KR20150112884A - Production process of resist polymer and polymer used in the production process - Google Patents

Abstract

An object of the present invention is to provide a method for producing a resist polymer which can easily produce a polymer having excellent bridge defect control property of a resist composition with high reproducibility.
[MEANS FOR SOLVING PROBLEMS] The present invention relates to a process for producing a polymer composition comprising a first polymer having a structural unit having a first structure, a second polymer having a structural unit having a second structure and another structural unit and being different from the first polymer, And a step of bringing the first solvent into contact with a second solvent that does not dissolve the first solvent, wherein the first structure and the second structure are of the same kind. In the contacting step, it is preferable to bring the first composition containing the first polymer and the first solvent into contact with the second composition containing the second polymer and the second solvent. As the first structure and the second structure, a structure having polarity is preferable.

Description

TECHNICAL FIELD [0001] The present invention relates to a process for producing a resist polymer, and a polymer used in the process.

The present invention relates to a process for producing a resist polymer and a polymer used in the process.

A resist composition used in the production of various electronic devices such as semiconductor devices and liquid crystal devices generates an acid from the scattered organism in the exposed portion by irradiation with exposure light such as deep ultraviolet rays such as ArF excimer laser light and electron beams, The resist pattern is formed on the substrate by changing the dissolution rate of the exposed portion and the unexposed portion with respect to the developer.

Such a resist composition is required to be capable of forming a resist pattern having high resolution, excellent cross-sectional rectangular shape, and less bridge defects and the like. Regarding these requirements, various studies have been made on the structure and production method of the resist polymer contained in the resist composition. As such a resist polymer, for example, a polymer having a structural unit containing an acid-dissociable group, a structural unit containing a lactone structure such as a? -Butyrolactone structure, a structural unit containing a polar group such as a hydroxyl group, etc. is used (See Japanese Patent Application Laid-Open No. 2003-5375 and Japanese Patent Application Laid-Open No. 2008-83370). In such a resist polymer, these structural units may be biased and distributed in the polymer chain, which is considered to be one of the causes of defects in the resist pattern. As a method for producing a resist polymer that provides a resist composition excellent in suppressing bridge defect suppression by removing such a polymer, there has been studied a method of purifying a polymer using, for example, purifying particles or the like Japanese Patent Application Laid-Open No. 2007-19351). However, this method is troublesome because it is necessary to synthesize the purification particles, and the size, shape, specific surface area, etc. of the purification particles largely affect the purification effect, and therefore there is a problem that the reproducibility is low.

Japanese Patent Application Laid-Open No. 2003-5375 Japanese Patent Application Laid-Open No. 2008-83370 Japanese Patent Application Laid-Open No. 2007-19351

The present invention has been made based on the above-described circumstances, and an object of the present invention is to provide a process for producing a resist polymer which is capable of easily producing a polymer having excellent bridge defect controllability of a resist composition with high reproducibility.

The invention made to solve the above problem is a first polymer having a structural unit (hereinafter also referred to as " structural unit (I) ") comprising a first structure (hereinafter also referred to as & (Hereinafter, also referred to as "structural unit (i)") and a structural unit (also referred to as "structural unit (i)") containing a second structure (Hereinafter, also referred to as a " [C] solvent "), which is different from the first polymer (hereinafter also referred to as a "structural unit (ii)") (Hereinafter also referred to as " contact step ") in which the first solvent and the second solvent (hereinafter also referred to as " solvent D " ) And the structure (i) are the same.

Another invention made to solve the above problems is a polymer used in the process for producing a resist polymer, which is a polymer having a structural unit containing one structure and another structural unit.

Here, the "structure" included in the structural unit of the polymer means a certain range of atomic groups. In addition, the "same kind" of the above structures means that both structures are derived from the same kind of compound, and means, for example, that they have the same functional group. The "same" in the above structures means that both structures are derived from the same compound. The word " homologous " includes " the same ".

According to the method for producing a resist polymer of the present invention, a resist polymer excellent in the bridge defect suppressing property of a resist composition can be easily produced with high reproducibility. Further, the polymer of the present invention can be suitably used in the process for producing the polymer for resist. Therefore, they can be suitably used for a semiconductor device manufacturing process and the like, which are expected to progressively become finer thereafter.

≪ Method for producing resist polymer >

The method for producing the resist polymer includes a step of contacting the polymer [A], the polymer [B], the solvent [C] and the solvent [D] (hereinafter also referred to as a "contacting step"). According to this production method, a purified [A] polymer (hereinafter referred to as [A] polymer as a resist polymer) is obtained by subjecting a polymer [A] serving as a raw material for a resist polymer to purification treatment using a [B] ] Polymer ") is obtained.

In the polymer [A '] obtained by the above production method, the polymer in which the structural unit (I) containing the structural unit (I) is distributed rather than the raw material [A] Is considered to be reduced by adsorption or the like due to the high affinity with the [B] polymer having the unit (i). As a result, the resist composition using this [A '] polymer is excellent in bridge defect restraining property. In this production method, the purification treatment is carried out in a state in which the [A] polymer and the [B] polymer are dissolved or dispersed in a liquid phase containing a [C] solvent and a [D] solvent which are not mutually soluble. Therefore, the [A] polymer and the [B] polymer can be contacted more uniformly, and thus a resist polymer can be produced with high reproducibility. In addition, according to this production method, a resist polymer can be easily produced without complicated steps such as synthesis of particles for purification and the like.

It is preferable that the production method further comprises a step of separating the polymer [A '] from the mixture of the components [A] to [D] (hereinafter also referred to as a "separation step") after the contacting step. Further, before the contacting step, a step of synthesizing the [A] polymer and the [B] polymer (hereinafter also referred to as a "synthesis step") may be provided.

Each step will be described below.

<Synthesis Step>

In this step, the polymers [A] and [B] used in the production method are synthesized.

Hereinafter, each polymer and a method of synthesizing them will be described.

[[A] Polymer]

[A] Polymer is a polymer having a structural unit (I) containing the structure (I). This structure (I) is the same as the structure (i) of the [B] polymer. The polymer [A] preferably has a structural unit (hereinafter also referred to as &quot; structural unit (II) &quot;) containing an acid dissociable group to be described later and other structural units other than the structural unit (I) And may have a structural unit. The polymer [A] may have one structural unit or two or more structural units. The polymer [A] may have the structural unit (II) as the structural unit (I).

Hereinafter, each structural unit will be described.

[Structural unit (I)]

Structural unit (I) is a structural unit containing structure (I).

As the structure (I), for example,

A hydrocarbon structure such as a chain hydrocarbon structure, an alicyclic hydrocarbon structure, or an aromatic hydrocarbon structure;

A polar structure such as a lactone structure, a cyclic carbonate structure, a sultone structure, an amine structure, an alcohol structure, a phenol structure, a carboxylic acid structure, an amine structure, a ketone structure, an acyclic ester structure, an ether structure or a halogenated hydrocarbon structure .

Here, the chain hydrocarbon structure, alicyclic hydrocarbon structure and aromatic hydrocarbon structure refer to structures derived from chain hydrocarbons, alicyclic hydrocarbons and aromatic hydrocarbons, respectively. A lactone structure, a cyclic carbonate structure and a sultone structure each means a single ring (lactone ring) containing a group represented by -OC (O) -, a single ring containing a group represented by -OC (O) Refers to a structure having one ring (sultone ring) including a group represented by a ring (cyclic carbonate ring) and -OS (O) ₂ -. In addition, these rings are counted as the first ring, and in the case of only these rings, a monocyclic structure or a ring having another ring is referred to as a polycyclic structure regardless of its structure. The reduced number of these structures refers to the total number of atoms constituting the ring of these structures. An alcohol structure, a phenol structure, a carboxylic acid structure, an amine structure, a ketone structure, an acyclic ester structure and an ether structure are respectively -OH, -C ₆ H ₅ OH, -COOH, -NH ₂ or -NH-, -C (O) -, -C (O) -O-, and -O-. The halogenated hydrocarbon structure refers to a structure derived from a hydrocarbon substituted by a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Among them, a structure having polarity is preferable from the viewpoint that the affinity between the polymer [A] and the polymer [B] is higher, and a lactone structure, a cyclic carbonate structure, a sultone structure, an alcohol structure, a carboxylic acid structure, More preferably a lactone structure, a cyclic carbonate structure and an alcohol structure. [A] Since the polymer has the structural unit (I) comprising a structure having polarity, the resist composition containing the [A] polymer can improve the adhesion between the resist pattern and the substrate.

