., preferably 7 to 200 ° C.
0-130 ° C.

Examples of the condensation method include a method in which phenols, aldehydes, and an acidic catalyst are charged at once, and a method in which phenols, aldehydes, and the like are added as the reaction proceeds in the presence of an acidic catalyst. .

After the completion of the condensation reaction, the internal temperature is generally raised to remove unreacted raw materials, acidic catalyst, reaction medium, and the like present in the system.
The temperature is raised to 130 to 230 ° C., and volatile components are distilled off under reduced pressure, for example, at about 20 to 50 mmHg, and the novolak resin is recovered. After the completion of the condensation reaction, the reaction mixture is dissolved in the hydrophilic solvent,
By adding a precipitant such as water, n-hexane, or n-heptane, a novolak resin can be precipitated and recovered.

The polystyrene-equivalent weight average molecular weight (hereinafter, referred to as “▲ ▼”) of the novolak resin used in the present invention is:
Preferably it is 2,000 to 15,000. When ▼ is less than 2,000, the heat resistance of the composition may be deteriorated, and when it exceeds 15,000, the sensitivity of the composition may be reduced.

The novolak resin of the present invention has a polystyrene equivalent molecular weight of 6,300 to 25,000, 2,500 to 6,000 and 150 to
When the maximum height values of the peaks in the range of 900 are a, b and c, respectively, a / b = 0 to 1.5 and c / b =
It is preferably 0.2 to 2, more preferably a / b = 0.
2 to 1.3 and c / b = 0.4 to 1.5. If the value of a / b exceeds 1.5, the developability and sensitivity of the composition may deteriorate, and if the value of c / b exceeds 2, the heat resistance and developability of the composition may deteriorate, If the value of c / b is less than 0.2, the sensitivity and developability of the composition may be deteriorated.

Examples of the 1,2-quinonediazide compound used in the present invention include, for example, 1,2-benzquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, and 1,2-naphthoquinonediazide-5. And sulfonic acid esters. Specifically, 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester of (poly) hydroxybenzene such as p-cresol, resorcinol, pyrogallol, phloroglucinol or 1 2,2-naphthoquinonediazide-5-sulfonic acid ester; 2,4-dihydroxyphenyl-propyl ketone, 2,4-dihydroxyphenyl-n-hexyl ketone, 2,4-dihydroxybenzophenone, 2,3,4-trihydroxyphenyl −
n-hexyl ketone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,
4,4'-tetrahydroxybenzophenone, 2,3,4,3'-
Tetrahydroxybenzophenone, 4'-methyl-2,3,
4,2'-tetrahydroxybenzophenone, 2,3,4,4'-
Tetrahydroxy-3'-methoxybenzophenone, 2,
2 ', 4,4'-tetrahydroxybenzophenone, 2,2'3,
4,6'-pentahydroxybenzophenone, 2,3,3 ', 4,
4 ', 5'-hexahydroxybenzophenone, 2,3', 4,
(Poly) hydroxyphenyl alkyl ketone such as 4 ', 5', 6-hexahydroxybenzophenone or (poly)
1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester of hydroxyphenylarylketone; bis (p-hydroxyphenyl ) Methane, bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2,2-bis (p-hydroxyphenyl) propane, 2,2-bis (2,4 1,2-benzoquinodiazide-4-sulfonic acid ester of bis [(poly) hydroxyphenyl] alkane such as -dihydroxyphenyl) propane, 2,2-bis (2,3,4-trihydroxyphenyl) propane, 1,2-naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5
-Sulfonic acid esters; lauryl 3,5-dihydroxybenzoate, phenyl 2,3,4-trihydroxybenzoate, 3,4,5
-Alkyl (poly) hydroxybenzoate or aryl (poly) hydroxybenzoate such as lauryl trihydroxybenzoate, propyl 3,4,5-trihydroxybenzoate, phenyl 3,4,5-trihydroxybenzoate, etc. 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester; bis (2,5-dihydroxybenzoyl) methane, Bis (2,3,4-trihydroxybenzoyl) methane, bis (2,4,6-trihydroxybenzoyl) methane, p-bis (2,5-dihydroxybenzoyl) benzene, p-bis (2,3,4 Bis [(poly) hydroxy such as -trihydroxybenzoyl) benzene and p-bis (2,4,6-trihydroxybenzoyl) benzene Nzoiru] alkanes or bis [(poly) hydroxybenzoyl] benzene 1,2-benzoquinone diazide -4
-Sulfonic acid ester, 1,2-naphthoquinone diamide-
4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester; ethylene glycol-
Di (3,5-dihydroxybenzoate), polyethylene glycol-di (3,5-dihydroxybenzoate),
1,2-benzoquinonediazide-4-sulfonic acid ester of (poly) ethylene glycol-di [(poly) hydroxybenzoate] such as polyethylene glycol-di (3,4,5-trihydroxybenzoate), 1,2-naphtho Quinonediazide-4-sulfonic acid ester or 1,2-
Naphthoquinonediazide-5-sulfonic acid ester can be mentioned. In addition to these compounds, "L
ight-Sensitive Systems "339-352, (1965), John wi
“Photores” by ley & Sons (New York) and WSDe Forest
1,2-quinonediazide compounds described in ist "50, (1975), McGraw-Hill, Inc. (New York) can also be used.

