JPH10274852A - Chemically amplified positive resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemically amplified positive resist composition containing a resin component and an acid generator, which is excellent in various resist performances such as sensitivity and resolution, and particularly suitable for a substrate. Provide excellent adhesiveness. SOLUTION: A chemically amplified positive resist composition containing a resin having a butyrolactone residue which may be substituted with alkyl, and an acid generator. This butyrolactone residue can be bonded to the resin substrate via an ester bond or an ether bond at the α-position, for example. Further, this resin usually further has a group which is cleaved by the action of an acid.

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. The exposure light source for lithography used in the manufacture of semiconductors has a wavelength of 436 nm.
The g-line, i-line with a wavelength of 365 nm, and KrF excimer laser with a wavelength of 248 nm are becoming shorter each year, and an ArF excimer laser with a wavelength of 193 nm is expected to be a next-generation exposure light source.

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 (1996) 387-398. However, conventionally known resins have a problem in that when the polarity is insufficient, development peeling is likely to occur due to insufficient adhesiveness during development.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a chemically amplified positive resist composition containing a resin component and an acid generator and suitable for excimer laser lithography such as ArF or KrF. Another object of the present invention is to provide a resist having excellent resist performance such as resolution and resolution, and particularly having excellent adhesiveness to a substrate.

The present inventors have found that by introducing a certain type of group into a resin constituting a chemically amplified positive resist composition, the adhesiveness to a substrate is improved. completed.

[0007]

That is, the present invention provides a chemically amplified positive resist composition comprising a resin having a butyrolactone residue which may be substituted with an alkyl, and an acid generator. is there.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The resin constituting the positive resist composition of the present invention is usually obtained by polymerization or copolymerization of a compound having an ethylenically unsaturated bond, has no aromatic ring, And what has an alicyclic ring is preferable. This alicyclic ring is particularly preferably an alicyclic hydrocarbon residue, which is also preferably a bridged hydrocarbon ring, for example, a bornane ring, a norbornane ring, a tricyclodecane ring, a tetracyclododecane ring, an adamantane ring, and the like. No. More specific resins include those having a polymerized unit derived from an alicyclic ester of (meth) acrylic acid, and those having a polymerized unit derived from a vinyl ester or isopropenyl ester of an alicyclic carboxylic acid. be able to.

In the present invention, such a resin contains a butyrolactone residue. The butyrolactone residue referred to here may be unsubstituted or substituted with alkyl, and this alkyl has about 1 to 4 carbon atoms such as methyl, ethyl, propyl and butyl. it can. 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 polymerized unit having a butyrolactone residue may further include the alicyclic ring described above therein. For example, a unit derived from an alicyclic ester of (meth) acrylic acid, in which a butyrolactone residue is bonded to the alicyclic ring through an ester bond or an ether bond, is also referred to as a butyrolactone residue. It is included in the polymerized unit having.

In order to introduce a butyrolactone residue into a resin, a method of converting a carboxylic acid group or an alcoholic hydroxyl group present in the resin or a monomer constituting the resin into a butyrolactone ester or a butyrolactone ether is employed. it can. For such esterification or etherification, for example, a halogen-substituted butyrolactone which may be substituted with alkyl can be used. When a monomer into which a butyrolactone residue is introduced is prepared, it may be polymerized as one component. Examples of such a monomer include α-acryloyloxy-γ-
Butyrolactone, α-methacryloyloxy-γ-butyrolactone, α-acryloyloxy-β, β-dimethyl-
γ-butyrolactone and the like.

In general, a resin for a chemically amplified resist is insoluble or hardly soluble in alkali by itself, but some groups are cleaved by the action of an acid and become alkali-soluble after cleaving. . Therefore, the resin used in the present invention usually has a group that is cleaved by the action of an acid, in addition to a butyrolactone residue. The alicyclic ring described above may be included in the group that is cleaved by the action of an acid.