When the structure (I) is a lactone structure, a cyclic carbonate structure or a sultone structure, the lower limit of the reduced water of the structure (I) is preferably 5, more preferably 7, further preferably 8, desirable. By making the reduced amount of the structure (I) above the lower limit or higher, it becomes possible to produce the polymer [A '] more easily and with higher reproducibility. The upper limit of the reduced water is not particularly limited, but is preferably 20.

Examples of the structural unit containing a lactone structure include structural units represented by the following formulas.

In the above formula, R ^L1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

Examples of the structural unit containing a cyclic carbonate structure include structural units represented by the following formulas.

In the above formula, R ^L1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

Examples of the structural unit containing a sultone structure include structural units represented by the following formulas.

In the above formula, R ^L1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

Examples of the structural unit containing an alcohol structure include structural units represented by the following formulas.

In the above formula, R ^L2 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

As the structural unit (I), a structural unit containing a polar structure is preferable, and a structural unit containing a lactone structure, a structural unit containing a cyclic carbonate structure, a structural unit containing a sultone structure, Structural units containing a carboxylic acid structure, structural units containing an amine structure are more preferable, structural units containing a lactone structure, structural units containing a cyclic carbonate structure, More preferably a structural unit comprising a norbornane lactone structure, a structural unit comprising a 5-oxo-4- ^oxatricyclo [4.3.1.1 ^3,8 ] undecane structure, A structural unit containing a lactone structure, a structural unit containing an ethylene carbonate structure, and a structural unit containing an adamantanol structure are particularly preferable, and a norbornane (Meth) acrylate, a structural unit derived from norbornane lactone-2-yloxycarbonylmethyl (meth) acrylate, a structural unit derived from lactone- .1.1 ^3,8] undecane-2-yloxy Brassica Viterbo carbonyl methyl (meth) lactone as structural units, γ- butynyl derived from acrylate-yl (meth) acrylate structural unit derived from the ethylene carbonate- Structural units derived from monomethyl (meth) acrylate, and structural units derived from 3-hydroxyadamantan-1-yl (meth) acrylate are even more particularly preferred.

The content of the structural unit (I) is preferably from 10 mol% to 90 mol%, more preferably from 20 mol% to 80 mol%, and still more preferably from 30 mol% to 80 mol% based on the total structural units in the polymer [A] , More preferably 70 mol%, and particularly preferably 40 mol% to 60 mol%. By setting the content ratio of the structural unit (I) within the above range, the affinity between the polymer [A] and the polymer [B] can be increased, and the adhesion between the resist pattern formed on the resist composition and the substrate can be further improved have.

[Structural unit (II)]

The structural unit (II) is a structural unit containing an acid dissociable group. The term "acid dissociable group" refers to a group that substitutes a hydrogen atom such as a carboxyl group and is dissociated by the action of an acid. Since the polymer [A] has the structural unit (II), the resist composition has a difference in solubility in the developing solution between the exposed portion and the unexposed portion due to the acid generated by exposure, and as a result, a resist pattern can be formed .

As the structural unit (II), for example, a structural unit represented by the following formula (1) (hereinafter also referred to as "structural unit (II-1)") and the like can be mentioned.

In the above formula (1), R ¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y ¹ is a monovalent acid dissociable group.

As R ¹ , a hydrogen atom or a methyl group is preferable, and a methyl group is more preferable from the viewpoint of copolymerization of the monomer giving the structural unit (II-1).

The monovalent acid-dissociable group represented by Y ¹ is preferably a group represented by the following formula (Y-1).

In the above formula (Y-1), R ^e1 is a monovalent hydrocarbon group of 1 to 20 carbon atoms. R ^e2 and R ^e3 are each independently a monovalent straight chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms or a group represented by R ^e2 and R ^e3 , 20 &lt; / RTI &gt;

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, .

As the monovalent straight chain hydrocarbon group having 1 to 20 carbon atoms represented by R ^e1 , R ^e2 and R ^e3 , for example,

An alkyl group such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group and n-pentyl group;

Alkenyl groups such as an ethynyl group, a propenyl group, a butenyl group, and a pentenyl group;

An alkynyl group such as an ethynyl group, a propynyl group, a butynyl group and a pentynyl group.

Among these, an alkyl group is preferable, and an alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group, an ethyl group and an i-propyl group are more preferable, and an ethyl group is particularly preferable.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^e1 , R ^e2 and R ^e3 include, for example,

Monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cyclooctyl;

A cycloalkyl group such as a norbornyl group, an adamantyl group, a tricyclodecyl group, and a tetracyclododecyl group;

Monocyclic cycloalkenyl groups such as cyclopropenyl group, cyclobutenyl group, cyclopentenyl group and cyclohexenyl group;

Cycloalkenyl groups such as a norbornenyl group and a tricyclodecenyl group; and the like.

Of these, a monocyclic cycloalkyl group and a polycyclic cycloalkyl group are preferable, and a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group are more preferable.

As the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R ^e1 , for example,

Aryl groups such as phenyl, tolyl, xylyl, mesityl, naphthyl, methylnaphthyl, anthryl and methyl anthryl groups;

And aralkyl groups such as a benzyl group, a phenethyl group, a naphthylmethyl group, and an anthrylmethyl group.

Examples of the alicyclic structure having 3 to 20 carbon atoms represented by these groups combined with the carbon atoms to which they are bonded are, for example,

Monocyclic cycloalkane structures such as a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, and a cyclooctane structure;

A polycyclic cycloalkane structure such as a norbornane structure, an adamantane structure, a tricyclodecane structure, and a tetracyclododecane structure;

Monocyclic cycloalkene structures such as a cyclopropene structure, a cyclobutene structure, a cyclopentene structure, a cyclohexene structure, and a cyclooctene structure;

And a polycyclic cycloalkene structure such as a norbornene structure, a tricyclodecene structure, and a tetracyclododecene structure.

Among them, a monocyclic cycloalkane structure and a polycyclic cycloalkane structure are preferable, and a monocyclic cycloalkane structure having 5 to 8 carbon atoms and a polycyclic cycloalkane structure having 7 to 12 carbon atoms are more preferable, and a cyclopentane structure, a cyclohexane structure , A cyclooctane structure, a norbornane structure and an adamantane structure are more preferable, and a cyclopentane structure and an adamantane structure are particularly preferable.

Examples of the structural unit (II-1) include structural units represented by the following formulas (1-1) to (1-8).

In the above formulas (1-1) to (1-8), R ¹ is the same as in the above formula (1). R ^e1 , R ^e2 and R ^e3 are synonymous with the above formula (Y-1). r is independently an integer of 1 to 3;

The structural unit (II-1) is preferably a structural unit represented by the above formulas (1-2), (1-3), (1-5) and (1-6) , More preferably a structural unit represented by the above formula (1-3) wherein r is 1, more preferably a structural unit represented by the above formula (1-3) wherein r is 1 and R ^e1 is an ethyl group. Is particularly preferred.