Among the 1,2-quinonediazide compounds, polyhydroxybenzophenone-1,2-quinonediazidesulfonic acid ester represented by the following general formula is particularly preferable.

(Wherein, R is an alkyl group having 1 to 3 carbon atoms, an alkoxy group or a hydrogen atom, n and m are respectively 0 ≦ n ≦ 5 and 0 ≦ m ≦ 5, and have a relationship of 3 ≦ n + m ≦ 6, D represents a hydrogen atom, a 1,2-naphthoquinonediazide-4-sulfonyl group or a 1,2-naphthoquinonediazide-5-sulfonyl group, and at least one of a plurality of Ds is 1,2-naphthoquinonediazide-4-sulfonyl Or 1,2-naphthoquinonediazido-5-sulfonyl group) Specifically, 2,3,4-trihydroxybenzophenone-
1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4-trihydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,6-
Trihydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,4,6-trihydroxybenzophenone-1,2-naphthoquinonediazide-5
1,2-naphthoquinonediazidosulfonic acid esters of trihydroxybenzophenone, such as sulfonic acid esters; 2,
2 ', 4,4'-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,2',
4,4'-tetrahydroxybenzophenone-1,2-naphthoquinodiazide-5-sulfonic acid ester, 2,3,4,3'-
Tetrahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,3'-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,4 '-Tetrahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,4'-tetrahydroxybenzophenone-1,2-naphthoxynonediazide-
5-sulfonic acid ester, 2,3,4,2'-tetrahydroxy-4'-methylbenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,2'-tetrahydroxy-4 '-Methylbenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,
4'-tetrahydroxy-3'-methoxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,4'-tetrahydroxy-3'-methoxybenzophenone-1,2-naphthoquinonediazide- 1,2-naphthoquinonediazidosulfonic acid ester of tetrahydroxybenzophenone such as 5-sulfonic acid ester; 2 ′,
3,4,5,6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2 ',
3,4,5,6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2 ',
3,4,4 ', 5-pentahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2',
3,4,4 ', 5-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2',
3,3 ', 4,5-pentahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2',
3,3 ', 4,5-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 3,3',
4,4 ', 5-pentahydroxybezophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 3,3', 4,
4 ', 5-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2', 3,4,
5,5'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2 ', 3,4,
1,2-naphthoquinonediazidesulfonic acid ester of pentahydroxybenzophenone such as 5,5'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester; 2,3,3 ', 4,4', 5 '-Hexahydroxybenzophenone-1,2-naphthoquinonediazide-4
-Sulfonic acid ester, 2,3,3 ', 4,4', 5'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3 ', 4,4', 5 ', 6-hexahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3 ′, 4,4 ′, 5 ′, 6-
Hexahydroxybenzophenone-1,2-naphthoquinonediazide sulfonic acid esters such as hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester.

