JP2003105032A - Copolymer bearing group removable by proton - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copolymer bearing a group removable by a proton which fulfils at a high level both characteristics such as changes in solubility in an aqueous alkali solution by treatment with a free proton, and the like and adhesion to a substrate, and is suitably applied to various uses. SOLUTION: The copolymer bearing a group removable by a proton is represented by general formula (1) [wherein R<1> , R<3> , R<4> and R<6> are the same or different and are each a hydrogen atom or a methyl group; R<2> is a 6-30C substituted or unsubstituted alicyclic group; R<5> is a group removable by a proton; and a, b, c and d are the existing amount (mole%) of the recurring units (A), (B), (C) and (D), respectively, in the copolymer] and comprises as essential ingredients the recurring unit (A), the recurring unit (D), and the recurring unit (B) and/or the recurring unit (C).

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., an alkaline aqueous solution is produced before and after irradiation. The characteristics such as solubility in water greatly change. 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 Japanese Patent Laid-Open No. 11-171932, p.
A radiation-sensitive resin composition containing a copolymer having three repeating units of a hydroxystyrene / styrene / isobornyl acrylate structure is disclosed. This copolymer can be used as a photolithography material or the like because the isobornyl group is eliminated by a free proton and converted into a carboxyl group. However,
Since the isobornyl ester is a secondary ester, desorption is relatively unlikely to occur, and there is a problem that it is difficult to increase the ratio of the dissolution rate in the alkaline aqueous solution after the treatment with the free protons and before the treatment. In the present specification, the treatment with free protons means that hydrogen ions act on the copolymer.

In Japanese Patent Laid-Open No. 4-212158, p-
A radiation-sensitive resin composition containing a copolymer having three repeating units of a hydroxystyrene / p-butoxystyrene / t-butylmethacrylate structure is disclosed. This copolymer can be used as a photolithography material or the like because the t-butyl group is eliminated by the treatment with free protons and converted into a carboxyl group. Since the t-butyl ester is a tertiary ester, desorption is relatively easy to occur, and the ratio of the dissolution rate in the alkaline aqueous solution after the treatment with the free protons and before the treatment can be easily increased.

However, since this copolymer does not have a strong hydrophobic group, it is necessary to increase the p-butoxystyrene unit ratio in order to reduce the dissolution rate in an alkaline aqueous solution before the treatment with free protons. A copolymer containing a large amount of p-butoxystyrene units is necessarily p-.
There is a drawback that the hydroxystyrene unit is reduced and the adhesion to the substrate is poor. In this copolymer, it is not easy to increase the ratio of the dissolution rate in the alkaline aqueous solution after the treatment with free protons and before the treatment while maintaining the adhesion to various substrates. In the present specification, good adhesion to various substrates means that when various substrates coated with a copolymer are immersed in an alkaline aqueous solution or the like, a coating film is peeled from the substrate or cracks occur. I mean not.

In JP-A-11-72920, hydroxy (α-methyl) styrenes / t-butyl (meth) are disclosed.
A radiation-sensitive composition containing a copolymer having a repeating unit derived from acrylate / t-butoxy (α-methyl) styrene is disclosed, and JP-A-4-355761 discloses a carboxylic acid in the molecule. A positive type photosensitive resin composition containing a compound having an isobornyl ester structure is disclosed, and JP-A-2-62544 discloses hydroxy (α-alkyl) styrenes / alkoxy (α).
Disclosed is a photoresist composition comprising a polymer having a repeating unit having a structure derived from -alkyl) styrenes. Moreover, in Japanese Patent No. 2839159,
As a method for producing a polymer derivative for use in a positive resist composition, use of a polymer having an acid labile pendant group is disclosed. However, even in these techniques, by increasing the ratio of the dissolution rate in the alkaline aqueous solution after the treatment with free protons and before the treatment while maintaining the adhesion with various substrates, that is, the adhesion with various substrates, the free protons Dissolution inhibition before treatment,
Further, by making all the properties such as the solubility in the alkaline aqueous solution after the treatment excellent, there is room to devise a material that can sufficiently increase the contrast when used as a material for photolithography, for example. It was

[0007]