The content of the structural unit (II) is preferably 10% by mole to 90% by mole, more preferably 20% by mole to 80% by mole, and still more preferably 30% by mole to all structural units constituting the polymer [A] , More preferably 70 mol%, and particularly preferably 40 mol% to 60 mol%. By setting the content ratio of the structural unit (II) within the above range, the resist composition can further improve the pattern formability.

[Other structural units]

The polymer [A] may have other structural units other than the structural unit (I) and the structural unit (II). The above other structural units are those having no [B] polymer among the structural units having the same structure as the structure (I) of the [A] polymer. Examples of the other structural unit include structural units including the structure exemplified as the structural unit (I). The content of the other structural units is preferably 20 mol% or less, more preferably 10 mol% or less, based on the total structural units constituting the polymer [A].

The polystyrene-reduced weight average molecular weight (Mw) of the polymer [A] by GPC (Gel Permeation Chromatography) is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, still more preferably 3,000 to 20,000, Particularly preferred. If the Mw of the polymer [A] is less than the lower limit described above, the heat resistance of the resist pattern formed of the resist composition may be lowered. If the Mw of the polymer [A] exceeds the upper limit, there is a fear that the developability of the resist composition is lowered.

The ratio (Mw / Mn, degree of dispersion) of the polymer [A] to the polystyrene reduced number average molecular weight (Mn) by GPC is preferably 1 to 5, more preferably 1 to 3, More preferably 1 to 2, particularly preferably.

[[B] polymer]

The polymer [B] has a structural unit (i) containing the structure (i) and a structural unit (ii), and is a polymer different from the polymer [A]. This structure (i) is the same as the structure (I) of the polymer [A]. When the [B] polymer is used in the process for producing a resist polymer, the [B] polymer has a structural unit (i), so that it can interact with the polymer in which the structural unit (I) As a result, it is considered that such a polymer can be removed by adsorption or the like. In addition, the [B] polymer has the structural unit (ii), which makes it possible to exist in a liquid phase different from the [A] polymer. As a result, the structural unit (I) The polymer can be removed from the [A] polymer, and the obtained [A '] polymer and the obtained [B] polymer can be separated.

The polymer [B] may have other structural units other than the structural unit (i) and the structural unit (ii). The polymer [B] may have one or more of these structural units.

Hereinafter, each structural unit will be described.

[Structural unit (i)]

Structural unit (i) is a structural unit containing structure (i). This structure (i) is the same as the structure (I) of the polymer [A].

The structure (i) in the structural unit (i) is preferably the same as the structure (I) in the structural unit (I). By the same structure (i) and structure (I), it is considered that the polymer in which the structural unit (I) in the polymer [A] is biased and distributed can be more effectively removed.

The content of the structural unit (i) is preferably 1 mol% to 30 mol%, more preferably 2 mol% to 25 mol%, and still more preferably 3 mol%, based on the total structural units constituting the polymer [B] To 20 mol%, and particularly preferably from 5 mol% to 15 mol%. By setting the content ratio of the structural unit (i) within the above range, the affinity between the polymer [A] and the polymer [B] and the distribution of the polymer [B] to the solvent [C] and [D] As a result, it is considered that the polymer in which the structural unit (I) in the polymer [A] is biased and distributed can be more effectively removed.

[Structural unit (ii)]

The structural unit (ii) is a structural unit other than the structural unit (i). The structural unit (ii) is not particularly limited as long as it is other than the structural unit (i). For example, the structural unit (i) includes a third structure (hereinafter referred to as structure (iii)) having a higher polarity than the structure ), A structural unit containing a structure having a lower polarity than the structure (i) contained in the structural unit (i), and the like.

Examples of the structure (iii) include a lactam structure (cyclic amide structure), a cyclic amide structure, a urea structure, a carbamate structure, an alcohol structure, an amine structure, a thiol structure, a sulfonic acid structure, Structure and the like.

Examples of the structure having a low polarity include a hydrocarbon structure, a ketone structure, and an ether structure.

The content ratio of the structural unit (ii) is preferably from 70 mol% to 99 mol%, more preferably from 75 mol% to 98 mol%, still more preferably from 80 mol% to 98 mol%, based on the total structural units constituting the [B] More preferably 97 mol%, and particularly preferably 85 mol% to 95 mol%. By setting the content ratio of the structural unit (ii) within the above range, it is possible to make the [B] polymer exist in a liquid phase different from the [A] polymer. As a result, the structural unit (I) Can be removed from the polymer [A], and it becomes possible to separate the polymer from the obtained [A '] polymer.

The weight average molecular weight (Mw) of the [B] polymer in terms of polystyrene calculated by GPC is not particularly limited, but is preferably 500 or more and 50,000 or less, more preferably 600 or more and 20,000 or less, still more preferably 700 or more and 10,000 or less, Particularly preferably 6,000 or less, more preferably 1,000 or more and 3,000 or less. By setting the Mw of the [B] polymer in the above range, the [B] polymer can be further present in a liquid phase different from the [A] polymer. As a result, the structural unit (I) The distributed polymer can be further removed from the [A] polymer, and further separation with the obtained [A '] polymer becomes possible.

The ratio (Mw / Mn) of the polymer [B] to the number average molecular weight (Mn) converted to polystyrene by the GPC is usually 1 to 5, preferably 1 to 4, More preferably 1 or more and 2 or less.

[Method of synthesizing [A] polymer and [B] polymer]

[A] Polymer and [B] polymer can be synthesized according to a conventional method such as radical polymerization. For example, (1) a method in which a solution containing a monomer and a radical initiator is added dropwise to a solution containing a reaction solvent or a monomer to cause a polymerization reaction, (2) a method in which a solution containing a monomer and a solution containing a radical initiator are separately (3) a method in which a solution containing plural kinds of monomers and a solution containing a radical initiator are separately added dropwise to a solution containing a reaction solvent or a monomer, and (4) a method in which a solution containing a monomer and a radical initiator is subjected to a polymerization reaction in the absence of a solvent or in a reaction solvent.

When the monomer solution is dropped and reacted with the monomer solution, the amount of the monomer in the monomer solution to be added is preferably at least 30 mol%, more preferably at least 50 mol%, based on the total amount of the monomers used in the polymerization, More preferably 70 mol% or more.

The reaction temperature in these methods may be appropriately determined depending on the initiator species. It is usually 30 to 150 ° C, preferably 40 to 150 ° C, and more preferably 50 to 140 ° C. The dropping time is usually from 30 minutes to 8 hours, preferably from 45 minutes to 6 hours, more preferably from 1 hour to 5 hours, depending on the reaction temperature, the kind of initiator, and the conditions of the monomer to be reacted. The total reaction time including the dropping time is also preferably 30 minutes to 12 hours, more preferably 45 minutes to 12 hours, and even more preferably 1 to 10 hours, depending on the conditions like the dropping time.

Examples of the radical initiator used in the polymerization include azobisisobutyronitrile (AIBN), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'- Azobis (2-cyclopropylpropionitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate) Azo type radical initiators such as 2'-azobisisobutyrate; Peroxide radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide and the like. Of these, AIBN and dimethyl 2,2'-azobis (2-methylpropionate) are preferred. The radical initiator may be used alone or in combination of two or more.

As the reaction solvent, a solvent other than the polymerization inhibiting solvent (nitrobenzene having polymerization inhibiting effect, mercapto compound having chain transfer effect, etc.), and a solvent capable of dissolving the monomer can be used. Examples thereof include alcohols, ethers, ketones, amides, esters, lactones, nitriles and mixed solvents thereof. These solvents may be used alone or in combination of two or more.