Groups which are cleaved by the action of an acid are known in the resist field, and include, for example, an alkyl group branched at the 1-position such as tert-butyl; 1-ethoxyethyl, 1- (2
-Methylpropoxy) ethyl, 1- (2-methoxyethoxy) ethyl, 1- (2-acetoxyethoxy) ethyl, 1- [2- (1-adamantyloxy) ethoxy]
1-alkoxyalkyl groups which may be further substituted, such as ethyl and 1- [2- (1-adamantanecarbonyloxy) ethoxy] ethyl; tetrahydro-2-
Furanyl, tetrahydro-2-pyranyl, 3-oxocyclohexyl, 4-methyltetrahydro-2-pyrone-
Non-aromatic cyclic compound residues such as 4-yl (derived from mevalonic lactone) and 2-methyl-2-adamantyl, and the like. These groups are substituted with hydrogen of a carboxylic acid group or an alcoholic hydroxyl group in the resin or the monomer. When a monomer having such a group is prepared, it is copolymerized with another monomer to obtain a resin used in the present invention.

The resin used in the present invention varies depending on the type of radiation for patterning exposure and the type of a group which is cleaved by the action of an acid, but generally, the polymerization unit having a butyrolactone residue is 10 to 60. It is preferable to contain it in the range of mol%. The amount of the polymerized unit having a group that is cleaved by the action of an acid is preferably in the range of 10 to 90 mol%. When the group that is cleaved by the action of an acid has an alicyclic ring at the same time, it is not necessary to provide a polymerized unit having an alicyclic ring separately from the group. It is preferably present in an amount of at least 20 mol%. The resin may also contain other polymer units, for example, a polymer unit having a free carboxylic acid group, as long as the effects of the present invention are not impaired.

Another component, an acid generator, is used in the substance itself or in a resist composition containing the substance.
When a radiation such as light or an electron beam is applied, the substance is decomposed to generate an acid. 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. 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, especially 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.

[0022]

Wherein R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵
Each independently represents hydrogen, alkyl, cycloalkyl, aryl or alkoxy which may be substituted by a hydroxyl group, and A represents alkylene, 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 a resin in an amount of 80 to 99.9% by weight and an acid generator in an amount of 0.1 to 20% by weight based on the total solid weight. . When a basic compound is used as the quencher, the content is preferably 0.001 to 0.1% by weight based on the total solid content of the resist composition. The composition may also contain small amounts of various additives such as sensitizers, dissolution inhibitors, other resins, surfactants, stabilizers, and dyes, if necessary.

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 one that dissolves each component, has an appropriate drying speed, and provides a uniform and smooth coating film after the solvent evaporates. There can be. 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,
Examples include ketones such as methyl isobutyl ketone, 2-heptanone and cyclohexanone, and cyclic esters such as γ-butyrolactone. These solvents can be used alone or in combination of two or more.

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 a deprotection group reaction.
Developed with an alkaline developer. The alkaline developer used here can be various alkaline aqueous solutions used in this field, but generally, tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly known as choline) is used. Aqueous solutions are often used.

[0027]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Parts in the examples are by weight unless otherwise specified.

Synthesis Example 1 (Synthesis of Monomer) 100 g of α-bromo-γ-butyrolactone and 104.4 g of methacrylic acid (2.0 mol times based on α-bromo-γ-butyrolactone) were charged, and α-bromo-γ was added. -Methyl isobutyl ketone three times the weight of butyrolactone was added to form a solution. 183.6 g of triethylamine (3.0 mol times based on α-bromo-γ-butyrolactone) was added dropwise thereto, and the mixture was stirred at room temperature for about 10 hours. After filtration, the organic layer was washed with a 5% by weight aqueous sodium bicarbonate solution, and then washed twice with water. The organic layer was concentrated to obtain α-methacryloyloxy-γ-butyrolactone represented by the following formula in a yield of 8
Obtained at 5%.

[0029]

Synthesis Example 2 (Synthesis of Another Monomer) 55.1 g of 1-adamantane carbonyl chloride and 44 g of pyridine were charged, and a solution was added by adding methyl isobutyl ketone twice the weight of 1-adamantane carbonyl chloride. There ethylene glycol monovinyl ether 3
7.2 g (1.5 mol times based on 1-adamantane carbonyl chloride) was added dropwise, and the mixture was stirred at room temperature for about 10 hours. After filtration, the organic layer was washed with a 5% by weight aqueous sodium bicarbonate solution, and then washed twice with water. After concentrating the organic layer, 3 weight times 1,4-dioxane was added to form a solution,
An appropriate amount of p-toluenesulfonic acid monohydrate and 36 g of methacrylic acid were charged therein and stirred at room temperature for about 10 hours. Thereafter, the organic layer was washed with a 5% by weight aqueous solution of sodium bicarbonate, and then washed twice with water. The organic layer was concentrated to give 1-adamantanecarboxylic acid 2-
(1-methacryloyloxyethoxy) ethyl yield 75
%.

