JP2003255544A - Positive resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition excellent in transmittance to light of ≤170 nm wavelength and suitable particularly for F<SB>2</SB>excimer laser lithography. <P>SOLUTION: The positive resist composition comprises a resin having polymerization units of formulae (I) and (II) and insoluble or poorly soluble itself in an alkali aqueous solution but becoming soluble in an alkali aqueous solution by the action of an acid; and an acid generating agent: wherein, R<SB>1</SB>-R<SB>3</SB>represent each independently hydrogen, halogen, hydroxyl, a 1-14C alkyl, an alicyclic ring or a lactone ring; n and l represent each independently an integer of 0-4; R<SB>4</SB>and R<SB>5</SB>represent each independently hydrogen or a 1-4C alkyl; R<SB>6</SB>and R<SB>7</SB>represent 1-6C alkyl groups, provided that one or both of the alkyl groups are substituted by at least one fluorine atom; and R<SB>8</SB>represents an acid-unstable group dissociating in the presence of an acid. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a chemically amplified positive resist composition.

[0002]

2. Description of the Related Art A lithographic process using a resist composition is usually employed for fine processing of semiconductors.
In lithography, Rayleigh
As represented by the expression of the diffraction limit of h), in principle, the shorter the exposure wavelength, the higher the resolution can be. The exposure light source for lithography used for manufacturing semiconductors is a g-line with a wavelength of 436 nm, an i-line with a wavelength of 365 nm, and a wavelength of 248.
nm KrF excimer laser, Ar wavelength 193 nm
The wavelength of the F excimer laser is becoming shorter year by year, and the F ₂ excimer laser having a wavelength of 157 nm is expected as a next-generation exposure light source. For KrF excimer laser exposure and ArF excimer laser exposure, so-called chemically amplified resists that utilize the catalytic action of acid generated by exposure are often used because of their excellent sensitivity. Also, for F ₂ excimer laser exposure, there is a high possibility that a chemically amplified resist is used in terms of sensitivity.

However, the resin used in the resist for the conventional KrF excimer laser exposure or ArF excimer laser exposure (see, for example, Patent Document 1) is
It did not show sufficient transmittance for light having a wavelength of 170 nm or less, for example, F ₂ excimer laser having a wavelength of 157 nm. A low transmittance adversely affects various performances such as profile, contrast and sensitivity.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2000-137327 (pages 9 to 12)

[0004]

The object of the present invention is to
Excellent transmittance for light with a wavelength of 0 nm or less, especially F ₂
It is to provide a resist composition suitable for excimer laser lithography.

[0005]

SUMMARY OF THE INVENTION The present inventors have found that by using a resin having a polymerized unit derived from a specific monomer as a resin constituting a resist composition,
The present invention has been completed by finding that a resist having a well-balanced performance such as sensitivity and resolution can be prepared by improving the transmittance at the wavelength of the F ₂ excimer laser of m.

That is, the present invention has polymerized units represented by the general formulas (I) and (II), which are insoluble or hardly soluble in an alkaline aqueous solution, but can be dissolved in an alkaline aqueous solution by the action of an acid. The present invention relates to a positive resist composition containing a soluble resin and an acid generator. (In the formula, R ¹ , R ² , and R ³ each independently represent hydrogen, halogen, a hydroxyl group, an alkyl group having 1 to 14 carbon atoms, an alicyclic ring, or a lactone ring. It may have at least one kind of substituent selected from the group consisting of a hydroxyl group and an alicyclic ring, wherein the alicyclic ring and the lactone ring each independently represent a group consisting of a halogen, a hydroxyl group and an alkyl group. You may have at least 1 sort (s) of substituent selected, and n and l are each independently 0-4.
Represents the integer. R _4, R ₅ each independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms. R ₆ and R ₇ represent an alkyl group having 1 to 6 carbon atoms, and either or both of the alkyl groups are substituted with at least one fluorine atom. R ₈ represents an acid labile group which dissociates in the presence of an acid. )

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The positive resist composition of the present invention contains a resin having a polymerized unit represented by the above general formulas (I) and (II), and an acid generator.

In the general formulas (I) and (II), R ¹ ,
R ² and R ³ each independently represent hydrogen, halogen, a hydroxyl group, an alkyl group having 1 to 14 carbon atoms, an alicyclic ring or a lactone ring. The alkyl group may have at least one kind of substituent selected from the group consisting of halogen, hydroxyl group and alicyclic ring, and is linear, cyclic or branched. The alicyclic ring and lactone ring may each independently have at least one kind of substituent selected from the group consisting of halogen, hydroxyl group and alkyl group. n and l are
Each independently represent an integer of 0 to ₄ , and R ₄ and R ₅ each independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms. Either or both of R ₆ and R ₇ is an alkyl group having 1 to 6 carbon atoms which is substituted with at least one fluorine atom. R ₈ represents an acid labile group which dissociates in the presence of an acid.

