JP5515471B2 - Radiation sensitive resin composition - Google Patents

Description

The present invention relates to a radiation-sensitive resin composition used in semiconductor manufacturing processes such as ICs, circuit boards such as liquid crystals and thermal heads, and other photolithography processes.
Specifically, the present invention provides a radiation-sensitive resin composition suitable for a photolithography process using an exposure light source such as far ultraviolet light of 220 nm or less, for example, an ArF excimer laser or an electron beam as a light source.

  The chemically amplified radiation-sensitive resin composition generates an acid in an exposed area by irradiation with far ultraviolet light or the like typified by a KrF excimer laser or an ArF excimer laser, and reacts with the acid as a catalyst to react with the exposed area. It is a composition that changes the dissolution rate of the unexposed portion with respect to the developer to form a resist pattern on the substrate.

  The radiation-sensitive acid generator contained in the chemically amplified radiation-sensitive resin composition is required to have excellent transparency to radiation and a high quantum yield upon acid generation. Furthermore, the acid generated by the radiation sensitive acid generator is sufficiently strong, has a sufficiently high boiling point, and has an appropriate diffusion distance in the resist film (hereinafter sometimes referred to as “diffusion length”). Characteristics are required.

  Among the above properties, the structure of the anion moiety is important in an ionic radiation-sensitive acid generator in order to exhibit the acid strength, boiling point and diffusion length. In addition, the structure of the sulfonyl moiety is important in the nonionic radiation-sensitive acid generator having a sulfonyl structure or a sulfonate structure.

  For example, a radiation-sensitive acid generator having a trifluoromethanesulfonyl structure generates a sufficiently strong acid, and the resolution performance as a photoresist is sufficiently high. However, since the boiling point of the acid is low and the acid diffusion length is not appropriate, that is, the acid diffusion length is long, there is a disadvantage that the mask dependency as a photoresist increases. In addition, for example, a radiation-sensitive acid generator having a sulfonyl structure bonded to a large organic group such as a 10-camphorsulfonyl structure has a sufficiently high boiling point of the generated acid, and an appropriate acid diffusion length. Since the acid diffusion length is sufficiently short, the mask dependency is reduced. However, since the acid strength is not sufficient, there is a disadvantage that the resolution performance as a photoresist is not sufficient.

  Here, the radiation sensitive acid generator having a perfluoroalkylsulfonyl structure such as perfluoro-n-octanesulfonic acid (PFOS) is a sufficiently strong acid, has a sufficiently high boiling point of the acid, and a diffusion length. Has been attracting particular attention in recent years.

  However, radiation sensitive acid generators having a perfluoroalkylsulfonyl structure, such as PFOS, are generally suspected of environmental problems due to their low flammability, and human accumulation is suspected. The report by the Environmental Protection Agency (ENVIRONMENTAL PROTECTION AGENCY) (see Non-Patent Document 1) has a drawback in that a proposal for restricting use has been made.

  On the other hand, when more precise line width control is performed, for example, when the device design dimension is sub-half micron or less, the chemically amplified resist has not only excellent resolution performance but also a resist pattern. It is also important that the smoothness of the film surface after formation is excellent. For chemically amplified resists with poor film surface smoothness, when the resist pattern is transferred to the substrate by etching or other treatment, the uneven surface shape of the film surface (hereinafter sometimes referred to as “nano edge roughness”) is transferred to the substrate. As a result, the dimensional accuracy of the pattern decreases. Therefore, it has been reported that there is a possibility that the electrical characteristics of the device may be ultimately lost (for example, see Non-Patent Documents 2 to 5).

JP-B-2-27660

Perfluorinated Sulfonates; Proposed Significant New Use Rule J. et al. Photopolym. Sci. Tech. , P. 571 (1998) Proc. SPIE, Vol. 3333, p. 313 Proc. SPIE, Vol. 3333, p. 634 J. et al. Vac. Sci. Technol. B16 (1), p. 69 (1998)

  From the above, it is possible to form a chemically amplified resist having no defects like the above-mentioned radiation sensitive acid generator having a perfluoroalkylsulfonyl structure such as PFOS, excellent resolution performance and small nano edge roughness. There is an urgent need to develop a radiation-sensitive resin composition.

  The present invention also provides a resist in which the acid generated by exposure is not vaporized, the diffusion length is moderately short, the MEEF (Mask Error Enhancement Factor) is small, and the surface and sidewall smoothness is excellent. The object is to provide a radiation-sensitive resin composition capable of forming a resist film capable of obtaining a pattern.

As a result of intensive studies to achieve the above-mentioned problems, the present inventors have solved the above-mentioned problems with a radiation-sensitive resin composition containing a sulfonic acid onium salt having a specific structure or a sulfonyloxy group-containing radiation-sensitive acid generator. The inventors have found that it is possible to achieve this, and have completed the present invention. That is, according to this invention, the radiation sensitive resin composition shown below is provided.

[1] (A) and a sulfonic acid salt or sulfo Niruokishi group-containing radiation-sensitive acid generator having a partial structure represented by the following general formula (1), (B) a radiation-sensitive resin composition containing a resin, a .

[In General Formula (1), R ¹ represents a substituted or unsubstituted linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms, a substituted or unsubstituted cyclic or cyclic group having 3 to 30 carbon atoms. A monovalent hydrocarbon group having a partial structure of: a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent hetero atom having 4 to 30 carbon atoms; Indicates a group. ]

[2] The radiation sensitive resin composition according to [1], wherein the (A) radiation sensitive acid generator is a compound represented by the following general formula (2).

[In the general formula (2), R ¹ represents a substituted or unsubstituted linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms, a substituted or unsubstituted cyclic group having 3 to 30 carbon atoms, or A monovalent hydrocarbon group having a cyclic partial structure, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a cyclic group optionally having a substituted or unsubstituted monovalent heteroatom having 4 to 30 carbon atoms An organic group is shown. M ⁺ represents a monovalent onium cation. ]

[3] The radiation sensitive resin composition according to the above [2], wherein M ⁺ is a sulfonium cation or an iodonium cation represented by the following general formula (3) or (4).

[In General Formula (3), R ² , R ³ , and R ⁴ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted carbon. The aryl group of formula 6-18 is shown, or any two or more of R ² , R ³ and R ⁴ are bonded to each other to form a ring together with the sulfur atom in the formula. ]

[In the general formula (4), R ⁵ and R ⁶ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted carbon group having 6 to 18 carbon atoms. Or R ⁵ and R ⁶ are bonded to each other to form a ring together with the iodine atom in the formula. ]

[4] The radiation-sensitive resin composition according to [1], wherein the (A) radiation-sensitive acid generator is a compound represented by the following general formula (5).

[In the general formula (5), R ¹ represents a substituted or unsubstituted linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms, a substituted or unsubstituted cyclic group having 3 to 30 carbon atoms, or A monovalent hydrocarbon group having a cyclic partial structure, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a cyclic group optionally having a substituted or unsubstituted monovalent heteroatom having 4 to 30 carbon atoms An organic group is shown. R ⁷ and R ⁸ each independently represent a hydrogen atom or a substituted or unsubstituted monovalent organic group, or R ⁷ and R ⁸ form a ring together with the carbon atoms to which R ⁷ and R ⁸ are bonded to each other; Y represents a single bond, a double bond or a divalent organic group. ]

[5] The radiation sensitive resin composition according to the above [1], wherein the resin (B) contains a repeating unit represented by the following general formula (6).