The polymer obtained by the polymerization reaction is preferably recovered by the reprecipitation method. That is, after completion of the polymerization reaction, the polymer solution is put in a re-precipitation solvent to recover the desired polymer as a powder. As the re-precipitation solvent, alcohols, alkanes, etc. may be used alone or in combination of two or more kinds. In addition to the repulse method, the polymer may be recovered by removing low-molecular components such as monomers and oligomers by liquid separation, column operation, ultrafiltration, or the like.

Next, using the synthesized [A] polymer and [B] polymer, the contact step is carried out.

<Contact Process>

In this step, the polymer [A], the polymer [B], the solvent [C] and the solvent [D] are brought into contact.

The [C] solvent and the [D] solvent used in the present step are not particularly limited as long as they do not dissolve each other, and can be appropriately selected from the solvents exemplified as the [H] solvent of the resist composition to be described later. The term &quot; not mutually dissolving &quot; includes not only completely dissolving each other, but also forming two liquid phases when a part of them is dissolved with each other. As the [A] polymer and the [B] polymer, one type or two or more types may be used. The [C] solvent and the [D] solvent may be used alone or in combination of two or more. The polymer [A] and the polymer [B] may be dissolved in the liquid phase or may not be dissolved in the liquid phase but may be dispersed, but they are preferably dissolved from the viewpoint of more uniform contact.

The method of contacting the components [A] to [D] is not particularly limited and includes, for example, (1) a method of mixing the polymer [A], the polymer [B], the solvent [C] , (2) a method in which [A] a polymer and a [B] polymer are added to a liquid phase containing a [C] solvent and a [D] To the liquid phase containing the [C] solvent and the [D] solvent, and (4) a method of adding the polymer [A] to the liquid phase containing the [C] solvent and the [D] A method in which [B] a polymer is added and mixed, (5) a method in which a polymer [B] is added to a liquid phase containing a [C] solvent and a [D] A method in which the polymer [A] is added to the [C] solvent and mixed, and the mixture of the [B] polymer and the [D] solvent is mixed, followed by mixing the two mixtures.

The amount of the polymer [A] used is preferably 1 part by mass to 50 parts by mass, more preferably 2 parts by mass to 30 parts by mass, and more preferably 3 parts by mass, per 100 parts by mass of the total of the [C] To 20 parts by mass is more preferable.

The amount of the [B] polymer to be used is preferably 0.1 part by mass to 5 parts by mass, more preferably 0.2 parts by mass to 3 parts by mass, and more preferably 0.3 part by mass, per 100 parts by mass of the total of the [C] To 2 parts by mass is more preferable.

The amount of the polymer [A] used is preferably 1 part by mass to 50 parts by mass, more preferably 3 parts by mass to 30 parts by mass, further preferably 5 parts by mass to 20 parts by mass, per 100 parts by mass of the polymer [B] .

The amount of the [C] solvent to be used is preferably 20 parts by mass to 500 parts by mass, more preferably 30 parts by mass to 300 parts by mass, further preferably 50 parts by mass to 200 parts by mass, per 100 parts by mass of the [D] , And particularly preferably from 75 parts by mass to 150 parts by mass.

The time for contacting the components [A] to [D] in the contacting step is preferably 10 seconds to 10 hours, more preferably 1 minute to 5 hours, still more preferably 5 minutes to 2 hours, Min to 1 hour is particularly preferable.

The temperature of the components [A] to [D] in the contacting step is preferably 5 ° C to 90 ° C, more preferably 10 ° C to 70 ° C, further preferably 15 ° C to 50 ° C, 40 DEG C is particularly preferable.

As the method of bringing the components [A] to [D] into contact with each other, the above-mentioned (6) is preferable from the viewpoint of more effective dissolution and contact. This method comprises the steps of mixing a first composition containing a [A] polymer and a [C] solvent (hereinafter also referred to as a &quot; composition (I) &quot;) with a second composition containing a [B] (Hereinafter also referred to as &quot; composition (II) &quot;).

In this method, the structure (iii) having a polarity higher than that of the structure (ii) in the structural unit (ii) of the [B] polymer and the polarity of the [D] solvent higher than the polarity of the [C] desirable. By doing so, the affinity of the [A] polymer to the [C] solvent and the [B] polymer to the [D] solvent becomes higher, so that the polymer [A] and the polymer [B] , And as a result, the [A '] polymer can be more easily separated in the separation step after the contact process.

Examples of the structure (iii) include the structures exemplified in the above-mentioned [B] polymer, but among them, a polarity difference between the [B] polymer and the [A] polymer is increased by having a higher polarity, The lactam structure is preferable. As the lactam structure, a γ-butyrolactam structure, a δ-valerolactam structure, and an ε-caprolactam structure are preferable, and a γ-butyrolactam structure is more preferable.

As the [C] solvent, an organic solvent is preferable, a ketone solvent is more preferable, a ketone solvent having 4 to 6 carbon atoms is more preferable, and methyl isobutyl ketone is particularly preferable. As the [D] solvent, a solvent containing water is preferable, water is more preferable, and distilled water is more preferable. By using such a combination of solvents, both the contact between the [A] polymer and the [B] polymer and the subsequent separation can be performed more effectively.

The concentration of the polymer [A] in the composition (1) is preferably from 1% by mass to 30% by mass, more preferably from 3% by mass to 20% by mass, and further preferably from 5% by mass to 15% .

The concentration of the [B] polymer in the composition (2) is preferably 0.1% by mass to 10% by mass, more preferably 0.3% by mass to 5% by mass, and still more preferably 0.5% by mass to 3% .

The amount of the composition (1) to be used is preferably 20 parts by mass to 500 parts by mass, more preferably 30 parts by mass to 300 parts by mass, further preferably 50 parts by mass to 200 parts by mass, per 100 parts by mass of the composition (2) , And particularly preferably from 75 parts by mass to 150 parts by mass.

The method for making the contact is not particularly limited, and examples thereof include a method of stirring in a container, a tank or the like. By stirring, the components [A] to [D] can be effectively contacted.

As the material of the container and the like, it is preferable that it is easy to handle and impurities are difficult to be mixed, and examples thereof include glass, resin, stainless steel and the like. As the shape of the container or the like, a shape capable of easily stirring by adding the [A] to [D] components is preferable, and for example, a cylindrical shape and the like can be mentioned. Examples of the stirring method include a method of rotating a stirring blade such as a rod, a plate, or a propeller through a rotating shaft with a motor or the like.

<Separation Process>

In this step, the polymer [A '] produced in the contacting step is separated from the mixture of the components [A] to [D].

For example, in the case where the [A '] polymer and the [B] polymer are dissolved in different liquid phases, the [A'] polymer is dissolved by liquid separation or the like And the solvent is distilled off from the recovered liquid phase, reprecipitation, column operation, ultrafiltration or the like is carried out to obtain the polymer [A '].

As described above, according to the process for producing a resist polymer, a resist polymer can be easily produced with high reproducibility. Using the resulting resist polymer, for example, the following resist compositions can be produced. The obtained resist composition is excellent in bridge defects suppressing property.

&Lt; Resist composition &

The resist composition contains the polymer [A '], and the [E] radiation-sensitive acid generator (hereinafter also referred to as the "[E] acid generator" Polymer (hereinafter also referred to as a "[G] polymer") and a [H] solvent, and may contain other components than the above components.

Hereinafter, each component constituting each resist composition and a method for producing the resist composition will be described.

[[A '] polymer]

[A '] The polymer is obtained by carrying out the contacting step and the separation step from the [A] polymer as described above. It is considered that in the [A '] polymer, the polymer in which the structural unit (I) is biased and distributed is lower than that in the [A] polymer.

[[E] acid generator]

[E] The acid generator is a substance which generates an acid upon exposure. The resulting acid dissociates the acid-dissociable group of the [A '] polymer or the like to generate a carboxyl group or the like, and the solubility of these polymers in the developer is changed, so that a resist pattern can be formed from the resist composition.