In view of the above, the present invention has a high level of compatibility between the characteristics such as a change in solubility in an alkaline aqueous solution before and after treatment with free protons and substrate adhesion, and is suitable for various applications. It is an object of the present invention to provide a copolymer having a leaving group by a proton that can be applied to

[0008]

The present invention provides the following general formula (1);

[0009]

[Chemical 2]

[Wherein R¹, R^Three, R^FourAnd R⁶Is the same
One or differently represents a hydrogen atom or a methyl group. R
^TwoRepresents a substituted or unsubstituted alicyclic group having 6 to 30 carbon atoms.
You R ⁵Represents a leaving group by a proton. a, b,
c and d are repeating units in the copolymer
Abundance (mol%) of (A), (B), (C) and (D)
Represents ], And the repeating unit (A)
Unit (D) and repeating unit (B) and / or repeating
It has a leaving group by a proton that requires the unit (C)
Is a copolymer.

The present inventors have investigated various copolymers having a leaving group by a proton, and found that the structure of the copolymer has 6 to 30 carbon atoms, preferably 6 to 20 carbon atoms.
More preferably, a specific repeating unit having a substituted or unsubstituted alicyclic group having 6 to 12 carbon atoms, a specific repeating unit having a group capable of easily leaving to improve the hydrophilicity of the copolymer, and a copolymer By first focusing on the fact that a repeating unit having a specific structure that imparts hydrophilicity to a polymer and / or a repeating unit having a specific structure that essentially has one leaving group by a proton may be used, ,
Promptly dissolves the copolymer in alkaline aqueous solution by treatment with free protons without impairing the adhesion to the substrate.
At the same time, they have found that they can be made larger, and have come up with the idea that they can solve the above problems perfectly. Further, in such a copolymer, the proportion of the essential repeating unit is specified, and the substituted or unsubstituted alicyclic group having 6 to 30 carbon atoms and the leaving group by proton are specified in the repeating unit. It has been found that the effects as described above can be more sufficiently exhibited by using the above as the base, and the present invention has been achieved.

In the copolymer of the present invention, the adhesion to various substrates is mainly expressed by the repeating unit (B). Further, the dissolution inhibitory property before treatment with free protons is expressed by the repeating unit (A), the repeating unit (C) and the repeating unit (D), and this property is mainly shown in the repeating unit (A). Is considered to have a large contribution. Further, the solubility in the alkaline aqueous solution after the treatment is expressed by the repeating unit (A), the repeating unit (B), the repeating unit (C) and the repeating unit (D). ) And the repeating unit (D) are compared, it is considered that the contribution of the repeating unit (D) is 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), the repeating unit (D), Only by making the repeating unit (B) and / or the repeating unit (C) indispensable, characteristics such as change in solubility in alkaline aqueous solution before and after treatment with free protons and substrate adhesion can be achieved at a high level, and various It can be suitably applied to various uses. The present invention is described in detail below.

The proton-releasable group-containing copolymer of the present invention is represented by the above general formula (1) and has repeating unit (A), repeating unit (D) and repeating unit (B).
And / or the repeating unit (C) is essential. In such a copolymer, the repeating unit (A), the repeating unit (D), and the repeating unit (B) are indispensable forms, the repeating unit (A), the repeating unit (D), and the repeating unit (C). ), And a form in which four kinds of the repeating unit (A), the repeating unit (D), the repeating unit (B) and the repeating unit (C) are essential. These repeating units may be the same or different. More specifically, among the above-mentioned forms, a form in which three kinds of repeating units (A), repeating units (B) and repeating units (D) are essential, and repeating units (A) and repeating units The form in which four kinds of (B), repeating unit (C) and repeating unit (D) are essential has a large change in solubility in an alkaline aqueous solution before and after treatment with free protons, and adheres to various substrates. This is the preferred form because it can further enhance the sex. Also,
The addition form of these repeating units is not particularly limited, and examples thereof include a random form, a block form, and an alternate form.

In the above general formula (1), 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, Examples include sulfuric acid and nitric acid. These may be used alone or in combination of two or more.

