JP2003321521A - Copolymer having alcoholic hydroxy group and aromatic ring in the same recurring unit, and having leaving group by proton - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copolymer exhibiting a high-level characteristics such as change in solubility in an alkaline aqueous solution before and after treatment with a free proton, adhesiveness to a substrate, developability, chemical resistance and etching resistance, suitably applicable to various applications and having a leaving group by a proton. <P>SOLUTION: The copolymer has not only an alcoholic hydroxy group and an aromatic ring, but also a leaving group by a proton. The copolymer having the leaving group by the proton contains a repeating unit having both of the alcoholic hydroxy group and the aromatic ring as an essential component. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a copolymer having a proton-eliminating group.

[0002]

2. Description of the Related Art A copolymer having a leaving group by a proton has a group which can be eliminated by the action of a free proton and exchanged for a hydrogen atom, and such a group is exchanged for a hydrogen atom. And has a property that characteristics such as solubility in an alkaline aqueous solution change. When such a copolymer is allowed to coexist with an acid catalyst serving as a proton donor and free radicals are generated from the acid catalyst by irradiating or heating with light, plasma, radiation, etc., before and after irradiation and heating. As a result, properties such as solubility in an alkaline aqueous solution change significantly. By utilizing such characteristics, it can be applied to various applications in the chemical industry, such as photolithography materials and low-shrinkage materials that utilize the volume expansion of olefins generated by the action of acid catalysts. .

In such a copolymer having a leaving group by a proton, the adhesion to various substrates, the ability of the free proton to inhibit dissolution in an alkali aqueous solution before treatment, and the solubility in an alkali aqueous solution after treatment. Therefore, it is desired that the developability such as the contrast between the developing solution-dissolved portion and the non-dissolved portion can be sufficiently enhanced when the material is used as a photolithography material due to its excellent balance. For example, it is known that substrate adhesion and developability can be improved by introducing a hydroxyl group into the polymer. Regarding this point, Japanese Patent Laid-Open No. 2000-
Japanese Patent No. 275843 discloses a chemically amplified positive resist composition containing a copolymer obtained by polymerizing 2-hydroxyethyl methacrylate, and by introducing a hydroxyl group into the copolymer, adhesion to a substrate is ensured, and It is disclosed that the resolution and dry etching resistance of the resist are improved. However, since the hydroxyl group is introduced into the side chain of the copolymer, there is room for improvement to greatly change the properties of the resist and further improve the substrate adhesion and developability.

Japanese Patent Laid-Open No. 2000-206694 discloses that
Regarding the photosensitive resin having a methylol group in the main chain, α-
Disclosed is a negative resist composition capable of being alkali-developed by containing a polymer having a (hydroxyalkyl) acrylic acid alkyl ester. However, since this photosensitive resin does not have a benzene ring in the copolymer, it has poor chemical resistance and etching resistance when used as a resist resin, for example. There was room for

Japanese Patent Laid-Open No. 2000-131847 discloses that
Regarding a resist composition obtained by copolymerizing hydroxymethyl acrylate, a copolymer obtained by essentially polymerizing a monomer having a hydroxymethyl group and a leaving group containing a t-butyl group, It is disclosed that it has excellent sensitivity and resist pattern shape, and has substrate adhesion and dry etching resistance. As other copolymerizable components, styrene, hydroxystyrene, 4-t-butoxystyrene and the like are listed. However, such a resist composition is
Although it is suitable and excellent for resists, when an aromatic ring represented by a benzene ring, which is excellent in chemical resistance and etching resistance, is introduced into the copolymer, the benzene ring emits an ArF excimer laser (wavelength 193 nm). Since it absorbs, that is, becomes opaque, and only the surface portion of the film can be exposed to light, the copolymer containing an aromatic ring can be prepared by setting the monomer in the copolymerization component and the ratio thereof. There was room for improvement in terms of all properties such as adhesion, developability, chemical resistance, and etching resistance.

[0006]

In view of the above, the present invention has characteristics such as change in solubility in an alkaline aqueous solution before and after treatment with free protons, substrate adhesion, developability, chemical resistance and etching resistance. It is an object of the present invention to provide a copolymer having a leaving group by a proton, which is exhibited at a high level and can be suitably applied to various uses.

[0007]

Means for Solving the Problems As a result of various studies on the copolymer having a leaving group by proton, the present inventors have found that, for example, when the copolymer is used as a resist material such as a photosensitive resin. , Focusing on the fact that the compatibility of the copolymer with water is important for forming a film and developing with an alkaline aqueous solution, and introduction of a hydroxyl group into the copolymer is effective for that, and among them, an alcoholic hydroxyl group is preferable. It was found that the properties of the copolymer can be greatly changed by introducing it. This improves the familiarity of the copolymer with a highly polar developer such as an aqueous developer, and the developer is well penetrated into the recesses during the development of fine irregularities to improve the resolution. It has been found that the adhesion is also improved.

In addition to introducing an alcoholic hydroxyl group into the copolymer, introducing an aromatic ring, particularly a benzene ring, provides excellent chemical resistance, etching resistance, etc. when used for resist materials, for example. However, on the other hand, focusing on the fact that the hydrophobicity becomes strong and the familiarity of the developing solution becomes poor, and by having an aromatic ring in the same repeating unit as the repeating unit having an alcoholic hydroxyl group, that is, alcohol A repeating unit having both a hydroxyl group and an aromatic ring is essential, and when an alcoholic hydroxyl group and an aromatic ring are introduced at positions close to each other in the polymer, the chemical resistance is improved while eliminating the disadvantage of the increased hydrophobicity. Excellent in resistance, etching resistance, etc., and exhibits high levels of substrate adhesion, developability, chemical resistance and etching resistance. Is then contemplated that can be admirably solved the above problems, it is the present invention has been completed.

That is, the present invention is a copolymer having an alcoholic hydroxyl group and an aromatic ring and having a leaving group by a proton, wherein the copolymer having a leaving group by a proton is It is a copolymer having a leaving group by a proton which essentially includes a repeating unit having both an alcoholic hydroxyl group and an aromatic ring. As described above, the proton-releasable group-containing copolymer of the present invention is a proton-releasable group having an alcoholic hydroxyl group and an aromatic ring in the same repeating unit. The present invention is described in detail below.