The number (condensation ratio) of 1,2-naphthoquinonediazidosulfonic acid groups bonded to polyhydroxybenzophenones is 1.5 to an average for trihydroxybenzophenone-1,2-naphthoquinonediazidesulfonic acid ester.
3, in the case of tetrahydroxybenzophenone-1,2-naphthoquinonediazidosulfonic acid ester, an average of 2 to 4,
In the case of pentahydroxybenzophenone-1,2-naphthoquinonediazidosulfonic acid ester, the average is preferably 2.5 to 5, and in the case of hexahydroxybenzophenone-1,2-naphthoquinonediazidosulfonic acid ester, the average is preferably 3 to 6.

The 1,2-quinonediazide compounds can be used alone or as a mixture of two or more.

The compounding amount of the 1,2-quinonediazide compound in the composition of the present invention is usually 3 to 100 parts by weight, preferably 5 to 50 parts by weight based on 100 parts by weight of the novolak resin.

A sensitizer may be added to the composition of the present invention in order to improve the sensitivity to radiation. As these sensitizers, for example, 2H-pyrido [3,2-b] -1,4-oxazine-3 [4H] ones, 10H-pyrido [3,2-b] [1,
4] -Benzothiazines, urazoles, hydantoins, barbituric acids, glycine anhydrides, 1-hydroxybenzotriazoles, alloxanes, maleimides and the like. The amount of these sensitizers is 1,2-
It is usually 100 parts by weight or less based on 100 parts by weight of the quinonediazide compound.

Further, the composition of the present invention may contain a surfactant for improving coatability, for example, developability of a radiation-irradiated portion after formation of a striation or a dried coating film. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, and the like. Nonionic surfactants, F-Top EF301, EF303, EF352 (manufactured by Shin-Akita Kasei), Megafac F171, F172, F173 (manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M), Asahi Guard AG710 , Surflon S-382,
Fluorinated surfactants such as SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), acrylic acid or methacrylic acid (co) polymer polyflow No. .75, No.95
(Manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and the like. The amount of these surfactants is usually per solid content of the composition,
Not more than 2% by weight.

Further, in the composition of the present invention, a latent image in a radiation-irradiated portion is visualized, and a dye or a pigment for reducing the influence of halation upon radiation irradiation, and an adhesion aid for improving adhesion are compounded. Can also. In addition, the composition of the present invention may contain, if necessary, storage stability, an antifoaming agent, and the like.

As a method of applying the composition of the present invention to a substrate such as a silicon wafer, a predetermined amount of the novolak resin, the 1,2-quinonediazide compound and various compounding agents is adjusted so that, for example, the solid content concentration becomes 20 to 40% by weight. And then, for example, filtering the solution with a filter having a pore size of about 0.2 μm, and applying the solution by spin coating, flow coating, roll coating, or the like. As the solvent used at this time, for example, ethylene glycol monomethyl ether, glycol ethers such as ethylene glycol monoethyl ether, methyl cellosolve acetate, ethylene glycol alkyl ether acetates such as ethyl cellosolve acetate, diethylene glycol monomethyl ether,
Diethylene glycols such as diethylene glycol monoethyl ether; propylene glycol methyl ether acetate; propylene glycol alkyl ether acetates such as propylene glycol ethyl ether acetate; propylene glycol propyl ether acetate; aromatic hydrocarbons such as toluene and xylene; methyl ethyl ketone; cyclohexanone; Ketones, 2
-Methyl hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl oxyacetate,
Methyl 2-hydroxy-3-methylbutanoate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-
Esters such as methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate and butyl acetate can be used. These solvents may be used alone or in combination of two or more. Furthermore, N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethyl ether,
Dihexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,
Acetonylacetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone,
High boiling solvents such as ethylene carbonate, propylene carbonate and phenyl cellosolve acetate can also be added.

