JPH11305444A - Chemical amplification type positive type resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical amplification type positive type resist compsn. excellent in adhesiveness to a substrate and dry etching resistance and having various good resist performances such as resolution and sensitivity by incorporating a resin contg. specified polymn. units and an acid generating agent. SOLUTION: The resist compsn. contains a resin essentially contg. (meth) acrylic ester polymn. units having 2-alkyl-2-adamantyl as an acid-cleavable group and represented by formula I and polymn. units derived from maleic anhydride and represented by formula II and an acid generating agent. In the formula I, R<1> is H or methyl and R<2> is 1-8C alkyl. The resin is obtd. by copolymerizing a monomer mixture contg. 20-70 mol.% monomer for deriving the polymn. units represented by the formula I and 20-70 mol.% monomer for deriving the polymn. units represented by the formula II. The resin may further contain other polymn. units such as units derived from norbornene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemically amplified positive resist composition used for fine processing of semiconductors.

[0002]

2. Description of the Related Art A lithography process using a resist composition is usually employed for fine processing of a semiconductor.
In lithography, the shorter the exposure wavelength, the higher the resolution in principle, as expressed by the Rayleigh diffraction limit equation. Exposure light sources for lithography used in the manufacture of semiconductors have become shorter each year, such as g-line with a wavelength of 436 nm, i-line with a wavelength of 365 nm, and a KrF excimer laser with a wavelength of 248 nm. ArF excimer laser is promising.

Since the life of a lens used in an ArF excimer laser exposure machine is shorter than that of a lens for a conventional exposure light source, it is desirable that exposure time to an ArF excimer laser beam be as short as possible. For this purpose, since it is necessary to increase the sensitivity of the resist, a so-called chemically amplified resist containing a resin having a group that is cleaved by the acid utilizing the catalytic action of an acid generated by exposure is used.

The resin used for the resist for ArF excimer laser exposure does not have an aromatic ring in order to secure the transmittance of the resist, and has an alicyclic ring instead of the aromatic ring in order to have dry etching resistance. Things are known to be good. Until now, such a resin
DC Hofer, Journal of Photopolymer Science andTe
Various resins are known as described in Chnology, Vol. 9, No. 3, pp. 387-398 (1996).

[0005]

However, conventionally known resins have a problem that they are liable to peel off due to insufficient adhesion at the time of development, especially when the polarity is insufficient. Further, since an integrated circuit is formed by dry etching using a resist layer of a resist pattern formed by lithography as a protective film, the resist is also required to have excellent dry etching resistance.

An object of the present invention is to provide a chemically amplified positive resist composition containing a resin component and an acid generator, which is suitable for excimer laser lithography such as ArF or KrF. An object of the present invention is to provide a resist having excellent dry etching properties and excellent various resist properties such as resolution and sensitivity.

The present inventors have improved the adhesiveness to a substrate and dry etching resistance by using a resin having a polymerized unit having a specific structure as a resin constituting a chemically amplified positive resist composition. That is, the present invention has been completed.

[0008]

That is, the present invention provides 2-
Chemically amplified positive resin containing a (meth) acrylate ester-based polymerized unit having alkyl-2-adamantyl as an acid-cleavable group and a polymerized unit derived from maleic anhydride, and an acid generator. The present invention provides a mold resist composition.

Here, the (meth) acrylate ester-based polymerization unit having a 2-alkyl-2-adamantyl as an acid-cleavable group refers to a 2-alkyl- (meth) acrylate represented by the following formula (I). The term refers to a unit derived from 2-adamantyl, and the polymerized unit derived from maleic anhydride refers to a unit represented by the following formula (II).

[0010]

[0011] In the formula, R ¹ represents hydrogen or methyl, R ²
Represents alkyl having 1 to 8 carbons.

The resin used in the composition of the present invention comprises a unit derived from 2-alkyl-2-adamantyl (meth) acrylate represented by the above formula (I) and maleic anhydride represented by the above formula (II) In addition to the derived polymerized units, other polymerized units can be included. As other suitable polymerized units,
Examples include a unit derived from norbornene or a derivative thereof and derived from norbornene which may be substituted and represented by the following formula (III).

[0013]

In the formula, R ³ and R ⁴ are each independently hydrogen, alkyl having 1 to 3 carbons, hydroxyalkyl having 1 to 3 carbons, carboxyl, cyano or 2 to 3 carbons which may be substituted. Or R ³ and R ⁴ together represent -C (= O) OC (= O)-
To form a carboxylic anhydride residue represented by

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The resin having a polymerized unit of the above formula (I) is described in JP-A-9-73173, and the resin having each of the polymerized units of the above formulas (II) and (III) is , T.
I. Wallow etal., Proc. SPIE, Vol.2724, pp.355-364
(1996), by combining the polymerized unit of the formula (I) and the polymerized unit of the formula (II), and optionally further combining the polymerized unit of the formula (III). , Resolution and adhesion are improved.

R ² in the formula (I) is an alkyl having 1 to 8 carbon atoms, and this alkyl is usually advantageously linear, but may be branched. Specifically, methyl,
Ethyl, n-propyl, isopropyl, n-butyl, n
-Pentyl, n-hexyl, n-octyl and the like. In the formula (I), those in which R ¹ is hydrogen, that is, those in which 2-alkyl-2-adamantyl acrylate is used as the monomer have a more remarkable effect of improving the adhesion to the substrate.

