JP2002099089A - Radiation sensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation sensitive composition effectively responding to electronic beams and excellent in roughness, etching resistance, and sensitivity and capable of forming a minute pattern highly accurately and stably. SOLUTION: This radiation sensitive composition contains the following (A) and (B): (A) a compound represented by formula (1). (Wherein, R1, R2 and R3 each independently represent hydrogen atom or a t-butoxycarbonyl group. At least one of R1, R2 and R3 is hydrogen atom and at least one of R1, R2 and R3 is a t-butoxycarbonyl group). (B) a compound generating an acid by irradiation with radioactive rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a radiation-sensitive composition suitable for fine processing. More specifically, the present invention relates to a radiation-sensitive composition particularly suitable for forming a fine pattern by irradiation with an electron beam.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit elements, design rules in lithography have been rapidly miniaturized in order to obtain a higher degree of integration of integrated circuits. The development of a lithography process that can stably perform lithography has been strongly promoted.

[0003] However, it is difficult to form a fine pattern of 100 nm or less with high precision by a conventional method using a KrF or ArF excimer laser, and therefore, a method using an electron beam has been proposed.

As the electron beam resist material used for such ultra-fine processing, (1) a methacrylic main chain-cutting positive resist such as PMMA (polymethyl methacrylate), and (2) a crosslink having a chloromethyl group and an epoxy group. Negative resist, (3) a chemically amplified positive resist having a polyhydroxystyrene resin (KrF excimer resin) and a novolak (i-line resin) partially protected with an acid dissociable functional group and an acid generator; (4) Positive and negative resists containing (amorphous) organic low-molecular-weight compounds having a thin film forming ability such as calixarene and fullerene.

The positive resist (1) is excellent in resolution, but has problems in etching resistance and sensitivity, and is difficult to put into practical use. Poly-t-butyl α-chloromethylstyrene excellent in balance between resolution and sensitivity (Japanese Patent Laid-Open No. 2000-1477)
No. 77) and a patent application in which atoms (N, O, S) which are easily cut by an electron beam are introduced into the terminal of the resin (Japanese Patent Laid-Open No. 11-2).
No. 9612), although the sensitivity is improved, the sensitivity and the etching resistance are not at the practical level. The negative resist of (2) has low sensitivity and an increased molecular weight due to electron beam irradiation, and therefore swells in a developing solution and is difficult to apply to a fine process.

The chemical amplification type positive resist (3) has high sensitivity, but since a resin is used, film formation becomes rough (hereinafter referred to as roughness) when a fine pattern is formed.
Regarding the resist (4), see JP-A-11-322656.
JP, JP-A-11-72916 and JP-A-9-92
Japanese Patent No. 236919 discloses a resist using calixarene. Although the resist and the resist are excellent in etching resistance, a satisfactory pattern cannot be obtained due to structurally very strong interaction between molecules and poor solubility in a developing solution. JP-A-7-134413, JP-A-9-212962, JP-A-10-28
JP-A-2649, JP-A-11-143074 and JP-A-11-258796 disclose resists using fullerenes. This resist has good etching resistance, but its coatability and sensitivity have not reached practical levels.

[0007] Other than calixarenes and fullerenes, 1,3,5-
Tris [4- (2-t-butoxycarbonyloxy) phenyl] benzene (J. Photo Sci and Te)
ch VOL12 No2 375-376 (199
9)) Chemically amplified resists have been proposed, but have not reached practical levels due to problems in applicability, adhesion to substrates, resolution, and sensitivity.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a radiation-sensitive composition suitable for fine processing. Another object of the present invention is to provide a radiation-sensitive composition which is excellent in roughness, etching resistance and sensitivity and can form a fine pattern with high accuracy and stability. Still another object of the present invention is to provide a radiation-sensitive composition as a chemically amplified positive resist suitable for an electron beam that effectively responds to an electron beam. Still other objects and advantages of the present invention will become apparent from the following description.