Examples of the developer of the composition of the present invention include, for example, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; and primary amines such as ethylamine and n-propylamine. , Secondary amines such as diethylamine and di-n-propylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethyl Quaternary ammonium salts such as ammonium hydroxide and choline or pyrrole, piperidine, 1,8-diazabicyclo (5,4,0) -7-undencene, 1,5-diazabicyclo (4,3,0) -5-nonane Alkaline aqueous solution obtained by dissolving cyclic amines such as You. The developer also includes
A suitable amount of an aqueous organic solvent, for example, an alcohol such as methanol or ethanol, or a surfactant may be added.

When the composition of the present invention is used as a positive resist, the composition of the present invention is coated on a silicon wafer, prebaked and exposed, and then heated at 70 to 140 ° C. The effect of the present invention can be further improved by performing development later.

〔Example〕

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

Incidentally, ▲ ▼ is in the examples, Toyo Soda Co. GPC column (G2000H ₆ 2 present, G3000H ₆ 1 present, G4000H ₆ 1 present) using a flow rate of 1.5 ml / min, eluent tetrahydrofuran, column temperature: 40 ° C. Under the analysis conditions, measurement was performed by gel permeation chromatography using monodisperse polystyrene as a standard, and various properties of the resist were evaluated by the following methods.

Sensitivity: The exposure time is changed with a Nikon-NSR1505G4D reduction projection exposure machine (numerical aperture of the lens; 0.45), and exposure is performed using a g-line having a wavelength of 436 nm, or a reduction projection exposure machine (Nikon-NSR1505i6A, Exposure was performed using an i-ray having a wavelength of 365 nm while changing the exposure time according to the numerical aperture of the lens; 0.45), and then 2.4% by weight of tetramethylammonium hydroxide
Using an aqueous solution, develop at 25 ° C. for 60 seconds, rinse with water and dry to form a resist pattern on the wafer, 0.6 μm
Line and space pattern (1LIS)
(Hereinafter referred to as “optimal exposure time”).

Resolution: The dimension of the smallest resist pattern that was resolved when exposed at the optimal exposure time was measured.

Remaining film ratio: The thickness of the pattern after development at the optimal exposure time was divided by the thickness of the resist film before development, and this value was multiplied by 100 to give a unit of%.

Developability: The degree of scum and residual development was examined.

Heat resistance: The wafer at which the resist pattern was formed was placed in a clean oven, and the temperature at which the pattern began to collapse was measured.

Pattern shape: lower side A and upper side B of a rectangular cross section after development of a 0.6 μm resist pattern using a scanning electron microscope
Was measured, and when 0.85 ≦ B / A ≦ 1, the pattern shape was determined to be good.

1) Synthesis of novolak resin (1) In a flask equipped with a stirrer, cooling tube and thermometer,
m-cresol 58.0 g (0.536 mol), 2,5-xylenol 40.9 g (0.335 mol): 2,3,5-trimethylphenol 9.
13g (0.0670 mol), 372.4% by weight formaldehyde aqueous solution (formalin) 122.4 g (formaldehyde: 1.508 mol)
And 1.52 g (0.0121 mol) of oxalic acid dihydrate, the flask was immersed in an oil bath, the internal temperature was maintained at 100 ° C., and the mixture was condensed for 2 hours with stirring, followed by 14.5 g of m-cresol ( 0.134 mol), 40.9 g of 2,5-xylenol (0.33
5 mol) and 36.5 g of 2,3,5-trimethylphenol (0.2
(68 mol) and condensed for 4 hours to synthesize a novolak resin. Thereafter, the temperature of the oil bath was raised to 180 ° C., and simultaneously the pressure in the flask was reduced to 30 to 50 mmHg, and water, oxalic acid, unreacted formaldehyde, m-cresol,
2,5-xylenol and 2,3,5-trimethylphenol were removed. Next, the molten novolak resin was returned to room temperature and collected (hereinafter, this novolak resin is referred to as “resin (1)”).