(In the general formula (6), each R ⁹ independently represents hydrogen, a methyl group or a trifluoromethyl group, R ′ represents a linear alkyl group or branched alkyl group having 1 to 4 carbon atoms, Independently represents a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or two R's are bonded to each other to bond A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms is formed together with the carbon atom.)

  The radiation-sensitive resin composition of the present invention does not vaporize an acid generated by exposure, obtains a resist pattern having a moderately short diffusion length, a small MEEF, and excellent surface and sidewall smoothness and roughness. It is possible to form a resist film that can be formed.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

Sulfonate or sulfo Niruokishi group-containing radiation-sensitive acid generator:
One embodiment of the radiation-sensitive resin composition of the present invention have a sulfonate or sulfo Niruokishi group-containing radiation-sensitive acid generator, having a partial structure represented by the following general formula (1). Such a radiation-sensitive resin composition contains a resin that has an excellent function as a radiation-sensitive acid generator, has a low adverse effect on the environment and the human body, and can obtain a good resist pattern. There is an advantage that a resist film can be formed.

[In General Formula (1), R ¹ represents a substituted or unsubstituted linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms, a substituted or unsubstituted cyclic or cyclic group having 3 to 30 carbon atoms. A monovalent hydrocarbon group having a partial structure of: a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent hetero atom having 4 to 30 carbon atoms; Indicates a group. ]

More specifically, for R ¹ , examples of the unsubstituted linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms include a methyl group, an ethyl group, an n-propyl group, i-propyl group, n-butyl group, t-butyl group, n-pentyl group, i-pentyl group, n-hexyl group, i-hexyl group, n-heptyl group, n-octyl group, i-octyl group, Mention may be made of n-nonyl, n-decyl, 2-ethylhexyl and n-dodecyl.

  Examples of the substituent of the hydrocarbon group include halogen such as fluorine, chlorine, bromine and iodine, hydroxyl group, thiol group, aryl group, alkenyl group and halogen atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus Mention may be made of organic groups containing heteroatoms such as atoms and silicon atoms. Furthermore, a keto group in which two hydrogen atoms on the same carbon of the hydrocarbon group are substituted with one oxygen atom can be exemplified. Any number of these substituents may be present as long as structurally possible. Examples of the linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms substituted with the substituent include a benzyl group, a methoxymethyl group, a methylthiomethyl group, an ethoxymethyl group, a phenoxymethyl group, Methoxycarbonylmethyl group, ethoxycarbonylmethyl group, acetylmethyl group, fluoromethyl group, trifluoromethyl group, 2,2,2-trifluoroethyl group, chloromethyl group, trichloromethyl group, 2-fluoropropyl group, trifluoro Acetylmethyl group, trichloroacetylmethyl group, pentafluorobenzoylmethyl group, aminomethyl group, cyclohexylaminomethyl group, diphenylphosphinomethyl group, trimethylsilylmethyl group, 2-phenylethyl group, 3-phenylpropyl group, 2-aminoethyl Group, hydroxymethyl , Mention may be made of hydroxyethyl groups and hydroxycarbonyl methyl group.

  Examples of the monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 30 carbon atoms include, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a bornyl group, a norbornyl group, an adamantyl group, a pinanyl group, Mention may be made of a tuyoyl group, a carbyl group, a camphanyl group, a cyclopropylmethyl group, a cyclobutylmethyl group, a cyclopentylmethyl group, a cyclohexylmethyl group, a bornylmethyl group, a norbornylmethyl group and an adamantylmethyl group.

  Examples of the substituent of the hydrocarbon group include halogen such as fluorine, chlorine, bromine and iodine, hydroxyl group, thiol group, aryl group, alkenyl group and halogen atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus Mention may be made of organic groups containing heteroatoms such as atoms and silicon atoms. Furthermore, a keto group in which two hydrogen atoms on the same carbon of the hydrocarbon group are substituted with one oxygen atom can be exemplified. Any number of these substituents may be present as long as structurally possible.

  Examples of the monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 30 carbon atoms substituted with the substituent include a 4-fluorocyclohexyl group, a 4-hydroxycyclohexyl group, a 4-methoxycyclohexyl group, Examples include 4-methoxycarbonylcyclohexyl group, 3-hydroxy-1-adamantyl group, 3-methoxycarbonyl-1-adamantyl group, 3-hydroxycarbonyl-1-adamantyl group and 3-hydroxymethyl-1-adamantanemethyl group. it can.

  Examples of the aryl group having 6 to 30 carbon atoms include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, and a 1-phenanthryl group. Examples of the substituent of the aryl group include halogens such as fluorine, chlorine, bromine and iodine, hydroxyl groups, thiol groups, alkyl groups, and halogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms and silicon atoms. The organic group containing the hetero atom of these can be mentioned. Examples of the substituted aryl group having 6 to 30 carbon atoms include o-hydroxyphenyl group, m-hydroxyphenyl group, p-hydroxyphenyl group, 3,5-bis (hydroxy) phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, p-methoxyphenyl group, mesityl group, o-cumenyl group, 2,3-xylyl group, o-fluorophenyl group, m-fluorophenyl group, p-fluorophenyl group, o -Trifluoromethylphenyl group, m-trifluoromethylphenyl group, p-trifluoromethylphenyl group, 3,5-bis (trifluoromethyl) phenyl group, p-bromophenyl group, p-chlorophenyl group and p-iodo Mention may be made of phenyl groups.

  Examples of the cyclic organic group which may have a monovalent heteroatom having 4 to 30 carbon atoms include furyl group, thienyl group, pyranyl group, pyrrolyl group, thiantenyl group, pyrazolyl group, isothiazolyl group, isoxazolyl group, pyrazinyl Groups, pyrimidinyl groups, pyridazinyl groups and monocyclic or polycyclic lactones. Among these, monocyclic or polycyclic lactones include γ-butyrolactone, γ-valerolactone, angelica lactone, γ-hexalactone, γ-heptalactone, γ-octalactone, γ-nonalactone, and 3-methyl-4. -Octanolide (whiskey lactone), γ-decalactone, γ-undecalactone, γ-dodecalactone, γ-jasmolactone (7-decenolactone), δ-hexalactone, 4,6,6 (4,4,6) -Trimethyltetrahydropyran-2-one, δ-octalactone, δ-nonalactone, δ-decalactone, δ-2-decenolactone, δ-undecalactone, δ-dodecalactone, δ-tridecalactone, δ-tetradecalactone , Lactoscatone, ε-decalactone, ε-dodecalactone, cyclohexyllactone, jas Nrakuton include cis-jasmone those lactones and methyl γ- decalactone or below.