The copolymer having a proton-eliminating group of the present invention has both an alcoholic hydroxyl group and an aromatic ring and also has a proton-eliminating group.
The alcoholic hydroxyl group is preferably bonded to the main chain through 1 to 3 atoms, and more preferably bonded to the main chain through 1 to 2 atoms. More preferably, it is an alcoholic hydroxyl group bonded to the main chain via one carbon atom. The aromatic ring may or may not have a substituent, and the carbon number is not particularly limited, but a benzene ring, a naphthalene ring and an anthracene ring are preferable, and a benzene ring or a naphthalene ring is preferable. More preferably, a benzene ring is most preferable.

In the present invention, the copolymer has a repeating unit, and the repeating unit has an alcoholic hydroxyl group, an aromatic ring and a group capable of leaving by a proton. When the repeating unit having both and is essential, the action and effect of the present invention can be exhibited. In the repeating unit having both an alcoholic hydroxyl group and an aromatic ring, one or more alcoholic hydroxyl groups and one aromatic ring are in the same repeating unit, and the alcoholic hydroxyl group and the aromatic ring in the copolymer are present. It is preferable that all or part of the ring has such a form. Further, as described above, the alcoholic hydroxyl group is preferably located near the main chain rather than the side chain. However, if the hydroxyl group is directly bonded to the main chain like polyvinyl alcohol, the rotational freedom of the main chain will decrease and the interaction between polymer molecules will become too strong, resulting in a decrease in flexibility. In addition, since the vinyl alcohol monomer is extremely unstable, an operation of hydrolyzing the copolymer of the vinyl ester monomer is required in the method of producing the copolymer, and the operation becomes complicated. The main chain means a part of a chain formed by bonding repeating units (monomer units).

The proton-eliminating group may be present at any site of the copolymer. The leaving group by a proton means a group which is eliminated by the action of a free proton and is exchanged for a hydrogen atom. The conditions at this time are not particularly limited. In addition, in order to give a free proton to the copolymer, an acid catalyst serving as a proton donor is allowed to coexist with the copolymer, and the free proton is released from the acid catalyst by irradiating or heating with light, plasma, radiation or the like. Can be performed by generating Examples of such an acid catalyst include organic sulfonic acids such as onium salts, sulfone compounds, sulfonic acid ester compounds, sulfonimide compounds, diazomethane compounds, p-toluenesulfonic acid, benzenesulfonic acid, and trifluoromethanesulfonic acid; hydrochloric acid, sulfuric acid, Nitric acid or the like is preferable. These may be used alone or in combination of two or more.

The preferred form of the copolymer having a leaving group by a proton of the present invention is (I) a repeating unit (A) and a repeating unit (B1) represented by the following general formula (1).
Or a form in which the repeating unit (A) and the repeating unit (B1) and the repeating unit (C) and / or the repeating unit (D) are essential, (II) represented by the following general formula (2) The repeating unit (A) and the repeating unit (B2) are essential, or the repeating unit (A) and the repeating unit (B2) and the repeating unit (C)
And / or a repeating unit (D) is essential, (III) The repeating unit (A) and the repeating unit (B3) represented by the following general formula (3) are essential.
Alternatively, a form in which the repeating unit (A) and the repeating unit (B3) and the repeating unit (C) and / or the repeating unit (D) are essential, and (IV) in the following general formulas (1) to (3) The repeating unit (A) represented and at least two repeating units of the repeating units (B1), (B2) and (B3) are essential, or the repeating unit (A) and the repeating unit (B1 ), (B2)
And at least two repeating units of (B3),
This is a form in which the repeating units (C) and / or (D) are essential.

[0014]

[Chemical 4]

[0015]

[Chemical 5]

[0016]

[Chemical 6]

In the above formulas (1) to (3), R¹, R^Four, R⁶
And R⁹Are the same or different and are a hydrogen atom or a methyl group.
Represents R², R⁸And R^TenIs a group having a benzene ring
Represent R ³And R⁷Are the same or different, substituted or
Represents a substituted alkyl group. R^FiveIs a leaving group by a proton
Represents a, b1, b2, b3, c and d are respectively
Repeating units (A), (B1), and (B) in the copolymer
2) represents the mole fraction of (B3), (C) and (D).

The repeating unit (B) which the copolymer having a leaving group by a proton of the present invention preferably and essentially has
1), repeating unit (B2) and repeating unit (B3)
Is a repeating unit having both an alcoholic hydroxyl group and an aromatic ring. When at least one repeating unit selected from the group consisting of these repeating units (B1), repeating units (B2) and repeating units (B3) is a repeating unit (B), it has the above-mentioned proton-eliminating group. The copolymer essentially comprises the repeating unit (A) and the repeating unit (B), or the repeating unit (A) and the repeating unit (B) and the repeating unit (C).
And / or the repeating unit (D) is essential. At this time, the repeating unit (B
The sum of the mole fractions of 1), (B2) and (B3), that is, the sum of b1, b2 and b3 is b.

Such a copolymer having a leaving group by a proton has a form in which the repeating unit (A) and the repeating unit (B) are essential, the repeating unit (A), the repeating unit (B) and the repeating unit. The form in which the unit (C) is essential, the form in which the repeating unit (A), the repeating unit (B), and the repeating unit (D) are essential, and the repeating unit (A), the repeating unit (B), and the repeating unit ( C)
And a form in which the repeating unit (D) is essential. These repeating units may be the same or different. Further, among the above-mentioned forms, the repeating unit (A), the repeating unit (B), and the repeating unit (C)
In addition, the form in which the repeating unit (D) is essential has a large change in the solubility in an alkaline aqueous solution before and after the treatment with free protons, and further improves the adhesiveness to various substrates and the developability, and further This is a preferable form because it can exhibit chemical resistance and etching resistance. Moreover, examples of the addition form of these repeating units include a random form, a block form, and an alternating form, but a random form is preferable.

