JPH10288839A - Radiation sensitive resin composition and manufacture of polymer to be used for same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the radiation sensitive resin composition and capable of forming a pattern high in resolution and precision and dry etching resistance by polymerizing a specified styrene monomer in the presence of a specific radical and a radical polymerization initiator. SOLUTION: The styrene monomer represented by formula I is polymerized in the presence of a radical represented by formula II and the radical and the radical polymerization initiator to produce the polymer having the repeating units each represented by formula III. In formulae I-III, R<1> is an H atom or a methyl group; R<2> is a -OH or -O-C-(=O)-O-(CH3 )3 group or the like; each of R<3> and R<4> is, independently, a straight or branched or cycle 1-6C alkyl group; each of R<5> -R<7> is, independently, an H atom or a hydroxy or alkyl group or the like; and each of R<8> -R<11> is, independently, a 1-10C alkyl or aralkyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a radiation-sensitive resin composition and a method for producing a polymer used therein. More particularly, it relates to a radiation-sensitive resin composition which can be used as a resist suitable for ultra-fine processing using radiation such as ultraviolet rays, far ultraviolet rays, X-rays or charged particle beams, and a method for producing a polymer used therefor.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration of integrated circuits, in recent years, fine processing on the order of sub-half micron or less has been performed with good reproducibility. The development of lithography technology that can do this is underway. Typical resists conventionally used in lithography processes include a positive resist using an alkali-soluble resin such as a novolak resin and a quinonediazide-based photosensitizer, and an alkali-soluble resin such as a novolak resin and an acid such as a glycoluril resin. Negative resists that use a compound that undergoes a cross-linking reaction in the presence and a compound that generates an acid upon irradiation with radiation can be cited.However, these resists are reaching the limit in performance, and microfabrication on the order of sub-half micron order or less It is very difficult to use. That is, these negative resists and positive resists are obtained by using a mercury lamp g-line (wavelength: 436 nm), i.
In a lithography process using ultraviolet rays such as lines (wavelength 365 nm), there is a problem that a sufficient resolution cannot be achieved when a fine pattern of 0.30 μm or less is formed.

Therefore, in forming a fine pattern, a lithography process using far ultraviolet rays, X-rays or electron beams which can achieve a wider depth of focus has been vigorously studied. However, conventional resists have various problems with respect to pattern shape, sensitivity, contrast, developability, etc., with respect to far ultraviolet rays, X-rays or electron beams. That is, in the case of far ultraviolet light, the light absorption of the resist is too large, so that the lower part of the pattern is narrower than the upper part of the pattern in a negative resist, so that it is likely to have a so-called reverse tapered pattern shape, and the positive resist becomes tapered at the same time. , Sensitivity, contrast, etc. are also reduced. In addition, in the case of radiation having higher energy such as X-rays and electron beams, the sensitivity is generally more greatly reduced than in the case of far ultraviolet rays.
Irradiation of radiation may cause a phenomenon in which the solubility of the developer should be increased, but the solubility is reduced.

On the other hand, as a next-generation resist, a chemically amplified resist containing a radiation-sensitive acid generator (ie, a compound that generates an acid upon irradiation with radiation) has recently attracted attention. The catalyst has the advantage of high sensitivity to various radiations due to the catalytic action of the generated acid. As such chemically amplified resists, those showing relatively good resist performance include, for example, those using a resin having a t-butyl ester group or a t-butoxycarbonyl group (see, for example, Japanese Patent Publication No. 2-27660). ), Those using a resin having a silyl group (for example, see Japanese Patent Publication No. 3-44290), those using a resin containing an acrylic acid component (for example, JP-A-4-396).
No. 65) and those using a resin having a functional group having an acetal bond or a ketal bond (see, for example, Japanese Patent Application Laid-Open No. 4-219775). These chemically amplified resists include: It has been pointed out that each has its own problems, and that practical application involves various difficulties. That is, in a system using a resin having a t-butyl ester group or a t-butoxycarbonyl group, it is difficult to form a pattern with high resolution and high accuracy, and a system using a resin having a silyl group has a good pattern. Compared to other resists that have the ability to form but do not have silyl groups,
There is a disadvantage that it is inferior in peelability from the substrate.Furthermore, in a system using a resin containing an acrylic acid component, the adhesiveness between the resist and the silicon substrate is insufficient, and a resist using an aromatic resin is used. In comparison with, there is a problem that dry etching resistance is also low, those using a resin having a functional group having an acetal bond or ketal bond,
There is a problem that it is difficult to control the line width.

In recent years, fine processing technology using a KrF excimer laser beam having a wavelength of 248 nm as a light source has been put to practical use. However, when a conventional novolak resin is used as a raw material, the light absorption of a resist is too large, so that the pattern shape is too large. Is difficult to make into a rectangle. Therefore, resins having a polyhydroxystyrene skeleton have been widely studied as a raw material resin, but even when the above-mentioned various functional groups are introduced, the essential problem has not been solved.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a radiation-sensitive resin composition which is free from peeling failure and bonding failure, can form a pattern with high resolution and high accuracy, and has high dry etching resistance. is there. Another object of the present invention is to provide a method for advantageously producing a polymer constituting the radiation-sensitive resin composition. Still other objects and advantages of the present invention will become apparent from the following description.

[0007]

According to the present invention, the above objects and advantages of the present invention are:

[0008]

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Here, R ¹ is —H or —CH ₃ , and R ² is —OH, —OC (＝ O) —OC (CH ₃ ).
_{3, -O-C (CH 3} ) 3 or ^{-O-CH (R 3) OR} 4
And R ³ and R ⁴ independently represent a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or may be bonded to each other to form a ring. A monomer containing at least one of the styrenes
The following equation (2)

[0010]

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Here, R ⁵ , R ⁶ and R ⁷ are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an alkylcarbonyloxy group, a cyano group, a carboxyl group, an alkyloxycarbonyl group. A substituted or unsubstituted alicyclic group or a substituted or unsubstituted aromatic group, and R ⁸ ,
R ⁹ , R ¹⁰ and R ¹¹ independently of one another have 1 to 10 carbon atoms
Is polymerized in the presence of a radical represented by the following formula (3), which is an alkyl group or an aralkyl group, and a radical polymerization initiator other than the radical:

[0012]