R ³ and R ⁴ in the formula (III) are each hydrogen, alkyl having 1 to 3 carbons, hydroxyalkyl having 1 to 3 carbons, carboxyl, cyano or 2 to 9 carbons.
Can be an alkoxycarbonyl of
R ³ and R ⁴ may be combined to form a carboxylic anhydride residue represented by —C (= O) OC (= O) —. When R ³ and / or R ⁴ is alkoxycarbonyl, the total carbon number defined above includes carbon atoms of carbonyl. Further, the alkoxy in the alkoxycarbonyl may further have a substituent, and specific examples of the substituent include hydroxyl. R ³
And / or specific examples when R ⁴ is alkyl include methyl, ethyl, propyl and the like, and specific examples when R ⁴ is also hydroxyalkyl include hydroxymethyl, 2-hydroxyethyl and the like,
Further, specific examples of alkoxy when R ³ and / or R ⁴ are alkoxycarbonyl include methoxy, ethoxy, tert-butoxy, 2-ethylhexyloxy,
2-hydroxyethoxy and the like.

The resin containing polymerized units of the formulas (I) and (II), and optionally also of the formula (III) comprises 2-alkyl-2-adamantyl (meth) acrylate and maleic anhydride, optionally further comprising It can be produced by copolymerizing two or three components of 2-norbornene which may be substituted as essential constituent monomers.

This resin has the formulas (I), (II) and (I)
Polymerized units other than II) may be included. Other polymerized units which may optionally contain no aromatic rings and have the formula (I)
And those having a cyclic structure such as an alicyclic ring other than (III), a lactone residue and a cyclic acid anhydride residue other than formula (II) are preferable. The alicyclic ring is particularly preferably an alicyclic hydrocarbon residue, which is also preferably a cross-linked hydrocarbon ring, such as a bornane ring, a norbornane ring, a tricyclodecane ring, a tetracyclododecane ring, and an adamantane ring. Can be More specifically, a polymer unit derived from an alicyclic ester of (meth) acrylic acid, a polymer unit derived from a vinyl ester or an isopropenyl ester of an alicyclic carboxylic acid, and the like can be given. Further, it may partially contain a free carboxyl group or an alcoholic hydroxyl group.

The resin specified in the present invention is improved in adhesion by combining the polymerized units of the formulas (I) and (II) and optionally further of the formula (III). Inclusion of a butyrolactone residue in a resin, as previously proposed by Japanese Patent Application No. 10-12406, is also effective from the viewpoint of further improving the adhesiveness. The butyrolactone residue referred to here may be unsubstituted or substituted with alkyl, and the alkyl has 1 to 1 carbon atoms such as methyl, ethyl, propyl and butyl.
It can be about four. This butyrolactone residue can be bonded to the resin substrate in the form of, for example, an ester bond or an ether bond. The position of the bond at the butyrolactone residue is not particularly limited, and may be, for example, a bond coming from the α-position (that is, the 2-position) of butyrolactone. Such a butyrolactone residue may be directly connected to the main chain of the resin, for example, in the form of an ester of acrylic acid or methacrylic acid, or a butyrolactone residue may be bonded to an alicyclic ring through an ester bond or an ether bond. Alternatively, the alicyclic ring may be in the form of an ester bond or an ether bond to the main chain of the resin.

In order to introduce a butyrolactone residue into the resin, the monomer having a butyrolactone residue is substituted with the above-mentioned 2-alkyl-2-adamantyl (meth) acrylate and maleic anhydride, or optionally further substituted. Although a method of copolymerizing with norbornene which may be used is generally employed, a method of converting a resin having a carboxyl group or an alcoholic hydroxyl group into butyrolactone ester or butyrolactone ether may also be employed.
In the esterification or etherification for introducing a butyrolactone residue into a monomer or a resin, for example, a halogen-substituted butyrolactone which may be substituted with alkyl can be used. Examples of the monomer having a butyrolactone residue include, for example, α-acryloyloxy-γ-
Butyrolactone, α-methacryloyloxy-γ-butyrolactone, α-acryloyloxy-β, β-dimethyl-
γ-butyrolactone and the like.

As the polymerized unit having a butyrolactone residue, typically, a polymer represented by the following formula (IV) can be exemplified.

[0023]

In the formula, R ⁵ represents hydrogen or methyl.

It is also effective to include a polymerized unit derived from itaconic anhydride in the resin, as described in JP-A-7-234511, from the viewpoint of adhesiveness and dry etching resistance. The term “polymerized units derived from itaconic anhydride” as used herein means those represented by the following formula (V).

[0026]

The resin for a chemically amplified positive resist is generally insoluble or hardly soluble in alkali by itself.
Some of the groups are cleaved by the action of an acid and become alkali-soluble after the cleaving. In the resin used in the present invention, the 2-alkyl-2-adamantyl group in the formula (I) is an acid. Cleavage by action. Accordingly, by having the polymerized unit of the formula (I), the resist composition containing this resin acts positively. However, if necessary, another polymerized unit having a group that can be cleaved by the action of an acid is used. May be included.