Examples of the proton-eliminating group include branched alkyl groups such as t-butyl group and isopropyl group; and alicyclic skeletons such as cyclobutyl group, cyclopentyl group, cyclohexyl group and cycloheptyl group. Formula C _n
A cycloalkyl group represented by H _2n (n is an integer of 3 or more); a hydrogen atom of a cycloalkyl group such as 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 1-methylcyclopentyl group, 1-ethylcyclopentyl group A group in which one or more of are substituted by a linear or branched alkyl group; formed from a compound having a spiro ring such as spiroheptane or spirooctane in which a bridged hydrocarbon is introduced into a cycloalkyl group A group; a tetrahydropyranyl group, a tetrahydrofuranyl group, a 3-oxocyclohexyl group,
Methoxymethyl group, ethoxymethyl group, 1-methoxyethyl group, 1-ethoxyethyl group, 1-butoxyethyl group, t-butoxycarbonyl group, trimethylsilyl group,
Functional group having a hetero atom such as triethylsilyl group; isobornyl group, adamantyl group, 1-methyladamantyl group, 1-ethyladamantyl group, norbornyl ring,
Bornene ring, Menthyl ring, Menthane ring, Camouflage ring,
A substituent having a terpene ring formed from a compound such as isocamphor ring, sesquiterpene ring, sandton ring, diterpene ring, triterpene ring, tsujang, sabinene, tsujon, karan, curene, pinane, norpinane, bornane, camphene, tricyclene; Examples include cholesteric rings, bile acids, digitoids, steroid skeletons such as steroid saponins, and groups formed from polycyclic compounds. These are a hydroxyl group, a carboxyl group, and 1 to 1 carbon atoms.
4 may be substituted with an alkyl group, a hydroxyalkyl group, a carboxyalkyl group or the like.

Among the proton-eliminating groups exemplified above, a t-butyl group, a t-butoxycarbonyl group, a tetrahydropyranyl group, or a trimethylsilyl group is preferable. That is, in the general formula (1), R ⁵ is preferably a t-butyl group, a t-butoxycarbonyl group, a tetrahydropyranyl group or a trimethylsilyl group.
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. Specifically, examples of the other substituents include organic groups such as alkyl groups (ethyl group, t-butyl group, etc.); alkoxy groups; carboxyl groups; hydroxyl groups; amino groups; sulfone groups and halogen elements, etc. Is mentioned. Further, the above-mentioned other substituents may have a structure such as a carboxylate, an ammonium salt, a quaternary ammonium salt, or a metal salt.

6 to 30 carbon atoms in the above general formula (1)
The substituted or unsubstituted alicyclic group is, for example, cycloalkyl in which an alicyclic skeleton such as a cyclohexyl group or a cycloheptyl group is represented by the general formula C _n H _{2 n} (n is an integer of 6 or more). Group; one or two or more hydrogen atoms of a cycloalkyl group such as 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 1-methylcyclopentyl group, 1-ethylcyclopentyl group are straight-chain or branched alkyl groups A group formed by a compound having a spiro ring such as spiroheptane in which a bridging hydrocarbon is introduced into a cycloalkyl group, an isobornyl group, an adamantyl group, a 1-methyladamantyl group, 1- Ethyl adamantyl group, norbornyl ring, bornene ring, menthyl ring, menthane ring, camphor ring, isocamphor ring, sesquiterpene ring A substituent having a terpene ring formed from a compound such as a Sandton ring, a diterpene ring, a triterpene ring, tujan, sabinene, tsujon, karan, karen, pinane, norpinane, bornane, camphen, tricyclene; a cholesteric ring, a bile acid, a digitalloid. ,
Examples thereof include steroid skeletons such as steroid saponins and groups formed from polycyclic compounds. 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 alicyclic groups having 6 to 30 carbon atoms exemplified above, a cyclohexyl group, an isobornyl group and an adamantyl group are preferable. That is, in the general formula (1), R ² is preferably a cyclohexyl group, an isobornyl group or an adamantyl group.

The proton-eliminating group-containing copolymer of the present invention preferably has a weight average molecular weight of 2,000 to 30,000. If it is less than 2,000, the heat resistance may be poor, and if it exceeds 30,000, 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, 2500-1
5000, and more preferably 3000 to 9000
Is. In addition, in this specification, a weight average molecular weight means the weight average molecular weight in terms of polystyrene by gel permeation chromatography.