In the copolymer of the present invention, the adhesion to various substrates is expressed mainly by the repeating unit (A) and the repeating unit (B). Further, the dissolution inhibiting property before treatment with free protons is expressed by the repeating unit (C) and the repeating unit (D), which are the repeating units having a leaving group by protons. In some cases, D) does not have a leaving group by a proton, and it is considered that the contribution of the repeating unit (C) is mainly large. Further, the solubility in the alkaline aqueous solution after the treatment is exhibited by neutralizing the acidic phenolic hydroxyl group of the repeating unit (A) and imparting hydrophilicity by the alcoholic hydroxyl group of the repeating unit (B). It will be. Furthermore, chemical resistance and etching resistance are exhibited by the repeating unit (A), the repeating unit (B) and the repeating unit (C). It is considered that the contribution of the repeating unit (B), which has an aromatic ring having no reactive substituent due to, is mainly large. In the present invention, the effects of these repeating units are synergistically exhibited, and all of the above-mentioned respective properties of the copolymer are improved, and the repeating unit (A), repeating unit (B), repeating unit Only by making (C) and the repeating unit (D) essential, properties such as change in solubility in an alkaline aqueous solution before and after treatment with free protons, substrate adhesion, developability, chemical resistance and etching resistance are high. It is demonstrated at a level and can be suitably applied to various uses.

In the copolymer having a leaving group by a proton of the present invention, in the general formulas (1) to (3), a, b, c and d in the abundance of repeating units are a.
Is 45 to 90 mol%, and b, that is, b1 and b2
And b3 are 5 to 50 mol%, and d is 0 to
30 mol%, and a and c are 0.2 ≦ a / (a +
It is preferable that c) ≦ 0.95 is satisfied. This allows
The effects of the present invention will be fully exhibited. More preferably, a is 50 to 90 mol%, b is 5 to 30 mol%, d is 0 to 20 mol%, and a and c are 0.5 ≦ a / (a
+ C) ≦ 0.95 is satisfied. In addition, regarding the mole fraction of each repeating unit, the total of a, b, c and d in the repeating units constituting the copolymer is 100 mol%.

When the repeating unit (A) and the repeating unit (B) are essential and the repeating unit (C) and the repeating unit (D) are not contained in the copolymer having a leaving group by a proton of the present invention, Is 50 to 90 mol% of a, b is 5 to 50 mol%, and the repeating unit (B)
Preferably contains a repeating unit (B1), and R ³ in the repeating unit (B1) is preferably a proton-eliminating group. When the repeating unit (A), the repeating unit (B) and the repeating unit (C) are essential and the repeating unit (D) is not contained, a is 45 to 90 mol% and b is 5 to 50. It is preferable that the mol%, a and c satisfy 0.2 ≦ a / (a + c) ≦ 0.95.

Examples of the leaving group by a proton in the above general formulas (1) to (3) include branched alkyl groups such as t-butyl group and isopropyl group; cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group. Cycloalkyl groups whose alicyclic skeletons are represented by the general formula C _n H _2n (n is an integer of 3 or more); 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 1-methylcyclopentyl group, 1- A group in which one or more hydrogen atoms of a cycloalkyl group such as an ethylcyclopentyl group are substituted with a linear or branched alkyl group; spiroheptane or spiro having a bridged hydrocarbon introduced into the cycloalkyl group Group formed from a compound having a spiro ring such as octane; tetrahydropyranyl group, tetrahydrofuranyl group, 3-oxocyclohexyl Group, a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 1-ethoxyethyl group, a 1-butoxyethyl group, a t-butoxycarbonyl group, a trimethylsilyl group, a triethylsilyl group and other functional groups having a hetero atom; isobornyl Group, adamantyl group, 1-methyladamantyl group, 1-ethyladamantyl group, norbornyl ring, bornene ring, menthyl ring, menthane ring, camphor ring, isocamphor ring, sesquiterpene ring, sandton ring, diterpene ring, triterpene ring, Tujan, Sabinen, Tujong, Karan, Karen,
Substituents having a terpene ring formed from compounds such as pinane, norpinane, bornane, camphene and tricyclene; cholesteric rings, bile acids, steroid skeletons such as digitoids and steroid saponins, and groups formed from polycyclic compounds Is preferred. These are hydroxyl groups,
It may be substituted with a carboxyl group, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a carboxyalkyl group or the like.

R ⁵ in the above general formulas (1) to (3)
Of these, among the proton-eliminating groups exemplified above, a t-butyl group, a t-butoxycarbonyl group, a tetrahydropyranyl group or a trimethylsilyl group is preferable. As a result, it becomes possible to more sufficiently exert the effects of the present invention. Further, in the copolymer of the present invention, the hydrogen atom of the hydrocarbon as the skeleton of the copolymer may be other groups within a range not deteriorating physical properties such as desorption by free protons and dissolution rate in alkaline water. It may be substituted. The same applies to the aromatic ring introduced into the copolymer, which may be substituted with a substituent other than a hydrogen atom.

Preferred examples of the other substituents include organic groups such as alkyl groups (ethyl group, t-butyl group, etc.); alkoxyl groups; carboxyl groups; hydroxyl groups; amino groups; sulfone groups and halogen elements. Further, the other substituents may have a structure such as a carboxylate, an ammonium salt, a quaternary ammonium salt, and a metal salt.

The group having a benzene ring in the above general formulas (1) to (3) may or may not have a substituent, and the number of carbon atoms is not particularly limited. , A naphthalene ring and an anthelan ring are preferable, and a benzene ring and a naphthalene ring are more preferable. More preferably, it is a benzene ring. That is, in the general formulas (1) to (3), R ² , R ⁸ and R ¹⁰ are preferably a phenyl group or a benzyl group.

Examples of the substituted or unsubstituted alkyl group in the above general formulas (1) to (3) include linear alkyl groups such as methyl group and ethyl group; branched alkyl groups such as t-butyl group and isopropyl group. A cycloalkyl group in which an alicyclic skeleton such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, or a cycloheptyl group is represented by the general formula C _n H _2n (n is an integer of 3 or more); 1-methylcyclohexyl group, 1 −
A group in which one or more hydrogen atoms of a cycloalkyl group such as an ethylcyclohexyl group, a 1-methylcyclopentyl group and a 1-ethylcyclopentyl group are substituted with a linear or branched alkyl group is preferable. . These may be substituted with a hydroxyl group, a carboxyl group, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a carboxyalkyl group or the like.