As other groups which are cleaved by the action of an acid, specifically, various esters of carboxylic acids, for example, tert-
Alkyl esters having about 1 to 6 carbon atoms represented by butyl ester, methoxymethyl ester, ethoxymethyl ester, 1-ethoxyethyl ester, 1-isobutoxyethyl ester, 1-isopropoxyethyl ester, 1-ethoxypropyl ester, 1- (2-methoxyethoxy) ethyl ester, 1- (2-acetoxyethoxy) ethyl ester, 1- [2- (1-adamantyloxy) ethoxy] ethyl ester, 1- [2- (1
-Adamantanecarbonyloxy) ethoxy] ethyl ester, acetal-type esters such as tetrahydro-2-furyl ester and tetrahydro-2-pyranyl ester, and alicyclic esters such as isobornyl ester. The monomer for leading to such a polymerization unit having a carboxylic acid ester may be an acrylic monomer such as a methacrylic acid ester or an acrylic acid ester, or a norbornene carboxylic acid ester, a tricyclodecene carboxylic acid ester, or a tetracyclodecene. Like a carboxylate ester, a carboxylate group may be bonded to an alicyclic monomer.
a et al, Journal of Photopolymer Science and Techno
, Vol. 9, No. 3, pp. 447-456 (1996), in which the alicyclic group of the alicyclic carboxylic acid ester may form an ester with acrylic acid or methacrylic acid. .

The resin used in the present invention varies depending on the type of radiation for patterning exposure, the type of other polymerized units arbitrarily included, and the like. In general, the resin for leading to the polymerized unit represented by the formula (I) is used. 20-70 mol% of 2-alkyl-2-adamantyl (meth) acrylate as a monomer
And maleic anhydride which is a monomer for leading to a polymerized unit represented by the formula (II) and optionally substituted monomer which is a monomer for leading to a polymerized unit represented by the formula (III) 20-7 good norbornene
It is preferably used in the range of 0 mol%, and if necessary, other monomers are combined and copolymerized. When maleic anhydride for leading to the unit of the formula (II) and norbornene or a derivative thereof for leading to the unit of the formula (III) are copolymerized, they usually form an alternating copolymer. Formulas (I), (II) and (III)
The sum of the monomers to lead to each polymerized unit represented by
Even when other monomers are used in combination, it is advantageous to carry out the copolymerization so as to account for at least 40 mol%, preferably 50 mol% or more, of the whole monomers.

When a polymerized unit having a butyrolactone residue, for example, a polymerized unit of the formula (IV) or a polymerized unit of the formula (V) derived from itaconic anhydride is introduced, the corresponding monomer is added in an amount of 60 mol% or less, preferably Can be used in a range of 50 mol% or less. When both the polymerized unit having a butyrolactone residue and the polymerized unit derived from itaconic anhydride are introduced, it is appropriate that the total amount of the corresponding monomer is 60 mol% or less, preferably 50 mol% or less. . Furthermore, when a polymerized unit having a group that is cleaved by the action of an acid other than the polymerized unit represented by the formula (I) is introduced, the amount is preferably 50 mol% or less. Since this resin has an alicyclic ring in the polymerized unit of the formula (I),
Separately, a polymer unit having an alicyclic ring may not be provided, but the polymer unit having an alicyclic ring is preferably present in a total amount of 20 mol% or more.

The acid generator, which is another component of the resist composition of the present invention, is obtained by allowing radiation such as light or electron beam to act on the substance itself or the resist composition containing the substance. Substances decompose to generate acids. The acid generated from the acid generator acts on the resin to cleave the group that is cleaved by the action of the acid present in the resin. Such acid generators include:
For example, onium salt compounds, organic halogen compounds, sulfone compounds, sulfonate compounds and the like are included. Specifically, the following compounds can be mentioned.

Diphenyliodonium trifluoromethanesulfonate, 4-methoxyphenylphenyliodonium hexafluoroantimonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, bis (4-tert-butylphenyl) iodonium tetrafluoroborate, bis (4-tert
-Butylphenyl) iodonium hexafluorophosphate, bis (4-tert-butylphenyl) iodonium hexafluoroantimonate, bis (4-tert
-Butylphenyl) iodonium trifluoromethanesulfonate,

Triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium trifluoromethanesulfonate, 4-methoxyphenyldiphenylsulfonium hexafluoroantimonate, 4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methylphenyl Diphenylsulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-tert-
Butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-phenylthiophenyldiphenylsulfonium hexafluorophosphate, 4-
Phenylthiophenyldiphenylsulfonium hexafluoroantimonate, 1- (2-naphthoylmethyl) thiolanium hexafluoroantimonate,
1- (2-naphthoylmethyl) thiolanium trifluoromethanesulfonate, 4-hydroxy-1-naphthyldimethylsulfonium hexafluoroantimonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate,

2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2,4,6-tris (trichloromethyl) -1,3,5-triazine, 2-
Phenyl-4,6-bis (trichloromethyl) -1,3,
5-triazine, 2- (4-chlorophenyl) -4,6
-Bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4
-Methoxy-1-naphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (benzo [d] [1,3] dioxolan-5-yl) -4,6-
Bis (trichloromethyl) -1,3,5-triazine,
2- (4-methoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (3
4,5-trimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (3
4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (2,4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5 -Triazine, 2- (2-methoxystyryl) -4,6-bis (trichloromethyl) -1,3,
5-triazine, 2- (4-butoxystyryl) -4,
6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-pentyloxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine,

