JP5655563B2 - Radiation sensitive resin composition and pattern forming method - Google Patents

Radiation sensitive resin composition and pattern forming method Download PDF

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JP5655563B2
JP5655563B2 JP2010294319A JP2010294319A JP5655563B2 JP 5655563 B2 JP5655563 B2 JP 5655563B2 JP 2010294319 A JP2010294319 A JP 2010294319A JP 2010294319 A JP2010294319 A JP 2010294319A JP 5655563 B2 JP5655563 B2 JP 5655563B2
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研 丸山
研 丸山
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Jsr株式会社
Jsr株式会社
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Description

  The present invention relates to a radiation-sensitive resin composition and a pattern forming method.

  A chemically amplified radiation-sensitive resin composition used for microfabrication by lithography generates an acid in an exposed area by irradiation with visible light or ultraviolet light, and an exposed area and an unexposed area by a chemical reaction using this acid as a catalyst. This is a composition that causes a difference in the dissolution rate of each in the developing solution to form a resist pattern on the substrate.

  The radiation-sensitive resin composition is required to improve resolution performance and pattern shape as processing technology becomes finer. In response to this requirement, the types and molecular structures of polymers, acid generators and other components used in the composition have been studied, and further their combinations have been studied in detail (Japanese Patent Application Laid-Open No. 11-125907, special features). (See Kaihei 08-146610, JP 2000-298347)

  However, at present, when the miniaturization of the resist pattern has progressed to a level of a line width of 90 nm or less, the resolution performance and pattern shape performance are not sufficiently satisfied. In particular, there is a need for a radiation-sensitive resin composition that can achieve various lithography performances such as MEEF (Mask Error Enhancement Factor) performance, LWR (Line Width Roughness) performance, and pattern collapse resistance at a high level.

Japanese Patent Laid-Open No. 11-125907 Japanese Patent Laid-Open No. 08-146610 JP 2000-298347 A

  The present invention has been made based on the above circumstances, and its object is to provide a radiation-sensitive resin composition having excellent lithography performance such as MEEF performance and LWR performance, and excellent pattern collapse resistance. It is.

The invention made to solve the above problems is
[A] a polymer having a structural unit represented by the following formula (1) (hereinafter also referred to as “[A] polymer”),
[B] Irradiation generates sulfonic acid, carboxylic acid or sulfonamide, and at least one fluorine atom or perfluoroalkyl group in which the sulfonic acid, carboxylic acid and sulfonamide are bonded to the α-position carbon atom. Compound (hereinafter also referred to as “[B] compound”), and [C] irradiation with radiation generates sulfonic acid, carboxylic acid or sulfonamide, and the sulfonic acid, carboxylic acid and sulfonamide are in the α-position. A compound having neither a fluorine atom bonded to a carbon atom nor a perfluoroalkyl group (hereinafter also referred to as “[C] compound”).
Is a radiation-sensitive resin composition.
(In Formula (1), R 1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R 2 , R 3 and R 4 are each independently a straight chain having 1 to 10 carbon atoms. A branched or branched alkyl group, provided that R 2 , R 3 and R 4 are not all methyl groups.)

  The radiation-sensitive resin composition of the present invention generates an [A] polymer having an acid-dissociable group having the above specific structure and an acid having a fluorine atom or a perfluoroalkyl group at the α-position upon irradiation with radiation [B]. By including a compound and a [C] compound that generates an acid having neither a fluorine atom nor a perfluoroalkyl group at the α-position, it has excellent lithography performance such as MEEF performance and LWR performance, and an excellent pattern Can exhibit fall resistance. The reason why the radiation-sensitive resin composition can exhibit the above-described characteristics by the above configuration is not necessarily clear, but can be considered as follows, for example. The compound [B] generates a strong acid in the exposed area to dissociate the acid dissociable group of the polymer [A] to form a resist pattern. On the other hand, the [C] compound generates a weaker acid in the exposed area, adjusts the strength of the acid in the exposed area, and can moderate the dissociation rate of the acid dissociable group. In addition, since the acid generated from the [C] compound is a relatively weak acid, it is considered that the [C] compound acts as a base and has a property of capturing the acid. While the acid diffusing from the portion is captured, the above properties disappear because the exposed portion is converted into an acid. As a result, the [C] compound exhibits an advanced acid diffusion control function. In addition, the acid dissociable group of the polymer [A] does not contain a cyclic structure and is a branched structure group having a relatively small number of carbon atoms, so that this acid dissociable group and the relatively polar [B] Since the interaction between the compound and the [C] compound becomes strong, it is considered that the compatibility is improved and the dispersibility of both compounds is enhanced.

[C] It is preferable that a compound is represented by following formula (2).
(In formula (2), Q + is a monovalent onium cation. Y is a monovalent carboxylate anion, sulfonate anion or sulfonamide anion.)

In addition, Y in the above formula (2) is preferably a monovalent carboxylate anion. According to the radiation sensitive resin composition, by using an onium carboxylate compound, an onium sulfonate compound or an onium sulfonamide compound, more preferably an onium carboxylate compound as the [C] compound, A high acid scavenging function due to these anions is exhibited, and in the exposed area, the acid scavenging function is sufficiently extinguished due to high sensitivity, so that a more advanced acid diffusion control function is exhibited. As a result, MEEF performance, LWR performance, and pattern collapse resistance can be further improved.

Q + in the above formula (2) is preferably represented by the following formula (S1).
(In formula (S1), R a1 , R b1 and R c1 each independently represent a hydroxyl group, a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, —S—R A1 , —OSO 2 —R B1. Or —SO 2 —R C1 , R A1 represents an alkyl group or an aryl group, and R B1 and R C1 each independently represents an alkyl group, a cycloalkyl group, an alkoxy group, or an aryl group. Some or all of the hydrogen atoms of the alkyl group, cycloalkyl group, alkoxy group and aryl group of R a1 , R b1 and R c1 and R A1 , R B1 and R C1 may be substituted. p1 is each independently an integer of 0 to 5, provided that m1 + n1 + p1 ≧ 1 When there are a plurality of R a1 , R b1 and R c1 , The plurality of R a1 , R b1 and R c1 may be the same or different, provided that at least one of R a1 , R b1 and R c1 is —OSO 2 —R B1 or —SO 2 —R. C1 .)

  According to the radiation sensitive resin composition, in the onium salt of the [C] compound, by using the sulfonium cation having the specific structure as a cation, the [C] compound has compatibility with the [A] polymer. This improves the dispersibility in the resist film, and as a result, the LWR, MEEF and resist pattern collapse resistance can be further improved.

[B] The compound is preferably represented by the following formula (3).
(In Formula (3), M + is a monovalent onium cation. X is a monovalent sulfonate anion.)

  According to the radiation sensitive resin composition, by using an onium sulfonate compound as the [B] compound, the acid generation sensitivity of the [B] compound and the strength of the generated acid are improved. Therefore, the MEEF performance, LWR Performance and pattern collapse resistance can be further improved.

Q + in the above formula (3) is preferably represented by the following formula (S2).
(In the formula (S2), R a2 , R b2 and R c2 each independently represent a hydroxyl group, a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, -S-R A2 , -OSO 2 -R B2 Or —SO 2 —R C2 , R A2 is an alkyl group or an aryl group, and R B2 and R C2 are each independently an alkyl group, a cycloalkyl group, an alkoxy group, or an aryl group. Some or all of the hydrogen atoms of the alkyl group, cycloalkyl group, alkoxy group and aryl group of R a2 , R b2 and R c2 and R A2 , R B2 and R C2 may be substituted. p2 is each independently an integer of 0 to 5, provided that m2 + n2 + p2 ≧ 1, when a plurality of R a2 , R b2 and R c2 are present, The plurality of R a2 , R b2 and R c2 may be the same or different, provided that at least one of R a2 , R b2 and R c2 is —OSO 2 —R B2 or —SO 2 —R. C2 .)

  According to the radiation sensitive resin composition, in the onium sulfonate compound of the [B] compound, the sulfonium cation having the above specific structure is used as the cation, as in the case of the above [C] compound. Can improve the compatibility with the [A] polymer and increase the dispersibility in the resist film. As a result, the LWR, MEEF and pattern collapse resistance can be further improved.

The pattern forming method of the present invention comprises:
(1) The process of forming a coating film on a board | substrate using the said radiation sensitive resin composition,
(2) A step of irradiating at least a part of the coating film with radiation,
(3) a step of heating the coating film irradiated with the radiation; and (4) a step of developing the heated coating film.

  According to the pattern forming method, by using the radiation-sensitive resin composition, a resist pattern having excellent MEEF performance and LWR performance and excellent pattern collapse resistance can be formed.

  As described above, the radiation-sensitive resin composition of the present invention comprises a polymer having an acid-dissociable group having a specific structure and two types of compounds that generate different acids depending on the presence or absence of a fluorine atom at the α-position. By combining, it is excellent in MEEF performance and LWR performance, and can exhibit excellent pattern collapse resistance.

<Radiation sensitive resin composition>
The radiation sensitive resin composition of this invention contains a [A] polymer, a [B] compound, and a [C] compound. Moreover, the said radiation sensitive resin composition may contain arbitrary components in the range which does not impair the effect of this invention. Hereinafter, each component will be described.

