JP2017203885A - Radiation-sensitive resin composition, resist pattern forming method, method for producing acid diffusion controller, and method for producing radiation-sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition that can effectively reduce defects.SOLUTION: A radiation-sensitive resin composition contains a polymer having an acid dissociable group, a compound having an anion represented by formula (1), and a solvent. X is selected from -C(=O) Y, -C(=O) OY, -C(=O) NYY', -S(=O)Y, -S(=O)OY, -S(=O)NYY', -C(=O) OC(=O) Y, and -C(=O) N(Y) C(=O) Y'. R, R, R, R, Y and Y' are a hydrogen atom or a C1-C20 monovalent organic group, or a 3-20 membered ring structure in which Y or Y' and R, Y or Y' and R, Y or Y' and R, or Y or Y' and Rbind to each other. Rand Rare a fluorine atom or a C1-C4 monovalent fluorinated hydrocarbon group.SELECTED DRAWING: None

Description

  The present invention relates to a radiation sensitive resin composition, a resist pattern forming method, a method for producing an acid diffusion controller, and a method for producing a radiation sensitive resin composition.

  A chemically amplified radiation-sensitive resin composition used for microfabrication by lithography generates an acid at an exposed portion by irradiation with far-ultraviolet rays such as ArF excimer laser light, charged particle beams such as electron beams, and the like. A resist pattern is formed by causing a difference in dissolution rate in the developer between the exposed portion and the unexposed portion by a chemical reaction using a catalyst.

  In the formation of such a resist pattern, an immersion exposure method is suitably used as a method for forming a finer resist pattern. In this method, the exposure lens and the resist film are filled with an immersion medium having a higher refractive index than air or an inert gas for exposure. According to this immersion exposure method, there is an advantage that even when the numerical aperture of the lens is increased, the depth of focus is hardly lowered and high resolution is obtained.

  The radiation-sensitive resin composition used in such an immersion exposure method is to suppress elution of a radiation-sensitive acid generator from the resist film to the immersion medium, and to improve the drainage of the resist film. As a purpose, one containing a fluorine atom-containing polymer having high water repellency has been proposed (see International Publication No. 2007/116664).

International Publication No. 2007/116664

  However, since the fluorine atom-containing polymer has high water repellency, it may cause development defects such as blob defects due to adhesion of development residues not only in the immersion exposure method but also in EUV exposure. In the immersion exposure method, the occurrence of watermark defects that leave droplet marks on the resist pattern due to the presence of water (immersion medium) remaining on the protective film during immersion exposure is suppressed. It is also sought to do. However, the above conventional radiation-sensitive resin composition cannot satisfy these requirements.

  The present invention has been made based on the above circumstances, the purpose of which is a radiation sensitive resin composition excellent in development defect suppression and watermark defect suppression, a resist pattern forming method using the same, It is providing the manufacturing method of an acid diffusion control agent, and the manufacturing method of a radiation sensitive resin composition.

（式（１）中、Ｘは、−Ｃ（＝Ｏ）Ｙ、−Ｃ（＝Ｏ）ＯＹ、−Ｃ（ＧＲ^Ｘ）_２Ｙ、−Ｃ（＝Ｏ）ＮＹＹ’、−Ｓ（＝Ｏ）_２Ｙ、−Ｓ（＝Ｏ）_２ＯＹ、−Ｓ（＝Ｏ）_２ＮＹＹ’、−Ｃ（＝Ｏ）ＯＣ（＝Ｏ）Ｙ又は−Ｃ（＝Ｏ）Ｎ（Ｙ）Ｃ（＝Ｏ）Ｙ’である。Ｇは、それぞれ独立して酸素原子又は硫黄原子である。Ｒ^Ｘは、それぞれ独立して、炭素数１〜２０の１価の有機基であるか、又は２つのＲ^ｘが互いに合わせられこれらが結合する−Ｇ−Ｃ−Ｇ−と共に環員数４〜２０の環構造を構成する。Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｙ及びＹ’は、それぞれ独立して、水素原子若しくは炭素数１〜２０の１価の有機基であるか、又はＹ若しくはＹ’とＲ^１、Ｙ若しくはＹ’とＲ^２、Ｙ若しくはＹ’とＲ^３又はＹ若しくはＹ’とＲ^４が、互いに合わせられこれらが結合する炭素原子と共に構成される環員数３〜２０の環構造を構成する。但し、Ｒ^１乃至Ｒ^４が１価の有機基である場合、Ｒ^１乃至Ｒ^４はフッ素原子を含まない。Ｒ^ｆ１及びＲ^ｆ２は、それぞれ独立して、フッ素原子又は炭素数１〜４の１価のフッ素化炭化水素基である。） The invention made in order to solve the above-mentioned problems is a radiation-sensitive resin comprising a first polymer having an acid-dissociable group, a first compound having an anion represented by the following formula (1), and a solvent. It is a composition.

(In formula (1), X, -C (= O) Y, -C (= O) OY, -C (GR X) 2 Y, -C (= O) NYY ', - S (= O) ₂ Y, —S (═O) ₂ OY, —S (═O) ₂ NYY ′, —C (═O) OC (═O) Y or —C (═O) N (Y) C (═O) Y ′, G is each independently an oxygen atom or a sulfur atom, R ^X is each independently a monovalent organic group having 1 to 20 carbon atoms, or two R ^x are Together with -G-C-G-, which are combined with each other, form a ring structure having 4 to 20 ring members, R ¹ , R ² , R ³ , R ⁴ , Y and Y ′ are each independently A hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, or Y or Y ′ and R ¹ , Y or Y ′ and R ² , Y or Y ′ and R ^3, or Y or Y ′ and R ⁴ Are To form a ring structure having 3 to 20 ring members together with the carbon atom to which they are bonded, provided that when R ^{1 to} R ⁴ are monovalent organic groups, R ^{1 to} R ⁴ are fluorine atoms. R ^f1 and R ^f2 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 4 carbon atoms.)

  Another invention made to solve the above problems includes a step of coating the radiation-sensitive resin composition on one side of the substrate, and a step of exposing the resist film obtained by the coating step. And a step of developing the exposed resist film.

（式（ａ）〜（ｅ）及び（１’）中、Ｘは、−Ｃ（＝Ｏ）Ｙ、−Ｃ（＝Ｏ）ＯＹ、−Ｃ（ＧＲ^Ｘ）_２Ｙ、−Ｃ（＝Ｏ）ＮＹＹ’、−Ｓ（＝Ｏ）_２Ｙ、−Ｓ（＝Ｏ）_２ＯＹ、−Ｓ（＝Ｏ）_２ＮＹＹ’、−Ｃ（＝Ｏ）ＯＣ（＝Ｏ）Ｙ又は−Ｃ（＝Ｏ）Ｎ（Ｙ）Ｃ（＝Ｏ）Ｙ’である。Ｇは、それぞれ独立して酸素原子又は硫黄原子である。Ｒ^Ｘは、それぞれ独立して、炭素数１〜２０の１価の有機基であるか、又は２つのＲ^ｘが互いに合わせられこれらが結合する−Ｇ−Ｃ−Ｇ−と共に環員数４〜２０の環構造を構成する。Ｒ^１’、Ｒ^３’、Ｒ^４’、Ｙ及びＹ’は、それぞれ独立して、水素原子若しくは炭素数１〜２０の１価の有機基であるか、又はＹ若しくはＹ’とＲ^１’、Ｙ若しくはＹ’とＲ^３’又はＹ若しくはＹ’とＲ^４’が、互いに合わせられこれらが結合する炭素原子と共に構成される環員数３〜２０の環構造を構成する。但し、Ｒ^１’、Ｒ^３’及び、Ｒ^４’が１価の有機基である場合、Ｒ^１’、Ｒ^３’及び、Ｒ^４’はフッ素原子を含まない。Ｒ^６は、炭素数１〜２０の１価の炭化水素基である。Ｒ^ｆ１及びＲ^ｆ２は、それぞれ独立して、フッ素原子又は炭素数１〜４の１価のフッ素化炭化水素基である。Ｑは、塩素原子、臭素原子又はヨウ素原子である。Ｚ^＋は、１価のカチオンである。Ｍ^―は、１価のアニオンである。） Yet another invention made to solve the above problems is a method for producing an acid diffusion controller used in a radiation-sensitive resin composition, wherein the compound represented by the following formula (a) and the following formula (b) In the following formula (d), the step of obtaining the compound represented by the following formula (c) by the reaction with the compound represented by formula (c) and the hydrolysis of the ester group of the compound represented by the following formula (c) A step of obtaining a compound represented by the following formula (1 ′) by a reaction of a compound represented by the following formula (d) with a salt represented by the following formula (e): It is a manufacturing method of an acid diffusion control agent provided with this.

(In the formulas (a) to (e) and (1 ′), X represents —C (═O) Y, —C (═O) OY, —C (GR ^X ) ₂ Y, —C (═O). NYY ′, —S (═O) ₂ Y, —S (═O) ₂ OY, —S (═O) ₂ NYY ′, —C (═O) OC (═O) Y or —C (═O) N (Y) C (═O) Y ′, G is each independently an oxygen atom or a sulfur atom, and R ^X is each independently a monovalent organic group having 1 to 20 carbon atoms. Or two R ^x are combined with each other to form a ring structure having 4 to 20 ring members together with —G—C—G—, in which R ¹ ′, R ³ ′, R ⁴ ′, Y and Y ′ is independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, or Y or Y ′ and R ¹ ′, Y or Y ′ and R ³ ′, or Y or Y ′. and ^{R 4} 'is, together with each other Which constitutes the ring structure formed ring members 3 to 20 together with the carbon atoms to which they are attached. However, R ^{1 ',} R 3' and, R 4 ^'when it is a monovalent organic group, R ^1' , R ³ ′ and R ⁴ ′ do not contain a fluorine atom, R ⁶ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ^f1 and R ^f2 are each independently a fluorine atom or A monovalent fluorinated hydrocarbon group having 1 to 4 carbon atoms, Q is a chlorine atom, a bromine atom or an iodine atom, Z ⁺ is a monovalent cation, M ⁻ is a monovalent anion. .)

（式（１）中、Ｘは、−Ｃ（＝Ｏ）Ｙ、−Ｃ（＝Ｏ）ＯＹ、−Ｃ（ＧＲ^Ｘ）_２Ｙ、−Ｃ（＝Ｏ）ＮＹＹ’、−Ｓ（＝Ｏ）_２Ｙ、−Ｓ（＝Ｏ）_２ＯＹ、−Ｓ（＝Ｏ）_２ＮＹＹ’、−Ｃ（＝Ｏ）ＯＣ（＝Ｏ）Ｙ又は−Ｃ（＝Ｏ）Ｎ（Ｙ）Ｃ（＝Ｏ）Ｙ’である。Ｇは、それぞれ独立して酸素原子又は硫黄原子である。Ｒ^Ｘは、それぞれ独立して、炭素数１〜２０の１価の有機基であるか、又は２つのＲ^ｘが互いに合わせられこれらが結合する−Ｇ−Ｃ−Ｇ−と共に環員数４〜２０の環構造を構成する。Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｙ及びＹ’は、それぞれ独立して、水素原子若しくは炭素数１〜２０の１価の有機基であるか、又はＹ若しくはＹ’とＲ^１、Ｙ若しくはＹ’とＲ^２、Ｙ若しくはＹ’とＲ^３又はＹ若しくはＹ’とＲ^４が、互いに合わせられこれらが結合する炭素原子と共に構成される環員数３〜２０の環構造を構成する。但し、Ｒ^１乃至Ｒ^４が１価の有機基である場合、Ｒ^１乃至Ｒ^４はフッ素原子を含まない。Ｒ^ｆ１及びＲ^ｆ２は、それぞれ独立して、フッ素原子又は炭素数１〜４の１価のフッ素化炭化水素基である。） Still another invention made in order to solve the above-mentioned problems is a radiation sensitive method comprising a step of mixing a first polymer having an acid dissociable group, a compound represented by the following formula (1), and a solvent. It is a manufacturing method of a resin composition.

(In formula (1), X, -C (= O) Y, -C (= O) OY, -C (GR X) 2 Y, -C (= O) NYY ', - S (= O) ₂ Y, —S (═O) ₂ OY, —S (═O) ₂ NYY ′, —C (═O) OC (═O) Y or —C (═O) N (Y) C (═O) Y ′, G is each independently an oxygen atom or a sulfur atom, R ^X is each independently a monovalent organic group having 1 to 20 carbon atoms, or two R ^x are Together with -G-C-G-, which are combined with each other, form a ring structure having 4 to 20 ring members, R ¹ , R ² , R ³ , R ⁴ , Y and Y ′ are each independently A hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, or Y or Y ′ and R ¹ , Y or Y ′ and R ² , Y or Y ′ and R ^3, or Y or Y ′ and R ⁴ Are To form a ring structure having 3 to 20 ring members together with the carbon atom to which they are bonded, provided that when R ^{1 to} R ⁴ are monovalent organic groups, R ^{1 to} R ⁴ are fluorine atoms. R ^f1 and R ^f2 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 4 carbon atoms.)

