KR20150048066A - Radiation-sensitive resin composition, method for forming resist pattern, polymer, compound and method for manufacturing the same - Google Patents

Abstract

The present invention provides a radiation-sensitive resin composition with improved LWR performance, CD uniformity, resolution, rectangularity, the depth of focus, exposure margin, and MEEF performance. Particularly, provided are a polymer having a structure unit (I) represented by chemical formula (1), and a radiation-sensitive resin composition containing a radiation-sensitive acid generator. In the chemical formula (1), R^2 is hydrogen atoms or a monovalent organic group, R^3 is a monovalent organic group including polar group, and R^2 and R^3 are combined together so as to represent an alicyclic structure having 3 to 20 reduced water including a polar group formed with carbon atoms to which R^2 and R^3 are bonded. In addition, X and Y are independently a single bond, a divalent chain hydrocarbon group of carbon atoms 1 to 12, or a divalent alicyclic hydrocarbon group of carbon atoms 3 to 12, and R^2 or X and R^1 are combined with each other to represent a ring structure having 5 to 20 reduced water formed with an atomic chain to which R^2 or X and R^1 are bonded.

Description

TECHNICAL FIELD [0001] The present invention relates to a radiation-sensitive resin composition, a resist pattern forming method, a polymer, a compound and a method for producing the same,

The present invention relates to a radiation-sensitive resin composition, a resist pattern forming method, a polymer, a compound and a process for producing the same.

BACKGROUND ART [0002] As various electronic device structures such as semiconductor devices and liquid crystal devices are miniaturized, resist patterns in a lithography process are required to be further miniaturized, and thus various radiation-sensitive resin compositions have been studied. Such a radiation-sensitive resin composition can be produced by forming an acid in an exposed portion by irradiation with radiation such as deep ultraviolet rays such as ArF excimer laser light or electron beam, and dissolving the exposed portion of the exposed and unexposed portion in a developing solution And a resist pattern is formed on the substrate.

Such a radiation sensitive resin composition not only has excellent resolution and merits but also excellent LWR (Line Width Roughness) performance, CDU (Critical Dimension Uniformity) performance and the like, and also has excellent exposure latitude, It is required to obtain a pattern with a high depth of focus and a high precision with a high yield. With respect to this requirement, the structure of the polymer contained in the radiation-sensitive resin composition is variously examined, and by having a lactone structure such as a butyrolactone structure or a norbornane lactone structure, adhesion of the resist pattern to the substrate is enhanced (See Japanese Unexamined Patent Application Publication Nos. 11-212265, 2003-5375, and 2008-83370). It is known that the performance of these devices can be improved.

However, at present, when the fineness of the resist pattern has progressed to a level of 45 nm or less in line width, the required level of performance is further increased, and the conventional radiation-sensitive resin composition can not satisfy these requirements. In addition, in the conventional radiation-sensitive resin composition, top loss of the pattern sometimes occurs, and there is a problem that it is difficult to obtain a pattern having excellent rectangularity in sectional shape. In addition, a resist pattern having high performance such as MEEF (Mask Error Enhancement Factor) performance is recently required.

Japanese Patent Application Laid-Open No. 11-212265 Japanese Patent Application Laid-Open No. 2003-5375 Japanese Patent Application Laid-Open No. 2008-83370

SUMMARY OF THE INVENTION The present invention has been made based on the above-described circumstances, and its object is to provide a method of manufacturing a semiconductor device, which has LWR performance, CD uniformity, resolution, rectangularity of sectional shape, depth of focus, exposure margin and MEEF performance ), Which is excellent in radiation resistance.

The present invention for solving the above problems is characterized in that a polymer having a structural unit (I) represented by the following general formula (1) (hereinafter also referred to as a "[A] polymer") and a radiation- (B) a radiation-sensitive acid generator ").

(1), R ¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R ² is a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic group containing a polar group, R ² and R ³ may combine with each other to form an alicyclic structure having 3 to 20 ring members including a polar group, which is constituted together with carbon atoms to which they are bonded, R ⁴ is a monovalent organic group, and X and Y is independently a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, provided that at least one of X and Y is a divalent straight chain A hydrocarbon group or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, and R ² or X and R ¹ may be combined with each other to form a ring structure having a reduced number of 5 to 20,

In another aspect of the present invention, there is provided a resist pattern forming method comprising forming a resist film, exposing the resist film, and developing the exposed resist film, A resist pattern forming method comprising:

Another invention made to solve the above problems is a polymer having a structural unit (I) represented by the following general formula (1).

(1), R ¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R ² is a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic group containing a polar group, R ² and R ³ may combine with each other to form an alicyclic structure having a reducing number of 3 to 20, which is constituted together with the carbon atoms to which they are bonded, and R ⁴ is a monovalent organic group; X and Y are each independently , A bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, provided that at least one of X and Y is a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a divalent straight chain hydrocarbon group having 3 to 12 carbon atoms And R < ² > or X and R < ¹ > are taken together with the atomic group to which they are bonded to form a ring structure having a reduced number of 5 to 20)

A separate invention for solving the above problems is a compound represented by the following chemical formula (5).

(5), R ¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R ² is a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic group containing a polar group, R ² and R ³ may combine with each other to form an alicyclic structure having a reducing number of 3 to 20, which is constituted together with the carbon atoms to which they are bonded, and R ⁴ is a monovalent organic group; X and Y are each independently , A bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, provided that at least one of X and Y is a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a divalent straight chain hydrocarbon group having 3 to 12 carbon atoms And R < ² > or X and R < ¹ > are taken together with the atomic group to which they are bonded to form a ring structure having a reduced number of 5 to 20)

Another invention made to solve the above problems is a process for producing a compound represented by the following formula (5a) having a step of reacting a compound represented by the following formula (a) with a compound represented by the following formula (b) to be.

(Wherein R ^1A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R ^2A is a hydrogen atom or a monovalent organic group, and R ³ is a polar group. In the formulas (a), (b) , Provided that R ^{2 A} and R ³ may combine with each other to form an alicyclic structure having 3 to 20 reduced groups including a polar group together with the carbon atom to which they are bonded, and R ⁴ is a monovalent organic group , X ^A and Y are each independently a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, provided that at least one of X ^A and Y is a straight- Z is a halogen atom, a hydroxy group, or -OCOR ', and R' is a monovalent hydrocarbon group having 1 to 30 carbon atoms), a divalent acyclic hydrocarbon group having 1 to 12 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms,

Another invention made to solve the above problems is a process for producing a compound represented by the following formula (5b) having a step of reacting a compound represented by the following formula (e) and a compound represented by the following formula (f) ≪ / RTI >

(In the formulas (e), (f) and (5b), R ^2A is a hydrogen atom or a monovalent organic group and R ³ is a monovalent organic group containing a polar group, provided that R ^2A and R ³ are combined with each other, And R ⁴ is a monovalent organic group; Y is a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms; or a divalent straight chain hydrocarbon group having 3 to 20 carbon atoms, or an alicyclic hydrocarbon group having 3 to 20 carbon atoms, And R ^X and R ^Y each independently represent a hydrogen atom or a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms, or may be bonded together with a carbon atom or a carbon chain to which they are bonded to form a bivalent alicyclic hydrocarbon group A is an integer of 1 to 4, and when a is 2 or more, plural R ^x may be the same or different, and plural R ^y may be the same or different from each other And may be different , R ^Z is a group having 1 to 10 monovalent chain hydrocarbon group or a monovalent alicyclic having 3 to 10 hydrocarbon group, T is a halogen atom, A is a monovalent oxyhydrocarbon of a halogen atom, a hydroxyl group, having 1 to 20 carbon atoms Group or -OCOR ^T and R ^T is a monovalent hydrocarbon group of 1 to 20 carbon atoms)

Another invention made to solve the above problems is a process for producing a compound represented by the following formula (5c) having a step of reacting a compound represented by the formula (g) and a compound represented by the formula (f) ≪ / RTI >

(In the formulas (g), (f) and (5c), R ³ is a monovalent organic group containing a polar group, R ⁴ is a monovalent organic group and Y is a single bond, a divalent straight chain A hydrocarbon group or a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms; R ^V and R ^W each independently represent a hydrogen atom, a halogen atom, a hydroxy group or a monovalent organic group having 1 to 10 carbon atoms, A is an integer of 1 to 4, and when a is 2 or more, a plurality of R ^v may be the same or different from each other and, a plurality of R ^W is and may be the same or different, T is a halogen atom, a is a monovalent oxyhydrocarbon of a halogen atom, a hydroxyl group, having 1 to 20 carbon atoms or -OCOR ^T, R ^T is a C1 To 20 monovalent hydrocarbon groups)

Herein, the term "organic group" means a group containing at least one carbon atom. The "hydrocarbon group" includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The " hydrocarbon group " may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The term " polar group " refers to a heteroatom-containing group such as a carboxy group, a hydroxyl group, an amino group or a sulfo group.

According to the radiation-sensitive resin composition and the method of forming a resist pattern of the present invention, it is possible to provide a radiation-sensitive resin composition and a resist pattern forming method which exhibit excellent LWR performance, CD uniformity, and rectangularity of cross-sectional shape while exhibiting excellent exposure margin, depth of focus, MEEF performance, A resist pattern can be formed. The polymer of the present invention can be suitably used as a polymer component of the radiation-sensitive resin composition. The compound of the present invention can be suitably used as a monomer of the polymer. According to the method for producing the compound of the present invention, the above compound can be produced easily and at a good yield. Therefore, they can be suitably used for manufacturing semiconductor devices, which are expected to be further miniaturized in the future.

<Radiation-Resistant Resin Composition>

The radiation-sensitive resin composition contains the [A] polymer and the [B] radiation-sensitive acid generator. The radiation-sensitive resin composition preferably contains, as a suitable component, [C] an acid diffusion control material, [D] a fluorine atom-containing polymer (hereinafter also referred to as a " (Hereinafter also referred to as "[E] polymer"), a [F] solvent and a [G] uniformalization accelerator, and may contain other components within the range not impairing the effects of the present invention It is possible.

The radiation-sensitive resin composition may contain only a base polymer as a polymer component, or may contain a water repellent polymer additive in addition to a base polymer. The term &quot; base polymer &quot; refers to a polymer as a main component of a resist film formed of a radiation-sensitive resin composition, and preferably refers to a polymer that accounts for 50 mass% or more of the total polymer constituting the resist film. The &quot; water-repellent polymer additive &quot; is a polymer having a tendency to be unevenly distributed in the surface layer of the formed resist film by being contained in the radiation-sensitive resin composition. The polymer having higher hydrophobicity than the polymer as the base polymer tends to be unevenly distributed in the surface layer of the resist film, and can function as a water repellent polymer additive. Since the radiation-sensitive resin composition contains a water-repellent polymer additive, dissolution of an acid generator or the like from the resist film can be suppressed, and the surface of the formed resist film exhibits a high dynamic contact angle, The water-dropping property can be exhibited. Thus, in the liquid immersion lithography process, it is not necessary to separately form an upper layer film for shielding the surface of the resist film and the immersion medium, and it is possible to perform a high-speed scanning exposure. When the radiation-sensitive resin composition contains a water-repellent additive, the lower limit of the content of the water-repellent polymer additive is preferably 0.1 part by mass, more preferably 0.3 part by mass, further preferably 0.5 part by mass with respect to 100 parts by mass of the base polymer. The upper limit of the content is preferably 20 parts by mass, more preferably 15 parts by mass, further preferably 10 parts by mass. The lower limit of the content of the base polymer in the radiation-sensitive resin composition is preferably 70% by mass, more preferably 80% by mass, and even more preferably 85% by mass, based on the total solid content in the radiation sensitive resin composition .

In order for the polymer to function well as a water-repellent polymer additive in the radiation-sensitive resin composition, the polymer constituting the water-repellent polymer additive is preferably a polymer having a fluorine atom, and the fluorine atom content thereof is preferably in the range of Is more preferable. If the fluorine atom content of the water repellent polymer additive is larger than the fluorine atom content of the base polymer, the water repellent polymer additive tends to be unevenly distributed in its surface layer in the formed resist film, so that the water repellent polymer The properties attributable to the hydrophobicity of the additive are more effectively exhibited. The lower limit of the fluorine atom content of the polymer constituting the water repellent polymer additive is preferably 1% by mass, more preferably 3% by mass, still more preferably 5% by mass, and particularly preferably 7% by mass. The fluorine atom content (% by mass) can be calculated from the structure of the polymer determined by ¹³ C-NMR measurement.

Examples of the form of the polymer component in the radiation sensitive resin composition include (A) a polymer as the base polymer, (2) the [A] polymer as the base polymer and the [A] polymer as the water repellent polymer additive, 3) polymer [A] as a base polymer and a [D] polymer as a water repellent polymer additive, [4] a polymer [D] as a base polymer and a polymer [A] as a water repellent polymer additive. The radiation-sensitive resin composition in which the base polymer is the [A] polymer as described in the above (1) to (3) exhibits an effect of particularly excellent depth of focus. Further, the radiation-sensitive resin composition containing the polymer [A] as the water-repellent polymer additive as in the above (2) and (4) has an effect of suppressing the occurrence of defects in the resist pattern to be formed. In this case, when both the base polymer and the water-repellent polymer additive are made of the polymer [A] as in the above (2), the defect restraining property can be further improved. Hereinafter, each component of the radiation-sensitive resin composition will be described.

<[A] Polymer>

[A] Polymer is a polymer having a structural unit (I). By using the radiation sensitive resin composition, it is possible to form a resist pattern having high LWR performance, CD uniformity and rectangular cross-sectional shape and high resolution while exhibiting excellent exposure margin, depth of focus and MEEF performance . The reason why the radiation-sensitive resin composition has the above-mentioned structure and exhibits the above effect is not necessarily clear, but can be estimated as follows, for example. That is, the structural unit (I) of the polymer [A] has a polar group in the vicinity of an ester group bonded to the main chain. The structure unit (I) has such a structure that the rigidity and polarity of the [A] polymer are appropriately increased, and the diffusion of the acid generated from the [B] radiation-sensitive acid generator in the resist film can be suitably controlled . Further, the solubility of the [A] polymer is increased, and as a result, the above-described LWR performance and the like are improved.