(The dotted line indicates the coupling position.)
Examples of the substituent of the cyclic organic group which may have a hetero atom include, for example, halogen such as fluorine, chlorine, bromine and iodine, hydroxyl group, thiol group, aryl group, alkenyl group, halogen atom, oxygen Mention may be made of organic groups containing heteroatoms such as atoms, nitrogen atoms, sulfur atoms, phosphorus atoms and silicon atoms. Furthermore, the keto group by which two hydrogen atoms on the same carbon of the cyclic organic group which may have the said hetero atom were substituted by one oxygen atom can be illustrated. Any number of these substituents may be present as long as structurally possible.

  Examples of the cyclic organic group which may have a substituted monovalent heteroatom having 4 to 30 carbon atoms include a 2-bromofuryl group and a 3-methoxythienyl group.

  Therefore, the structure represented by the general formula (1) can be illustrated more specifically as follows.

  Moreover, as a preferable sulfonate having the partial structure represented by the general formula (1), for example, a sulfonate represented by the following general formula (2) can be given.

In [the formula (2), ^{R 1} has the same meaning as ^{R 1} in the general formula (1). M ⁺ represents a monovalent onium cation. ]

  Examples of the monovalent onium cation include onium cations of O, S, Se, N, P, As, Sb, Cl, Br, and I. Of these onium cations, S and I onium cations are preferred.

In the general formula (2), examples of the M ⁺ monovalent onium cation include those represented by the following general formula (3) or general formula (4).

[In General Formula (3), R ² , R ³ , and R ⁴ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted carbon. The aryl group of formula 6-18 is shown, or any two or more of R ² , R ³ and R ⁴ are bonded to each other to form a ring together with the sulfur atom in the formula. ]

[In the general formula (4), R ⁵ and R ⁶ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted carbon group having 6 to 18 carbon atoms. Or R ⁵ and R ⁶ are bonded to each other to form a ring together with the iodine atom in the formula. ]

  The following general formulas (3-1) and (3-2) are preferable as the onium cation of the formula (3), and the following general formula (4-1) is preferable as the onium cation of the formula (4).

[In General Formula (3-1), a plurality of R ^a , R ^b and R ^c may be the same or different from each other, and R ^a , R ^b and R ^c are each a hydrogen atom, substituted or unsubstituted. A linear or branched alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or two or more of R ^a , R ^b and R ^c are bonded to each other To form a ring. q1, q2, and q3 each independently represents an integer of 0 to 5. In the general formula (3-2), a plurality of R ^d and R ^e may be the same or different from each other, and R ^d is a hydrogen atom, a substituted or unsubstituted C 1-8 linear or branched alkyl group or a substituted or unsubstituted aryl group having 6 to 8 carbon atoms or two or more R ^d, are combined to form a ring to each other. R ^e represents a hydrogen atom, a substituted or unsubstituted linear or branched alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 7 carbon atoms, or two or more R ^e is bonded to each other to form a ring. q4 represents an integer of 0 to 7, q5 represents an integer of 0 to 6, and q6 represents an integer of 0 to 3. ]

[In the general formula (4-1), a plurality of R ^f and R ^g may be the same or different from each other, and R ^f and R ^g are each a hydrogen atom, a substituted or unsubstituted carbon atom having 1 to 12 carbon atoms. It represents a linear or branched alkyl group or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or two or more R ^f and R ^g are bonded to each other to form a ring. q7 and q8 each independently represents an integer of 0 to 5. ]

  Preferred examples of the sulfonium cation of general formula (3-1) and general formula (3-2) include the following formulas (i-1) to (i-64), and preferred general formula (4-1) Examples of the iodonium cation of) include the following formulas (ii-1) to (ii-39).

  Among these preferable monovalent onium cations, for example, the formula (i-1), the formula (i-2), the formula (i-6), the formula (i-8), the formula (i-13), the formula (I-19), formula (i-25), formula (i-27), formula (i-29), formula (i-33), formula (i-51) or formula (i-54) A sulfonium cation; iodonium cation represented by formula (ii-1) or (ii-11) is more preferred.

The monovalent onium cation represented by M ⁺ in the general formula (1) is described in, for example, Advances in Polymer Science, Vol. 62, p. It can be produced according to the general method described in 1-48 (1984).

Preferred examples sulfo Niruokishi group-containing compound having a partial structure represented by the general formula (1), for example, represented by N- sulfonyloxyimide compound of the following general formula (5) (hereinafter, "N- sulfonyloxy Imide compound (5) ”).

[In the general formula (5), R ¹ represents a substituted or unsubstituted linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms, a substituted or unsubstituted cyclic group having 3 to 30 carbon atoms, or A monovalent hydrocarbon group having a cyclic partial structure, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a cyclic group optionally having a substituted or unsubstituted monovalent heteroatom having 4 to 30 carbon atoms An organic group is shown. R ⁷ and R ⁸ each independently represent a hydrogen atom or a substituted or unsubstituted monovalent organic group, or R ⁷ and R ⁸ form a ring together with the carbon atoms to which R ⁷ and R ⁸ are bonded to each other; Represents a single bond, a double bond or a divalent organic group. ]

Specific examples of R ¹ include those described above.

In the general formula (5), examples of the preferable imide group bonded to the sulfonyloxy group (SO ₂ —O—) in each formula include groups of the following formulas (iii-1) to (iii-9). Can do.

  Of these imide groups, for example, a group represented by the formula (iii-1), formula (iii-4), formula (iii-8), or formula (iii-9) is preferable.

  The radiation-sensitive acid generator contained in the radiation-sensitive resin composition of the present embodiment generates an acid by dissociating the monovalent onium cation upon exposure or heating. Specifically, the sulfonic acid represented by the following general formula (1a) is generated.

(In the general formula (1a), R ¹ represents a substituted or unsubstituted linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms, a substituted or unsubstituted cyclic group having 3 to 30 carbon atoms, or A monovalent hydrocarbon group having a cyclic partial structure, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a cyclic group optionally having a substituted or unsubstituted monovalent heteroatom having 4 to 30 carbon atoms Indicates an organic group.)

Specific examples of R ¹ include those described above.

  The radiation-sensitive acid generator contained in the radiation-sensitive resin composition of the present embodiment has a fluorine-containing electron withdrawing group that is strong at the α-position of the sulfonyl group in the structure, and thus is generated upon exposure. The acidity of the sulfonic acid represented by the general formula (1a) is high. Further, the radiation-sensitive acid generator contained in the radiation-sensitive resin composition of the present embodiment functions as a radiation-sensitive acid generator, has a high boiling point, and hardly volatilizes during the photolithography process. The acid diffusion length in the resist film is short, that is, the acid diffusion length is moderate. Furthermore, since the fluorine atom content in the sulfonic acid represented by the general formula (1a) is smaller than that of the higher perfluoroalkanesulfonic acid, in addition to showing good combustibility, human body accumulation is low. There is an advantage.

Radiation sensitive resin composition:
<Radiation sensitive acid generator (A)>
An acid generator having a partial structure of the general formula (1) is blended in the radiation sensitive resin composition of the present invention. In the radiation-sensitive resin composition of the present invention, the radiation-sensitive acid generator can be used alone or in admixture of two or more.