  Here, the “organic group” refers to a group containing at least one carbon atom. The “acid-dissociable group” refers to a group that replaces a hydrogen atom such as a carboxy group or a hydroxy group and dissociates by the action of an acid. The “number of ring members” refers to the number of atoms constituting the ring in the alicyclic structure, aromatic ring structure, aliphatic heterocyclic structure or aromatic heterocyclic structure.

  The radiation-sensitive resin composition and the resist pattern forming method of the present invention can be suitably used for pattern formation in semiconductor device production or the like where further miniaturization is expected.

<Radiation sensitive resin composition>
The radiation-sensitive resin composition contains a [A] polymer, a [B] compound, and a [C] solvent. The radiation-sensitive resin composition contains, as a suitable component, an [E] polymer having a mass content of fluorine atoms larger than that of the [D] compound and [A] polymer that generate sulfonic acid by the action of radiation. It may be. Furthermore, the said radiation sensitive resin composition may contain the other arbitrary component in the range which does not impair the effect of this invention. Since the radiation-sensitive resin composition has the above-described configuration, it is excellent in development defect suppression, watermark defect suppression, and storage stability. Hereinafter, each component will be described.

<[A] polymer>
[A] The polymer is a polymer having the structural unit (I). According to the said radiation sensitive resin composition, the acid dissociable group of the [A] polymer of an exposed part dissociates with the acid which arises from a [B] compound etc. by irradiation of a radiation, and an exposed part and an unexposed part A difference occurs in solubility in the developer, and as a result, a resist pattern can be formed. [A] The polymer is usually a base polymer in the radiation-sensitive resin composition. The “base polymer” refers to a polymer having the largest content of the polymers constituting the resist pattern, and preferably occupies 50% by mass or more, more preferably 60% by mass or more.

  [A] In addition to the structural unit (I), the polymer is a structural unit containing a lactone structure, a cyclic carbonate structure, a sultone structure or a combination thereof (hereinafter also referred to as “structural unit (II)”), a phenolic hydroxyl group And / or a structural unit containing an alcoholic hydroxyl group (hereinafter also referred to as “structural unit (IV)”). Other structural units other than I) to (IV) may be included. [A] The polymer may have one or more of these structural units.

[Structural unit (I)]
The structural unit (I) is a structural unit containing an acid dissociable group. Examples of the structural unit (I) include a structural unit represented by the following formula (3) (hereinafter also referred to as “structural unit (I)”). [A] The polymer may have one or more structural units (I). Hereinafter, the structural unit (I) will be described.

In said formula (3), R ^<A1> is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ^A2 is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^A3 and R ^A4 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, a hydrogen atom, or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, or these groups are It represents a ring structure having 3 to 20 ring members that is formed together with the carbon atoms to which they are bonded.

  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 “chain hydrocarbon group” refers to a hydrocarbon group that does not include a cyclic structure but includes only a chain structure, and includes both a linear hydrocarbon group and a branched hydrocarbon group. The term “alicyclic hydrocarbon group” refers to a hydrocarbon group that includes only an alicyclic structure as a ring structure and does not include an aromatic ring structure, and includes a monocyclic alicyclic hydrocarbon group and a polycyclic alicyclic group. Includes both hydrocarbon groups. However, it is not necessary to be composed only of the alicyclic structure, and a part thereof may include a chain structure. “Aromatic hydrocarbon group” refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic structure.

R ^A1 is preferably a hydrogen atom or a methyl group, more preferably a methyl group, from the viewpoint of copolymerization of the monomer that gives the structural unit (I).

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^A2 , R ^A3 and R ^A4 include, for example, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and 1 to 3 carbon atoms. Valent alicyclic hydrocarbon group, monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the like.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, and an i-propyl group;
An alkenyl group such as an ethenyl group, a propenyl group, a butenyl group;
Examples thereof include alkynyl groups such as ethynyl group, propynyl group, and butynyl group. Among these, an alkyl group is preferable, an alkyl group having 1 to 4 carbon atoms is more preferable, a methyl group, an ethyl group, and an i-propyl group are further preferable, and an ethyl group is particularly preferable.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include monovalent monocyclic alicyclic saturated hydrocarbon groups such as a cyclopentyl group and a cyclohexyl group;
Monovalent monocyclic alicyclic unsaturated hydrocarbon groups such as a cyclopentenyl group and a cyclohexenyl group;
Monovalent polycyclic alicyclic saturated hydrocarbon groups such as norbornyl group, adamantyl group, tricyclodecyl group, tetracyclododecane;
And monovalent polycyclic alicyclic unsaturated hydrocarbon groups such as a norbornenyl group and a tricyclodecenyl group. Among these, a monovalent monocyclic alicyclic saturated hydrocarbon group and a monovalent polycyclic saturated alicyclic hydrocarbon group are preferable, and a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group are more preferable.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as phenyl group, tolyl group, xylyl group, mesityl group, naphthyl group, methylnaphthyl group, anthryl group, and methylanthryl group;
Examples include aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, and anthrylmethyl group.

Examples of the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms represented by R ^A3 and R ^A4 include, for example, a terminal on the bond side of the monovalent hydrocarbon group exemplified as R ^A2 , R ^A3 and R ^A4. And a group having an oxygen atom bonded thereto.

Examples of the alicyclic structure having 3 to 20 carbon atoms constituted by R ^A3 and R ^A4 together with the carbon atom to which they are bonded include, for example, cyclopropane structure, cyclobutane structure, cyclopentane structure, cyclohexane structure, norbornane structure, adamantane Alicyclic structures such as structures;
Examples thereof include aliphatic heterocyclic structures such as an oxacyclopentane structure, a thiacyclopentane structure, and an azacyclopentane structure. Among these, an alicyclic structure is preferable and a cyclohexane structure is more preferable.

  As the structural unit (I), for example, structural units represented by the following formulas (3-1) to (3-6) (hereinafter also referred to as “structural units (I-1) to (I-6)”) and the like Is mentioned.

In the above formulas (3-1) to (3-5), R ^{A1 to} R ^A4 have the same meaning as the above formula (3).
In said formula (3-1), i is an integer of 1-4.
In said formula (3-3), j is an integer of 1-4.
In the above formula (3-6), R ^{A2 ′} , R ^{A3 ′} and R ^{A4 ′} are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms.

  As i and j, 1-3 are preferable and 1 and 2 are more preferable.

  As the structural unit (I), structural units (I-1) to (I-5) are preferable.

  Examples of the structural unit (I) include a structural unit represented by the following formula.

In the above formula, R ^A1 has the same ^meaning as the above formula (3).

  As the structural unit (I), a structural unit derived from 1-alkyl-monocyclic cycloalkane-1-yl (meth) acrylate, a structure derived from 2-alkyl-polycyclic cycloalkane-2-yl (meth) acrylate A structural unit derived from a unit and 2- (cycloalkane-yl) propan-2-yl (meth) acrylate, preferably a structural unit derived from 1-i-propylcyclopentan-1-yl (meth) acrylate, 1- Structural units derived from methylcyclohexane-1-yl (meth) acrylate, structural units derived from 2-ethyl-adamantan-2-yl (meth) acrylate, 2-ethyl-tetracyclododecan-2-yl (meth) acrylate A structural unit derived from 2- (adamantan-1-yl) propan-2-yl (meth) acrylate Structural units and 2- (cyclohexane-1-yl) propan-2-yl (meth) structural units derived from acrylate to come more preferable.

  As a minimum of the content rate of structural unit (I), 10 mol% is preferable with respect to all the structural units which comprise a [A] polymer, 20 mol% is more preferable, 30 mol% is further more preferable, 40 mol% % Is particularly preferred. As an upper limit of the said content rate, 80 mol% is preferable, 75 mol% is more preferable, 70 mol% is further more preferable, 60 mol% is especially preferable. By making the content rate of structural unit (I) into the said range, the LWR performance of the said radiation sensitive resin composition etc. can be improved further.

[Structural unit (II)]
The structural unit (II) is a structural unit including a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof. [A] In addition to the structural unit (I), the polymer can further adjust the solubility in the developer more appropriately by having the structural unit (II). As a result, the radiation-sensitive resin composition The LWR performance of the product can be further improved. Moreover, the adhesiveness of the resist pattern formed from the said radiation sensitive resin composition and a board | substrate can be improved.

  Examples of the structural unit (II) include a structural unit represented by the following formula.

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

  As the structural unit (II), a structural unit having a lactone structure, a structural unit having a cyclic carbonate structure, and a structural unit having a sultone structure are preferable. A structural unit derived from a lactone structure-containing (meth) acrylate, a cyclic carbonate structure-containing ( More preferred are structural units derived from (meth) acrylate and structural units derived from sultone structure-containing (meth) acrylate, derived from norbornanelactone-yl (meth) acrylate, derived from cyanonorbornanelactone-yl (meth) acrylate Structural units derived from norbornanelactone-yloxycarbonylmethyl (meth) acrylate, structural units derived from γ-butyrolactone-yl (meth) acrylate, ethylene carbonate-ylmethyl (meth) acrylate Structural units derived from preparative and norbornane sultone - yl (meth) structural units derived from acrylate are more preferred.

  [A] When the polymer has the structural unit (II), the lower limit of the content ratio of the structural unit (II) is preferably 10 mol%, preferably 20 mol% with respect to the total structural units in the polymer [A]. Is more preferable, 30 mol% is further more preferable, and 40 mol% is particularly preferable. As an upper limit of the said content rate, 80 mol% is preferable, 70 mol% is more preferable, 65 mol% is further more preferable, 60 mol% is especially preferable. By making the content rate of structural unit (II) into the said range, the [A] polymer can adjust the solubility to a developing solution more appropriately, As a result, LWR of the said radiation sensitive resin composition is obtained. The performance and the like can be further improved. In addition, the adhesion between the obtained resist pattern and the substrate can be further improved.

[Structural unit (III)]
The structural unit (III) is a structural unit containing a phenolic hydroxyl group. In the case of using KrF excimer laser light, EUV, electron beam, etc. as the radiation to be irradiated in the exposure process in the resist pattern forming method, the sensitivity is further enhanced by having the structural unit (III) in the polymer [A]. Can do.

  Examples of the structural unit (III) include a structural unit represented by the following formula (4) (hereinafter also referred to as “structural unit (III)”).

In the formula ^{(4), R 14} is a hydrogen atom or a methyl group. R ¹⁵ is a monovalent organic group having 1 to 20 carbon atoms. p is an integer of 0-3. When p is 2 or 3, the plurality of R ¹⁵ may be the same or different. q is an integer of 1 to 3. However, p + q is 5 or less.

R ¹⁴ is preferably a hydrogen atom from the viewpoint of the copolymerizability of the monomer giving the structural unit (III).

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹⁵ include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a carbon-carbon boundary of this hydrocarbon group, or a terminal on the bond side. And a group (g) containing a divalent heteroatom-containing group, a group obtained by substituting part or all of the hydrogen atoms of the hydrocarbon group and group (g) with a heteroatom-containing group, and the like.

As said C1-C20 monovalent hydrocarbon group, the group similar to the group ^quoted by said R ^<A2> , R ^<A3> and R ^<A4> is mentioned.

  Examples of the hetero atom contained in the hetero atom-containing group include halogen atoms such as chlorine atom, bromine atom and fluorine atom, oxygen atom, sulfur atom, nitrogen atom, silicon atom and phosphorus atom. Among these, an oxygen atom, a sulfur atom, a nitrogen atom and a fluorine atom are preferable.

Examples of the divalent heteroatom-containing group contained between the carbon-carbon or at the terminal on the bond side include -C (= O)-, -O-, -NR'-, -S-, -C (= S) —, a combination of these, and the like. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Incidentally, when these divalent heteroatom-containing group contains carbon atoms, the total number of carbon atoms R ¹⁵ has from 1 to 20. including those contained in these divalent heteroatom-containing group.

  Examples of the hetero atom-containing group that is substituted with part or all of the hydrogen atoms of the hydrocarbon group and the group (g) include an oxo group (═O), a thioxo group (═S), a hydroxy group, and a carboxy group. , A sulfanyl group (-SH), an amino group, a cyano group, a halogen atom and the like.

  As said p, the integer of 0-2 is preferable, 0 and 1 are more preferable, and 0 is further more preferable.

  As said q, 1 and 2 are preferable and 1 is more preferable.