[0009]

According to the present invention, the above objects and advantages of the present invention are as follows: (A) The following formula (1)

[0010]

Embedded image

Wherein R ¹ , R ² and R ³ are each independently a hydrogen atom or a t-butoxycarbonyl group, provided that at least one of R ¹ , R ² and R ³ is a hydrogen atom And at least one is a t-butoxycarbonyl group) (hereinafter also referred to as “specific compound”) and (B) a compound that generates an acid upon irradiation (hereinafter, referred to as “specific compound”). (Acid generator).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. (A) Specific Compound The specific compound used in the present invention is a compound having at least one t-butoxycarbonyl group which is an acid dissociable protecting group and at least one free hydroxyl group not protected by the acid dissociable protecting group. . The other one group may be a hydroxyl group or a t-butoxycarbonyl group. In the radiation-sensitive composition of the present invention, R in the above formula (1)
A compound corresponding to a compound in which ¹ , R ² and R ³ are all hydrogen atoms and / or in the above formula (1), R ¹ ,
Compounds corresponding to compounds in which R ² and R ³ are all t-butoxycarbonyl groups (hereinafter, these compounds may also be referred to as “other compounds”) may be included. In radiation-sensitive composition of the present invention, R ^1, R ² and R ³ and R ^1, of the specific compound in the whole group corresponding to R ² and R ³ t-butoxycarbonyl group of the other compounds of the specific compound Is preferably 1 to 99 mol%,
It is more preferably from 5 to 85 mol%, particularly preferably from 10 to 75 mol%. If the amount is less than 1 mol%, the resolution as a resist may decrease. If the amount exceeds 99 mol%, the sensitivity, resolution, and adhesion to a substrate as a resist may decrease. (B) Acid Generator The (B) acid generator used in the present invention generates an acid directly or indirectly by radiation (for example, a reaction involving electrons generated from a substance ionized by electron beam irradiation). Consisting of the following compounds:

The acid generator is not particularly limited, and examples thereof include an onium salt compound, a sulfonimide compound, a disulfone compound, and an oxime sulfonate compound. Examples of these (B) acid generators are shown below. Examples of the onium salt compound include the following formula (2):
(3)

[0014]

Embedded image

[0015]

Embedded image

(In the formulas (2) and (3), R ^{4 to} R ¹⁸
Are the same or different and represent a hydrogen atom, a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkoxy group, a hydroxyl group or a halogen atom. X
Represents an alkyl group, an aryl group, a halogen-substituted alkyl group or a halogen-substituted aryl group). Specific examples of onium salt compounds include: a. The following compounds can be mentioned as sulfonium salts.

Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, diphenyl-4-t-butyl Phenylsulfonium trifluoromethanesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium trifluoromethanesulfonate, diphenyl-4-t-
Butoxyphenylsulfonium trifluoromethanesulfonate, diphenyl-4-t-butoxyphenylsulfonium nonafluoro-n-butanesulfonate, diphenyl-4-hydroxyphenylsulfonium trifluoromethanesulfonate, bis (4-fluorophenyl)
-4-hydroxyphenylsulfonium trifluoromethanesulfonate, diphenyl-4-hydroxyphenylsulfonium nonafluoro-n-butanesulfonate, bis (4-hydroxyphenyl) -phenylsulfoniumtrifluoromethanesulfonate, tri (4-methoxyphenyl) sulfoniumtrifluoromethanesulfonate , Tri (4-fluorophenyl) sulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfoniumbenzenesulfonate, diphenyl-2,4,6-trimethylphenyl-p-toluenesulfonate, diphenyl-2,4,6 -Trimethylphenylsulfonium-2-
Trifluoromethylbenzenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium-4-trifluoromethylbenzenesulfonate, diphenyl-
2,4,6-trimethylphenylsulfonium-2,4-
Difluorobenzenesulfonate, diphenyl-2,4,
6-trimethylphenylsulfonium hexafluorobenzenesulfonate, diphenylnaphthylsulfonium trifluoromethanesulfonate, diphenyl-4-hydroxyphenylsulfonium-p-toluenesulfonate, triphenylsulfonium 10-camphorsulfonate and diphenyl-4-hydroxyphenylsulfonium 10-camphorsulfonate. b. The following compounds can be mentioned as iodonium salts.

Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate,
Butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium p-toluenesulfonate, bis (4-t -Butylphenyl) iodoniumbenzenesulfonate, bis (4-t-butylphenyl) iodonium-2-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium-4-trifluoromethylbenzenesulfonate, bis (4- t-butylphenyl) iodonium-
2,4 difluorobenzenesulfonate, bis (4-t-
Butylphenyl) iodonium hexafluorobenzenesulfonate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate,
Diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium benzenesulfonate, diphenyliodonium 10-camphorsulfonate, diphenyliodonium-2-trifluoromethylbenzenesulfonate, diphenyliodonium-4
-Trifluoromethylbenzenesulfonate, diphenyliodonium-2,4 difluorobenzenesulfonate, diphenyliodonium hexafluorobenzenesulfonate, di (4-trifluoromethylphenyl) iodonium trifluoromethanesulfonate, di (4-
(Trifluoromethylphenyl) iodonium nonafluoro-n-butanesulfonate, di (4-trifluoromethylphenyl) iodonium perfluoro-n-octanesulfonate, di (4-trifluoromethylphenyl) iodonium p-toluenesulfonate, di (4 −
Trifluoromethylphenyl) iodonium benzenesulfonate and di (4-trifluoromethylphenyl) iodonium 10-camphorsulfonate. Examples of the sulfonimide compound include the following compounds.

The following equation (4)

[0020]

Embedded image

(In the formula (4), V is an alkylene group,
R ¹⁹ represents a monovalent group such as an alkylene group, an aryl group, a halogen-substituted alkyl group, or a halogen-substituted aryl group. ).

Specific examples of such a sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, and N- ( Trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthylimide,
N- (10-camphorsulfonyloxy) succinimide, N- (10-camphorsulfonyloxy) phthalimide, N- (10-camphorsulfonyloxy)
Diphenylmaleimide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-
2,3-dicarboximide, N- (10-camphorsulfonyloxy) naphthylimide, N- (n-octanesulfonyloxy) bicyclo [2.2.1] hept-5
-Ene-2,3-dicarboximide, N- (n-octanesulfonyloxy) naphthylimide, N- (p-toluenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3- Dicarboximide, N- (p-
Toluenesulfonyloxy) naphthylimide, N- (2
-Trifluoromethylbenzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (2-trifluoromethylbenzenesulfonyloxy) naphthylimide, N- (4- Trifluoromethylbenzenesulfonyloxy) bicyclo [2.
2.1] Hept-5-ene-2,3-dicarboximide, N- (4-trifluoromethylbenzenesulfonyloxy) naphthylimide, N- (perfluorobenzenesulfonyloxy) bicyclo [2.2.1] Hept-5
Ene-2,3-dicarboximide, N- (perfluorobenzenesulfonyloxy) naphthylimide, N-
(1-Naphthalenesulfonyloxy) bicyclo [2.2.
1] hept-5-ene-2,3-dicarboximide,
N- (1-naphthalenesulfonyloxy) naphthylimide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-
Dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) naphthylimide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.
1] Hept-5-ene-2,3-dicarboximide and N- (perfluoro-n-octanesulfonyloxy) naphthylimide. Examples of the disulfone compound include the following compounds.

The following equation (5)

[0024]

Embedded image

(In the formula (5), R ²⁰ and R ²¹ may be the same or different, and may be a linear, branched or cyclic alkyl group which may be substituted, an aryl group which may be substituted, A heteroaryl group which may be substituted or an aralkyl group which may be substituted).

Specific examples of such disulfone compounds include diphenyldisulfone, di (4-methylphenyl)
Disulfone, dinaphthyl disulfone, di (4-t-
(Butylphenyl) disulfone, di (4-hydroxyphenyl) disulfone, di (3-hydroxynaphthyl) disulfone, di (4-fluorophenyl) disulfone,
(2-fluorophenyl) disulfone, di (4-trifluoromethylphenyl) disulfone and the like can be mentioned. The following compounds can be mentioned as oxime sulfonate compounds.

The following equation (6)

[0028]

Embedded image

(In the formula (6), R ²² and R ²³ are an optionally substituted linear, branched or cyclic alkyl group,
A substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted aralkyl group).

Specific examples of such oxime sulfonate compounds include α- (methylsulfonyloxyimino)
-Phenylacetonitrile, α- (methylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α-
(Propylsulfonyloxyimino) -4-methylphenylacetonitrile, α- (methylsulfonyloxyimino) -4-bromophenylacetonitrile, and the like.

The acid generator (B) in the present invention may be used alone or in combination of two or more. In the present invention, the amount of the acid generator used is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, and still more preferably 1 to 15 parts by weight, per 100 parts by weight of the specific compound (A). Parts by weight.