Examples of the [E] acid generator include an onium salt compound, an N-sulfonyloxyimide compound, a halogen-containing compound, and a diazoketone compound.

Examples of the onium salt compound include a sulfonium salt, a tetrahydrothiophenium salt, an iodonium salt, a phosphonium salt, a diazonium salt, and a pyridinium salt.

Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium 4- (adamantan-1-ylcarbonyloxy) butane- 1,1,2-trifluorobutane-1-sulfonate, and the like.

Examples of the tetrahydrothiophenium salt include 4-hydroxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-hydroxy-1-naphthyltetrahydrothiophenium nonafluoro-n-butane Sulfonate and the like.

Examples of the iodonium salt include diphenyl iodonium trifluoromethanesulfonate, diphenyl iodonium nonafluoro-n-butanesulfonate, and the like.

As the [E] acid generator, an onium salt compound is preferable, a sulfonium salt is more preferable, a triphenylsulfonium salt is more preferable, and triphenylsulfonium 4- (adamantan-1-ylcarbonyloxy ) Butane-1,1,2-trifluorobutane-1-sulfonate is particularly preferred.

The content of the [E] acid generator is preferably 0.2 parts by mass to 30 parts by mass, more preferably 0.5 parts by mass to 20 parts by mass, further preferably 1 part by mass to 15 parts by mass And particularly preferably 2 parts by mass to 10 parts by mass. [E] The acid generator may be used alone or in combination of two or more.

[[F] acid diffusion control agent]

The resist composition may contain, if necessary, [F] acid diffusion control agent. [F] acid diffusion control agent controls the diffusion phenomenon of an acid generated from the acid generator [E] by exposure to a resist film, and exhibits an effect of suppressing an undesirable chemical reaction in a non-exposed region do.

Examples of the [F] acid diffusion control agent include compounds represented by the following formula (2) (hereinafter also referred to as "nitrogen-containing compound (I)"), compounds having two nitrogen atoms in the same molecule Nitrogen-containing compound (III) "), amide group-containing compound, urea compound, nitrogen-containing heterocyclic compound, and the like have.

In the above formula (2), R ² , R ³ and R ⁴ are each independently a hydrogen atom, an optionally substituted straight chain, branched or cyclic alkyl group, an aryl group or an aralkyl group.

Examples of the nitrogen-containing compound (I) include monoalkyl amines such as n-hexylamine; Dialkylamines such as di-n-butylamine; Trialkylamines such as triethylamine; And aromatic amines such as aniline.

Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ', N'-tetramethylethylenediamine and the like.

Examples of the nitrogen-containing compound (III) include polyamine compounds such as polyethyleneimine and polyallylamine; And polymers such as dimethylaminoethyl acrylamide.

Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide and the like.

Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,3-diphenylurea and tributylthiourea.

As the nitrogen-containing heterocyclic compound, for example, pyridine such as pyridine or 2-methylpyridine; Morpholines such as N-propylmorpholine and N- (undecylcarbonyloxyethyl) morpholine; Pyrazine, and pyrazole.

As the nitrogen-containing organic compound, a compound having an acid-dissociable group may also be used. Examples of the nitrogen-containing organic compound having such an acid dissociable group include N- (t-butoxycarbonyl) dicyclohexylamine, N- (t-butoxycarbonyl) diphenylamine, Nt-butoxycar 4-hydroxypiperidine, N- (t-amyloxycarbonyl) -4-hydroxypiperidine, and the like.

As the [F] acid diffusion controlling agent, a compound having an acid-dissociable group is preferable, and N- (t-amyloxycarbonyl) -4-hydroxypiperidine is more preferable.

The content of the [F] acid diffusion controlling agent is preferably 0 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, further preferably 0.3 to 10 parts by mass, relative to 100 parts by mass of the [A '] polymer Do. If the content of the [F] acid diffusion control agent exceeds the upper limit, the sensitivity of the resist composition may be lowered.

[[G] polymer]

The [G] polymer is a polymer containing a fluorine atom (except that [A '] corresponds to a polymer). The resist composition further contains the [G] polymer in addition to the [A '] polymer, whereby the [G] polymer is uniformalized on the surface layer of the formed resist film, and as a result, the hydrophobicity of the resist film surface can be improved. As a result, when the liquid immersion lithography is performed, the contact angle of the resist film and the liquid immersion liquid can be sufficiently increased, and the scanning speed can be further increased.

The [G] polymer preferably has a structural unit represented by the following formula (3) (hereinafter also referred to as "structural unit (f)"). Further, the [G] polymer may have a structural unit other than the structural unit (f). Further, the [G] polymer may contain one structural unit or two or more structural units. Hereinafter, each structural unit will be described.

[Structural unit (f)]

The structural unit (f) is a structural unit represented by the following formula (3).

In the above formula (3), R ^f1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^f2 is a substituted or unsubstituted monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms or a substituted or unsubstituted monovalent fluorinated alicyclic hydrocarbon group having 4 to 20 carbon atoms.

Examples of the monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms include a fluoromethyl group, a trifluoromethyl group, and a trifluoroethyl group.

Examples of the monovalent fluorinated alicyclic hydrocarbon group having 4 to 20 carbon atoms include a fluorocyclopentyl group, a difluorocyclopentyl group, a cyclopentyldifluoropropyl group, a perfluorocyclohexyl group, and the like .

Examples of the monomer giving the structural unit (f) include monomers such as trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) And perfluoro n-propyl (meth) acrylate.

As the structural unit (f), a structural unit represented by the following general formula (3-1) and a structural unit represented by (3-2) are preferable.

In the formulas (3-1) and (3-2), R ^f1 is as defined in the above formula (3).

Among them, the structural unit represented by the above formula (3-1) is preferable.

The content of the structural unit (f) is preferably from 10 mol% to 70 mol%, and more preferably from 20 mol% to 50 mol%, based on the total structural units constituting the [G] polymer.

The [G] polymer may contain other structural units other than the structural unit (f). Examples of the other structural unit include a structural unit (II) of the polymer [A] and the like.

The content ratio of the other structural units is preferably from 5 mol% to 90 mol%, more preferably from 10 mol% to 80 mol%, still more preferably from 20 mol% to 80 mol%, with respect to the total structural units constituting the [G] More preferably 70 mol%.

The content of the [G] polymer is preferably 20 parts by mass or less, more preferably 0.1 parts by mass to 15 parts by mass, further preferably 1 part by mass to 10 parts by mass, more preferably 1 part by mass, per 100 parts by mass of the [A ' Mass part to 6 mass part is particularly preferable. If the content of the [G] polymer exceeds the upper limit, the water repellency of the surface of the resist film becomes excessively high, and development defects may occur.

The fluorine atom content of the [G] polymer is preferably larger than the fluorine atom content of the [A '] polymer. If the content of fluorine atoms in the [G] polymer is larger than that of the polymer [A '], the [G] polymer can be more effectively uniformalized to the surface layer of the resist film and the resist [A'] containing the polymer [ The water repellency of the resist film surface formed by the composition can be further improved. The difference between the fluorine atom content of the [G] polymer and the fluorine atom content rate of the [A '] polymer is preferably 1% by mass or more, and more preferably 3% by mass or more.

The fluorine atom content of the [G] polymer is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and particularly preferably 10% by mass or more.

The fluorine atom content (% by mass) can be calculated from the structure of the polymer by ¹³ C-NMR.

The [G] polymer can be synthesized in the same manner as the [A] polymer described above.