<[A] polymer>
[A] polymer in this invention has a structural unit (henceforth "structural unit (I)") represented by the said Formula (1). Moreover, the [A] polymer may have other structural units, such as structural unit (II) containing a lactone structure etc.

[Structural unit (I)]
[A] The polymer has the structural unit (I) represented by the above formula (1). [A] Since the polymer has the structural unit (I), the compatibility with the [B] compound and the [C] compound described later is improved, and the MEEF performance, LWR performance and pattern of the radiation-sensitive resin composition. Fall resistance can be demonstrated at a high level.

In said formula (1), R < 1 > is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, a hydrogen atom or a methyl group is preferable, and a methyl group is more preferable from the viewpoint of increasing the copolymerizability of the monomer that gives the structural unit (I).

Examples of the linear or branched alkyl group having 1 to 10 carbon atoms represented by R 2 , R 3 and R 4 in the above formula (1) include a methyl group, an ethyl group, an n-propyl group, i -Propyl group, 1-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, i-pentyl group, sec-pentyl group, neo-pentyl group, tert-pentyl group, n -Hexyl group, i-hexyl group, n-heptyl group, i-heptyl group, n-octyl group, i-octyl group, n-nonyl group, i-nonyl group, n-decyl group, i-decyl group, etc. Can be mentioned.

As R 2 , R 3 and R 4 , the smaller the number of carbon atoms in the acid dissociable group, the better the dispersibility of the [A] polymer and [B] compound in the resulting resist film. As a result, the performance of MEEF and the like is further improved. R 2 , R 3 and R 4 are preferably a linear or branched alkyl group having 1 to 8 carbon atoms, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, and the number of carbon atoms 1-4 linear or branched alkyl groups are more preferred, and a methyl group or ethyl group is particularly preferred.

There is no case where all of R 2 , R 3 and R 4 are methyl groups. That is, the acid dissociable group in the above formula (1) is not a tert-butyl group. In addition, when the acid dissociable group is a tert-butyl group, the acid dissociation property is greatly reduced. As a result, the MEEF performance, the LWR performance, and the pattern collapse resistance of the radiation-sensitive resin composition are all deteriorated.

  Specific examples of the structural unit (I) include structural units represented by the following formula.

  Among these, the acid-dissociable group having a smaller number of carbon atoms tends to improve the LWR performance. Therefore, as the acid-dissociable group, 1,1-dimethyl-1-propyl group or 1-methyl- A structural unit having a 1-ethyl-1-propyl group is preferable, and a structural unit having a 1,1-dimethyl-1-propyl group is more preferable.

  In the [A] polymer, the content of the structural unit (I) is preferably 10 mol% or more, more preferably 20 to 80 mol%, more preferably 30 to 30 mol% with respect to all the structural units constituting the [A] polymer. 70 mol% is more preferable, and 30 to 60 mol% is particularly preferable. By making the content rate of structural unit (I) into the said range, other lithography performances, such as MEEF of the resist pattern obtained, further improve. [A] The polymer may contain one or more structural units (I) alone.

[Structural unit (II)]
[A] The polymer preferably further has a structural unit containing at least one structure selected from the group consisting of a lactone structure and a cyclic carbonate structure as the structural unit (II). [A] When the polymer has the structural unit (II), the adhesion of the resist film obtained from the radiation-sensitive resin composition is improved.

  Specific examples of the structural unit (II) include structural units represented by the following formulas (II-1) to (II-6).

In the formula (II-1) ~ (II -6), R 5 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R 6 is a hydrogen atom or a methyl group. R 7 is a hydrogen atom or a methoxy group. A is a single bond or a methylene group. B is a methylene group or an oxygen atom. a and b are each independently an integer of 0 to 2;

  As the structural unit (II), structural units represented by the following formulas (II-1a) to (II-6) are particularly preferable.

In the formulas (II-1a) to (II-6), the definition of R 5 is the same as the formulas (II-1) to (II-6).

  Among these, the structural unit represented by the above formula (II-5a) is particularly preferable from the viewpoint of excellent adhesion of the resulting resist pattern.

  [A] In the polymer, the content of the structural unit (II) is preferably from 0 to 70 mol%, more preferably from 20 to 65 mol%, based on all structural units constituting the [A] polymer. -60 mol% is more preferable. By making the content rate of structural unit (II) into the said range, the adhesiveness of the resist pattern obtained improves and pattern collapse tolerance can further be improved. [A] The polymer may contain one or more structural units (II) alone or in combination.

[Other structural units]
[A] The polymer may have a structural unit having a hydrophilic functional group (hereinafter also referred to as “structural unit (III)”). [A] Since the polymer has the structural unit (III), the polarity of the [A] polymer is increased in the resist film, and the compatibility with the highly polar [B] compound and [C] compound is improved. Then, by more preferably being dispersed, lithography performance such as MEEF of the obtained resist pattern can be further improved.

  As the structural unit (III), a structural unit represented by the following formula is preferable, and other structural units derived from acrylic acid or acrylic acid can be given.

In the above formula, R 8 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

  [A] In the polymer, the content of the structural unit (III) is preferably 0 to 30 mol%, more preferably 0 to 20 mol%, based on all structural units constituting the [A] polymer. [A] The polymer may contain one or more structural units (III) alone or in combination.

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

  In the radiation sensitive resin composition, the content of the polymer [A] is preferably 50% by mass or more, more preferably 60% by mass or more, based on the solid content, that is, the total amount of all components other than the solvent. 70 mass% or more is more preferable. The radiation-sensitive resin composition may contain one or more [A] polymers alone.

<[A] Polymer Synthesis Method>
[A] The polymer can be produced, for example, by polymerizing a monomer corresponding to each predetermined structural unit in a suitable solvent using a radical polymerization initiator.

  Examples of the radical polymerization initiator include 2,2′-azobis (2-methylpropionitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis ( 2-cyclopropylpropionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), azo radical initiators such as dimethyl 2,2′-azobisisobutyrate; benzoyl peroxide, t- Examples thereof include peroxide radical initiators such as butyl hydroperoxide and cumene hydroperoxide. Of these, AIBN and dimethyl 2,2'-azobisisobutyrate are preferred. These radical initiators can be used alone or in admixture 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;
Cycloalkanes 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, 2-butanone, 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. These solvents 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.

  [A] The weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer is preferably 1,500 to 100,000, more preferably 1,000 to 50,000, and 2,000. ˜30,000 is particularly preferred. [A] By making Mw of a polymer into the said range, lithography performances, such as MEEF of the said radiation sensitive resin composition, improve.

  [A] The ratio (Mw / Mn) between the polymer Mw and the polystyrene-equivalent number average molecular weight (Mn) by the GPC method is preferably 1 to 3, and more preferably 1 to 2. [A] By making Mw / Mn ratio of a polymer into the said range, lithography performances, such as MEEF of the said radiation sensitive resin composition, improve.

<[B] Compound>
The compound [B] generates sulfonic acid, carboxylic acid or sulfonamide upon irradiation with radiation, and at least one fluorine atom or perfluoro bonded to the α-position carbon atom of the sulfonic acid, carboxylic acid and sulfonamide. It is a compound having an alkyl group.
The radiation-sensitive resin composition contains a [B] compound that generates an acid upon exposure, so that a pattern can be formed by dissociating the acid-dissociable group of the [A] polymer. The performance of MEEF or the like can be exhibited at a high level by combining the sex group with the above specific structure and combining the [C] compound described later. The “α-position carbon atom” is adjacent to the functional group of the sulfonic acid, carboxylic acid or sulfonamide, that is, the —SO 2 — group of the sulfonic acid group and the sulfonamide group, or the C═O group of the carboxyl group. Refers to a carbon atom.

  The radiation is appropriately selected from visible rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams, etc., depending on the type of the [B] compound, and is ArF excimer laser (wavelength 193 nm) or KrF excimer. Far ultraviolet rays typified by a laser (wavelength 248 nm) are preferable, and an ArF excimer laser (wavelength 193 nm) is particularly preferable.

[B] The compound is not particularly limited as long as it has the above properties.
Examples of compounds that generate sulfonic acid include sulfonate salt compounds (such as onium salts), imide sulfonate compounds, oxime sulfonate compounds, diazomethane disulfone compounds, disulfone compounds, and the like;
Examples of compounds that generate carboxylic acid include carboxylate salt compounds (such as onium salts);
Examples of the compound that generates sulfonamide include sulfonamide salt compounds.

  [B] As the compound, a compound represented by the above formula (3) is preferable.

In the above formula (3), M + is a monovalent onium cation. X is a monovalent sulfonate anion, a carboxylate anion or a sulfonamide anion.

  [B] The compound is a compound represented by the above formula (3), that is, an onium sulfonate compound, an onium carboxylate compound or an onium sulfonamide compound, thereby improving the sensitivity of the radiation-sensitive resin composition. Can do.

  The onium sulfonate compound, onium carboxylate compound or onium sulfonamide compound represented by the above formula (3) is preferably a compound represented by the following formula (B1).

In the above formula (B1), Rf is a fluorine atom or a perfluoroalkyl group. R 9 and R 10 are each independently a hydrogen atom, a fluorine atom or a monovalent organic group. Part or all of the hydrogen atoms of this organic group may be substituted with a substituent. R 9 and R 10 may form a cyclic group together with the carbon atom to which each is bonded. G - is, SO 3 -, CO 2 - is a -R D - or SO 2 -N. RD is a monovalent organic group. M + is a monovalent onium cation.