If the amount is less than 0.1 part by weight, sensitivity and resolution tend to decrease, while if it exceeds 30 parts by weight, the pattern cross-sectional shape as a resist tends to decrease. Acid expansion
Dispersion controlling agent In the present invention, an acid diffusion controlling agent having an action of controlling an undesired chemical reaction in an unexposed region by controlling a diffusion phenomenon in a resist film of an acid generated from an acid generator by irradiation with radiation. Is more preferably added. By using such an acid diffusion controller, the storage stability of the resist composition is improved, and the resolution is improved. In addition, the storage time before electron beam irradiation (PCD) and the time after electron beam irradiation are improved. It is possible to suppress a change in the line width of the resist pattern due to a change in the withdrawal time (PED), and the process is extremely excellent in process stability. Examples of such an acid diffusion controlling agent include a basic compound containing a nitrogen atom, a basic compound capable of decomposing by electron beams such as a basic sulfonium compound and a basic iodonium compound.

As such a nitrogen-containing basic compound, for example, the following formula (7)

[0034]

Embedded image

(In the formula (7), R ²⁴ , R ²⁵ and R
²⁶ independently represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and the alkyl group, the aryl group and the aralkyl group may be substituted with a functional group such as a hydroxy group. ) (Hereinafter referred to as “nitrogen-containing compound (I)”), a diamino compound having two nitrogen atoms in the same molecule (hereinafter “nitrogen-containing compound (I)”).
I) ". ), A diamino polymer having three or more nitrogen atoms (hereinafter referred to as “nitrogen-containing compound (III)”), an amide group-containing compound, a urea compound, a nitrogen-containing heterocyclic compound, and the like.

Examples of the nitrogen-containing compound (I) include, for example, triethylamine, tri-n-propylamine, tri-n
-Butylamine, tri-n-pentylamine, tri-n
-Hexylamine, tri-n-heptylamine, tri-
n-octylamine, tri-n-nonylamine, tri-
n-decylamine, triethanolamine, dimethyl-
Trialkylamines such as n-dodecylamine and dicyclohexylmethylamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-
Examples thereof include aromatic amines such as nitroaniline, diphenylamine, triphenylamine and 1-naphthylamine.

As the nitrogen-containing compound (II), for example,
Ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetrakis (2-hydroxypropyl) ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis (4'-aminophenyl) propane, 2- (3'-aminophenyl) -2 −
(4'-aminophenyl) propane, 2- (4'-aminophenyl) -2- (3'-hydroxyphenyl) propane, 2- (4'-aminophenyl) -2- (4'-hydroxyphenyl) propane 1,4-bis [1 ′-(4 ″-
Aminophenyl) -1′-methylethyl] benzene and 1,3-bis [1 ′-(4 ″ -aminophenyl) -1 ′
-Methylethyl] benzene and the like.

Examples of the nitrogen-containing compound (III) include polymers of polyethyleneimine, polyallylamine and dimethylaminoethylacrylamide. Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide,
Examples thereof include N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone and N-methylpyrrolidone. Examples of the urea compound include urea, methylurea, 1,1-dimethylurea,
Examples thereof include 3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tri-n-butylthiourea.

Examples of the nitrogen-containing heterocyclic compound include imidazoles such as imidazole, benzimidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole and 2-phenylbenzimidazole; pyridine, 2-methylpyridine, -Methylpyridine, 2-
Ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, ^2,2, 2 ^,, - Toripirijin, nicotine,
In addition to pyridines such as nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline and acridine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethyl Piperazine, 1,4
-Diazabicyclo [2.2.2] octane and the like. Examples of the radiolytic base compound include compounds represented by the following formulas (8) and (9).

[0040]

Embedded image

[0041]

Embedded image

In the formula (8), R ^{27 to} R ²⁹ may be the same or different and represent a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group or a halogen atom. Equation (9)
In R, R ^{30 to} R ³¹ may be the same or different and represent a hydrogen atom, an alkyl group, an alkoxyl group or a halogen atom. Z ^- is a hydroxyl group, salicylate or RCOO ^- (R
= Indicates C ¹ -C ¹⁰ alkyl, aryl, or alkylaryl).

Specifically, triphenylsulfonium hydroxide, triphenylsulfonium salicylate, diphenyl-4-hydroxyphenylsulfonium salicylate, bis (4-t-butylphenyl) iodonium salicylate, 4-t- Butylphenyl-4-
Hydroxyphenyliodonium salicylate and the like can be mentioned. The acid diffusion controllers can be used alone or in combination of two or more.

