JP2569669B2 - Radiation-sensitive resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a radiation-sensitive resin composition, and more particularly to a radiation-sensitive resin for fine processing suitable for producing a highly integrated semiconductor integrated circuit. Composition.

[Conventional technology]

Since the positive resist is composed of an alkali-soluble resin and an alkali-insoluble 1,2-quinonediazide compound, the 1,2-quinonediazide compound in the radiation-irradiated portion is changed to indenecarboxylic acid and developed with a developer composed of an alkaline aqueous solution. However, the non-irradiated portion serving as the resist pattern is not developed, the deformation is extremely small, and a resist pattern faithful to the mask and having a high resolution can be obtained.

In recent years, where high integration of integrated circuits is required, positive resists are widely used. However, with the improvement of integration of integrated circuits, resolution of resists, heat resistance, developability, sensitivity, etc. are increased. Further improvements are needed. For example, a resist pattern is obtained by irradiating a thin film of a positive resist applied on a wafer with a radiation through a mask to form a latent image, and then developing the latent image with a developing solution composed of an alkaline aqueous solution. However, it is not always good, and scum (resist residue) may be generated in a radiation-irradiated portion after development, and the resolution may be reduced.

Conventionally, in order to improve the developability of a positive photoresist comprising the alkali-soluble novolak resin and a 1,2-quinonediazide compound, the content of the 1,2-quinonediazide compound has been reduced. However, in this case, there is a problem that resolution and heat resistance are reduced.

[Problems to be solved by the invention]

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide a radiation-sensitive resin composition suitable for a positive resist having good developability, high sensitivity and excellent resolution.

[Means for solving the problem]

The present invention relates to (A) (a) at least one selected from p-cresol, 2,5-xylenol, 3,5-xylenol and 2,3,5-trimethylphenol, and (b) m-
A co-condensate of cresol and (c) aldehyde,
An alkali-soluble novolak resin from which a part of low molecular weight components has been removed, (B) 1,2-quinonediazidosulfonic acid ester of trihydroxybenzophenone optionally having a substituent, tetrahydroxybenzophenone optionally having a substituent 1,2-quinonediazidosulfonic acid ester of
1,2-quinonediazidosulfonic acid ester of pentahydroxybenzophenone which may have a substituent, and hexahydroxybenzophenone which may have a substituent
It contains at least one selected from 1,2-quinonediazidesulfonic acid esters and (C) a polyhydroxybenzophenone which may have a substituent, and the content of the (C) polyhydroxybenzophenone is the alkali-soluble novolak. It is characterized by being 1 to 50 parts by weight with respect to 100 parts by weight of the resin.

The alkali-soluble novolak resin (hereinafter simply referred to as “novolak resin”) as the component (A) used in the present invention includes (a) p-cresol, 2,5-xylenol,
It is synthesized by condensing at least one selected from 3,5-xylenol and 2,3,5-trimethylphenol, (b) m-cresol, and (c) aldehyde in the presence of an acid catalyst.

(A) p-cresol, 2,5-xylenol, 3,5
The proportion of at least one selected from -xylenol and 2,3,5-trimethylphenol and (b) m-cresol is preferably (a) / (b) in the range of 2/8 to 7/3.
(Molar ratio), in particular, when (a) is p-cresol, (a) / (b) is 3/7 to 7/3 (molar ratio), (a) is 2,
In the case of 5-xylenol, 3,5-xylenol and 2,3,5-trimethylphenol, (a) / (b) is 2/8 to 6
/ 4 (molar ratio) is preferred.

Examples of the aldehyde include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, 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-methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde and the like. Of these compounds, formaldehyde, acetaldehyde, benzaldehyde and the like are preferred. These aldehydes are used alone or in combination of two or more.

The amount of aldehyde used is preferably 0.7 to 3 mol, particularly preferably 0.7 to 2 mol per mol of phenol.

As the acid catalyst, inorganic acids such as hydrochloric acid, nitric acid and sulfuric acid, and organic acids such as formic acid, oxalic acid and acetic acid are used. The amount of the acid catalyst used is 1 × 10 ^{-4 to} 5 × 10
^-1 mole is preferred.

In the condensation reaction, water is used as a reaction medium,
The phenol used does not dissolve in the aqueous aldehyde solution,
When a heterogeneous system is obtained from the beginning of the reaction, a hydrophilic solvent can be used as a reaction medium. As the hydrophilic solvent used at this time, for example, methanol, ethanol,
Examples include alcohols such as propanol and butanol, and cyclic ethers such as tetrahydrofuran and dioxane.