  Examples of the perfluoroalkyl group represented by Rf include a trifluoromethyl group, a perfluoroethyl group, a perfluoro-n-propyl group, a perfluoro-i-propyl group, a perfluoro-n-butyl group, and a perfluoroalkyl group. A fluoro-i-butyl group, a perfluoro-sec-butyl group, a perfluoro-t-butyl group, a perfluoro-n-pentyl group, a perfluoro-n-hexyl group, and the like can be given.

Examples of the monovalent organic group represented by R 9 and R 10 include, for example, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and a carbon number that may have a fluorine atom. Examples thereof include an aryl group having 6 to 30 carbon atoms, an aralkyl group having 7 to 30 carbon atoms, and a heterocyclic group having 3 to 30 carbon atoms.

  Examples of the substituent that the alkyl group, cycloalkyl group, aryl group, aralkyl group, and heterocyclic group have include a hydroxyl group, a halogen atom, an alkoxy group, a lactone group, and an alkylcarbonyl group.

Examples of the cyclic group formed by R 9 and R 10 together with the carbon atoms to which they are bonded include a cycloalkanediyl group having 6 to 40 carbon atoms.

The above examples of the monovalent organic group represented by R D may be examples of the monovalent organic group represented by R 9 and R 10.

  As the compound represented by the formula (B1), compounds represented by the following formulas (Bi) to (B-iii) are preferable.

In the above formulas (Bi) to (B-iii),
Rf a1 to Rf a3 and Rf b1 to Rf b3 are each independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 4 carbon atoms. However, at least one of Rf a1 to Rf a3 and Rf b1 to Rf b3 bonded to the α-position carbon is a fluorine atom or a C 1 to C 4 perfluoroalkyl group. Z a , Z b and Z c are monovalent organic groups. q1-q3 is an integer of 1-10. R d is a monovalent organic group.

Examples of the monovalent organic group represented by Z a , Z b , Z c , and R d include the same groups as those exemplified for R 9 and R 10 in the formula (B-1). it can.

X in the above formula (3) is particularly preferably a monovalent sulfonate anion from the viewpoint of increasing the strength of the acid generated by irradiation and improving the performance of the resulting resist pattern such as MEEF.

As a specific example of the monovalent onium cation represented by M + in the above formula (3), for example,
Sulfonium cations such as triphenylsulfonium cation, 4-cyclohexylphenyldiphenylsulfonium cation, 4-methanesulfonylphenyldiphenylsulfonium cation, and sulfone group-containing triphenylsulfonium cation represented by the above formula (4);
Iodonium cations such as diphenyliodonium cation and bis (4-t-butylphenyl) iodonium cation;
1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium cation, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium cation, 1- (3,5-dimethyl-4 And tetrahydrothiophenium cations such as -hydroxyphenyl) tetrahydrothiophenium cation.

  Among these, from the viewpoint of improving the sensitivity of the radiation sensitive resin composition and the lithography performance such as MEEF, a sulfonium cation is preferable, and a triphenylsulfonium cation and a sulfone group-containing triphenylsulfonium represented by the above formula (S2) are preferred. A cation is more preferable, and a sulfone group-containing triphenylsulfonium cation represented by the above formula (S2) is more preferable.

  When the onium cation is a specific cation represented by the above formula (S2), the compatibility with the [A] polymer having an acid dissociable group is improved, and the dispersibility in the resist film is increased. Lithography performance such as MEEF of the radiation sensitive resin composition can be improved.

Sulfonium cation represented by the above formula (S2) has at least one -OSO 2 -R B2 or -SO 2 -R C2 as the substituent of the phenyl group.

R a2 , R b2 and R c2 in the above formula (S2) are each independently a hydroxyl group, a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, -S-R A2 , -OSO 2 -R B2 , or -SO 2 -R C2. R A2 is an alkyl group or an aryl group. R B2 and R C2 are each independently an alkyl group, a cycloalkyl group, an alkoxy group, or an aryl group. Some or all of the hydrogen atoms of the alkyl group, cycloalkyl group, alkoxy group and aryl group of R a2 , R b2 and R c2 and R A2 , R B2 and R C2 may be substituted. m2, n2 and p2 are each independently an integer of 0 to 5. However, m2 + n2 + p2 ≧ 1. If R a2, R b2 and R c2 are present in plural, the plurality of R a2, R b2 and R c2 may be the same as or different from each other. However, at least one of R a2 , R b2 and R c2 is —OSO 2 —RB 2 or —SO 2 —RC 2 .

Examples of the halogen atom represented by R a2 , R b2, and R c2 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group represented by R a2 , R b2 and R c2 is preferably an alkyl group having 1 to 8 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group.

The cycloalkyl group represented by R a2 , R b2 and R c2 is preferably a cycloalkyl group having 3 to 20 carbon atoms, and examples thereof include a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group. .

The alkoxy group represented by R a2 , R b2 and R c2 is preferably an alkoxy group having 1 to 8 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

The alkyl group represented by R A2 in the -S-R A2, preferably an alkyl group having 1 to 8 carbon atoms, such as methyl group, ethyl group, propyl group and a butyl group.

The aryl group represented by R A2 in the -S-R A2, preferably an aryl group having 6 to 20 carbon atoms, for example, a phenyl group, a naphthyl group, and the like.

Alkyl group represented by R C2 in R B2 and -SO 2 -R C2 in the -OSO 2 -R B2, examples of the cycloalkyl group and alkoxy groups, these in the R a2, R b2 and R c2 Examples of groups can be given. Further, examples of the aryl group represented by R B2 and R C2, preferably an aryl group having 6 to 20 carbon atoms, for example, a phenyl group, a naphthyl group, and the like.

Examples of the substituent in the alkyl group, cycloalkyl group, alkoxy group and aryl group of R a2 , R b2 and R c2 and R A2 , R B2 and R C2 include a hydroxyl group, a halogen atom, an alkoxy group and an alkoxycarbonyl group. Group, alkoxycarbonyloxy group and the like.

  Specific examples of the sulfone group-containing triphenylsulfonium cation represented by the above formula (S2) include cations represented by the following formula.

  Specific examples of the onium sulfonate compound represented by the above formula (B1) include compounds represented by the following formula.

In the above formula, M + is a monovalent onium cation. Examples of M +, can examples of M + in the formula (B1).

  Among them, a compound containing an anion having two fluorine atoms at the α-position carbon atom of the sulfonate group is preferable from the viewpoint of high acid strength of the generated sulfonic acid and high lithography performance such as MEEF. A compound containing an anion having 3 to 4 fluorine atoms in carbon atoms at the α-position and β-position (1-position and 2-position) is more preferred, and a compound containing a perfluoroalkylsulfonate anion is particularly preferred. Moreover, the compound containing the sulfonate anion which has polycyclic groups, such as an adamantyl group and a norbornyl group, from the viewpoint that compatibility with [A] polymer becomes high and performance, such as MEEF, becomes high is also preferable.

  Specific examples of the onium carboxylate compound represented by the above formula (B1) include compounds represented by the following formula.

In the above formula, M + is a monovalent onium cation. Examples of M +, can examples of M + in the formula (B1).

  Specific examples of the onium sulfonamide compound represented by the above formula (B1) include compounds represented by the following formula.

In the above formula, M + is a monovalent onium cation. Examples of M +, can examples of M + in the formula (B1).

  In the radiation sensitive resin composition, the content of the [B] compound is preferably 0.1 parts by mass or more and 20 parts by mass or less, and preferably 1 part by mass or more and 17 parts by mass with respect to 100 parts by mass of the [A] polymer. Part or less is more preferable. If the content of the [B] compound is less than the above lower limit, the sensitivity of the radiation sensitive resin composition may be lowered. Conversely, when the content of the [B] compound exceeds the above upper limit, the lithography performance such as MEEF of the resulting resist pattern tends to be lowered. These [B] compounds may be used individually by 1 type, and may use 2 or more types together.

<[C] Compound>
The compound [C] generates sulfonic acid, carboxylic acid or sulfonamide upon irradiation with radiation, and a fluorine atom and a perfluoroalkyl group are bonded to the α-position carbon atom of the sulfonic acid, carboxylic acid and sulfonamide. It is a compound that has not. The radiation-sensitive resin composition contains the [C] compound, so that the acid strength adjusting function in the exposed part, the high acid capturing function in the unexposed part, and the high acid by deactivation of this function in the exposed part. By exhibiting the diffusion control function, the MEEF performance, the LWR performance, and the pattern collapse resistance can be exhibited at a high level.

[C] The compound is not particularly limited as long as it has the above properties.
Examples of compounds that generate sulfonic acid include sulfonate salt compounds, imide sulfonate compounds, oxime sulfonate compounds, o-nitrobenzyl sulfonate compounds, diazomethane disulfone compounds, disulfone compounds, and the like;
Examples of compounds that generate carboxylic acid include carboxylate salt compounds, carboxylate imidocarboxylate compounds, o-nitrobenzyl carboxylate compounds, and the like;
Examples of the compound that generates sulfonamide include sulfonamide salt compounds.

  As the compound [C], a compound represented by the above formula (2) is preferable.