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Here, the definitions of R ¹ and R ² are the same as in the above formula (1), and are achieved by a method for producing a polymer, which comprises producing a polymer containing a repeating unit represented by the following formula: Secondly, (i) a polymer containing the repeating unit of the formula (1) obtained by the above-mentioned production method of the present invention or a polymer obtained by subjecting the polymer to a reaction, and (ii)
This is achieved by a positive radiation-sensitive resin composition containing a radiation-sensitive acid generator that generates an acid upon irradiation with radiation. Hereinafter, the present invention will be described in detail. First, the manufacturing method of the present invention will be described. Monomer used in the method of the present invention (hereinafter referred to as monomer A)
Is represented by the above formula (1). In the formula (1), R ¹
Is -H or -CH _3. R ² is -OH, -O-
C (= O) -O-C (CH 3) 3, -O-C (CH 3) 3 or -O-CH (R ³⁾ is OR ^4, and R ³ and linear R ^4, independently of one another , Branched or cyclic carbon number 1
And 6 may represent an alkyl group or bond to each other to form a ring. Specific examples of the monomer A include the following compounds. o-hydroxystyrene, o-hydroxy-α-methylstyrene, ot-
Butoxycarbonyloxystyrene, ot-butoxycarbonyloxy-α-methylstyrene, ot-butoxystyrene, ot-butoxy-α-methylstyrene, o-methoxyethoxystyrene, o-methoxyethoxy-α-methyl Styrene, o-ethoxyethoxystyrene, o-ethoxyethoxy-α-methylstyrene, o
-Methoxy-n-butoxystyrene, o-methoxy-n
-Butoxy-α-methylstyrene, o-ethoxy-n-
Butoxystyrene, o-ethoxy-n-butoxy-α-
Methylstyrene, on-butoxyethoxystyrene,
on-butoxyethoxy-α-methylstyrene, o-
t-butoxyethoxystyrene, ot-butoxyethoxy-α-methylstyrene, o-tetrapyranyloxystyrene, o-tetrapyranyloxy-α-methylstyrene, o-tetrafuranyloxystyrene, o-tetrafura Styrenes having a substituent (R ² ) at the ortho position, such as nyloxy-α-methylstyrene:

M-hydroxystyrene, m-hydroxy-α-methylstyrene, mt-butoxycarbonyloxystyrene, mt-butoxycarbonyloxy-α
-Methylstyrene, mt-butoxystyrene, mt
-Butoxy-α-methylstyrene, m-methoxyethoxystyrene, m-methoxyethoxy-α-methylstyrene, m-ethoxyethoxystyrene, m-ethoxyethoxy-α-methylstyrene, m-methoxy-n-butoxystyrene, m -Methoxy-n-butoxy-α-methylstyrene, m-ethoxy-n-butoxystyrene, m-
Ethoxy-n-butoxy-α-methylstyrene, mn
-Butoxyethoxystyrene, mn-butoxyethoxy-α-methylstyrene, mt-butoxyethoxystyrene, mt-butoxyethoxy-α-methylstyrene, m-tetrapyranyloxystyrene, m-tetrapyranyl Styrenes having a substituent (R ² ) at the meta position, such as oxy-α-methylstyrene, m-tetrafuranyloxystyrene, m-tetrafuranyloxy-α-methylstyrene:

P-hydroxystyrene, p-hydroxy-α-methylstyrene, pt-butoxycarbonyloxystyrene, pt-butoxycarbonyloxy-α
-Methylstyrene, pt-butoxystyrene, pt
-Butoxy-α-methylstyrene, p-methoxyethoxystyrene, p-methoxyethoxy-α-methylstyrene, p-ethoxyethoxystyrene, p-ethoxyethoxy-α-methylstyrene, p-methoxy-n-butoxystyrene, p -Methoxy-n-butoxy-α-methylstyrene, p-ethoxy-n-butoxystyrene, p-
Ethoxy-n-butoxy-α-methylstyrene, pn
-Butoxyethoxystyrene, pn-butoxyethoxy-α-methylstyrene, pt-butoxyethoxystyrene, pt-butoxyethoxy-α-methylstyrene, p-tetrapyranyloxystyrene, p-tetrapyranyl Styrenes having a substituent (R ² ) at the para-position, such as oxy-α-methylstyrene, p-tetrafuranyloxystyrene, and p-tetrafuranyloxy-α-methylstyrene, can be mentioned. These monomers A
Can be used alone or in combination of two or more.

In the method of the present invention, in addition to the monomer A, another monomer copolymerizable with the monomer A (hereinafter, referred to as monomer B) can be used in combination. As the monomer B, a monomer having low solubility in an alkaline developer, that is, a monomer having no acidic substituent such as a sulfonic acid group, a carboxyl group, and a phenolic hydroxyl group, and a vinyl group-containing compound, (Meth) acryloyl group-containing compounds can be exemplified. Specific examples of such compounds are listed below.

Specific examples of the vinyl group-containing compound include aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, and chlorostyrene; heteroatom-containing aromatic vinyl compounds such as vinylpyridine; and vinyl acetate. Vinyl ester compound; methyl vinyl ketone,
Preferable examples include vinyl ketone compounds such as ethyl vinyl ketone; vinyl ether compounds such as methyl vinyl ether and ethyl vinyl ether; and heteroatom-containing alicyclic vinyl compounds such as vinyl pyrrolidone and vinyl lactam. Further, specific examples of the (meth) acryloyl group-containing compound include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
N-butyl (meth) acrylate, t- (meth) acrylate
-Butyl, (meth) acrylamide, etc., and (meth)
Acrylonitrile can be suitably indicated.

These monomers B can be used alone or in combination of two or more. The proportion of the monomer A and the monomer B is preferably 70 mol% or more, more preferably 80 mol% or more, based on the sum of the two.
The amount of the monomer B is preferably at most 30 mol%, more preferably at most 20 mol%. If the proportion of the repeating unit derived from the monomer B exceeds 30 mol% based on all the repeating units of the polymer to be produced, the alkali solubility of the polymer to be produced is too low and the polymer used when used as a resist Sensitivity tends to decrease.

The polymerization of the method of the present invention is carried out in the presence of a radical represented by the above formula (2) and a radical initiator. In the above formula (2), R ⁵ , R ⁶ and R ⁷ are the same or different and are a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an alkylcarbonyloxy group, a cyano group, a carboxyl group, an alkyloxy group. A carbonyl group, a substituted or unsubstituted alicyclic group or a substituted or unsubstituted aromatic group, and R ⁸ ,
R ⁹ , R ¹⁰ and R ¹¹ are each independently an alkyl group having 1 to 10 carbon atoms or an aralkyl group. In the definition of R ⁵ , R ⁶ and R ⁷ , the alkyl group or the alkyl moiety in the definition is preferably a linear or branched alkyl having 1 to 6 carbon atoms. Examples of the substituted or unsubstituted alicyclic group and the substituted or unsubstituted aromatic group include a cyclobutyl group,
Examples include a cyclohexyl group, a phenyl group, and a paramethylphenyl group.