1-benzoyl-1-phenylmethyl p
-Toluenesulfonate (commonly called benzoin tosylate), 2-benzoyl-2-hydroxy-2-phenylethyl p-toluenesulfonate (commonly called α-methylol benzoin tosylate), 1,2,3-benzenetriyl trismethanesulfonate, , 6-Dinitrobenzyl p-toluenesulfonate, 2-nitrobenzyl p-toluenesulfonate, 4-nitrobenzyl
p-toluenesulfonate,

Diphenyl disulfone, di-p-tolyl disulfone, bis (phenylsulfonyl) diazomethane, bis (4-chlorophenylsulfonyl) diazomethane, bis (p-tolylsulfonyl) diazomethane, bis (4-tert-butylphenylsulfonyl) diazomethane, Bis (2,4-xylylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane,
(Benzoyl) (phenylsulfonyl) diazomethane,

N- (phenylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) -5-norbornene-2, 3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthalimide, N- (10-camphorsulfonyloxy) naphthalimide and the like.

In general, in a chemically amplified positive resist composition, a basic compound, particularly a basic nitrogen-containing organic compound, for example, an amine is added as a quencher to thereby form an acid accompanying the withdrawal after exposure. It is known that the deterioration of performance due to deactivation can be improved. In the present invention, it is preferable to blend such a basic compound. Specific examples of the basic compound used for the quencher include those represented by the following formulas.

[0039]

In the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ each independently represent hydrogen, alkyl, cycloalkyl, aryl or alkoxy optionally substituted by a hydroxyl group, and A represents alkylene; Represents carbonyl or imino. Here, the alkyl and alkoxy represented by R ^{11 to} R ¹⁵ can have about 1 to 6 carbon atoms, the cycloalkyl can have about 5 to 10 carbon atoms, and the aryl has The number can be on the order of 6-10. Further, the alkylene represented by A can have about 1 to 6 carbon atoms, and may be linear or branched.

The resist composition of the present invention preferably contains the resin in the range of 80 to 99.9% by weight and the acid generator in the range of 0.1 to 20% by weight based on the total solid weight. . When a basic compound is used as a quencher, the amount is 0.001 to 1% by weight, more preferably 0.001% by weight or more, and 0.2% by weight, based on the total solid weight of the resist composition. % Is preferable. The composition may also optionally include a sensitizer,
Various additives such as dissolution inhibitors, other resins, surfactants, stabilizers, and dyes may be contained in small amounts.

The resist composition of the present invention usually becomes a resist solution in a state where each of the above components is dissolved in a solvent, and is applied onto a substrate such as a silicon wafer. The solvent used here may be any as long as it dissolves each component, has an appropriate drying rate, and gives a uniform and smooth coating film after the solvent evaporates. A solvent generally used in this field is used. Can. For example, glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate, esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate, acetone, methyl isobutyl ketone, 2-heptanone And ketones such as cyclohexanone, and cyclic esters such as γ-butyrolactone. These solvents can be used alone or in combination of two or more. Among them, when 2-heptanone is used as a solvent,
Excellent results in coatability and resolution. 2-Heptanone can be used alone or in combination with another solvent. However, in order to effectively exert the above-mentioned effects, 2-heptanone is used in an amount of at least 50% by weight in the entire solvent. Advantageously.

The resist film applied on the substrate and dried is subjected to an exposure treatment for patterning, and then to a heat treatment for accelerating the deprotection reaction, and then developed with an alkali developing solution. You. The alkaline developer used here can be various alkaline aqueous solutions used in this field, but generally, aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly known as choline) are used. Often used.

[0044]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the examples, percentages and parts representing the content or the used amount are based on weight unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography using polystyrene as a standard.

Synthesis Example 1 (2-methyl-2-methacrylate)
Synthesis of adamantyl) 83.1 g of 2-methyl-2-adamantanol and 101 g of triethylamine were charged, and 200 g of methyl isobutyl ketone was added to form a solution. Thereto, 78.4 g of methacrylic acid chloride (1.5 mol times based on 2-methyl-2-adamantanol) was added dropwise, followed by stirring at room temperature for about 10 hours. After filtration, the organic layer was washed with a 5% aqueous sodium bicarbonate solution, and then twice with water. After concentrating the organic layer, it was distilled under reduced pressure to give methacrylic acid 2 represented by the following formula.
-Methyl-2-adamantyl was obtained in a yield of 75%.

[0046]

Synthesis Example 2 (Synthesis of 2-hydroxyethyl 5-norbornene-2-carboxylate) JC Jung et al., Journal of Photopolymer Science
and Technology, Vol. 10, No. 4, pp. 529-534 (1997), 150 g of dicyclopentadiene immediately after distillation was charged into a reaction vessel, and the internal temperature was kept at 40 ° C. or less. 242 g of 2-hydroxyethyl acrylate was added dropwise thereto. After dropping, 12
The mixture was stirred at room temperature for hours, and the reaction mass was distilled under reduced pressure to obtain 193 g of 2-hydroxyethyl 5-norbornene-2-carboxylate represented by the following formula (yield: 70%).