Examples of the alkyl group having 1 to 14 carbon atoms which may be substituted with a halogen atom include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group,
Examples thereof include n-butyl group, tert-butyl group, fluoromethyl group, difluoromethyl group and trifluoromethyl group. Examples of the alicyclic ring include a cyclopentyl group and a cyclohexyl group. A hydroxymethyl group etc. can be mentioned as an alkyl group substituted by the hydroxyl group. R ₆ and R ₇ have 1 carbon atom
~ 6 alkyl groups, wherein either or both of the alkyl groups are substituted with at least one fluorine atom. The alkyl group may be linear, branched or cyclic.
1 carbon atom substituted with at least one fluorine atom
Examples of the alkyl group of ~ 6 include, for example, fluoromethyl group, difluoromethyl group, trifluoromethyl group, 2,
2,2-trifluoroethyl group, perfluoroethyl group, and the like -C _{(CF 3)} 3.

Examples of the acid labile group represented by R ₈ which dissociates in the presence of an acid include an acid labile group which dissociates in the presence of an acid and becomes soluble in an alkaline aqueous solution. Examples of the acid labile group include various known protecting groups. Examples of the acid labile group that dissociates in the presence of the acid include groups in which R ⁸ is represented by the general formula (III). (In the formula, R ⁹ and R ¹⁰ are each independently at least 1 selected from the group consisting of halogen, a hydroxyl group and an alicyclic ring.
Represents an alkyl group having 1 to 14 carbon atoms or hydrogen which may have a certain kind of substituent. R ¹¹ represents hydrogen, an alkyl group having 1 to 14 carbon atoms, an alicyclic ring, a lactone ring or an aromatic ring. The alkyl group may have at least one kind of substituent selected from the group consisting of halogen, hydroxyl group, alicyclic ring and aromatic ring. The alicyclic ring, lactone ring and aromatic ring may each independently have at least one kind of substituent selected from the group consisting of halogen, hydroxyl group and alkyl group. )
As the acid labile group dissociating in the presence of the acid, specifically, a tert-butyl group, a group in which a quaternary carbon such as a tert-butoxycarbonylmethyl group is bonded to an oxygen atom; a tetrahydro-2-pyranyl group, Tetrahydro-2-furyl group, 1
-Ethoxyethyl group, 1- (2-methylpropoxy) ethyl group, 1- (2-methoxyethoxy) ethyl group, 1-
(2-acetoxyethoxy) ethyl group, 1- [2- (1
-Adamantyloxy) ethoxy] ethyl group, 1- [2
Examples thereof include acetal type groups such as-(1-adamantanecarbonyloxy) ethoxy] ethyl group, methoxymethyl group, ethoxymethyl group, pivaloyloxymethyl group, methoxyethoxymethyl group, and benzyloxymethyl group.

Particularly, it is preferable to use an acetal type group such as a methoxymethyl group and an ethoxymethyl group because they can be easily purchased and synthesized. The acid labile group is
It will be replaced with hydrogen of the alkali-soluble group. The acid labile group is subjected to a known protecting group introduction reaction,
Alternatively, it can be easily introduced into the resin by copolymerizing an unsaturated compound having such a group as one monomer.

In the above polymerized unit (I), R ^{1 to} R
^At least one of ⁷ is a trifluoromethyl group and / or a group represented by the following general formula (IV):
It is preferable because the transmittance of vacuum ultraviolet light represented by 7 nm becomes high. In the formula, R ¹ , R ² and R ³ are the same as defined above.
R ₈ 'represents an acid labile group or hydrogen that dissociates in the presence of an acid.

The resin used in the present invention can be obtained by polymerization by a known polymerization reaction. That is,
Polymerization can be carried out by mixing a monomer capable of inducing the above-mentioned polymerized unit with a catalyst in the presence or absence of a solvent and stirring at a suitable temperature. The obtained polymer can be purified by precipitation in a suitable solvent. Examples of the resin in the present invention include resins obtained by substituting hydrogen of a hydroxyl group of a resin having a polymerized unit represented by the general formula (II) with an acid labile group which dissociates in the presence of an acid. (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R ₇ are the same as the above definition. N and l are the same as the above definition.)

The resin used in the present invention varies depending on the type of radiation for patterning exposure and the type of group cleaved by the action of an acid, but in general, a polymerized unit having a group cleaved by the action of an acid. Is preferably contained in an amount of 15 to 50 mol%.

Examples of the resin having the polymerized units of the formulas (I) and (II) include those represented by the following formulae.

[0016] Specific examples of the resin in the present invention include resins in which the polymer units represented by the general formula (I) are two or more polymer units represented by the general formula (I) in which at least R ₈ are different from each other. .