  As the structural unit (III), for example, structural units represented by the following formulas (4-1) to (4-4) (hereinafter also referred to as “structural units (III-1) to (III-4)”) and the like Is mentioned.

In the above formulas (4-1) to (4-4), R ¹⁴ has the same meaning as the above formula (4).

  As the structural unit (III), the structural unit (III-1) and the structural unit (III-2) are preferable, and the structural unit (III-1) is more preferable.

  [A] When the polymer has the structural unit (III), the lower limit of the content ratio of the structural unit (III) is preferably 10 mol% with respect to all the structural units constituting the [A] polymer. More preferably, mol% is more preferable, 30 mol% is further more preferable, and 40 mol% is especially preferable. As an upper limit of the said content rate, 80 mol% is preferable, 70 mol% is more preferable, 65 mol% is further more preferable, 60 mol% is especially preferable. By making the content rate of structural unit (III) into the said range, the said radiation sensitive resin composition can further improve a sensitivity.

  The structural unit (III) is obtained by polymerizing a monomer in which the hydrogen atom of the —OH group of hydroxystyrene is substituted with an acetyl group or the like, and then hydrolyzing the obtained polymer in the presence of a base such as an amine. It can be formed by performing a reaction or the like.

[Structural unit (IV)]
The structural unit (IV) is a structural unit containing an alcoholic hydroxyl group. [A] By having the structural unit (IV), the polymer can adjust the solubility in the developer more appropriately. As a result, the LWR performance of the radiation-sensitive resin composition is further improved. Can be made. In addition, the adhesion of the resist pattern to the substrate can be further improved.

  Examples of the structural unit (IV) include a structural unit represented by the following formula.

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

  As the structural unit (IV), a structural unit containing a hydroxyadamantyl group is preferable, and a structural unit derived from 3-hydroxyadamantyl (meth) acrylate is more preferable.

  [A] When a polymer has a structural unit (IV), as a minimum of the content rate of a structural unit (IV), 10 mol% is preferable with respect to all the structural units which comprise a [A] polymer, 20 More preferably, mol% is more preferable, 30 mol% is further more preferable, and 40 mol% is especially preferable. As an upper limit of the said content rate, 80 mol% is preferable, 70 mol% is more preferable, 65 mol% is further more preferable, 60 mol% is especially preferable. By setting the content ratio of the structural unit (IV) within the above range, the [A] polymer can be further appropriately adjusted in solubility in the developer, and as a result, the LWR of the radiation-sensitive resin composition can be adjusted. The performance and the like can be further improved. In addition, the adhesion of the resist pattern to the substrate can be further enhanced.

[Other structural units]
[A] The polymer may have other structural units in addition to the structural units (I) to (IV). Examples of the other structural unit include a structural unit containing a ketonic carbonyl group, a cyano group, a carboxy group, a nitro group, an amino group or a combination thereof, and a non-dissociable monovalent alicyclic hydrocarbon group ( And structural units derived from (meth) acrylic acid esters. As an upper limit of the content rate of another structural unit, 20 mol% is preferable with respect to all the structural units which comprise a [A] polymer, and 10 mol% is more preferable.

  [A] The lower limit of the content of the polymer is preferably 70% by mass, more preferably 80% by mass, and still more preferably 85% by mass with respect to the total solid content of the radiation-sensitive resin composition. “Total solid content” refers to the sum of components other than the solvent [C] in the radiation-sensitive resin composition. The radiation sensitive resin composition may contain one or more [A] polymers.

<[A] Polymer Synthesis Method>
[A] The polymer can be synthesized, for example, by polymerizing monomers that give each structural unit in a suitable solvent using a radical polymerization initiator or the like.

Examples of the radical polymerization initiator include azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (3-cyclopropyl). Azo radical initiators such as propionitrile), 2,2′-azobis (3,4-dimethylvaleronitrile), dimethyl 2,2′-azobisisobutyrate;
And peroxide radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, and the like. Of these, AIBN and dimethyl 2,2′-azobisisobutyrate are preferred, and AIBN is more preferred. These radical polymerization initiators can be used alone or in combination of two or more.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane;
Cycloaliphatic saturated hydrocarbons such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane;
Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene;
Halogenated hydrocarbons such as chlorobutane, bromohexane, dichloroethane, hexamethylene dibromide, chlorobenzene;
Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate;
Ketones such as acetone, methyl ethyl ketone, 4-methyl-2-pentanone, 2-heptanone;
Ethers such as tetrahydrofuran, dimethoxyethanes, diethoxyethanes;
Examples include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol. The solvent used for these polymerizations may be used alone or in combination of two or more.

  As a minimum of reaction temperature in superposition | polymerization, 40 degreeC is preferable and 50 degreeC is more preferable. As an upper limit of the said reaction temperature, 150 degreeC is preferable and 120 degreeC is more preferable. As a minimum of reaction time in superposition | polymerization, 1 hour is preferable and 2 hours is more preferable. The upper limit of the reaction time is preferably 48 hours, more preferably 24 hours.

  [A] The lower limit of the weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer is preferably 1,000, more preferably 3,000, still more preferably 4,000, 000 is particularly preferred. The upper limit of Mw is preferably 50,000, more preferably 30,000, still more preferably 20,000, and particularly preferably 10,000. [A] By making Mw of a polymer into the said range, the applicability | paintability of the said radiation sensitive resin composition improves, and development defect inhibitory property improves more.

  [A] The lower limit of the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene (Mw / Mn) by gel permeation chromatography (GPC) of the polymer is usually 1 and preferably 1.1. As an upper limit of the ratio, 5 is preferable, 3 is more preferable, and 2 is more preferable.

<[B] Compound>
[B] The compound is a compound having an anion represented by the following formula (1). The compound [B] exerts an effect as an acid diffusion controlling agent that controls the diffusion phenomenon of the acid generated from the following compound [D] in the resist film by the action of radiation and suppresses an undesirable chemical reaction in the non-exposed region. The radiation-sensitive resin composition can be made excellent in development defect suppression, watermark defect suppression, and storage stability by using the [B] compound as an onium salt compound as an acid diffusion controller. . [B] A compound may be used independently and may use 2 or more types together.

The formula (1), X, -C (= O) Y, -C (= O) OY, -C (GR X) 2 Y, -C (= O) NYY ', - S (= O) ₂ Y, —S (═O) ₂ OY, —S (═O) ₂ NYY ′, —C (═O) OC (═O) Y or —C (═O) N (Y) C (═O) Y ′. G is each independently an oxygen atom or a sulfur atom. Each R ^X is independently a monovalent organic group having 1 to 20 carbon atoms, or two R ^x are combined with each other, and together with —G—C—G—, the number of ring members is 4 to 20 Of the ring structure. R ¹ , R ² , R ³ , R ⁴ , Y and Y ′ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, or Y or Y ′ and R ¹ , Y or Y ′ and R ² , Y or Y ′ and R ^3, or Y or Y ′ and R ⁴ are combined with each other to constitute a ring structure having 3 to 20 ring members constituted by the carbon atoms to which they are bonded. However, when R ^{1 to} R ⁴ are monovalent organic groups, R ^{1 to} R ⁴ do not contain a fluorine atom. R ^f1 and R ^f2 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 4 carbon atoms.

The said radiation sensitive resin composition is excellent in development defect inhibitory property and watermark defect inhibitory property by containing a [B] compound in addition to a [A] polymer and a [C] solvent. The reason why the radiation-sensitive resin composition has the above-described configuration and thus exhibits the above-mentioned effects is not necessarily clear, but can be inferred as follows, for example. That is, the anion of the [B] compounds, -COO ^- by two fluorine atoms bonded carbon atoms are attached, hydrophobicity of the entire radiation-sensitive resin composition by hydrophobic fluorine atom It is considered that the solubility in the developer can be improved by the electron withdrawing property while maintaining. As a result, it is thought that the development defect suppression property and watermark defect suppression property of the said radiation sensitive resin composition improve. Furthermore, when a conventional onium salt compound is contained as an acid diffusion control agent, precipitation of a hardly soluble salt due to a decomposition reaction with the following [E] polymer or the like is unavoidable, but according to the [B] compound, It is conceivable that the precipitation is suppressed due to the reasonably low nucleophilicity resulting from the structure of formula (1), and as a result, the storage stability of the radiation-sensitive resin composition is improved.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ^X of —C (GR ^X ) ₂ Y include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms and carbon of the hydrocarbon group. - group containing a divalent heteroatom containing group at the end of the bond side of the R ^X between atoms or between G-R ^X (g), a portion of the hydrogen atom of the hydrocarbon group and the group (g) is or Examples include groups in which all are substituted with heteroatom-containing groups.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and the number of carbon atoms. Examples thereof include 6-20 monovalent aromatic hydrocarbon groups.
Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, and t-butyl group;
An alkenyl group such as an ethenyl group, a propenyl group, a butenyl group;
Examples thereof include alkynyl groups such as ethynyl group, propynyl group, and butynyl group.

Examples of the alicyclic hydrocarbon group include monovalent monocyclic alicyclic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group;
A monovalent monocyclic alicyclic unsaturated hydrocarbon group such as a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group;
Monovalent polycyclic alicyclic saturated hydrocarbon group such as norbornyl group, adamantyl group, tricyclodecyl group, tetracyclododecyl group;
And monovalent polycyclic alicyclic unsaturated hydrocarbons such as a norbornenyl group, a tricyclodecenyl group, and a tetracyclododecenyl group.

Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and an anthryl group;
Examples thereof include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group and naphthylmethyl group.

  Examples of the hetero atom contained in the hetero atom-containing group include halogen atoms such as chlorine atom and bromine atom, oxygen atom, sulfur atom, nitrogen atom, silicon atom and phosphorus atom. Among these, an oxygen atom and a sulfur atom are preferable.

Examples of the divalent hetero atom-containing group contained in the end of the bond side of the R ^X between atoms or between G-R ^X, for example, -C (= O) - - the carbon of the hydrocarbon group, - O-, -S-, -C (= S)-, a group obtained by combining these, and the like. In addition, when these bivalent hetero atom containing groups contain a carbon atom, the total number of the carbon atoms which ^Rx has is 1-20 including what is contained in these divalent hetero atom containing groups.

  Examples of the hetero atom-containing group that is substituted with part or all of the hydrogen atoms of the hydrocarbon group and the group (g) include an oxo group (═O), a thioxo group (═S), a hydroxy group, and a carboxy group. , A sulfanyl group (-SH) and the like.

Examples of the ring structure having 4 to 20 ring members constituted with —G—C—G—, in which the two R ^x are combined with each other, include cyclic acetal rings such as 1,3-dioxacyclopentane ( A structure having a cyclic ketal ring), a structure having a ring containing a group represented by —O—C—S— such as 1-thia-3-oxacyclopentane, and the like, 1,3-dithiacyclopentane, etc. And a structure having a ring containing a group represented by —S—C—S—.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹ , R ² , R ³ , R ⁴ , Y and Y ′ include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, A group (g) containing a divalent heteroatom-containing group at the carbon-carbon end or bond-end side of the hydrocarbon group, and a part or all of the hydrogen atoms of the hydrocarbon group and group (g) are heteroatoms. And a group substituted with a containing group.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include the same groups as those described above for R ^X.

  Examples of the hetero atom contained in the hetero atom-containing group include halogen atoms such as chlorine atom and bromine atom, oxygen atom, sulfur atom, nitrogen atom, silicon atom and phosphorus atom. Among these, an oxygen atom, a sulfur atom and a nitrogen atom are preferable.

Examples of the divalent heteroatom-containing group contained between the carbon-carbon or at the terminal on the bond side include -C (= O)-, -O-, -NR'-, -S-, -C (= S) —, a combination of these, and the like. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. In addition, when these divalent hetero atom-containing groups contain carbon atoms, the total number of carbon atoms possessed by R ¹ , R ² , R ³ , R ⁴ , Y and Y ′ is the number of these divalent hetero atom-containing groups. It is 1-20 including what is contained.

  Examples of the hetero atom-containing group that is substituted with part or all of the hydrogen atoms of the hydrocarbon group and the group (g) include an oxo group (═O), a thioxo group (═S), a hydroxy group, and a carboxy group. , A sulfanyl group (-SH), an amino group, a cyano group, a halogen atom and the like.

Y or Y ′ and R ¹ , Y or Y ′ and R ² , Y or Y ′ and R ^3, or Y or Y ′ and R ⁴ are combined with each other, and the number of ring members is 3 to 20 composed of the carbon atoms to which they are bonded. Examples of the ring structure include alicyclic structures such as a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a norbornane structure, and an adamantane structure;
Examples thereof include aliphatic heterocyclic structures such as an oxacyclopentane structure, a thiacyclopentane structure, and an azacyclopentane structure.

  The ring structure may have any shape such as a single ring, a multi-ring, a condensed ring, and a bridged structure. The ring structure may have a substituent.