The compounding amount of the acid diffusion controller in the present invention is as follows:
(A) Per 100 parts by weight of the specific compound, preferably
0.001 to 10 parts by weight, more preferably 0.005 to 5 parts by weight
Parts by weight, more preferably 0.01 to 3 parts by weight.
In this case, if the compounding amount of the acid diffusion controller is less than 0.001 part by weight, the resolution tends to decrease, the pattern shape, the dimensional fidelity, and the like tend to deteriorate depending on the process conditions. (Post-exposure baking) (post-exposure baking).
When the source time delay increases, the pattern shape tends to deteriorate in the upper layer of the pattern. On the other hand, when the compounding amount of the basic compound exceeds 10 parts by weight, the sensitivity as a resist, the developability of an unexposed portion, and the like tend to decrease. Additives Further, the radiation-sensitive composition of the present invention includes a dissolution controlling agent,
Various additives such as a dissolution promoter, a sensitizer, and a surfactant can be blended. When the solubility of the specific compound (A) in a developing solution such as an alkali is too high, the dissolution controlling agent has a function of controlling the solubility and appropriately reducing the dissolution rate of the low-molecular compound during development. It is. As such a dissolution controlling agent, a dissolution controlling agent that does not chemically change in the steps of baking, irradiation of radiation, development and the like of the resist film is preferable.

Examples of the dissolution controlling agent include aromatic hydrocarbons such as naphthalene, phenanthrene, anthracene and acenaphthene; ketones such as acetophenone, benzophenone and phenylnaphthyl ketone; and methyl phenyl sulfone, diphenyl sulfone and dinaphthyl sulfone. Sulfones and the like can be mentioned. These dissolution controlling agents can be used alone or in combination of two or more. The amount of the dissolution controlling agent is appropriately adjusted according to the type of the specific compound (A) used.
(A) Per 100 parts by weight of the specific compound, preferably 3
0 parts by weight or less, more preferably 10 parts by weight or less.

When the solubility of the specific compound (A) in a developing solution such as an alkali is too low, the solubility enhancer increases the solubility of the compound to appropriately increase the dissolution rate of the low molecular compound during development. It is a component that has the effect of causing As such a dissolution accelerator, one that does not chemically change in steps such as baking of a resist film, electron beam irradiation, and development is preferable. Examples of the dissolution accelerator include low-molecular-weight phenolic compounds having about 2 to 6 benzene rings, and specifically, for example, bisphenols,
Tris (hydroxyphenyl) methane and the like can be mentioned. These dissolution accelerators can be used alone or in combination of two or more.

The amount of the dissolution promoter used is (A)
The amount is appropriately adjusted depending on the type of the specific compound, but is preferably 30 parts by weight or less, more preferably 10 parts by weight or less, per 100 parts by weight of the specific compound (A). The sensitizer is a component that absorbs the energy of the irradiated radiation, transfers the energy to the acid generator, thereby increasing the amount of acid generated, and improves the apparent sensitivity of the resist. is there. As such a sensitizer, for example,
Examples include benzophenones, biacetyls, pyrenes, phenothiazines, and fluorenes. These sensitizers can be used alone or in combination of two or more.

The compounding amount of the sensitizer is determined based on (A) the specific compound 10
It is preferably at most 30 parts by weight, more preferably at most 10 parts by weight, per 0 parts by weight. The surfactant is a component having an effect of improving the coating property, striation, developability as a resist, and the like of the radiation-sensitive composition of the present invention. As such a surfactant, any of anionic, cationic, nonionic and amphoteric surfactants can be used. Among these, preferred surfactants are nonionic surfactants. Examples of nonionic surfactants include polyoxyethylene higher alkyl ethers, polyoxyethylene higher alkyl phenyl ethers, higher fatty acid diesters of polyethylene glycol, and the like, as well as FPTOP (Tochem Products). ), Megafac (Dainippon Ink and Chemicals), Florard (Sumitomo 3M), Asahi Guard, Surflon (from Asahi Glass), Pepole (Toho Chemical), KP (Shin-Etsu Chemical) And Polyflow (manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.).