[0048]

Synthesis Example 3 (Synthesis of methyl 5-norbornene-2-carboxylate) 100 g of cyclopentadiene immediately after distillation was charged into a reaction vessel, and acryl was added thereto while maintaining the internal temperature not to exceed 40 ° C. 120 g of methyl acrylate was added dropwise (molar ratio of cyclopentadiene: methyl acrylate 1: 0.
9). After completion of the dropwise addition, stirring was continued for another 12 hours. Thereafter, by distillation under reduced pressure, 5-norbornene-
Methyl 2-carboxylate was obtained in a yield of 85%.

Synthesis Example 4 (Synthesis of 5-norbornene-2,3-dicarboxylic acid) 5-norbornene-2,3-dicarboxylic anhydride 165
g, 100 g of ethanol and 400 g of a 30% aqueous sodium hydroxide solution, and stirred at 70 ° C. for 8 hours. Thereafter, 100 g of toluene was added to the reaction mass for extraction, and then hydrochloric acid was added dropwise to the aqueous layer until the pH reached 2.0. The precipitated crystals were filtered, washed with water, and dried to give 5-norbornene-
2,3-dicarboxylic acid was obtained in a yield of 50%.

Synthesis Example 5 (Synthesis of dimethyl 5-norbornene-2,3-dicarboxylate) 5-norbornene-2 obtained by the method of Synthesis Example 4
Dissolve 30 g of 3-dicarboxylic acid in 50 g of methanol,
50 g of a 50% aqueous sodium hydroxide solution was added thereto, and 2 g
At 0 ° C., 63 g of dimethyl sulfuric acid was added dropwise. Thereafter, the mixture was stirred at room temperature for 12 hours, the reaction mass was extracted with toluene / water, and the organic layer was concentrated to give 5-norbornene-
Dimethyl 2,3-dicarboxylate was obtained in a yield of 95%.

Synthesis Example 6 (Synthesis of 5-norbornene-2-carbonitrile) 100 g of cyclopentadiene immediately after distillation was charged into a reaction vessel, and 62 g of acrylonitrile was added thereto while maintaining the internal temperature not to exceed 40 ° C. Was added dropwise (cyclopentadiene: acrylonitrile molar ratio 1: 0.
8). After completion of the dropwise addition, stirring was continued for another 12 hours. Thereafter, by distillation under reduced pressure, 5-norbornene-
2-Carbonitrile was obtained with a yield of 85%.

Synthesis Example 7 (Synthesis of 2-methyl-2-adamantyl acrylate) 166 g of 2-methyl-2-adamantanol, 303 g of triethylamine and 500 g of methyl isobutyl ketone
Was stirred at 60 ° C., and 136 g of acrylic acid chloride was added thereto.
Was added dropwise. After the addition, stirring was continued for another 6 hours, followed by extraction and distillation to give 2-methyl-acrylate.
2-adamantyl was obtained with a yield of 92%.

Synthesis Example 8 (Synthesis of Resin A1) 2-methyl-2-adamantyl methacrylate, 2-norbornene and maleic anhydride obtained in Synthesis Example 1 were used in the following manner:
It was charged at a molar ratio of 1: 1 (20.0 g: 4.0 g: 4.2 g), and methylisobutyl ketone, which was twice the weight of all monomers, was added to form a solution. Thereto, azobisisobutyronitrile as an initiator was added at 2 mol% based on the total amount of monomers, and the mixture was heated at 90 ° C. for about 8 hours. Thereafter, an operation of pouring the reaction solution into a large amount of heptane to precipitate was performed three times, and purification was performed. As a result, a copolymer having each unit of the following formula and having a weight average molecular weight of about 6,000 was obtained. This is called resin A1.

[0055]

Synthesis Example 9 (Synthesis of Resin A2) 2-methyl-2-adamantyl methacrylate, 2-norbornene and maleic anhydride in a molar ratio of 3: 1: 1 (2
Synthesis Example 8 except that the charge was 0.0g: 2.7g: 2.8g).
By the same operation as described above, a copolymer having a weight average molecular weight of about 6,000 was obtained. This is referred to as resin A2.

Synthesis Example 10 (Synthesis of Resin A3) 2-methyl-2-adamantyl methacrylate, 2-norbornene and maleic anhydride in a molar ratio of 4: 3: 3 (2
Synthesis Example 8 except that the charge was 0.0g: 6.0g: 6.3g).
By the same operation as described above, a copolymer having a weight average molecular weight of about 6,000 was obtained. This is called resin A3.

Synthesis Example 11 (Synthesis of Resin A4) 2-Methyl-2-adamantyl methacrylate, 5-norbornene-2-methanol and maleic anhydride were used in the following manner:
It was charged at a molar ratio of 1: 1 (20.0 g: 5.3 g: 4.2 g), and methylisobutyl ketone was added in an amount of 2 times by weight of all monomers to form a solution. Thereto, azobisisobutyronitrile as an initiator was added at 2 mol% based on the total amount of monomers, and the mixture was heated at 90 ° C. for about 8 hours. Thereafter, an operation of pouring the reaction solution into a large amount of heptane to precipitate was performed three times, and purification was performed. As a result, a copolymer having each unit of the following formula and having a weight average molecular weight of about 6,000 was obtained. This is designated as resin A4.