Y or Y ′ and R ¹ , Y or Y ′ and R ² , Y or Y ′ and R ^3, or Y or Y ′ and R ⁴ are combined with each other, and together with the carbon atom to which they are bonded, 3 to 20 carbon atoms Examples of the ring structure include a ring structure represented by the following formula.

  Among these, the ring structure is preferably a ring structure represented by the above formula (bb-1), a ring structure represented by the above formula (bb-5), or the like.

Examples of the monovalent fluorinated hydrocarbon group having 1 to 4 carbon atoms represented by R ^f1 and R ^f2 include a fluorinated alkyl group having 1 to 4 carbon atoms. The monovalent fluorinated hydrocarbon group having 1 to 4 carbon atoms represented by R ^f1 and R ^f2 is more preferably a perfluoroalkyl group, and more preferably a trifluoromethyl group.

As the X, from the viewpoint of enhancing the storage stability and developing defect suppression of the radiation-sensitive resin composition, -C (= O) Y, -C (= O) OY, -C (OR X) 2 _{Y, -S (= O) 2} Y, -S (= O) 2 OY, -S (= O) 2 NYY ', - C (= O) OC (= O) Y or -C (= O) N (Y) C (═O) Y ′ and R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, or Y or Y ′ and R ¹ , Y or Y ′ and R ² , Y or Y ′ and R ^3, or Y or Y ′ and R ⁴ represent an alicyclic structure or an aliphatic heterocyclic structure having 3 to 20 ring members configured together with the carbon atom to which they are bonded. Is more preferable.

R ¹ , R ² , R ³ and R ⁴ are more preferably a hydrogen atom from the viewpoint of further improving the storage stability and development defect suppression of the radiation-sensitive resin composition.

As said ^Rf1 and ^Rf2 , it is more preferable that it is a fluorine atom from a viewpoint of raising the storage stability and the development defect inhibitory property of the said radiation sensitive resin composition.

  [B] The compound is not particularly limited as long as it contains an anion represented by the following formula (1), and examples thereof include a compound formed by a combination of an anion and a cation represented by the following formula (2). .

In the above formula (2), X, R ^X , R ¹ , R ² , R ³ , R ⁴ , Y, Y ′, R ^f1 and R ^f2 have the same ^{meanings as} in the above formula (1). Z ⁺ is a monovalent cation.

Examples of the monovalent cation represented by Z ⁺ include cations containing elements such as S, I, O, N, P, Cl, Br, F, As, Se, Sn, Sb, Te, and Bi. Can be mentioned. Examples of the cation containing S (sulfur) as an element include a sulfonium cation and a tetrahydrothiophenium cation. Examples of the cation containing I (iodine) as an element include an iodonium cation.

  Examples of the sulfonium cation include a cation represented by the following formula (Q-1), and examples of the tetrahydrothiophenium cation include a cation represented by the following formula (Q-2). Examples of the iodonium cation include a cation represented by the following formula (Q-3).

In the above formula (Q-1), R ^c1 , R ^c2 and R ^c3 each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, substituted or unsubstituted. aromatic hydrocarbon group having 6 to 12 carbon atoms, or an -OSO ₂ -R ^{P 'or} _-SO 2 -R ^Q', or two or more are combined with each other configured ring of these groups Represents. R ^{P ′} and R ^{Q ′} each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic carbon atom having 5 to 25 carbon atoms. A hydrogen group or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. k1, k2 and k3 are each independently an integer of 0 to 5. R ^c1 to R ^c3 and R ^{P 'and} R ^Q' if there are a plurality each of the plurality of ^R c1 ^{to R c3} and R ^{P 'and} R ^Q' may have respectively the same or different.
In the above formula (Q-2), R ^d1 represents a substituted or unsubstituted linear or branched alkyl group having 1 to 8 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon having 6 to 8 carbon atoms. It is a group. k4 is an integer of 0-7. If R ^d1 is plural, the plurality of R ^d1 may be the same or different, and a plurality of R ^d1 may represent a constructed ring aligned with each other. R ^d2 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 0-6. If R ^d2 is a multiple, the plurality of R ^d2 may be the same or different, a plurality of R ^d2 may represent configured ring aligned with each other. t is an integer of 0-3.
In formula (Q-3), R ^e1 and R ^e2 each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted carbon number of 6; 12 aromatic hydrocarbon group, or an -OSO ₂ -R ^R or _-SO 2 -R ^S, or two or more are combined with each other configured ring of these groups. R ^R and R ^S are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms. Or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. k6 and k7 are each independently an integer of 0 to 5. R ^{e1, R} e2, ^R when ^R and ^{R S} is plural respective plurality of ^{R e1,} R e2, ^{R R} and ^{R S} may have respectively the same or different.

Examples of the unsubstituted linear alkyl group represented by R ^{c1 to} R ^c3 , R ^d1 , R ^d2 , R ^e1 and R ^e2 include a methyl group, an ethyl group, an n-propyl group, and an n-butyl group. Etc.
Examples of the unsubstituted branched alkyl group represented by R ^{c1 to} R ^c3 , R ^d1 , R ^d2 , R ^e1 and R ^e2 include i-propyl group, i-butyl group, sec-butyl group, t -A butyl group etc. are mentioned.
Examples of the unsubstituted aromatic hydrocarbon group represented by R ^{c1 to} R ^c3 , R ^e1 and R ^e2 include an aryl group such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, and a naphthyl group; a benzyl group, Examples include aralkyl groups such as phenethyl group.
Examples of the unsubstituted aromatic hydrocarbon group represented by R ^d1 and R ^d2 include a phenyl group, a tolyl group, and a benzyl group.

Examples of the substituent that may be substituted for the hydrogen atom of the alkyl group and aromatic hydrocarbon group include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxy group, a carboxy group, and a cyano group. Nitro group, alkoxy group, alkoxycarbonyl group, alkoxycarbonyloxy group, acyl group, acyloxy group and the like.
Among these, a halogen atom is preferable and a fluorine atom is more preferable.

The above R ^{c1 to} R ^c3 , R ^d1 , R ^d2 , R ^e1 and R ^e2 include an unsubstituted linear or branched alkyl group, a fluorinated alkyl group, and an unsubstituted monovalent aromatic hydrocarbon group. , —OSO ₂ —R ^** and —SO ₂ —R ^** are preferred, fluorinated alkyl groups and unsubstituted monovalent aromatic hydrocarbon groups are more preferred, and fluorinated alkyl groups are more preferred. R ^** is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

As k1, k2, and k3 in the formula (Q-1), integers of 0 to 2 are preferable, 0 or 1 is more preferable, and 0 is more preferable.
As k4 in the above formula (Q-2), an integer of 0 to 2 is preferable, 0 or 1 is more preferable, and 1 is more preferable. k5 is preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0.
As k6 and k7 in the formula (Q-3), an integer of 0 to 2 is preferable, 0 or 1 is more preferable, and 0 is more preferable.

  Examples of the sulfonium cation include cations represented by the following formulas (i-1) to (i-21).

  Among these, a cation represented by the above formula (i-1) and a cation represented by the above formula (i-21) are preferable.

  Examples of the tetrahydrothiophenium cation include cations represented by the following formulas (i′-1) to (i′-4).

  Among these, a cation represented by the above formula (i′-2) is preferable.

  Examples of the iodonium cation include cations represented by the following formulas (ii-1) to (ii-25).

  Among these, a cation represented by the above formula (ii-11) is preferable.

  Examples of the [B] compound include compounds represented by the following formulas (B-1) to (B-17) (hereinafter also referred to as “compound (B-1) to compound (B-17)”). It is done.

  [B] Among these, the compounds (B-1) to (B-8) are preferable, and the compound (B-6) is more preferable.

  The production method of the compound [B] which is an acid diffusion controller is represented by the following formula (c) by, for example, a reaction between a compound represented by the following formula (a) and a compound represented by the following formula (b). A step of obtaining a compound represented by the following formula (d) by hydrolysis of an ester group of the compound represented by the following formula (c), and a compound represented by the following formula (d) And a step of obtaining a compound represented by the following formula (1 ′) by reaction with a salt represented by the following formula (e).

[B] As the compound, in the above formula (2), R ² is a hydrogen atom, Y or Y ′ and R ¹ , Y or Y ′ and R ³ or Y or Y ′ and R ⁴ have a ring structure. When not formed, the following compound (1 ′) can be synthesized, for example, according to the following reaction scheme. By the said method, a [B] compound is compoundable simply and with a sufficient yield. Other [B] compounds can also be synthesized using known methods.

In the above formulas (a) to (e) and (1 ′), X is —C (═O) Y, —C (═O) OY, —C (GR ^X ) ₂ Y, —C (═O). NYY ′, —S (═O) ₂ Y, —S (═O) ₂ OY, —S (═O) ₂ NYY ′, —C (═O) OC (═O) Y or —C (═O) N (Y) C (= O) Y ′.
G is each independently an oxygen atom or a sulfur atom.
Each R ^X is independently a monovalent organic group having 1 to 20 carbon atoms, or two R ^x are combined with each other, and together with —G—C—G—, the number of ring members is 4 to 20 Of the ring structure.
R ¹ ′, R ³ ′, R ⁴ ′, Y and Y ′ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, or Y or Y ′ and R ¹ ′. , Y or Y ′ and R ³ ′, or Y or Y ′ and R ⁴ ′ constitute a ring structure having 3 to 20 ring members that is formed together with the carbon atom to which they are bonded. However, when R ¹ ′, R ³ ′ and R ⁴ ′ are monovalent organic groups, R ¹ ′, R ³ ′ and R ⁴ ′ do not contain a fluorine atom.
R ⁶ is a monovalent hydrocarbon group having 1 to 20 carbon atoms.
R ^f1 and R ^f2 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 4 carbon atoms.
Q is a chlorine atom, a bromine atom or an iodine atom.
Z ⁺ is a monovalent cation.
M ⁻ is a monovalent anion.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹ ′, R ³ ′, and R ⁴ ′ include those described above for R ¹ , R ² , R ³ , R ⁴ , Y, and Y ′. Examples thereof include the same groups as those described above.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ⁶ include the same groups as those described above for R ^A2 , R ^A3 and R ^A4 .

  [B] The lower limit of the content of the compound is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, and even more preferably 1 part by mass with respect to 100 parts by mass of the [A] polymer. [B] The upper limit of the content of the compound is preferably 25 parts by mass, more preferably 20 parts by mass, further preferably 15 parts by mass, and particularly preferably 10 parts by mass with respect to 100 parts by mass of the polymer [A]. . When the content of the [B] compound is less than the above lower limit, lithography performance such as resolution of the radiation sensitive resin composition may be deteriorated. If the content of the [B] compound exceeds the above upper limit, the sensitivity of the radiation sensitive resin composition may be lowered.

<[C] solvent>
The radiation-sensitive resin composition usually contains a [C] solvent. [C] The solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least the [B] compound, the [E] polymer, and the [D] compound contained as necessary.

  [C] Examples of the solvent include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, hydrocarbon solvents, and the like.

As an alcohol solvent, for example,
C1-C18 aliphatic monoalcohol solvents such as 4-methyl-2-pentanol and n-hexanol;
An alicyclic monoalcohol solvent having 3 to 18 carbon atoms such as cyclohexanol;
A C2-C18 polyhydric alcohol solvent such as 1,2-propylene glycol;
Examples thereof include C3-C19 polyhydric alcohol partial ether solvents such as propylene glycol monomethyl ether.

As an ether solvent, for example,
Dialkyl ether solvents such as diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, diisoamyl ether, dihexyl ether, diheptyl ether;
Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;
Aromatic ring-containing ether solvents such as diphenyl ether and anisole (methylphenyl ether) are exemplified.

Examples of ketone solvents include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, 2-heptanone (methyl-n-pentyl ketone), and ethyl-n-butyl ketone. Chain ketone solvents such as methyl-n-hexyl ketone, di-iso-butyl ketone and trimethylnonanone:
Cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone and methylcyclohexanone:
2,4-pentanedione, acetonylacetone, acetophenone and the like can be mentioned.

Examples of the amide solvent include cyclic amide solvents such as N, N′-dimethylimidazolidinone and N-methylpyrrolidone;
Examples thereof include chain amide solvents such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, and N-methylpropionamide.

Examples of ester solvents include:
Monocarboxylic acid ester solvents such as n-butyl acetate and ethyl lactate;
Polyhydric alcohol carboxylate solvents such as propylene glycol acetate;
Polyhydric alcohol partial ether carboxylate solvents such as propylene glycol monomethyl ether acetate;
lactone solvents such as γ-butyrolactone and δ-valerolactone;
Polycarboxylic acid diester solvents such as diethyl oxalate;
Examples thereof include carbonate solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, and propylene cartonate.