Specific examples of the radical represented by the formula (2) include 2,2,6,6-tetramethylpiperidinyl-1-
Oxy radicals, 2,2,6,6-tetraethylpiperidinyl-1-oxy radical, 2,2,6,6-tetramethyl-4-hydroxypiperidinyl-1-oxy radical and the like are mentioned as preferable ones. Can be. Also,
Examples of the radical initiator used together with the radical of the formula (2) include known radical initiators.
Examples of the radical initiator include azobisisobutyronitrile, diazo compounds such as azoisovaleronitrile,
Peroxides such as hydrogen peroxide and benzoyl peroxide are particularly preferred.

The amount of the radical represented by the formula (2) is
Since it is important in determining the properties of the produced polymer, particularly the molecular weight distribution, a preferable range is a ratio in which the molar ratio of the radical initiator / the radical of the formula (2) is 10 to 0.5, and more preferably. , 5 to 1. When the molar ratio exceeds 10, the molecular weight distribution of the obtained polymer tends to be widened, and when the molar ratio is less than 0.5, the polymerization rate is remarkably reduced and the amount of the radical represented by the formula (2) is reduced. Becomes too large, which is not preferable from an industrial viewpoint. The total amount of the radical and the radical initiator of the formula (2) is preferably from 0.1 to 10 parts by weight based on 100 parts by weight of the total amount of the monomers. The polymerization temperature is usually 50
１５０150 ° C. When the polymerization temperature is set to less than 50 ° C., the polymerization reaction becomes extremely slow, and when the polymerization temperature exceeds 150 ° C., the molecular weight distribution of the obtained polymer may be widened and cause a decrease in properties, all of which are preferred. Absent.

Thus, in the method of the present invention, the above formula (3)
A polymer containing a repeating unit represented by the following formula is obtained. The repeating unit represented by the above formula (3) is derived from the monomer represented by the above formula (1). A monomer represented by the above formula (1),
That is, the monomer A can be used alone or in combination of two or more as described above, and the polymer obtained in response thereto also contains one or more units derived from the monomer A. can do. When two or more types of monomers A are used, the resulting polymer has a block copolymer structure in which each monomer A forms a polymer segment and the polymer segments are connected in a block shape, or Any structure of a random copolymer structure in which each monomer component is randomly copolymerized can be adopted.

Further, for example, after polymerizing hydroxystyrene by the polymerization method of the present invention to obtain polyhydroxystyrene,
If necessary, a method of reacting with di-t-butyl dicarbonate or an alkyl allyl ether, or polymerization of t-butoxystyrene by the polymerization method of the present invention to obtain poly-t-butoxystyrene, and then, if necessary, under acidic conditions After performing the method of the present invention, such as a method of performing a treatment to polyhydroxystyrene and then reacting with di-t-butyl dicarbonate or an alkyl allyl ether,
The obtained polymer can be further subjected to a reaction.

The resulting polymer is represented by the formula (3)
The alkali solubility can be arbitrarily controlled by the ratio of the repeating unit of For example, when two or more kinds of different R ² are combined as the repeating unit of the formula (3) in the polymer and a repeating unit having —OH as R ² is selected as one of them, the ratio of the repeating unit having —OH If you lower
The polymer has low or no alkali solubility,
When the proportion of the repeating unit having OH is increased, a polymer having high alkali solubility is obtained. The number average molecular weight in terms of polystyrene of the polymer (hereinafter referred to as “Mn”) is determined by the sensitivity,
From the viewpoint of maintaining heat resistance, developability, and resolution, preferably 1,500 to 300,000, and more preferably 3.0 to 3.0.
00 to 100,000. Further, the ratio of the weight average molecular weight of the polymer in terms of polystyrene (hereinafter, referred to as “Mw”) to Mn (hereinafter, referred to as “Mw / Mn”) is determined by the sensitivity,
From the viewpoint of maintaining heat resistance, developability and resolution, it is preferably from 1 to 5, more preferably from 1.02 to 3.95.

The above-mentioned polymer obtained by the method of the present invention is combined with a radiation-sensitive acid generator to give a positive radiation-sensitive resin composition of the present invention. Within the above range, a mixture of polymers having different copolymerization ratios of the monomer A and, if necessary, the monomer B, or a polymer having a different Mn and / or Mw / Mn within the above range. A mixed polymer obtained by mixing two or more kinds of the mixture can be used as the polymer. Even when the mixed polymer is used as the polymer, the copolymerization ratio of the monomers A and B and Mn and / or Mw / Mn of the mixed polymer are preferably within the above ranges. Hereinafter, regarding the radiation-sensitive resin composition of the present invention, first, a radiation-sensitive acid generator will be described.

Radiation-Sensitive Acid Generator The radiation-sensitive acid generator used in the present invention is a compound which generates an acid upon irradiation. Examples of the radiation-sensitive acid generator used in the present invention include an onium salt, a sulfone compound, a sulfonate compound, a sulfonimide compound, and a diazomethane compound. Examples of these radiation-sensitive acid generators are shown below.

Onium salts: Examples of onium salts include iodonium salts, sulfonium salts, phosphonium salts,
Examples thereof include diazonium salts, ammonium salts, and pyridinium salts. Specific examples of the onium salt compound include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, diphenyliodonium hexafluoroantimonate, di- (pt-butylphenyl) iodonium trifluoromethanesulfonate, (Pt-butylphenyl) iodonium camphorsulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalene sulfonate, triphenylsulfonium camphorsulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate, etc. To mention Kill.