The use amount of these reaction media is preferably 20 to 1000 parts by weight per 100 parts by weight of the reaction raw materials.

The reaction temperature of the condensation reaction can be appropriately adjusted according to the reactivity of the reaction raw materials, but is usually 10 to 200 ° C, preferably 70 to 150 ° C.

After the completion of the condensation reaction, the internal temperature is generally raised to 130 ° C. to remove unreacted raw materials, acid catalyst and reaction medium present in the system.
Raise the temperature to 230230 ° C. and distill off volatiles under reduced pressure to recover the novolak resin.

As a method for removing a part of the low molecular weight component of the novolak resin thus obtained, there are a fractional precipitation method, a fractional dissolution method, a column fractionation method, an ultracentrifugal fractionation method, and the like, and the preferred method is a fractional precipitation method. It is. In order to remove a part of the low molecular weight component of the novolak resin by the fractional precipitation method, the novolak resin is removed by using alcohols such as methanol, ethanol, propanol and butanol; acetone, methyl ethyl ketone, methyl isopropyl ketone, diethyl ketone and cyclohexanone. Ketones; esters such as ethyl acetate, methyl formate, butyl acetate, ethyl cellosolve acetate, methyl cellosolve acetate, butyrolactone, valerolactone, ethylene carbonate and propylene carbonate; cyclic ethers such as dioxane, trioxane and tetrahydrofuran; or dimethylformamide; It is dissolved in a good solvent consisting of amides such as formamide and dimethylacetamide, and further dissolved in water; pentane, hexane, cyclohexane, cyclohexene, benzene, Hydrocarbons such as toluene; dichloromethane, chloroform,
Poor solvents consisting of halogenated hydrocarbons such as carbon tetrachloride, chlorobenzene and bromoform; linear lower monoethers such as diethyl ether, dipropyl ether and dibutyl ether; or nitriles such as acetonitrile, propionitrile and valeronitrile Is added. In this way, low molecular weight components with relatively high solubility remain in solution, while other components precipitate. By separating and collecting the precipitate, a novolak resin from which a part of low molecular weight components has been removed can be obtained. Note that a part of the low molecular weight components may be removed by an extraction method using a solution system for layer separation.

The removal layer of the low molecular weight component of the novolak resin is preferably from 1 to 50% by weight, particularly preferably from 5 to 40% by weight, based on the entire novolak resin. If the removal amount is less than 1% by weight, the developability cannot be improved, and if it exceeds 50% by weight, the sensitivity may decrease.

The polystyrene-equivalent weight average molecular weight of the novolak resin obtained by removing a part of the low molecular weight component used in the present invention is 2,000.
~ 30,000 is preferred, particularly preferably 2,500 ~ 25,000. The dispersity (weight average molecular weight in terms of polystyrene / number average molecular weight in terms of polystyrene) of the novolak resin is preferably from 4 to 21, and particularly preferably from 8 to 17.

In the composition of the present invention, an alkali-soluble resin other than the novolak resin, for example, polyhydroxystyrene or a derivative thereof, a styrene-maleic anhydride copolymer, polyvinylhydroxybenzoate, and a carboxyl group-containing (so long as the effects of the present invention are not lost) A (meth) acrylic resin or the like can be blended.

The 1,2-quinonediazide compound of the radiation-sensitive compound as the component (B) used in the present invention may be a trihydroxybenzophenone which may have a substituent, a tetrahydroxybenzophenone which may have a substituent, 1,2- of pentahydroxybenzophenone which may have a group or hexahydroxybenzophenone which may have a substituent
It is a quinonediazidesulfonic acid ester.