The weight average molecular weight (Mw) of the [G] polymer as determined by GPC in terms of polystyrene is not particularly limited, but is preferably 1,000 or more and 50,000 or less, more preferably 2,000 or more and 30,000 or less, still more preferably 2,500 or more and 20,000 or less, 15,000 is particularly preferred. When the Mw of the [G] polymer is within the above range, the coating property of the resist composition and the ability to inhibit development defects are improved. If the Mw of the [G] polymer is less than the lower limit described above, a resist film having sufficient heat resistance may not be obtained. If the Mw of the [G] polymer exceeds the upper limit, the developability of the resist film may be lowered.

The ratio (Mw / Mn) of the [G] polymer to the polystyrene reduced number average molecular weight (Mn) by GPC is usually 1 to 5, preferably 1 to 3, more preferably 1 to 2 desirable.

[[H] Solvent]

The [H] solvent is a component for dissolving or dispersing the [A '] polymer and other components. The [H] solvent may be used alone or in combination of two or more.

Examples of the [H] solvent include an alcohol-based solvent, an ether-based solvent, a ketone-based organic solvent, an ester-based organic solvent, and a hydrocarbon-based solvent.

As the alcoholic solvent, for example,

Aliphatic monoalcohol solvents having 1 to 18 carbon atoms such as 4-methyl-2-pentanol and n-hexanol;

Alicyclic monoalcohol solvents having 3 to 18 carbon atoms such as cyclohexanol;

Polyhydric alcohol solvents having 2 to 18 carbon atoms such as 1,2-propylene glycol;

And polyhydric alcohol partial ether solvents of 3 to 19 carbon atoms such as propylene glycol monomethyl ether.

As the ether-based solvent, for example,

Dialkyl ether solvents such as diethyl ether and dipropyl ether;

Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;

Containing ether solvents such as diphenyl ether and anisole, and the like.

Examples of the ketone solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone and diethyl ketone,

Cyclic ketone solvents such as cyclopentanone, cyclohexanone, and cycloheptanone;

2,4-pentanedione, acetonyl acetone, acetophenone, and the like.

As the ester-based solvent, for example,

Monocarboxylic acid ester-based solvents such as n-butyl acetate and ethyl lactate;

Polyhydric alcohol partial ether carboxylate type solvents such as propylene glycol monomethyl ether acetate;

and lactone solvents such as? -butyrolactone and? -valerolactone.

As the hydrocarbon-based solvent, for example,

aliphatic hydrocarbon solvents having 5 to 12 carbon atoms such as n-pentane and n-hexane;

And aromatic hydrocarbon solvents having 6 to 16 carbon atoms such as toluene and xylene.

The [H] solvent is preferably a ketone solvent or an ester solvent. As the ketone-based solvent, a cyclic ketone-based solvent is more preferable, and cyclohexanone is more preferable. As the ester-based solvent, a polyhydric alcohol partial ether carboxylate-based solvent and a lactone-based solvent are more preferable, and propylene glycol monomethyl ether acetate and -butyrolactone are more preferable.

[Other components]

The resist composition may contain other components such as a surfactant, an alicyclic skeleton-containing compound, and a sensitizer in addition to the above components. The other components may be used alone or in combination of two or more. The content of other components can be appropriately determined according to the purpose.

[Method of producing resist composition]

The resist composition is prepared by mixing the [A '] polymer and, if necessary, the components such as the acid generator and the [H] solvent at a predetermined ratio, and preferably the obtained mixed solution is filtered through a membrane filter For example, by filtration.

The solid content concentration of the resist composition is preferably 0.1% by mass to 50% by mass, more preferably 0.5% by mass to 30% by mass, still more preferably 1% by mass to 10% by mass.

Using the obtained resist composition, a resist pattern can be formed by, for example, the following method for forming a resist pattern. The resulting resist pattern has reduced bridge defects.

<Method of Forming Resist Pattern>

The resist pattern forming method includes a step of forming a resist film (hereinafter also referred to as a resist film forming step), a step of exposing the resist film (hereinafter also referred to as an &quot; exposure step &quot;), and a step of developing the exposed resist film , &Quot; development process &quot;).

Each step will be described below.

(Resist film forming step)

In this step, a resist film is formed by using the above-mentioned resist composition. The application method is not particularly limited, but suitable application means such as rotational application, casting application, roll application, etc. can be adopted. Examples of the substrate include silicon wafers, wafers coated with aluminum, and the like. Specifically, a resist composition is applied so that the obtained resist film has a predetermined thickness, and then PB is pre-baked if necessary to volatilize the solvent in the coating film. The temperature of PB is usually 60 to 140 占 폚, preferably 80 to 120 占 폚. The PB time is usually 5 seconds to 600 seconds, preferably 10 seconds to 300 seconds. The film thickness of the obtained resist film is preferably 10 nm to 500 nm.

(Exposure step)

In this step, the resist film formed in the resist film forming step is exposed. This exposure is carried out, in some cases, by irradiating the radiation through a mask having a predetermined pattern through an immersion medium such as water. Examples of the radiation include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, EUV (wavelength 13.5 nm), X-rays, and? -Rays depending on the line width of a target pattern; Electron beam, charged particle beam such as? -Ray, and the like.

It is also preferable to perform post exposure bake (PEB) after exposure. By conducting PEB, the dissociation reaction of the acid dissociable group at the exposed part of the resist film can be smoothly proceeded. The temperature of the PEB is usually 50 to 180 占 폚, preferably 80 to 130 占 폚. The PEB time is usually 5 seconds to 600 seconds, preferably 10 seconds to 300 seconds.

(Developing step)

In this step, the exposed resist film is developed in the above exposure step. Examples of the developer used in this development include an alkali developing solution and an organic solvent developing solution. As a result, a predetermined resist pattern is formed.

As the alkali developer, for example, at least one of alkaline compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, tetramethylammonium hydroxide (TMAH), pyrrole and piperidine And an alkaline aqueous solution prepared by dissolving or dispersing the above components.

As the organic solvent developing solution, for example,

Alcohol solvents such as methanol, ethanol and n-propanol;

Ether solvents such as diethyl ether, dipropyl ether and dibutyl ether;

Ketone solvents such as acetone, methyl ethyl ketone and methyl-n-propyl ketone;

Amide solvents such as N, N'-dimethylimidazolidinone and N-methylformamide;

Isopropyl acetate, n-butyl acetate and the like.

These developers may be used alone or in combination of two or more. After development, it is common to wash with water or an alcohol-based solvent and dry.

<Polymer>

The polymer of the present invention is a polymer used in the process for producing the resist polymer, and is characterized by having a structural unit containing one structure and another structural unit.

In addition, it is preferable that the other structural unit includes a structure higher than the one structure.

Since such a polymer has the above structure, it can be suitably used in the above-mentioned method for producing a resist polymer. The polymer is described in the section [B] polymer described above.

[Example]

Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. Each physical property measurement in the examples was carried out by the following method.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)] [

([A] polymer and [G] polymer)

The Mw and Mn in the polymer [A] and the polymer [G] were measured using a GPC column (two "G2000HXL", one "G3000HXL" and one "G4000HXL" manufactured by Tosoh Corporation) at a flow rate of 1.0 milliliter / Eluting solvent: tetrahydrofuran, column temperature: 40 占 폚, using GPC with monodisperse polystyrene as the standard. The degree of dispersion (Mw / Mn) was calculated from the results of measurement of Mw and Mn.

([B] polymer)

The Mw and Mn in the polymer [B] were measured using a GPC column (two "G2000HXL", one "G3000HXL" and one "G4000HXL" manufactured by Tosoh Corporation) at a flow rate of 1.0 milliliter / (Concentration of triethylamine: 0.3% by mass), column temperature: 40 占 폚, and by GPC using monodispersed polystyrene as a standard. The degree of dispersion (Mw / Mn) was calculated from the results of measurement of Mw and Mn.