[0031]

Synthesis Example 3 (Synthesis of Another Monomer) 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 prepare 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% by weight aqueous sodium bicarbonate solution, and then washed twice with water. After concentrating the organic layer, the residue was distilled under reduced pressure to obtain 2-methyl-2-adamantyl methacrylate represented by the following formula in a yield of 75%.

[0033]

Synthesis Example 4 (Synthesis of Resin A1) 1-ethoxyethyl methacrylate, isobornyl methacrylate, and α-methacryloyloxy-γ-butyrolactone obtained in Synthesis Example 1 were in a molar ratio of 5: 3: 2. (3
(1.6 g: 26.7 g: 13.6 g), and methylisobutyl ketone in an amount of 2 times the weight of all monomers was added to form a solution. Thereto, azobisisobutyronitrile was added as an initiator in an amount of 2 mol% based on the total amount of monomers, and about 8% at 80 ° C.
Heated for 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, it is represented by the following formula, and the composition molar ratio of each unit is 50:30:20.
Thus, a copolymer having a weight average molecular weight of about 10,000 was obtained.

[0035]

Synthesis Example 5 (Synthesis of resin AX: for comparison) 1-ethoxyethyl methacrylate, isobornyl methacrylate, and methacrylic acid were mixed at a molar ratio of 5: 3: 2 (31.6 g: 26.7 g: 6.7). The same operation as in Synthesis Example 4 was carried out except for charging in 9 g). As a result, a copolymer represented by the following formula and having a composition molar ratio of each unit of 50:30:20 and a weight average molecular weight of about 10,000 was obtained.

[0037]

Synthesis Example 6 (Synthesis of Resin A2) 1-adamantanecarboxylic acid 2-
(1-methacryloyloxyethoxy) ethyl and α-methacryloyloxy-γ-butyrolactone obtained in Synthesis Example 1 were charged at a molar ratio of 8: 2 (33.7 g: 4.3 g), and all monomers were charged. A solution was added by adding 2 weight times methyl isobutyl ketone. 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, as shown in the following formula, the composition molar ratio of each unit is 8
At a ratio of 0:20, a copolymer having a weight average molecular weight of about 10,000 was obtained.

[0039]

Synthesis Example 7 (Synthesis of resin AY: for comparison) The molar ratio of 2- (1-methacryloyloxyethoxy) ethyl 1-adamantanecarboxylate and methacrylic acid was 8: 2 (33.7 g: 2.2 g). The same procedures as in Synthesis Example 6 were carried out, except that the preparations were carried out in the same manner. As a result, a copolymer represented by the following formula and having a composition molar ratio of each unit of 80:20 and a weight average molecular weight of about 10,000 was obtained.

[0041]

Synthesis Example 8 (Synthesis of Resin A3) 2-Methyl-2-adamantyl methacrylate obtained in Synthesis Example 3, 2- (1-methacryloyloxyethoxy) 1-adamantanecarboxylate obtained in Synthesis Example 2 )ethyl,
And α-methacryloyloxy-γ obtained in Synthesis Example 1.
-Butyrolactone in a molar ratio of 3: 5: 2 (23.4 g:
56.2 g: 11.3 g), and methylisobutyl ketone was added in an amount of 2 times the 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 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 represented by the following formula and having a composition molar ratio of each unit of 30:50:20 and a weight average molecular weight of about 10,000 was obtained.

[0043]

Synthesis Example 9 (Synthesis of Resin AZ) 2-Methyl-2-adamantyl methacrylate, 2- (1-methacryloyloxyethoxy) ethyl 1-adamantanecarboxylate and methacrylic acid were mixed in a molar ratio of 3: 5: 2. Except for the ratio (23.4g: 56.2g: 5.7g)
The same operation as in Synthesis Example 8 was performed. As a result, the following equation is obtained.
A copolymer having a composition molar ratio of each unit of 30:50:20 and a weight average molecular weight of about 10,000 was obtained.