2) Synthesis of Novolac Resin (2) Synthesis of Novolak Resin
-Cresol 56.7 g (0.524 mol), 2,5-xylenol 2
0.0 g (0.164 mol), 2,3,5-trimethylphenol 17.8
g (0.131 mol), formalin 119.6 g (formaldehyde: 1.47 mol) and oxalic acid dihydrate 1.49 g (0.0118 mol)
Mol), and the flask is immersed in an oil bath.
After performing condensation for 1.5 hours while stirring, 14.2 g (0.131 mol) of m-cresol, 20.0 g (0.164 mol) of 2,5-xylenol and 71.3 g (0.524 mol) of 2,3,5-trimethylphenol were further added. ) And condensation is carried out for 4 hours.
Novolak resin was synthesized. Thereafter, the novolak resin was recovered in the same manner as in the synthesis of the novolak resin (1) (hereinafter, this novolak resin is referred to as “resin (2)”).

3) Synthesis of novolak resin (3) Synthesis of novolak resin
-Cresol 71.6 (0.662 mol), 2,5-xylenol 1
0.1 g (0.0827 mol), 2,3,5-trimethylphenol 18.
0 g (0.132 mol), p-cresol 14.3 g (0.132 mol), formalin 133.0 g (formaldehyde: 1.64 mol) and oxalic acid dihydrate 1.65 g (0.0131 mol) were charged, and the flask was immersed in an oil bath. Keep the temperature at 100 ° C,
After condensation for 2 hours with stirring, 17.9 g (0.166 mol) of m-cresol and 10.1 g of 2,5-xylenol were further added.
(0.0827 mol) and 2,3,5-trimethylphenol 72.
2 g (0.530 mol) was added and condensation was performed for 4.5 hours to synthesize a novolak resin. Thereafter, the novolak resin was recovered in the same manner as in the synthesis of the novolak resin (1) (hereinafter referred to as “novolak resin”).
This novolak resin is referred to as “resin (3)”).

4) Synthesis of novolak resin (4) Synthesis of novolak resin
-Cresol 27.7 g (0.256 mol), 2,5-xylenol 3
9.1 g (0.320 mol), 2,3,5-trimethylphenol 17.4
g (0.128 mol), formalin 142.9 g (formaldehyde: 1.76 mol) and oxalic acid dihydrate 1.45 g (0.0115 mol)
Mol), and the flask is immersed in an oil bath.
After stirring for 2.5 hours while stirring, 7.00 g (0.0647 mol) of m-cresol, 39.1 g (0.320 mol) of 2,5-xylenol and 69.7 g (0.512 mol) of 2,3,5-trimethylphenol were added. ) And condensation for 3 hours,
Novolak resin was synthesized. Thereafter, the novolak resin was recovered in the same manner as in the synthesis of the novolak resin (1) (hereinafter, this novolak resin is referred to as “resin (4)”).

5) Synthesis of novolak resin (5) Synthesis of novolak resin
Cresol 71.6 g (0.662 mol), 2,5-xylenol 10.
1 g (0.0826 mol), 2,3,5-trimethylphenol 18.08
(0.132 mol), formalin 134.3 g (formaldehyde:
1.65 mol) and 1.50 g (0.0119 mol) of oxalic acid dihydrate, the flask was immersed in an oil bath, the internal temperature was maintained at 100 ° C., and the mixture was condensed for 2.5 hours with stirring. 17.9 g (0.166 mol), 10.5-g (0.0826 mol) of 2,5-xylenol and 72.2 g (0.530 mol) of 2,3,5-trimethylphenol were added, and condensation was performed for 3.5 hours.
Novolak resin was synthesized. Thereafter, the novolak resin was recovered in the same manner as in the synthesis of the novolak resin (1) (hereinafter, this novolak resin is referred to as “resin (5)”).