In the above formula (2), Q + is a monovalent onium cation. Y is a monovalent carboxylate anion, sulfonate anion or sulfonamide anion.

  [C] The compound is a compound represented by the above formula (2), that is, an onium carboxylate compound, an onium sulfonate compound, or an onium sulfonamide compound, so that high acid capture by anions in an unexposed area. In the exposed area, the acid trapping function is sufficiently eliminated due to high sensitivity, so that a more advanced acid diffusion control function is exhibited. As a result, MEEF performance, LWR performance, and pattern collapse resistance can be further improved.

  The onium carboxylate compound, onium sulfonate compound, or onium sulfonamide compound represented by the above formula (2) is preferably a compound represented by the following formula (C1).

In the above formula (C1), R 11 , R 12 and R 13 are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a monovalent organic group. Part or all of the hydrogen atoms of the organic group may be substituted with a substituent. Two or three of R 11 , R 12 and R 13 may form a cyclic group together with the carbon atom to which each is bonded. E is SO 3 , CO 2 or SO 2 —N —R E. R E is a monovalent organic group. Q + is a monovalent onium cation.

Examples of the halogen atom other than the fluorine atom represented by R 11 , R 12 and R 13 include a chlorine atom, a bromine atom and an iodine atom.

Examples of the monovalent organic group represented by R 11 , R 12 and R 13 and the substituent thereof include the monovalent organic group represented by R 9 and R 10 in the formula (B1) and the substitution thereof. Examples of groups can be given.

Examples of the cyclic group formed by two of R 11 , R 12 and R 13 together with the carbon atom to which each is bonded include, for example, a cycloalkanediyl group, and 3 of R 11 , R 12 and R 13 Examples of the cyclic group formed together with the carbon atoms to which they are bonded include, for example, a polycyclic aliphatic group such as a bicyclo [2.2.2] octanyl group and an adamantyl group, and an aromatic group such as a phenyl group and a naphthyl group. Etc.

The above examples of the monovalent organic group represented by R E may be examples of the monovalent organic group represented by R 11, R 12 and R 13.

Y in the above formula (2) is preferably a monovalent carboxylate anion or a sulfonamide anion, and more preferably a monovalent carboxylate anion. When the above Y is such an anion, the acid generated in the exposed area by irradiation is relatively low, so that the acid dissociable group of the polymer [A] is hardly dissociated, while the unexposed area 1 has a function of appropriately capturing the acid diffused from the exposed portion. As a result, due to the synergistic effect with the [A] polymer and the [B] compound, the lithography performance such as MEEF of the resist pattern obtained by the radiation-sensitive resin composition is further improved.

As an example of the monovalent onium cation represented by the above Q + , an example of the monovalent onium cation represented by M + of the formula (3) in the above-described [B] compound can be given. Among these, from the viewpoint of improving the sensitivity of the radiation sensitive resin composition and the lithography performance such as MEEF, a sulfonium cation is preferable, and the triphenylsulfonium cation and the sulfone group-containing triphenylsulfonium represented by the above formula (S1) are preferred. A cation is more preferable, and a sulfone group-containing triphenylsulfonium cation represented by the above formula (S1) is more preferable.

  Since the onium cation is a specific cation represented by the formula (S1), the compatibility with the [A] polymer having an acid dissociable group is improved, and the dispersibility in the resist film is increased. Lithographic performance such as MEEF of the radiation sensitive resin composition can be improved. The description of the sulfonium cation represented by the above formula (S1) is the same as the sulfonium cation represented by the above formula (S2) in the above-described [B] compound.

  In the radiation sensitive resin composition, when both the [B] compound and the [C] compound are onium salts, the onium cation of the [B] compound is a cation represented by the above formula (S1), and [ C] The onium cation of the compound is more preferably a cation represented by the above formula (S2). By making both the onium cations of the [B] compound and the [C] compound the above-mentioned specific cation, the compatibility between these ionic compounds and the [A] polymer having an acid dissociable group is further improved, Dispersibility in the resist film is further increased, and lithography performance such as MEEF of the radiation-sensitive resin composition is further improved.

  Specific examples of the onium sulfonate compound represented by the above formula (C1) include compounds represented by the following formula.

In the above formula, Q + is a monovalent onium cation.

  Specific examples of the onium carboxylate compound represented by the above formula (C1) include compounds represented by the following formula.

In the above formula, Q + is a monovalent onium cation.

  Among these, in the unexposed part, it has an appropriate capturing power for the acid generated in the exposed part, and the lithography performance such as MEEF of the resist pattern obtained from the radiation-sensitive resin composition is improved. A compound containing a carboxylate anion is preferred, and a compound containing a salicylate anion is particularly preferred.

  Specific examples of the onium sulfonamide compound represented by the above formula (C1) include compounds represented by the following formula.

In the above formula, Q + is a monovalent onium cation. Examples of Q +, can examples of Q + in the formula (2).

  Among these, since it is excellent in compatibility with the [A] polymer and the lithography performance such as MEEF of the resulting resist pattern is improved, an optionally substituted polycyclic group such as adamantyl group, norbornyl group, Or the compound containing the anion which has a lactone group is preferable.

  In the radiation sensitive resin composition, the [B] compound is a compound represented by the above formula (3), and the [C] compound is a compound represented by the above formula (2). It is particularly preferable that both the [B] compound and the [C] compound are compounds containing an onium cation. Both the [B] component and the [C] component are onium compounds, thereby obtaining a radiation-sensitive resin composition that is excellent in sensitivity and can exhibit MEEF performance, LWR performance, and pattern collapse resistance at a high level. be able to.

  [C] As described above, in addition to the onium salt compound, the compound [C] generates a sulfonic acid such as an imide sulfonate compound, an oxime sulfonate compound, an o-nitrobenzyl sulfonate compound, a diazomethane disulfone compound, and a disulfone compound; A compound that generates a carboxylic acid such as a carboxylate imidocarboxylate compound or an o-nitrobenzylcarboxylate compound can be used.

  In the radiation sensitive resin composition, the content of the [C] compound is preferably 0.1 part by mass or more and 20 parts by mass or less, and preferably 1 part by mass or more and 17 parts by mass with respect to 100 parts by mass of the [A] polymer. Part or less is more preferable. When the content of the [C] compound is less than the above lower limit, the performance of the obtained resist pattern such as MEEF tends to decrease. Conversely, when the content of the [C] compound exceeds the above upper limit, the sensitivity of the radiation sensitive resin composition may be reduced. These [C] compounds may be used individually by 1 type, and may use 2 or more types together.

  In the said radiation sensitive resin composition, as mass ratio of the usage-amount of the [C] compound with respect to the usage-amount of a [B] compound, 0.1-10 is preferable, 0.2-5 is more preferable, 0 More preferably, it is 3 or more and 3 or less. By making the said usage-amount ratio into the said range, the MEEF performance and LWR performance of the said radiation sensitive resin composition can be improved.

<Optional component>
In addition to the [A] polymer, the [B] compound and the [C] compound, the radiation-sensitive resin composition includes, as an optional component, a fluorine atom-containing polymer, an acid diffusion control, as long as the effects of the present invention are not impaired. Body, solvent, additive, surfactant, alicyclic skeleton-containing compound, sensitizer and the like.

[Fluorine atom-containing polymer]
The radiation-sensitive resin composition may contain a fluorine atom-containing polymer (excluding the [A] polymer). When the radiation-sensitive resin composition contains a fluorine atom-containing polymer, when the resist film is formed, the distribution is near the resist film surface due to the oil-repellent characteristics of the fluorine atom-containing polymer in the film. Therefore, it is possible to prevent the acid generator, the acid diffusion control agent, and the like from being eluted into the immersion medium during immersion exposure.

The fluorine-containing polymer is not particularly limited as long as it has a fluorine atom, but the fluorine atom content (mass%) is preferably higher than that of the [A] polymer. [A] When the fluorine atom content is higher than that of the polymer, the degree of uneven distribution described above becomes higher, and characteristics such as water repellency and elution suppression of the resulting resist film are improved. In addition, the fluorine atom content rate of the said fluorine-containing polymer and [A] polymer can be measured by < 13 > C-NMR.

  The fluorine-containing polymer preferably has a fluorinated alkyl group. When the fluorine atom-containing polymer has a fluorinated alkyl group in the structure, properties such as water breakage of the resulting resist film are further improved.

  The fluorine atom-containing polymer preferably has a structural unit (F-I) represented by the following formula (F1) and / or a structural unit (F-II) represented by the formula (F2). You may have "other structural units" other than FI) and structural unit (F-II). Hereinafter, each structural unit will be described in detail.

In the above formula (F1), R 14 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R 15 is a linear or branched alkyl group having 1 to 6 carbon atoms having at least a fluorine atom, or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms having at least a fluorine atom. However, in the alkyl group and alicyclic hydrocarbon group, part or all of the hydrogen atoms may be substituted.

In the formula (F2), R 16 is hydrogen atom, a fluorine atom a methyl group or a trifluoromethyl group. R 17 is a (r + 1) -valent linking group. X 1 is a divalent linking group having a fluorine atom. R 18 is a hydrogen atom or a monovalent organic group. r is an integer of 1 to 3. However, when r is 2 or 3, the plurality of X 1 and R 18 may be the same or different.