The acid generator used in the present invention may be the acid generator itself or a resist composition containing the acid generator,
There is no particular limitation as long as the acid generator decomposes to generate an acid when exposed to radiation such as light or an electron beam. 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. Examples of the acid generator include onium salt compounds, organic halogen compounds, sulfone compounds, sulfonate compounds and the like. Examples of the sulfonate compound include compounds represented by the general formula (V). (In the formula, R ¹² , R ¹³ and R ¹⁴ represent hydrogen, halogen, a hydroxyl group, an alkyl group having 1 to 14 carbon atoms and an alkoxy group. The alkyl group represents a halogen, a hydroxyl group, an alicyclic ring and an aromatic group. The alkoxy group may have at least one kind of substituent selected from the group consisting of rings, wherein the alkoxy group is at least one kind of substituent selected from the group consisting of halogen, hydroxyl group, alicyclic ring and aromatic ring. The alicyclic ring, lactone ring and aromatic ring may each independently have at least one substituent selected from the group consisting of halogen, hydroxyl group and alkyl group. R ¹⁵ represents an alkyl chain having 8 or more carbon atoms which may be substituted with halogen, may be linear or branched, and may be alicyclic.) In the compound, R ¹⁵ has 8 or more carbon atoms. All hydrogens in the alkyl chain are replaced by fluorine That it is preferable a fluorocarbon chain.

Specific examples of the acid generator in the present invention include the following compounds. Diphenyliodonium trifluoromethanesulfonate, 4
-Methoxyphenylphenyliodonium hexafluoroantimonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, bis (4-tert-butylphenyl) iodonium tetrafluoroborate, bis (4-tert-butylphenyl) iodonium perfluorobutanesulfonate, Bis (4-tert-butylphenyl) iodonium hexafluorophosphate, bis (4-tert-butylphenyl) iodonium hexafluoroantimonate, bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butyl) (Phenyl) iodonium camphorsulfonate,

Triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium trifluoromethanesulfonate, 4-methoxyphenyldiphenylsulfonium hexafluoroantimonate, 4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, p-tolyldiphenyl Sulfonium trifluoromethanesulfonate, p-
Tolyldiphenylsulfonium perfluorobutanesulfonate, p-tolyldiphenylsulfonium perfluorooctanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-tert-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-
Phenylthiophenyldiphenylsulfonium hexafluorophosphate, 4-phenylthiophenyldiphenylsulfonium hexafluoroantimonate,
1- (2-naphthoylmethyl) thioranium hexafluoroantimonate, 1- (2-naphthoylmethyl)
Thioranium 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
-Toluene sulfonate (common name benzoin tosylate), 2-benzoyl-2-hydroxy-2-phenylethyl p-toluene sulfonate (common name α-methylol benzoin tosylate), 1,2,3-benzenetriyl trismethane sulfonate, 2 , 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.

A basic compound may be added to the positive resist composition of the present invention as a quencher, and examples of the basic compound include basic nitrogen-containing organic compounds such as amines. The addition of the basic compound as a quencher can improve the performance deterioration due to the deactivation of the acid due to the leaving after the exposure, and therefore the basic compound is preferably blended. Specific examples of the basic compound include compounds represented by the following formulas.

[0025]

[0026]

Wherein R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , and R ²¹
Each independently represent hydrogen, an alkyl group, a cycloalkyl group or aryl. The alkyl group, cycloalkyl group and aryl group may each independently have at least one substituent selected from the group consisting of a hydroxyl group, an amino group and an alkoxy group having 1 to 6 carbon atoms. The amino group may be substituted with an alkyl group having 1 to 18 carbon atoms. The alkyl group preferably has about 1 to 8 carbon atoms, the cycloalkyl group preferably has about 5 to 10 carbon atoms, and the aryl group preferably has about 6 to 10 carbon atoms. A represents alkylene, carbonyl, imino, sulfide or disulfide. The alkylene preferably has about 2 to 6 carbon atoms. In addition, R ^{17 to} R
^{In 21} , any of those that can have both a linear structure and a branched structure may be used. Particularly, it is preferable to use the compound having the structure represented by the formula (VI) as a quencher from the viewpoint of improving the resolution. Specific examples include tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-trifluoromethyl-phenyltrimethylammonium hydroxide and the like. .

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 20 to 0.1% by weight based on the total solid content. When using a basic compound as a quencher, it is preferable to contain the basic compound in the range of 0.001 to 1 part by weight, and the range of 0.01 to 1 part by weight with respect to 100 parts by weight of the resin. Is more preferable. This composition also contains a sensitizer, if necessary.
A small amount of various additives such as a dissolution inhibitor, another resin, a surfactant, a stabilizer and a dye may be contained.

The resist composition of the present invention usually becomes a resist solution in a state in which each of the above components is dissolved in a solvent and is applied onto a substrate such as a silicon wafer by a conventional method such as spin coating. The solvent used here may be any solvent that dissolves each component, has an appropriate drying rate, and gives a uniform and smooth coating film after the solvent evaporates. Solvents generally used in this field are used. You can.