These 1,2-quinonediazide compounds include, for example, 2,3,4-trihydroxybenzophenone, 2,3,4-trihydroxy-3'-methylbenzophenone, 2,3,4-trihydroxy-3'-methoxy Benzophenone, 2,3,4
-Trihydroxy-4'-methylbenzophenone, 2,3,
4-trihydroxy-4'-methoxybenzophenone,
2,3,5-trihydroxybenzophenone, 3,4,5-trihydroxy-3'-methylbenzophenone, 3,4,5-trihydroxy-3'-methoxybenzophenone, 3,4,5-
Trihydroxy-4'-methylbenzophenone, 3,4,5
-Trihydroxy-4'-methoxybenzophenone, 2,
4,6-trihydroxy-3'-methylbenzophenone,
2,4,6-trihydroxy-3'-methoxybenzophenone, 2,4,6-trihydroxy-4'-methylbenzophenone, 2,4,6-trihydroxy-4'-methoxybenzophenone, 2,3,4 , 4'-tetrahydroxybenzophenone, 2,3,4,4'-tetrahydroxy-3'-methylbenzophenone, 2,3,4,4'-tetrahydroxy-3'-methoxybenzophenone, 2,3,4, 3'-tetrahydroxybenzophenone, 2,3,4,3'-tetrahydroxy-4 '
-Methylbenzophenone, 2,3,4,3'-tetrahydroxy-4'-methoxybenzophenone, 2,3,4,3'-tetrahydroxy-5'-methylbenzophenone, 2,3,4,
3'-tetrahydroxy-5'-methoxybenzophenone, 3,4,5,4'-tetrahydroxybezophenone, 3,4,
5,4'-tetrahydroxy-3'-methylbenzophenone, 3,4,5,4'-tetrahydroxy-3'-methoxybenzophenone, 3,4,5,3'-tetrahydroxybenzophenone, 3,4,5 , 3'-Tetrahydroxy-4'-methylbenzophenone, 3,4,5,3'-tetrahydroxy-4 '
-Methoxybenzophenone, 3,4,5,3'-tetrahydroxy-5'-methylbenzophenone, 3,4,5,3'-tetrahydroxy-5'-methoxybenzophenone, 2,3,4,
3'-tetrahydroxybenzophenone, 2,3,4,3'-tetrahydroxy-6'-methylbenzophenone, 2,3,4,
3'-tetrahydroxy-6'-methoxybenzophenone, 2,3,4,4'-tetrahydroxy-2'-methylbenzophenone, 2,3,4,4'-tetrahydroxy-2'-methoxybenzophenone, 2, 3,4,3'-tetrahydroxy-2'-methylbenzophenone, 2,3,4,3'-tetrahydroxy-2'-methoxybenzophenone, 3,4,5,3 '
-Tetrahydroxy-6'-methylbenzophenone, 3,
4,5,3'-tetrahydroxy-6'-methoxybenzophenone, 3,4,5,4'-tetrahydroxy-2'-methylbenzophenone, 3,4,5,4'-tetrahydroxy-2 '
-Methoxybenzophenone, 3,4,5,3'-tetrahydroxy-2'-methylbenzophenone, 3,4,5,3'-tetrahydroxy-2'-methoxybenzophenone, 2,3,4,
2'-tetrahydroxybenzophenone, 2,3,4,2'-tetrahydroxy-3'-methylbenzophenone, 2,3,4,
2'-tetrahydroxy-3'-methoxybenzophenone, 2,3,4,2'-tetrahydroxy-4'-methylbenzophenone, 2,3,4,2'-tetrahydroxy-4'-methoxybenzophenone, 2, 3,4,2'-tetrahydroxy-5'-methylbenzophenone, 2,3,4,2'-tetrahydroxy-5'-methoxybenzophenone, 3,4,5,2 '
-Tetrahydroxybenzophenone, 3,4,5,2'-tetrahydroxy-3'-methylbenzophenone, 3,4,5,
2'-tetrahydroxy-3'-methoxybenzophenone, 3,4,5,2'-tetrahydroxy-4'-methylbenzophenone, 3,4,5,2'-tetrahydroxy-4'-methoxybenzophenone, 3, 4,5,2'-tetrahydroxy-5'-methylbenzophenone, 3,4,5,2'-tetrahydroxy-5'-methoxybenzophenone, 2,2 ', 3,4,
6'-pentahydroxybenzophenone, 2 ', 3,4,5,
6'-pentahydroxybenzophenone, 2 ', 3,4,4',
5-pentahydroxybenzophenone, 2 ', 3,3', 4,5
-Pentahydroxybenzophenone, 3,3 ', 4,4', 5-
Pentahydroxybenzophenone, 2 ', 3,4,5,5'-pentahydroxybenzophenone, 2', 3,4,4 ', 5-pentahydroxy-3'-methylbenzophenone, 2', 3,
4,5,6'-pentahydroxy-4'-methylbenzophenone, 2 ', 3,4,5', 5-pentahydroxy-6'-methylbenzophenone, 2 ', 3,3', 4,5-pentane Hydroxy-6'-methylbenzophenone, 2 ', 3,3', 4,5-pentahydroxy-5'-methylbenzophenone, 3,3 ', 4,
4 ', 5-pentahydroxy-6'-methylbenzophenone, 2', 3,3 ', 4,4', 5-hexahydroxybenzophenone, 2 ', 3,3', 4,5,6'-hexahydroxy Benzophenone, 2 ', 3,4,4', 5,5'-hexahydroxybenzophenone, 2 ', 3,4,4', 5,6'-hexahydroxybenzophenone, 2,2 ', 3,3', 4,4'-hexahydroxy-
5-methylbenzophenone, 2,2 ', 3,3', 4,4'-hexahydroxy-5-methoxybenzophenone, 2,3,3 ',
4,4 ', 5'-hexahydroxy-5-methylbenzophenone, 2,3,3', 4,4 ', 5'-hexahydroxy-5-methoxybenzophenone, 2,2', 3,4,4 ' , 6'-Hexahydroxy-5-methylbenzophenone, 2,2 ', 3,4,4',
6'-hexahydroxy-5-methoxybenzophenone and the like. The compounding amount of the 1,2-quinonediazide compound is usually based on 100 parts by weight of the novolak resin.
It is used in an amount of 5 to 100 parts by weight, preferably 10 to 50 parts by weight.
If the amount is too small, the 1,2-quinonediazide compound absorbs radiation and generates a small amount of carboxylic acid, so that patterning as a resist becomes difficult.
If the amount is too large, all of the added 1,2-quinonediazide compound cannot be decomposed by short-time irradiation, and development with a developing solution composed of an alkaline aqueous solution may be difficult.