(Structural unit (FI))
The structural unit (FI) is a structural unit represented by the above formula (F1).

  Examples of the linear or branched alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an n-butyl group.

  Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include a cyclopentyl group, a cyclopentylpropyl group, a cyclohexyl group, a cyclohexylmethyl group, a cycloheptyl group, a cyclooctyl group, and a cyclooctylmethyl group.

  Examples of the monomer that gives the structural unit (FI) include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) acrylate, and perfluoro n-. Propyl (meth) acrylate, perfluoro i-propyl (meth) acrylate, perfluoro n-butyl (meth) acrylate, perfluoro i-butyl (meth) acrylate, perfluoro t-butyl (meth) acrylate, perfluorocyclohexyl ( (Meth) acrylate, 2- (1,1,1,3,3,3-hexafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) Pentyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) he Sil (meth) acrylate, perfluorocyclohexylmethyl (meth) acrylate, 1- (2,2,3,3,3-pentafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4) 4,4-Heptafluoro) penta (meth) acrylate, 1- (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10- Heptadecafluoro) decyl (meth) acrylate, 1- (5-trifluoromethyl-3,3,4,4,5,6,6,6-octafluoro) hexyl (meth) acrylate and the like.

  Examples of the structural unit (FI) include structural units represented by the following formulas (F1-1) and (F1-2).

In the formulas (F1-1) and (F1-2), the definition of R 14 is the same as the formula (F1).

  In the fluorine atom-containing polymer, the content of the structural unit (FI) is preferably 30 mol% to 100 mol% with respect to all the structural units constituting the fluorine atom-containing polymer. In addition, the fluorine atom containing polymer may have 1 type (s) or 2 or more types of structural units (FI).

(Structural unit (F-II))
The structural unit (F-II) is a structural unit represented by the above formula (F2).

In the above formula (F2), the (r + 1) -valent linking group represented by R 17 is, for example, a linear or branched hydrocarbon group having 1 to 30 carbon atoms or an alicyclic hydrocarbon having 3 to 30 carbon atoms. A group, an aromatic hydrocarbon group having 6 to 30 carbon atoms, or one or more groups selected from the group consisting of these groups and an oxygen atom, a sulfur atom, an ether group, an ester group, a carbonyl group, an imino group, and an amide group And a combination of these. The (r + 1) -valent linking group may have a substituent.

  Examples of the linear or branched hydrocarbon group having 1 to 30 carbon atoms include (r + 1) hydrocarbon groups such as methane, ethane, propane, butane, pentane, hexane, heptane, decane, icosane and triacontane. And a group in which a hydrogen atom is removed.

Examples of the alicyclic hydrocarbon group having 3 to 30 carbon atoms include monocyclic saturated hydrocarbons such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, methylcyclohexane, and ethylcyclohexane;
Monocyclic unsaturated hydrocarbons such as cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclodecene, cyclopentadiene, cyclohexadiene, cyclooctadiene, cyclodecadiene;
Bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, tricyclo [5.2.1.0 2,6 ] decane, tricyclo [3.3.1.1 3,7 ] decane, Tetracyclo [6.2.1.1 3,6 . 0 2,7 ] polycyclic saturated hydrocarbons such as dodecane and adamantane;
Bicyclo [2.2.1] heptene, bicyclo [2.2.2] octene, tricyclo [5.2.1.0 2,6 ] decene, tricyclo [3.3.1.1 3,7 ] decene, Tetracyclo [6.2.1.1 3,6 . And a group obtained by removing (r + 1) hydrogen atoms from a polycyclic hydrocarbon group such as 0 2,7 ] dodecene.

  Examples of the aromatic hydrocarbon group having 6 to 30 carbon atoms include (r + 1) from aromatic hydrocarbon groups such as benzene, naphthalene, phenanthrene, anthracene, tetracene, pentacene, pyrene, picene, toluene, xylene, ethylbenzene, mesitylene, cumene, and the like. ) Groups from which a single hydrogen atom has been removed.

In the above formula (F2), examples of the divalent linking group having a fluorine atom represented by X 1 include a C 1-20 divalent linear hydrocarbon group having a fluorine atom. Examples of X 1 include structures represented by the following formulas (X-1) to (X-6).

X 1 is preferably a structure represented by the above formulas (X-1) and (X-2).

In the above formula (F2), examples of the organic group represented by R 18 include a linear or branched hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, and 6 carbon atoms. To 30 aromatic hydrocarbon groups, or a combination of these groups and one or more groups selected from the group consisting of oxygen, sulfur, ether, ester, carbonyl, imino and amide groups Is mentioned.

In the formula (F2), when R 18 is a hydrogen atom, it is preferable in that the solubility of the fluorine atom-containing polymer in the developer can be improved.

  Examples of the structural unit (F-II) include structural units represented by the following formulas (F2-1) and (F2-2).

In the above formula (F2-1), R 17 is a divalent linear, branched or cyclic hydrocarbon group of saturated Wakashi Ku unsaturated having 1 to 20 carbon atoms. R 16 , X 1 and R 18 have the same meaning as in the above formula (F2).
In the formula (F2-2), R 16 , X 1 , R 18 and r are as defined in the above formula (F2). However, when r is 2 or 3, the plurality of X 1 and R 18 may be the same or different.

  As the structural unit represented by the above formula (F2-1) and formula (F2-2), for example, the following formula (F2-1-1), formula (F2-1-2) and formula (F2-2-1) The structural unit shown by these is mentioned.

In the formulas (F2-1-1), (F2-1-2), and (F2-2-1), R 16 has the same meaning as the formula (F2).

  Examples of the monomer that gives the structural unit (F-II) include (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-3-propyl) ester, (meth) Acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2 -Hydroxy-5-pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester, (meth) acrylic acid 2-{[5 -(1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl] bicyclo [2.2.1] heptyl} ester and the like.

  As a content rate of the fluorine atom containing polymer in the said radiation sensitive resin composition, 0-50 mass parts is preferable with respect to 100 mass parts of [A] polymers, 0-20 mass parts is more preferable, 1- 10 mass parts is further more preferable, and 2-8 mass parts is especially preferable. When the content of the fluorine atom-containing polymer in the radiation-sensitive resin composition is in the above range, the water repellency and elution suppression of the resulting resist film surface can be further enhanced.

[Acid diffusion controller]
The acid diffusion controller controls the diffusion phenomenon of the acid generated by exposure in the resist film and suppresses an undesirable chemical reaction in the non-exposed region, and the storage stability of the resulting radiation-sensitive resin composition is improved. In addition to further improving the resolution as a resist, it is possible to suppress changes in the line width of the resist pattern due to fluctuations in the holding time from exposure to development processing, resulting in a composition with extremely excellent process stability. It is done. The inclusion form of the acid diffusion controller in the composition may be in the form of a free compound, incorporated as part of the polymer, or both forms.

  Examples of the acid diffusion controller include amine compounds, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.

  Examples of the amine compound include mono (cyclo) alkylamines; di (cyclo) alkylamines; tri (cyclo) alkylamines; substituted alkylanilines or derivatives thereof; ethylenediamine, N, N, N ′, N′-tetra Methylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4 -Aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-amino) Phenyl) -2- (4-hydroxyphenyl) propane, 1, -Bis (1- (4-aminophenyl) -1-methylethyl) benzene, 1,3-bis (1- (4-aminophenyl) -1-methylethyl) benzene, bis (2-dimethylaminoethyl) ether Bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″ N ″ -pentamethyldiethylenetriamine and the like.

  Examples of amide group-containing compounds include Nt-butoxycarbonyl group-containing amino compounds, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, Examples thereof include benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, and isocyanuric acid tris (2-hydroxyethyl).

  Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea and the like. Is mentioned.

  Examples of the nitrogen-containing heterocyclic compound include imidazoles; pyridines; piperazines; pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4- Methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3- (N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2 ] Octane etc. are mentioned.

  These acid diffusion inhibitors may be used alone or in combination of two or more. The content of the acid diffusion controller is preferably less than 15 parts by mass and more preferably less than 10 parts by mass with respect to 100 parts by mass of the [A] polymer. When the usage-amount of an acid diffusion control body exceeds 15 mass parts, it exists in the tendency for the sensitivity as a resist to fall.

[solvent]
The radiation sensitive resin composition usually contains a solvent. The solvent to be used is not particularly limited as long as it is a solvent capable of dissolving at least the [A] polymer, the [B] compound and the [C] compound, and an optional component optionally contained. Examples of such solvents include alcohols, ethers, diethylene glycol alkyl ethers, ethylene glycol alkyl ether acetates, propylene glycol monoalkyl ethers, propylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ether propionates, Aromatic hydrocarbons, ketones, esters / lactones, amides, nitriles and mixed solvents thereof can be used.