Sulfone compound: Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds thereof. Specific examples of the sulfone compound include phenacylphenylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, and 4-trisphenacylsulfone. Sulfonic acid ester compound: Examples of the sulfonic acid ester compound include alkylsulfonic acid esters, haloalkylsulfonic acid esters, arylsulfonic acid esters, and iminosulfonates.
Specific examples of the sulfonic acid ester compound include benzoin tosylate, pyrogallol tris triflate, pyrogallol methanesulfonic acid triester, nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, α-methylol benzoin tosylate, α- Examples include methylol benzoin octane sulfonic acid ester, α-methylol benzoin trifluoromethane sulfonic acid ester, α-methylol benzoindodecyl sulfonic acid ester, and the like. Sulfonimide compound: As the sulfonimide compound, for example, the following general formula (4)

[0029]

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Here, X represents a divalent group such as an alkylene group, an arylene group, or an alkoxylene group, and R ¹² represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group, or a halogen-substituted aryl group. And the compound represented by

Specific examples of the sulfonimide compound include:
N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy)
Phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5
-Ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (tri Fluoromethylsulfonyloxy)
Naphthylimide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (camphorsulfonyloxy) succinimide, N- (camphorsulfonyl) Oxy) phthalimide, N- (camphorsulfonyloxy) diphenylmaleimide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5
-Ene-2,3-dicarboximide, N- (camphorsulfonyloxy) -7-oxabicyclo [2.2.
1] hept-5-ene-2,3-dicarboximide,
N- (camphorsulfonyloxy) naphthylimide,
N- (camphorsulfonyloxy) bicyclo [2.2.
1] heptane-5,6-oxy-2,3-dicarboximide;

N- (4-methylphenylsulfonyloxy) succinimide, N- (camphor-sulfonyloxy) naphthyldicarboximide, N- (4-methylphenylsulfonyloxy) phthalimide, N- (4-methylphenylsulfonyloxy) Diphenylmaleimide, N- (4-methylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) -7-oxabicyclo [2.2.1] Hept-5-ene-2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) naphthylimide, N- (4-
Methylphenylsulfonyloxy) bicyclo [2.2.
1] Heptane-5,6-oxy-2,3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) succinimide, N- (2-trifluoromethylphenylsulfonyloxy) phthalimide, N-
(2-trifluoromethylphenylsulfonyloxy)
Diphenylmaleimide, N- (2-trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (2
-Trifluoromethylphenylsulfonyloxy) -7
-Oxabicyclo [2.2.1] hept-5-ene-2,
3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) naphthylimide, N-
(2-trifluoromethylphenylsulfonyloxy)
Bicyclo [2.2.1] heptane-5,6-oxy-2,3
-Dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) naphthylimide, N- (4
-Fluorophenylsulfonyloxy) succinimide, N- (2-fluorophenyl) phthalimide, N-
(4-fluorophenylsulfonyloxy) diphenylmaleimide, N- (4-fluorophenylsulfonyloxy) bicyclo [2.1.1] hept-5-ene-2,3
-Dicarboximide, N- (trifluoromethylsulfonyloxy) -7-oxabicyclo [2.1.1] hept-5-ene-2,3-dicarboximide, N- (4
-Fluorophenylsulfonyloxy) bicyclo [2.
1.1] Heptane-5,6-oxy-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) naphthyldicarboximide and the like.

Diazomethane compound: As the diazomethane compound, for example, the following formula (5)

[0034]

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Here, R ¹³ and R ¹⁴ may be the same or different and each represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group and a halogen-substituted aryl group. Can be mentioned.

Specific examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, and methylsulfonyl-p.
-Toluenesulfonyldiazomethane, 1-cyclohexylsulfonyl-1- (1,1-dimethylethylsulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane and the like.

Of the above-mentioned radiation-sensitive acid generators, onium salts, sulfonic acid ester compounds and sulfonimide compounds are preferred, and in particular, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium camphorsulfonate, di- (pt-butylphenyl) ) Iodonium trifluoromethanesulfonate, di- (pt-butylphenyl) iodonium camphorsulfonate, α-methylol benzoin tosylate, α-methylol benzoin octane sulfonate, α-methylol benzoin trifluoromethane sulfonate, α-methylol benzoin Dodecylsulfonic acid ester, pyrogallol methanesulfonic acid triester, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] Hept-5-ene-2,3
-Dicarboximide, N- (camphor-sulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3
-Dicarboximide, N- (camphor-sulfonyloxy) naphthyldicarboximide and the like are preferred.

In the present invention, the radiation-sensitive acid generator is used in an amount of usually 0.1 to 20 parts by weight, particularly preferably 1 to 10 parts by weight, per 100 parts by weight of the polymer. These radiation-sensitive acid generators (hereinafter referred to as "acid generators")
Is used alone or as a mixture of two or more. If the compounding amount of the acid generator is less than 0.1 part by weight, it may be difficult to effectively cause a chemical change due to the acid catalyst generated by irradiation, whereas if it exceeds 20 parts by weight, the composition may be applied. In such a case, there is a possibility that uneven coating may occur or scum may occur during development. In the radiation-sensitive resin composition of the present invention, a dissolution controlling agent, an acid diffusion controlling agent and the like described below can be further blended and used as necessary.

The dissolution inhibitor dissolution control agent has the property of controlling the alkali solubility of the radiation-sensitive resin composition, the decomposition in the presence of an acid, for example, by hydrolysis, alkali radiation-sensitive resin composition It is a compound having an action of decreasing or eliminating the solubility control effect or an action of promoting alkali solubility of the radiation-sensitive resin composition. Examples of such a dissolution controlling agent include compounds in which an acidic functional group such as a phenolic hydroxyl group and a carboxyl group is substituted with an acid-decomposable group. The dissolution controlling agent may be a low molecular weight compound or a high molecular weight compound. Preferred examples of the dissolution controlling agent include a polyhydric phenolic compound such as bisphenol A, bisphenol F and bisphenol S or an acidic functional group of a carboxylic acid compound such as hydroxyphenylacetic acid. Examples thereof include compounds in which a group is substituted with an acid-decomposable group.

The above-mentioned acid-decomposable group-containing resin can be prepared, for example, by introducing one or more acid-decomposable groups into an alkali-soluble resin, or by polymerizing a monomer having one or more acid-decomposable groups. It can be produced by copolymerization or polycondensation or copolycondensation of a polycondensation component having one or more acid-decomposable groups. The rate of introduction of acid-decomposable groups in the acid-decomposable group-containing resin (the ratio of the number of acid-decomposable groups to the total number of acidic functional groups and acid-decomposable groups in the acid-decomposable group-containing resin) is as follows: It is preferably from 15 to 100%, more preferably from 15 to 80%, particularly preferably from 15 to 60%. Further, the Mw of the acid-decomposable group-containing resin is preferably 1.000.
0 to 150,000, more preferably 3,000 to 10
It is 0,000. These acid-decomposable group-containing resins can be used alone or in combination of two or more.
The mixing ratio of the dissolution controlling agent in the present invention is 100
It is preferably 100 parts by weight or less per part by weight. If the compounding amount of the dissolution controlling agent exceeds 100 parts by weight, the film forming properties and film strength of the composition tend to decrease. The dissolution controlling agent is
Each of the low molecular weight compound or the high molecular weight compound (that is, the resin having an acid-decomposable group) can be used alone or in combination of two or more, and the low molecular weight compound and the high molecular weight compound are used in combination. Can also.