The polymer [A] is a structural unit other than the structural unit (I), the structural unit (II) and the structural unit (I) represented by the following formula (2) , A sultone structure, a hydroxyl group or an oxo group, and may have other structural units other than the structural units (I) to (III). The polymer [A] may have one or more of the structural units described above. Hereinafter, each structural unit will be described.

[Structural unit (I)]

The structural unit (I) is represented by the following formula (1).

In the above formula (1), R ¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ² is a hydrogen atom or a monovalent organic group. R ³ is a monovalent organic group containing a polar group. Provided that R ² and R ³ may combine with each other to form an alicyclic structure having 3 to 20 reduced groups containing a polar group together with carbon atoms to which they are bonded. R ⁴ is a monovalent organic group. X and Y each independently represent a single bond, a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. Provided that at least one of X and Y is a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. R ² or X and R ¹ may represent a ring structure having a reduced number of 5 to 20, which is taken together with the atomic group to which they are bonded.

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

When R ² is a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic group containing a polar group. In this case, it is presumed that the mobility and solubility of the polymer [A] can be easily controlled.

The monovalent organic group of R ² may contain a polar group, so long as the effect of the present invention is not impaired. That is, as a monovalent organic group of R ² , for example, a monovalent organic group including a polar group may be used.

Examples of the monovalent organic group of R ² include a linear 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, Monovalent hydrocarbon groups, and the like.

As the chain hydrocarbon group having 1 to 20 carbon atoms, for example,

Alkyl groups such as methyl group, ethyl group, propyl group and butyl group;

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

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

As the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, for example,

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

A polycyclic cycloalkyl group such as a norbornyl group, an adamantyl group, and a tricyclodecyl 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.

As the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, for example,

An aryl group such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and an anthryl group;

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

Of these, R &lt; ² &gt; is preferably a hydrogen atom and a monovalent hydrocarbon group of 1 to 20 carbon atoms, more preferably a hydrogen atom and a chain hydrocarbon group of 1 to 20 carbon atoms, from the viewpoint of more easily controlling the motility of the polymer And a methyl group is more preferable.

Examples of the moiety excluding the polar group of R ³ include, for example, groups exemplified as a monovalent organic group of R ² .

As the polar group of R ³ , for example,

A monovalent polar group such as a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, a hydroxyl group, an amino group, a carboxyl group, an alkoxy group, an amide group or a cyano group;

A divalent polar group such as -O-, -O-, -CO-, -CO ₂ -, -O-CO ₂ -, -NH-, -S-, -SO ₂ -, -O-SO ₂ -;

And a trivalent polar group such as -CON <

As the polar group of R ³ , a hydroxyl group, -O-, -CO ₂ -, -O-CO ₂ -, -O-SO ₂ -, and -O- are preferred from the viewpoint of more easily adjusting the solubility of the polymer [A] And -CON <are preferable, and a hydroxy group, -CO ₂ - and -O-SO ₂ - are more preferable.

Examples of the monovalent organic group containing a polar group of R ³ include groups represented by the following formulas (a-1) to (a-44).

In the above formulas (a-1) to (a-44), each * is a bonding hand.

As a monovalent organic group containing a polar group of R ³ , a fluorine atom, a hydroxy group, an amino group, a cyano group, -CO ₂ - and --COO- groups as a polar group from the viewpoint that the solubility of the polymer [A] O-SO ₂ - preferably the first organic group is monovalent, including, respectively, and the formula (a-1), (a -5), (a-12), (a-13), (a-15), (a More preferably a group represented by (a-21), (a-21), (a-31) More preferably a monovalent organic group containing -CO ₂ -, and particularly preferably a group represented by the above formula (a-15).

R ² and R ³ may combine with each other to form an alicyclic structure having 3 to 20 reduced groups comprising a polar group, which is constituted together with the carbon atoms to which they are bonded. In this case as well, it is presumed that the mobility and solubility of the polymer [A] can be easily controlled.

As the alicyclic structure excluding the polar group, for example, an alicyclic hydrocarbon structure of 3 to 20 in reduced number can be given.

As the alicyclic hydrocarbon structure having 3 to 20 carbon atoms, for example,

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

A norbornane structure, and an adamantane structure, and the like.

As the alicyclic hydrocarbon structure having 3 to 20 carbon atoms, from the viewpoint that the solubility of the polymer [A] can be more easily controlled, a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a norbornane structure, Structure is preferable, and a cyclopropane structure, a norbornane structure and an adamantane structure are more preferable.

Examples of the polar group of the alicyclic structure of the reduced number 3 to 20 include the groups exemplified as the polar group of R ³ .

As the polar group of the alicyclic structure of the reduced number 3 to 20, a fluorine atom, a hydroxy group, -O-, -CO-, -CO ₂ -, - SO ₂ -, -O-SO ₂ - and -CON <are preferable, and a hydroxy group, -CO ₂ - and -O-SO ₂ - are more preferable.

Examples of the alicyclic structure of the reducing group 3 to 20 including the polar group include the structures represented by the following formulas (b-1) to (b-14).

In the above formulas (b-1) to (b-14), each * is a bonding hand.

As the alicyclic structure of the reduced group 3 to 20 containing a polar group, a hydroxyl group, -O-, -CO ₂ - and -O-SO ₂ - are included as the polar group, respectively, from the viewpoint of appropriately increasing the solubility of the polymer [A] (B-3), (b-9), (b-10), (b-11) and (b-13) And the group represented by each is more preferable.

Examples of the monovalent organic group represented by R ⁴ include groups exemplified as monovalent organic groups of R ² , and the like.

The monovalent organic group of R ⁴ may contain a polar group as in the case of R ² so long as the effect of the present invention is not impaired. That is, examples of monovalent organic groups represented by R ⁴ include monovalent organic groups including a polar group.

Examples of the monovalent organic group represented by R ⁴ include groups represented by the following formulas (c-1) to (c-14).

In the above formulas (c-1) to (c-14), each * is a bonding hand.

Examples of the polar group which may be contained in R ⁴ include, for example, groups exemplified as the polar group of R ³ .

As the polar group which may be contained in R ⁴ , a fluorine atom, a hydroxy group, -CO ₂ - and -O-SO ₂ - are preferable from the viewpoint that the solubility of the polymer [A] can be more easily controlled.

Examples of the monovalent organic group containing the polar group of R ⁴ include groups represented by the above formulas (a-1) to (a-44).

R ⁴ may be an acid dissociable group or a non-acid dissociable group. When R ⁴ is an acid dissociable group, the acid dissociability and polarity can be exerted together with the structural unit (I), and the solubility of the polymer [A] can be controlled more appropriately. As a result, LWR performance and the like can be further increased.

As the monovalent organic group of R ^4, those from [A] a polymer with [B] the acid dissociation in view increasing the compatibility-sensitive acid generating material, R ⁴ is monovalent acid-dissociable group, and the polar group as a fluorine atom, a hydroxy group, -CO ₂ - and -O-SO ₂ - a divalent organic group containing 1 each preferably and, a monovalent acid-dissociable group, and the more preferred, the formula (c-2), (c -3), (c-4 ), (c-5), (c-8), (c-9) and (c-12).

As the bivalent straight chain hydrocarbon group of 1 to 12 carbon atoms for X and Y, for example,

Alkanediyl groups such as methanediyl, ethanediyl, propanediyl and butanediyl;

Alkenediyl groups such as an etendiyl group, a propenediyl group, and a butenediyl group;

An alkynediyl group such as an ethynyl group, an ethynyl group, an ethynyl group, an ethynyl group, an ethynyl group, an ethynyl group, an ethynyl group, an ethynyl group, an ethynyl group,

Examples of the bivalent alicyclic hydrocarbon group of 3 to 12 carbon atoms represented by X and Y include,

Monocyclic cycloalkanediyl groups such as cyclopropanediyl, cyclobutanediyl, cyclobutanediyl, cyclopentanediyl, cycloheptanediyl and cyclohexanediyl;

Monocyclic cycloalkenediyl groups such as cyclopropenediyl group and cyclobutenediyl group;

A polycyclic cycloalkanediyl group such as a norbornanediyl group, an adamantanediyl group, a tricyclodecanediyl group, and a tetracyclododecanediyl group;

Norbornenediyl group, and tricyclodecenediyl group, and the like can be given.

The bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms and the bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms may have a substituent such as a cyclopentyl group, a cyclohexyl group, an adamantyl group and a norbornyl group, A monovalent alicyclic hydrocarbon group may be substituted as a substituent.

More specifically, examples of the divalent straight chain hydrocarbon group having 1 to 12 carbon atoms and the divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms represented by X and Y include groups represented by the following formulas (d-1) to (d-12) And the like.

In the above formulas (d-1) to (d-12), each * is a bonding hand.

X and Y are preferably a divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms, more preferably 1 and 2 carbon atoms. In this case, the mobility of the polymer [A] can be more easily controlled. Provided that at least one of X and Y represents a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms.

As X and Y, a single bond, an alkanediyl group and a cycloalkanediyl group are preferable from the viewpoint of more easily controlling the motility of the polymer [A], and a single bond, the above-mentioned formulas (d-1) and (D-3), (d-5) and (d-11) are more preferable and the groups represented by the formulas (d-1) and Is more preferable.

Examples of the ring structure of the reduced number 5 to 20, in which R ² and R ¹ are combined with each other to form an atomic chain to which they are bonded,

A lactone structure such as a butyrolactone structure, a valerolactone structure, and a caprolactone structure;

And oxalactone structures such as oxabutyl lactone structure and oxabalorolactone.

Among them, a lactone structure is preferable, a lactone structure having a reduced number of 5 to 8 is more preferable, a butyrolactone structure and a valerolactone structure are more preferable, and a butyrolactone structure is particularly preferable.

Examples of the ring structure of a reduced number of 5 to 20, in which X and R ¹ are combined with each other to form an atomic chain to which they are bonded, include lactone structures such as a butyrolactone structure, a valerolactone structure, and a caprolactone structure. .

Of these, a lactone structure having a reduced number of 5 to 8 is preferable, a butyrolactone structure and a valerolactone structure are more preferable, and a butyrolactone structure is more preferable.

Examples of the structural unit (I) include a structural unit represented by the following formula (1a) (hereinafter also referred to as "structural unit (Ia)"), a structural unit represented by the following formula (1b) (Hereinafter also referred to as &quot; structural unit (Ic) &quot;) and a structural unit represented by the following formula (1c)

In the above formula (1a), R ^1A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^2A is a hydrogen atom or a monovalent organic group. R ³ is a monovalent organic group containing a polar group. Provided that R &lt; ^2A &gt; and R &lt; ³ &gt; may combine with each other to form an alicyclic structure having 3 to 20 reduced groups containing a polar group, R ⁴ is a monovalent organic group. X ^A and Y are each independently a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. Provided that at least one of X ^A and Y is a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms.

In the above formula (1b), R ^2A is a hydrogen atom or a monovalent organic group. R ³ is a monovalent organic group containing a polar group. Provided that R &lt; ^2A &gt; and R &lt; ³ &gt; may combine with each other to form an alicyclic structure having 3 to 20 reduced groups containing a polar group, R ⁴ is a monovalent organic group. Y is a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. R ^X and R ^Y are each independently a hydrogen atom or a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms in which these groups are combined with each other to form a carbon atom or a carbon chain to which they are bonded, . a is an integer of 1 to 4; When a is 2 or more, plural R ^x may be the same or different, and plural R ^y may be the same or different. R ^Z is a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms.

In the above formula (1c), R ³ is a monovalent organic group containing a polar group. R ⁴ is a monovalent organic group. Y is a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. R ^V and R ^W are each independently a hydrogen atom, a halogen atom, a hydroxy group or a monovalent organic group having 1 to 10 carbon atoms, or a combination of these groups combined with a carbon atom or a carbon chain to which they are bonded, 10 &lt; / RTI &gt; ring structure. a is an integer of 1 to 4; When a is 2 or more, plural R ^V may be the same or different, and plural R ^W may be the same or different.

The structural unit (Ib) is a structure in which X and R ¹ of the structural unit (I) are combined with each other to form a lactone structure having a reduced number of 5 to 8 together with -COO- to which they are bonded. In the structural unit (Ic), X in the structural unit (I) is a single bond, and R ² and R ¹ are combined with each other to form a lactone structure having a reduced number of 5 to 8 together with -COO- bonded thereto.

Examples of the structural unit (I) include structural units represented by the following formulas (I-1) to (I-186).

(I-1) to (I-7), (I-9), and (I-11) (I-13) to (I-18), (I-20), (I-22) (I-36), (I-37), I-39, I-41, I-42, I-44 to I- (I-1) is preferably a structural unit represented by the formula (I-5), (I-58), (I-61) And (I-37) are particularly preferable.

When the polymer [A] is a base polymer, the lower limit of the content of the structural unit (I) is preferably 1 mol%, more preferably 5 mol%, and preferably 10 mol%, based on the total structural units constituting the polymer [A] %, And particularly preferably 15 mol%. The upper limit of the content of the structural unit (I) is preferably 100 mol%, more preferably 70 mol%, still more preferably 50 mol%, still more preferably 35 mol% and still more preferably 25 mol% . By setting the content ratio within the above range, the above-described LWR performance and the like are improved. When the content ratio is less than the above lower limit, the above effects may not be sufficiently exhibited. When the content ratio exceeds the upper limit, the pattern-forming property of the radiation-sensitive resin composition may be deteriorated.