[0045]

Examples 1 to 6 and Comparative Examples 1 to 6 In each case, 15 parts of the resin shown in Table 1 and 0.15 of diphenyldisulfone (manufactured by Midori Kagaku) as an acid generator were used.
Parts and 0.01 parts of the quencher shown in Table 1, were dissolved in 60 parts of propylene glycol monomethyl ether acetate, and filtered through a filter made of a fluororesin having a pore diameter of 0.2 μm to prepare a resist solution. This was applied to a silicon wafer treated with hexamethyldisilazane (HMDS) (contact angle of water: 60 °) or a silicon wafer coated with an organic anti-reflection film to have a film thickness of 0.2 after drying.
It was applied to a thickness of 72 μm. Organic anti-reflective coating, Brewe
"XHRi-11" from Company r was applied and formed to a thickness of 1,700 ° under baking conditions of 175 ° C. and 60 seconds.
Prebaking after the application of the resist solution was performed on a direct hot plate at 90 ° C. for 60 seconds.

A KrF excimer stepper [NSR “NSR” manufactured by Nikon Co., Ltd.]
The line and space pattern was exposed using 1755 EX8A ", NA = 0.45]. Next, post-exposure bake (PEB) on a hot plate under the conditions shown in Table 1.
Then, dip development was performed for 60 seconds using a 2.38 wt% tetramethylammonium hydroxide aqueous solution or a developer diluted with pure water as shown in Table 1. The developed pattern was observed with a scanning electron microscope, and 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 0.5 μm line and space pattern becomes 1: 1.

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

The pattern on the substrate not provided with the organic anti-reflection film was evaluated for adhesiveness, and was adhered to the substrate at an exposure amount such that the 0.5 μm line and space pattern became 1: 1. Is indicated by ○, and those that have been peeled off are indicated by x. The above results are shown in Table 1 together with the resist composition.
Shown in

[0051]

[Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example No. Resin quencher PEB conditions Developer effective Sensitivity Resolution Adhesion ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 1 A1 C1 100 ℃ × 60sec 1/20 dilution 45 mJ / cm ² 0.35 μm ○ 〃 2 A1 C1 〃 1/5 dilution 40 mJ / cm ² 0.32 μm ○ 〃 3 A2 C2 60 ° C × 60 seconds 1/5 dilution 45 mJ / cm ² 0.35 μm ○ ４ 4 A2 C2 な し No dilution 40 mJ / cm ² 0.32 μm ○ 〃 5 A3 C2 70 ° C × 60 sec 1/5 dilution 65 mJ / cm ² 0.35 μm ○ ６ 6 A3 C2 な し No dilution 50 mJ / cm ² 0.31 μm ○ ──────────────────────────────────── Comparative Example 1 AX C1 100 ℃ × 60sec 1/20 Dilution 30 mJ / cm ² 0.40 μm ○ 〃 2 AX C1 〃 1/5 Dilution 25 mJ / cm ² 0.35 μm × 〃 3 AY C2 60 ° C × 60 seconds 1/5 Dilution 30 mJ / cm ² 0.40 μm ○ ４ 4 AY C2 な し undiluted 25 mJ / cm ² 0.35 μm × ５ 5 AZ C2 70 ° C × 60 seconds 1/5 dilution 40 mJ / cm ² 0.40 μm ○ ６ 6 AZ C2 な し no dilution 30 mJ / cm ² 0.35 μm × ━━━━━━━━━━━━━━━━━━━━━━━━━━

(Footnote to Table 1) Quencher C1: N-phenyldiethanolamine C2: 2,6-diisopropylaniline

Synthesis Example 10 (Synthesis of Resin A4) 2-Methyl-2-adamantyl methacrylate and α-
50: 5 methacryloyloxy-γ-butyrolactone
The mixture was charged at a molar ratio of 0 (40.0 g: 29.0 g), and methylisobutyl ketone was added in an amount of 2 times the 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 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 represented by the following formula and having a composition molar ratio of each unit of 50:50 and a weight average molecular weight of about 8,000 was obtained.