These solvents include
Examples of alcohols include benzyl alcohol and diacetone alcohol;
Examples of ethers include dialkyl ethers such as tetrahydrofuran, diisopropyl ether, di n-butyl ether, di n-pentyl ether, diisopentyl ether, and di n-hexyl ether;
Examples of diethylene glycol alkyl ethers include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol ethyl methyl ether;
Examples of ethylene glycol alkyl ether acetates include methyl cellosolve acetate, ethyl cellosolve acetate, ethylene glycol monobutyl ether acetate, and ethylene glycol monoethyl ether acetate;
Examples of propylene glycol monoalkyl ethers include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether;
Examples of propylene glycol monoalkyl ether acetates include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and propylene glycol monobutyl ether acetate;
Examples of propylene glycol monoalkyl ether propionates include propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether propionate, propylene glycol monopropyl ether propionate, propylene glycol monobutyl ether propionate and the like;

Examples of aromatic hydrocarbons include toluene and xylene;
Examples of ketones include methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 2-heptanone, 4-hydroxy-4-methyl-2-pentanone, etc.
Examples of esters include methyl acetate, ethyl acetate, propyl acetate, i-propyl acetate, butyl acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, 2-hydroxy-2-methylpropionic acid Ethyl, methyl hydroxyacetate, ethyl hydroxyacetate, butyl hydroxyacetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, protyl 3-hydroxypropionate, 3-hydroxy Butyl propionate, methyl 2-hydroxy-3-methylbutanoate, methyl methoxyacetate, ethyl methoxyacetate, propyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate, ethoxy Butyl acetate, methyl propoxyacetate, ethyl propoxyacetate, propylpropoxyacetate, butyl propoxyacetate, methyl butoxyacetate, ethyl butoxyacetate, propylbutoxyacetate, butylbutoxyacetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, 2 -Propyl methoxypropionate, butyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate and the like;
Examples of amides include formamide, N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like;
Examples of nitriles include acetonitrile and propionitrile, respectively.

  Among these, it is preferable to use propylene glycol monoalkyl ether acetates, particularly propylene glycol monomethyl ether acetate. In addition, propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, ketones such as cyclohexanone, esters such as alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, and ethyl lactate are preferable. These solvent can be used individually by 1 type or in mixture of 2 or more types.

[Additive]
The said radiation sensitive resin composition can contain the additive which has the effect of segregating the said fluorine-containing polymer on the resist film surface more efficiently. By adding this additive to the radiation-sensitive resin composition, the amount of the fluorine-containing polymer added can be reduced as compared with the conventional case. Therefore, the elution of the components from the resist film to the immersion liquid is further suppressed, and the immersion exposure is performed at a higher speed without damaging the basic resist characteristics such as MEEF performance, LWR performance, and pattern collapse resistance. Examples of such additives include lactone compounds such as γ-butyrolactone, cyclic carbonate compounds such as propylene carbonate, nitrile compounds such as succinonitrile, polyhydric alcohols such as glycerin, and the like. Can be mentioned.

[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. In addition to nonionic surfactants such as stearate, the following trade names are KP341 (Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, Kyoeisha Chemical Co., Ltd.), F-Top EF301, EF303, EF352 (above, Tochem Products), MegaFuck F171, F173 (above, Dainippon Ink and Chemicals), Florard FC430, FC431 ( Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (above, Asahi Glass Industry) Company). These surfactants may be used alone or in combination of two or more.

[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.

Examples of the alicyclic skeleton-containing compound include adamantane derivatives such as 1-adamantanecarboxylic acid, 2-adamantanone, and 1-adamantanecarboxylic acid t-butyl;
Deoxycholic acid esters such as t-butyl deoxycholate, t-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid;
Lithocholic acid esters such as t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid;
3- [2-Hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 2,5 . 1 7,10 ] dodecane, 2-hydroxy-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 3,7 ] nonane, and the like. These alicyclic skeleton containing compounds may be used independently and may use 2 or more types together.

[Sensitizer]
The sensitizer exhibits an action of increasing the amount of acid generated from the [B] compound and / or the [C] compound, and has an effect of improving the “apparent sensitivity” of the 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.

<Preparation of radiation-sensitive resin composition>
The composition can be prepared, for example, by mixing the [A] polymer, the [B] compound, the [C] compound, and an arbitrary component in a predetermined ratio in an organic solvent. Moreover, the said radiation sensitive resin composition can be prepared and used in the state melt | dissolved or disperse | distributed to the appropriate organic solvent.

<Method for forming photoresist pattern>
The radiation sensitive resin composition of the present invention is useful as a chemically amplified resist. In a chemically amplified resist, an acid-dissociable group such as the [A] polymer is dissociated by the action of an acid generated by exposure to generate a polar group typified by a carboxyl group. As a result, the solubility of the exposed portion of the resist in the alkaline developer is increased, and the exposed portion is dissolved and removed by the alkaline developer to obtain a positive photoresist pattern. In addition, by using a relatively low-polarity developer containing an organic solvent or the like as a developing solution, a portion of the polar group generated by the exposure is hardly soluble in the developing solution, thereby obtaining a negative photoresist pattern. It is done.

  Hereinafter, a method for forming a photoresist pattern using the radiation-sensitive resin composition will be described in detail.

The pattern forming method of the present invention comprises:
(1) The process of forming a coating film on a board | substrate using the said radiation sensitive resin composition,
(2) A step of irradiating at least a part of the coating film with radiation,
(3) a step of heating the coating film irradiated with the radiation; and (4) a step of developing the heated coating film. Hereinafter, each step will be described.

  In the step (1), a radiation sensitive resin composition or a composition solution obtained by dissolving it in a solvent is applied to a substrate (silicon wafer) by an appropriate application means such as spin coating, cast coating, roll coating or the like. , Silicon dioxide, a wafer coated with an antireflection film, etc.) to form a photoresist film. Specifically, after applying the resin composition solution so that the obtained resist film has a predetermined film thickness, the solvent in the coating film is vaporized by pre-baking (PB) to form a resist film.

  In step (2), the photoresist film formed in step (1) is irradiated with radiation (possibly through an immersion medium such as water) and exposed. In this case, radiation is irradiated through a mask having a predetermined pattern. As the radiation, irradiation is performed by appropriately selecting from visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams and the like according to the line width of the target pattern. Among these, far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm) and KrF excimer laser (wavelength 248 nm) are preferable, and ArF excimer laser is particularly preferable.

  Step (3) is called post-exposure bake (PEB), and is a step of promoting deprotection of the polymer by the acid generated by exposure in the exposed portion of the photoresist film in step (2). This PEB causes a difference in solubility in an alkaline developer between an exposed portion (exposed portion) and an unexposed portion (unexposed portion). PEB is usually carried out by appropriately selecting in the range of 50 ° C to 180 ° C.

  In step (4), the exposed photoresist film is developed with a developer to form a predetermined photoresist pattern. After development, it is common to wash with water and dry. As the developer, for example, 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-diazabicyclo- [4.3. 0] An aqueous alkaline solution in which at least one of alkaline compounds such as 5-nonene is dissolved is preferable. Further, as described above, as the developer, an organic solvent such as a hydrocarbon solvent, an ether solvent, an ester solvent, a ketone solvent, an alcohol solvent, or a solvent containing an organic solvent can be used.

  Also, when performing immersion exposure, before the step (2), in order to protect the direct contact between the immersion liquid and the resist film, an immersion liquid insoluble immersion protective film is formed on the resist film. It may be provided. As a protective film for immersion, a solvent peeling type protective film (see, for example, Japanese Patent Application Laid-Open No. 2006-227632) that peels off with a solvent before the step (4), a development that peels off simultaneously with the development in the step (4) Any of liquid-removable protective films (see, for example, WO2005-069096 and WO2006-035790) may be used. However, from the viewpoint of throughput, it is preferable to use a developer peeling type immersion protective film.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail 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) and number average molecular weight (Mn)]
Mw and Mn of the polymer were measured by gel permeation chromatography (GPC) using Tosoh's GPC columns ("G2000HXL", "G3000HXL", "G4000HXL") under the following conditions: It was measured by.
Eluent: Tetrahydrofuran (Wako Pure Chemical Industries)
Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

[ 13 C-NMR analysis]:
The content rate (mol%) of the structural unit of the polymer synthesized below and the fluorine atom content rate (mass%) of the fluorine-containing polymer are “JNM-EX400” manufactured by JEOL Ltd., and DMSO-d as a measurement solvent. 6 was measured.

<[A] Synthesis of polymer>
In the following synthesis examples, the polymers (A-1) to (A-3) and (a-1) and (a-2) are respectively represented by the following formulas (S-1) to (S-6). The compound was synthesized using a compound (hereinafter sometimes referred to as “compound (S-1)”).

[Synthesis Example 1]
(Synthesis of polymer (A-1))
41.28 g (50 mol%) of the above compound (S-1) and 58.74 g (50 mol%) of the above compound (S-2) were dissolved in 200 g of 2-butanone, and 2,2′-azobis ( A monomer solution charged with 3.47 g of 2-methylpropionitrile was prepared. A 1,000 mL three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reactor was heated to 80 ° C. with stirring, and the monomer solution prepared above was added to the dropping funnel. And added dropwise over 3 hours. The polymerization reaction was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization reaction solution was cooled with water to 30 ° C. or less, poured into 4,000 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was dispersed in 400 g of methanol to form a slurry and then filtered and washed twice, and then vacuum dried at 50 ° C. for 17 hours to obtain a white powder polymer (A- 1) was obtained (73 g, yield 73%). This polymer (A-1) has Mw of 5,300 and Mw / Mn = 1.40. As a result of 13 C-NMR analysis, the polymer (A-1) is derived from the compound (S-1) and the compound (S-2), respectively. The content of the structural unit was 47.6: 52.4 (mol%).