  In the radiation-sensitive resin composition of the present invention, the amount of the radiation-sensitive acid generator having the structure of the general formula (1) is the amount of the radiation-sensitive acid generator or the following other acid generators used in some cases. Although it varies depending on the type, it is usually 0.1 to 25 with respect to 100 parts by mass of an acid-dissociable group-containing resin or an alkali-soluble resin (hereinafter sometimes referred to as “resin having a repeating unit” or “resin”). Preferably it is 0.1-20 mass parts, More preferably, it is 0.1-15 mass parts, Most preferably, it is 0.2-15 mass parts. In this case, if the amount of the radiation-sensitive acid generator used is less than 0.1 parts by mass, the desired effect of the present invention may not be sufficiently expressed. In addition, the pattern shape, heat resistance and the like may be reduced.

  In the radiation sensitive resin composition of the present invention, one or more radiation sensitive acid generators (hereinafter referred to as “other acid generators”) other than the radiation sensitive acid generator of the general formula (1) are used in combination. can do. Other acid generators will be described later in <Other Radiation Sensitive Acid Generator>.

Acid-dissociable group-containing resin or alkali-soluble resin:
<Resin (B)>
As said acid dissociable group containing resin or alkali-soluble resin, as a repeating unit containing an acid dissociable group, the repeating unit (henceforth "repeating unit (6)") represented by following General formula (6) is shown. It is preferable to contain.

(In the general formula (6), each R ⁹ independently represents hydrogen, a methyl group or a trifluoromethyl group, R ′ represents a linear alkyl group or branched alkyl group having 1 to 4 carbon atoms, Independently represents a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or two R's are bonded to each other to bond A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms is formed together with the carbon atom.)

  Examples of the linear or branched alkyl group having 1 to 4 carbon atoms represented by R ′ and R in the general formula (6) include a methyl group, an ethyl group, a propyl group, an isopropyl group, an isobutyl group, and t- A butyl group can be mentioned. Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R include cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane and cyclodecane; dicyclopentane, Examples include a group obtained by removing one hydrogen atom from a bridged alicyclic skeleton such as dicyclopentene, tricyclodecane, tetracyclododecane, adamantane, etc., and two Rs are formed together with a carbon atom to which both are bonded. Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include groups in which two hydrogen atoms have been removed from the bridged alicyclic skeleton.

  Examples of the repeating unit (6) include a repeating unit represented by the following general formula (6-1), a repeating unit represented by the following general formula (6-2), and the following general formula (6-3). At least one of the repeating units is preferred.

[In the general formulas (6-1) to (6-3), each R ⁹ independently represents hydrogen, a methyl group or a trifluoromethyl group, and R ¹⁰ represents a linear alkyl group having 1 to 4 carbon atoms or a branched group. An alkyl group, R ¹¹ independently represents a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group, and k is an integer of 0 to 4; ]

  Preferred examples of the monomer that gives the repeating unit (6-1) include (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid 2-ethyladamantyl-2-yl ester, (Meth) acrylic acid 2-n-propyladamantyl-2-yl ester, (meth) acrylic acid 2-isopropyladamantyl-2-yl ester, and the like.

  Preferable monomers that give the repeating unit (6-2) include, for example, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1- (adamantane) -1-yl) -1-ethylethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylpropyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1- Examples thereof include ethyl propyl ester.

  Preferred examples of the monomer that gives the repeating unit (6-3) include 1-methylcyclopentyl (meth) acrylate, 1-ethylcyclopentyl (meth) acrylate, 1-isopropylcyclopentyl (meth) acrylate, 1-methylcyclohexyl (meth) acrylate, 1-ethylcyclohexyl (meth) acrylate, 1-isopropylcyclohexyl (meth) acrylate, 1-isopropylcycloheptyl (meth) acrylate, 1-ethylcyclo (meth) acrylate Examples include octyl.

  The resin (B) may contain one or more repeating units (6) obtained from these exemplified monomers.

  The resin (B) can contain one or more repeating units other than the repeating unit (6) (hereinafter sometimes referred to as “other repeating units”).

  As other repeating units, repeating units represented by the following general formulas (7-1) to (7-6) (hereinafter sometimes referred to as “other repeating units (7)”), general formula (8) ) (Hereinafter also referred to as “other repeating unit (8)”), a repeating unit represented by the general formula (9) (hereinafter referred to as “other repeating unit (9)”). And at least one repeating unit selected from the group consisting of repeating units represented by the general formula (10) (hereinafter sometimes referred to as “other repeating units (10)”). It is preferable.

In the formulas (7-1) to (7-6), R ⁹ independently represents hydrogen, a methyl group or a trifluoromethyl group, and R ¹² may have a hydrogen atom or a substituent. an alkyl group having 1 to 4 carbon atoms, R ¹³ represents a hydrogen atom or a methoxy group. A represents a single bond or a methylene group, and B represents an oxygen atom or a methylene group. l represents an integer of 1 to 3, and m is 0 or 1.

In the general formula (8), R ⁹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and X is a polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms. The polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms is at least selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a cyano group, and a hydroxyalkyl group having 1 to 10 carbon atoms. Even if it is substituted by 1 type, it does not need to be substituted.

In the general formula (9), R ¹⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, or a hydroxymethyl group, and R ¹⁵ represents a divalent chain or cyclic hydrocarbon group. Show.

In General Formula (10), R ¹⁶ represents hydrogen or a methyl group, R ¹⁷ represents a single bond or a divalent organic group having 1 to 3 carbon atoms, and Z represents a single bond or 1 to 1 carbon atoms independently of each other. 3 represents a divalent organic group, and R ¹⁸ independently represents a hydrogen atom, a hydroxyl group, a cyano group, or a COOR ¹⁹ group (provided that R ¹⁹ represents a hydrogen atom, a straight chain having 1 to 4 carbon atoms or A branched alkyl group or an alicyclic alkyl group having 3 to 20 carbon atoms is shown.). When at least one of the three R ¹⁸ is not a hydrogen atom, and R ¹⁷ is a single bond, at least one of the three Z is preferably a divalent organic group having 1 to 3 carbon atoms. .

Among the monomers giving another repeating unit (7), (meth) acrylic acid-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nona-2 is preferable. -Yl ester, (meth) acrylic acid-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (meth) acrylic acid-5 -Oxo-4-oxa-tricyclo [5.2.1.0 ^3,8 ] dec-2-yl ester, (meth) acrylic acid-10-methoxycarbonyl-5-oxo-4-oxa-tricyclo [5. 2.1.0 ^3,8 ] non-2-yl ester, (meth) acrylic acid-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid -4-methoxycarbonyl-6 Oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (Meth) acrylic acid-4-methoxycarbonyl-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (meth) acrylic acid-2-oxotetrahydropyran-4-yl ester , (Meth) acrylic acid-4-methyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-ethyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4 -Propyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-2-oxotetrahydrofuran-4-yl ester, (meth) acrylic acid Rylic acid-5,5-dimethyl-2-oxotetrahydrofuran-4-yl ester, (meth) acrylic acid-3,3-dimethyl-2-oxotetrahydrofuran-4-yl ester, (meth) acrylic acid-2-oxo Tetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5,5-dimethyl-2-oxotetrahydrofuran-3-yl ester , (Meth) acrylic acid-5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid-3,3-dimethyl-5-oxotetrahydrofuran-2-ylmethyl ester and (meth) acrylic acid-4,4 -Dimethyl-5-oxotetrahydrofuran-2-ylmethyl ester It is.