For example, glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate or propylene glycol monomethyl ether acetate; ethers such as diethylene glycol dimethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate or ethyl pyruvate. Examples thereof include ketones such as acetone, methyl isobutyl ketone, 2-heptanone or cyclohexanone; cyclic esters such as γ-butyrolactone. These solvents may be used alone or in combination of two or more.

The resist film coated and dried on the substrate is subjected to an exposure treatment for patterning, then a heat treatment for promoting a deprotecting group reaction, and then developed with an alkali developing solution. It The alkaline developer used here can be various alkaline aqueous solutions used in this field, but in general, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline) is used. Often used.

[0032]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Parts in the examples are by weight unless otherwise stated. The weight average molecular weight and dispersity are values determined by gel permeation chromatography using polystyrene as a standard product.

Resin Synthesis Example 1 Poly 5-norbornene-2- (2,2-ditrifluoromethyl-2-hydroxy) ethyl (hereinafter referred to as pNBHFA
There is a thing. (4) Weigh 4.3 g of silver tetrafluoroborate into the synthetic screw tube, add 45 g of 1,2-dichloroethane, and then
π-allyl palladium chlorobridge dimer 2.0g
Was added and stirred to prepare a complex. After stirring for 30 minutes, filter and filter the 5-norbornene-2- in the flask.
(2,2-ditrifluoromethyl-2-hydroxy) ethyl (obtained from Central Glass Co., Ltd.) 75 g and 1,2
-Dropwise into a mixed solution of 75 g of dichloroethane. After stirring at room temperature for 24 hours, an appropriate amount of tetrahydrofuran was added, hydrogen was blown into the solution, and the precipitated black matter was removed by filtration. The obtained filtrate was replaced with an ethyl acetate solution as a solvent, and washed with water 6 times. After the organic layer was concentrated, it was diluted with an appropriate amount of acetone, charged in heptane, and the resin was deposited. Then, the solvent was discarded by decanting, and the solid was dried under vacuum. Obtained poly-5-norbornene-2-
The crystals of (2,2-ditrifluoromethyl-2-hydroxy) ethyl (pNBHFA) weighed 60.7 g. The weight average molecular weight is about 14300 and the dispersity is 1.87.
(GPC method: polystyrene conversion).

Resin Synthesis Example 2: Synthesis Example of Resin A1 A flask was charged with 6 g of pNBHFA obtained in Synthesis Example 1, 60 g of methyl isobutyl ketone and 7.5 g of diisopropylethylamine, and methoxymethyl chloride 3.
9g was dripped and it was made to react at room temperature. 14 hours after the start of the reaction, an appropriate amount of methyl isobutyl ketone was added, and the mixture was washed 6 times with water. After the organic layer was concentrated, it was diluted with an appropriate amount of acetone and charged in a mixed liquid of 360 g of water and 240 g of methanol to precipitate a resin. After filtration, the solid was dried under vacuum. The crystals of the resin A1 obtained by partially methoxymethylating pNBHFA were 6.0 g. The methoxymethylation rate could be determined to be about 24% by a nuclear magnetic resonance ( ¹ H-NMR) spectrometer.

Resin Synthesis Example 3: Synthesis Example of Resin A2 2.5 g of pNBHFA obtained in Synthesis Example 1 was placed in a flask.
25 g of methyl isobutyl ketone and 1.8 g of diisopropylethylamine were charged, 1.1 g of ethoxymethyl chloride was added dropwise, and the mixture was reacted at room temperature. 14 hours after the start of the reaction, add an appropriate amount of methyl isobutyl ketone,
Washing with water was performed 6 times. After the organic layer was concentrated, it was diluted with an appropriate amount of acetone and charged in a mixed solution of 150 g of water and 100 g of methanol to precipitate a resin. After filtration, the solid was dried under vacuum. The crystals of the partially ethoxymethylated resin A2 of pNBHFA obtained were 2.3 g. Further, the ethoxymethylation rate could be determined to be about 20% by a nuclear magnetic resonance ( ¹ H-NMR) spectrometer.

[0036]

Resin Synthesis Example 4: Synthesis Example of Resin A3 In a flask, 6.0 g of pNBHFA obtained in Synthesis Example 1 was added.
Then, 60 g of methyl isobutyl ketone and 5.8 g of diisopropylethylamine were charged, 3.5 g of ethoxymethyl chloride was added dropwise, and the mixture was reacted at room temperature. 14 hours after the start of the reaction, add an appropriate amount of methyl isobutyl ketone,
Washing with water was performed 6 times. After the organic layer was concentrated, it was diluted with an appropriate amount of acetone and charged in a mixed liquid of 360 g of water and 240 g of methanol to precipitate a resin. After filtration, the solid was dried under vacuum. The obtained crystals of pNBHFA partially ethoxymethylated resin A3 were 5.3 g. Further, the ethoxymethylation rate could be determined to be about 25% by a nuclear magnetic resonance ( ¹ H-NMR) spectrometer.