[0059]

Synthesis Example 12 (Synthesis of Resin A5) 2-Methyl-2-adamantyl methacrylate, Synthesis Example 2
The 2-hydroxyethyl 5-norbornene-2-carboxylate and the maleic anhydride obtained in the above were charged in a molar ratio of 2: 1: 1 (20.0 g: 7.8 g: 4.2 g), and 2 weight of all monomers was charged. Twice the volume of methyl isobutyl ketone was added to make a solution. After degassing by nitrogen bubbling, azobisisobutyronitrile was added as an initiator in an amount of 1 mol% based on the total amount of monomers, and the mixture was heated to 85 ° C. and stirred for 8 hours. Thereafter, an operation of pouring the reaction mass into a large amount of heptane to precipitate was performed three times to purify the reaction mass. As a result, a copolymer having each unit of the following formula and having a weight average molecular weight of about 7,000 was obtained. This is designated as resin A5.

[0061]

Synthesis Example 13 (Synthesis of Resin A6) 2-Methyl-2-adamantyl methacrylate, 2-hydroxyethyl 5-norbornene-2-carboxylate and maleic anhydride in a molar ratio of 4: 3: 3 (20. 0g: 11.7
g: 6.3 g) to obtain a copolymer having a weight average molecular weight of about 7,000, in the same manner as in Synthesis Example 12.
This is called resin A6.

Synthesis Example 14 (Synthesis of Resin A7) 2-methyl-2-adamantyl methacrylate, methyl 5-norbornene-2-carboxylate and maleic anhydride were mixed at a molar ratio of 2: 1: 1 (15 g: 7.2 g). : 3.4g)
These were dissolved in 50 g of tetrahydrofuran. Thereto, azobisisobutyronitrile was added as an initiator in an amount of 5 mol% based on the total amount of monomers, and the temperature was raised to 65 ° C. and 12%.
Stirred for hours. Thereafter, an operation of pouring the reaction mass into a large amount of heptane to precipitate was performed three times to purify the reaction mass. as a result,
A copolymer having the following formulas and having a weight average molecular weight of about 5,000 was obtained. This is called resin A7.

[0064]

Synthesis Example 15 (Synthesis of Resin A8) 2-Methyl-2-adamantyl methacrylate, 5-norbornene-2,3-dicarboxylic anhydride and maleic anhydride were mixed at a molar ratio of 2: 1: 1 (15 g: (5.6g: 3.4g)
The same operation as in Synthesis Example 14 was carried out. as a result,
A copolymer having the following formulas and having a weight average molecular weight of about 5,000 was obtained. This is called resin A8.

[0066]

Synthesis Example 16 (Synthesis of Resin A9) 2-methyl-2-adamantyl methacrylate, 5-norbornene-2-carbonitrile and maleic anhydride were used at a molar ratio of 2: 1: 1 (15 g: 4.1 g: 3.4 g), and the others were operated in the same manner as in Synthesis Example 14. As a result, a copolymer having each unit of the following formula and having a weight average molecular weight of about 5,000 was obtained.

[0068]

Synthesis Example 17 (Synthesis of Resin A10) 2-methyl-2-adamantyl methacrylate, dimethyl 5-norbornene-2,3-dicarboxylate and maleic anhydride were mixed at a molar ratio of 2: 1: 1 (15 g: 7 .2g: 3.4
g) The same procedures as in Synthesis Example 14 were carried out except for the above. As a result, a copolymer having each unit of the following formula and having a weight average molecular weight of about 5,000 was obtained. This is called resin A10.

[0070]

Synthesis Example 18 (Synthesis of Resin A11) 2-methyl-2-adamantyl acrylate, norbornene and maleic anhydride were mixed in a molar ratio of 4: 3: 3 (20 g:
6.9 g: 7.2 g), 60 g of tetrahydrofuran
Was added to form a solution. Thereto, azobisisobutyronitrile as an initiator was added in an amount of 3 mol% based on the total amount of monomers, and the mixture was heated to 65 ° C. and stirred for 8 hours. Thereafter, an operation of pouring the reaction solution into a large amount of methanol and causing precipitation was performed three times to purify the reaction solution. As a result, a copolymer having each unit of the following formula and having a weight average molecular weight of about 6,000 was obtained. This is resin A11
And

[0072]

Synthesis Example 19 (Synthesis of Resin A12) 2-Methyl-2-adamantyl acrylate and maleic anhydride were mixed at a molar ratio of 4: 3 (20 g: 7.2 g), and 2 wt. Twice the volume of tetrahydrofuran was added to form a solution. Further, 3 mol% of azobisisobutyronitrile was added as an initiator to the total amount of monomers, and then the temperature was raised to 65 ° C. and the mixture was stirred for 12 hours. After cooling the reaction mass, an operation of pouring into a large amount of methanol and precipitating was performed three times for purification. As a result, a copolymer having each unit of the following formula and having a weight average molecular weight of about 6,000 was obtained.