The polyhydroxybenzophenone as the component (C) used in the present invention may or may not have a substituent.

These polyhydroxybenzophenones include 2,2
4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,3,4,4'-tetrahydroxy Benzophenone, 3,
4,4 ', 5-tetrahydroxybenzophenone, 3,3', 4,5
-Tetrahydroxybenzophenone, 2,3,3 ', 4-tetrahydroxybenzophenone, 2,2', 3,4-tetrahydroxybenzophenone, 2 ', 3,4,5'-tetrahydroxybenzophenone, 2,2', 3,4,6'-pentahydroxybenzophenone, 2 ', 3,4,5,6'-pentahydroxybenzophenone, 2', 3,4,4 ', 5-pentahydroxybenzophenone, 2', 3,3 ' , 4,5-pentahydroxybenzophenone, 3,3 ', 4,4', 5-pentahydroxybenzophenone, 2 ', 3,4,5,5'-pentahydroxybenzophenone, 2', 3,3 ', 4 , 4 ', 5-hexahydroxybenzophenone, 2', 3,3 ', 4,5,6'-hexahydroxybenzophenone, 2', 3,4,4 ', 5,5'-hexahydroxybenzophenone, 2' , 3,4,4 ', 5,6'-hexahydroxybenzophenone, 2,4-dihydroxy-3'-methylbenzopheno 2,4-dihydroxy-3'-methoxybenzophenone, 2,4-dihydroxy-4'-methylbenzophenone, 2,4-dihydroxy-4'-methoxybenzophenone, 2,3,4-trihydroxy-3'-methyl Benzophenone, 2,3,4-trihydroxy-3'-methoxybenzophenone, 2,3,4-trihydroxy-4'-methylbenzophenone, 2,3,4-trihydroxy-4'-methoxybenzophenone, 2,4 , 6-trihydroxy-3 '
-Methylbenzophenone, 2,4,6-trihydroxy-
3'-methoxybenzophenone, 2,4,6-trihydroxy-4'-methylbenzophenone, 2,4,6-trihydroxy-4'-methoxybenzophenone, 2,3,4,4'-tetrahydroxy-3 ' -Methylbenzophenone, 2,3,4,
4'-tetrahydroxy-3'-methoxybenzophenone, 2,3,4,3'-tetrahydroxy-4'-methylbenzophenone, 2,3,4,3'-tetrahydroxy-4'-methoxybenzophenone, 2, 3,4,3'-tetrahydroxy-5'-methylbenzophenone, 2,3,4,3'-tetrahydroxy-5'-methoxybenzophenone, 3,4,5,4 '
-Tetrahydroxy-3'-methylbenzophenone, 3,
4,5,4'-tetrahydroxy-3'-methoxybenzophenone, 3,4,5,3'-tetrahydroxy-4'-methylbenzophenone, 3,4,5,3'-tetrahydroxy-4 '
-Methoxybenzophenone, 3,4,5,3'-tetrahydroxy-5'-methylbenzophenone, 3,4,5,3'-tetrahydroxy-5'-methoxybenzophenone, 2,3,4,
3'-tetrahydroxy-6'-methylbenzophenone, 2,3,4,3'-tetrahydroxy-6'-methoxybenzophenone, 2,3,4,4'-tetrahydroxy-2'-
Methylbenzophenone, 2,3,4,4'-tetrahydroxy-2'-methoxybenzophenone, 2,3,4,3'-tetrahydroxy-2'-methylbenzophenone, 2,3,4,3 '
-Tetrahydroxy-2'-methoxybenzophenone,
3,4,5,3'-tetrahydroxy-6'-methylbenzophenone, 3,4,5,3'-tetrahydroxy-6'-methoxybenzophenone, 3,4,5,4'-tetrahydroxy-
2'-methylbenzophenone, 3,4,5,4'-tetrahydroxy-2'-methoxybenzophenone, 3,4,5,3'-