Among the substituted or unsubstituted alkyl groups exemplified above, a group capable of leaving by a proton is preferable, and a group in which a carbon atom bonded to an oxygen atom is a tertiary carbon atom, that is, a general formula (1) ) To (3), R ³
And R ⁷ is a t-butyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-methyladamantyl group, 1-ethyladamantyl group or the like. It is particularly preferable that R ⁷ is a group capable of leaving by a proton.

The proton-releasable group-containing copolymer of the present invention includes a copolymer represented by the following general formula (4), a copolymer represented by the following general formula (5), and the following general formula: A copolymer represented by the formula (6) is a more preferable form. The following general formula (4) is the same as the above general formula (1):
R ¹ , R ⁴ and R ⁶ are hydrogen atoms, R ² is a phenyl group, R ³ is a methyl group, R ⁵ and R ⁷ are t-butyl groups, and benzene is a repeating unit (A) and a repeating unit (C). are those substituents which have the ring is in the para position, the following general formula (5), in the above-mentioned general formula (2), R ^1, R ⁴ and R
⁶ is a hydrogen atom, R ⁸ is a benzyl group, R ⁵ and R ⁷ are t-butyl groups, and the substituents on the benzene ring of the repeating units (A) and (C) are in the para position. The following general formula (6) is a repeating unit of the above general formula (3), wherein R ¹ , R ⁴ and R ⁶ are hydrogen atoms, R ¹⁰ is a phenyl group, R ⁵ and R ⁷ are t-butyl groups. The substituents on the benzene ring of (A) and the repeating unit (C) are in the para position.

[0030]

[Chemical 7]

Where a, b1, b2, b3, c and d
Is the same as above.

The weight average molecular weight (Mw) of the copolymer having a proton-eliminating group of the present invention is preferably 2,000 or more, and more preferably 50,000 or less. If it is less than 2,000, the heat resistance may be poor, and if it exceeds 50,000, the difference in solubility change in the alkaline aqueous solution before and after the treatment with free protons is not sufficient, and the effects of the present invention are sufficiently exhibited. May not be possible. More preferably 2500 or more,
Moreover, it is 25,000 or less. More preferably, 300
It is 0 or more and 15000 or less. In addition, in this specification, a weight average molecular weight means the weight average molecular weight in terms of polystyrene by gel permeation chromatography.

The method of producing the copolymer having a leaving group by a proton of the present invention includes, for example, repeating unit (A), repeating unit (B), repeating unit (C) and repeating unit (D). In the case of producing a copolymer having an essential proton-eliminating group, a step of producing a copolymer containing the repeating unit (B), the repeating unit (C) and the repeating unit (D) was performed. After that, a part of the group represented by R ⁵ in the repeating unit (C) is eliminated and replaced with a hydrogen atom to form the repeating unit (A).
A method of carrying out the step of forming is preferable.

By the above-mentioned production method, among the above-mentioned copolymers having a leaving group by a proton of the present invention,
A copolymer having the repeating unit (A) and the repeating unit (C) can be efficiently produced. Further, a monomer forming the repeating unit (A), a monomer forming the repeating unit (B), a monomer forming the repeating unit (C) and a monomer forming the repeating unit (D) are The copolymer of the present invention can also be obtained by polymerizing using a monomer component contained in a predetermined amount.

The monomer forming the repeating unit (B1) is represented by the following general formula (7);

[0036]

[Chemical 8]

A compound represented by the formula (wherein R ² and R ³ are the same as above) is preferable. Of these, methyl α- (1-hydroxybenzyl) acrylate in which R ² is a phenyl group and R ³ is a methyl group, and α- (1 in which R ³ is an ethyl group.
-Hydroxybenzyl) ethyl acrylate, R ³ is n-
Is butyl alpha-(1-hydroxybenzyl) acrylate n- butyl, R ³ is isopropyl group alpha-(1
-Hydroxybenzyl) isopropyl acrylate, R ³
Is a t-butyl group α- (1-hydroxybenzyl)
T-Butyl acrylate is preferred. These α- (1-
Hydroxybenzyl) acrylic acid alkyl ester is
It is preferably synthesized from the corresponding alkyl acrylate and benzaldehyde.

The monomer forming the repeating unit (B2) is represented by the following general formula (8);

[0039]

[Chemical 9]

A compound represented by the formula (in the formula, R ⁸ is the same as above) is preferable. Of these, benzyl α- (hydroxymethyl) acrylate in which R ⁸ is a benzyl group is preferable. The α- (hydroxymethyl) benzyl acrylate is preferably synthesized from benzyl acrylate and paraformaldehyde.

As the monomer forming the repeating unit (B3), the following general formula (9);

[0042]

[Chemical 10]

(In the formula, R ⁹ and R ¹⁰ are the same as above.)
Compounds represented by are preferred. Among them, 3-phenyl-2-propen-1-ol (cinnamic alcohol) in which R ⁹ is a hydrogen atom and R ¹⁰ is a phenyl group is preferable.

The monomer forming the repeating unit (C) is represented by the following general formula (10);

[0045]

[Chemical 11]

A compound represented by the formula (wherein R ⁴ and R ⁵ are the same as above) is preferable. As such a compound, a compound having a structure in which olefins are added to hydroxystyrenes is preferably used.

The above hydroxystyrenes include 2-
Hydroxystyrene, 3-hydroxystyrene, 4-hydroxystyrene and the like are preferable, and one kind or two or more kinds can be used. Further, these may be substituted with an alkyl group, a hydroxyl group, a carboxyl group, a halogen atom or the like. Among these, it is preferable to use 4-hydroxystyrene.