When the polymer [A] is a water-repellent polymer additive, the lower limit of the content of the structural unit (I) is preferably 1 mol%, more preferably 5 mol%, with respect to the total structural units constituting the polymer [A] , And still more preferably 20 mol%. The upper limit of the content is preferably 95 mol%, more preferably 60 mol%, still more preferably 40 mol%.

<Compound>

As the compound giving the structural unit (I), for example, a compound represented by the following formula (5) can be given.

In the formula (5), R ¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ² is a hydrogen atom or a monovalent organic group. R ³ is a monovalent organic group containing a polar group. Provided that R &lt; ² &gt; and R &lt; ³ &gt; are taken together with the carbon atom to which they are attached to form an alicyclic structure of 3 to 20 in number including a polar group. R ⁴ is a monovalent organic group. X and Y each independently represent a single bond, a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. Provided that at least one of X and Y is a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. R ² or X and R ¹ may represent a ring structure having a reduced number of 5 to 20, which is taken together with the atomic group to which they are bonded.

As the compound represented by the formula (5), a compound represented by the following formula (5a), a compound represented by the following formula (5b) and a compound represented by the following formula (5c) are preferable.

In the above formula (5a), R ^1A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^2A is a hydrogen atom or a monovalent organic group. R ³ is a monovalent organic group containing a polar group. Provided that R &lt; ^2A &gt; and R &lt; ³ &gt; may combine with each other to form an alicyclic structure having 3 to 20 reduced groups containing a polar group, R ⁴ is a monovalent organic radical. X ^A and Y are each independently a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. Provided that at least one of X ^A and Y is a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms.

In the above formula (5b), R ^2A is a hydrogen atom or a monovalent organic group. R ³ is a monovalent organic group containing a polar group. Provided that R &lt; ^2A &gt; and R &lt; ³ &gt; may combine with each other to form an alicyclic structure having 3 to 20 reduced groups containing a polar group, R ⁴ is a monovalent organic group. Y is a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. R ^X and R ^Y are each independently a hydrogen atom or a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms in which these groups are combined with each other to form a carbon atom or a carbon chain to which they are bonded, . a is an integer of 1 to 4; When a is 2 or more, plural R ^x may be the same or different, and plural R ^y may be the same or different. R ^Z is a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms.

In the above formula (5c), R ³ is a monovalent organic group containing a polar group. R ⁴ is a monovalent organic group. Y is a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. R ^V and R ^W are each independently a hydrogen atom, a halogen atom, a hydroxy group or a monovalent organic group having 1 to 10 carbon atoms, or a combination of these groups combined with a carbon atom or a carbon chain to which they are bonded, 10 &lt; / RTI &gt; ring structure. a is an integer of 1 to 4; When a is 2 or more, plural R ^V may be the same or different, and plural R ^W may be the same or different.

More specifically, examples of the compound represented by the formula (5) include compounds represented by the following formulas (e-1) to (e-186).

(E-1) to (e-7), (e-9), and (e-5) (e-11), (e-13) to (e-18), (e-20) (E-44) to (e-47), (e-51), ), e-53, e-58, e-61, e-99 and e-131 to e- -1) and (e-37) are particularly preferable.

&Lt; Preparation method of compound &

The compound represented by the above formula (5a)

Can be produced in a simple and good yield by a production method having a step of reacting a compound represented by the formula (a) and a compound represented by the formula (b) shown below.

In the above formulas (a), (b) and (5a), R ^1A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^2A is a hydrogen atom or a monovalent organic group. R ³ is a monovalent organic group containing a polar group. Provided that R &lt; ^2A &gt; and R &lt; ³ &gt; may combine with each other to form an alicyclic structure having 3 to 20 reduced groups containing a polar group, R ⁴ is a monovalent organic group. X ^A and Y are each independently a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. Provided that at least one of X ^A and Y is a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. Z is a halogen atom, a hydroxy group or -OCOR '. R 'is a monovalent hydrocarbon group having 1 to 30 carbon atoms.

For example, a compound represented by the formula (5a) is produced by reacting a compound represented by the formula (a) and a compound represented by the formula (b) in a solvent such as acetonitrile in the presence of a base such as triethylamine or the like do. The reaction solution is concentrated and then subjected to separation treatment, distillation, recrystallization, column chromatography or the like to isolate the compound represented by formula (5a).

When X is a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, the compound represented by the formula (a)

A step of reacting a compound represented by the formula (c) and a compound represented by the formula (d) in the presence of zinc

By weight.

In the above formulas (a), (c) and (d), R ^2A is a hydrogen atom or a monovalent organic group. R ³ is a monovalent organic group containing a polar group. Provided that R &lt; ^2A &gt; and R &lt; ³ &gt; may combine with each other to form an alicyclic structure having 3 to 20 reduced groups containing a polar group, R ⁴ is a monovalent organic group. X ^A is a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. Y is a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. Z 'is a halogen atom.

For example, when X ^A is a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, the carbonyl compound represented by the formula (c) and the compound represented by the formula (d) Is reacted with a halogen compound in the presence of metal zinc in a solvent such as tetrahydrofuran to obtain a compound represented by the above formula (a).

Examples of the halogen atom represented by Z 'include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Among them, chlorine atom and bromine atom are preferable and bromine atom is more preferable from the viewpoint of yield improvement.

The compound represented by the above formula (5b)

A step of reacting a compound represented by the following formula (e) with a compound represented by the following formula (f) in the presence of metal zinc

Can be produced easily and at a good yield by the production method having

In the above formulas (e), (f) and (5b), R ^2A is a hydrogen atom or a monovalent organic group. R ³ is a monovalent organic group containing a polar group. Provided that R &lt; ^2A &gt; and R &lt; ³ &gt; may combine with each other to form an alicyclic structure having 3 to 20 reduced groups containing a polar group, R ⁴ is a monovalent organic group. Y is a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. R ^X and R ^Y are each independently a hydrogen atom or a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms in which these groups are combined with each other to form a carbon atom or a carbon chain to which they are bonded, . a is an integer of 1 to 4; When a is 2 or more, plural R ^x may be the same or different, and plural R ^y may be the same or different. R ^Z is a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. T is a halogen atom. A is a halogen atom, a hydroxy group, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, or -OCOR ^T. R ^T is a monovalent hydrocarbon group of 1 to 20 carbon atoms.

The compound represented by the above formula (5c)

A step of reacting a compound represented by the following formula (g) with a compound represented by the following formula (f) in the presence of metal zinc

Can be produced easily and at a good yield by the production method having

In the above formulas (g), (f) and (5c), R ³ is a monovalent organic group containing a polar group. R ⁴ is a monovalent organic group. Y is a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. R ^V and R ^W are each independently a hydrogen atom, a halogen atom, a hydroxy group or a monovalent organic group having 1 to 10 carbon atoms, or a combination of these groups combined with a carbon atom or a carbon chain to which they are bonded, 10 &lt; / RTI &gt; ring structure. a is an integer of 1 to 4; When a is 2 or more, plural R ^V may be the same or different, and plural R ^W may be the same or different. T is a halogen atom. A is a halogen atom, a hydroxy group, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, or -OCOR ^T. R ^T is a monovalent hydrocarbon group of 1 to 20 carbon atoms.

The halogen atom of T in the above formula (f) is preferably a chlorine atom and a bromine atom, and more preferably a bromine atom.

In formula (f), A is preferably an oxyhydrocarbon group, more preferably an alkoxy group, and more preferably an ethoxy group.

For example, the compound represented by the formula (e) or the compound represented by the formula (g) and the compound represented by the formula (f) are reacted in the presence of an activating agent such as metal zinc and trimethylsilyl chloride in tetrahydrofuran (5b) or (5c) is produced. (5b) or (5c) can be isolated by concentrating the reaction solution and then appropriately treating it by liquid separation, distillation, recrystallization, column chromatography or the like.

[Structural unit (II)]

The structural unit (II) is a structural unit represented by the following formula (2) or (3). When the polymer [A] further comprises the structural unit (II) represented by the following formula (2) or (3), the sensitivity and resolution of the radiation sensitive resin composition are improved and as a result, the above- .

In the above formula (2), R ⁵ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ⁶ is a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. R ⁷ and R ⁸ are each independently a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms in which these groups are combined with each other to form a carbon- To 20 &lt; / RTI &gt;

In the above formula (3), R ⁹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. p is 0 or 1; However, a part or all of the hydrogen atoms of the cycloalkenyl group may be substituted with a hydrocarbon group. The carbon atom of the cycloalkenyl group may be crosslinked with a hydrocarbon chain.

The group represented by -CR ⁶ R ⁷ R ⁸ in the above formula (2) and the cycloalkenyl group in the formula (3) are acid dissociable groups.

As R ⁵ , a hydrogen atom and a methyl group are preferable from the viewpoint of copolymerization of a monomer giving the structural unit (II), and a methyl group is more preferable.

As the monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms represented by R ⁶ , R ⁷ and R ⁸ , for example,

Alkyl groups such as methyl group, ethyl group, n-propyl group and i-propyl group;

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

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

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ⁶ , R ⁷ and R ⁸ include, for example,

Monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group;

Monocyclic cycloalkenyl group such as cyclopentenyl group and cyclohexenyl group;

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

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

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 include, for example,

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

A cycloalkane structure such as a norbornane structure, an adamantane structure, a tricyclodecane structure, and a tetracyclododecane structure; and the like.

As the structural unit (II) represented by the general formula (2), structural units represented by the following general formulas (II-1) to (II-4) are preferable.

In the formulas (II-1) to (II-4), R ⁵ to R ⁸ are as defined in the formula (2). i and j are each independently an integer of 1 to 4;

More specifically, examples of the structural units (II-1) to (II-4) include structural units represented by the following formulas (II-5) to (II-26).

In the above formulas (II-5) to (II-26), R ⁵ is synonymous with the above formula (2).

On the other hand, as R ⁵ in the formula (3), a hydrogen atom and a methyl group are preferable from the viewpoint of copolymerization of a monomer giving the structural unit (II), and a methyl group is more preferable.

Examples of the hydrocarbon group which may substitute some or all of the hydrogen atoms of the cycloalkenyl group include monovalent hydrocarbon groups of 1 to 20 carbon atoms exemplified as monovalent organic groups of R ² , Is preferably a chain hydrocarbon group having 1 to 20 carbon atoms and more preferably a methyl group from the viewpoint of further improving the sensitivity and resolution of the radiation sensitive resin composition.

Examples of the hydrocarbon chain which may be bridged between the carbon atoms of the cycloalkenyl group include a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms and a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, A bivalent chain hydrocarbon group having 1 to 12 carbon atoms, and a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. Of these, from the viewpoint of further improving the sensitivity and resolution of the radiation sensitive resin composition, A bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms is preferable, and a methylene group is more preferable.

Examples of the structural unit (II) represented by the formula (3) include structural units represented by the following formulas (II-27) to (II-38).

In the formulas (II-27) to (II-38), R ⁹ is the same as in the above formula (3).

As the structural unit (II), the structural unit (II-1), the structural unit (II-2), the structural unit (II-3) The structural unit represented by the above formula (3) is preferable, the above-mentioned structural unit represented by the above formula (II-1) is more preferable, and the structural unit represented by the above formula (II-5) is more preferable.

When the polymer [A] is a base polymer, when the polymer [A] has the structural unit (II), the lower limit of the content of the structural unit (II) Mol, more preferably 20 mol%, still more preferably 25 mol%, and particularly preferably 30 mol%. The upper limit of the content is preferably 80 mol%, more preferably 70 mol%, still more preferably 60 mol%. By setting the content ratio within the above range, the sensitivity of the radiation sensitive resin composition is further improved, and as a result, the above-described LWR performance and the like are improved. If the content is less than the lower limit, the pattern forming property of the radiation-sensitive resin composition may be deteriorated. If the content ratio exceeds the upper limit, the adhesion of the resist pattern to the substrate may be lowered. When the polymer [A] has the structural unit (II) in the case where the polymer [A] is a water repellent polymer additive, the lower limit of the content ratio of the structural unit (II) Is preferably 10 mol%, more preferably 30 mol%, still more preferably 45 mol%, and particularly preferably 60 mol%. The upper limit of the content is preferably 90 mol%, more preferably 80 mol%, still more preferably 75 mol%.

[Structural unit (III)]

The structural unit (III) is a structural unit other than the structural unit (I), and is a structural unit containing a lactone structure, a cyclic carbonate structure, a sultone structure, a hydroxyl group or an oxo group. By further having the structural unit (III) in the polymer [A], the solubility in a developer can be further adjusted, and as a result, the above-described LWR performance and the like are improved. Further, adhesion between the resist pattern formed of the radiation sensitive resin composition and the substrate can be improved.

Examples of the structural unit (III) include structural units represented by the following formulas (III-1) to (III-47).

In the formulas (III-1) to (III-47), R ^L1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

As the structural unit (III), a structural unit containing a lactone structure is preferable from the viewpoint of further adjusting the solubility of the polymer [A] in a developing solution, and the structural unit represented by the formula (III-1) desirable.

When the polymer (A) has the structural unit (III), the lower limit of the content of the structural unit (III) is preferably 10 mol% based on the total structural units constituting the polymer [A] , More preferably 35 mol%. The upper limit of the content is preferably 70 mol%, more preferably 65 mol%, still more preferably 55 mol%. By setting the content ratio within the above range, the adhesion of the resist pattern formed of the radiation-sensitive resin composition to the substrate can be further improved. If the content is less than the lower limit, the adhesion of the resist pattern formed of the radiation sensitive resin composition to the substrate may be lowered. When the content ratio exceeds the upper limit, the pattern-forming property of the radiation-sensitive resin composition may be deteriorated.

[Other structural units]

The polymer [A] may have other structural units other than the structural units (I) to (III), so long as the effect of the present invention is not impaired.

As the other structural unit, for example, a structural unit containing a non-reactive hydrocarbon group can be mentioned.