Tetrahydroxy-2'-methylbenzophenone, 3,4,
5,3'-tetrahydroxy-2'-methoxybenzophenone, 2,3,4,2'-tetrahydroxy-3'-methylbenzophenone, 2,3,4,2'-tetrahydroxy-3'-
Methoxybenzophenone, 2,3,4,2'-tetrahydroxy-4'-methylbenzophenone, 2,3,4,2'-tetrahydroxy-4'-methoxybenzophenone, 2,3,4,
2'-tetrahydroxy-5'-methylbenzophenone, 2,3,4,2'-tetrahydroxy-5'-methoxybenzophenone, 3,4,5,2'-tetrahydroxy-3'-
Methylbenzophenone, 3,4,5,2'-tetrahydroxy-3'-methoxybenzophenone, 3,4,5,2'-tetrahydroxy-4'-methylbenzophenone, 3,4,5,2 '
-Tetrahydroxy-4'-methoxybenzophenone,
3,4,5,2'-tetrahydroxy-5'-methylbenzophenone, 3,4,5,2'-tetrahydroxy-5'-methoxybenzophenone, 2 ', 3,4,4', 5'-pentane Hydroxy-3'-methylbenzophenone, 2 ', 3,4,5,6'-pentahydroxy-4'-methylbenzophenone, 2',
3,4,4 ', 5-pentahydroxy-6'-methylbenzophenone, 2', 3,3 ', 4,5-pentahydroxy-6'-methylbenzophenone, 2', 3,3 ', 4,5 -Pentahydroxy-5'-methylbenzophenone, 3,3 ', 4,4', 5-pentahydroxy-6'-methylbenzophenone, 2,2 ',
3,3 ', 4,4'-hexahydroxy-5-methylbenzophenone, 2,2', 3,3 ', 4,4'-hexahydroxy-5-
Methoxybenzophenone, 2,3,3 ', 4,4', 5'-hexahydroxy-5-methylbenzophenone, 2,3,3 ', 4,
4 ', 5'-hexahydroxy-5-methoxybenzophenone, 2,2', 3,4,4 ', 6'-hexahydroxy-5-methylbenzophenone, 2,2', 3,4,4 ', 6 Examples thereof include dihydroxybenzophenone such as' -hexahydroxy-5-methoxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, pentahydroxybenzophenone and hexahydroxybenzophenone, with trihydroxybenzophenone and tetrahydroxybenzophenone being particularly preferred. These polyhydroxybenzophenones are used alone or in combination of two or more.

The amount of the polyhydroxybenzophenone is 1 to 50 parts by weight, preferably 2 to 30 parts by weight, based on 100 parts by weight of the novolak resin. If the amount is less than 1 part by weight, the developability cannot be improved, and if it exceeds 50 parts by weight, heat resistance, dry etching resistance, etc., deteriorate.

The composition of the present invention may contain a sensitizer for improving the sensitivity as a resist. Examples of sensitizers include 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, alloxane , Maleimides and the like are used. The compounding amount of the sensitizer is usually 100 parts by weight or less, preferably 4 to 60 parts by weight, based on 100 parts by weight of the 1,2-quinonediazide compound.