In the copolymer having a leaving group by a proton of the present invention, in the above general formula (1), the above a,
It is preferable that b, c and d satisfy the requirements that a is 5 to 30 mol%, b + c, that is, the sum of b and c is 40 to 94 mol%, and d is 1 to 30 mol%. As a result, the effects of the present invention can be more fully exhibited. More preferably, a is 5 to 30 mol% and b + c is 60.
-90 mol%, d is 1-30 mol%, More preferably, a is 10-25 mol% and b + c is 65-8.
9 mol% and d is 1 to 25 mol%. In the above description, the existing amount of all repeating units constituting the copolymer is 100 mol%.

In the present invention, the above b is 40 to 90 mol%.
Is preferred. If it is less than 40 mol%, the hydrophilicity of the copolymer may be lowered and the adhesion to the substrate may be lowered. If it exceeds 90 mol%, the treatment with free protons, that is, the free protons, may occur. The solubility in an aqueous alkaline solution may be too high even before the treatment with. It is more preferably 40 to 80 mol%, and even more preferably 40 to 70 mol%.

As a method for producing the copolymer having a leaving group by a proton of the present invention, for example, the repeating unit (A), the repeating unit (D) and the repeating unit (C) are prepared. After performing the step of producing an essential copolymer, the above repeating unit is prepared by removing a part or all of the group represented by R ⁵ in the above repeating unit (C) and exchanging it with a hydrogen atom. A method of performing the step of forming (B) is suitable. By such a manufacturing method,
Of the above-mentioned copolymer having a leaving group by a proton of the present invention, the repeating unit (A) and the repeating unit (D)
And a form in which three kinds of repeating units (B) are essential and a form in which four kinds of repeating units (A), repeating units (D), repeating units (B) and repeating units (C) are essential It will be possible to manufacture. Further, a monomer forming the repeating unit (A), a monomer forming the repeating unit (D), a monomer forming the repeating unit (B) and / or a monomer forming the repeating unit (C). It is also possible to obtain the copolymer of the present invention by polymerizing using a monomer component containing the body in a predetermined amount.

In the step of producing a copolymer containing the repeating unit (A), the repeating unit (D) and the repeating unit (C) as an essential component, the monomer forming the repeating unit (A) is used. Preferably, it is carried out by copolymerizing a monomer component which essentially contains the monomer forming the repeating unit (D) and the monomer forming the repeating unit (C).

Examples of the monomer forming the repeating unit (A) include the following general formula (2);

[0025]

[Chemical 3]

(In the formula, R ¹ and R ² are the same as above.), And the like (meth) acrylic acid ester.
As such a monomer, for example, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate and the like are suitable.

The monomer forming the repeating unit (D) is represented by the following general formula (3):

[0028]

[Chemical 4]

(Meth) acrylic acid ester represented by the formula (wherein R ⁶ is the same as above), that is, t-butyl (meth) acrylate is used. Examples of the monomer forming the repeating unit (C) include the following general formula (4);

[0030]

[Chemical 5]

(In the formula, R ⁴ and R ⁵ are the same as above.)
And the like. As such a compound, a compound having a structure in which olefins are added to hydroxystyrenes is preferably used.

Examples of the hydroxystyrenes include 2-hydroxystyrene, 3-hydroxystyrene, 4-hydroxystyrene and the like.
More than one species 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.

The above olefins are not particularly limited and include, for example, chain olefins having 4 to 20 carbon atoms such as ethylene, propylene, 1-butene, isobutylene and butadiene; cycloolefins such as cyclopentene, 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] oct-2,5-
Diene, bicyclononadiene, dicyclopentadiene,
Polycyclic cycloolefins such as methylcyclopentadiene dimer, bicyclopentadiene acetate, adamantane and 2-methyleneadamantane; olefin terpenes such as camphene, terpineol, terpinen-4-ol, α-terpinene and γ-terpinene; allyl alcohol, Olefin alcohols such as crotyl alcohol and allyl carbinol; Olefin aldehydes such as acrolein, methacrolein and crotonaldehyde; Olefin carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and succinic acid; Acrylic acid esters and methacrylic acid esters , Carboxylic acid esters such as crotonic acid ester and α-hydroxymethylacrylic acid ester; methyl vinyl ketone, ethylideneacetone, mesityl oxide, etc. Olefins ketones; methyl vinyl ether, ethyl vinyl ether and butyl vinyl ether; styrene, alpha-methyl styrene, acrylonitrile, methacrylonitrile, and the like. 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.