The upper limit of the content ratio of the other structural units is usually 20 mol%, preferably 10 mol%.

When the polymer [A] is a base polymer, the lower limit of the content of the polymer [A] is usually 70% by mass, preferably 80% by mass, and more preferably 85% by mass in the total solid content of the radiation- .

When the polymer [A] is a water repellent polymer additive, the lower limit of the content of the polymer [A] is usually 0.1% by mass, preferably 0.3% by mass, more preferably 0.5% by mass, in the entire solid content of the radiation sensitive resin composition Do. The upper limit of the content is usually 20% by mass, preferably 15% by mass, and more preferably 10% by mass.

<Method of synthesizing [A] polymer>

The polymer [A] can be synthesized by, for example, polymerizing a monomer giving each structural unit by using a radical polymerization initiator or the like in an appropriate solvent.

As the radical polymerization initiator, for example,

Azobisisobutyronitrile (AIBN), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2-cyclopropylpropionitrile) Azo type radical initiators such as 2,2'-azobis (2,4-dimethylvaleronitrile) and dimethyl 2,2'-azobisisobutyrate;

Peroxide radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide and the like.

As the radical polymerization initiator, AIBN and dimethyl 2,2'-azobisisobutyrate are preferable, and AIBN is more preferable.

These radical initiators may be used alone or in combination of two or more.

As the solvent used for the polymerization, for example,

alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane and n-decane;

Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin and norbornane;

Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene and cumene;

Halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide and chlorobenzene;

Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate and methyl propionate;

Ketones such as acetone, 2-butanone (methyl ethyl ketone), 4-methyl-2-pentanone and 2-heptanone;

Ethers such as tetrahydrofuran, dimethoxy ethane and diethoxy ethane;

And alcohols such as methanol, ethanol, 1-propanol, 2-propanol and 4-methyl-2-pentanol.

As the solvent to be used for the polymerization, ketones are preferable, and 2-butanone is more preferable.

The solvents used in these polymerization may be used alone or in combination of two or more.

The lower limit of the reaction temperature in the polymerization is usually 40 占 폚, preferably 50 占 폚. The upper limit of the reaction temperature is usually 150 占 폚, preferably 120 占 폚. On the other hand, the lower limit of the reaction time is usually 1 hour and preferably 2 hours. The upper limit of the reaction time is usually 48 hours, preferably 24 hours.

The weight average molecular weight (Mw) of the polymer [A] in terms of polystyrene calculated by gel permeation chromatography (GPC) is not particularly limited, but the lower limit thereof is preferably 1,000, more preferably 2,000, still more preferably 3,000, Particularly preferred. The upper limit of the Mw is preferably 50,000 or less, more preferably 30,000 or less, still more preferably 20,000 or less, and particularly preferably 15,000 or less. By setting the Mw of the polymer [A] within the above range, the spreadability of the radiation sensitive resin composition and the ability to inhibit development defects are improved. If the Mw of the polymer [A] is less than the lower limit described above, a resist film having sufficient heat resistance may not be obtained. If the Mw of the polymer [A] exceeds the upper limit, the developability of the resist film may be lowered.

The upper limit of the ratio (Mw / Mn) of Mw to the polystyrene reduced number average molecular weight (Mn) of the polymer [A] is usually 5, preferably 3, The lower limit of the ratio is usually 1.

The upper limit of the content of the low molecular weight component in the [A] polymer is preferably 0.2% by mass, more preferably 0.1% by mass, and particularly preferably 0.06% by mass. By setting the content of the low molecular weight component within the above range, the development contrast can be further improved. The low molecular weight component means a component having a molecular weight of less than 1,000.

The Mw and Mn of the polymer in the present specification are values measured using gel permeation chromatography (GPC) under the following conditions.

GPC column: 2 G2000HXL, 1 G3000HXL, 1 G4000HXL (above, Toso Co., Ltd.)

Column temperature: 40 DEG C

Elution solvent: tetrahydrofuran (Wako Pure Chemical Industries, Ltd.)

Flow rate: 1.0 mL / min

Sample concentration: 1.0 mass%

Sample injection amount: 100 μL

Detector: differential refractometer

Standard material: monodisperse polystyrene

<[B] Radiation-sensitive acid generator>

[B] The radiation-sensitive 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 and the like, and the solubility in the developer containing the organic solvent of the polymer [A] is lowered. A positive type resist pattern and a negative type resist pattern can be formed. The form of containing the radiation-sensitive acid generator of [B] in the radiation-sensitive resin composition may be a form of a low-molecular compound as described below (hereinafter appropriately referred to as "[B] acid generator" May be in the form of an acid generator inserted as part of the polymer, or may be in both forms.

Examples of the acid generator [B] 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. Specific examples of these onium salt compounds include, for example, the onium salt compounds described in WO2012 / 43684.

As the radiation-sensitive acid generator [B], a compound represented by the following formula (4) is preferable. When the [B] radiation-sensitive acid generator is a compound represented by the following chemical formula (4), it is preferable to form the resist film of an acid generated by exposure, such as by interaction with the structural unit (I) It is considered that the diffusion length in the LWR is more appropriately shortened. As a result, the above-described LWR performance and the like are improved.

In the above formula (4), R ¹⁰ is a monovalent group containing an alicyclic structure having 6 or more reduced numbers or a monovalent group containing an aliphatic heterocyclic structure having 6 or more reduced numbers. And R &lt; ¹¹ &gt; is a fluorinated alkanediyl group having 1 to 10 carbon atoms. X ^{&lt; + &} gt ^; is a monovalent radiation-decomposable onium cation.

As the monovalent group containing an alicyclic structure represented by R ¹⁰ and having a reduced number of 6 or more, for example,

Monocyclic cycloalkyl groups such as a cyclooctyl group, a cyclononyl group, a cyclodecyl group and a cyclododecyl group;

Monocyclic cycloalkenyl groups such as a cyclooctenyl group and a cyclodecenyl group;

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

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

As the monovalent group containing an aliphatic heterocyclic structure having a reduced number of 6 or more and represented by R ¹⁰ , for example,

A group including a lactone structure such as norbornane lactone-diol;

A group including a sultone structure such as a norbornane sultone-diarrhea;

An oxygen atom-containing heterocyclic group such as an oxacycloheptyl group and an oxanorbornyl group;

Nitrogen-containing heterocyclic groups such as an azacyclohexyl group, an azacycloheptyl group and a diazabicyclooctane-yl group;

Thiocycloheptyl group, thianorbornyl group and the like, and the like.

From the viewpoint that the aforementioned diffusion length of the acid becomes more suitable, the lower limit of the number of the reducing water of the group represented by R ¹⁰ is preferably 8, more preferably 9, and further preferably 10. The upper limit of the reduced water is preferably 15, more preferably 13.

R ¹⁰ is provided between the in the range that does not impair the effect of the present invention, the reduced water and a monovalent group of reduced water over 6 comprises a cycloaliphatic structure of 6 or more aliphatic heterocyclic structure and R ^11, -COO-, -OCO-, - SO ₂ -, and the like.

As R ¹⁰ , a group represented by the following formulas (f-1) to (f-4) is preferable from the viewpoint that the diffusion length of an acid generated by exposure in the resist film is more appropriately shortened.

In the above formulas (f-1) to (f-4), each * is a bonding hand.

As the fluorinated alkanediyl group having 1 to 10 carbon atoms represented by R ¹¹ , for example, one or more hydrogen atoms of an alkanediyl group having 1 to 10 carbon atoms such as a methanediyl group, an ethanediyl group, a propanediyl group, And an atom-substituted group.

Examples of alkanediyl group fluorinated Al having 1 to 10 carbon atoms represented by R ^11, in view of these in which the shorter the diffusion length in the resist film of the acid more properly generated by exposure, SO ₃ ^- fluorine atoms to the carbon atom adjacent groups A fluorinated alkanediyl group in which two fluorine atoms are bonded to a carbon atom adjacent to the SO ₃ ^- group is more preferable, and a fluorinated alkanediyl group in which 1,1-difluoromethanediyl group, 1,1-difluoromethanediyl group, , 2,2,3,3-hexafluoropropanediyl group and 1,1,3,3,3-pentafluoro-1,2-propanediyl group are more preferable.

The monovalent radiolytic onium cation represented by X ^&lt; ⁺ &gt; is a cation which is decomposed by irradiation with radiation. In the exposure part, sulfonic acid is generated from a proton produced by the decomposition of the radiation-decomposable onium cation and a sulfonate anion. Examples of the monovalent radiation-decomposable onium cation represented by X ^&lt; ⁺ &gt; include a radiation containing an element such as S, I, O, N, P, Cl, Br, F, As, Se, Sn, Sb, And decomposable onium cations. As the cation containing S (sulfur) as an element, for example, a sulfonium cation, a tetrahydrothiophenium cation and the like can be mentioned. Examples of the cation containing I (iodine) as an element include iodonium cation and the like .

X ⁺ is a sulfonium cation represented by the following formula (X-1), a tetrahydrothiophenium cation represented by the following formula (X-2) and a tetrahydrothiophenium cation represented by the following formula (X- Iodonium cation represented by the formula (3) is preferable.

In formula (X-1), R ^a1 , R ^a2 and R ^a3 each independently represent a substituted or unsubstituted, linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted 6 to 12 carbon atom An aromatic hydrocarbon group, -OSO ₂ -R ^P or -SO ₂ -R ^Q , or a cyclic structure in which two or more of these groups are joined together. R ^P And R ^Q each independently represents a substituted or unsubstituted, linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted C6- 12 aromatic hydrocarbon group. k1, k2 and k3 are each independently an integer of 0 to 5; R ^a1 To R ^a3 and R ^P and R ^Q are respectively plural, a plurality of R ^a1 to R ^a3 and R ^P and R ^Q may be the same or different.

In formula (X-2), R ^b1 is a substituted or unsubstituted, linear or branched alkyl group having 1 to 8 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms. k4 is an integer of 0 to 7; When R ^b1 multiple individuals, of R ^b1 and the plurality may be the same or different, a plurality of R ^b1 may represent a ring structure consisting combined with each other. R ^b2 is a substituted or unsubstituted, linear or branched alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms. k5 is an integer of 0 to 6; R ^b2 multiple individual case, of R ^b2 has a plurality may be the same or different, a plurality of R ^b2 may represent a ring structure consisting combined with each other. q is an integer of 0 to 3;

In the formula (X-3), R ^c1 and R ^c2 each independently represent a substituted or unsubstituted, linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms , -OSO ₂ -R ^R or -SO ₂ -R ^S , or represents a ring structure composed of two or more of these groups combined together. Each of ^{R 1} and R ² independently represents a substituted or unsubstituted, linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted carbon number 6 to 12 aromatic hydrocarbon groups. k6 and k7 are each independently an integer of 0 to 5; ^{R c1,} R ^c2, R R and R ^S when the respective plurality of individual, a plurality of ^{R c1,} R ^c2, R R and R ^S may be the same or may each be different.

Examples of the unsubstituted straight-chain alkyl group represented by R ^a1 to R ^a3 , R ^b1 , R ^b2 , R ^c1 and R ^c2 include a methyl group, an ethyl group, a n-propyl group, .

Examples of the unsubstituted branched alkyl group represented by R ^a1 to R ^a3 , R ^b1 , R ^b2 , R ^c1 and R ^c2 include i-propyl, i-butyl, sec- And the like.

As the unsubstituted aromatic hydrocarbon group represented by R ^a1 to R ^a3 , R ^c1 and R ^c2 , for example,

An aryl group such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, or a naphthyl group;

And aralkyl groups such as a benzyl group and a phenethyl group.

Examples of the unsubstituted aromatic hydrocarbon group represented by R ^b1 and R ^b2 include a phenyl group, a tolyl group, and a benzyl group.

Examples of the substituent which may be substituted for the hydrogen atom of the alkyl group and the aromatic hydrocarbon group include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, A carbonyl group, an alkoxycarbonyloxy group, an acyl group, an acyloxy group and the like.

As the substituent, a halogen atom is preferable, and a fluorine atom is more preferable.

As the R ^a1 to R ^a3 , R ^b1 , R ^b2 , R ^c1 and R ^c2 , an unsubstituted straight or branched alkyl group, a fluorinated alkyl group, an unsubstituted monovalent aromatic hydrocarbon group, -OSO ₂ -R " SO ₂ -R "is preferable, a fluorinated alkyl group and an unsubstituted monovalent aromatic hydrocarbon group are more preferable, and a fluorinated alkyl group is more preferable. R "is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

As k1, k2 and k3 in the formula (X-1), an integer of 0 to 2 is preferable, and 0 and 1 are more preferable, and 0 is more preferable.

The k4 in the formula (X-2) is preferably an integer of 0 to 2, more preferably 0 and 1, and even more preferably 1. k5 is preferably an integer of 0 to 2, more preferably 0 and 1, and even more preferably 0.

As k6 and k7 in the formula (X-3), an integer of 0 to 2 is preferable, 0 and 1 are more preferable, and 0 is more preferable.

As X ⁺ , sulfonium cations represented by the formula (X-1) are more preferable, and triphenylsulfonium cations are more preferable from the viewpoint of higher radioactive sensitivity among them.

The compound represented by the formula (4) is preferably a compound represented by the following formulas (g-1) to (g-4) from the viewpoint that an acid can be more easily generated by exposure.

When the [B] radiation-sensitive acid generator is [B] an acid generator, the lower limit of the content of the [B] radiation-sensitive acid generator is preferably [ A] is preferably 0.1 part by mass, more preferably 0.5 part by mass, and further preferably 1 part by mass, per 100 parts by mass of the polymer. The upper limit of the content is preferably 30 parts by mass, more preferably 20 parts by mass, still more preferably 15 parts by mass. When the content of the [B] acid generator is within the above range, the sensitivity and developability of the radiation sensitive resin composition are improved.