Examples of the above-mentioned olefins include chain olefins having 4 to 20 carbon atoms such as ethylene, propylene, 1-butene, isobutylene and butadiene; cyclopentene,
Cycloolefins such as cyclohexene and cyclopentadiene; norbornylene, bicyclo [2.2.1] hept-2-ene, bicyclo [2.2.1] hepta-2,5
-Diene, 5-norbornene-2-methanol, bicyclo [2.2.2] oct-2-ene, bicyclo [2.
2.2] Octo-2,5-diene, bicyclononadiene, dicyclopentadiene, methylcyclopentadiene dimer, bicyclopentadiene acetate, adamantane, 2-methyleneadamantane and other polycyclic cycloolefins; camphene, terpineol, terpinene-
Olefin terpenes such as 4-ol, α-terpinene, γ-terpinene; olefin alcohols such as allyl alcohol, crotyl alcohol, allyl carbinol; olefin aldehydes such as acrolein, methacrolein, crotonaldehyde; acrylic acid, methacryl Olefin carboxylic acids such as acids, maleic acid and succinic acid; Olefin carboxylic acid esters such as acrylic acid ester, methacrylic acid ester, crotonic acid ester, α-hydroxymethyl acrylic acid ester; methyl vinyl ketone, ethylidene acetone, mesityl oxide Olefin ketones such as; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether; styrene, α-methyl styrene, acrylonitrile, methacrylonitrile It is preferred. These may be used alone or in combination of two or more. Further, these may be substituted with an alkyl group, a hydroxyl group, a carboxyl group, a halogen atom or the like. A preferred form of such olefins is to include isobutylene. In this case, it is preferable to include it as the main component. Especially repeating unit (C)
4-t-butoxystyrene, 3-t-butoxystyrene, 1-t-butoxystyrene, which are easily eliminated and converted to the repeating unit (A), are examples of the monomer forming 4-t-butoxystyrene is more preferable.

Examples of the monomer forming the repeating unit (D) include the following general formula (11);

[0050]

[Chemical 12]

A compound represented by the formula (wherein R ⁶ and R ⁷ are the same as above) is suitable. Examples of such compounds include methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, t-butyl acrylate, isobornyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, t-butyl methacrylate, isobornyl methacrylate. , 1-methylcyclohexyl acrylate, 1-ethylcyclohexyl acrylate, 1-methylcyclopentyl acrylate, 1-ethylcyclopentyl acrylate, 1-methyladamantyl acrylate, 1-ethyladamantyl acrylate, 1-methylcyclohexyl methacrylate, 1-ethylcyclohexyl methacrylate, 1 -Methylcyclopentyl methacrylate, 1-ethyloxy B pentyl methacrylate, 1-methyl adamantyl methacrylate, although it is preferred that 1-ethyl adamantyl methacrylate, especially carbon atoms which preferably has R ⁷ is a leaving group by proton, further R ⁷ is bonded to an oxygen molecule A group having a tertiary carbon atom is preferable, and t-butyl acrylate and t-butyl methacrylate are particularly preferable.

In the above-mentioned method for producing the copolymer, the copolymer containing a repeating unit (A), a repeating unit (B), a repeating unit (C) and a repeating unit (D) having a leaving group capable of leaving a proton. In the case of producing a combined product, a monomer that essentially contains a monomer that forms the repeating unit (B), a monomer that forms the repeating unit (C), and a monomer that forms the repeating unit (D). The amounts of these essential monomers used in the components are such that a is 45 to 90 mol% and b is
Is preferably 5 to 50 mol%, d is 0 to 30 mol%, and a and c are preferably set to satisfy 0.2 ≦ a / (a + c) ≦ 0.95.

In the copolymer having a leaving group by proton of the present invention, one kind of monomer other than the monomer forming the essential repeating unit is used as long as the effects of the present invention can be obtained. Alternatively, two or more kinds may be used. Examples of such a monomer include acrylic acid such as acrylic acid, methyl acrylate, ethyl acrylate, and t-butyl acrylate, and their esters; methacrylic acid such as methacrylic acid, methyl methacrylate, ethyl methacrylate, and t-butyl methacrylate, and their methacrylic acid. Esters; Nitrile group-containing monomers such as acrylonitrile and methacrylonitrile;
Amide group-containing monomers such as acrylamide and methacrylamide; olefins such as ethylene and propylene; aromatic vinyl monomers such as styrene and α-methylstyrene;
Fumaric acid; fumaric acid esters; maleic anhydride; maleic anhydride and the like are preferable.

Examples of the copolymerization method in the step of producing the copolymer of the present invention include a polymerization method using a polymerization initiator; a polymerization method of irradiating ionizing radiation, electron beam or other radiation or ultraviolet rays; and a heating polymerization method. Various conventionally known methods can be used. Further, any polymerization method such as bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization may be used, but solution polymerization using a polymerization initiator is particularly preferable.

In the above copolymerization method, the polymerization initiator may be a peroxide such as benzoyl peroxide or di-t-butyl peroxide; 2,2'-azobisisobutyronitrile, dimethyl 2,2'-. Azo compounds such as azobis (2-methylpropionate) and 2,2'-azobis (2,4-dimethylvaleronitrile) are preferable,
One kind or two or more kinds can be used. Above all, it is preferable to use dimethyl 2,2′-azobis (2-methylpropionate), which is a polymerization initiator having no cyano group. The copolymerization conditions are preferably performed under an atmosphere of an inert gas such as nitrogen gas.

In the above production method, a step of forming a repeating unit (A) by removing a part of the group represented by R ⁵ in the repeating unit (C) and exchanging it with a hydrogen atom is carried out. However, in such a step, for example, a copolymer having the repeating unit (B), the repeating unit (C) and the repeating unit (D) as an essential component is dissolved in a solvent and the repeating unit ( The method of partially removing the group represented by R ⁵ which C) has is suitably applied. At this time, it is preferable to appropriately set the reaction conditions and the like so that the existing amount of the repeating unit (A) in the produced copolymer is within the above range. As the acid catalyst used in this case, the same ones as described above are suitable. Moreover, in order to make the reaction rate easy to suppress, the temperature is preferably 30 to 70 ° C. More preferably, it is performed at 40 to 60 ° C. More preferably,
Trifluoromethanesulfonic acid is used as the acid catalyst.

As means for confirming that the above-mentioned essential structure is present in the copolymer of the present invention or the copolymer produced by the production method of the present invention, for example, ¹ H-NMR, ¹³ C-NMR or the like is preferably applied.