Further, the composition of the present invention may contain a surfactant or the like in order to improve applicability, for example, developability of a radiation-irradiated portion after striation or formation of a dried coating film. As the surfactant and the like, for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether,
Polyoxyethylene monoalkyl ethers such as polyoxyethylene oleyl ether; polyoxyethylene monoalkyl phenol ethers such as polyoxyethylene octyl phenol ether and polyoxyethylene nonyl phenol ether; polyethylene glycol dialkyl such as polyethylene glycol dilaurate and polyethylene glycol distearate Nonionic surfactants such as esters, F-Top EF301, EF303, EF35
2 (manufactured by Shin-Akita Chemical Co., Ltd.), Mega Fuck F171, F172, F173
(Manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S
Fluorine surfactants such as -382, SC101, SC102, SC103, SC104, SC105, S106 (manufactured by Asahi Glass Co., Ltd.), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and acrylic or methacrylic acid (co) heavy Combined polyflow No.75, N
o.95 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and the like. The amount of the surfactant is usually 2 parts by weight or less, preferably 1 part by weight or less, per 100 parts by weight of the solid content of the composition of the present invention.

In the composition of the present invention, to visualize the latent image of the irradiated part, or to reduce the influence of halation at the time of irradiation, a coloring agent is added, and an adhesion aid is added to improve the adhesiveness. Can also.

Further, the composition of the present invention may optionally contain a storage stabilizer, an antifoaming agent, and the like.

The composition of the present invention, a solvent, the novolak resin, 1,
It is prepared by dissolving a predetermined amount of a 2-quinonediazide compound and various compounding agents, for example, by filtering through a filter having a pore diameter of about 0.2 μm, and applying the resultant to a silicon wafer or the like by spin coating, flowing coating, roll coating or the like.

As the solvent used at this time, for example, ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether , Diethylene glycol dialkyl ethers such as diethylene glycol dibutyl ether, ethylene glycol monoalkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol pro Propylene glycol monoalkyl ether acetates such as ether acetate,
Aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone and cyclohexanone, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, oxyacetic acid Ethyl, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate And esters such as ethyl acetate, butyl acetate, methyl acetoacetate, and ethyl acetoacetate. These solvents may be used alone or in combination of two or more. Furthermore, benzyl ethyl 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, ethylene carbonate,
High boiling solvents such as propylene carbonate and phenyl cellosolve acetate can 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, or pyrrole, piperidine, 1,8-diazabicyclo (5,4,0) -7-undecene, 1,5-diazabicyclo (4,
An alkaline aqueous solution obtained by dissolving a cyclic amine such as 3,0) -5-nonane is used.

Further, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent, for example, an alcohol such as methanol or ethanol or a surfactant to the developer may be used as the developer.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

<Preparation of 1,2-quinonediazide compound> 1) Preparation of 1,2-quinonediazide compound a 2,3,4,4'-tetrahydroxybenzophenone 24.6 g
(0.1 mol) and 80.6 g (0.3 mol) of 1,2-naphthoquinonediazide-5-sulfonyl chloride were dissolved in 560 g of dioxane, and 33.5 g of triethylamine was slowly added dropwise while stirring so that the liquid temperature did not exceed 35 ° C. . Then, the precipitated triethylamine hydrochloride was removed by filtration, and the filtrate was poured into a large amount of diluted hydrochloric acid. The resulting precipitate was collected by filtration and dried at 40 ° C. for 24 hours to obtain a 1,2-quinonediazide compound (the obtained compound was referred to as “1,2-quinonediazide”).
Quinone diazide compound a "). The composition of the 1,2-quinonediazide compound a is 0.66% by weight of unreacted 2,3,4,4'-tetrahydroxybenzophenone, and the monoester 6.
92% by weight, diester 6.79% by weight, triester 39.19
% By weight, and 46.43% by weight of a tetraester.

2) Production of 1,2-quinonediazide compound b 67.2 g (0.25 mol) of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 28.3 g of triethylamine (0.
1) The same treatment as in the production of 1,2-quinonediazide compound a was carried out except that 28 mol) was used to obtain a 1,2-quinonediazide compound (the obtained compound was referred to as "1,2-quinonediazide compound b"). ). The composition of the 1,2-quinonediazide compound b was 1.27% by weight of unreacted 2,3,4,4'-tetrahydroxybenzophenone, 6.43% by weight of a monoester,
The diester was 11.67% by weight, the triester 43.54% by weight, and the tetraester 37.09% by weight.

3) Production of 1,2-quinonediazide compound c 53.7 g (0.2 mol) of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 22.2 g (0.2 mol) of triethylamine
1) The same treatment as in the production of 1,2-quinonediazide compound a was performed except that 2 mol) was used to obtain a 1,2-quinonediazide compound (the obtained compound was referred to as "1,2-quinonediazide compound c"). ). The composition of the 1,2-quinonediazide compound c was 1.76% by weight of unreacted 2,3,4,4'-tetrahydroxybenzophenone, 8.31% by weight of a monoester, 18.07% by weight of a diester, 43.62% by weight of a triester, and 28.24% of a tetraester. % By weight.