Examples of the hydrocarbon solvent include
an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms such as n-pentane and n-hexane;
Examples thereof include aromatic hydrocarbon solvents having 6 to 16 carbon atoms such as toluene and xylene.

  Among these, as the [C] solvent, ester solvents and ketone solvents are preferable, polyhydric alcohol partial ether carboxylate solvents, lactone solvents, and cyclic ketone solvents are more preferable, and polyhydric alcohol partial alkyl ethers. Acetate, lactone solvents, and cyclic ketone solvents are more preferable, and propylene glycol monomethyl ether acetate, γ-butyrolactone, and cyclohexanone are particularly preferable. The radiation-sensitive resin composition may contain one or more [C] solvents.

<[D] Compound>
The compound [D] is a substance that generates sulfonic acid by the action of radiation. The generated sulfonic acid dissociates the acid dissociable groups of the [E] polymer, [A] polymer and the like to generate carboxy groups and the like, and the solubility of these polymers in the developer changes. A resist pattern can be formed from the radiation-sensitive resin composition.

  Examples of the [D] compound include onium salt compounds, N-sulfonyloxyimide compounds, halogen-containing compounds, diazoketone compounds, and the like.

  Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.

  Specific examples of the compound [D] include compounds described in paragraphs [0080] to [0113] of JP2009-134088A.

  As the compound [D], a compound represented by the following formula (vi) is preferable. [D] By using the compound represented by the following formula (vi) as the compound, the acid generated by the action of radiation due to the interaction with the polar structure of the [E] polymer or [A] polymer, etc. It is considered that the diffusion length in the resist film is appropriately shortened, and as a result, the lithography performance of the radiation-sensitive resin composition can be further improved.

In the above formula (vi), R ^b1 is a monovalent group containing an alicyclic structure having 6 or more ring members or a monovalent group containing an aliphatic heterocyclic structure having 6 or more ring members. R ^b2 is a fluorinated alkanediyl group having 1 to 10 carbon atoms. T ⁺ is a monovalent radiolytic onium cation.

The “number of ring members” in R ^b1 refers to the number of atoms constituting the ring of the alicyclic structure and the aliphatic heterocyclic structure. In the case of the polycyclic alicyclic structure and the polycyclic aliphatic heterocyclic structure, The number of atoms that make up a polycycle.

Examples of the monovalent group containing an alicyclic structure having 6 or more ring members represented by R ^b1 include monovalent monocyclic alicyclic saturation such as a cyclooctyl group, a cyclononyl group, a cyclodecyl group, and a cyclododecyl group. A hydrocarbon group;
A monovalent monocyclic alicyclic unsaturated hydrocarbon group such as a cyclooctenyl group and a cyclodecenyl group;
Monovalent polycyclic alicyclic saturated hydrocarbon group such as norbornyl group, adamantyl group, tricyclodecyl group, tetracyclododecyl group;
And monovalent polycyclic alicyclic unsaturated hydrocarbon groups such as a norbornenyl group and a tricyclodecenyl group.

Examples of the monovalent group containing an aliphatic heterocyclic structure having 6 or more ring members represented by R ^b1 include a group containing a lactone structure such as a norbornanelactone-yl group;
A group containing a sultone structure such as a norbornane sultone-yl group;
An oxygen atom-containing heterocyclic group such as an oxacycloheptyl group and an oxanorbornyl group;
A nitrogen atom-containing heterocyclic group such as an azacyclohexyl group, an azacycloheptyl group, a diazabicyclooctane-yl group;
And sulfur atom-containing heterocyclic groups such as a thiacycloheptyl group and a thianorbornyl group.

The number of ring members of the group represented by R ^b1 is preferably 8 or more, more preferably 9 to 15 and even more preferably 10 to 13 from the viewpoint that the diffusion length of the acid described above becomes more appropriate.

Among these, R ^b1 is preferably a monovalent group containing an alicyclic structure having 9 or more ring members, or a monovalent group containing an aliphatic heterocyclic structure having 9 or more ring members, such as an adamantyl group or hydroxyadamantyl group. Group, norbornanelactone-yl group, and 5-oxo-4-oxatricyclo [4.3.1.1 ^3,8 ] undecan-yl group are more preferable, and an adamantyl group is more preferable.

Examples of the fluorinated alkanediyl group having 1 to 10 carbon atoms represented by R ^b2 include one or more hydrogen atoms of an alkanediyl group having 1 to 10 carbon atoms such as a methanediyl group, an ethanediyl group, and a propanediyl group. And a group in which is substituted with a fluorine atom.
Among these, SO ₃ ^- fluorinated alkane diyl group which has a fluorine atom to carbon atom is bonded to adjacent groups are preferred, SO ₃ ^- 2 fluorine atoms to the carbon atom adjacent to the group is attached More preferred are fluorinated alkanediyl groups, 1,1-difluoromethanediyl group, 1,1-difluoroethanediyl group, 1,1,3,3,3-pentafluoro-1,2-propanediyl group, 1,1 1,2,2-tetrafluoroethanediyl group, 1,1,2,2-tetrafluorobutanediyl group, and 1,1,2,2-tetrafluorohexanediyl group are more preferable.

Examples of the monovalent radiolytic onium cation represented by T ⁺ include those similar to the onium cation exemplified as Z ⁺ in the formula (2) of the compound [B].

  Examples of the compound [D] include compounds represented by the following formulas (vi-1) to (vi-17) (hereinafter also referred to as “compounds (vi-1) to (vi-17)”). It is done.

  Among these, as the compound [D], an onium salt compound is preferable, a sulfonium salt is more preferable, and compounds (vi-1) to (vi-3) and compounds (vi-13) to (vi-17) are preferable. Further preferred.

  [D] The lower limit of the content of the compound is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, further preferably 1 part by mass, with respect to 100 parts by mass of the polymer [A]. Part is particularly preferred. As said upper limit of a [D] compound, 40 mass parts is preferable with respect to 100 mass parts of [A] polymers, 30 mass parts is more preferable, 25 mass parts is further more preferable. [D] A compound can use 1 type (s) or 2 or more types.

<[E] polymer>
[E] A polymer is a polymer containing a fluorine atom. [E] The polymer preferably has at least one of the following structural unit (V) and structural unit (VI). The radiation-sensitive resin composition contains the [E] polymer, so that when the resist film is formed, the distribution is unevenly distributed on the surface of the resist film due to the oil-repellent characteristics of the [E] polymer. There exists a tendency and it can suppress that the [D] compound, an acid diffusion control agent, etc. at the time of immersion exposure elute to an immersion liquid. Further, due to the water-repellent characteristics of the [E] polymer, the advancing contact angle between the resist film and the immersion liquid can be controlled within a desired range, and the occurrence of bubble defects can be suppressed. Furthermore, the receding contact angle between the resist film and the immersion liquid becomes high, and high-speed scanning exposure is possible without leaving water droplets. Moreover, also in electron beam exposure and EUV exposure, the defect suppression property of a resist film can be improved with the water-repellent characteristic of an [E] polymer. Thus, when the said radiation sensitive resin composition contains a [E] polymer, the resist film suitable for liquid immersion exposure, electron beam exposure, EUV exposure, etc. can be formed.

  [E] The polymer preferably has a larger total mass content of fluorine atoms than the [A] polymer in the radiation-sensitive resin composition. The [E] polymer has a higher total mass content of fluorine atoms than the [A] polymer, so that the degree of uneven distribution described above becomes higher, and the resulting resist film surface has water repellency and elution suppression, etc. The characteristics can be further improved.

[E] The lower limit of the mass content of fluorine atoms in the polymer is preferably 1% by mass, more preferably 2% by mass, further preferably 4% by mass, and particularly preferably 7% by mass. The upper limit of the total mass content is preferably 60% by mass, more preferably 40% by mass, and still more preferably 30% by mass. The mass content of fluorine atoms in the polymer can be calculated from the structure of the polymer obtained by ¹³ C-NMR spectrum measurement or the like.

  [E] The polymer preferably has an alkali dissociable group. [E] When the polymer has an alkali-dissociable group, the resist film surface can be effectively changed from hydrophobic to hydrophilic during alkali development, and the development defect suppression of the radiation-sensitive resin composition is improved. . [E] When the polymer has an alkali-dissociable group, ion exchange with a conventionally used onium salt compound is likely to occur, and the storage stability and development defect suppression of the radiation-sensitive resin composition are further reduced. . However, since the radiation sensitive resin composition uses the specific [B] compound as the onium salt compound, even when the [E] polymer has an alkali dissociable group, it has storage stability and development defect suppression. It can be excellent. An “alkali dissociable group” is a group that replaces a hydrogen atom of a carboxy group, a hydroxy group, etc., and dissociates in an alkaline aqueous solution (for example, an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C.). Group.

  [E] The fluorine atom content in the polymer is not particularly limited, and may be bonded to any of the main chain, the side chain, and the terminal, but is a structural unit containing a fluorine atom (hereinafter referred to as “structural unit (V)”). It is preferable to have (also called). [E] In addition to at least one of the structural unit (V) and the structural unit (VI), the polymer contains an acid-dissociable group from the viewpoint of improving development defect suppression of the radiation-sensitive resin composition. It is preferable to have a structural unit (a structural unit (I) in the polymer [A] described later).

[Structural unit (V)]
The structural unit (V) is a structural unit represented by the following formula (5) (hereinafter also referred to as “structural unit (V-1)”). [E] A polymer can adjust a fluorine atom content rate by having a structural unit (V).

In said formula (5), ^R51 is a hydrogen atom, a C1-C10 alkyl group, or a C2-C10 alkoxyalkyl group. W is a C1-C20 divalent organic group. R ⁵² is a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. However, at least one of W and R ⁵² is a group containing a fluorine atom.

Examples of the alkyl group having 1 to 10 carbon atoms represented by ^{R 51,} a methyl group, an ethyl group, n- propyl group, and n- butyl.

Examples of the alkoxyalkyl group having 2 to 10 carbon atoms represented by R ⁵¹ include a methoxymethyl group, a methoxyethyl group, a methoxypropyl group, a methoxybutyl group, an ethoxymethyl group, an ethoxyethyl group, an ethoxypropyl group, and an ethoxybutyl group. Groups and the like.

Examples of the divalent organic group having 1 to 20 carbon atoms represented by W include, for example, one hydrogen atom from the monovalent organic group having 1 to 20 carbon atoms exemplified as R ^{15 in the} above formula (4). Excluded groups and the like.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ⁵² include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and a monovalent alicyclic group having 3 to 20 carbon atoms. Examples include hydrocarbon groups and monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, and an i-propyl group;
An alkenyl group such as an ethenyl group, a propenyl group, a butenyl group;
Examples thereof include alkynyl groups such as ethynyl group, propynyl group and butynyl group.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include monovalent monocyclic alicyclic saturated hydrocarbon groups such as a cyclopentyl group and a cyclohexyl group;
Monovalent monocyclic alicyclic unsaturated hydrocarbon groups such as a cyclopentenyl group and a cyclohexenyl group;
Monovalent polycyclic alicyclic saturated hydrocarbon groups such as a norbornyl group, an adamantyl group, a tricyclodecyl group;
And monovalent polycyclic alicyclic unsaturated hydrocarbon groups such as a norbornenyl group and a tricyclodecenyl group.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and an anthryl group;
Examples thereof include aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group and anthrylmethyl group.

The monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ⁵² is preferably a chain hydrocarbon group or an alicyclic hydrocarbon group.

Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R ⁵² include a fluorinated alkyl group having 1 to 20 carbon atoms. The monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R ⁵² is preferably a fluorine atom or a fluorinated alkyl group, more preferably a fluorine atom or a perfluoroalkyl group, and a fluorine atom or trifluoro group. More preferred is a methyl group.

Further, from the viewpoint of further improving the effect as an alkali dissociable group, it is preferable that at least one of W and R ⁵² is a group containing a fluorine atom.

  [E] When a polymer has a structural unit (V), as an upper limit of the content rate of a structural unit (V), 100 mol% is preferable with respect to all the structural units in a [E] polymer, and 95 mol% Is more preferable, and 90 mol% is still more preferable. By setting it as such a content rate, the fluorine atom content rate of an [E] polymer can be adjusted more appropriately.

[Structural unit (VI)]
The structural unit (VI) is a structural unit represented by the following formula (6) (hereinafter also referred to as “structural unit (VI)”). [E] A polymer can adjust fluorine atom content rate by having a structural unit (VI).

In said formula (6), ^Rh is a hydrogen atom, a methyl group, or a trifluoromethyl group. G is a single bond, an oxygen atom, a sulfur atom, —CO—O—, —SO ₂ —NH—, —CO—NH—, or —O—CO—NH—. R ^k is a monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms or a monovalent fluorinated alicyclic hydrocarbon group having 4 to 20 carbon atoms.