The copolymer having a proton-eliminating group of the present invention has the property that when a free proton coexists, it is affected by the free proton, and its solubility in an alkaline aqueous solution or the like is remarkably increased as compared with that before the action. In addition, since it has good adhesion to the substrate and excellent developability, chemical resistance, and etching resistance, it is a material for photolithography and a low shrinkage material that utilizes the volume expansion of olefins generated by the action of an acid catalyst. It is useful as a copolymer that can be suitably applied to various uses in the chemical industry such as.

[0059]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Unless otherwise specified, "part" is
It means "parts by weight".

Synthesis Example 1 Synthesis of Monomer A (α- (1-hydroxybenzyl) methyl acrylate) 100 equipped with a stirrer, nitrogen inlet tube, thermometer, cooling tube
In a 0 ml flask, methyl acrylate (M = 86) 3
44 g, benzaldehyde (M = 106) 106 g,
1,4-diazabicyclo [2.2.2] octane (M =
112) 56 g and water 36 g were charged, and the mixture was stirred at room temperature for one week. It was washed with 200 g of water three times using a separating funnel, and methyl acrylate was distilled off from the oil layer by vacuum distillation to obtain 180 g of the target product, α- (1-hydroxybenzyl) methyl acrylate.

Synthesis Example 2 Synthesis of Monomer B (α- (hydroxymethyl) benzyl acrylate) 100 equipped with a stirrer, nitrogen inlet tube, thermometer, cooling tube
In a 0 ml flask, 450 g of benzyl acrylate, 83 g of paraformaldehyde, 156 g of 1,4-diazabicyclo [2.2.2] octane, 139 g of water and p-
Charge 1.4 g of methoxyphenol, 100 at 45 ℃
Let react for minutes. After 100 minutes, 600 g of a 20 mass% phosphoric acid aqueous solution was added to stop the reaction. The oil layer was taken out using a separating funnel and washed with water three times using 200 g of water each. To 1 part by weight of the obtained oil layer, 1 part by weight of methanol, 0.4 parts by weight of water, and 10 parts by weight of n-hexane were added to extract the intended product on the side of the aqueous layer. The above-mentioned extraction operation was repeated 3 times, and methanol and water were removed from the obtained aqueous layer by vacuum distillation to obtain 190 g of the desired product, benzyl α- (hydroxymethyl) acrylate.

Example 1Polymerization reaction 100 equipped with stirrer, nitrogen introduction tube, thermometer, cooling tube
Charge a 0 ml flask with 205 g of ethyl acetate and add nitrogen.
While substituting, the temperature was raised to 80 ° C. Prepare in advance here
Saved pt-butoxystyrene (PBS) 200
g, α- (1-hydroxybenzyl) methyl acrylate
(Α-HBAM) 67 g, t-butyl acrylate 3
The flask was charged with 15% by mass of the monomer mixture consisting of 3.5 g.
I put it in. Then, dimethyl 2,2'-azobis (2
-Methyl propionate) (Wako Pure Chemical Industries, Ltd., trade name
"V-601") 21.4 g, ethyl acetate 71.69 g
15% by mass of the initiator solution consisting of
Polymerization started. 10 minutes after the start of the polymerization, the monomer mixture and
The dropping of the initiator solution was started and the monomer mixture was added for 5 hours 50
Initiator solution over 6 hours and 20 minutes each
The dropping was completed. After that, aging was performed for 90 minutes. During polymerization
Kept the internal temperature at 80 ± 1 ° C.

[0063]Selective deprotection reaction The copolymer obtained by the polymerization reaction was precipitated and purified with methanol.
After that, 100 parts of this copolymer was mixed with 200 parts of dioxane and
Dissolved in a mixed solvent of 150 parts of cetone, similar to the polymerization reaction
It heated up to 45 degreeC using the reactor. With an acid catalyst there
Then add 0.04 parts of trifluoromethanesulfonic acid
The selective deprotection reaction was started. 10 minutes after addition of acid catalyst, cool
It was confirmed that isobutene passed through the tube. During reaction, reaction
Sample the solution and throw it in 30 times more ion-exchanged water.
It is then allowed to settle, the polymer is filtered off with a Buchner funnel, and
Rinse well with on-exchange water. Vacuum the polymer taken out
After drying in a dryer,
Dissolve in a 1: 1 mixture of chloroform and measure NMR,
From the ratio of the aromatic proton and the proton of the t-butyl group,
The progress of the protection reaction was monitored. PBS unit 24 mol
%, P-hydroxystyrene (PHS) unit 41 mol
%, Α-HBAM unit 20 mol%, t-butyl acryl
When desorption progresses to a structure consisting of 15 mol% of unit
Then, quench the reaction with ice water to stop the reaction, and then add the reaction solution to 4
Pour into 500 parts of deionized water to purify the precipitate
It was The precipitate is filtered and dried to give a powdery copolymer (A).
Got The copolymer thus obtained was used as Tosoh Corporation.
Manufactured by HLC-8120GPC to measure the molecular weight.
As a result, the weight average molecular weight was 3200, and the molecular weight distribution (Mw
/ Mn) was 1.78. Also, acid value measurement and NM
From the R chart, under this reaction condition, t-butyl acryl
The t-butyl group in the rate unit was not eliminated.

[0064]Physical property confirmation The photolithographic properties of the obtained copolymer (A)
To confirm, the copolymer (A) 20 was added to 50 g of dioxane.
g was dissolved, and 0.2 parts of trifluoromethanesulfonic acid was added.
It was added and reacted at 100 ° C. for 1 hour. Before and after reaction
Polymer (A) is spin coated to give a dry film thickness of 1 μm
Hydrophobic treatment with tetramethyldisilazane
Coated silicon substrate at 23 ℃.
Immersed in a 4.5% aqueous solution of ammonium hydroxide
The thickness of the melted film is DEKTAK II manufactured by Nippon Vacuum Technology Co., Ltd.
  A By measuring with the surface roughness measurement system
The alkaline water dissolution rate (m / sec) was measured. Of film thickness
For the measurement, scrape a part of the film until it reaches the silicon substrate,
Was measured. Dissolution rate depends on the film thickness before immersion
Calculated by subtracting the film thickness after and dividing by the immersion time
It was If the film is completely dissolved within 120 seconds, before immersion
The film thickness was calculated by dividing by the time required for dissolution. alkali
As a solution, 4.5 mass% tetramethylammonium
An aqueous solution of hydroxide was used.