Resin Synthesis Example 5: Synthesis Example of Resin A4 In a flask, 8.0 g of pNBHFA obtained in Synthesis Example 1 was added.
Then, 40 g of tetrahydrofuran and 0.4 g of dimethylaminopyridine were charged, di-tert-butyl dicarbonate was added, and the mixture was allowed to stand at room temperature for 6 hours. Then, an appropriate amount of methyl isobutyl ketone was added, and the mixture was washed with 5% acetic acid water twice and then ion-exchanged water 6 times. After the organic layer was concentrated, it was diluted with an appropriate amount of acetone and charged in a mixed liquid of 240 g of water and 360 g of methanol to precipitate a resin. After decanting, the solid was vacuum dried to obtain a partial tert. Of pNBHFA.
-7.7 g of butoxycarbonylated resin A8 crystals
Met. The tert-butoxycarbonylation rate was about 1 using a nuclear magnetic resonance ( ¹³ C-NMR) spectrometer.
I was able to obtain 1%. Further, in a flask, 5.0 g of resin AY obtained in Synthesis Example 10 described later, 50 g of methyl isobutyl ketone and 4.4 g of diisopropylethylamine were added.
2.3 g of methoxymethyl chloride was added dropwise, and the mixture was reacted at room temperature. 14 hours after the start of the reaction, an appropriate amount of methyl isobutyl ketone was added, and the mixture was washed 6 times with water. After concentrating the organic layer, dilute it with an appropriate amount of acetone and add water 30
It was charged in a mixed solution of 0 g and 200 g of methanol to precipitate a resin. After filtration, the solid was dried under vacuum. The crystals of the resin A4 obtained by partially methoxymethylating pNBHFA were 3.8 g. The methoxymethylation rate was about 17 using a nuclear magnetic resonance ( ¹ H-NMR) spectrometer.
I was able to ask for it.

Resin Synthesis Example 6: Synthesis Example of Resin A5 In a flask, 3.0 g of pNBHFA obtained in Synthesis Example 1 was added.
Then, 30 g of methyl isobutyl ketone and 4.2 g of diisopropylethylamine were charged, 3.4 g of 2-methoxyethoxymethyl chloride was added dropwise, and the mixture was reacted at room temperature.
After 15 hours, 1.7 g of diisopropylethylamine, 2
-Methoxyethoxymethyl chloride (1.4 g) was added, and the mixture was further stirred at room temperature for 7 hours. Then, an appropriate amount of methyl isobutyl ketone was added, and washing with water was performed 6 times. After the organic layer was concentrated, it was diluted with an appropriate amount of acetone and charged in a mixed solution of 180 g of water and 120 g of methanol to precipitate a resin. After filtration, the solid was dried under vacuum. The obtained pNB
The crystals of the HFA partially 2-methoxyethoxymethylated resin weighed 2.6 g. The 2-methoxyethoxymethylation rate could be determined to be about 23% by a nuclear magnetic resonance ( ¹ H-NMR) spectrometer.

Resin Synthesis Example 7: Synthesis Example of Resin A6 In a four-neck flask, pNBHFA3.
00 g was added and dissolved in 30.00 g of methyl isobutyl ketone. After adding 3.39 g of diisopropylethylamine, 3.34 g of benzyl chloromethyl ether was added dropwise, and the mixture was stirred at room temperature for 21 hours. After the reaction, washing with water was repeated. The organic layer was concentrated and added dropwise to n-hexane. The obtained aggregate was decanted and then dried under reduced pressure. The following resin having an average molecular weight of about 13,000 was obtained. The benzyloxymethylation rate was calculated to be 13% by NMR. This copolymer is referred to as resin A6.

Resin Synthesis Example 8: Synthesis Example of Resin A7 In a four-neck flask, pNBHFA3.
00g was added and it melt | dissolved in DMF15.00g. After adding 0.17 g of potassium iodide and 0.57 g of potassium carbonate, 0.41 g of chloromethyl pivalate was added, and the mixture was stirred at room temperature for 4 hours. Furthermore, chloromethyl pivalate 0.
41 g was added and the mixture was stirred at room temperature for 4 hours. After the reaction, methyl isobutyl ketone was added to dilute the mixture, and then washing with water was repeated.
The organic layer was concentrated and added dropwise to n-hexane. The obtained aggregate was decanted and then dried under reduced pressure. Average molecular weight about 13
000 of the following resins were obtained. The pivaloyloxymethylation rate was calculated to be 15% by NMR. This copolymer is referred to as resin A7.