<Synthesis of Novolak Resin> 1) Synthesis of Novolak Resin A In a flask equipped with a stirrer, a condenser and a thermometer, 324 g (3 mol) of m-cresol, 216 g (2 mol) of p-cresol, 446 g of a 37% by weight aqueous solution of formaldehyde and After charging 0.22 g of oxalic acid, the flask was immersed in a hot water bath,
The reaction was carried out for 6 hours while maintaining the internal temperature at 100 ° C.

Then, the oil bath temperature was raised to 180 ° C., and simultaneously, the pressure in the flask was reduced, and water, unreacted formaldehyde, m
-To remove cresol, p-cresol, oxalic acid,
The novolak resin was recovered (hereinafter, referred to as "novolak resin A"). The polystyrene-equivalent weight average molecular weight of this novolak resin A was 19,200 and the degree of dispersion was 23.5.

2) Synthesis of novolak resin B 200 g of novolak resin A and 800 g of methanol were placed in a flask and dissolved. Then, 1500 g of water was gradually added to this solution to precipitate a novolak resin, and the precipitate was dried to obtain a novolak resin (hereinafter, referred to as "novolak resin B"). The polystyrene-equivalent weight average molecular weight of this novolak resin B was 24,600, and the degree of dispersion was 13.0.
The removal rate of the low molecular weight component of the novolak resin B was 20% by weight.

3) Synthesis of novolak resin C In a flask equipped with a stirrer, condenser and thermometer, 54 g (0.5 mol) of m-cresol, 244 g (2.0 mol) of 3,5-xylenol, 385 g of a 37% by weight aqueous solution of formaldehyde and 0.22 g of oxalic acid After charging, this flask is immersed in an oil bath,
The reaction was carried out for 1 hour while maintaining the internal temperature at 100 ° C. Thereafter, 216 g (2.0 mol) of m-cresol and 61 g (0.5 mol) of 3,5-xylenol were continuously charged into the flask as the reaction progressed, and reacted for 2 hours. Then raise the oil bath temperature to 180
C., and simultaneously the pressure inside the flask was reduced to remove water, unreacted formaldehyde, m-cresol, 3,5-xylenol, oxalic acid, and the like, and the novolak resin was recovered. The polystyrene-converted weight average molecular weight of this novolak resin was 3,100.

200 g of this novolak resin and 800 g of methanol were placed in a flask and dissolved. Then, 1800 g of water was gradually added to the solution to precipitate a novolak resin, and the precipitate was dried to obtain a novolak resin (hereinafter, referred to as "novolak resin C"). The polystyrene-equivalent weight average molecular weight of this novolak resin C was 3,500, and the degree of dispersion was 15.0. The removal rate of low molecular weight components of novolak resin C was 15%.
% By weight.

4) Synthesis of novolak resin D In a flask equipped with a stirrer, condenser and thermometer, 216 g (2.0 mol) of m-cresol, 2,3,5-trimethylphenol
68 g (0.5 mol), 446 g of 37 wt% formaldehyde aqueous solution
After charging 0.22 g of oxalic acid, the flask was immersed in an oil bath and reacted for 2 hours while maintaining the internal temperature at 100 ° C. Thereafter, 54 g (0.5 mol) of m-cresol, 2,3,
272 g (2.0 mol) of 5-trimethylphenol was continuously charged into the flask as the reaction progressed, and reacted for 3.5 hours. Then, the temperature of the oil bath was raised to 180 ° C., and simultaneously, the pressure in the flask was reduced, and water, unreacted formaldehyde, m
-Cresol, 2,3,5-trimethylphenol, oxalic acid, etc. were removed, and the novolak resin was recovered. The polystyrene-equivalent weight average molecular weight of this novolak resin was 4,900.

200 g of this novolak resin and 800 g of methanol were placed in a flask and dissolved. Then, 1800 g of water was gradually added to the solution to precipitate a novolak resin, and the precipitate was dried to obtain a novolak resin (hereinafter, referred to as "novolak resin D"). The novolak resin D had a polystyrene equivalent weight average molecular weight of 5,500 and a polydispersity of 13.8. The removal rate of the low molecular weight component of the novolak resin D was 10% by weight.