In the method for producing the copolymer, the monomer forming the repeating unit (A), the monomer forming the repeating unit (D) and the monomer forming the repeating unit (C) are used. The amount of these essential monomers used in the monomer component that is essential is a is 5 to 30 mol%, b +
It is preferable that c is set in the range of 40 to 94 mol% and d is set in the range of 1 to 30 mol%. Further, one or more monomers other than the above-mentioned essential monomers may be used as long as the effects of the present invention are exhibited. Such a monomer is not particularly limited, and examples thereof include styrene compounds such as styrene, α-methylstyrene, and 4-hydroxystyrene; (meth) acrylonitrile; (meth) acrylic acid and its esters, α-hydroxy. Methylacrylic acid and its esters, 5-norbornene-2-carboxylic acid and its esters, anhydrous-5-norbornene-2,3-dicarboxylic acid and its ester, 5
-Norbornene-2-methanol, maleic anhydride and its esters, maleimides and the like.

The copolymerization method in the step of producing the copolymer of the present invention, which essentially includes the repeating unit (A), the repeating unit (D) and the repeating unit (C), includes, for example, polymerization using a polymerization initiator. Method; ionizing radiation,
Various conventionally known methods such as a polymerization method of irradiating radiation such as an electron beam or ultraviolet rays; a polymerization method of heating can be used.

In the above copolymerization method, the polymerization initiator is not particularly limited, and examples thereof include peroxide; 2,2'-azobisisobutyronitrile, dimethyl 2,2'-azobis (2-methylpropio). Azo compound) and the like, and one kind or two or more kinds can be used. Preferably, a polymerization initiator having no cyano group is used. The copolymerization conditions are preferably performed under an atmosphere of an inert gas such as nitrogen gas.

In the above-mentioned production method, a step of forming a repeating unit (B) by eliminating a part or all of the group represented by R ⁵ in the repeating unit (C) and exchanging it with a hydrogen atom. In such a step, for example, a copolymer having the repeating unit (A), the repeating unit (D) and the repeating unit (C) as an essential component is dissolved in a solvent, and repeated using an acid catalyst. A method of selectively removing part or all of the group represented by R ⁵ which the unit (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 (B) in the produced copolymer is within the above range. Examples of the acid catalyst used in this case include the same ones as described above. Preferably, in order to cause the above selective desorption, the temperature is 30 to 70 ° C. More preferably 40
Perform at ~ 60 ° C. More preferably, trifluoromethanesulfonic acid is used as the acid catalyst.

As means for confirming the presence of the above essential structure 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 and the like are preferably applied.

The copolymer having a leaving group by a proton of the present invention has a property that when a free proton coexists, it is affected by the free proton and the solubility in an alkaline aqueous solution or the like is remarkably increased as compared with that before the action. Moreover, since it has good adhesion to the substrate, it is suitably 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. It is useful as a copolymer that can be obtained.

[0040]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "part" means "part by weight".

Example 1Polymerization reaction 200 equipped with stirrer, nitrogen introduction tube, thermometer, cooling tube
A 0 ml flask was charged with 553 parts of ethyl acetate and charged with nitrogen.
While substituting, the temperature was raised to 80 ° C. Prepare in advance here
Preserved pt-butoxystyrene (PBS) 681
Part, isobornyl acrylate (IBA) 113 parts, t
-Contains 14 parts of butyl methacrylate (t-BMA)
15% by weight of the monomer mixture was charged to the flask. Continued
Dimethyl 2,2'-azobis (2-methylpropio
Nate) (Wako Pure Chemical Industries, Ltd., trade name "V-601")
1 part of an initiator solution consisting of 113 parts and 193 parts of ethyl acetate
Polymerization was initiated by charging 5% by weight into the flask. Polymerization
After 10 minutes, start dropping the monomer mixture and the initiator solution.
Then, the monomer mixture takes 5 hours and 50 minutes, and the initiator solution is
The dropping was completed in 6 hours and 20 minutes. afterwards
It was aged for 90 minutes. Internal temperature of 80 ± 1 ℃ during polymerization
Kept at. 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 5700, and the molecular weight distribution (Mw
/ Mn) was 1.60. From the measurement of residual monomer,
The polymerization rate of PBS is 90%, the polymerization rate of IBA is 92%, t
-The polymerization rate of BMA was 99% or more. So got
The structure of the prepared copolymer is 85 mol% of PBS unit, IBA
It was calculated that the position was 13 mol% and the t-BMA unit was 2 mol%.