Acid Diffusion Control Agent In the present invention, the effect of controlling the diffusion phenomenon of the acid generated from the acid generator by the irradiation of radiation in the resist film to suppress an undesired chemical reaction in the unirradiated light region, and the like. It is preferable to add an acid diffusion controller having the following formula: By using such an acid diffusion controller, the storage stability of the composition is improved, the resolution as a resist is improved, and the line width of the resist pattern can be suppressed from changing over time. It will be excellent. As the acid diffusion controller, a nitrogen-containing organic compound whose basicity is not changed by irradiation or baking is preferably used. Such nitrogen-containing organic compounds include:
For example, the following formula (6) R ¹⁵ R ¹⁶ R ¹⁷ N (6) wherein R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. (Hereinafter, referred to as “nitrogen-containing compound (I)”), a diamino compound having two nitrogen atoms in the same molecule (hereinafter, referred to as “nitrogen-containing compound (II)”), and three nitrogen atoms Examples thereof include the diamino polymer (hereinafter, referred to as "nitrogen-containing compound (III)"), the amide group-containing compound, the urea compound, and the nitrogen-containing heterocyclic compound.

Examples of the nitrogen-containing compound (I) include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine and n-decylamine; di-n-butylamine, -N
-Pentylamine, di-n-hexylamine, di-n-
Dialkylamines such as heptylamine, di-n-octylamine, di-n-nonylamine and di-n-decylamine; tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n Trialkylamines such as -hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine; aniline, N-
Examples thereof include aromatic amines such as methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, and naphthylamine.

Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane,
4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2'-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- ( 4-aminophenyl) propane, 2- (4-aminophenyl) -2-
(3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-
Methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene and the like can be mentioned.

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

Examples of the nitrogen-containing heterocyclic compound include imidazoles such as imidazole, benzimidazole, 4-methylimidazole and 4-methyl-2-phenylimidazole; pyridine, 2-methylpyridine,
Methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine,
In addition to pyridines such as N-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline, acridine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, -Methylmorpholine,
Piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like can be mentioned. Among these nitrogen-containing organic compounds, a nitrogen-containing compound (I), a nitrogen-containing heterocyclic compound and the like are preferable. Further, among the nitrogen-containing compounds (I), trialkylamines are particularly preferable, and among the nitrogen-containing heterocyclic compounds, pyridines are particularly preferable.

In the present invention, the acid diffusion controlling agents can be used alone or in combination of two or more. The amount of the acid diffusion controller used in the present invention is 10% by weight of the polymer.
Usually 5 parts by weight or less, preferably 0.00
The amount is 1 to 3 parts by weight, more preferably 0.005 to 2 parts by weight. In this case, if the amount of the acid diffusion controller exceeds 5 parts by weight, the sensitivity as a resist and the developability of an exposed portion tend to decrease. Further, the amount of the acid diffusion controlling agent used is 0.5.
If the amount is less than 001 parts by weight, the pattern shape and dimensional fidelity as a resist may be reduced depending on the process conditions.

Various Additives The radiation-sensitive resin composition of the present invention may further contain various additives such as a surfactant and a sensitizer, if necessary. The surfactant has an effect of improving the applicability and striation of the radiation-sensitive resin composition solution, the developability of the resist, and the like. Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene glycol dilaurate, and polyoxyethylene glycol dilaurate. In addition to ethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and Polyflow N
o.75, No95 (manufactured by Kyoeisha Yushi Kagaku Kogyo), F-Top EF301, EF303, EF352 (Tochem Products), Megafac F171, F172, F173 (manufactured by Dainippon Ink and Chemicals), Florad FC430, FC
431 (Sumitomo 3M), Asahi Guard AG71
0, Surflon S-382, SC-101, SC-102,
SC-103, SC-104, SC-105, SC-10
6 (made by Asahi Glass). The amount of the surfactant is usually 2 parts by weight or less per 100 parts by weight of the total solids in the radiation-sensitive resin composition.

The sensitizer absorbs radiation energy and transfers the energy to the radiation-sensitive acid generator.
It has the effect of increasing the amount of acid produced,
This has the effect of improving the sensitivity of the resist obtained using the composition of the present invention. Preferred specific examples of the sensitizer include ketones, benzenes, acetophenones, benzophenones, naphthalenes, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. The compounding amount of the sensitizer is usually 50 parts by weight or less, preferably 30 parts by weight or less based on 100 parts by weight of the total solids in the radiation-sensitive resin composition.

The addition of a dye or a pigment can reduce the effects of halation at the time of radiation irradiation, and the addition of an adhesion aid can improve the adhesion to a substrate. Further, other additives include antihalation agents such as azo compounds and amine compounds, storage stabilizers, defoamers, shape improvers and the like.

Solvent The radiation-sensitive resin composition of the present invention may be used,
The solid content is, for example, 5 to 50% by weight, preferably 20 to 50% by weight.
After being dissolved in a solvent so as to have a concentration of 40% by weight, the composition is prepared as a composition solution by filtering through a filter having a pore size of about 0.2 μm, for example.

Examples of the solvent used for preparing the composition solution include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether; Ethylene glycol monoalkyl ether acetates such as monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether Which diethylene glycol dialkyl ethers; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether; propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether Propylene glycol dialkyl ethers such as propylene glycol dibutyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, and the like. Propylene glycol monoalkyl ether acetates;

Lactic esters such as methyl lactate, ethyl lactate, n-propyl lactate, isopropyl lactate, n-butyl lactate and isobutyl lactate; methyl formate, ethyl formate, n-propyl formate, isopropyl formate, n-butyl formate;
Isobutyl formate, n-amyl formate, isoamyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, n-hexyl acetate, methyl propionate, Aliphatic carboxylic acids such as ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, isobutyl butyrate Acid esters: ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxy-2-methylpropionate (methyl β-methoxybutyrate), methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate ,
Ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate,
3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoacetate, ethyl acetoacetate, methyl pyruvate And other esters such as ethyl pyruvate;

Aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone, 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone; N-methylformamide, N, N-dimethylformamide, N-methylacetamide Amides such as N, N-dimethylacetamide and N-methylpyrrolidone; γ
-Lactones such as butyrolactone. These solvents are used alone or in combination of two or more. The amount of the solvent used in the composition solution in the present invention is usually based on 100 parts by weight of the total solids such as the polymer and the radiation-sensitive acid generator and, if necessary, the dissolution inhibitor and / or additives. 20 to 3.0
00 parts by weight, preferably 50 to 3,000 parts by weight, more preferably 100 to 2,000 parts by weight.

In forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition solution is coated with, for example, a silicon wafer or aluminum by means of spin coating, casting coating, roll coating or the like. A resist film is formed by applying the resist film on a substrate such as a wafer, and the resist film is irradiated with radiation so as to form a desired pattern. Depending on the type of radiation-sensitive acid generator used, the radiation used at this time is ultraviolet rays such as i-rays; far ultraviolet rays such as excimer lasers; X-rays such as synchrotron radiation; charged particle beams such as electron beams. Is appropriately selected and used. The radiation irradiation conditions such as the radiation dose are appropriately selected according to the composition of the radiation-sensitive resin composition, the type of additive, and the like.

When a resist pattern is formed using the radiation-sensitive resin composition of the present invention, a protective film is formed on the resist film in order to prevent the influence of basic impurities contained in the working atmosphere. It can also be provided. Further, in the present invention, in order to improve the apparent sensitivity of the resist film, it is preferable to perform baking after irradiation with radiation. The heating conditions vary depending on the composition of the radiation-sensitive resin composition, the types of additives, and the like.
00 ° C, preferably 50 to 150 ° C.

Next, a predetermined resist pattern is formed by developing with an alkali developing solution. Examples of the alkali developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine,
Triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1.8
-Diazabicyclo- [5.4.0] -7-undecene,
An alkaline aqueous solution in which an alkaline compound such as 1,5-diazabicyclo- [4.3.0] -5-nonene is dissolved in a concentration of usually 1 to 10% by weight, preferably 2 to 5% by weight is used. Is done. Further, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and a surfactant may be added to the developer. When a developer composed of an alkaline aqueous solution is used, the developer is generally washed with water after the development.

[0057]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. However, the present invention is not limited to these Examples unless it exceeds the gist thereof. In the examples, various characteristics were evaluated as follows.

Mn and Mw / Mn GPC columns manufactured by Tosoh Corporation (G2500H, G300
0H, G4000H) and a gel permeation chromatographic method using monodisperse polystyrene as a standard under the analysis conditions of a flow rate of 1.0 ml / min, an elution solvent of tetrahydrofuran, and a column temperature of 40 ° C.

Optimal radiation dose <Evaluation with KrF excimer light> The radiation-sensitive resin composition of the present invention is spin-coated on a silicon wafer and heated on a hot plate at 90 ° C. for 60 seconds (hereinafter, “prebake”). The solvent was removed to obtain a film having a thickness of 0.7 μm. Using an exposure apparatus using a KrF excimer laser beam as a light source, exposure is performed through a mask in which light-shielding portions and transmission portions are alternately arranged in the same size in a strip shape, and then heated again at 110 ° C. for 60 seconds on a hot plate. (Hereinafter referred to as “PEB”). After developing with a 2.38% by weight aqueous solution of tetrahydroammonium hydroxide, washing with water and drying, a 0.3 μm line-and-space pattern (1L1S) obtained when a resist pattern was formed on a silicon wafer was obtained. The radiation irradiation amount formed in the width of one to one was defined as the optimum radiation irradiation amount.

<Evaluation by Electron Beam> The radiation-sensitive resin composition of the present invention was spin-coated on a silicon wafer, prebaked on a hot plate at 90 ° C. for 60 seconds, and the solvent was removed to obtain a thickness of 0.2. A 7 μm film was obtained. This was irradiated with an electron beam having a beam size of 0.3 μm square while scanning using an electron beam irradiation apparatus, and then PEB was performed on a hot plate at 110 ° C. for 60 seconds. After developing using a 2.38% by weight aqueous solution of tetrahydroammonium hydroxide, washing with water and drying to form a 0.3 μm space pattern when a resist pattern is formed on a silicon wafer, The optimum radiation dose was used.

Resolution <Evaluation with KrF Excimer Light> Using masks of various dimensions, the minimum dimension of the resist pattern resolved when irradiating with an optimal radiation dose was defined as the resolution. <Evaluation with electron beam> The irradiation amount of the electron beam was fixed to the optimum irradiation amount, and the minimum size of the resist pattern that could be formed when the beam size was variously changed was defined as the resolution.

1L1 having a line width of 0.3 μm formed on a pattern-shaped silicon wafer
The dimension La on the lower side and the dimension Lb on the upper side of the square cross section of S were measured using a scanning electron microscope, and 0.9 ≦ Lb /
If the pattern satisfies La ≦ 1.1 and the pattern in the vicinity of the substrate has no scuffing or skirting, no overhang or rounding of the pattern head, the pattern shape is considered to be good. It was determined to be bad.

Example 1 First, 0.267 mol / benzoyl peroxide was added to styrene.
L and 2,2,6,6-tetramethylpiperidinyl-1
-Oxy radical (hereinafter abbreviated as TEMPO)
After dissolving 320 mol / L under degassing and reacting at 90 ° C. for 3 hours, unreacted styrene was removed under reduced pressure, and hexane / ethyl acetate = 90/10 (weight ratio) was used as a developing solvent. By separation on a pressure silica gel column, 2-benzoyloxy-1-phenylethyl-TEMPO (hereinafter referred to as BS)
-TEMPO). Next, in a 500 mL three-necked flask equipped with a mechanical stirrer, an internal thermometer, and a nitrogen inlet, 380 mg of BS-TEMPO was dissolved in 39 g of pt-butoxystyrene under a stream of dry nitrogen, and then heated to 125 ° C. For 5 hours. After polymerization, add 1 solution
After diluting with 50 mL of chloroform, the polymer was coagulated in methanol to recover the polymer. After dissolving this polymer in chloroform, the operation of coagulating again in methanol was repeated several times to completely remove unreacted monomers, and to recover the polymer overnight.
The polymer was dried at 0 ° C. under reduced pressure. The obtained polymer was white. As a result of GPC analysis, Mn was 22,800,
Mw / Mn was 1.14. This polymer is referred to as polymer (I).