[B] The radiation-sensitive acid generator may be used alone or in combination of two or more.

<[C] Acid diffusion controller>

The radiation-sensitive resin composition may contain an acid diffusion control agent [C], if necessary. [C] The acid diffusion control member is preferably used to control the diffusion phenomenon in the resist film of the acid generated from the [B] radiation-sensitive acid generator by exposure and suppress the undesired chemical reaction in the non- Effect. Further, the storage stability of the obtained radiation-sensitive resin composition is further improved, the resolution as a resist is further improved, and the change in the line width of the resist pattern due to the variation in the post-exposure delay time from exposure to development processing can be suppressed , A radiation sensitive resin composition having excellent process stability can be obtained. The content of [C] acid diffusion control agent in the radiation sensitive resin composition may be in the form of a free compound (hereinafter appropriately referred to as "[C] acid diffusion control agent"), Or may be in the form of both of them.

As the acid diffusion control agent, for example, a compound represented by the following formula (6) (hereinafter also referred to as a "nitrogen-containing compound (I)"), a compound having two nitrogen atoms in the same molecule Nitrogen containing compound (II) "), a compound having three nitrogen atoms (hereinafter also referred to as" nitrogen containing compound (III) "), amide group containing compound, urea compound and nitrogen containing heterocyclic compound Compounds and the like.

In the above formula (6), R ¹² , R ¹³ and R ¹⁴ are each independently a hydrogen atom, an optionally substituted straight chain, branched or cyclic alkyl group, an aryl group or an aralkyl group.

As the nitrogen-containing compound (I), for example,

monoalkyl amines such as n-hexyl amine;

Dialkylamines such as di-n-butylamine;

Trialkylamines such as triethylamine and tri-n-pentylamine;

And aromatic amines such as aniline and 2,6-diisopropylaniline.

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

As the nitrogen-containing compound (III), for example,

Polyamine compounds such as polyethyleneimine and polyallylamine;

And polymers such as dimethylaminoethyl acrylamide.

Examples of the amide group-containing compound include, but are not limited to, formaldehyde, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, N-methylpyrrolidone, and the like.

Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tributylthiourea And the like.

As the nitrogen-containing heterocyclic compound, for example,

Pyridines such as pyridine and 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 an acid dissociable group include Nt-butoxycarbonylpiperidine, Nt-butoxycarbonylimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycar (T-butoxycarbonyl) diethanolamine, N- (t-butoxycarbonyl) di-n-octylamine, N- N-tert-butoxycarbonyl-4-hydroxypiperidine, Nt-amyloxycarbonyl-4-hydroxypiperidine, and the like can be used. .

As the acid diffusion control agent [C], a photodegradable base which generates a weak acid upon exposure by exposure may also be used. Examples of the photodegradable base include an onium salt compound decomposed by exposure to lose acid diffusion controllability and the like.

Examples of the onium salt compound include a sulfonium salt compound represented by the following formula (7-1), an iodonium salt compound represented by the following formula (7-2), a salicylate salt compound represented by the following formula (7-3) And the like.

In formulas (7-1) and (7-2), R ¹⁵ to R ¹⁹ each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group or a halogen atom. E ^-, and Q ^- are each independently selected from OH ^- is an anion represented by the formula or ^{(7-3) -, R β -COO} -, R β -SO 3. Provided that R ^? Is an alkyl group, an aryl group or an aralkyl group.

In the formula (7-3), R ²⁰ represents a linear or branched alkyl group having 1 to 12 carbon atoms which may partially or wholly be substituted with a fluorine atom, or a linear or branched alkyl group having 1 to 12 carbon atoms Lt; / RTI &gt; u is an integer of 0 to 2;

Examples of the onium salt compound include compounds represented by the following formulas (h-1) to (h-6).

The nitrogen-containing compound (I), the nitrogen-containing heterocyclic compound, the sulfonium salt compound represented by the formula (7-1) and the sulfonium salt compound represented by the formula (7-3) are preferable, and tri-n-pentylamine, 2,6-diisopropylaniline, N- (undecylcarbonyloxyethyl) morpholine, h-1) and the compound represented by the above formula (h-2) are more preferable.

When the radiation-sensitive resin composition contains the acid diffusion control agent [C], when the acid diffusion control agent is the acid diffusion control agent [C], the lower limit of the content of the acid diffusion control agent [C] ] Is preferably 0.1 part by mass, more preferably 0.3 part by mass, per 100 parts by mass of the polymer. The upper limit of the content is preferably 20 parts by mass, more preferably 15 parts by mass, further preferably 10 parts by mass. When the content of the [C] acid diffusion controlling agent exceeds the upper limit, the sensitivity of the radiation sensitive resin composition may be lowered.

[C] The acid diffusion control element may be used alone or in combination of two or more.

<[D] Polymer>

The [D] polymer is a fluorine atom-containing polymer (excluding those corresponding to the polymer [A]). When the resist film is formed by the radiation-sensitive resin composition containing the [D] polymer, the distribution thereof tends to be localized near the surface of the resist film due to the oil property of the fluorine-containing polymer in the film, It is possible to prevent the acid generator, the acid diffusion controller, and the like from leaching into the immersion medium. Further, the advancing contact angle between the resist film and the immersion medium can be controlled to a desired range by the water repellency characteristic of the [D] polymer, and occurrence of bubble defects can be suppressed. Further, the contact angle of the resist film and the liquid immersion medium with respect to the retreat becomes high, so that scanning exposure can be performed at a high speed without leaving water droplets. When the radiation-sensitive resin composition contains the [D] polymer in this way, a resist film suitable for liquid immersion lithography can be formed.

The [D] polymer is not particularly limited as long as it is a polymer having a fluorine atom, but it is preferable that the content of fluorine atoms (mass%) is higher than that of the polymer [A] in the radiation sensitive resin composition. When the content of fluorine atoms is higher than that of the polymer [A], the degree of the above-described unevenization becomes higher, and the properties such as water repellency and dissolution inhibiting property of the obtained resist film are improved.

The lower limit of the fluorine atom content of the [D] polymer is preferably 1% by mass, more preferably 2% by mass, still more preferably 4% by mass, and particularly preferably 7% by mass. The upper limit of the fluorine atom content is preferably 60% by mass, more preferably 40% by mass, still more preferably 30% by mass. If the fluorine atom content of the [D] polymer is less than the above lower limit, the hydrophobicity of the surface of the resist film may be lowered. The fluorine atom content (% by mass) of the polymer can be calculated from the structure of the polymer obtained by ¹³ C-NMR spectrum measurement.

As the [D] polymer, it is preferable to have at least one member selected from the group consisting of the following structural unit (Da) and structural unit (Db). The [D] polymer may have one structural unit (Da) or two structural units (Db), or two or more structural units (Db).

[Structural unit (Da)]

The structural unit (Da) is a structural unit represented by the following formula (8a). [D] The polymer can have a fluorine atom content by adjusting the structural unit (Da).

In the above formula (8a), R ^D is a hydrogen atom, a methyl group or a trifluoromethyl group. G is a single bond, oxygen, _{sulfur, -CO-O-, -SO 2 -O} -NH-, -CO-NH- or -O-CO-NH-. R ^E is a monovalent straight chain hydrocarbon group of 1 to 6 carbon atoms having at least one fluorine atom or a monovalent aliphatic cyclic hydrocarbon group of 4 to 20 carbon atoms having at least one fluorine atom.

Examples of the chain hydrocarbon group having at least one fluorine atom and having 1 to 6 carbon atoms represented by R ^E include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, 3,3,3-pentafluoropropyl group, 1,1,1,3,3,3-hexafluoropropyl group, perfluoro n-propyl group, perfluoro i-propyl group, perfluoro n -Butyl group, a perfluoro i-butyl group, a perfluoro t-butyl group, a 2,2,3,3,4,4,5,5-octafluoropentyl group, a perfluorohexyl group, etc. .

Examples of the aliphatic cyclic hydrocarbon group having 4 to 20 carbon atoms and having at least one fluorine atom represented by R ^E include a monofluorocyclopentyl group, a difluorocyclopentyl group, a perfluorocyclopentyl group, a monofluoro A perfluorocyclohexylmethyl group, a fluoronorbornyl group, a fluoroamantyl group, a fluorobornyl group, a fluoroisobornyl group, a fluoro-tricyclodecyl group, a fluorotetracyclo-cyclohexyl group, Decyl groups, and the like.

Examples of the monomer giving the structural unit (Da) include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,2-trifluoroethyl (Meth) acrylate, perfluoro (meth) acrylate, perfluoro n-propyl (meth) acrylate, perfluoro i-propyl (meth) acrylate, perfluoro n-butyl (Meth) acrylate, perfluoro (meth) acrylate, perfluoro t-butyl (meth) acrylate, 2- (1,1,1,3,3,3-hexafluoropropyl) (Meth) acrylic acid ester, 1- (2,2,3,3,4,4,5,5-octafluoropentyl) (meth) acrylic acid ester, perfluorocyclohexylmethyl (meth) (Meth) acrylate, monofluorocyclopentyl (meth) acrylate, di (2, 3, (Meth) acrylate, perfluorocyclopentyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, perfluorocyclopentyl (meth) acrylate, perfluorocyclohexyl (Meth) acrylate, fluoroisobornyl (meth) acrylate, fluoroaryl (meth) acrylate, fluoroboronyl (meth) acrylate, Decyl (meth) acrylate, fluorotetracyclodecyl (meth) acrylate, and the like.

As the monomer giving the structural unit (Da), 2,2,2-trifluoroethyl (meth) acrylate is preferable.

The lower limit of the content of the structural unit (Da) is preferably 5 mol%, more preferably 10 mol%, and still more preferably 30 mol% based on the total structural units constituting the [D] polymer. The upper limit of the content is preferably 95 mol%, more preferably 90 mol%, still more preferably 85 mol%. By setting such a content ratio, a higher dynamic contact angle on the surface of the resist film during immersion exposure can be exhibited.

[Structural unit (Db)]

The structural unit (Db) is a structural unit represented by the following formula (8b). The hydrophobic property of the [D] polymer is increased by having the structural unit (Db), so that the dynamic contact angle of the surface of the resist film formed of the radiation sensitive resin composition can be further improved.

In the above formula (8b), R ^F is a hydrogen atom, a methyl group or a trifluoromethyl group. R ²¹ is a monovalent hydrocarbon group having 1 to 20 (1 + s), oxygen atom at the terminal of R ²¹ R ²² side, a sulfur atom, -NR'-, carbonyl, -CO-O- or -CO-NH -. &Lt; / RTI &gt; R 'is a hydrogen atom or a monovalent organic group. R ²² is a single bond, a divalent straight chain hydrocarbon group having 1 to 10 carbon atoms, or a divalent aliphatic cyclic hydrocarbon group having 4 to 20 carbon atoms. X ² is a divalent straight chain hydrocarbon group having 1 to 20 carbon atoms and at least one fluorine atom. A ¹ is an oxygen atom, -NR "-, -CO-O- * or -SO ₂ -O- * R" is a hydrogen atom or a monovalent organic group. * Represents a bonding site to be bonded to R &lt; ^{21 &} gt ;. R ²³ is a hydrogen atom or a monovalent organic group. s is an integer of 1 to 3; Provided that when s is 2 or 3, plural R ²² , X ² , A ¹ and R ²³ may be the same or different.

When R ²³ is a hydrogen atom, the solubility of the [D] polymer in an alkali developing solution can be improved.

The monovalent organic group represented by R ²³ includes, for example, an acid dissociable group, an alkali dissociable group, or a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent.

Examples of the structural unit (Db) include structural units represented by the following formulas (8b-1) to (8b-3).

In the formulas (8b-1) to (8b-3), R ^{21 '} is a divalent straight, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms. R ^F , X ² , R ²³ and s are as defined in the above formula (8b). When s is 2 or 3, plural X ² and R ²³ may be the same or different.

When the polymer [D] has the structural unit (8b), the lower limit of the content ratio of the structural unit (8b) is preferably 5 mol% based on the total structural units constituting the polymer [D], more preferably 10 mol% desirable. The upper limit of the content is preferably 90 mol%, more preferably 85 mol%, still more preferably 80 mol%. With such a content ratio, the surface of the resist film formed of the radiation sensitive resin composition can improve the degree of lowering of the dynamic contact angle in the alkali development.

[Structural unit (Dc)]

The polymer [D] may have a structural unit (hereinafter also referred to as a "structural unit (Dc)") containing an acid dissociable group in addition to the structural units (Da) and (Db) Except for the case of When the [D] polymer has the structural unit (Dc), the shape of the obtained resist pattern becomes better. Examples of the structural unit (Dc) include structural units (II) in the above-mentioned [A] polymer.

The lower limit of the content of the structural unit (Dc) is preferably 5% by mole, more preferably 10% by mole, and further preferably 15% by mole based on the total structural units constituting the polymer [D]. The upper limit of the content is preferably 90 mol%, more preferably 70 mol%, still more preferably 60 mol%, and particularly preferably 50 mol%. When the content ratio of the structural unit (Dc) is less than the lower limit described above, the occurrence of development defects in the resist pattern may not be sufficiently suppressed. When the content ratio of the structural unit (Dc) exceeds the upper limit, the hydrophobicity of the resulting resist film surface may be lowered.

[Other structural units]

Further, the [D] polymer may contain, in addition to the structural unit, a structural unit including at least one structure selected from the group consisting of a structural unit containing an alkali-soluble group, a lactone structure, a cyclic carbonate structure and a sultone structure , A structural unit including an alicyclic group, and the like.

Examples of the alkali-soluble group include a carboxy group, a sulfonamide group, and a sulfo group. Examples of the structural unit having at least one structure selected from the group consisting of a lactone structure, a cyclic carbonate structure and a sultone structure include structural units (III) in the above-mentioned [A] polymer.