Resin Synthesis Example 9: Synthesis Example of Resin AX (2-Ethyl-2-adamantyl methacrylate / 3-hydroxy-1-adamantyl methacrylate / α-methacryloyloxy-γ-butyrolactone copolymer (resin AX)
Synthesis of 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl acrylate and α-methacryloyloxy-γ-butyrolactone in a molar ratio of 2: 1: 1 (20.0 g: 8.9 g: 6.8 g) was charged, and methyl isobutyl ketone in an amount of 2 times the weight of all monomers was added to obtain a solution. Azobisisobutyronitrile as an initiator was added thereto in an amount of 2 mol% based on the total amount of the monomers, the temperature was raised to 85 ° C., and the mixture was stirred for about 5 hours. After cooling the reaction mass, pouring into a large amount of heptane to cause precipitation was repeated 3 times for purification. As a result, a copolymer having a weight average molecular weight of about 8000 was obtained with a yield of 60%. This is designated as resin AX.

Resin Synthesis Example 10: Synthesis Example of Resin AY (1) pNBHFA obtained in Synthesis Example 1 was placed in a flask.
2.5 g of tetrahydrofuran, 12.5 g of tetrahydrofuran and 0.11 g of dimethylaminopyridine were charged to prepare di-tert dicarbonate.
-Butyl 1.0 g was added and the mixture was allowed to stand at room temperature for 6 hours. Then add an appropriate amount of methyl isobutyl ketone and add 2% with 5% acetic acid in water.
It was washed 6 times with ion-exchanged water. After the organic layer was concentrated, it was diluted with an appropriate amount of acetone and charged in a mixed liquid of 125 g of water and 75 g of methanol to precipitate a resin. NBHF obtained by vacuum drying the solid after decanting
The crystals of the partially tert-butoxycarbonylated resin of A homopolymer weighed 2.6 g. Also, tert-
The butoxycarbonylation rate is measured by nuclear magnetic resonance ( ¹³ C-NM
R) With a spectrometer, it could be determined to be about 30%.

Examples and Comparative Examples 10 parts by weight of the resins shown in Table 1 were dissolved in propylene glycol monomethyl ether acetate / γ-butyrolactone = 95/5 by combining 10 parts by weight of the photo-acid generator and quencher shown in the table below. Then, the solution was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist solution.

Photoacid generator A p-tolyldiphenylsulfonium perfluorooctanesulfonate B p-tolyldiphenylsulfonium perfluorobutanesulfonate C p-tolyldiphenylsulfonium trifluoromethanesulfonate Quencher D 2,6-diisopropylaniline E tetrabutylammonium hydro Oxide F Tetrahexyl ammonium hydroxide G Tetraoctyl ammonium hydroxide H Phenyl trimethyl ammonium hydroxide I 3-trifluoromethyl-phenyl trimethyl ammonium hydroxide.

[0046]

[Table 1] Example No. Resin Photo acid generator (parts by weight) Quencher (parts by weight) Example 1 A1 A (0.2) D (0.0075) Example 2 A1 A (0.2) E (0.03) Example 3 A2 A (0.2) D (0.0075) Example 4 A3 A (0.2) D (0.0075) Example 5 A4 A (0.2) D (0.0075) Example 6 A5 A (0.2) D (0.0075) Example 7 A6 A (0.2) D (0.0075) Example 8 A7 A (0.2) D (0.0075) Example 9 A1 B (0.15) D (0.0075) Example 10 A1 C (0.11) D (0.0075) Example 11 A1 A (0.2) F (0.03) Example 12 A1 A (0.2) G (0.03) Example 13 A1 A (0.2) H (0.03) Example 14 A1 A (0.2) I (0.03) Example 15 AY A (0.2) E (0.03) Comparative Example 1 AX A (0.2) D (0.0075) Comparative Example 2 AY A (0.2) D (0.0075)

Characteristics of Sensitivity and Resolution "D" which is a composition for organic antireflection film manufactured by Brewer
UV-30J-14 "is applied and baked at 215 ° C for 60 seconds to form a 1600Å-thick organic antireflection film on a silicon wafer, and the resist solution prepared above is dried to obtain a film thickness. Was 0.19 μm. After application of the resist solution, Examples 1 to 15 and Comparative Example 2 were
Comparative Example 1 was prebaked under the conditions of 160 ° C. for 60 seconds and 130 ° C. for 60 seconds for 60 seconds. On the wafer thus formed with the resist film, an ArF excimer stepper [“NSR ArF” manufactured by Nikon Corporation, NA = 0.5) was used.
5, [sigma] = 0.6], the line and space pattern was exposed by changing the exposure amount stepwise. After exposure,
Post-exposure bake was performed at 130 ° C. for 60 seconds on a hot plate, and paddle development was further performed for 60 seconds with a 2.38 wt% tetramethylammonium hydroxide aqueous solution. The line and space pattern after development on the organic antireflection film substrate was observed with a scanning electron microscope, and the effective sensitivity and resolution were examined by the following methods, and the results are shown in Table 2.