X in the other repeating unit (8) represented by the general formula (8) is preferably a polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms. Examples of such polycyclic alicyclic hydrocarbon groups include bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, and tricyclo [5.2.1.0 ^2,6 ]. Decane, tetracyclo [6.2.1.1 ^3,6 . And hydrocarbon groups composed of alicyclic rings derived from cycloalkanes such as 0 ^2,7 ] dodecane and tricyclo [3.3.1.1 ^3,7 ] decane.

  These cycloalkane-derived alicyclic rings may have a substituent, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group. , One or more of linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as 1-methylpropyl group and t-butyl group may be substituted. These are represented by the following specific examples, but are not limited to those substituted by these alkyl groups, but are hydroxyl groups, cyano groups, C1-C10 hydroxyalkyl groups, carboxyls. It may be substituted with a group or oxygen. Moreover, these other repeating units (8) can contain 1 type (s) or 2 or more types.

Among the monomers that give other repeating units (8), (meth) acrylic acid-bicyclo [2.2.1] heptyl ester, (meth) acrylic acid-cyclohexyl ester, (meth) are preferable. Acrylic acid-bicyclo [4.4.0] decanyl ester, (meth) acrylic acid-bicyclo [2.2.2] octyl ester, (meth) acrylic acid-tricyclo [5.2.1.0 ^2,6 ] Decanyl ester, (meth) acrylic acid-tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecanyl ester and (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 ] decanyl ester.

R ¹⁵ of the other repeating unit (9) represented by the general formula (9) is preferably a divalent chain or cyclic hydrocarbon group, and may be an alkylene glycol group or an alkylene ester group. Preferred R ¹⁵ includes a methylene group, an ethylene group, a propylene group such as a 1,3-propylene group or a 1,2-propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, Nonamethylene group, Decamemethylene group, Undecamethylene group, Dodecamethylene group, Tridecamethylene group, Tetradecamethylene group, Pentadecamethylene group, Hexadecamethylene group, Heptadecamethylene group, Octadecamethylene group, Nonadecamethylene group, Icosalen group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl- 1,4-butylene group, methylidene group, ethylidene group, propylidene group or 2-propylidene group Saturated chain hydrocarbon groups such as ethylene groups, cyclobutylene groups such as 1,3-cyclobutylene groups, cyclopentylene groups such as 1,3-cyclopentylene groups, and cyclohexylenes such as 1,4-cyclohexylene groups A monocyclic hydrocarbon ring group such as a cycloalkylene group having 3 to 10 carbon atoms such as a cyclooctylene group such as a 1,5-cyclooctylene group, a 1,4-norbornylene group or a 2,5-norbornylene group Such as norbornylene group, 1,5-adamantylene group, adamantylene group such as 2,6-adamantylene group, etc., bridged cyclic hydrocarbon ring such as 2-4 cyclic hydrocarbon ring group having 4-30 carbon atoms Groups.

Among the monomers that give other repeating units (9), (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-3-propyl) ester is preferable. , (Meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-tri Fluoromethyl-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 (meta Acrylic acid 4 - {[9- (1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl] tetracyclo [6.2.1.1 ^{3, 6.} 0 ^2,7 ] dodecyl} ester.

In another repeating unit (10) represented by the general formula (10), R ¹⁷ represents a single bond or a divalent organic group having 1 to 3 carbon atoms, and Z represents a single bond or 1 carbon atom independently of each other. The divalent organic group having 3 to 3 and the divalent organic group having 1 to 3 carbon atoms represented by R ¹⁷ and Z includes a methylene group, an ethylene group, and a propylene group. R ^{19 of the} —COOR ¹⁹ group represented by R ¹⁸ in the other repeating unit (10) represented by the general formula (10) is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or An alicyclic alkyl group having 3 to 20 carbon atoms is shown. Examples of the linear or branched alkyl group having 1 to 4 carbon atoms in R ¹⁹ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, Examples thereof include a 1-methylpropyl group and a t-butyl group. Examples of the alicyclic alkyl groups of said 3 to 20 carbon _atoms, -C _{n H 2n-1} cycloalkyl group (n is an integer of 3 to 20) represented by, for example, cyclopropyl group, cyclobutyl group, Cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, polycyclic alicyclic alkyl group such as bicyclo [2.2.1] heptyl group, tricyclo [5.2.1.0 ^2,6 ] decyl group , Tetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecanyl group, adamantyl group, etc., or one or more of linear, branched or cyclic alkyl groups and a part of cycloalkyl group or polycyclic alicyclic alkyl group Examples include substituted groups.

  Among the monomers giving other repeating units (10), preferred monomers are (meth) acrylic acid 3-hydroxyadamantan-1-yl ester, (meth) acrylic acid 3,5-dihydroxyadamantane-1 -Yl ester, (meth) acrylic acid 3-hydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-methyl Adamantane-1-yl ester, (meth) acrylic acid 3,5-dihydroxy-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-yl ester and ( (Meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-ylme Glycol ester and the like.

  Examples of repeating units other than the repeating units represented by the above repeating units (6) to (10) (hereinafter sometimes referred to as “further repeating units”) include, for example, dicyclopentenyl (meth) acrylate and (meta ) (Meth) acrylic acid esters having a bridged hydrocarbon skeleton such as adamantylmethyl acrylate; carboxynorbornyl (meth) acrylate, carboxytricyclodecanyl (meth) acrylate and carboxy (meth) acrylate Carboxyl group-containing esters having a bridged hydrocarbon skeleton of an unsaturated carboxylic acid such as tetracycloundecanyl;

Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-methylpropyl (meth) acrylate, 1-methyl (meth) acrylate Propyl, t-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, cyclopropyl (meth) acrylate, ( (Meth) acrylic acid cyclopentyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid 4-methoxycyclohexyl, (meth) acrylic acid 2-cyclopentyloxycarbonylethyl, (meth) acrylic acid 2-cyclohexyloxycarbonylethyl and (meth) Acrylic acid 2- (4-methoxycyclohexyl) No bridged hydrocarbon skeleton such as oxycarbonyl ethyl (meth) acrylate;

α-hydroxymethyl acrylate esters such as methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, n-propyl α-hydroxymethyl acrylate and n-butyl α-hydroxymethyl acrylate; (meth) acrylonitrile , Α-chloroacrylonitrile, crotonnitrile, maleinonitrile, fumaronitrile, mesacononitrile, citraconitrile, itaconnitrile and other unsaturated nitrile compounds; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, crotonamide, maleinamide , Fumaramide, mesaconamide, citraconic amide and itaconic amide compounds; N- (meth) acryloylmorpholine, N-vinyl-ε-caprolactam, N-vinylpyrrole Other nitrogen-containing vinyl compounds such as ethylene, vinylpyridine and vinylimidazole; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride and mesacone Unsaturated carboxylic acids (anhydrides) such as acids; 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4- (meth) acrylic acid 4- Carboxyl group-containing esters having no bridged hydrocarbon skeleton of unsaturated carboxylic acid such as carboxybutyl and 4-carboxycyclohexyl (meth) acrylate;