The upper limit of the content ratio of the other structural units is usually 30 mol% and preferably 20 mol% based on the total structural units constituting the [D] polymer. When the content ratio of the other structural units exceeds the upper limit, the pattern forming property of the radiation-sensitive resin composition may be deteriorated.

The polymer [D] is preferably a polymer containing the structural unit (II) and the structural unit (Da) from the viewpoint of further improving the properties such as water repellency and dissolution inhibiting property of the obtained resist film, A polymer containing a structural unit derived from fluoroethyl methacrylate and a structural unit derived from 1-ethylcyclopentyl methacrylate is more preferable.

When the radiation-sensitive resin composition contains the [D] polymer, the lower limit of the content of the [D] polymer is preferably 0.5 part by mass, more preferably 1 part by mass, per 100 parts by mass of the polymer [A] The mass part is more preferable. The upper limit of the content is preferably 20 parts by mass, more preferably 15 parts by mass, further preferably 10 parts by mass. If the content of the [D] polymer exceeds the upper limit, the pattern-forming properties of the radiation-sensitive resin composition may be deteriorated.

[D] Polymers may be used alone or in combination of two or more.

<Method of synthesizing [D] polymer>

The [D] polymer can be synthesized by a conventional method such as radical polymerization. As the synthesis method, for example, the same method as the synthesis method of the [A] polymer can be given.

The lower limit of the polystyrene-reduced weight average molecular weight (Mw) of the [D] polymer by gel permeation chromatography (GPC) is usually 1,000 and preferably 2,000. The upper limit of the Mw is usually 20,000, preferably 15,000. If the Mw of the [D] polymer exceeds the upper limit, the developability of the radiation-sensitive resin composition may be deteriorated. If the Mw of the [D] polymer is less than the lower limit described above, the heat resistance of the resulting resist film may be lowered.

The upper limit of the ratio (Mw / Mn) of Mw to the number average molecular weight (Mn) converted to polystyrene by the GPC of the [D] polymer is usually 5, preferably 3, and more preferably 2. The lower limit of the ratio is usually 1. If Mw / Mn exceeds the upper limit, the heat resistance of the resulting resist film may be lowered.

<[E] Polymer>

The radiation-sensitive resin composition may optionally contain other polymer ([E] polymer) as a polymer component other than the [A] polymer and the [D] polymer.

As the [E] polymer, for example, a polymer containing the structural unit (II) and the structural unit (III) described above as the structural unit may, for example, be mentioned.

When the radiation sensitive resin composition contains the polymer [A] as the water repellent polymer additive, it is preferable that the polymer [E] is contained as the base polymer. In this case, it is preferable that the [E] polymer has the structural unit (II) and the structural unit (III).

When the polymer [A] is a water repellent polymer additive, the lower limit of the content of the [E] polymer in the radiation-sensitive resin composition is preferably 10 parts by mass, more preferably 50 parts by mass or more per 100 parts by mass of the polymer [A] And more preferably 100 parts by mass. The upper limit of the content is preferably 10,000 parts by mass, more preferably 1,500 parts by mass, and even more preferably 1,000 parts by mass. If the content of the [E] polymer exceeds the upper limit, the pattern-forming property of the radiation-sensitive resin composition may be deteriorated.

[E] Polymers may be used singly or in combination of two or more.

<Method for synthesizing [E] polymer>

[E] The polymer can be synthesized by a conventional method such as radical polymerization. As the synthesis method, for example, the same method as the synthesis method of the [A] polymer can be given.

<[F] Solvent>

The radiation-sensitive resin composition usually contains a [F] solvent. The [F] solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least the [A] polymer, the [B] radiation-sensitive acid generator, and the [C] acid diffusion control agent or the like, if necessary.

Examples of the [F] solvent include an alcohol solvent, an ether solvent, a ketone organic solvent, an amide solvent, an ester organic solvent and a hydrocarbon solvent.

As the alcoholic solvent, for example,

Propanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, Butanol, 2-ethylhexanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol , sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, secundecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, Monoalcohol solvents such as furyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol and diacetone alcohol;

Propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4- Polyhydric alcohol solvents such as 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol and tripropylene glycol;

Ethylene glycol monoethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol mono Methyl ethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene Glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and dipropylene glycol monopropyl ether; and the like.

As the ether-based solvent, for example,

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

Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;

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

As the ketone-based solvent, for example,

Propyl ketone, methyl n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, 2-heptanone (methyl-n-pentyl ketone), ethyl- , Methyl-n-hexyl ketone, di-iso-butyl ketone, and trimethyl nonanone;

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

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

Examples of the amide solvent include cyclic amide solvents such as N, N'-dimethylimidazolidinone and N-methylpyrrolidone;

A chain amide type such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, Solvents, and the like.

As the ester-based solvent, for example,

Propyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-pentyl acetate, i-pentyl acetate, sec-pentyl acetate, acetic acid 3-methylacetate Acetoxy-based solvents such as acetonitrile, propionitrile, propionitrile, propionitrile, propionitrile, propionitrile, propionitrile,

Ethylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, Polyhydric alcohol partial ether acetate type solvents such as monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate and dipropylene glycol monoethyl ether acetate;

Carbonate solvents such as diethyl carbonate and the like;

Butyl acetate, methyl acetoacetate, ethyl acetoacetate, methyl lactate, ethyl lactate, n-butyl lactate, n-butyl acetate, isopropyl acetoacetate, isopropyl acetoacetate, -Butyl, n-amyl lactate, diethyl malonate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate and the like.

As the hydrocarbon-based solvent, for example,

aliphatic alcohols such as n-pentane, iso-pentane, n-hexane, isohexane, n-heptane, isoheptane, 2,2,4-trimethylpentane, n-octane, iso-octane, cyclohexane and methylcyclohexane Hydrocarbon solvents;

Benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, isopropylbenzene, diethylbenzene, isobutylbenzene, triethylbenzene, di- And aromatic hydrocarbon solvents such as amylnaphthalene.

As the [F] solvent, ester solvents and ketone solvents are preferable from the viewpoint of better solubility or dispersibility among them, more preferred are polyhydric alcohol partial ether acetate solvents and cyclic ketone solvents, and propylene glycol monomethyl ether Acetate and cyclohexanone are more preferred.

The radiation-sensitive resin composition may contain one or two or more [F] solvents.

<[G] Sedimentation accelerator>

The unidirectional accelerator has the effect of segregating the polymer [D] more efficiently on the surface of the resist film, when the radiation-sensitive resin composition contains the [D] polymer. By incorporating the unidirectional accelerator into the radiation sensitive resin composition, the amount of the [D] polymer added can be made smaller than in the prior art. Therefore, the dissolution of components from the resist film into the immersion liquid can be further suppressed without impairing the resist basic characteristics such as LWR performance, development defects, pattern collapse resistance, and the like, and the immersion exposure can be performed at a higher speed by the high-speed scanning And as a result, the hydrophobicity of the surface of the resist film for suppressing defects due to immersion such as watermark defects can be improved. Examples of such a polymerization accelerator include a low molecular weight compound having a relative dielectric constant of 30 or more and 200 or less and a boiling point of 100 占 폚 or more at 1 atm. Specific examples of such compounds include lactone compounds, cyclic carbonate compounds, nitrile compounds, and polyhydric alcohols.

Examples of the lactone compound include? -Butyrolactone, valerolactone, mevalonic lactone and norbornane lactone.

Examples of the cyclic carbonate compound include propylene carbonate, ethylene carbonate, butylene carbonate, and vinylene carbonate.

Examples of the nitrile compound include succinonitrile and the like.

Specific examples of the polyhydric alcohol include, for example, glycerin.

Of these, as the [G] unilateralization accelerator, a lactone compound is preferable, and γ-butyrolactone is more preferable from the viewpoint of having an effect of segregating on the resist film surface more efficiently.

The [G] unilateralization accelerator may be used alone or in combination of two or more.

<Other optional components>

The radiation-sensitive resin composition may contain other optional components in addition to the components [A] to [G]. Other optional components include, for example, surfactants, alicyclic skeleton-containing compounds, and sensitizers. These other optional components may be used individually or in combination of two or more.

(Surfactants)

The surfactant exhibits the effect of improving the coatability, stretching, developability and the like. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol di And nonionic surfactants such as polyethylene glycol distearate.

Examples of commercially available products include "KP341" manufactured by Shin Etsu Chemical Co., Ltd., "Polyflow No. 75" manufactured by Kyoe Shagaku Co., Ltd., "Polyflow No. 95" manufactured by the company, "Epshot EF301" manufactured by TOKEM PRODUCTS, Megaface F171 "by DIC," Megaface F173 "by the company," Fluorad FC430 "by Sumitomo 3M," Fluorad FC431 "by the company," Asahi Glass Co., The company's Surplon SC-101, the company's Surplon SC-102, the company's Surplon SC-103, and the company's "Surplus SC-101" Ron SC-SC-104 ", the company's" Suffron SC-105 ", and the company's" Suffron SC-106 ".

The content of the surfactant in the radiation sensitive resin composition is usually 2 parts by mass or less based on 100 parts by mass of the polymer [A].

(Alicyclic skeleton-containing compound)

The alicyclic skeleton-containing compound exerts the effect of improving dry etching resistance, pattern shape, adhesion with a substrate, and the like.

As the alicyclic skeleton-containing compound, for example,

Adamantane derivatives such as 1-adamantanecarboxylic acid, 2-adamantanone and t-butyl 1-adamantanecarboxylate;

Deoxycholic acid esters such as t-butyl deoxycholate, t-butoxycarbonylmethyl deoxycholate and 2-ethoxyethyl deoxycholate;

Acid esters such as t-butyl dicarbonate, t-butyl dicarbonate, t-butyl dicarbonate, t-butyl dicarbonate, t-butoxycarbonyl methyl dicarbonate and 2-ethoxyethyl dicarbonate;

Ethyl] tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] dodecane, 2-hydroxy-9-methoxycarbonyl (2-hydroxy-2,2- Oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nonane. The content of the alicyclic skeleton-containing compound in the radiation-sensitive resin composition is usually 5 parts by mass or less based on 100 parts by mass of the polymer [A].

(Sensitizer)

The sensitizer exhibits an action of increasing the amount of acid generated from [B] acid generator and the like, and exhibits the effect of improving the &quot; apparent sensitivity &quot; of the radiation sensitive resin composition.

Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, nonacetyls, eosin, rose bengals, pyrenes, anthracenes, phenothiazines and the like. These sensitizers may be used alone or in combination of two or more. The content of the sensitizer in the radiation-sensitive resin composition is usually 2 parts by mass or less based on 100 parts by mass of the polymer [A].

&Lt; Method for producing radiation-sensitive resin composition >

The radiation-sensitive resin composition may contain, for example, a suitable component such as [A] polymer, [B] radiation-sensitive acid generator, [C] acid diffusion controller, optional components contained as needed, and [F] In a predetermined ratio. After mixing, the radiation sensitive resin composition is preferably filtered, for example, with a filter having a pore size of about 0.2 mu m. The lower limit of the solid content concentration of the radiation-sensitive resin composition is usually 0.1% by mass, preferably 0.5% by mass, and more preferably 1% by mass. The upper limit of the solid content concentration is usually 50% by mass, preferably 30% by mass, and more preferably 20% by mass.

<Method of Forming Resist Pattern>

In the resist pattern forming method,

A step of forming a resist film (hereinafter also referred to as a &quot; resist film forming step &quot;),

A step of exposing the resist film (hereinafter also referred to as &quot; exposure step &quot;), and

The step of developing the exposed resist film (hereinafter also referred to as &quot; developing step &

The resist pattern forming method comprising:

Wherein the resist film is formed of the radiation-sensitive resin composition.

According to the resist pattern forming method, since the above radiation-sensitive resin composition is used, the above-described LWR performance and the like are improved. Hereinafter, each process will be described.

[Resist film forming step]

In this step, a resist film is formed from the radiation-sensitive resin composition. As the substrate on which the resist film is formed, conventionally known ones such as silicon wafers, silicon dioxide, wafers coated with aluminum, and the like can be given. In addition, an organic or inorganic antireflection film disclosed in, for example, Japanese Patent Application Laid-Open No. 6-12452 and Japanese Patent Application Laid-Open No. 59-93448 can be formed on a substrate. Examples of the application method include spin coating (spin coating), soft coating, and roll coating. After the coating, pre-baking (PB) may be performed to volatilize the solvent in the coating film if necessary. The lower limit of the PB temperature is usually 60 占 폚, preferably 80 占 폚. The upper limit of the PB temperature is usually 140 占 폚, preferably 120 占 폚. The lower limit of the PB time is usually 5 seconds, preferably 10 seconds. The upper limit of the PB time is usually 600 seconds, preferably 300 seconds. The lower limit of the film thickness of the formed resist film is preferably 10 nm. The upper limit of the film thickness is preferably 1,000 nm, more preferably 500 nm.

In the case of performing liquid immersion exposure, in the case where the radiation sensitive resin composition does not contain a water repellent polymer additive, in order to avoid direct contact between the immersion liquid and the resist film on the formed resist film, An insoluble immersion protective film may be formed. Examples of the immersion protective film include a solvent peelable protective film (see, for example, Japanese Patent Laid-Open No. 2006-227632) that is peeled off by a solvent before the step (3), a developer peelable protective film For example, International Publication No. 2005/069076, International Publication No. 2006/035790). However, from the viewpoint of the amount of work, it is preferable to use a protective film for liquid immersion for developer.

[Exposure step]

In this step, exposure is performed by exposing the resist film formed in the step (1) to exposure light through a photomask (possibly through an immersion medium such as water). Examples of the exposure light include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-ray and? -Ray, charged particle beams such as? -Ray and the like depending on the line width of a target pattern. Of these, far ultraviolet rays and electron beams are preferable, and ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm) and electron beam are more preferable, and ArF excimer laser light and electron beam are more preferable.