[0042]Selective elimination 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
Dissolve in a mixed solvent of 150 parts of seton and raise the temperature to 45 ° C.
It was There, trifluoromethanesulfone as an acid catalyst
The selective elimination reaction was started by adding 0.04 part of the acid. Acid touch
10 minutes after adding the medium, isobutene was confirmed to have passed through the cooling tube.
It was Continue the reaction as it is, and 60 minutes after the addition of the acid catalyst
The reaction was stopped by cooling. 4500 parts of reaction solution
It was poured into on-exchanged water to carry out precipitation purification. The precipitate is filtered
After drying, the copolymer (A) in powder form was obtained. NM
Ratio of aromatic proton by t and proton of t-butyl group
From, IBA unit 13 mol%, p-hydroxystyrene
(PHS) unit 51 mol%, PBS unit 34 mol%, t
-Confirmed that the structure consists of 2 mol% of BMA unit.
It was The weight average molecular weight is measured by GPC.
5,000 and molecular weight distribution (Mw / Mn) of 1.51
It was In addition, from the acid value measurement and the NMR chart,
Under the reaction conditions, an isobornyl group of IBA unit, t-BMA
The t-butyl group of the unit was not eliminated.

[0043]Physical property confirmation Confirm the photolithographic properties of the obtained copolymer
Therefore, dissolve 20 g of copolymer (A) in 50 g of dioxane.
Dissolve and add 0.2 parts of trifluoromethanesulfonic acid
And reacted at 100 ° C. for 1 hour. Copolymer before and after reaction
(A) is spin-coated to a dry film thickness of 1 μm
Coating on a silicon substrate as shown in
Immersion in a 4.5% aqueous solution of lumonium hydroxide
The film thickness of the melted film is DEKTAK manufactured by Nippon Vacuum Technology Co., Ltd.
II A For measuring with a surface roughness measuring system
The alkaline water dissolution rate (m / sec) was measured from. result
Is shown in Table 1. The copolymer (A) has a dissolution rate before the reaction
6.5 x 10^-TenVery small at m / sec and after reaction
Dissolution rate is 2.4 × 10^-7m / sec and very large value
The alkaline water dissolution rate before and after the acid-catalyzed reaction varies significantly.
In addition, it has good adhesion to silicon substrates.
Is preferable as a polymer for photolithography.
I understood.

Comparative Example 1 In Example 1, 681 parts of PBS and 9 parts of t-BMA were used.
A comparative copolymer (A ′) was obtained by performing the same operation as in Example 1 except that 2 parts were used and IBA was not used. Further, a physical property confirmation experiment was conducted in the same manner as in Example 1 using the comparative copolymer (A ′), and the results are shown in Table 1. In the physical property confirmation experiment, the comparative copolymer (A ′) had a dissolution rate of 10 ⁻⁷ m / sec or more before and after the reaction, and there was almost no change in the dissolution rate before and after the reaction. As a result, it was not preferable as a polymer for photolithography.