R ^h is preferably a hydrogen atom and a methyl group, more preferably a methyl group, from the viewpoint of the copolymerizability of the monomer giving the structural unit (VI).

As the _{G, -CO-O -, -} SO 2 -NH -, - CO-NH- or -O-CO-NH- are preferred, -CO-O-are more preferred.

Examples of the monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms represented by R ^k include, for example, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, 2 , 2,3,3,3-pentafluoropropyl group, 1,1,1,3,3,3-hexafluoropropyl group, perfluoro n-propyl group, perfluoro i-propyl group, perfluoro n-butyl Group, perfluoro i-butyl group, perfluoro t-butyl group, 2,2,3,3,4,4,5,5-octafluoropentyl group, perfluorohexyl group and the like.

Examples of the monovalent fluorinated alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ^k include a monofluorocyclopentyl group, a difluorocyclopentyl group, a perfluorocyclopentyl group, a monofluorocyclohexyl group, and a difluorocyclopentyl group. Perfluorocyclohexylmethyl group, fluoronorbornyl group, fluoroadamantyl group, fluorobornyl group, fluoroisobornyl group, fluorotricyclodecyl group, fluorotetracyclodecyl group and the like.

Among these, R ^k is preferably a fluorinated chain hydrocarbon group, such as 2,2,2-trifluoroethyl group, 1,1,1,3,3,3-hexafluoro-2-propyl. The group is more preferable, and the 1,1,1,3,3,3-hexafluoro-2-propyl group is more preferable.

  [E] When the polymer has a structural unit (VI), the upper limit of the content ratio of the structural unit (VI) is preferably 100 mol%, and 95 mol% with respect to all the structural units in the [E] polymer. Is more preferable, and 90 mol% is still more preferable. By setting it as such a content rate, the fluorine atom content rate of an [E] polymer can be adjusted more appropriately.

  [E] The lower limit of the content of the polymer is preferably 0.1 parts by mass, more preferably 0.2 parts by mass, and 0.5 parts by mass with respect to 100 parts by mass of the polymer [A] described later. More preferred is 1 part by mass. [E] The upper limit of the content of the polymer is preferably 30 parts by mass, more preferably 20 parts by mass, further preferably 15 parts by mass, and particularly preferably 10 parts by mass with respect to 100 parts by mass of the polymer [A]. preferable.

<[E] Polymer Synthesis Method>
[E] The polymer can be synthesized, for example, by polymerizing monomers giving each structural unit in a suitable solvent using a radical polymerization initiator or the like.

  Examples of the radical polymerization initiator include azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (3-cyclopropylpropylene). Pionitrile), 2,2′-azobis (3,4-dimethylvaleronitrile), azo radical initiators such as dimethyl 2,2′-azobisisobutyrate; benzoyl peroxide, t-butyl hydroperoxide, And peroxide radical initiators such as cumene hydroperoxide. Of these, AIBN and dimethyl 2,2'-azobisisobutyrate are preferred, and AIBN is more preferred. These radical initiators can be used alone or in combination of two or more.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane;
Cycloaliphatic saturated hydrocarbons such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane;
Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene;
Halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene;
Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate and methyl propionate;
Ketones such as acetone, methyl ethyl ketone, 4-methyl-2-pentanone, 2-heptanone;
Ethers such as tetrahydrofuran, dimethoxyethanes, diethoxyethanes;
Examples include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol. The solvent used for these polymerizations may be used alone or in combination of two or more.

  As reaction temperature in the said superposition | polymerization, 40 to 150 degreeC and 50 to 120 degreeC are preferable normally. The reaction time is usually preferably 1 hour to 48 hours and 1 hour to 24 hours.

  [E] The polystyrene-reduced weight average molecular weight (Mw) of the polymer by gel permeation chromatography (GPC) is not particularly limited, but is preferably 1,000 or more and 50,000 or less, more preferably 2,000 or more and 30,000 or less. Preferably, 2,500 or more and 20,000 or less are more preferable, and 3,000 or more and 15,000 or less are particularly preferable. [E] By making Mw of a polymer into the said range, the applicability | paintability and development defect inhibitory property of the said radiation sensitive resin composition improve. [E] If the Mw of the polymer is less than the lower limit, a resist film having sufficient heat resistance may not be obtained. [E] If the Mw of the polymer exceeds the above upper limit, the developability of the resist film may be lowered.

  [E] The ratio (Mw / Mn) of Mw to polystyrene-equivalent number average molecular weight (Mn) by gel permeation chromatography (GPC) of the polymer is usually 1 to 5, preferably 1 to 3. 1 or more and 2 or less are more preferable.

<Other optional components>
The said radiation sensitive resin composition may contain other arbitrary components other than said [A]-[E] component. As said other arbitrary components, other acid diffusion control bodies other than a [B] compound, surfactant, an alicyclic skeleton containing compound, a sensitizer, etc. are mentioned, for example. Each of these other optional components may be used alone or in combination of two or more.

[Other acid diffusion controllers]
The radiation-sensitive resin composition may contain an acid diffusion controller other than the [B] compound as long as the effects of the present invention are not impaired. The other acid diffusion controller controls the diffusion phenomenon of the acid generated from the [D] compound in the resist film by the action of radiation. As a result, there is an effect of suppressing an undesirable chemical reaction in the non-exposed region. Moreover, the storage stability of the obtained radiation sensitive resin composition further improves. Further, the resolution as a resist is further improved, and a change in the line width of the resist pattern due to a change in the holding time from exposure to development processing can be suppressed, and a radiation-sensitive resin composition excellent in process stability can be obtained. . As the inclusion form of the other acid diffusion controller in the radiation sensitive resin composition, a form of a free compound (hereinafter referred to as “other acid diffusion controller” as appropriate) is incorporated as a part of the polymer. Either of these forms may be used.

  Other acid diffusion control agents include, for example, a compound represented by the following formula (vii) (hereinafter also referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule (hereinafter, “ Nitrogen-containing compound (III) ”, compounds having three nitrogen atoms (hereinafter also referred to as“ nitrogen-containing compound (IV) ”), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like. .

In the above formula (vii), R ^f4 , R ^f5 and R ^f6 are each independently a hydrogen atom, an ^optionally substituted linear, branched or cyclic alkyl group, aryl group or aralkyl group. .

  Examples of the nitrogen-containing compound (I) include monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine and tri-n-pentylamine; and fragrances such as aniline Group amines and the like.

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

  Examples of the nitrogen-containing compound (IV) include polyamine compounds such as polyethyleneimine and polyallylamine; and polymers such as dimethylaminoethylacrylamide.

  Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like. It is done.

  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.

  Examples of the nitrogen-containing heterocyclic compound include pyridines such as pyridine and 2-methylpyridine; morpholines such as N-propylmorpholine and N- (undecan-1-ylcarbonyloxyethyl) morpholine; pyrazine, pyrazole and the like. .

  Moreover, the compound which has an acid dissociable group can also be used as said nitrogen-containing organic compound. Examples of the nitrogen-containing organic compound having such an acid dissociable group include Nt-butoxycarbonylpiperidine, Nt-butoxycarbonylimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2. -Phenylbenzimidazole, N- (t-butoxycarbonyl) di-n-octylamine, N- (t-butoxycarbonyl) diethanolamine, N- (t-butoxycarbonyl) dicyclohexylamine, N- (t-butoxycarbonyl) diphenylamine Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-amyloxycarbonyl-4-hydroxypiperidine and the like.

  Further, as another acid diffusion controller, a photodegradable base that generates a weak acid by the action of radiation can also be used. Examples of the photodegradable base include onium salt compounds that lose acid diffusion controllability by being decomposed by the action of radiation (except for those corresponding to the [B] compound).

  As content of the said other acid diffusion control body, when the said other acid diffusion control body is another acid diffusion control agent, it is 0 mass part-20 mass parts with respect to 100 mass parts of [A] polymers. Preferably, 0.1 mass part-15 mass parts are more preferable, 0.3 mass part-10 mass parts are more preferable, 0.5 mass part-5 mass parts are especially preferable. When the content of the other acid diffusion controller exceeds the upper limit, the sensitivity of the radiation sensitive resin composition may be lowered.

[Surfactant]
Surfactants have the effect of improving coatability, striation, 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 dilaurate, polyethylene glycol diacrylate. Nonionic surfactants such as stearate; commercially available products include “KP341” from Shin-Etsu Chemical Co., Ltd., “Polyflow No.75” and “No.95” from Kyoeisha Chemical Co., Ltd., “F-Top” from Tochem Products EF301, EF303, EF352, DIC's "MegaFuck F171", "F173", Sumitomo 3M's "Florard FC430", "FC431", Asahi Glass Industry's "Asahi Guard AG71""SurflonS-382","SC-101","SC-102","SC-103","SC-104","SC-105","SC-106" Etc. As content of surfactant in the said radiation sensitive resin composition, it is 2 mass parts or less normally with respect to 100 mass parts of [A] polymers.

[Alicyclic skeleton-containing compound]
The alicyclic skeleton-containing compound has an effect of improving dry etching resistance, pattern shape, adhesion to the substrate, and the like.

[Sensitizer]
The sensitizer exhibits an action of increasing the amount of acid generated from the [D] compound and the like, and has an effect of improving the “apparent sensitivity” of the radiation-sensitive resin composition.

  Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines and the like. These sensitizers may be used alone or in combination of two or more. As content of the sensitizer in the said radiation sensitive resin composition, it is 2 mass parts or less normally with respect to 100 mass parts of [A] polymers.

<Method for producing radiation-sensitive resin composition>
The method for producing the radiation-sensitive resin composition includes, for example, [A] polymer, [B] compound, [C] solvent, [D] compound, and [E] polymer contained as necessary. Mixing at a rate. The radiation-sensitive resin composition is preferably filtered after mixing with, for example, a filter having a pore size of about 0.2 μm. The total solid content concentration of the radiation-sensitive resin composition is usually 0.1% by mass to 50% by mass, preferably 0.5% by mass to 30% by mass, and more preferably 1% by mass to 20% by mass. .

  The radiation-sensitive resin composition can be used for forming a positive pattern using an alkaline developer and for forming a negative pattern using a developer containing an organic solvent. Among these, when used for forming a negative pattern using a developer containing an organic solvent, the radiation-sensitive resin composition can exhibit higher resolution.

<Method for forming resist pattern>
The resist pattern forming method includes a step of coating the radiation-sensitive resin composition on one surface side of the substrate (hereinafter also referred to as “coating step”), and a resist film obtained by the coating step. And a step of developing the exposed resist film (hereinafter also referred to as “developing step”).

[Coating process]
In this step, a resist film is formed from the radiation sensitive resin composition.

  Examples of the substrate on which the resist film is formed include a silicon wafer and a wafer coated with aluminum. A resist film is formed by applying the radiation sensitive resin composition on the substrate. Although it does not specifically limit as a coating method of the said radiation sensitive resin composition, For example, it can apply | coat by well-known methods, such as a spin coat method. When applying the radiation-sensitive resin composition, the amount of the radiation-sensitive resin composition to be applied is adjusted so that the formed resist film has a desired thickness. In addition, after apply | coating the said radiation sensitive resin composition on a board | substrate, in order to volatilize a solvent, you may perform soft baking (henceforth "SB"). The soft baking temperature is usually 30 ° C to 200 ° C, preferably 50 ° C to 150 ° C.

[Exposure process]
In this step, the resist film obtained by the coating step is exposed. In some cases, this exposure is performed by immersion exposure in which radiation is irradiated through a mask having a predetermined pattern through an immersion medium such as water.

  In the case of immersion exposure, an immersion medium is disposed on the resist film, and the resist film is irradiated with radiation through the immersion medium. As the immersion medium, a liquid having a higher refractive index than air is usually used. Specific examples include pure water, long-chain or cyclic aliphatic compounds, and the like. In a state through this immersion medium, that is, in a state in which the immersion medium is filled between the lens and the resist film, the exposure apparatus irradiates radiation and exposes the resist film through a mask having a predetermined pattern. .

  Examples of the radiation include visible rays, ultraviolet rays, far ultraviolet rays, vacuum ultraviolet rays (extreme ultraviolet rays (EUV); wavelength 13.5 nm), electromagnetic waves such as X-rays and γ rays, and charged particle beams such as electron rays and α rays. Can be mentioned. In the case of immersion exposure, far ultraviolet rays represented by ArF excimer laser light (wavelength 193 nm) and KrF excimer laser light (wavelength 248 nm) are preferable, and ArF excimer laser light (wavelength 193 nm) is more preferable.