When the exposure is carried out by immersion exposure, examples of the immersion liquid to be used include water and a fluorine-based inactive liquid. The liquid immersion liquid is preferably transparent to the exposure wavelength and is preferably as small as possible as long as the temperature coefficient of the refractive index is minimized so as to minimize the distortion of the optical image projected onto the film. Particularly when the exposure light source is the ArF excimer laser light (wavelength 193 nm) , It is preferable to use water in terms of ease of acquisition and easiness of handling in addition to the above-described viewpoints. When water is used, it is also possible to add a small amount of an additive for increasing the surface activity, while reducing the surface tension of the water. It is preferable that the additive does not dissolve the resist film on the wafer and can neglect the influence on the optical coating of the lens underside. As the water to be used, distilled water is preferable.

After the exposure, post-exposure baking (PEB) is performed to remove dissociation of the acid dissociable group in the polymer [A] due to the acid generated from the [B] radiation-sensitive acid generator by exposure in the exposed portion of the resist film . With this PEB, there is a difference in solubility in the developing solution between the exposed portion and the unexposed portion. The lower limit of the PEB temperature is usually 50 占 폚, and more preferably 80 占 폚. The upper limit of the PEB time is usually 180 占 폚, preferably 130 占 폚. The lower limit of the PEB time is usually 5 seconds, preferably 10 seconds. The upper limit of the PEB time is usually 600 seconds, preferably 300 seconds.

[Development process]

In this step, the resist film exposed in step (2) is developed. Thus, a predetermined resist pattern can be formed. After development, it is generally washed with a rinsing liquid such as water or alcohol, and dried.

Examples of the developing solution used in the development include alkali metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di- , Triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7 -Undecene, 1,5-diazabicyclo- [4.3.0] -5-nonene, and the like can be given. Among them, TMAH aqueous solution is preferable, and 2.38 mass% TMAH aqueous solution is more preferable.

In the case of organic solvent development, an organic solvent such as a hydrocarbon solvent, an ether solvent, an ester solvent, a ketone solvent or an alcohol solvent, or a solvent containing an organic solvent may, for example, be mentioned. As the organic solvent, for example, one kind or two or more kinds of solvents listed as [F] solvents of the above radiation-sensitive resin composition can be mentioned. Of these, ester-based solvents and ketone-based solvents are preferred. As the ester-based solvent, acetic acid ester-based solvent is preferable, and n-butyl acetate is more preferable. As the ketone solvent, a chain ketone is preferable, and 2-heptanone is more preferable. The lower limit of the content of the organic solvent in the developer is preferably 80% by mass, more preferably 90% by mass, still more preferably 95% by mass, and particularly preferably 99% by mass. Examples of components other than the organic solvent in the developer include water and silicone oil.

Examples of the developing method include a method (dipping method) in which the substrate is immersed in a tank filled with a developer for a predetermined time (dipping method), a method in which the developing solution is raised by surface tension on the surface of the substrate, A method of spraying a developer on the surface (spray method), a method of continuously developing a developer while scanning a developer-dispensing nozzle at a constant speed on a substrate rotating at a constant speed (dynamic dispensing method), and the like .

<Examples>

Hereinafter, the present invention will be described concretely based on examples, but the present invention is not limited to these examples. Methods for measuring various physical properties are shown below.

[Mw and Mn]

Mw and Mn of the polymer were measured by GPC under the following conditions.

GPC column: 2 G2000HXL, 1 G3000HXL, 1 G4000HXL (above, Toso Co., Ltd.)

Column temperature: 40 DEG C

Elution solvent: tetrahydrofuran (Wako Pure Chemical Industries, Ltd.)

Flow rate: 1.0 mL / min

Sample concentration: 1.0 mass%

Sample injection amount: 100 μL

Detector: differential refractometer

Standard material: monodisperse polystyrene

[Content of low molecular weight component (% by mass)]

(Analysis) of an eluent: acrylonitrile / 0.1% phosphoric acid aqueous solution at a flow rate of 1.0 mL / min using an Inertsil ODS-25 占 퐉 column (4.6 mm? X 250 mm) Chromatography (HPLC). The low molecular weight component means a component containing a monomer as a main component, and more specifically, a component having a molecular weight of less than 1,000, preferably a component having a molecular weight of not more than that of a trimer.

[ ¹³ C-NMR analysis]

^{The 13} C-NMR analysis was performed using a nuclear magnetic resonance apparatus ("JNM-ECX400" manufactured by Nippon Denshoku Co., Ltd.) and deuterated chloroform as a measurement solvent.

&Lt; Preparation of compound &

[Example 1] (Preparation of compound (M-1)

(Synthesis of compound (m-1)

4.25 g (65.0 mmol) of zinc powder, 50 mL of dehydrated tetrahydrofuran and 0.272 g (2.5 mmol) of chlorotrimethylsilane were added to a 300 mL eggplant-shaped flask, and the mixture was stirred at 35 캜 for 15 minutes. A solution prepared by dissolving 7.10 g (50.0 mmol) of? -Acetyl-? -Methyl-? -Butyrolactone and 13.7 g (55.0 mmol) of 1-ethylcyclohexyl bromoacetate in 40 mL of dehydrated tetrahydrofuran was slowly added thereto And added. At this time, the solution temperature was raised by the reaction heat, but the dropping rate was adjusted so that the inner temperature became 45 캜 or lower. After completion of the dropwise addition, the mixture was stirred at 35 DEG C for 5 hours, and the disappearance of the raw material was confirmed by TLC. After the reaction was stopped with an aqueous solution of ammonium chloride, the precipitate was removed by filtration through Celite. After the solvent was replaced with ethyl acetate, the reaction mixture was washed with water. The solvent was distilled off and purified by column chromatography to obtain 13.9 g (m-1) (yield: 89%). The obtained compound (m-1) was analyzed by LC-MS, and M ⁺ = 312 was confirmed.

(Synthesis of compound (M-1)

12.5 g (40.0 mmol) of (m-1), 0.244 g (2.00 mmol) of N, N-dimethylaminopyridine, 6.07 g (60.0 mmol) of triethylamine and 50 mL of dehydrated acetonitrile were added to a 200 mL eggplant- After the addition, the mixture was cooled in an ice water bath to 0 占 폚. Then, 4.60 g (44.0 mmol) of methacryloyl chloride was added dropwise thereto. The mixture was stirred at 0 占 폚 for 1 hour and then at room temperature for 6 hours. After disappearance of the starting material was confirmed by TLC, the reaction was stopped by adding water. The reaction mixture was extracted with ethyl acetate, washed with water and purified by column chromatography to obtain 12.6 g (yield: 83%) of a compound represented by the following formula (M-1). The obtained compound (M-1) was analyzed by LC-MS, and M ⁺ = 380 was confirmed.

[Examples 2 to 59] (Preparation of compounds (M-2 to 59)) [

(M-2) to (m-59) were used instead of the compound represented by the following formula (m-1) as the raw materials in Example 1, To obtain the compounds represented by the formulas (M-2) to (M-59), respectively. When X is a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms among the compounds represented by the formula (5),? -Acetyl-? -Methyl- (M-2) to (M-59) were prepared from the above compound in the same manner as in Example 1, except that γ-butyrolactone and 1-ethylcyclohexyl bromoacetate were appropriately selected as the raw materials, Respectively. The obtained compound was analyzed by LC-MS, and it was confirmed that the obtained compound was the target compound.

[Example 60] (Preparation of compound (M-60)) [

(65 mmol) of zinc powder, 50 mL of dehydrated tetrahydrofuran, and 0.272 g (2.5 mmol) of chlorotrimethylsilane were added to a 300 mL three-necked flask purged with nitrogen, and the mixture was stirred at 35 DEG C for 15 minutes. A solution prepared by dissolving 14.8 g (50 mmol) of the compound represented by the following formula (m-60) and 13.7 g (55 mmol) of ethyl (2-bromomethyl) methacrylate in 40 mL of tetrahydrofuran was slowly added thereto And added. At this time, the solution temperature was raised by the reaction heat, but the dropping rate was adjusted so that the inner temperature became 45 캜 or lower. After completion of the dropwise addition, the mixture was stirred at 35 DEG C for 5 hours, and the disappearance of the raw material was confirmed by TLC. Subsequently, a saturated aqueous solution of ammonium chloride was added to stop the reaction. The resulting salt was removed by filtration with Celite, extracted with ethyl acetate, washed with water and purified by column chromatography to obtain 16.2 g (yield 89%) of a compound represented by the following formula (M-60) ). The obtained compound (M-60) was analyzed by LC-MS, and M ⁺ = 365.43 was confirmed.

[Examples 61 to 68] (Preparation of compounds (M-61) to (M-68)

In the same manner as in Example 60 except that the compound represented by the following formula (m-61) to (m-68) was used as a raw material in place of the compound represented by the following formula (m-60) To obtain the compounds represented by the formulas (M-61) to (M-68), respectively. The obtained compound was analyzed by LC-MS, and it was confirmed that the obtained compound was the target compound.

&Lt; Synthesis of Polymer &

The respective compounds used in the synthesis of the [A] polymer, the [D] polymer and the [E] polymer other than the compounds represented by the above (M-1) to (M-68) are shown below.

The compounds (M'-1) to (M'-17) can be obtained by reacting the structural unit (II) -27) each give a structural unit containing a fluorine atom.

&Lt; Preparation of Base Polymer ([A] Polymer and [E] Polymer)

[Synthesis Example 1] (Production of polymer (E-1)

10.63 g (60 mol%) of the compound (M'-1) and 9.37 g (40 mol%) of the compound (M'-20) were dissolved in 40 g of 2-butanone, and 0.87 g of AIBN Mol%) was added to prepare a monomer solution. Subsequently, a 100-mL three-necked flask containing 20 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 in a dropping funnel over 3 hours. The start of dropwise addition was defined 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 solution was water-cooled and cooled to 30 캜 or lower. The cooled polymerization solution was poured into 400 g of methanol, and the precipitated white powder was separated by filtration. The white powder obtained by filtration was washed twice with 80 g of methanol, followed by filtration and drying at 50 ° C for 17 hours to synthesize (14.8 g, yield 74%) as a white powdery polymer (E-1). The polymer (E-1) had an Mw of 7,300 and an Mw / Mn of 1.53. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit derived from (M'-1) and (M'-20) was 60.3 mol% and 39.7 mol%, respectively.

[Examples 69 to 206] (Production of polymers (A1-1) to (A1-138)

Polymers (A1-1) to (A1-138) used as a base polymer were synthesized in the same manner as in Synthesis Example 1, except that monomers having the types and amounts shown in Tables 1 to 7 were used. In the tables, &quot; - &quot; indicates that the corresponding monomers are not used.

&Lt; Preparation of water repellent polymer additive ([A] polymer and [D] polymer)

[Synthesis Example 2] (Production of polymer (D-1)

79.9 g (70 mol%) of the compound (M'-2) and 20.91 g (30 mol%) of the compound (M'-27) were dissolved in 100 g of 2-butanone and dimethyl 2,2'-azobis 4.77 g of isobutyrate was 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 added dropwise over 3 hours with a dropping funnel. The start of dropwise addition was defined 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 solution was water-cooled and cooled to 30 캜 or lower. The reaction solution was transferred to a 2 L separatory funnel, and then the polymerization solution was uniformly diluted with 150 g of n-hexane, and 600 g of methanol was added thereto. Subsequently, 30 g of distilled water was added, and the mixture was further stirred and allowed to stand for 30 minutes. Thereafter, the lower layer was recovered to obtain a propylene glycol monomethyl ether acetate solution (yield: 60%) containing the solid polymer (D-1). The polymer (D-1) had an Mw of 7,200 and an Mw / Mn of 2.00. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit derived from (M'-2) and (M'-27) was 71.1 mol% and 28.9 mol%, respectively.

[Examples 207 to 215] (Preparation of polymers (A2-1) to (A2-9)

Polymers (A2-1) to (A2-9) used as water repellent polymer additives were synthesized in the same manner as in Synthesis Example 2, except that the monomers having the kinds and amounts shown in Table 8 were used. In the tables, &quot; - &quot; indicates that the corresponding monomers are not used.

&Lt; Preparation of radiation-sensitive resin composition >

The respective components used in the preparation of the radiation sensitive resin composition are shown below.

[[B] Radiation-sensitive acid generator [

(B-1) to (B-4).

[[C] acid diffusion control agent]

A compound represented by the following formulas (C-1) to (C-5).

[[F] Solvent]

F-1: Propylene glycol monomethyl ether acetate

F-2: Cyclohexanone

[[G] Sedimentation accelerator]

G-1:? -Butyrolactone

[Example 216]

100 parts by mass of the polymer (A-1) as the base polymer, 8.5 parts by mass of the (B-1) as the radiation-sensitive acid generator, (C-1) 2.3 as the acid diffusion controller 3 parts by mass of (D-1) as the [D] polymer, 2,240 parts by mass of (F-1) as the [F] solvent and 960 parts by mass of (F- 1) were mixed to prepare a radiation-sensitive resin composition (J-1).

[Examples 217 to 472 and Comparative Examples 1 and 2]

(J-2) to (J-257), (CJ-1) and (CJ-2) were obtained in the same manner as in Example 1, except that the components shown in Tables 9 to 20 were used. ). In addition, &quot; - &quot; in each table indicates that the corresponding component is not used.