The copolymer (A) has a dissolution rate of 2 before the reaction.
It is as small as 50 × 10 ^-10 m / sec, and the dissolution rate after the reaction is as large as 3000 × 10 ^-10 m / sec or more, which greatly changes the alkaline water dissolution rate before and after the acid-catalyzed reaction, and the silicon substrate. It has been found that the adhesiveness with respect to is also good and is preferable as a polymer for photolithography. The results are shown in Table 1.

Example 2Polymerization reaction 500 equipped with stirrer, nitrogen introduction tube, thermometer, cooling tube
Add 133 g of ethyl acetate to a ml flask and place in nitrogen.
While changing the temperature, the temperature was raised to 80 ° C. Prepare here in advance
155g PBS with α- (hydroxymethyl) ac
Benzyl phosphonate (α-HMAB) 22.5 g, t-butyl
15 of a monomer mixture consisting of 22.5 g of acrylate
Mass% was charged to the flask. Then, dimethyl 2,
2'-azobis (2-methylpropionate) (Jun Wako
Yaku Kogyo KK, trade name "V-601") 28.9 g, acetic acid
15% by weight of the initiator solution consisting of 51.6 g of ethyl acetate
Polymerization was started by throwing it into a Rasco. 10 minutes after the start of polymerization,
Start the dropping of the monomer mixture and the initiator solution, and
5 hours and 50 minutes for compound, 6 hours and 20 minutes for initiator solution
Then, the dropping was completed. 90 minutes aging
I went. The internal temperature was maintained at 80 ± 1 ° C during the polymerization.

[0067]Selective deprotection reaction The copolymer obtained by the polymerization reaction was precipitated and purified with methanol.
After that, 100 parts of this copolymer was mixed with 200 parts of dioxane and
Dissolved in a mixed solvent of 150 parts of cetone, similar to the polymerization reaction
It heated up to 45 degreeC using the reactor. With an acid catalyst there
Then add 0.04 parts of trifluoromethanesulfonic acid
The selective deprotection reaction was started. 10 minutes after addition of acid catalyst, cool
It was confirmed that isobutene passed through the tube. During reaction, reaction
Sample the solution and throw it in 30 times more ion-exchanged water.
It is then allowed to settle, the polymer is filtered off with a Buchner funnel, and
Rinse well with on-exchange water. Vacuum the polymer taken out
After drying in a dryer,
Dissolve in a 1: 1 mixture of chloroform and measure NMR,
From the ratio of the aromatic proton and the proton of the t-butyl group,
The progress of the protection reaction was monitored. PBS unit 21 mol
%, PHS unit 54 mol%, α-HMAB unit 10 mol
%, T-butyl acrylate unit 15 mol%
When desorption progresses to manufacturing, quench the reaction with ice water to stop the reaction
And then add the reaction solution to 4500 parts of deionized water.
Then, precipitation purification was performed. The precipitate is filtered, dried and powdered.
A powdery copolymer (B) was obtained. Thus obtained
The copolymer was manufactured by Tosoh Corporation using HLC-8120GPC.
The weight average molecular weight was 550
0 and molecular weight distribution (Mw / Mn) were 1.61. Well
Also, from the measurement of the acid value and the NMR chart, the reaction conditions
Then, the t-butyl group of the t-butyl acrylate unit is removed.
It wasn't separated.

[0068]Physical property confirmation The photolithographic properties of the obtained copolymer (B)
For confirmation, physical properties were confirmed in the same manner as in Example 1.
It was The copolymer (B) has a dissolution rate of 260 × 1 before the reaction.
0^-Tenm / s is small and the dissolution rate after reaction is 300
0x10^-TenLarge value of m / sec or more, acid-catalyzed reaction
The dissolution rate of alkaline water before and after the
Adhesion to the recon substrate is also good, and photolithography
It has been found that it is preferable as a polymer for ruffy. Conclusion
The results are shown in Table 1.

Example 3Polymerization reaction 200 equipped with stirrer, nitrogen introduction tube, thermometer, cooling tube
In a 0 ml flask, 121 g PBS, cinnamon alcohol
Charge 504g and t-butyl acrylate 12g,
The temperature was raised up to 80 ° C. while substituting. Prepared here in advance
Dimethyl 2,2'-azobis (2-methylpropyl)
Ropionate) (Wako Pure Chemical Industries, Ltd., trade name “V-60
1 ") Initiator dissolution consisting of 115 g and 193 g of ethyl acetate
15% by mass of the liquid was added to the flask to start the polymerization.
10 minutes after the start of polymerization, PBS688 prepared in advance
g, cinnamon alcohol 101 g, t-butyl acrylic resin
Of 67 g of monomer mixture and initiator solution
And the monomer mixture was added to the initiator over 5 hours and 50 minutes.
The solution was added dropwise for 6 hours and 20 minutes.
After that, aging was performed for 90 minutes. Only cinnamon alcohol
Gas chromatography due to its large and low polymerizability
Therefore, the amount of consumed monomer was measured and the amount of
When calculating the polymerization ratio, PBS 65 mol%, cinnamon alco
16 mol% and 19 mol% t-butyl acrylate
there were.

[0070]Selective deprotection reaction The copolymer obtained by the polymerization reaction was precipitated and purified with methanol.
After that, 100 parts of this copolymer was mixed with 200 parts of dioxane and
Dissolved in a mixed solvent of 150 parts of cetone, similar to the polymerization reaction
It heated up to 45 degreeC using the reactor. With an acid catalyst there
Then add 0.04 parts of trifluoromethanesulfonic acid
The selective deprotection reaction was started. 10 minutes after addition of acid catalyst, cool
It was confirmed that isobutene passed through the tube. During reaction, reaction
Sample the solution and throw it in 30 times more ion-exchanged water.
It is then allowed to settle, the polymer is filtered off with a Buchner funnel, and
Rinse well with on-exchange water. Vacuum the polymer taken out
After drying in a dryer,
Dissolve in a 1: 1 mixture of chloroform and measure NMR,
From the ratio of the aromatic proton and the proton of the t-butyl group,
The progress of the protection reaction was monitored. PBS unit 20 mol
%, PHS unit 45 mol%, cinnamon alcohol 16 mol
%, 19 mol% t-butyl acrylate unit
When desorption progresses to manufacturing, quench the reaction with ice water to stop the reaction
And then add the reaction solution to 4500 parts of deionized water.
Then, precipitation purification was performed. The precipitate is filtered, dried and powdered.
A powdery copolymer (C) was obtained. Thus obtained
The copolymer was manufactured by Tosoh Corporation using HLC-8120GPC.
As a result of measuring the molecular weight with a weight average molecular weight of 560
It was 0 and the molecular weight distribution (Mw / Mn) was 1.67. Well
Also, from the measurement of the acid value and the NMR chart, the reaction conditions
Then, the t-butyl group of the t-butyl acrylate unit is removed.
It wasn't separated.