1,2-adamantanediol di (meth) acrylate, 1,3-adamantanediol di (meth) acrylate, 1,4-adamantanediol di (meth) acrylate, tricyclodecanyl dimethylol di (meth) acrylate, etc. A polyfunctional monomer having a bridged hydrocarbon skeleton;

Methylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2,5-dimethyl-2,5-hexanediol di ( (Meth) acrylate, 1,8-octanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,4-bis (2-hydroxypropyl) benzenedi (meth) acrylate and 1,3-bis List units in which a polymerizable unsaturated bond of a polyfunctional monomer such as a polyfunctional monomer having no bridged hydrocarbon skeleton such as (2-hydroxypropyl) benzenedi (meth) acrylate is cleaved Can do.

  In the resin (B), the content of the repeating unit (6) is preferably 10 to 80 mol%, more preferably 15 to 75 mol%, based on all the repeating units of the resin. It is especially preferable that it is 20-70 mol%. When the content ratio of the repeating unit (6) is less than 10 mol%, the solubility of the resist film formed by the radiation-sensitive resin composition of the present embodiment in the alkaline developer is lowered, and thus development defects occur. Or the resolution may be reduced. On the other hand, if it exceeds 80 mol%, the resolution may be lowered.

  The resin (B) can be synthesized according to a conventional method such as radical polymerization. For example, a reaction solution containing each monomer and a radical initiator is dropped into a reaction solution containing a reaction solvent or monomer. Polymerization reaction, or a reaction solution containing each monomer and a reaction solution containing a radical initiator are dropped separately into a reaction solution containing a reaction solvent or monomer, respectively, to cause a polymerization reaction. In addition, a method in which a reaction solution containing each monomer separately and a reaction solution containing a radical initiator are separately dropped into a reaction solution containing a reaction solvent or a monomer to cause a polymerization reaction. Is preferred.

  The reaction temperature in each of the above reactions can be appropriately set depending on the initiator species, but is generally 30 ° C to 180 ° C. Preferably it is 40 to 160 degreeC, More preferably, it is 50 to 140 degreeC. The time required for dropping can be variously set depending on the reaction temperature, the type of initiator, and the monomer to be reacted, but is 30 minutes to 8 hours. Preferably it is 45 minutes-6 hours, More preferably, it is 1 hour-5 hours. Moreover, although the total reaction time including dripping time can be variously set like the above, it is 30 minutes-8 hours. Preferably it is 45 minutes-7 hours, More preferably, it is 1 hour-6 hours. When dropping into a solution containing monomers, the monomer content in the dropped solution is preferably 30 mol% or more, more preferably 50 mol% or more, still more preferably 70 mol based on the total amount of monomers used for polymerization. % Or more.

  Examples of the radical initiator used in the polymerization include 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropylpropionitrile), 2, 2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane- 1-carbonitrile), 2,2′-azobis (2-methyl-N-phenylpropionamidine) dihydrochloride, 2,2′-azobis (2-methyl-N-2-propenylpropionamidine) dihydrochloride, 2, 2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis {2-methyl-N [1,1-bis (hydroxymethyl) 2-hydroxyethyl] propionamide}, dimethyl-2,2′-azobis (2-methylpropionate), 4,4′-azobis (4-cyanovaleric acid) and 2,2′-azobis (2- (hydroxymethyl) propionitrile) and the like can be mentioned. These initiators can be used alone or in admixture of two or more.

  The solvent used for the polymerization can be used unless it dissolves the monomers used and inhibits the polymerization (inhibition of polymerization (eg, nitrobenzenes, chain transfer, eg, mercapto compound)). Examples include alcohols, ethers, ketones, amides, esters and lactones, and nitriles and mixtures thereof. Examples of alcohols include methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and 1-methoxy-2-propanol. Examples of ethers include propyl ether, isopropyl ether, butyl methyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane and 1,3-dioxane. Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, and methyl isobutyl ketone. Examples of amides include N, N-dimethylformamide and N, N-dimethylacetamide. Esters and lactones include ethyl acetate, methyl acetate, isobutyl acetate and γ-butyrolactone. Examples of nitriles include acetonitrile, propionitrile, and butyronitrile. These solvents can be used alone or in admixture of two or more.

As described above, after the polymerization reaction, the obtained resin is preferably recovered by a reprecipitation method. That is, after the polymerization is completed, the reaction solution is put into a reprecipitation solvent, and the target resin is recovered as powder.
Examples of the reprecipitation solvent include water, alcohols, ethers, ketones, amides, esters and lactones, and nitriles alone and a mixture thereof. Examples of alcohols include methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, propylene glycol and 1-methoxy-2-propanol. Examples of ethers include propyl ether, isopropyl ether, butyl methyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane and 1,3-dioxane. Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, and methyl isobutyl ketone. Examples of amides include N, N-dimethylformamide and N, N-dimethylacetamide. Esters and lactones include ethyl acetate, methyl acetate, isobutyl acetate and γ-butyrolactone. Examples of nitriles include acetonitrile, propionitrile, and butyronitrile.

  The resin contained in the radiation-sensitive resin composition of the present embodiment preferably has a weight average molecular weight (hereinafter referred to as “Mw”) measured by gel permeation chromatography of 1,000 to 100,000. More preferably, it is 1,500-80,000, and it is especially preferable that it is 2,000-50,000. If the Mw of the resin is less than 1,000, heat resistance when a resist is formed may be reduced. On the other hand, if it exceeds 100,000, the developability when a resist is formed may be lowered. Further, the ratio (Mw / Mn) of Mw and number average molecular weight (hereinafter referred to as “Mn”) of the resin is preferably 1 to 5, and more preferably 1 to 3.

  In addition, the polymerization reaction liquid obtained by the above polymerization is preferably as less as possible for impurities such as halogen and metal, and when there are few impurities, the sensitivity, resolution, process stability, pattern shape, etc. when forming a resist can be further improved. Can do. Examples of the resin purification method include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation. . In this invention, the said resin can be used individually or in mixture of 2 or more types.