[0074]

Synthesis Example 20 (Synthesis of resin AX: for comparison) 1-ethoxyethyl methacrylate, isobornyl methacrylate and methacrylic acid in a molar ratio of 5: 3: 2 (31.6)
g: 26.7 g: 6.9 g), and methylisobutyl ketone in an amount 2 times the weight of all monomers was added to form a solution. Thereto, azobisisobutyronitrile as an initiator was added at 2 mol% based on the total amount of monomers, and the mixture was heated at 80 ° C. for about 8 hours. Thereafter, an operation of pouring the reaction solution into a large amount of heptane to cause precipitation was performed twice, and purification was performed. As a result, a copolymer having each unit of the following formula and having a weight average molecular weight of about 10,000 was obtained. This is called resin AX.

[0076]

Examples 1 to 8 and Comparative Examples 1 and 2 In each case, 10 parts of the resin shown in Table 1 were used,
Using 0.20 parts of -methylphenyldiphenylsulfonium trifluoromethanesulfonate (manufactured by Midori Kagaku) and 0.015 parts of 2,6-diisopropylaniline as a quencher, these were dissolved in 50 parts of a solvent shown in Table 1, and further dissolved. The solution was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist solution. This was applied to a silicon wafer (contact angle of water: 60 °) treated with hexamethyldisilazane (HMDS) or a silicon wafer coated with an organic antireflection film so that the film thickness after drying was 0.455 μm. Organic anti-reflective coatings are available from Brewer's DUV-18
L ″ was applied to a thickness of 570 ° under a baking condition of 215 ° C. for 60 seconds. A pre-bake after application of the resist solution was performed on a direct hot plate at 120 ° C. for 60 seconds. went.

The wafer having the resist film formed thereon is coated with a KrF excimer stepper [“NSR” manufactured by Nikon Corporation.
The line and space pattern was exposed using 2205 EX12B ", NA = 0.55]. Next, a post-exposure bake (PEB) was performed on a hot plate at a temperature shown in Table 1 for 60 seconds, and further, Paddle development was performed for 60 seconds using a 2.38% tetramethylammonium hydroxide aqueous solution or a developer diluted with ultrapure water as shown in Table 1. The pattern after development was observed with a scanning electron microscope. The sensitivity and resolution of the pattern obtained from the resist film provided on the organic antireflection film substrate were examined by the following methods.

Sensitivity: Displayed at an exposure amount (effective sensitivity) at which a 0.3 μm line and space pattern becomes 1: 1.

Resolution: The minimum size of the line and space pattern separated by the exposure amount of the effective sensitivity was displayed.

The adhesiveness of the pattern on the substrate on which the organic antireflection film was not provided was evaluated, and those having a 0.3 μm line and space pattern adhered to the substrate at an exposure amount of 1: 1 were evaluated as ○. , And those that were peeled were indicated by x. The above results are shown in Table 1 together with the used resin and solvent, the temperature of PEB, and the dilution ratio of the developer.

[0082]

[Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example No. Resin Solvent ^* PEB developer Effective sensitivity Resolution Adhesion Properties 例 Example 1 A1 PGMEA 120 ° C No dilution 35 mJ / cm ² 0.21μm ○ 〃 2 A1 MAK 120 ℃ No dilution 40 mJ / cm ² 0.19μm ○ ３ 3 A2 〃 120 ℃ No dilution 30 mJ / cm ² 0.19μm ○ ４ 4 A3 〃 120 ℃ No dilution 30 mJ / cm ² 0.20μm ○ 〃 5 A4 〃 120 ° C No dilution 60 mJ / cm ² 0.18μm ○ 〃 6 A4 〃 130 ° C No dilution 35 mJ / cm ² 0.20μm ○ ７ 7 A5 〃 120 ° C No dilution 40 mJ / cm ² 0.19μm ○ ８ 8 A6 〃 120 ° C No dilution 55 mJ / cm ² 0.20μm ○ 比較 Comparative Example 1 AX PGMEA 120 ° C. 1/20 dilution 40 mJ / cm ² 0.23μm ○ 〃 2 AX 〃 120 ° C. 1/5 diluted 35 mJ / cm ² 0.25μm × ━━━━━━━ ━━━━━━━━━━━━━━━━━━━━━━━━━

(Footnote to Table 1) ^* Solvent PGMEA: propylene glycol monomethyl ether acetate MAK: 2-heptanone (also known as methyl amyl ketone)

As shown in Table 1, according to the present invention, the resins A1 to A1
A resist using A6 does not peel off during development even when the concentration of the developing solution is high, and has excellent adhesion to the substrate. Also, the resolution has been improved, and the sensitivity is not significantly impaired.

Examples 9 to 16 For each example, 10 parts of the resin shown in Table 2 and 4 parts of an acid generator were used.
Using 0.20 parts of -methylphenyldiphenylsulfonium trifluoromethanesulfonate (manufactured by Midori Kagaku Co., Ltd.) and 0.015 parts of 2,6-diisopropylaniline as a quencher, dissolving them in 45 parts of 2-heptanone, The solution was filtered through a 0.2 μm fluororesin filter to prepare a resist solution. This was applied to a silicon wafer treated with hexamethyldisilazane (having a contact angle of 60 ° and 50 ° with water) or a silicon wafer coated with an organic anti-reflection film to have a dried film thickness of 0.455.
It was applied to a thickness of μm. Organic anti-reflective coating, Brewer
"DUV-42" was baked at 215 ° C for 60 seconds.
It was formed by coating so as to have a thickness of 0 °. Prebaking after the application of the resist solution was performed on a direct hot plate at 120 ° C. for 60 seconds.