Example 2 BS-TEMP was added to 35.3 g of pt-butoxystyrene.
A polymer was synthesized in the same manner as in Example 1 except that 300 mg of O was dissolved, and Mn = 25,100, Mw / M
n obtained the polymer of 1.16. This polymer was converted to polymer (I
I). Example 3 50 equipped with a mechanical stirrer, internal thermometer and nitrogen inlet
4.8 g of a polystyrene polymer (Mn = 14,000, Mw / Mn = 1.11) synthesized according to the same procedure as in Example 1 in a 0 mL three-necked flask under a stream of dry nitrogen.
Was dissolved in 41.0 g of pt-butoxystyrene, and 1
Polymerization was performed at 25 ° C. for 5 hours. After polymerization, the solution is
After dilution with mL of chloroform, the mixture was coagulated in methanol to recover a polymer. After dissolving this polymer in chloroform, the operation of coagulating again in methanol was repeated several times to completely remove unreacted monomers, and to recover overnight.
The polymer was dried under reduced pressure at ℃. The obtained polymer was white, and as a result of GPC analysis, Mn was 55,300 and Mw / M
n was 1.22. This polymer is referred to as a polymer (III).

Example 4 A pt-butoxystyrene polymer synthesized according to the procedure shown in Example 1 (Mn = 22,800, Mw / Mn = 1.
14) 100 g was dissolved in 2000 mL of 1,4-dioxane, 200 mL of trifluoroacetic acid was added, and the mixture was stirred at room temperature for 24 hours, and then coagulated in water to recover a polymer. This polymer was dissolved in 1,4-dioxane, and then coagulated in hexane to recover the polymer.
-A polymer in which a butoxy group was substituted with a hydroxyl group was obtained. The quantitative progress of the substituent of the functional group was confirmed by performing NMR analysis of the polymer before and after the reaction. This polymer is referred to as polymer (IV). Example 5 Polymer (III) obtained in Example 3 (Mn = 55,300, M
w / Mn = 1.22) and according to the same procedure as in Example 4, from two types of polymer segments, a polymer segment composed of p-hydroxystyrene repeating units and a polymer segment composed of styrene repeating units. Was obtained. This polymer is referred to as a polymer (V).

Comparative Example 1 pt-butoxystyrene was polymerized using azobisisobutyronitrile as a polymerization initiator under the condition where no radical represented by the general formula (2) of the present invention was present. The obtained polymer (Mn = 13,500, Mw / Mn = 1.48) was treated in the same manner as in Example 4 to obtain polyhydroxystyrene. As a result of GPC analysis of the obtained polyhydroxystyrene, Mn was 9,300 and Mw / Mn was 1.46.
This polymer is referred to as polymer (VI).

Example 6 12 g of the polymer (IV) obtained in Example 4 was mixed with dioxane 5
Dissolved in 0 ml. Add 5 g of triethylamine,
While stirring this mixed solution, 6.2 g of di-t-butyl dicarbonate was added, and the mixture was stirred at room temperature for 6 hours, and then oxalic acid was added to neutralize triethylamine. This solution was coagulated in a large amount of water and washed several times with pure water to obtain a polymer. The obtained polymer had Mw of 18,500 and Mw / M
n was 1.18. As a result of ¹³ C-NMR measurement, the compound had a structure in which 25% of the hydrogen atoms of the phenolic hydroxyl group were substituted with a t-butoxycarbonyl group. The above polymer, radiation-sensitive acid generator, acid diffusion controller and solvent were mixed in the proportions shown in Table 1 to form a homogeneous solution, and the pore size was adjusted to 0.1.
The solution was filtered through a 2 μm membrane filter to prepare a resist solution. The resist solution was applied on a silicon wafer by a spin coater, and prebaked at 90 ° C. for 60 seconds to form a resist film having a thickness of 0.7 μm.
After irradiating the various radiations shown in (1), PEB was performed at 110 ° C. for 60 seconds. Next, it was developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 1 minute by immersion, and washed with water for 30 seconds. The results are shown in Table 2.

Example 7 19 g of the polymer (V) obtained in Example 5 was treated with dioxane 7
Dissolved in 0 ml. 5 g of triethylamine are added,
While stirring this mixed solution, 6.2 g of di-t-butyl dicarbonate was added, and the mixture was stirred at room temperature for 6 hours, and then oxalic acid was added to neutralize triethylamine. This solution was coagulated in a large amount of water and washed several times with pure water to obtain a polymer. The obtained polymer had Mw of 47,800 and Mw / M
n was 1.26. As a result of ¹³ C-NMR measurement, the compound had a structure in which 25% of the hydrogen atoms of the phenolic hydroxyl group were substituted with a t-butoxycarbonyl group. A resist solution was prepared using the above polymer in the same manner as in Example 6, and its performance was evaluated in the same manner as in Example 6. The results are shown in Table 2.

Example 8 12 g of the polymer (IV) obtained in Example 4 was treated with dioxane 5
After dissolving in 0 ml, bubbling was performed with nitrogen for 30 minutes. To this solution, 3 g of ethyl vinyl ether and 0.5 g of pyridinium p-toluenesulfonate as a catalyst were added and reacted for 12 hours. The reaction solution was added dropwise to a 1% by weight aqueous ammonia solution to precipitate a polymer, and the polymer was dried overnight in a vacuum dryer at 50 ° C. to obtain a polymer. The obtained polymer had Mw of 18,900 and Mw / M
n was 1.18, and as a result of ¹³ C-NMR measurement, the compound had a structure in which 35% of the hydrogen atoms of a phenolic hydroxyl group were substituted with a 1-ethoxyethyl group. A resist solution was prepared using the above polymer in the same manner as in Example 6, and its performance was evaluated in the same manner as in Example 6. The results are shown in Table 2.

Example 9 19 g of the polymer (V) obtained in Example 5 was treated with dioxane 5
After dissolving in 0 ml, bubbling was performed with nitrogen for 30 minutes. To this solution, 3 g of ethyl vinyl ether and 0.5 g of pyridinium p-toluenesulfonate as a catalyst were added and reacted for 12 hours. The reaction solution was added dropwise to a 1% by weight aqueous ammonia solution to precipitate a polymer, and the polymer was dried overnight in a vacuum dryer at 50 ° C. to obtain a polymer. The obtained polymer had Mw of 47,200 and Mw / M
n was 1.24, and as a result of ¹³ C-NMR measurement, the compound had a structure in which 35.5% of hydrogen atoms of a phenolic hydroxyl group were substituted with a 1-ethoxyethyl group. A resist solution was prepared using the above polymer in the same manner as in Example 6, and its performance was evaluated in the same manner as in Example 6. The results are shown in Table 2.