[0054]

Synthesis Example 11 (Synthesis of Resin A5) 2-methyl-2-adamantyl methacrylate, α-methacryloyloxy-γ-butyrolactone and 1-ethoxyethyl methacrylate in a 50:40:10 molar ratio (40 .0g: 23.2g: 5.4g), and methylisobutylketone, which was twice the weight of all monomers, was added to form a solution. Thereto, azobisisobutyronitrile was added as an initiator in an amount of 2 mol% based on the total amount of monomers, and about 8% at 80 ° C.
Heated for 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, it is represented by the following formula, and the composition molar ratio of each unit is 50:40:10
Thus, a copolymer having a weight average molecular weight of about 8,000 was obtained.

[0056]

Synthesis Example 12 (Synthesis of Resin A6) 2-Methyl-2-adamantyl methacrylate, α-methacryloyloxy-γ-butyrolactone and 1- (2-methylpropoxy) ethyl methacrylate were mixed in a ratio of 50:40:
The mixture was charged at a molar ratio of 10 (40.0 g: 23.2 g: 6.4 g), and methylisobutyl ketone was added in an amount of 2 times the 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 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 represented by the following formula and having a composition molar ratio of each unit of 50:40:10 and a weight average molecular weight of about 8,000 was obtained.

[0058]

Synthesis Example 13 (Synthesis of Resin A7) 2-methyl-2-adamantyl methacrylate, α-methacryloyloxy-γ-butyrolactone and tert-butyl methacrylate were mixed at a molar ratio of 50:40:10 (40.40: 10). 0
g: 23.2 g: 4.8 g), and methylisobutyl ketone was added at twice the 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 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 represented by the following formula and having a composition molar ratio of each unit of 50:40:10 and a weight average molecular weight of about 8,000 was obtained.

[0060]

Examples 7 to 10 For each example, 15 parts of the resin shown in Table 2 and 0.3 part of 4-methylphenyldiphenylsulfonium trifluoromethanesulfonate (manufactured by Midori Kagaku Co., Ltd.) as an acid generator were used. Using 0.02 parts of 2,6-diisopropylaniline as a quencher and dissolving them in 70 parts of propylene glycol monomethyl ether acetate, the solution was filtered through a fluororesin filter having a pore diameter 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 baking conditions of 215 ° C. and 60 seconds. Pre-baking after application of the resist solution was performed on a direct hot plate at 130 ° C. and 60 seconds. went.

A KrF excimer stepper [NSR “NSR” manufactured by Nikon Co., Ltd.]
The line and space pattern was exposed using 1755 EX8A ", NA = 0.45].
Post-exposure bake for 60 seconds at 20 ° C (PE
B), followed by dip development for 60 seconds with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide. The developed pattern was observed with a scanning electron microscope, and 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 0.5 μm line and space pattern becomes 1: 1.

Resolution: Displayed with the minimum size of a line and space pattern separated by the exposure amount of the effective sensitivity.

The pattern on the substrate not provided with the organic anti-reflection film was evaluated for adhesiveness, and was adhered to the substrate at an exposure amount such that the 0.5 μm line and space pattern became 1: 1. Is indicated by ○, and those that have been peeled off are indicated by x. Table 2 shows the results together with the resist composition.
Shown in

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[Table 2]

As shown in Tables 1 and 2, according to the present invention, a resist using resin A1, A2, A3, A4, A5, A6 or A7 does not peel off even when the concentration of the developing solution is high. Excellent in adhesion to a substrate. Also, the resolution has been improved, and the sensitivity is not significantly impaired. The compositions used in Examples 1 to 10 similarly give a resist pattern having excellent performance even when exposed with an ArF excimer laser exposure machine.

[0068]

Industrial Applicability The chemically amplified positive resist composition of the present invention has excellent adhesiveness to a substrate and also has excellent resist properties such as sensitivity and resolution. Therefore, this 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 (6)

[Claims] 1. A chemically amplified positive resist composition comprising a resin having a butyrolactone residue which may be substituted with alkyl, and an acid generator. 2. The composition according to claim 1, wherein the butyrolactone residue is bonded to the resin substrate by an ester bond or an ether bond. 3. The composition according to claim 1, wherein the butyrolactone residue is an α-residue of the butyrolactone. 4. The composition according to claim 1, wherein said resin has, in addition to said butyrolactone residue, a group which is cleaved by the action of an acid. 5. The composition according to claim 4, wherein the group which is cleaved by the action of an acid has an alicyclic ring. 6. The composition according to claim 4, wherein the resin has an alicyclic ring in addition to the butyrolactone residue and a group which is cleaved by the action of an acid.