[0071]Physical property confirmation The photolithographic properties of the obtained copolymer (C)
For confirmation, physical properties were confirmed in the same manner as in Example 1.
It was The copolymer (C) has a dissolution rate of 54 × 10 5 before the reaction.
^-TenSmall as m / sec, and dissolution rate after reaction is 3000
× 10^-TenIt becomes a large value of m / sec or more and before the acid catalyst reaction.
The dissolution rate of alkaline water afterwards will change significantly and
Adhesion to the control board is also good, and photolithography
It has been found to be preferable as a polymer for fees. result
Is shown in Table 1.

[0072]

[Table 1]

Table 1 will be described below. In the polymerization monomer composition, PBS is pt-butoxystyrene, α-HBAM is methyl α- (1-hydroxybenzyl) acrylate, and α-HMAB is α- (hydroxymethyl). Benzyl acrylate. In the polymer structural unit, (A) is a structural unit formed by a selective deprotection reaction in PBS, and (B) is formed by any one of α-HBAM, α-HMAB and cinnamic alcohol. (C) is a structural unit formed of PBS, and (D) is a structural unit formed of t-butyl acrylate.

[0074]

EFFECT OF THE INVENTION Since the copolymer having a leaving group by a proton of the present invention has the above-mentioned constitution, the characteristics such as the change in solubility in an alkaline aqueous solution before and after the treatment by a free proton, the adhesion to the substrate. The property, the developability, the chemical resistance and the etching resistance are exhibited at a high level, and it can be suitably applied to various uses.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinichi Goto             5-8 Nishiomitabicho Suita City, Osaka Prefecture             Within Nippon Shokubai (72) Inventor Motohiro Arakawa             5-8 Nishiomitabicho Suita City, Osaka Prefecture             Within Nippon Shokubai (72) Inventor Tadayoshi Ugamura             5-8 Nishiomitabicho Suita City, Osaka Prefecture             Within Nippon Shokubai (72) Inventor Masatoshi Yoshida             5-8 Nishiomitabicho Suita City, Osaka Prefecture             Within Nippon Shokubai F-term (reference) 2H025 AA02 AA04 AA09 AA14 AB16                       AB17 AC01 AD03 BE00 BE10                       BG00 CB14 CB17 CB41 CB45                 4J100 AB07P AB07Q AL03S AL08S                       AL29R BA03P BA03Q BA04Q                       BA10Q BA13Q BA16Q BA20Q                       BA40Q BC02Q BC03Q BC03S                       BC04Q BC04S BC07Q BC08S                       BC09S BC43Q CA06 CA31                       HA08 JA38

Claims (5)

[Claims] 1. A copolymer having an alcoholic hydroxyl group and an aromatic ring and having a leaving group by a proton, the copolymer having a leaving group by a proton,
A copolymer having a leaving group by a proton, which essentially comprises a repeating unit having both an alcoholic hydroxyl group and an aromatic ring. 2. The copolymer having a leaving group by a proton is represented by the following general formula (1); [In the formula, R ¹ , R ⁴ and R ⁶ are the same or different and each represents a hydrogen atom or a methyl group. R ² represents a group having an aromatic ring. R ³ and R ⁷ are the same or different and each represents a substituted or unsubstituted alkyl group. R ⁵ represents a leaving group by a proton. a, b1, c and d represent the mole fractions of the repeating units (A), (B1), (C) and (D) in the copolymer, respectively. ] The repeating unit (A) and repeating unit (B1) represented by these are essential, or repeating unit (A) and repeating unit (B1) and repeating unit (C) and / or repeating unit (D) The copolymer having a leaving group by a proton according to claim 1, which is essential. 3. The copolymer having a leaving group by proton is represented by the following general formula (2): [In the formula, R ¹ , R ⁴ and R ⁶ are the same or different and each represents a hydrogen atom or a methyl group. R ⁵ represents a leaving group by a proton. R ⁷ represents a substituted or unsubstituted alkyl group. R ⁸ represents a group having an aromatic ring. a, b2, c
And d are repeating units (A) in the copolymer,
It represents the mole fractions of (B2), (C) and (D). ] The repeating unit (A) and repeating unit (B2) represented by are essential, or repeating unit (A) and repeating unit (B2) and repeating unit (C) and / or repeating unit (D) The copolymer having a leaving group by a proton according to claim 1 or 2, which is essential. 4. The copolymer having a proton leaving group is represented by the following general formula (3): [In the formula, R ¹ , R ⁴ , R ⁶ and R ⁹ represent a hydrogen atom or a methyl group. R ⁵ represents a leaving group by a proton. R ⁷
Represents a substituted or unsubstituted alkyl group. R ¹⁰ represents a group having an aromatic ring. a, b3, c and d represent the mole fractions of the repeating units (A), (B3), (C) and (D) in the copolymer, respectively. ] The repeating unit (A) and repeating unit (B3) represented by are essential, or repeating unit (A) and repeating unit (B3) and repeating unit (C) and / or repeating unit (D) The copolymer having a leaving group by a proton according to claim 1, which is essential. 5. A in the mole fraction of the repeating unit
Is 45 to 90 mol%, the total of b1, b2 and b3 is 5 to 50 mol%, d is 0 to 30 mol%, and a and c are 0.2 ≦ a /. (A + c) ≦ 0.95
The copolymer having a proton-eliminating group according to claim 2, 3 or 4, wherein