Example 10 After 17.6 g of the polymer (II) obtained in Example 2 was dissolved in 50 ml of dioxane, 5 g of a 10% aqueous sulfuric acid solution was added to the solution and reacted at 50 ° C. for 3 hours. The reaction solution was added dropwise to a 1% by weight aqueous ammonia solution to precipitate a polymer, and the polymer was dried overnight in a vacuum dryer at 50 ° C. to obtain a polymer. The resulting polymer had a Mw of 19,
500, Mw / Mn is 1.14, and as a result of ¹³ C-NMR measurement, 27% of hydrogen atoms of the phenolic hydroxyl group are t
-Having a structure substituted with a butyl group. A resist solution was prepared using the above polymer in the same manner as in Example 6, and its performance was evaluated in the same manner as in Example 6. The results are shown in Table 2.

Example 11 6 g of p-hydroxystyrene, 2.1 g of styrene and 6.6 g of pt-butoxycarbonyloxystyrene were dissolved in 50 g of tetrahydrofuran, and 3.5 g of BS-TEMPO obtained in Example 1 was dissolved. In addition, polymerization was performed at 80 ° C. for 7 hours. After the polymerization, the solution was added dropwise to 500 g of water with stirring to coagulate. The operation of dissolving this polymer in methanol and coagulating it again in water was repeated several times to completely remove unreacted monomers, and the polymer was dried overnight at 50 ° C. under reduced pressure. The obtained polymer was white. As a result of GPC analysis, Mn was 18,500 and Mw / Mn was 1.17. As a result of ¹³ C-NMR measurement, p-hydroxystyrene, styrene and pt-butoxycarbonyloxystyrene were 51:20: It was a structure copolymerized at 29 (molar ratio). A resist solution was prepared using the above polymer in the same manner as in Example 6, and its performance was evaluated in the same manner as in Example 6. The results are shown in Table 2.

Comparative Example 2 12 g of the polymer (VI) obtained in Comparative Example 1 and 5 g of triethylamine were dissolved in 50 ml of dioxane. While stirring this mixed solution, 6.2 g of di-t-butyl dicarbonate was added, and the mixture was stirred at room temperature for 6 hours, and then oxalic acid was added to neutralize triethylamine. This solution was coagulated in a large amount of water and washed several times with pure water to obtain a white polymer. The obtained polymer had Mw of 11,500 and Mw / M
n was 1.51, and as a result of ¹³ C-NMR measurement, the compound had a structure in which 25% of hydrogen atoms of a phenolic hydroxyl group were substituted with a t-butoxycarbonyl group. A resist solution was prepared using the above polymer in the same manner as in Example 6, and its performance was evaluated in the same manner as in Example 6. The results are shown in Table 2.

Comparative Example 3 12 g of the polymer (VI) obtained in Comparative Example 1 was diluted with dioxane 5
After dissolving in 0 ml, bubbling was performed with nitrogen for 30 minutes. To this solution, 3 g of ethyl vinyl ether and 0.5 g of pyridinium p-toluenesulfonate as a catalyst were added and reacted for 12 hours. The reaction solution was added dropwise to a 1% by weight aqueous ammonia solution to precipitate a polymer, and the polymer was dried overnight in a vacuum dryer at 50 ° C. to obtain a polymer. The obtained polymer had Mw of 11,100 and Mw / M
n was 1.50, and as a result of ¹³ C-NMR measurement, the compound had a structure in which 35% of hydrogen atoms of a phenolic hydroxyl group were substituted with a 1-ethoxyethyl group. A resist solution was prepared using the above polymer in the same manner as in Example 6, and its performance was evaluated in the same manner as in Example 6. The results are shown in Table 2.

[0075]

[Table 1]

The abbreviations of the acid generator and the solvent in Table 1 correspond to the following. Radiation-sensitive acid generator P1: triphenylsulfonium trifluoromethanesulfonate P2: di- (pt-butylphenyl) iodonium trifluoromethanesulfonate P3: di- (pt-butylphenyl) iodonium camphorsulfonate

Solvent EL: Ethyl lactate EEP: Ethyl 3-ethoxypropionate MMP: Methyl 3-methoxypropionate PGMEA: Propylene glycol monomethyl ether acetate BA: Butyl acetate Acid diffusion controller Q1: Tri-n-octylamine Q2: Nicotine Amide

[0078]

[Table 2]

[0079]

The positive-type radiation-sensitive resin composition of the present invention is free from volume shrinkage, poor peeling and poor bonding, can form a pattern with high resolution and high accuracy, and has excellent dry etching resistance. Furthermore, the positive-type radiation-sensitive resin composition of the present invention is effective in responding to various kinds of radiation, has excellent lithography process stability, and has a small dimensional difference between the upper and lower portions of the pattern, particularly in the formation of a fine pattern, and has a rectangular shape. Has an excellent advantage of being able to form a pattern.
Furthermore, the positive-type radiation-sensitive resin composition of the present invention is excellent in pattern shape, sensitivity, contrast, etc., particularly for far ultraviolet rays, X-rays or electron beams, and it is expected that further miniaturization will progress in the future. It is extremely useful as a resist for manufacturing semiconductor devices.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 16, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 2

[Correction method] Change

[Correction contents]

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G03F 7/004 503 G03F 7/004 503 7/031 7/031 H01L 21/027 H01L 21/30 502R (72) Inventor Takeshi Fukuda Gogasho, Uji City, Kyoto Prefecture

Claims (2)

[Claims] [Claim 1] The following formula (1) Here, R ¹ is —H or —CH ₃ , and R ² is —O
H, -O-C (= O ) -O-C (CH 3) 3, -O-C
(CH ₃ ) ₃ or —O—CH (R ³ ) OR ⁴ , and R ³ and R ⁴ independently represent a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms. Alternatively, a monomer containing at least one styrene represented by the following formula (2), which may be bonded to each other to form a ring, is synthesized by the following formula (2): Here, R ⁵ , R ⁶ and R ⁷ are the same or different, and represent a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group,
Alkoxyalkyl group, alkylcarbonyloxy group,
A cyano group, a carboxyl group, an alkyloxycarbonyl group, a substituted or unsubstituted alicyclic group or a substituted or unsubstituted aromatic group, and R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ are each independently a carbon atom The compound is polymerized in the presence of a radical represented by the following formula (3), which is an alkyl group or an aralkyl group represented by the formulas 1 to 10, and a radical polymerization initiator other than the radical. Here, the definition of R ¹ and R ² is the same as in the above formula (1), and a polymer containing a repeating unit represented by the following formula is produced. 2. A polymer containing the repeating unit of the formula (1) obtained by the method according to claim 1 or a polymer obtained by subjecting the polymer to a reaction, and (ii) radiation. A positive-type radiation-sensitive resin composition, comprising a radiation-sensitive acid generator that generates an acid upon irradiation with water.