[ ¹³ C-NMR analysis]

(Mol%) of each structural unit in each polymer was determined using a nuclear magnetic resonance apparatus ("JNM-ECX400" manufactured by Nihon Denshi Co., Ltd.) using CDCl ₃ or DMSO-d ₆ as a measurement solvent Analysis was carried out.

<Synthesis of [A] Polymer, [B] Polymer and [G] Polymer>

The monomers used for the synthesis of each polymer are shown below.

[Synthesis of [A] Polymer]

[Synthesis Example 1] [Synthesis of polymer (A-1)] [

549.42 g (50 mol%) of the compound (M-2) and 450.58 g (50 mol%) of the compound (M-9) were dissolved in 2,300 g of 2-butanone and 40.60 g of AIBN as a radical polymerization initiator 5 mol% based on the total) was further dissolved to prepare a monomer solution. Then, a 5 L three-necked flask charged with 700 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction kettle was heated to 80 DEG C with stirring, and the monomer solution prepared was added dropwise over 3 hours using a dropping funnel. The start of dropwise addition was defined as the polymerization initiation time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization reaction solution was cooled to 30 캜 or lower by water-cooling, and then charged into 20 kg of methanol. The precipitated white powder was filtered off. The obtained white powder was washed with 4 kg of methanol twice, filtered and dried under reduced pressure at 60 캜 for 15 hours to obtain a white powdery polymer (A-1) (yield: 710 g, yield: 71% ). The polymer (A-1) thus obtained had an Mw of 6,400 and an Mw / Mn of 1.5. As a result of ¹³ C-NMR analysis, the content ratios of the respective structural units derived from (M-2) and (M-9) were 42.1 mol% and 57.9 mol%, respectively.

[Synthesis Examples 2 to 6] [Synthesis of Polymers (A-2) to (A-6)

Each of the polymers was synthesized in the same manner as in Synthesis Example 1 except that the compound of the kind and amount shown in Table 1 below was used. The total mass of the compound used was 1,000 g. Mw, Mw / Mn and content ratio (mol%) of each structural unit of the synthesized polymer are shown in Table 1 below. &Quot; - &quot; in Table 1 indicates that the corresponding component was not used.

[Synthesis of [B] polymer]

[Example 1] [Synthesis of polymer (B-1)] [

44.55 g (70 mol%) of the compound (M-1) and 12.73 g (10 mol%) of the compound (M-2) were dissolved in 490 g of propylene glycol monomethyl ether and 4.70 g of AIBN as a radical polymerization initiator 5 mol% based on the total) was further dissolved to prepare a monomer solution. Next, a 1 L three-necked flask charged with 12.73 g (20 mol%) of the compound (M-1) and 210 g of propylene glycol monomethyl ether was purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction kettle was heated to 80 DEG C with stirring, and the monomer solution prepared was added dropwise over 3 hours using a dropping funnel. The start of dropwise addition was defined as the polymerization initiation time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization reaction solution was concentrated until the weight of the polymerization reaction solution became 210 g, and then the concentrate was slowly added to 1,050 g of n-hexane to precipitate a solid component. The liquid mixture was decanted to remove the liquid and the solid was washed three times with 210 g of n-hexane. The obtained solid was dried under reduced pressure at 60 DEG C for 15 hours to obtain a polymer (B-1) (yield: 56 g , Yield 80%). The polymer (B-1) thus obtained had Mw of 1,200 and Mw / Mn of 2.4. As a result of ¹³ C-NMR analysis, the content ratios of the respective structural units derived from (M-1) and (M-2) were 90.8 mol% and 9.2 mol%, respectively.

[Examples 2 to 6] [Synthesis of polymers (B-2) to (B-6)] [

Each of the polymers was synthesized in the same manner as in Example 1, except that the compound of the kind and amount shown in Table 2 below was used. The total mass of the compound used was 70 g. Mw, Mw / Mn and content ratio (mol%) of each structural unit of the synthesized polymer are shown in Table 2 below. &Quot; - &quot; in Table 2 indicates that the corresponding component was not used.

[Synthesis Example 7] [Synthesis of polymer (b-1)] [

0.60 g of polyvinyl alcohol (average degree of polymerization 1,500 to 1,800) and 200 g of pure water were added to the reaction kettle and completely dissolved by stirring. Stirring was stopped, and 95.00 g (0.56 mol) of the compound (M-4) and 5.00 g (0.015 mol) of the compound (M-8) were added. After stirring was started again, 0.50 g (1.3 mmol) of lauroyl peroxide was added and the temperature was raised to 75 DEG C, followed by reaction at 75 DEG C to 80 DEG C for 3 hours. Thereafter, the temperature of the reaction solution was further raised to 95 캜, and this state was maintained for 1 hour to terminate the reaction. After completion of the reaction, the reaction vessel was cooled to 50 캜, and 0.3 g of sodium carbonate was added thereto, followed by stirring for 0.5 hours. Thereafter, the resultant aqueous suspension was filtered through a mesh of 45 탆 nylon filter cloth, washed, and the obtained filtrate was dried at 40 캜 for 16 hours to obtain a granular resin. 50 g of the obtained granular resin and 100 g of? -Butyrolactone were charged into a vessel and stirred at 60 占 폚 for 3 hours. Next, 150 g of propylene glycol monomethyl ether acetate was added to the same container, and the operation of removing solvent by stirring at 80 DEG C for 2 hours was repeated five times. Then, 100 g of tetrahydrofuran was added and the mixture was stirred at 60 DEG C for 1 hour to remove the solvent. This operation was repeated twice, followed by drying under reduced pressure for 24 hours to obtain a polymer (b-1).

[Synthesis Example 8] [Synthesis of polymer (CB-1)] [

50.92 g (80 mol%) of the above compound (M-1) was dissolved in 490 g of propylene glycol monomethyl ether, and 4.70 g of AIBN as a radical polymerization initiator (5 mol% based on the total amount of the compounds) was further prepared to prepare a monomer solution Respectively. Next, a 1 L three-necked flask charged with 12.73 g (20 mol%) of the compound (M-1) and 210 g of propylene glycol monomethyl ether was purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction kettle was heated to 80 DEG C with stirring, and the monomer solution prepared was added dropwise over 3 hours using a dropping funnel. The start of dropwise addition was defined as the polymerization initiation time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization reaction solution was concentrated until the weight of the polymerization reaction solution became 210 g, and then the concentrate was slowly added to 1,050 g of n-hexane to precipitate a solid component. The mixture was decanted to remove the liquid, and the solid was washed three times with 210 g of n-hexane. The obtained solid was dried under reduced pressure at 60 ° C for 15 hours to obtain a polymer (CB-1) (yield: 54.1 g , Yield: 85%). The polymer (CB-1) thus obtained had Mw of 1,200 and Mw / Mn of 2.4. As a result of ¹³ C-NMR analysis, the content ratio of the structural unit derived from (M-1) was 100 mol%.

[Synthesis of [G] polymer]

[Synthesis Example 9] [Synthesis of polymer (G-1)] [

79.9 g (70 mol%) of the compound (M-9) and 20.91 g (30 mol%) of the compound (M-10) were dissolved in 100 g of 2-butanone and dimethyl 2,2'-azo 4.77 g of bisisobutyrate was further dissolved to prepare a monomer solution. Subsequently, a 1,000-mL three-necked flask containing 100 g of 2-butanone was purged with nitrogen for 30 minutes and then heated to 80 DEG C with stirring, and the monomer solution prepared was dropwise added over 3 hours in a dropping funnel. The initiation of the dropwise addition was regarded as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization reaction solution was water-cooled and cooled to 30 캜 or lower. This polymerization reaction liquid was transferred to a 2 L separatory funnel, and then the polymerization reaction liquid was homogeneously diluted with 150 g of n-hexane and 600 g of methanol was added thereto. Subsequently, 30 g of distilled water was added, stirred further, and allowed to stand for 30 minutes. Thereafter, the lower layer was recovered to give a propylene glycol monomethyl ether acetate solution (yield: 60%). The polymer (G-1) thus obtained had Mw of 7,200 and Mw / Mn of 2.00. As a result of ¹³ C-NMR analysis, the content ratio of the structural units derived from (M-9) and (M-10) was 71.1 mol% and 28.9 mol%, respectively.