The amount of the surfactant is preferably 2 parts by weight or less as an active ingredient of the surfactant per 100 parts by weight of the specific compound (A). In addition, by blending a dye or a pigment, the latent image in the exposed area can be visualized, and the effect of halation at the time of exposure can be reduced.By blending an adhesion aid, the adhesion to the substrate can be improved. it can. Solvent When the radiation-sensitive composition of the present invention is used, it is dissolved in a solvent such that the solid content concentration is preferably 1 to 20% by weight, and then, for example, filtered through a filter having a pore size of about 0.2 μm. To prepare a resist solution. Examples of the solvent used in the radiation-sensitive composition include ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; and ethylene glycol monomethyl ether and ethylene glycol monoethyl ether. Ethylene glycol monoalkyl ethers; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether; methyl lactate , Lactic acid esters such as ethyl lactate; methyl acetate , Ethyl acetate, propyl acetate, such as aliphatic carboxylic acid esters of butyl acetate;
Methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3-
Other esters such as ethyl ethoxypropionate; aromatic hydrocarbons such as toluene and xylene; ketones such as 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone; and cyclic ethers such as tetrahydrofuran and dioxane. be able to. These solvents can be used alone or in combination of two or more. When forming a resist pattern from the radiation-sensitive composition of the formation the present invention resist pattern, the solution of the radiation-sensitive composition, spin coating, cast coating, by an appropriate application method roll coating, e.g. After coating on a substrate such as a silicon wafer or a wafer coated with aluminum to form a resist film, drawing is performed with radiation, preferably an electron beam.

The drawing conditions and the like are appropriately selected according to the composition of the radiation-sensitive composition and the like. In the present invention, in order to stably form a high-precision fine pattern in radiation drawing, it is preferable to perform baking after drawing. The heating conditions vary depending on the composition of the radiation-sensitive composition and the like, but are preferably 40 to 200C, more preferably 50 to 150C.

Next, a predetermined resist pattern is formed by developing the drawn resist film with an alkali developing solution. As the alkali developer, for example,
Mono-, di- or tri-alkylamines, mono-, di- or tri-alkanolamines, heterocyclic amines, tetramethylammonium hydroxide,
At least one alkaline compound such as choline, preferably 1 to 10% by weight, more preferably 1 to 5% by weight;
An alkaline aqueous solution dissolved so as to have a concentration of is used.

Further, an appropriate amount of an alcohol such as methanol, ethanol or isopropyl alcohol or a surfactant can be added to the alkaline developer. In the case where such a developing solution composed of an alkaline aqueous solution is used, generally, it is washed with water after development.

[0053]

EXAMPLES Hereinafter, embodiments of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these embodiments. (A) Synthesis of specific compound

Synthesis Example 1 (R ¹ = t-butoxycarbonyl group, R ² = R ³ = hydrogen atom) 1,3,5-Tris (4-hydroxyphenyl) benzene (manufactured by Aldrich) 3 g of butyl acetate 20% by weight 1.62 g of di-t-butyl-di-carbonate and 0.82 g of triethylamine were slowly added dropwise to the solution, and the mixture was stirred at 60 ° C. for 7 hours. The reaction solution was added to a large amount of water, and reprecipitation purification was repeated. Finally, drying under reduced pressure was performed to obtain 3.7 g of the specific compound (A-1) in which the hydroxy group was 27% t-butoxycarbonylated.

Synthesis Example 2 (R ¹ = R ² = t-butoxycarbonyl group, R ³ = hydrogen atom) 1,3,5-Tris (4-hydroxyphenyl) benzene (manufactured by Aldrich) 3 g of butyl acetate 20% by weight 2.8 g of di-t-butyl-di-carbonate and 1.43 g of triethylamine were slowly added dropwise to the solution, and the mixture was stirred at 60 ° C. for 7 hours. The reaction solution was added to a large amount of water, and reprecipitation purification was repeated.
Finally, drying under reduced pressure was performed to obtain 4.1 g of a compound (A-2) in which the hydroxy group was 48% t-butoxycarbonylated.

Comparative Synthesis Example 1 (R ¹ = R ² = R ³ = t-butoxycarbonyl group) A solution of 3 g of 1,3,5-tris (4-hydroxyphenyl) benzene (manufactured by Aldrich) in 20% by weight of butyl acetate Then, 6.00 g of di-t-butyl-di-carbonate and 3.06 g of triethylamine were slowly added dropwise thereto, followed by stirring at 60 ° C. for 7 hours. The reaction solution was added to a large amount of water, and reprecipitation purification was repeated. Lastly, drying under reduced pressure is performed so that the hydroxy group is 100% t-
5.4 g of butoxycarbonylated compound (A-4)
I got