Example 2 In Example 1, 675 parts of PBS, 120 parts of isobornyl methacrylate (IBMA) and 1 part of t-BMA were used.
A copolymer (B) was obtained in the same manner as in Example 1, except that 4 parts were used and the selective elimination reaction was performed for 120 minutes. Further, a physical property confirmation experiment was carried out in the same manner as in Example 1 using the copolymer (B), and the results are shown in Table 1. As a result of measuring the molecular weight of the copolymer after the polymerization reaction by using HLC-8120GPC manufactured by Tosoh Corporation, a weight average molecular weight of 530
It was 0 and the molecular weight distribution (Mw / Mn) was 1.68. From the measurement of residual monomer, the polymerization rate of PBS was 86%, IBM
The polymerization rate of A was 94%, and the polymerization rate of t-BMA was 99% or more. Therefore, the structure of the obtained copolymer was calculated to be 84 mol% for PBS unit, 13 mol% for IBMA unit and 3 mol% for t-BMA unit. The copolymer obtained after the selective deprotection reaction had an IBMA unit of 13 mol% and p-
Hydroxystyrene (PHS) unit 64 mol%, PBS
It was confirmed that the structure consisted of 20 mol% units and 3 mol% t-BMA units. The molecular weight measured by GPC was 4500 for the weight average molecular weight and the molecular weight distribution (Mw / M
n) was 1.49. Further, from the acid value measurement and the NMR chart, under this reaction condition, the isobornyl group of the IBMA unit and the t-butyl group of the t-BMA unit were hardly eliminated. In the physical property confirmation experiment, the copolymer (B) had a very low dissolution rate of 3.8 × 10 ⁻⁹ m / sec before the reaction and a dissolution rate of 1.0 × 10 ⁻⁷ m after the reaction.
It was found to be preferable as a polymer for photolithography since the rate of dissolution in alkaline water before and after the acid-catalyzed reaction greatly changes, and the adhesion to the silicon substrate is also good, which is a very large value such as / sec.

Comparative Example 2 In Example 2, 675 parts of PBS and 9 parts of t-BMA were used.
The same operation as in Example 2 was carried out except that 2 parts were used and IBMA was not used, to obtain a comparative copolymer (B ′). Also, using the comparative copolymer (B '), Example 1 was used.
A physical property confirmation experiment was conducted in the same manner as in, and the results are shown in Table 1. In the physical property confirmation experiment, the comparative copolymer (B ′) had a dissolution rate of 10 ⁻⁷ m / sec or more before and after the reaction, and there was almost no change in the dissolution rate before and after the reaction. as a result,
It was not preferable as a polymer for photolithography.

Example 3 In Example 1, 451 parts of PBS and 230 of IBA were used.
Part, 121 parts of t-BMA were used, and the selective elimination reaction was carried out in 1
Except having carried out for 20 minutes, the same operation as in Example 1 was carried out to obtain a copolymer (C). In addition, a physical property confirmation experiment was conducted in the same manner as in Example 1 using the copolymer (C), and the results are shown in Table 1.
It was shown to. In the physical property confirmation experiment, the copolymer (C) was
The dissolution rate before the reaction was extremely low at 2.8 × 10 ^-9 m / sec, and the dissolution rate after the reaction was very high at 1.0 × 10 ^-7 m / sec or more, which was before and after the acid catalyzed reaction. It was found that the dissolution rate of the alkaline water in Example 1 changed greatly, and the adhesiveness to the silicon substrate was good, which is preferable as a polymer for photolithography.

Example 4 In Example 1, 445 parts of PBS and 24 parts of IBMA were used.
A copolymer (D) was obtained in the same manner as in Example 1, except that 1 part and 122 parts of t-BMA were used and the selective elimination reaction was carried out for 120 minutes. Further, a physical property confirmation experiment was carried out in the same manner as in Example 1 using the copolymer (D), and the results are shown in Table 1. In the physical property confirmation experiment, the copolymer (D) had a very low dissolution rate of 5 × 10 ⁻¹⁰ m / sec before the reaction and a dissolution rate of 1.0 × 10 ⁻⁷ m / sec or more after the reaction. It was found that the value is very large, the dissolution rate of alkaline water before and after the acid-catalyzed reaction changes greatly, and the adhesion to a silicon substrate is good, which is preferable as a polymer for photolithography.

Example 5 In Example 1, 488 parts of PBS and 308 of IBA were used.
Part, t-BMA of 12 parts, and selective elimination reaction of 12 parts
A copolymer (E) was obtained by performing the same operations as in Example 1 except that 0 minutes was carried out. Further, a physical property confirmation experiment was conducted in the same manner as in Example 1 using the copolymer (E), and the results are shown in Table 1.
It was shown to. In the physical property confirmation experiment, the copolymer (E) was
The dissolution rate before the reaction was very low at 5.0 × 10 ^-9 m / sec, and the dissolution rate after the reaction was as high as 9.0 × 10 ^-8 m / sec, which was the alkali before and after the acid-catalyzed reaction. It was found that the water dissolution rate was significantly changed and the adhesion to the silicon substrate was also good, which is preferable as a polymer for photolithography.