The wafer on which the resist film was formed in this manner was provided with a KrF excimer stepper [NSR “NSR” manufactured by Nikon Corporation].
The line and space pattern was exposed using 2205 EX12B ″, NA = 0.55]. Next, a post-exposure bake (PEB) was performed on a hot plate at a temperature shown in Table 2 for 60 seconds. A paddle development was performed for 60 seconds with a 3.8% aqueous solution of tetramethylammonium hydroxide, and the pattern after development was observed with a scanning electron microscope, and the pattern obtained from the resist film provided on the organic antireflection film substrate was examined. The sensitivity and the resolution were examined in the same manner as in Examples 1 to 8. The pattern on the substrate not provided with the organic antireflection film was also evaluated for the adhesiveness in the same manner as in Examples 1 to 8. The results are shown in Table 2 together with the temperatures of the resin and PEB used.

In this case, a silicon wafer having a contact angle of 60 ° and a silicon wafer having a contact angle of 50 ° are used. However, the larger the contact angle of the substrate with water, the more difficult it is to wet with water, that is, the higher the organic property. And the developer is easily wetted by the resist, which is an organic substance, and the developer is less likely to penetrate into the interface between the substrate and the resist, so that peeling during development is reduced. Conversely, the smaller the contact angle with water, the more difficult it is for the resist to adhere. Therefore, it can be said that a resist that does not peel off even on a substrate having a small contact angle with water has better adhesiveness.

[0088]

[Table 2] Example No. Resin PEB Effective sensitivity Resolution adhesion Contact angle 60 ° Contact angle 50 ° 例 Example 9 A7 120 ° C 33 mJ / cm ² 0.21μm ○ × Example 10 A8 120 ° C 28 mJ / cm ² 0.21μm ○ × Example 11 A9 120 ° C 28 mJ / cm ² 0.21μm ○ × Example 12 A10 120 ° C 32 mJ / cm ² 0.22μm ○ × Example Example 13 A11 110 ° C 33 mJ / cm ² 0.20 μm ○ ○ Example 14 A11 120 ° C 25 mJ / cm ² 0.21 μm ○ ○ Example 15 A1 120 ° C 37 mJ / cm ² 0.21 μm ○ × Example 16 A12 110 ° C 25 mJ / cm ² 0.20μm ○ ○ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

As shown in Table 2, each of the examples shows good sensitivity, resolution and adhesiveness to the substrate. In particular, the resin A11 or A12 prepared from 2-methyl-2-adamantyl acrylate as a raw material was used. The resist used does not peel off during development even on a substrate having a contact angle of 50 ° with water, and the adhesion is further improved.

The patterns obtained from the resists of Examples 1 to 16 have good dry etching resistance.
In addition, these resist compositions give a resist pattern having excellent performance even when exposed with an ArF excimer laser exposure machine.

[0091]

As described above, the chemically amplified positive resist composition of the present invention has excellent adhesion to a substrate, good dry etching resistance, and excellent resist performance such as sensitivity and resolution. Is kept. Therefore, this resist composition is suitable for exposure using a KrF excimer laser, an ArF excimer laser, or the like, thereby giving a high-performance resist pattern.

Claims (7)

[Claims] (1) The following formulas (I) and (II) (Wherein, R ¹ represents hydrogen or methyl, and R ² has 1 carbon atom.
A resin comprising each polymerized unit represented by the formula (1) to (8), and an acid generator. 2. The resin comprises 20 to 70 mol% of a monomer for leading to a polymerized unit represented by the formula (I) and 20 to 70 mol% of a monomer for leading to a polymerized unit represented by the formula (II). A composition according to claim 1 obtained by copolymerization of a monomer mixture containing the composition. (3) The resin further comprises the following formula (III) (Wherein R ³ and R ⁴ are each independently hydrogen, carbon 1
Alkyl of 1-3, hydroxyalkyl of 1-3 carbons,
Carboxyl, cyano, or an optionally substituted alkoxycarbonyl having 2 to 9 carbon atoms, or R
³ and R ⁴ together form a carboxylic anhydride residue represented by -C (= O) OC (= O)-). Stuff. 4. One of R ³ and R ⁴ is hydrogen, the other is hydrogen,
The composition according to claim 3, which is alkyl having 1 to 3 carbons, hydroxyalkyl having 1 to 3 carbons, carboxyl, or alkoxycarbonyl having 2 to 9 carbons which may be substituted. 5. The resin according to claim 1, wherein said resin has 20 to 70 mol% of a monomer for leading to a polymerized unit represented by the formula (I);
5. The composition according to claim 3, which is obtained by copolymerization of a monomer mixture containing a total of 20 to 70 mol% of each monomer for leading to each of the polymer units represented by I) and formula (III). 6. The resin according to claim 1, further comprising a polymerized unit having a butyrolactone residue which may be substituted by alkyl and / or a polymerized unit derived from itaconic anhydride.
The composition according to any one of claims 1 to 5. 7. The composition according to claim 1, wherein said resin and said acid generator are dissolved in a solvent containing 2-heptanone.