  Moreover, you may perform post-exposure baking (PEB) after exposure. As a minimum of the temperature of PEB, it is 50 degreeC normally and 80 degreeC is preferable. The upper limit of the PEB temperature is usually 180 ° C, preferably 130 ° C. The lower limit of the PEB time is usually 5 seconds, and preferably 10 seconds. The upper limit of the PEB time is usually 600 seconds, and preferably 300 seconds.

  In the present invention, in order to maximize the potential of the radiation-sensitive composition, for example, an organic or inorganic antireflection film can be formed on the substrate to be used. Moreover, in order to prevent the influence of the basic impurity etc. which are contained in environmental atmosphere, a protective film can also be provided, for example on a coating film. When immersion exposure is performed, an immersion protective film may be provided on the film, for example, in order to avoid direct contact between the immersion medium and the film.

[Development process]
In this step, the resist film exposed in the exposure step is developed. Thereby, a resist pattern is formed.

  Examples of the developer used for the development include alkali developers such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n. -Propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5 An alkaline aqueous solution in which at least one alkaline compound such as diazabicyclo- [4.3.0] -5-nonene is dissolved is preferable. An appropriate amount of a water-soluble organic solvent such as alcohols such as methanol and ethanol and a surfactant can be added to the developer.

  Further, as the developer, a developer containing an organic solvent can be used. As said organic solvent, the 1 type (s) or 2 or more types of the organic solvent illustrated as the [C] solvent of the said radiation sensitive resin composition is mentioned, for example.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The measuring method of various physical property values is shown below.

[Weight average molecular weight (Mw), number average molecular weight (Mn) and dispersity (Mw / Mn)]
Mw and Mn of the polymer are obtained by gel permeation chromatography (GPC) using Tosoh GPC columns ("G2000HXL", "G3000HXL", "G4000HXL") under the following conditions. It was measured. The degree of dispersion (Mw / Mn) was calculated from the measurement results of Mw and Mn.

Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Column temperature: 40 ° C
Detector: Differential refractometer Standard material: Monodisperse polystyrene

[ ¹³ C-NMR analysis]
The ¹³ C-NMR analysis for determining the content ratio of each structural unit of the polymer was measured using a nuclear magnetic resonance apparatus (“JNM-ECX400” manufactured by JEOL Ltd.) and using deuterated chloroform as a measurement solvent.

<Synthesis of [A] polymer and [E] polymer>
The monomers used in the synthesis of each polymer in each example and comparative example are shown below.

  Among the above compounds, (M-1) to (M-7) and (M-16) represent the structural unit (I) as (M-8) to (M-9) and (M-11) to (M M-14) represents the structural unit (II), (M-15) represents the structural unit (III), (M-10) represents the structural unit (IV), and (M-17) represents the structural unit (VI). Compound (M-18) gives the structural unit (V), respectively.

[Synthesis Example 1] (Synthesis of polymer (A-1))
As shown in Table 1 below, 9.38 g (50 mol%) of compound (M-1) and 10.62 g (50 mol%) of compound (M-8) were dissolved in 40 g of 2-butanone, and further a polymerization initiator. As a solution, 0.785 g of azobisisobutyronitrile (5 mol% based on the total monomers) was dissolved to prepare a monomer solution. Next, a 200 mL three-necked flask containing 20 g of 2-butanone was heated to 80 ° C. with stirring in a nitrogen atmosphere, and the prepared monomer solution was added dropwise over 3 hours. After completion of the dropwise addition, the polymerization reaction was carried out by heating at 80 ° C. for 3 hours. After completion of the polymerization reaction, the reaction solution was cooled to room temperature, poured into 300 g of methanol, and the precipitated solid was separated by filtration. The solid separated by filtration was washed twice with 60 mL of methanol, filtered, and then dried under reduced pressure at 50 ° C. for 15 hours to synthesize polymer (A-1) (yield 15.8 g, yield 78.9). %). Mw of the polymer (A-1) was 6,100, and Mw / Mn was 1.41. As a result of ¹³ C-NMR analysis, the content ratios of the structural units derived from the compound (M-1) and the compound (M-8) were 49.8 mol% and 50.2 mol%, respectively.

[Synthesis Examples 2 to 7] (Synthesis of polymers (A-2) to (A-7))
Polymers (A-2) to (A-7) shown in Table 1 below are obtained by performing the same operations as in Synthesis Example 1 except that the types and amounts of monomers shown in Table 1 are used. Synthesized.

[Synthesis Example 8] (Synthesis of polymer (A-8))
As shown in Table 1 below, 54.76 g (50 mol%) of the compound (M-1), 45.24 g (50 mol%) of the compound (M-15), and azobisisobutyronitrile as a polymerization initiator. 58 g (5 mol% based on the total monomers) and t-dodecyl mercaptan 1 and 14 g were dissolved in 100 g of propylene glycol monomethyl ether, and the reaction temperature was maintained at 70 ° C. in a nitrogen atmosphere for 16 hours. I let you. After completion of the polymerization reaction, the polymerization solution was dropped into 1,000 g of n-hexane for coagulation purification, and 150 g of propylene glycol monomethyl ether was added again to the obtained solid, and further 150 g of methanol, 34 g of triethylamine and 6 g of water were added. In addition, the hydrolysis reaction was carried out for 8 hours while refluxing at the boiling point. After completion of the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the resulting solid was dissolved in 150 g of acetone, then dropped into 2,000 g of water to solidify, and the resulting solid was filtered and filtered at 50 ° C. for 17 hours. By drying, a white powdery polymer (A-8) was obtained (yield 63.8 g, yield 72.3%). Mw of the polymer (A-8) was 6400, and Mw / Mn was 1.72. As a result of ¹³ C-NMR analysis, the content ratios of the structural units derived from the compound (M-1) and the compound (M-15) were 51.2 mol% and 48.8 mol%, respectively.

[Synthesis Example 9] (Synthesis of Polymer (E-1))
As shown in Table 2 below, 5.16 g (20 mol%) of the compound (M-16) and 11.46 g (40 mol%) of the compound (M-17), 13.38 g (40 mol) of the compound (M-18) %) Was dissolved in 20 g of 2-butanone, and 1.16 g of azobisisobutyronitrile (5 mol% based on the total monomers) was further dissolved as a polymerization initiator to prepare a monomer solution. Next, a 100 mL three-necked flask containing 10 g of 2-butanone was heated to 80 ° C. with stirring in a nitrogen atmosphere, and the prepared monomer solution was added dropwise over 3 hours. After completion of the dropwise addition, the polymerization reaction was carried out by heating at 80 ° C. for 3 hours. After completion of the polymerization reaction, the reaction solution was cooled to room temperature. After the reaction solution was transferred to a separatory funnel, the reaction solution was uniformly diluted with 45 g of n-hexane, and 180 g of methanol was added and mixed. Next, 9 g of distilled water was added, and the mixture was further stirred and allowed to stand for 30 minutes. Next, the lower layer was recovered, and the solvent was replaced with propylene glycol monomethyl ether acetate to obtain a propylene glycol monomethyl ether acetate solution containing the polymer (E-1) as a solid content (yield 72.0%). . Mw of the polymer (E-1) was 7,300, and Mw / Mn was 2.00. As a result of ¹³ C-NMR analysis, the content of each structural unit derived from the compound (M-16), the compound (M-17) and the compound (M-18) was 20.1 mol% and 38.9 mol, respectively. %, 41.0 mol%.

<Synthesis of [B] Compound>
[Synthesis Example 10] (Synthesis of Compound (B-1))
To a 200 mL round bottom flask, add 3.30 g (34 mmol) of 2-cyclohexen-1-one, 12.64 g (62.3 mmol) of ethyl bromodifluoroacetate, 4.64 g (74 mmol) of copper powder, and 40 mL of tetrahydrofuran. And stirred at 50 ° C. Tetramethylethylenediamine (2.03 g, 17.5 mmol) and acetic acid (1.89 g, 34.3 mmol) were added dropwise in this order. After completion of dropping, the mixture was stirred for 8 hours under reflux conditions. Saturated aqueous ammonium chloride was added to stop the reaction, ethyl acetate was added, and the organic layer was washed twice with saturated aqueous ammonium chloride. After the solvent was distilled off, the residue was purified by column chromatography to obtain 7.17 g of intermediate (B′-1) (yield 95%).

  Next, 7.17 g (32.6 mmol) of the intermediate (B′-1) and 50 mL of THF were added to a 200 mL round bottom flask and stirred at room temperature. Thereto, an aqueous solution in which 0.94 g (39.1 mmol) of lithium hydroxide was dissolved in 17.9 g of water was dropped. After completion of dropping, the mixture was stirred at room temperature for 2 hours. Triphenylsulfonium chloride 9.74g (32.6mmol), dichloromethane 240mL, and water 120mL were added there, and it stirred at room temperature for 10 hours. The organic layer was collected and washed 3 times with water. After the solvent was distilled off, the residue was purified by column chromatography to obtain 5.46 g (yield 35%) of compound (B-1).

[Synthesis Examples 2 to 13] (Synthesis of Compounds (B-2) to (B-4) and (B-7) to (B-13))
A compound represented by the following formulas (B-2) to (B-4) and (B-7) to (B-13) is selected by appropriately selecting a precursor and performing the same operation as in Synthesis Example 1. Synthesized.

[Synthesis Example 5] (Synthesis of Compound (B-5))
In a 200 mL round bottom flask, 8.82 g (45.4 mmol) of compound (B-2) obtained in the same manner as in Synthesis Example 1, 10.73 g (90.8 mmol) of pinacol, paratoluenesulfonic acid monohydrate 0.86 g (4.54 mmol) and 250 mL of toluene were added, and the mixture was stirred for 12 hours under reflux conditions. After cooling to room temperature, it was washed twice with a saturated aqueous sodium hydrogen carbonate solution. After the solvent was distilled off, the residue was purified by column chromatography to obtain 3.61 g of intermediate (B ″ -5) (yield 27%). Next, intermediate (B) described in Synthesis Example 1 was obtained. A compound represented by the following formula compound (B-5) was synthesized by the same operation as the method for obtaining the compound (B-1) from '-1).

[Synthesis Example 6] (Synthesis of Compound (B-6))
The compound represented by the following formula (B-6) was synthesized by performing the same operation as in Synthesis Example 5.

<Preparation of radiation-sensitive resin composition>
Other acid diffusion control agents, [C] solvents and [D] compounds used in the preparation of the radiation sensitive resin compositions of the following Examples and Comparative Examples are shown below.

[Other acid diffusion control agents]
As other acid diffusion control agents, compounds represented by (BB-1) to (BB-2) which are photodegradable bases were used.

[[C] solvent]
C-1: Propylene glycol monomethyl ether acetate C-2: Cyclohexanone C-3: γ-butyrolactone

[[D] Compound]
[D] Compounds represented by the following (D-1) to (D-6) were used.

<Formation of resist pattern (1)> (ArF exposure, alkali development)
[Example 1]
100 parts by mass of polymer (A-1), 7.9 parts by mass of compound (D-1), 1.6 parts by mass of compound (B-1), 3.0 parts by mass of polymer (E-1), solvent ( C-1) By mixing 2,240 parts by mass, 960 parts by mass of solvent (C-2) and 30 parts by mass of solvent (C-3), and filtering the resulting mixed solution with a filter having a pore size of 0.20 μm. The radiation sensitive resin composition of Example 1 was prepared.

[Examples 2 to 24 and Comparative Examples 1 and 2]
Except having used each component of the kind and compounding quantity which are shown in following Table 3, it operated similarly to Example 1 and prepared the radiation sensitive resin composition of Examples 2-24 and Comparative Examples 1-2.

  On the surface of a 12-inch silicon wafer, using a spin coater (“CLEAN TRACK ACT12” manufactured by Tokyo Electron), a composition for forming a lower antireflection film (“ARC66” manufactured by Brewer Science) was applied at 205 ° C. Was heated for 60 seconds to form a lower antireflection film having an average thickness of 105 nm. On the lower antireflection film, each of the prepared radiation sensitive resin compositions was applied using the spin coater, and PB was performed at 90 ° C. for 60 seconds. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with an average thickness of 90 nm. Next, this resist film was subjected to an optical condition of NA = 1.3 and dipole (Sigma 0.977 / 0.782) using an ArF excimer laser immersion exposure apparatus (“NSR-S610C” manufactured by NIKON). , Exposed through a 40 nm line and space (1L1S) mask pattern. After the exposure, PEB was performed at 90 ° C. for 60 seconds. Thereafter, the resist was alkali-developed using a 2.38 mass% TMAH aqueous solution as an alkali developer, washed with water, and dried to form a positive resist pattern. When this resist pattern is formed, the exposure amount when the pattern formed through a one-to-one line and space mask with a target dimension of 40 nm is formed into a one-to-one line and space with a line width of 40 nm is the optimum exposure amount. It was.