Example 6 In Example 1, 477 parts of PBS and 101 of IBA were used.
Part, 230 parts of t-BMA were used, and the selective elimination reaction was performed in 1
Except having carried out for 20 minutes, the same operation as in Example 1 was carried out to obtain a copolymer (F). Further, a physical property confirmation experiment was carried out in the same manner as in Example 1 using the copolymer (F), and the results are shown in Table 1.
It was shown to. In the physical property confirmation experiment, the copolymer (F) was
The dissolution rate before the reaction was a little small, 9.3 × 10 ^-9 m / sec, and the dissolution rate after the reaction was 1.0 × 10 ^-7 m / sec or more, which was a very large value. It was found that the dissolution rate of alkaline water in (1) changes greatly and the adhesiveness to a silicon substrate is good, which is preferable as a polymer for photolithography.

Comparative Example 3 In Example 2, 577 parts of PBS and 231 of IBA were used.
Comparative procedure (C ') was obtained by the same procedure as in Example 2, except that the parts were used and t-BMA was not used. In addition, a comparative copolymer (C ′) was used in Example 1
A physical property confirmation experiment was conducted in the same manner as in, and the results are shown in Table 1. In the physical property confirmation experiment, the comparative copolymer (C ′) had a small dissolution rate of 10 ⁻⁹ m / sec or less before and after the reaction, and there was almost no change in the dissolution rate before and after the reaction. As a result, it was not preferable as a polymer for photolithography.

[0052]

[Table 1]

Table 1 will be described below. In the polymerization monomer composition, IBA is isobornyl acrylate, IBMA is isobornyl methacrylate, PBS is pt-butoxystyrene, and t-BMA is t-butyl methacrylate. Is. In the structural unit of the polymer, (A) is IBA,
Is a structural unit formed by IBMA, (B) is a structural unit formed by p-hydroxystyrene, (C) is a structural unit formed by pt-butoxystyrene, (D) is a structural unit formed of t-butyl methacrylate.

[0054]

EFFECTS OF THE INVENTION The copolymer having a leaving group by a proton of the present invention has the above-mentioned constitution. When a free proton coexists, the copolymer is affected by the free proton and is dissolved in an alkaline aqueous solution or the like as compared with that before the action. Since it has a property of remarkably increasing the property and has good adhesion to a substrate, it is useful as a copolymer that can be suitably applied to various uses.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Osamu Konosu             5-8 Nishiomitabicho, Suita City, Osaka Prefecture             Within Nippon Shokubai (72) Inventor Tadayoshi Ugamura             5-8 Nishiomitabicho, Suita City, Osaka Prefecture             Within Nippon Shokubai F-term (reference) 4J100 AB07P AL03R AL08Q BA02P                       BA03P BA04P BA11P BA76P                       BC04Q BC08Q BC09Q BC53P                       CA05 CA06 JA24 JA39

Claims (3)

[Claims] 1. The following general formula (1); [Chemical 1] [In the formula, R¹, R^Three, R^FourAnd R⁶Are the same or different
Represents a hydrogen atom or a methyl group. R^TwoIs the carbon number
6 to 30 represents a substituted or unsubstituted alicyclic group. R ⁵Is
It represents a leaving group by a proton. a, b, c and d are
The repeating units (A), (B) in the copolymer,
The amount (mol%) of (C) and (D) is shown. ]]
The repeating unit (A), the repeating unit (D), and
A repeat unit (B) and / or a repeating unit (C) are required.
It has a proton-eliminating group characterized by
Copolymers. 2. The a is 5 to 30 mol%, and b +
c is 40 to 94 mol%, d is 1 to 30 mol%.
The copolymer having a proton-eliminating group according to claim 1. 3. The R ² is a cyclohexyl group, an isobornyl group or an adamantyl group, and the R ⁵ is t-.
The copolymer having a leaving group by a proton according to claim 1 or 2, which is a butyl group, a t-butoxycarbonyl group, a tetrahydropyranyl group or a trimethylsilyl group.