[Synthesis Example 2]
(Synthesis of polymer (A-2))
43.38 g (50 mol%) of the above compound (S-3) and 56.60 g (50 mol%) of the above compound (S-2) are dissolved in 200 g of 2-butanone, and 2,2′-azobis ( A monomer solution charged with 3.35 g of 2-methylpropionitrile was prepared. A 1,000 mL three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reactor was heated to 80 ° C. with stirring, and the monomer solution prepared above was added to the dropping funnel. And added dropwise over 3 hours. The polymerization reaction was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization reaction solution was cooled with water to 30 ° C. or less, poured into 4,000 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was dispersed in 400 g of methanol to form a slurry, and then washed twice by filtration, and then vacuum dried at 50 ° C. for 17 hours to obtain a white powder polymer (A-2 (72 g, yield 72%). This polymer (A-2) has Mw of 5,000 and Mw / Mn = 1.43, and as a result of 13 C-NMR analysis, it is derived from the compound (S-3) and the compound (S-2), respectively. The content of the structural unit was 46.6: 53.4 (mol%).

[Synthesis Example 3]
(Synthesis of polymer (A-3))
48.86 g (50 mol%) of the compound (S-5) and 51.14 g (50 mol%) of the compound (S-2) were dissolved in 200 g of 2-butanone, and 2,2′-azobis ( A monomer solution charged with 3.02 g of 2-methylpropionitrile was prepared. A 1,000 mL three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reactor was heated to 80 ° C. with stirring, and the monomer solution prepared above was added to the dropping funnel. And added dropwise over 3 hours. The polymerization reaction was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization reaction solution was cooled with water to 30 ° C. or less, poured into 4,000 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was dispersed in 400 g of methanol to form a slurry and then filtered and washed twice, and then vacuum dried at 50 ° C. for 17 hours to obtain a white powder polymer (A-3 ) Was obtained (70 g, yield 70%). This polymer (A-3) has Mw of 6,000 and Mw / Mn = 1.83, and as a result of 13 C-NMR analysis, the polymer (A-3) is derived from the compound (S-5) and the compound (S-2), respectively. This was a copolymer having a content of structural units of 45.2: 54.8 (mol%).

[Synthesis Example 4]
(Synthesis of polymer (a-1))
39.06 g (50 mol%) of the compound (S-4) and 60.98 g (50 mol%) of the compound (S-2) were dissolved in 200 g of 2-butanone, and 2,2′-azobis ( A monomer solution charged with 3.61 g of 2-methylpropionitrile was prepared. A 1,000 mL three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reactor was heated to 80 ° C. with stirring, and the monomer solution prepared above was added to the dropping funnel. And added dropwise over 3 hours. The polymerization reaction was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization reaction solution was cooled with water to 30 ° C. or less, poured into 4,000 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was dispersed in 400 g of methanol to form a slurry, and then washed twice by filtration, and then vacuum dried at 50 ° C. for 17 hours to obtain a white powder polymer (a-1 ) Was obtained (75 g, yield 75%). This polymer (a-1) has Mw of 5,000 and Mw / Mn = 1.43, and as a result of 13 C-NMR analysis, the polymer (a-1) is derived from the compound (S-4) and the compound (S-2), respectively. The content of the structural unit was 46.6: 53.4 (mol%).
[Synthesis Example 5]
(Synthesis of polymer (a-2))
57.16 g (50 mol%) of the compound (S-6) and 42.84 g (50 mol%) of the compound (S-2) were dissolved in 200 g of 2-butanone, and 2,2′-azobis ( A monomer solution charged with 2.53 g of 2-methylpropionitrile was prepared. A 1,000 mL three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reactor was heated to 80 ° C. with stirring, and the monomer solution prepared above was added to the dropping funnel. And added dropwise over 3 hours. The polymerization reaction was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization reaction solution was cooled with water to 30 ° C. or less, poured into 4,000 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was dispersed in 400 g of methanol to form a slurry, and then washed twice by filtration, and then vacuum-dried at 50 ° C. for 17 hours to obtain a white powder polymer (a-2 ) Was obtained (68 g, yield 68%). This polymer (a-2) has Mw of 6,600 and Mw / Mn = 1.89, and as a result of 13 C-NMR analysis, it was derived from the compound (S-6) and the compound (S-2), respectively. This was a copolymer having a content of structural units of 43.2: 56.8 (mol%).

<[D] Synthesis of fluorine atom-containing polymer>
[Synthesis Example 6]
(Synthesis of fluorine atom-containing polymer (D-1))
The following compound (S-7) 37.41 g (40 mol%) and the following compound (S-8) 62.59 g (60 mol%) were dissolved in 2-butanone 100 g, and 2,2′-azobis (2 -A monomer solution charged with 4.79 g of methylpropionitrile) was prepared. A 1,000 mL three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared above was added using a dropping funnel. The solution was added dropwise over 3 hours. The polymerization reaction was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, 150 g of 2-butanone was removed from the polymerization reaction solution under reduced pressure. After cooling to 30 ° C. or lower, the mixture was poured into a mixed solvent of 900 g of methanol and 100 g of ultrapure water, and the precipitated white powder was filtered off. The filtered white powder was dispersed in 100 g of methanol and washed in the form of a slurry, and then the same washing operation with methanol was performed twice. The obtained white powder was vacuum-dried at 50 ° C. for 17 hours to obtain a fluorine-containing polymer (D-1) (78 g, yield 78%). This copolymer has Mw of 6,920 and Mw / Mn = 1.582, and as a result of 13 C-NMR analysis, structural units derived from the compound (S-7) and the compound (S-8), respectively. The content ratio was 40.8: 59.2 (mol%). The fluorine atom content was 9.6% by mass.

<Preparation of radiation-sensitive resin composition>
Polymers (A-1), (A-2), (A-3), (a-1) and (a-2) synthesized in the above synthesis examples, and a fluorine atom-containing polymer (D-1) Each component ([B] compound, [C] compound, [E] acid diffusion controlling agent, [F] solvent and [G] additive, which constitute the radiation sensitive resin composition other than the above, is shown.

([B] compound)
(B-1) Triphenylsulfonium 4-adamantylcarbonyloxy-1,1,2,2-tetrafluorobutane-1-sulfonate (compound represented by the following formula (B-1))
(B-2) 4-cyclohexylsulfonylphenyldiphenylsulfonium 4-adamantylcarbonyloxy-1,1,2,2-tetrafluorobutane-1-sulfonate (compound represented by the following formula (B-2))

([C] compound)
(C-1) Tetraphenylsulfonium salicylate (compound represented by the following formula (C-1))
(C-2) 4-cyclohexylsulfonylphenyldiphenylsulfonium salicylate (compound represented by the following formula (C-2))

[E] Acid diffusion controller (E-1) tert-butyl 4-hydroxy-1-piperidinecarboxylate (compound represented by the following formula (E-1))

[F] Solvent (F-1) Propylene glycol monomethyl ether acetate (F-2) Cyclohexanone

[G] Additive (G-1) γ-Butyrolactone

[Example 1]
[A] 100 parts by mass of the polymer (A-1) as the polymer, 13 parts by mass of the compound (B-1) as the [B] compound, 13 parts by mass of the compound (C-1) as the [C] compound, [D] 3 parts by mass of the polymer (D-1) as the fluorine-containing polymer, 1980 parts by mass of the solvent (F-1) and 848 parts by mass of the solvent (F-2) as the [F] solvent, [G] After adding 200 parts of the compound (G-1) as an additive, each was mixed to obtain a uniform solution. Then, the radiation sensitive resin composition (J-1) of Example 1 was prepared by filtering using a membrane filter with a pore diameter of 200 nm. The total solid concentration in the radiation-sensitive resin composition (J-1), that is, the concentration of components other than the [F] solvent relative to the entire composition was about 4% by mass.

[Examples 2 to 5 and Comparative Examples 1 to 5]
In Example 1, the radiation sensitive resin compositions of the Examples and Comparative Examples were prepared in the same manner as in Example 1 except that the types and blending amounts (parts by mass) of the components were as shown in Table 1. .

<Evaluation>
About the obtained radiation sensitive resin composition, the resist pattern was formed using the pattern formation method shown below, and MEEF, LWR, and pattern collapse tolerance of the obtained pattern were evaluated by the following method. In addition, as a pattern formation method used for evaluation, Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 use the following pattern formation method (P-1), Examples 4 and 5, and Comparative Examples For 4 and 5, the following pattern formation method (P-2) was used. The obtained evaluation results are shown in Table 2.

[Method of forming pattern to be evaluated]
(Pattern formation method (P-1))
On the 12-inch silicon wafer on which the lower antireflection film (“ARC66”, manufactured by Nissan Chemical Industries, Ltd.) was formed, a film having a film thickness of 75 nm was formed from the prepared radiation sensitive resin composition, and the temperature shown in Table 2 was obtained. Pre-baking (PB) was performed for 60 seconds. Next, this film is exposed through a mask pattern using an ArF excimer laser immersion exposure apparatus (“NSR S610C”, manufactured by NIKON) under the conditions of NA = 1.3, ratio = 0.800, and annular. did. After exposure, post-exposure baking (PEB) was performed at the temperatures shown in Table 2 for 60 seconds. Then, it developed with 2.38 mass% tetramethylammonium hydroxide aqueous solution, washed with water, and dried, and the positive resist pattern (P-1) was formed.