6) Synthesis of novolak resin (6) Synthesis of novolak resin
-Cresol 114.1 g (1.06 mol), 3,5-xylenol 8
5.9 g (0.703 mol), formalin 135.6 g (formaldehyde: 1.67 mol) and oxalic acid dihydrate 1.409 g (0.0
112 mol), and the flask was immersed in an oil bath.
The mixture was maintained at a temperature of 1.5 ° C. and stirred for 1.5 hours while stirring to synthesize a novolak resin. Thereafter, the novolak resin was recovered in the same manner as in the synthesis of the novolak resin (1) (hereinafter referred to as “novolak resin”).
This novolak resin is referred to as “resin (6)”).

Example 1 100 g of resin (1) and 1 mol of 2,3,4,4'-tetrahydroxybenzophenone and 1,2-naphthoquinonediazide-
25 g of a condensate with 4 mol of 5-sulfonic acid chloride (hereinafter referred to as “quinonediazide (I)”) was dissolved in 320 g of ethyl cellosolve acetate, and the solution was filtered through a membrane filter having a pore size of 0.2 μm. A solution was prepared. The obtained solution was applied on a silicon wafer having a silicon oxide film using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to obtain a thickness of 1.2 μm.
m resist film, wavelength 436nm through reticle
After exposing (g-line) light, developing, rinsing and drying, the sensitivity, resolution, residual film ratio, developability, heat resistance and pattern shape of the resist film were evaluated. First result
It is shown in the table.

Example 2 In Example 1, 100 g of resin (1) and 2,3,4,4 '
A condensate of 1 mol of tetrahydroxybenzophenone and 3.0 mol of 1,2-naphthoquinonediazide-4-sulfonic acid chloride (hereinafter referred to as "quinonediazide (II)") 25
g was mixed with a mixed solvent consisting of 256 g of ethyl cellosolve acetate and 64 g of ethyl 2-hydroxypropionate in the same manner as in Example 1 to obtain a composition of the present invention, form a resist film, and evaluate the resist film. went. The results are shown in Table 1.

Example 3 In Example 1, 100 g of resin (2) and 2,3,4,4 '
-Tetrahydroxy-3'-methoxybenzophenone 1
Of a 1,2-naphthoquinonediazide-5-sulfonic acid chloride (hereinafter referred to as "quinonediazide (I
II) "), a composition of the present invention was obtained, a resist film was formed, and the resist film was evaluated in the same manner as in Example 1 except for using 30 g. The results are shown in Table 1.

Example 4 In Example 1, 100 g of the resin (3) and 30 g of quinonediazide (III) were added to ethyl 2-hydroxypropionate 32.
A composition of the present invention was obtained in the same manner as in Example 1 except that the composition was dissolved in 0 g, a resist film was formed, and the resist film was evaluated. The results are shown in Table 1.

Example 5 A condensate of 100 g of resin (4) and 1 mol of 2,3,4-trihydroxybenzophenone with 2.5 mol of 1,2-naphthoquinodiazide-5-sulfonic acid chloride (hereinafter referred to as "quinonediazide (IV)") The composition of the present invention was obtained and a resist film was formed in the same manner as in Example 1 except that 30 g was dissolved in 320 g of ethyl 2-hydroxypropionate, and the resist film was evaluated. The results are shown in Table 1.

Example 6 In Example 1, 100 g of resin (4) and 2,3,4,5,
Condensate of 1 mol of 4'-pentahydroxybenzophenone and 4 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride (hereinafter referred to as "quinonediazide (V)") 20
A composition of the present invention was obtained and a resist film was formed in the same manner as in Example 1 except that g was used, and the resist film was evaluated. The results are shown in Table 1.