Effective sensitivity: The line and space pattern of 0.18 μm was displayed at an exposure dose of 1: 1. Resolution: The minimum size of the line-and-space pattern separated by the exposure amount of the effective sensitivity is displayed. Profile T / B: A ratio of the length of the upper side (shown as T) to the length of the bottom side (shown as B) of the line cross section of 0.18 μm is shown. The closer to 1, the better the profile.

The composition for organic antireflection film manufactured by Brewer Co. "DUV-30J-14" was applied to coat 215
The thickness is 160 by baking at 60 ℃ for 60 seconds.
On the silicon wafer on which 0Å organic antireflection film is formed, the resist solution prepared above has a film thickness of 0.13 after drying.
It was applied to have a thickness of μm. Prebaking is performed in Examples 1 to 1.
5 and Comparative Example 2 are under the condition of 160 ° C. for 60 seconds, and Comparative Example 1
Was performed on a direct hot plate under the conditions of 130 ° C. for 60 seconds. On the wafer thus formed with the resist film, a simple F ₂ excimer laser exposure machine [“VUVES-450 obtained from Lithotec Japan Co., Ltd.]
0 "] was used and the exposure amount was changed stepwise to perform open frame exposure. After the exposure, post exposure bake (PEB) was performed at 130 ° C. for 60 seconds on the direct hot plate, and further, paddle development was performed for 60 seconds with a 2.38 wt% tetramethylammonium hydroxide aqueous solution. Visually observe the wafer after development to determine the minimum exposure amount (film removal sensitivity) at which the resist film removal occurs.
The results shown in Table 2 were obtained.

On the other hand, a magnesium fluoride wafer was coated with a solution prepared by dissolving only the resist solution and the resin prepared above in a propylene glycol monomethyl ether acetate solvent so that the film thickness after drying would be 0.1 μm.
Prebaking was performed on a direct hot plate under conditions of 60 ° C. for 60 seconds to form a resist film. The transmittance of the resist film thus formed at a wavelength of 157 nm was measured using a vacuum ultraviolet spectrometer (VUV-200 manufactured by JASCO Corporation), and the results shown in Table 2 were obtained.

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[Table 2] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example No. Effective sensitivity Resolution T / B 157 nm Transmittance 157nm Exposure sensitivity (mJ / cm ² ) (μm) (%) (mJ / cm ² ) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━ Example 1 13 0.15 0.63 64 4 Example 2 58 0.14 1.00 64 20 Example 3 12 0.16 0.77 63 3 Example 4 18 0.15 0.86 63 5 Example 5 8 0.16 1.00 62 2 Example 6 17 0.15 0.33 63 1.5 Example 7 ― ― 61 ― Example 8 ― ― 60 ― Example 9 12 0.16 0.17 61 3 Example 10 15> 0.25 Not resolved 61 3 Example 11 36 0.15 0.85 63 10 Example 12 45 0.15 0.92 65 15 Example 13 14 0.15 0.73 64 4 Example 14 14 0.15 0.92 65 4 Example 15 31 0.16 1.00 59 15 15 ──────────── ────────────────────── Comparative Example 1 19 0.15 0.93 21 7 Comparative Example 2 2 0.21 No resolution 58 0.5 0.5 ━━━━━━━━ ━━━━━━━━━━━━━━━━━━━━━━━━━━━

As is clear from Table 2, the resists of the examples show high transmittance at a wavelength of 157 nm and are excellent in performance balance. Further, in the resists of Examples, the resolution and profile are further improved by using the compound having the structure of the above formula (VI) as a quencher.

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The chemically amplified positive resist composition of the present invention has a high transmittance at a wavelength of 157 nm and an excellent performance balance. Therefore, this composition
₍₂₎ It can exhibit excellent performance as a laser resist.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ identification code FI theme code (reference) G03F 7/004 501 G03F 7/004 501 503 503A H01L 21/027 H01L 21/30 502R (72) Inventor Yamaguchi Kunshi 3-1,98 Kasugade, Konohana-ku, Osaka City Sumitomo Chemical Co., Ltd. (72) Inventor Isao Yoshida 3-1-198, Kasugade, Konohana-ku, Osaka City F-term, Sumitomo Chemical Co., Ltd. (Reference) 2H025 AA01 AA02 AB16 AC04 AC08 AD03 BE07 BE10 BG00 CB08 CB41 CB45 CC20 FA10 FA17 4J002 BK001 EV296 FD206 GP03 4J100 AR11P AR11Q BA02H BA02Q BA03P BA04H BA04Q BA05H BA06Q BBQQ10QBA10Q BA11Q BA10Q BA10Q BA11Q BA10Q BA11Q

Claims (11)