<Solvent (D)>:
Examples of the solvent contained in the radiation-sensitive resin composition of the present embodiment include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, and ethylene glycol mono-n-butyl ether. Ethylene glycol monoalkyl ether acetates such as acetate;

Propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether and propylene glycol mono-n-butyl ether; propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol di-n Propylene glycol dialkyl ethers such as propyl ether and propylene glycol di-n-butyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate and propylene glycol mono-n-butyl ether acetate Propile etc. Glycol monoalkyl ether acetates;

Lactic acid esters such as methyl lactate, ethyl lactate, n-propyl lactate and i-propyl lactate; formate esters such as n-amyl formate and i-amyl formate; ethyl acetate, n-propyl acetate, i-acetate Acetates such as propyl, n-butyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, 3-methoxybutyl acetate and 3-methyl-3-methoxybutyl acetate; i-propyl propionate, propionate Propionates such as n-butyl acid, i-butyl propionate and 3-methyl-3-methoxybutyl propionate; ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, 2-hydroxy-3- Methyl methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate , Ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, 3-methyl-3-methoxybutylbutyrate, methyl acetoacetate, ethyl acetoacetate, methyl pyruvate and ethyl pyruvate Other esters; aromatic hydrocarbons such as toluene and xylene;

Ketones such as methyl ethyl ketone, 2-pentanone, 2-hexanone, 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone; N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethyl Examples thereof include amides such as acetamide and N-methylpyrrolidone; lactones such as γ-butyrolacun. These solvents can be used alone or in admixture of two or more.

<Other radiation sensitive acid generator>:
In addition to the acid generator represented by the general formula (1), the radiation-sensitive resin composition of the present embodiment may be referred to as other radiation-sensitive acid generator (hereinafter referred to as “other acid generator”). ) Can be contained. Examples of other acid generators include onium salt compounds and sulfonic acid compounds.

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

  Specifically, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t -Butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, cyclohexyl, 2-oxocyclohexyl, methylsulfonium trifluoromethanesulfonate, dicyclohexyl, 2-oxocyclohexyl Sulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium trifluoromethanes Honeto,

Bis (4-t-butylphenyl) iodonium nonafluorobutanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium perfluorooctanesulfonate, bis (4-t- Butylphenyl) iodonium p-toluenesulfonate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate, 4-trifluoromethylbenzenesulfonate,

Bis (4-t-butylphenyl) iodonium perfluorobenzenesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodoniumbenzenesulfonate, diphenyliodonium10-camphorsulfonate, diphenyliodonium-4-trifluoromethylbenzenesulfonate, diphenyliodonium perfluorobenzenesulfonate ,

Bis (p-fluorophenyl) iodonium trifluoromethanesulfonate, bis (p-fluorophenyl) iodonium nonafluoromethanesulfonate, bis (p-fluorophenyl) iodonium 10-camphorsulfonate, (p-fluorophenyl) (phenyl) iodonium trifluoromethane Sulfonate,

Triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium perfluorooctanesulfonate, triphenylsulfonium-2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate, Triphenylsulfonium-2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium benzenesulfonate, triphenylsulfonium 10-camphorsulfonate, triphenylsulfonium 4-trifluoromethylbenzenesulfonate,

Triphenylsulfonium perfluorobenzenesulfonate, 4-hydroxyphenyl diphenylsulfonium trifluoromethanesulfonate, tris (p-methoxyphenyl) sulfonium nonafluorobutanesulfonate, tris (p-methoxyphenyl) sulfonium trifluoromethanesulfonate, tris (p-methoxyphenyl) ) Sulfonium perfluorooctane sulfonate, tris (p-methoxyphenyl) sulfonium p-toluenesulfonate, tris (p-methoxyphenyl) sulfonium benzene sulfonate, tris (p-methoxyphenyl) sulfonium 10-camphor sulfonate, tris (p-fluorophenyl) ) Sulfonium trifluoromethanesulfonate, tris (p-fluorophenyl) Sulfonium p-toluenesulfonate, (p-fluorophenyl) diphenylsulfonium trifluoromethanesulfonate, 4-butoxy-1-naphthyltetrahydrothiophenium nonafluorobutanesulfonate and 4-butoxy-1-naphthyltetrahydrothiophenium-2-bicyclo [ 2.2.1] Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate.

  Examples of the sulfonic acid compounds include alkyl sulfonic acid esters, alkyl sulfonic acid imides, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and imino sulfonates.

  Specifically, benzoin tosylate, pyrogallol tris (trifluoromethanesulfonate), nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, trifluoromethanesulfonylbicyclo [2.2.1] hept-5-ene- 2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, perfluoro-n-octanesulfonylbicyclo [2.2.1] hept -5-ene-2,3-dicarbodiimide, N-hydroxysuccinimide trifluoromethanesulfonate, N-hydroxysuccinimide nonafluoro-n-butanesulfonate, N-hydroxysuccinimide perfluoro-n-octanesulfonate, 1,8-naphthalenedical Phosphate trifluoromethane sulfonate, can be exemplified 1,8-naphthalenedicarboxylic acid imide nonafluoro -n- butane sulfonate and 1,8-naphthalenedicarboxylic acid imide perfluoro -n- octanesulfonate.

  Among these other acid generators, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, Bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, cyclohexyl, 2-oxocyclohexyl, methylsulfonium trifluoromethanesulfonate, dicyclohexyl 2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium tri Le Oro methanesulfonate,

Trifluoromethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide , Perfluoro-n-octanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, N-hydroxysuccinimide trifluoromethanesulfonate, N-hydroxysuccinimide nonafluoro-n- Butanesulfonate, N-hydroxysuccinimide perfluoro-n-octanesulfonate, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate, triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, Phenylsulfonium-2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate, triphenylsulfonium-2-bicyclo [2.2.1] hept-2-yl-1,1, 2,2-tetrafluoroethanesulfonate, 4-butoxy-1-naphthyltetrahydrothiophenium nonafluorobutanesulfonate and 4-butoxy-1-naphthyltetrahydrothiophenium-2-bicyclo [2.2.1] hepta-2 -Iyl-1,1,2,2-tetrafluoroethanesulfonate is preferred. In addition, the said other acid generator can be used individually or in mixture of 2 or more types.

  When the radiation sensitive resin composition of the present embodiment contains the other acid generator, from the viewpoint of ensuring the sensitivity and developability of the resist film formed by the radiation sensitive resin composition of the present embodiment, It is preferable that the compounding quantity of an acid generator is 0.5-30 mass parts with respect to 100 mass parts of radiation sensitive acid generators which have the partial structure represented by General formula (1), 1-25 More preferably, it is part by mass. There exists a possibility that the resolution of a resist film may fall that the said content is less than 0.5 mass part. On the other hand, if it exceeds 30 parts by mass, the transparency of the radiation is lowered, and it may be difficult to obtain a rectangular resist pattern.

<Other additives>:
The radiation-sensitive resin composition of the present embodiment further includes an acid diffusion controller (C), an alicyclic additive having an acid-dissociable group, a surfactant, a sensitizer, and an alkali-soluble resin as necessary. Various additives such as a low-molecular alkali solubility control agent having an acid-dissociable protecting group, an antihalation agent, a storage stabilizer, and an antifoaming agent can be blended.

  The acid diffusion controller (C) used in the present invention controls the diffusion phenomenon in the resist film of the acid generated from the acid generator by exposure, and suppresses an undesirable chemical reaction in the non-exposed region. By blending such an acid diffusion controller (C), the storage stability of the resulting radiation-sensitive resin composition is improved, the resolution as a resist is further improved, and the heat treatment from exposure to exposure is performed. The change in the line width of the resist pattern due to the fluctuation of the holding time (PED) up to the above can be suppressed, and a composition having excellent process stability is obtained.