(Pattern formation method (P-2))
On the 12-inch silicon wafer on which the lower antireflection film (“ARC66”, manufactured by Nissan Chemical Industries, Ltd.) was formed, a film having a film thickness of 75 nm was formed from the prepared radiation sensitive resin composition, and the temperature shown in Table 2 was obtained. PB was performed for 60 seconds. Next, on the formed film, the composition for forming an upper layer film described in paragraph [0138] of International Publication No. 2008/047678 is spin-coated, and PB is performed at 90 ° C. for 60 seconds so that the film thickness becomes 90 nm. A coating film was formed. This film was exposed through a mask pattern using an ArF excimer laser immersion exposure apparatus (“NSR S610C”, manufactured by NIKON) under the conditions of NA = 1.3, ratio = 0.800, and annular. After the exposure, PEB was performed at the temperature shown in Table 2 for 60 seconds. Thereafter, the resist film was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution, washed with water, and dried to form a positive resist pattern (P-2).

[MEEF]
In the above formation method, the exposure amount at which a line-and-space (LS) pattern with a line width of 50 nm is formed by exposure through a mask pattern with a target size of 50 nm 1 L / 1S was defined as the optimum exposure amount. Next, an LS pattern with a pitch of 100 nm is formed using a mask pattern with a line width target size of 46 nm, 48 nm, 50 nm, 52 nm, and 54 nm at this optimum exposure amount, and the line width formed on the resist film is scanned. Measurement was performed using a scanning electron microscope (“CG4000” manufactured by Hitachi, Ltd.). At this time, the slope of the straight line when the target size (nm) was plotted on the horizontal axis and the line width (nm) formed on the resist film using each mask pattern was plotted on the vertical axis was calculated as MEEF. MEEF indicates that the closer the value is to 1, the better the mask reproducibility.

[LWR]
In the above formation method, the exposure amount at which a resist pattern having a line width of 50 nm is formed by exposure through a mask pattern having a target size of 50 nm 1 L / 1.8 S was determined as the optimum exposure amount. The 50 nm 1L / 1.8S pattern obtained with this optimum exposure dose was observed from the top of the pattern using a scanning electron microscope (“CG4000” manufactured by Hitachi, Ltd.), and the line width was measured at 10 arbitrary points. The value representing the variation in the line width with 3 sigma was defined as LWR. It shows that the linearity of a pattern is excellent, so that the value of LWR is low.

[Pattern collapse resistance (minimum collapse dimension)]
In the above formation method, exposure was performed while changing the exposure amount by 1 mJ through a mask pattern having a target size of 50 nm 1 L / 1.8 S. The line width of the pattern formed with an exposure amount 1 mJ smaller than the exposure amount at which the line collapse occurred was measured with a scanning electron microscope (manufactured by Hitachi, Ltd., model number “CG4000”). did. It shows that the tolerance with respect to the fall of a pattern is so high that this value is small.

  From the above Examples and Comparative Examples, it was confirmed that by using the radiation sensitive resin composition of the present invention, the LWR performance and the minimum collapse dimension were improved and the balance with the MEEF performance was good.

  ADVANTAGE OF THE INVENTION According to this invention, the radiation sensitive resin composition which can exhibit MEEF performance, LWR performance, and pattern collapse tolerance at a high level can be provided.

Claims (8)

  1. [A] a polymer having a structural unit represented by the following formula (1):
    [B] Irradiation generates sulfonic acid, carboxylic acid or sulfonamide, and at least one fluorine atom or perfluoroalkyl group in which the sulfonic acid, carboxylic acid and sulfonamide are bonded to the α-position carbon atom. And a compound having [C] radiation to generate a sulfonic acid, a carboxylic acid or a sulfonamide, and a fluorine atom and a perfluoroalkyl group in which the sulfonic acid, carboxylic acid and sulfonamide are bonded to the α-position carbon atom. Contains compounds that do not have any,
    [C] The radiation sensitive resin composition in which the compound is represented by the following formula (2) .
    (In Formula (1), R 1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R 2 , R 3 and R 4 are each independently a straight chain having 1 to 10 carbon atoms. A branched or branched alkyl group, provided that R 2 , R 3 and R 4 are not all methyl groups.)
    (In Formula (2), Q + is a monovalent onium cation. Y is a monovalent carboxylate anion.)
  2. The radiation sensitive resin composition according to claim 1 , wherein Q + in the formula (2) is represented by the following formula (S1).
    (In formula (S1), R a1 , R b1 and R c1 each independently represent a hydroxyl group, a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, —S—R A1 , —OSO 2 —R B1. Or —SO 2 —R C1 , R A1 represents an alkyl group or an aryl group, and R B1 and R C1 each independently represents an alkyl group, a cycloalkyl group, an alkoxy group, or an aryl group. Some or all of the hydrogen atoms of the alkyl group, cycloalkyl group, alkoxy group and aryl group of R a1 , R b1 and R c1 and R A1 , R B1 and R C1 may be substituted. p1 is each independently an integer of 0 to 5, provided that m1 + n1 + p1 ≧ 1 When there are a plurality of R a1 , R b1 and R c1 , The plurality of R a1 , R b1 and R c1 may be the same or different, provided that at least one of R a1 , R b1 and R c1 is —OSO 2 —R B1 or —SO 2 —R. C1 .)
  3. The radiation sensitive resin composition of Claim 1 or Claim 2 with which a [B] compound is represented by following formula (3).
    (In Formula (3), M + is a monovalent onium cation. X is a monovalent sulfonate anion.)
  4. [A] a polymer having a structural unit represented by the following formula (1):
    [B] Irradiation generates sulfonic acid, carboxylic acid or sulfonamide, and at least one fluorine atom or perfluoroalkyl group in which the sulfonic acid, carboxylic acid and sulfonamide are bonded to the α-position carbon atom. A compound having, and
    [C] Upon irradiation with radiation, sulfonic acid, carboxylic acid or sulfonamide is generated, and the sulfonic acid, carboxylic acid and sulfonamide have both a fluorine atom and a perfluoroalkyl group bonded to the α-position carbon atom. No compound
    Containing
    [B] A radiation sensitive resin composition in which the compound is represented by the following formula (3).
    (In formula (1), R 1 Is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R 2 , R 3 And R 4 Are each independently a linear or branched alkyl group having 1 to 10 carbon atoms. However, R 2 , R 3 And R 4 Is not all methyl groups. )
    (In formula (3), M + Is an onium cation represented by the following formula (S2). X Is a monovalent sulfonate anion. )
    (In formula (S2), R a2 , R b2 And R c2 Each independently represents a hydroxyl group, a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, -SR A2 , -OSO 2 -R B2 Or -SO 2 -R C2 It is. R A2 Is an alkyl group or an aryl group. R B2 And R C2 Are each independently an alkyl group, a cycloalkyl group, an alkoxy group or an aryl group. R a2 , R b2 And R c2 And R A2 , R B2 And R C2 Some or all of the hydrogen atoms of the alkyl group, cycloalkyl group, alkoxy group, and aryl group of may be substituted. m2, n2 and p2 are each independently an integer of 0 to 5. However, m2 + n2 + p2 ≧ 1. R a2 , R b2 And R c2 When there are a plurality of each, a plurality of R a2 , R b2 And R c2 May be the same or different. However, R a2 , R b2 And R c2 At least one of -OSO 2 -R B2 Or -SO 2 -R C2 It is. )
  5. The radiation sensitive resin composition according to claim 4, wherein the compound [C] is represented by the following formula (2).
    (In formula (2), Q + Is a monovalent onium cation. Y Is a monovalent carboxylate anion, sulfonate anion or sulfonamide anion. )
  6. Y in the above formula (2) Is a monovalent carboxylate anion. The radiation-sensitive resin composition according to claim 5.
  7. Q in the above formula (2) + The radiation sensitive resin composition of Claim 5 or Claim 6 represented by a following formula (S1).
    (In the formula (S1), R a1 , R b1 And R c1 Each independently represents a hydroxyl group, a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, -SR A1 , -OSO 2 -R B1 Or -SO 2 -R C1 It is. R A1 Is an alkyl group or an aryl group. R B1 And R C1 Are each independently an alkyl group, a cycloalkyl group, an alkoxy group or an aryl group. R a1 , R b1 And R c1 And R A1 , R B1 And R C1 Some or all of the hydrogen atoms of the alkyl group, cycloalkyl group, alkoxy group, and aryl group of may be substituted. m1, n1 and p1 are each independently an integer of 0 to 5. However, m1 + n1 + p1 ≧ 1. R a1 , R b1 And R c1 When there are a plurality of each, a plurality of R a1 , R b1 And R c1 May be the same or different. However, R a1 , R b1 And R c1 At least one of -OSO 2 -R B1 Or -SO 2 -R C1 It is. )
  8. (1) forming a coating film of claims 1 on a substrate using the radiation-sensitive resin composition according to any one of claims 7,
    (2) A step of irradiating at least a part of the coating film with radiation,
    (3) A pattern forming method including a step of heating the coating film irradiated with the radiation, and (4) a step of developing the heated coating film.
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