[Claims] 1. A resin having polymerized units represented by the general formulas (I) and (II), which is insoluble or hardly soluble in an alkaline aqueous solution, but becomes soluble in the alkaline aqueous solution by the action of an acid. And a positive resist composition containing an acid generator. (In the formula, R ¹ , R ² , and R ³ each independently represent hydrogen, halogen, a hydroxyl group, an alkyl group having 1 to 14 carbon atoms, an alicyclic ring, or a lactone ring. It may have at least one kind of substituent selected from the group consisting of a hydroxyl group and an alicyclic ring, wherein the alicyclic ring and the lactone ring each independently represent a group consisting of a halogen, a hydroxyl group and an alkyl group. You may have at least 1 sort (s) of substituent selected, and n and l are each independently 0-4.
Represents the integer. R _4, R ₅ each independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms. R ₆ and R ₇ represent an alkyl group having 1 to 6 carbon atoms, and either or both of the alkyl groups are substituted with at least one fluorine atom. R ₈ represents an acid labile group which dissociates in the presence of an acid. ) 2. The composition according to claim 1, wherein R ⁸ is represented by formula (III). (In the formula, R ⁹ and R ¹⁰ are each independently at least 1 selected from the group consisting of halogen, a hydroxyl group and an alicyclic ring.
Represents an alkyl group having 1 to 14 carbon atoms or hydrogen which may have a certain kind of substituent. R ¹¹ represents hydrogen, an alkyl group having 1 to 14 carbon atoms, an alicyclic ring, a lactone ring or an aromatic ring. The alkyl group may have at least one kind of substituent selected from the group consisting of halogen, hydroxyl group, alicyclic ring and aromatic ring. The alicyclic ring, lactone ring and aromatic ring may each independently have at least one kind of substituent selected from the group consisting of halogen, hydroxyl group and alkyl group. ) 3. The positive resist composition according to claim 1, wherein the polymerized unit represented by the general formula (I) is represented by the general formula (IV). (In the formula, R ¹ , R ² and R ³ are the same as defined above.
R _{8 ′} represents an acid labile group or hydrogen that dissociates in the presence of an acid. ) 4. The positive resist composition according to claim 1, further comprising an acid generator represented by formula (V). (In the formula, R ¹² , R ¹³ and R ¹⁴ represent hydrogen, halogen, a hydroxyl group, an alkyl group having 1 to 14 carbon atoms and an alkoxy group. The alkyl group represents a halogen, a hydroxyl group, an alicyclic ring and an aromatic group. The alkoxy group may have at least one kind of substituent selected from the group consisting of rings, wherein the alkoxy group is at least one kind of substituent selected from the group consisting of halogen, hydroxyl group, alicyclic ring and aromatic ring. The alicyclic ring, lactone ring and aromatic ring may each independently have at least one substituent selected from the group consisting of halogen, hydroxyl group and alkyl group. (R ¹⁵ represents an alkyl chain having 8 or more carbon atoms which may be substituted with halogen, may be linear or branched, and may be alicyclic.) 5. The composition according to claim 4, wherein R ¹⁵ is a fluorocarbon chain in which all hydrogen atoms in the alkyl chain having 8 or more carbon atoms are replaced with fluorine. 6. The resin is 80 to 99.9% by weight and the acid generator is 20 to 0.1% by weight based on the total weight of the resin and the acid generator.
The composition according to any one of claims 1 to 5, which is 7. The composition according to claim 6, which further comprises a basic compound as a quencher. 8. The composition according to claim 1, wherein the basic compound is in the range of 0.001 to 1 part by weight based on 100 parts by weight of the resin. 9. The composition according to claim 7, wherein the basic compound is a compound represented by the following formula (VI). In the formula, R ¹⁷ , R ¹⁸ , R ¹⁹ , and R ²⁰ each independently represent hydrogen, an alkyl group, a cycloalkyl group, or an aryl group. The alkyl group, cycloalkyl group or aryl group may each independently have at least one substituent selected from the group consisting of a hydroxyl group, an amino group and an alkoxy group having 1 to 6 carbon atoms. The amino group may be substituted with an alkyl group having 1 to 18 carbon atoms. Also,
The alkyl group preferably has about 1 to 8 carbon atoms, the cycloalkyl group preferably has about 5 to 10 carbon atoms, and the aryl group preferably has about 6 to 10 carbon atoms. Also, R
Any of ^{17 to} R ²⁰ may have both a linear structure and a branched structure. 10. A resin obtained by substituting hydrogen of a hydroxyl group of a resin having a polymerized unit represented by the general formula (II) with an acid labile group which dissociates in the presence of an acid. 10. The composition according to any of 9. (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R ₇ are the same as the above definition. N and l are the same as the above definition.) 11. Polymerized units represented by general formula (I) are represented by general formula (I) in which at least R ₈ are different from each other.
The composition according to any one of claims 1 to 10, which is one or more polymerized units.