<Evaluation of resist pattern (1) (ArF exposure, alkali development)>
Each radiation sensitive resin composition was evaluated by measuring the resist patterns formed for Examples 1 to 24 and Comparative Examples 1 to 2 (ArF exposure, alkali development) according to the following methods. A scanning electron microscope (Hitachi High-Technologies “CG-4100”) was used for measuring the resist pattern.

[Development defect suppression]
In the resist pattern resolved at the optimum exposure amount, the number of defects was measured using a defect inspection apparatus (“KLA2810” manufactured by KLA-Tencor). The defect suppression is better as the number of defects per unit area is smaller.

[WM (water mark) defect suppression]
Similar to the above method, a resist film having an average thickness of 90 nm was formed. Next, this resist film was subjected to an optical condition of NA = 1.3, dipole (Sigma 0.977 / 0.782), 568 nm / s using an ArF excimer laser immersion exposure apparatus (“XT1900i” manufactured by ASML). Exposure at a scan speed of. Then, after leaving still for 60 seconds at the time of PIR (post-immersion rinse) after exposure, PEB was performed at 90 ° C. for 60 seconds. Thereafter, the resist was developed with an alkali using an aqueous 2.38 mass% TMAH solution as an alkali developer, washed with water, and dried to form a positive resist pattern for WM defect evaluation. When this resist pattern is formed, the exposure amount when the pattern formed through a one-to-one line and space mask with a target dimension of 40 nm is formed into a one-to-one line and space with a line width of 40 nm is the optimum exposure amount. It was.

  Next, the number of defects in the resist pattern resolved at the optimum exposure amount was measured using a defect inspection apparatus (“KLA2810” manufactured by KLA-Tencor). Among the defects, missing type defects were counted as WM defects. The defect suppression is better as the number of defects per unit area is smaller.

[Storage stability (1)]
About the radiation-sensitive resin composition immediately after the preparation and the radiation-sensitive resin composition after being stored at 25 ° C. for 3 months after the preparation, the pattern formed through a 40 nm one-to-one line and space mask has a line width After measuring the exposure amount (optimal exposure amount) when formed in a 40 nm one-to-one line and space, and storing the optimal exposure amount of the radiation-sensitive resin composition immediately after preparation as Ea, and 3 months after preparation The optimum exposure amount of the radiation sensitive resin composition was defined as Eb. Then, (Ea−Eb) × 100 / Ea was calculated and used as an index of storage stability. The storage stability can be evaluated as good when (Ea−Eb) × 100 / Ea is −1.00 or more and 1.00 or less, and poor when it is less than −1.00 or exceeds 1.00. .

[Storage stability (2)]
After storing Examples (J-1) to (J-24) and Comparative Examples (JJ-1) to (JJ-2) of the above photoresist compositions at 35 ° C. for 3 months, the turbidity of the solution was visually observed. Confirmed.

  The evaluation results of the resist pattern (1) (ArF exposure, alkali development) formed from Examples 1 to 24 and Comparative Examples 1 to 2 are shown in Table 4 below.

<Resist pattern formation (3)> (electron beam exposure, alkali development)
[Example 25]
100 parts by mass of polymer (A-8), 20 parts by mass of compound (D-3), 3.2 parts by mass of compound (B-1), 4,280 parts by mass of solvent (C-1) and solvent (C-2) ) 1,830 parts by mass were blended and filtered through a membrane filter having a pore size of 0.2 μm to prepare a radiation sensitive resin composition of Example 25.

[Examples 26 to 28 and Comparative Examples 3 to 4]
Except having used each component of the kind and compounding quantity which are shown in following Table 5, it operated similarly to Example 25 and prepared the radiation sensitive resin composition of Examples 26-28 and Comparative Examples 3-4.

Next, each radiation sensitive resin composition described in Table 5 above was applied to the surface of an 8-inch silicon wafer using a spin coater (“CLEAN TRACK ACT8” manufactured by Tokyo Electron Ltd.), and PB was applied at 90 ° C. for 60 seconds. Went. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with an average thickness of 50 nm. Next, the resist film was irradiated with an electron beam by using a simple electron beam drawing apparatus (“HL800D” manufactured by Hitachi, Ltd., output: 50 KeV, current density: 5.0 A / cm ² ). After irradiation, PEB was performed at 120 ° C. for 60 seconds. Thereafter, development was performed at 23 ° C. for 30 seconds using a 2.38 mass% TMAH aqueous solution as an alkali developer, washed with water, and dried to form a positive resist pattern.

<Evaluation of resist pattern (3) (electron beam exposure, alkali development)>
About the resist pattern formed about each of Examples 25-28 and Comparative Examples 3-4 (electron beam exposure, alkali development), by measuring according to the following method, by the same method as the case of the ArF exposure, the development defect suppression property And storage stability (1) was evaluated. Similarly to the above, as the evaluation of storage stability (2), the radiation-sensitive resin compositions (J-30) to (J-33) and (JJ-3) to (JJ-4) were treated at 35 ° C. for 3 months. After storage, the turbidity of the solution was visually confirmed.

  The evaluation results of the resist pattern (3) (electron beam exposure, alkali development) formed from Examples 25 to 28 and Comparative Examples 3 to 4 are shown in Table 6 below.

  As is clear from the results in Tables 4 and 6, the radiation-sensitive resin compositions of the examples are based on the optimum exposure dose after storage at room temperature for 3 months in ArF exposure. It was excellent in all the evaluation items of storage stability (1) and storage stability (2) based on white turbidity after storage at 35 ° C. for 3 months. Moreover, the radiation sensitive resin composition of an Example was excellent in all the evaluation items of development defect inhibitory property and the said storage stability (1), (2) in electron beam exposure.

  On the other hand, in Comparative Example 1 which does not contain a fluorine atom in ArF exposure, it was inferior in all items, and in particular, WM defect suppression and storage stability were very inferior. In Comparative Example 2 containing 6 fluorine atoms, the WM defect suppression and storage stability (2) were excellent, but the development defect suppression and storage stability (1) were very poor. In Comparative Example 3 containing no fluorine atom in electron beam exposure, the development defect suppression was excellent, but the storage stability (1) and (2) was very poor. Further, in Comparative Example 4 containing 6 fluorine atoms, the storage stability (2) was excellent, but the development defect suppression property was very inferior. Generally, according to electron beam exposure, it is known to show the same tendency as in the case of EUV exposure. Therefore, according to the radiation-sensitive resin composition of the example, even in the case of EUV exposure, It is presumed to be excellent in development defect suppression, watermark defect suppression, storage stability, and the like.

  According to the radiation sensitive resin composition and the resist pattern forming method of the present invention, a resist pattern excellent in development defect suppression, watermark defect suppression, and storage stability can be formed. Therefore, they can be suitably used for pattern formation in semiconductor device manufacturing or the like where further miniaturization is expected.

Claims (8)

A first polymer having an acid dissociable group;
A first compound having an anion represented by the following formula (1);
A radiation-sensitive resin composition containing a solvent.

(In formula (1), X, -C (= O) Y, -C (= O) OY, -C (GR X) 2 Y, -C (= O) NYY ', - S (= O) ₂ Y, —S (═O) ₂ OY, —S (═O) ₂ NYY ′, —C (═O) OC (═O) Y or —C (═O) N (Y) C (═O) Y ′, G is each independently an oxygen atom or a sulfur atom, R ^X is each independently a monovalent organic group having 1 to 20 carbon atoms, or two R ^x are Together with -G-C-G-, which are combined with each other, form a ring structure having 4 to 20 ring members, R ¹ , R ² , R ³ , R ⁴ , Y and Y ′ are each independently A hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, or Y or Y ′ and R ¹ , Y or Y ′ and R ² , Y or Y ′ and R ^3, or Y or Y ′ and R ⁴ Are To form a ring structure having 3 to 20 ring members together with the carbon atom to which they are bonded, provided that when R ^{1 to} R ⁴ are monovalent organic groups, R ^{1 to} R ⁴ are fluorine atoms. R ^f1 and R ^f2 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 4 carbon atoms.) A second compound that generates sulfonic acid by the action of radiation;
The radiation sensitive resin composition according to claim 1, wherein the first compound is represented by the following formula (2).

(In the formula ^{(2), X, R X} , R 1, R 2, R 3, R 4, Y, Y ', R f1 and ^{R f2} are .Z ⁺ is as defined in the above formula (1), It is a monovalent cation.) The formula (1) and the above formula X is in (2), -C (= O ) Y, -C (= O) OY, -C (GR X) 2 Y, -S (= O) 2 Y, - S (= O) ₂ OY, —S (═O) ₂ NYY ′, —C (═O) OC (═O) Y or —C (═O) N (Y) C (═O) Y ′. , R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, or Y or Y ′ and R ¹ , Y or Y ′ and R ² , Y or Y ′ and R ³ or Y or The radiation-sensitive property according to claim 1 or 2, wherein Y 'and R ⁴ represent an alicyclic structure or an aliphatic heterocyclic structure having 3 to 20 ring members constituted together with a carbon atom to which they are combined and bonded to each other. Resin composition. The radiation sensitive resin composition according to claim 1, 2 or 3, wherein R ^f1 and R ^f2 in the formula (1) and the formula (2) are fluorine atoms. The radiation sensitive resin composition according to any one of claims 1 to 4, wherein the first polymer has a structural unit represented by the following formula (3).

(In Formula (3), R ^A1 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ^A2 is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^A3 and R ^A4 is each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, a hydrogen atom or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, or these groups are combined with each other. (Represents a ring structure having 3 to 20 ring members and a carbon atom to be bonded.) A step of applying the radiation-sensitive resin composition according to any one of claims 1 to 5 on one surface side of the substrate;
Exposing the resist film obtained by the coating process;
And a step of developing the exposed resist film. A method for producing an acid diffusion controller used in a radiation sensitive resin composition,
A step of obtaining a compound represented by the following formula (c) by a reaction of a compound represented by the following formula (a) and a compound represented by the following formula (b);
A step of obtaining a compound represented by the following formula (d) by hydrolysis of an ester group of the compound represented by the following formula (c);
The process of obtaining the compound represented by a following formula (1 ') by reaction with the salt represented by the following formula (d) and the compound represented by a following formula (d). .

(In the formulas (a) to (e) and (1 ′), X represents —C (═O) Y, —C (═O) OY, —C (GR ^X ) ₂ Y, —C (═O). NYY ′, —S (═O) ₂ Y, —S (═O) ₂ OY, —S (═O) ₂ NYY ′, —C (═O) OC (═O) Y or —C (═O) N (Y) C (═O) Y ′, G is each independently an oxygen atom or a sulfur atom, and R ^X is each independently a monovalent organic group having 1 to 20 carbon atoms. Or two R ^x are combined with each other to form a ring structure having 4 to 20 ring members together with —G—C—G—, in which R ¹ ′, R ³ ′, R ⁴ ′, Y and Y ′ is independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, or Y or Y ′ and R ¹ ′, Y or Y ′ and R ³ ′, or Y or Y ′. and ^{R 4} 'is, together with each other Which constitutes the ring structure formed ring members 3 to 20 together with the carbon atoms to which they are attached. However, R ^{1 ',} R 3' and, R 4 ^'when it is a monovalent organic group, R ^1' , R ³ ′ and R ⁴ ′ do not contain a fluorine atom, R ⁶ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ^f1 and R ^f2 are each independently a fluorine atom or A monovalent fluorinated hydrocarbon group having 1 to 4 carbon atoms, Q is a chlorine atom, a bromine atom or an iodine atom, Z ⁺ is a monovalent cation, M ⁻ is a monovalent anion. .) A first polymer having an acid dissociable group;
A compound represented by the following formula (1);
The manufacturing method of a radiation sensitive resin composition provided with the process of mixing with a solvent.

(In formula (1), X, -C (= O) Y, -C (= O) OY, -C (GR X) 2 Y, -C (= O) NYY ', - S (= O) ₂ Y, —S (═O) ₂ OY, —S (═O) ₂ NYY ′, —C (═O) OC (═O) Y or —C (═O) N (Y) C (═O) Y ′, G is each independently an oxygen atom or a sulfur atom, R ^X is each independently a monovalent organic group having 1 to 20 carbon atoms, or two R ^x are Together with -G-C-G-, which are combined with each other, form a ring structure having 4 to 20 ring members, R ¹ , R ² , R ³ , R ⁴ , Y and Y ′ are each independently A hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, or Y or Y ′ and R ¹ , Y or Y ′ and R ² , Y or Y ′ and R ^3, or Y or Y ′ and R ⁴ Are To form a ring structure having 3 to 20 ring members together with the carbon atom to which they are bonded, provided that when R ^{1 to} R ⁴ are monovalent organic groups, R ^{1 to} R ⁴ are fluorine atoms. R ^f1 and R ^f2 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 4 carbon atoms.)