Example 7 In Example 1, 100 g of resin (1) and 2,3,4,3 ',
1 mol of 4 ', 5'-hexahydroxybenzophenone and 1,2
-A naphthoquinonediazide-5-sulfonic acid chloride condensate with 5 mol (hereinafter referred to as "quinonediazide (VI)") was dissolved in 320 g of ethyl 2-hydroxypropionate in the same manner as in Example 1 except that 20 g of the condensate was dissolved. The composition was obtained, a resist film was formed, and the resist film was evaluated. The results are shown in Table 1.

Example 8 Example 1 was repeated except that 100 g of resin (1), 10 g of quinonediazide (I) and 15 g of quinonediazide (IV) were dissolved in 320 g of ethyl 2-hydroxypropionate.
The composition of the present invention was obtained in the same manner as described above, a resist film was formed, and the resist film was evaluated. The results are shown in Table 1.

Example 9 In Example 1, 100 g of resin (1) and 20 g of quinonediazide (I) were mixed with 320 g of ethyl 2-hydroxypropionate.
g) was obtained in the same manner as in Example 1 except that the composition was dissolved in g, and a resist film was formed.
After exposure to light of 5 nm (i-line), development, rinsing and drying, the resist film was evaluated for sensitivity, resolution, residual film ratio, developability, heat resistance and pattern shape. The results are shown in Table 1.

Example 10 In Example 1, 100 g of the resin (2) and 25 g of quinonediazide (II) were mixed with 320 g of ethyl 2-hydroxypropionate.
The present invention was obtained in the same manner as in Example 1 except that the resist film was dissolved in g, a resist film was formed, and the resist film was evaluated in the same manner as in Example 9. The results are shown in Table 1.

Example 11 A composition of the present invention was obtained in the same manner as in Example 1 except that 100 g of the resin (3) and 25 g of quinonediazide (III) were used, and a resist film was formed. Similarly, the resist film was evaluated. The results are shown in Table 1.

Example 12 A composition of the present invention was obtained and a resist film was formed in the same manner as in Example 1, except that 100 g of the resin (4) and 25 g of quinodiazide (V) were used. Similarly, the resist film was evaluated. The results are shown in Table 1.

Example 13 A composition of the present invention was obtained and a resist film was formed in the same manner as in Example 1 except that 100 g of the resin (5) and 25 g of quinonediazide (1) were dissolved in 320 g of ethyl cellosolve acetate. Then, the resist film was evaluated. The results are shown in Table 1.

Comparative Example 1 A composition was obtained in the same manner as in Example 1 except that 100 g of the resin (6) and 25 g of quinonediazide (I) were used, a resist film was formed, and the resist film was evaluated. Was. The results are shown in Table 1.

Comparative Example 2 In Example 1, 100 g of the resin (6) and 25 g of quinonediazide (II) were mixed with 320 g of ethyl 2-hydroxypropionate.
Except for dissolving in g, a composition was obtained and a resist film was formed in the same manner as in Example 1, and the resist film was evaluated in the same manner as in Example 9. The results are shown in Table 1.

[Effects of the Invention] According to the radiation-sensitive resin composition of the present invention, high sensitivity, excellent developability, a good pattern shape after development, high resolution, and excellent heat resistance are used for manufacturing integrated circuits. As a result, a positive resist can be obtained.

Continuation of the front page (72) Inventor Takao Miura 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-60-177604 (JP, A) JP-A-62-150245 (JP, A) JP-A-2-222409 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 61/04-61/16 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] 1. A radiation-sensitive resin composition comprising an alkali-soluble novolak resin and a 1,2-quinonediazide compound, wherein the alkali-soluble novolak resin is m-cresol, 2,5-xylenol and 2,3,5- A radiation-sensitive resin composition, which is a resin obtained by condensing trimethylphenol with an aldehyde.