Example 1 10 g of novolak resin B, 1,2-quinonediazide compound a2.
2 g and 1.0 g of 2,3,4-trihydroxybenzophenone were dissolved in 30 g of ethyl cellosolve acetate, and the pore size was 0.2 μm.
To obtain a solution of the radiation-sensitive resin composition. This solution was spin-coated on a silicon wafer with a spinner, and prebaked on a hot plate at 90 ° C. for 2 minutes to form a 1.2 μm thick resist layer.
Next, exposure was carried out with a stepper (4800DSW manufactured by GCA), and 25 ° C
Was developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide for 60 seconds and rinsed with water to form a resist pattern. Here, when the exposure time (hereinafter referred to as “sensitivity”) for accurately forming a line-and-space pattern of the resist pattern of 1.2 μm or more was determined, the exposure time was good at 0.30 seconds, and no scum was observed. Was. When the wafer on which the pattern was formed was post-baked for 2 minutes using a hot plate, the temperature at which the pattern was deformed was 130 ° C. The results are shown in Table 1.

Comparative Example 1 Novolak resin A (10 g) and 1,2-quinonediazide compound (a2.2 g) were dissolved in ethyl cellosolve acetate (30 g) to prepare a radiation-sensitive resin composition in the same manner as in Example 1,
A resist pattern was formed. The results are shown in Table 1. The sensitivity was 0.35 seconds, and scum was observed in the exposed area.

Examples 2 and 3, Comparative Examples 2 and 3 In Example 1, except that the amount of 2,3,4-trihydroxybenzophenone used was changed to the amount shown in Table 1, the sensitivity was changed in the same manner as in Example 1. A radiation-sensitive resin composition was prepared, and a resist pattern was prepared. The results are shown in Table 1.

Example 4 In Example 1, novolak resin B was replaced with novolak resin C, and instead of 2.2 g of 1,2-quinonediazide compound a, 3.5 g of 1,2-quinonediazide compound b3.5 g was used.
2,4 instead of 1.0 g of 3,4-trihydroxybenzophenone
A radiation-sensitive resin composition was prepared in the same manner as in Example 1 except that 0.2 g of 3,4,4'-tetrahydroxybenzophenone was used, and a resist pattern was prepared. The results are shown in Table 1.

Comparative Example 4 In Example 4, a radiation-sensitive resin composition was prepared in the same manner as in Example 1 except that 2,3,4,4'-tetrahydroxybenzophenone was not added, and a resist pattern was prepared. Was tested. The results are shown in Table 1.

Example 5 In Example 1, novolak resin B was replaced with novolak resin D, and instead of a2.2 g of 1,2-quinonediazide compound, 4.0 g of 1,2-quinonediazide compound c4.0 g was used.
Instead of 1.0 g of 2,3,4-trihydroxybenzophenone
A radiation-sensitive resin composition was prepared in the same manner as in Example 1 except that 0.2 g of 2,3,4,4'-tetrahydroxybenzophenone was used, and a resist pattern was prepared. The results are shown in Table 1.

Comparative Example 5 A radiation-sensitive resin composition was prepared in the same manner as in Example 1 except that 2,3,4,4'-tetrahydroxybenzophenone was not added, and a resist pattern was prepared. The results are shown in Table 1.

〔The invention's effect〕

According to the present invention, it is possible to obtain a radiation-sensitive resin composition suitable for a positive photoresist having high sensitivity, developability without scum, and excellent resolution.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-158440 (JP, A) JP-A-62-260146 (JP, A) JP-A-60-31138 (JP, A) JP-A-60-158 176034 (JP, A) JP-A-60-189739 (JP, A)

Claims (1)

(57) [Claims] (A) (a) (a) at least one selected from p-cresol, 2,5-xylenol, 3,5-xylenol and 2,3,5-trimethylphenol, and (b) m-
A co-condensate of cresol and (c) aldehyde,
(B) 1,2-quinonediazidosulfonic acid ester of trihydroxybenzophenone which may have a substituent, and tetrahydroxybenzophenone which may have a substituent. Of 1,
From 2-quinonediazidesulfonic acid ester, 1,2-quinonediazidosulfonic acid ester of pentahydroxybenzophenone optionally having substituent (s), and 1,2-quinonediazidesulfonic acid ester of hexahydroxybenzophenone optionally having substituent (s) At least one chosen
Species, and (C) a polyhydroxybenzophenone which may have a substituent, wherein the content of the (C) polyhydroxybenzophenone is 1 to 100 parts by weight of the alkali-soluble novolak resin.
A radiation-sensitive resin composition, wherein the amount is from 50 to 50 parts by weight.