&Lt; Formation of resist pattern (1) >

("ARC66" manufactured by Brewers Science) was applied to the surface of a 12-inch silicon wafer using a spin coater ("Clean Track ACT12" manufactured by Tokyo Electron Co., Ltd.) For 60 seconds to form a lower antireflection film having a film thickness of 105 nm. Each of the radiation sensitive resin compositions (J-1 to 96, J-186 to 257 and CJ-1) described in Tables 9 to 13 and Tables 18 to 20 prepared above was coated on this lower layer antireflection film using the above- And PB was carried out at 90 캜 for 60 seconds. Thereafter, the substrate was cooled at 23 DEG C for 30 seconds to form a resist film having a thickness of 90 nm. Subsequently, this resist film was exposed to 40 nm line-and-space (1L1S (nm)) under optical conditions of NA = 1.3 and dipole (Sigma 0.977 / 0.782) using an ArF excimer laser immersion lithography apparatus ("NSR-S610C" ) Was exposed through a mask pattern. After exposure, PEB was performed at 90 캜 for 60 seconds. Thereafter, alkali development was performed using a 2.38% by mass aqueous solution of TMAH as an alkali developing solution, followed by washing with water and drying to form a positive resist pattern. At the time of forming the resist pattern, the exposure amount formed by the line width formed by the 1: 1 line and space mask having the target dimension of 40 nm and the line width of 40 nm formed by the 1: 1 line and space was defined as the optimum exposure amount.

&Lt; Formation of resist pattern (2) >

A negative resist pattern was formed in the same manner as in the formation of the resist pattern (1) except that the organic solvent was developed using n-butyl acetate instead of the TMAH aqueous solution and the cleaning with water was not performed.

&Lt; Formation of resist pattern (3) >

(J-97 to 185 and CJ-2) shown in Tables 14 to 17 were applied to a surface of an 8-inch silicon wafer using a spin coater ("Clean Track ACT8" manufactured by Tokyo Electron Co., Ltd.) Lt; 0 &gt; C for 60 seconds. Thereafter, the substrate was cooled at 23 DEG C for 30 seconds to form a resist film having a thickness of 50 nm. Subsequently, the resist film was irradiated with an electron beam using a simple electron beam drawing apparatus (&quot; HL800D &quot;, output: 50 KeV, current density: 5.0 A / cm 2, manufactured by Hitachi Seisakusho Co., Ltd.). After the irradiation, PEB was performed at 120 캜 for 60 seconds. Thereafter, the resist film was developed with an aqueous solution of 2.38% by mass of TMAH as an alkali developing solution at 23 占 폚 for 30 seconds, washed with water, and dried to form a positive resist pattern.

<Evaluation>

The resist pattern thus formed was measured according to the following method to evaluate each radiation sensitive resin composition. A scanning electron microscope (&quot; CG-4100 &quot; manufactured by Hitachi High-Technologies Corporation) was used for measurement of the resist pattern. &Quot; - &quot; in each table indicates that it is a criterion of evaluation. Further, Examples 216 to 311 and Examples 401 to 472 were compared with Comparative Example 1. Examples 312 to 400 were compared with Comparative Example 2.

[LWR performance]

The resist pattern was observed from above the pattern using the scanning electron microscope. A total of 50 line-widths were measured at an arbitrary point, and 3 sigma values were obtained from the distribution of the measured values, and this was regarded as the LWR performance. The LWR performance shows that the smaller the value, the better. When the value of the LWR performance is compared with the value of the comparative example (judgment criterion), when the improvement of 10% or more (the value of the LWR performance is 90% or less) is observed, the LWR performance is said to be "good" And the value of the LWR performance is more than 90%).

[CD uniformity (CDU performance)]

The formed resist pattern was observed from above the pattern using the scanning electron microscope. A line width was measured at 20 points in a range of 400 nm, and the average value thereof was measured at a total of 500 points at arbitrary points. A 3 sigma value was obtained from the distribution of the measured values, and this was regarded as CD uniformity (nm). The smaller the CD uniformity is, the better the fluctuation of the line width in the long period is small. When the value of the CD uniformity is compared with the value of the comparative example (judgment criterion), when the improvement of 10% or more (the value of the CD uniformity is 90% or less) is seen, the CD uniformity is referred to as "good" And the value of the CD uniformity is more than 90%).

[Resolution]

The minimum dimension of the resist pattern to be resolved at the optimum exposure amount was measured, and the result of the measurement was made to be a resolution. The smaller the measured value, the better the resolution. When the obtained measured value is compared with the measured value (judgment reference) of the comparative example, when the improvement of 10% or more (the minimum resist pattern dimension is 90% or less) is observed, the resolution is referred to as "good" And the resist pattern dimension was more than 90%), it was evaluated as &quot; defective &quot;.

[Cross-sectional shape]

Sectional shape of the resist pattern to be resolved at the optimum exposure amount was observed to measure the line width Lb at the center of the resist pattern and the line width La at the top of the resist pattern. At this time, in the case of 0.9? La / Lb? 1.1, the cross-sectional shape was "good", and when it was outside the above range, it was evaluated as "poor".

[Focal depth]

In the resist pattern resolved at the optimal exposure amount, the dimension when the focus is changed in the depth direction is observed, and the margin in the depth direction in which the pattern dimension falls within the range of 90% to 110% And the measured value was set as the depth of focus. The larger the measured value, the better the depth of focus. When the obtained measurement value is compared with the measurement value (judgment standard) of the comparative example, when the improvement of 10% or more (the depth of focus of 110% or more) is seen, the depth of focus is called "good" and an improvement of less than 10% Is less than 110%), it was evaluated as &quot; defective &quot;.

[Exposure margin (EL performance)]

The ratio of the exposure amount range when the resolution of the mask pattern for forming a resist pattern of 40 nm line and space (1L / 1S) is within ± 10% of the design dimension of the mask is set to And the exposure margin (EL performance) (%). The larger the exposure margin is, the smaller the amount of change in the patterning performance with respect to the change in exposure amount is. When the value of the exposure margin is 10% or more (the value of the exposure margin is 110% or more) when the value of the exposure margin is compared with the value (judgment standard) of the comparative example, the exposure margin is referred to as "good" (The value of the exposure margin was less than 110%), it was evaluated as &quot; poor &quot;.

[MEEF performance]

Using the scanning electron microscope, five kinds of mask sizes (48.0 nmLine / 100 nmPitch, 49.0 nmLine / 100 nmPitch, 50.0 nmLine / 100 nmPitch, 51.0 nmLine / 100 nm Pitch, 52.0 nm Line / 100 nm pitch). The measured values obtained by using the mask size and the vertical axis as the line widths formed by the respective mask sizes are plotted on the abscissa and the slope of the approximated straight line calculated by the least squares method. The MEEF performance shows that the closer the value is to 1, the better. MEEF performance is referred to as &quot; good &quot; when an improvement of 10% or more (MEEF performance value of 90% or less) is seen when the MEEF performance value is compared with the value of the comparative example (judgment standard) MEEF performance value is more than 90%), it was evaluated as &quot; poor &quot;.

As is clear from the results of Tables 21 to 32, the radiation sensitive resin composition of the Example exhibits low LWR performance and CD uniformity, suppresses the upper loss, has high resolution, It is possible to form a resist pattern hardly deteriorated in depth and exhibiting excellent MEEF performance. On the contrary, the performance of the radiation sensitive resin composition of the comparative example was insufficient.

The radiation sensitive resin composition of the present invention and the method of forming a resist pattern exhibit excellent LWR performance, CD uniformity and rectangularity of sectional shape while exhibiting excellent exposure margin, depth of focus and MEEF performance, A resist pattern can be formed. The polymer of the present invention can be suitably used as a polymer component of the radiation-sensitive resin composition. The compound of the present invention can be suitably used as a monomer of the polymer. According to the method for producing a compound of the present invention, the above compound can be produced easily and at a good yield. Therefore, they can be suitably used for manufacturing semiconductor devices, which are expected to be further miniaturized thereafter.

Claims (10)

A polymer having a structural unit (I) represented by the following formula (1), and
Radiation-sensitive acid generator
By weight of the radiation-sensitive resin composition.

(1), R ¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R ² is a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic group containing a polar group, R ² and R ³ may combine with each other to form an alicyclic structure having 3 to 20 ring members including a polar group, which is constituted together with carbon atoms to which they are bonded, R ⁴ is a monovalent organic group, and X and Y is independently a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, provided that at least one of X and Y is a divalent straight chain A hydrocarbon group or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, and R ² or X and R ¹ may be combined with each other to form a ring structure having a reduced number of 5 to 20, The radiation sensitive resin composition according to claim 1, wherein the polymer further comprises a structural unit (II) represented by the following formula (2) or (3).

(2), R ⁵ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R ⁶ is a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms , R ⁷ and R ⁸ are each independently a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms or may be a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, Represents an alicyclic structure having 3 to 20 carbon atoms,
In formula (3), R ⁹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, p is 0 or 1, with the proviso that some or all of the hydrogen atoms of the cycloalkenyl group may be substituted with hydrocarbon groups, The carbon atom of the cycloalkenyl group may be bridged with a hydrocarbon chain) The positive resist composition according to claim 1 or 2, wherein the polymer is a structural unit other than the structural unit (I) and contains a structural unit (III) containing a lactone structure, a cyclic carbonate structure, a sultone structure, a hydroxyl group or an oxo group By weight of the radiation-sensitive resin composition. 3. The radiation-sensitive resin composition according to claim 1 or 2, wherein the radiation-sensitive acid generator is a compound represented by the following formula (4).

(In the formula (4), R ¹⁰ is a monovalent group containing an alicyclic structure having 6 or more alicyclic rings or a monovalent group containing an aliphatic heterocyclic structure having 6 or more alicyclic rings, R ¹¹ is a fluorinated alkanediyl group having 1 to 10 carbon atoms And X &lt; ⁺ & gt ^; is a monovalent radiation-decomposable onium cation) A step of forming a resist film,
A step of exposing the resist film, and
A step of developing the exposed resist film
The resist pattern forming method comprising:
Wherein the resist film is formed from the radiation-sensitive resin composition according to any one of claims 1 to 3. A resist pattern forming method comprising: A polymer having a structural unit (I) represented by the following formula (1).

(1), R ¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R ² is a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic group containing a polar group, R ² and R ³ may combine with each other to form an alicyclic structure having a reducing number of 3 to 20, which is constituted together with the carbon atom to which they are bonded, and R ⁴ is a monovalent organic group; X and Y are each independently , A bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, provided that at least one of X and Y is a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a divalent straight chain hydrocarbon group having 3 to 12 carbon atoms And R &lt; ² &gt; or X and R &lt; ¹ &gt; are taken together with the atomic group to which they are bonded to form a ring structure having a reduced number of 5 to 20) A compound represented by the following formula (5).

(5), R ¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R ² is a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic group containing a polar group, R ² and R ³ may combine with each other to form an alicyclic structure having a reducing number of 3 to 20, which is constituted together with the carbon atom to which they are bonded, and R ⁴ is a monovalent organic group; X and Y are each independently , A bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, provided that at least either of X and Y is a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a divalent straight chain hydrocarbon group having 3 to 12 carbon atoms And R &lt; ² &gt; or X and R &lt; ¹ &gt; are taken together with the atomic group to which they are bonded to form a ring structure having a reduced number of 5 to 20) A process for producing a compound represented by the following formula (5a), which comprises the step of reacting a compound represented by the following formula (a) with a compound represented by the following formula (b)

(Formula (a), (b) and (5a) of, R ^1A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R ^2A is a hydrogen atom or a monovalent organic group, R ³ contains a polar group , Provided that R ^2A and R ³ may combine with each other to form an alicyclic structure having 3 to 20 carbon atoms, which is composed of a polar group, and R ⁴ is a monovalent organic group , X ^A and Y are each independently a single bond, a bivalent straight chain hydrocarbon group having 1 to 12 carbon atoms, or a bivalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, provided that at least one of X ^A and Y is a straight- Z is a halogen atom, a hydroxy group, or -OCOR ', and R' is a monovalent hydrocarbon group having 1 to 30 carbon atoms), a divalent acyclic hydrocarbon group having 1 to 12 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, A process for producing a compound represented by the following formula (5b), which comprises the step of reacting a compound represented by the formula (e) and a compound represented by the formula (f) in the presence of zinc metal.

(Wherein R ^2A is a hydrogen atom or a monovalent organic group and R ³ is a monovalent organic group containing a polar group, provided that R ^{2 A} and R ³ are combined with each other, And R ⁴ is a monovalent organic group and Y is a divalent straight chain hydrocarbon group having 1 to 12 carbon atoms or a linear or branched alkylene group having 3 to 20 carbon atoms, And R ^X and R ^Y each independently represent a hydrogen atom or a monovalent straight chain hydrocarbon group having 1 to 10 carbon atoms, or may be bonded together with a carbon atom or a carbon chain to which they are bonded to form a bivalent alicyclic hydrocarbon group A is an integer of 1 to 4, and when a is 2 or more, plural R ^x may be the same or different, and plural R ^y may be the same or different from each other And may be different , R ^Z is a group having 1 to 10 monovalent chain hydrocarbon group or a monovalent alicyclic having 3 to 10 hydrocarbon group, T is a halogen atom, A is a monovalent oxyhydrocarbon of a halogen atom, a hydroxyl group, having 1 to 20 carbon atoms Group or -OCOR ^T and R ^T is a monovalent hydrocarbon group of 1 to 20 carbon atoms) A process for producing a compound represented by the following formula (5c), which comprises the step of reacting a compound represented by the formula (g) and a compound represented by the formula (f) in the presence of zinc metal.

(In the formulas (g), (f) and (5c), R ³ is a monovalent organic group containing a polar group, R ⁴ is a monovalent organic group and Y is a single bond, a divalent straight- A hydrocarbon group or a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms; R ^V and R ^W each independently represent a hydrogen atom, a halogen atom, a hydroxy group or a monovalent organic group having 1 to 10 carbon atoms, A is an integer of 1 to 4, and when a is 2 or more, a plurality of R ^v may be the same or different from each other and, a plurality of R ^W is and may be the same or different, T is a halogen atom, a is a monovalent oxyhydrocarbon of a halogen atom, a hydroxyl group, having 1 to 20 carbon atoms or -OCOR ^T, R ^T is a C1 To 20 monovalent hydrocarbon groups)