Comparative Synthesis Example 2 (30% t-butyloxycarbonyl group partially protected polyhydroxystyrene) 10 g of polyhydroxystyrene (VP8000 manufactured by Nippon Soda Co., Ltd. (Mw 9000 Mw / Mn = 1.1)) 20% by weight of butyl acetate 5.50 g of di-tert-butyl-di-carbonate and 2.80 g of triethylamine were slowly dropped into the solution, and the mixture was stirred for 7 hours at 60 ° C. The reaction solution was added to a large amount of water, and reprecipitation purification was repeated. The residue was dried under reduced pressure to obtain 12.0 g of polyhydroxystyrene (A-5) having a hydroxy group of 30% t-butyloxycarbonyl.

Examples 1 to 5 and Comparative Examples 1 to 4 The components shown in Table 1 (parts are based on weight) were mixed to form a uniform solution, and then the mixture was made of Teflon (registered trademark) having a pore size of 0.2 μm. Foreign matter was removed by filtration through a membrane filter to prepare a radiation-sensitive composition. Each of the obtained radiation-sensitive compositions is spin-coated on a silicon wafer having a diameter of 6 inches, and baked at 50 to 100 ° C. to obtain a film thickness of 0.3.
A μm resist film was formed, and the resist film was exposed to an electron beam using a simple electron beam direct-writing apparatus (50 keV, current density 4.5 amps). After exposure, 50-100
After baking (PEB) at 1 ° C. for 1 minute, using a 2.38 wt% tetramethylammonium hydroxide aqueous solution, developing by a paddle method at 23 ° C. for 60 seconds, washing with water for 30 seconds, After drying, a positive resist pattern was formed. Table 2 shows the evaluation results of the obtained resist patterns.

Each measurement and evaluation in the examples and comparative examples was carried out by the following methods. The exposure for forming a line-and-space pattern (1L1S) having a sensitivity design dimension of 0.15 μm with a line width of 1: 1 was defined as the optimum exposure, and the sensitivity was evaluated based on the optimum exposure. Resolution The dimension of the smallest resist pattern that was resolved when exposed at the optimal exposure was measured and defined as the resolution. For a line-and-space pattern (1L1S) having a designed surface roughness of 0.15 μm, the cross-sectional dimension of the line pattern was measured with a scanning electron microscope, and the minimum dimension was Lin,
The maximum dimension is Lout, and (Lout-Lin) is Ld
Was evaluated according to the following criteria according to the value of Ld. Ld is less than 0.01 μm: good Ld is 0.01 μm or more: bad Each component used in Examples and Comparative Examples is as follows.

[0060](A) Compound A-3: 1,3,5-tris (4-hydroxyphenyl)
Benzene (R¹= R^Two= R ^Three= Hydrogen atom)(B) Acid generator B-1: triphenylsulfonium trifluoromethane
Sulfonate B-2: diphenyliodonium trifluoromethanes
Rufonate B-3: N- (trifluoromethylsulfonyloxy)
NaphthylimideAcid diffusion controller C-1: trioctylamine C-2: 2,2^,2^,,-Tripyridinesolvent D-1: Ethyl lactate D-2: Propylene glycol monomethyl ether ace
Tate D-3: tetrahydrofuran

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

EFFECT OF THE INVENTION The radiation-sensitive composition of the present invention has excellent sensitivity and resolution, has a small surface roughness, and has a line-and-
For both the space pattern and the isolated pattern, a fine pattern can be formed with high accuracy and stability. The radiation-sensitive composition of the present invention can be very suitably used as a chemically amplified positive resist in the manufacture of semiconductor devices in which miniaturization is expected to proceed in the future.

Continued on the front page (72) Inventor Toshiaki Kadota 3-5-19 Senriyama Higashi, Suita-shi, Osaka Yuniwa Excel 410 (72) Inventor Toshiyuki Kai 1-4-303 Morikayamacho, Yokkaichi-shi, Mie F-term (reference) 2H025 AA03 AC04 AC08 AD03 BE00 BE07 BF29 BG00 CB45 FA17 4H006 AA03 AB92 BJ50

Claims (1)

[Claims] (A) The following formula (1): (Wherein R ¹ , R ² and R ³ are each independently a hydrogen atom or a t-butoxycarbonyl group, provided that at least one of R ¹ , R ² and R ³ is a hydrogen atom and at least One is a t-butoxycarbonyl group), and (B) a compound that generates an acid upon irradiation with radiation.