&Lt; Preparation of resist polymer &

[Example 7] [Production of polymer (A'-1)] [

2,000 g of a 10 mass% methyl isobutyl ketone solution of the (A-1) polymer as the polymer and 2,000 g of the 1 mass% aqueous solution of the (B-1) polymer as the [B] polymer were charged into a separating funnel Respectively. Next, after recovering the organic layer, 2,000 g of a 1% by mass aqueous solution of the polymer (B-1) was added, and the liquid separation operation was performed again. Subsequently, the organic layer was recovered and washed with 2,000 g of distilled water four times. Thereafter, the organic layer was recovered and the solvent was distilled off to obtain a polymer (A'-1). The obtained polymer (A'-1) had an Mw of 6,400 and an Mw / Mn of 1.5. As a result of ¹³ C-NMR analysis, the content ratios of the respective structural units derived from (M-2) and (M-9) were 41.9 mol% and 58.1 mol%, respectively.

[Examples 8 to 12 and Comparative Examples 4 to 9]

(Preparation of Polymers (A'-2) to (A'-6) and (CA'-4) to (CA'-9)

The components [A '] were prepared in the same manner as in Example 7 except that the components shown in Table 3 and the amounts used were used.

[Comparative Example 1] [Production of polymer (CA'-1)] [

100 g of the polymer (b-1) was charged into a column using propylene glycol monomethyl ether acetate, and 2,000 g of a 10 mass% propylene glycol monomethyl ether acetate solution of the polymer (A-1) was passed. The solvent was distilled off from the obtained eluate to prepare a polymer (CA'-1).

[Comparative Examples 2 and 3] [Production of polymers (CA'-2) and (CA'-3)] [

Each component [A '] was prepared in the same manner as in Comparative Example 1 except that the component [B] shown in Table 3 was used.

&Lt; Preparation of resist composition >

Each component other than the [G] polymer constituting the resist composition is shown below.

[[A '] component]

In the Production Examples, the polymers (A'-1) to (A'-6) prepared above were used.

In the comparative production examples, the polymers (CA'-1) to (CA'-9) prepared above and the polymers (A-1) to (A-6) synthesized above were used.

[[E] acid generator]

E-1: Synthesis of a compound represented by the following formula (E-1): triphenylsulfonium 4- (adamantan-1-ylcarbonyloxy) -1,1,2-trifluorobutane- ]

[[F] acid diffusion control agent]

F-1: N- (t-amyloxycarbonyl) -4-hydroxypiperidine [compound represented by the following formula (F-1)

[[H] Solvent]

H-1: Propylene glycol monomethyl ether acetate

H-2: Cyclohexanone

H-3:? -Butyrolactone

[Preparation of Resist Composition]

[Production Example 1]

100 parts by mass of (A'-1) as the polymer [A '], 8.5 parts by mass of (E-1) as the acid generator, 2.3 parts by mass of (F-1) , 3 parts by mass of (G-1) as the [G] polymer and 2,240 parts by mass of (H-1) as the [H] solvent, 960 parts by mass of (H-2) and 30 parts by mass of (H- The obtained mixed solution was filtered with a membrane filter having an opening diameter of 0.2 탆 to prepare a resist composition (J-1).

[Production Examples 2 to 6 and Comparative Production Examples 1 to 15]

(J-1) to (J-6) and (CJ-1) to (CJ-15) were obtained in the same manner as in Preparation Example 1, except that the components shown in Table 4 were used. .

&Lt; Formation of resist pattern &

The obtained resist composition was coated on a 12-inch silicon wafer on which a lower antireflection film was formed by a lower antireflection film-forming composition ("ARC66" manufactured by Nissan Chemical Industries, Ltd.), and the film was subjected to PB for 60 seconds at 100 ° C, Of a resist film was formed. Next, using the ArF excimer laser immersion exposure apparatus ("NSR-S610C" manufactured by Nikon), the resist film was subjected to the conditions of NA = 1.3, ratio = 0.750 and Crosspole, (1L / 1S) mask pattern having a thickness of 10 nm. After the exposure, PEB was performed at 100 캜 for 60 seconds. Next, using a GP nozzle of a developing device ("Clean Track ACT12" manufactured by Tokyo Electron Co., Ltd.), development was carried out for 30 seconds with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide, rinsed with pure water for 7 seconds, followed by liquid phase centrifugal separation at a rpm to form a positive resist pattern. At this time, the exposure amount for forming 1L / 1S of 45 nm width was defined as the optimum exposure amount. 1L / 1S having a line width of 45 nm was formed on the entire surface of the wafer at this optimum exposure amount, thereby forming a wafer for bridge defect inspection. A scanning electron microscope ("CC-4000" manufactured by Hitachi High-Technologies Corporation) was used for the measurement.

<Bridge Defect>

Defects on the wafer for bridge defect inspection were observed using a bright field inspection apparatus (&quot; KLA2810 &quot;, manufactured by KLA-Tencor Corporation). In addition, the defects observed by the bright field inspection apparatus were classified as other than bridge defects and bridge defects. After the classification, the number of bridge defects per wafer was calculated to be the number of bridge defects. The evaluation results are shown in Table 4.

From the results in Table 4, it can be said that the number of bridge defects is reduced as compared with the case where the polymer obtained by the production method of the resist polymer of the example is used, compared with the case of using the polymer obtained by the comparative example.

According to the method for producing a resist polymer of the present invention, a resist polymer excellent in the bridge defect suppressing property of a resist composition can be easily produced with high reproducibility. The polymer used in the process for producing a resist polymer of the present invention can be suitably used as a polymer used in the process for producing the resist polymer. Accordingly, it is possible to produce a resist polymer which can be appropriately used for a semiconductor device manufacturing process and the like, which are expected to progressively become finer thereafter.

Claims (11)

A first polymer having a structural unit comprising a first structure, a second polymer having a structural unit comprising a second structure and another structural unit and being different from the first polymer, a first solvent, And a step of bringing a second solvent which is not dissolved together into contact with each other,
Wherein the first structure and the second structure are of the same type. The method of claim 1, wherein in the contacting step, a first composition containing the first polymer and the first solvent is contacted with a second composition containing the second polymer and the second solvent. Lt; / RTI &gt; The method for producing a resist polymer according to claim 1 or 2, wherein the first structure and the second structure have a polarity. The method for producing a resist polymer according to claim 3, wherein the polar structure is a lactone structure, a cyclic carbonate structure, a sultone structure, an alcohol structure, a carboxylic acid structure, or an amine structure. The method for producing a resist polymer according to any one of claims 1 to 4, wherein the other structural unit comprises a third structure having a higher polarity than the second structure in the second polymer. The method of producing a resist polymer according to claim 5, wherein the third structure is a lactam structure. The method for producing a resist polymer according to any one of claims 1 to 6, wherein the first structure of the first polymer and the second structure of the second polymer are the same. 8. The method according to any one of claims 1 to 7, wherein the first solvent comprises an organic solvent and the second solvent comprises water. 9. The method for producing a resist polymer according to any one of claims 1 to 8, wherein the first polymer has a structural unit containing an acid-dissociable group. A polymer for use in the method for producing a resist polymer according to any one of claims 1 to 9,
A polymer having a structural unit comprising one structure and another structural unit. 11. The polymer according to claim 10, wherein the other structural unit comprises a structure having a higher polarity than the structure.