  The acid diffusion controller (C) is preferably an acid diffusion controller (a) represented by the following formula (11).

In the general formula (11), R ²⁰ and R ²¹ are each independently a hydrogen atom, a linear, branched or cyclic substituent having 1 to 20 carbon atoms, an aryl group or an aralkyl. R ²⁰ or R ²¹ may be bonded to each other to form a divalent saturated or unsaturated hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof together with the carbon atom to which each group is bonded. . )

  Examples of the acid diffusion controller (a) represented by the formula (11) include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt- Butoxycarbonyldi-n-decylamine, Nt-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N- Methyl-1-adamantylamine, (S)-(−)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonylpyrrolidine, N N′-di-t-butoxycarbonylpiperazine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt -Butoxycarbonyl-4,4'-diaminodiphenylmethane, N, N'-di-t-butoxycarbonylhexamethylenediamine, N, N, N'N'-tetra-t-butoxycarbonylhexamethylenediamine, N, N ' -Di-t-butoxycarbonyl-1,7-diaminoheptane, N, N'-di-t-butoxycarbonyl-1,8-diaminooctane, N, N'-di-t-butoxycarbonyl-1,9- Diaminononane, N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl- , 12-diaminododecane, N, N′-di-t-butoxycarbonyl-4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole and N- Examples include N-t-butoxycarbonyl group-containing amino compounds such as t-butoxycarbonyl-2-phenylbenzimidazole.

  As the acid diffusion control agent (C), a compound that loses acid diffusion controllability by exposure to light (hereinafter also referred to as “acid diffusion control agent (b)”) is preferably used.

  As the acid diffusion controller (b),

X ⁺ Z ^- (12)

(In the general formula (12), X ⁺ is a cation represented by the following general formula (12-1) or (12-2). Z ⁻ is OH ⁻ , R ²² —COO ⁻ , or An anion represented by R ²² —SO ₃ ^— (wherein R ²² is an optionally substituted alkyl group or aryl group))

(In the general formula ^(12-1), R 23 ^{to R 25} are independently of each other hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group or a halogen atom, the general formula (12-2) R ²⁶ and R ²⁷ are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom)

X ⁺ in the general formula (12) is a cation represented by the general formula (12-1) or (12-2) as described above. R ^{23 to} R ²⁵ in the general formula (12-1) are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom. Among these, a hydrogen atom, an alkyl group, An alkoxy group and a halogen atom are preferable. R ²⁶ and R ²⁷ in general formula (12-2) are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom, and among these, a hydrogen atom, an alkyl group, A halogen atom is preferred.

Formula (12) in the ^Z - ^{is, OH -, R 22 -COO -} , ^or, R 22 -SO ₃ ^- is an anion represented by. R ²² is an optionally substituted alkyl group or aryl group, and among these, an aryl group is preferable because of the effect of reducing the solubility of the composition in a developer.

  Examples of the optionally substituted alkyl group include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group, and a 1-hydroxy group. C1-C4 hydroxyalkyl groups such as butyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group; methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n- C1-C4 alkoxyl groups such as butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group; cyano group; cyanomethyl group, 2-cyanoethyl group, 3-cyanopropyl group, 4-cyanobutyl And groups having at least one substituent such as a cyanoalkyl group having 2 to 5 carbon atoms such as a group. . Among these, a hydroxymethyl group, a cyano group, and a cyanomethyl group are preferable.

  Examples of the optionally substituted aryl group include a phenyl group, a benzyl group, a phenylethyl group, a phenylpropyl group, and a phenylcyclohexyl group. These compounds are substituted with a hydroxyl group, a cyano group, or the like. Can be mentioned. Among these, a phenyl group, a benzyl group, and a phenylcyclohexyl group are preferable.

  Specific examples of the acid diffusion controller (b) include, for example, triphenylsulfonium hydroxide, triphenylsulfonium acetate, triphenylsulfonium salicylate, diphenyl-4-hydroxyphenylsulfonium hydroxide, diphenyl-4-hydroxyphenylsulfonium. Sulfonium salt compounds such as acetate, diphenyl-4-hydroxyphenylsulfonium salicylate, triphenylsulfonium 1-adamantane carboxylate, triphenylsulfonium 10-camphorsulfonate, 4-t-butoxyphenyl diphenylsulfonium 10-camphorsulfonate; and

Bis (4-t-butylphenyl) iodonium hydroxide, bis (4-t-butylphenyl) iodonium acetate, bis (4-t-butylphenyl) iodonium hydroxide, bis (4-t-butylphenyl) iodonium acetate, Bis (4-t-butylphenyl) iodonium salicylate, 4-t-butylphenyl-4-hydroxyphenyliodonium hydroxide, 4-t-butylphenyl-4-hydroxyphenyliodonium acetate, 4-t-butylphenyl- 4-hydroxyphenyliodonium salicylate, bis (4-t-butylphenyl) iodonium 1-adamantanecarboxylate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate, diphenyl Can be mentioned Doniumu 10 iodonium salt compounds such as camphorsulfonate, it may be used either individually or in combination.

  Examples of the acid diffusion control agent (C) other than the acid diffusion control agents (a) and (b) include tertiary amine compounds, quaternary ammonium hydroxide compounds, and other nitrogen-containing heterocyclic compounds.

  Examples of tertiary amine compounds include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octyl. Tri (cyclo) alkylamines such as amine, cyclohexyldimethylamine, dicyclohexylmethylamine, tricyclohexylamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methyl Aromatic amines such as aniline, 4-nitroaniline, 2,6-dimethylaniline and 2,6-diisopropylaniline; alkanolamines such as triethanolamine and N, N-di (hydroxyethyl) aniline; N, N , N ′, N′-Tetramethyl Tylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzenetetramethylenediamine, bis (2 Mention may be made of -dimethylaminoethyl) ether and bis (2-diethylaminoethyl) ether.

  Examples of the quaternary ammonium hydroxide compound include tetra-n-propylammonium hydroxide and tetra-n-butylammonium hydroxide.

  Examples of the nitrogen-containing heterocyclic compound include: pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenyl. Pyridines such as pyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline and acridine; piperazines such as piperazine and 1- (2-hydroxyethyl) piperazine, as well as pyrazines and pyrazoles , Pyridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane, Imidazole, 4-methylimida Lumpur, 1-benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, mention may be made of benzimidazole and 2-phenylbenzimidazole.

  These acid diffusion control agents (C) containing these acid diffusion control agents (a) can be used alone or in admixture of two or more.

  In the present invention, the total amount of the acid diffusion control agent (C) used is preferably less than 10 parts by mass and less than 5 parts by mass with respect to 100 parts by mass of the resin (A) from the viewpoint of ensuring high sensitivity as a resist. Is more preferable. In this case, when the total usage exceeds 10 parts by mass, the sensitivity as a resist tends to be remarkably lowered. In addition, if the usage-amount of an acid diffusion control agent (C) is less than 0.001 mass part, there exists a possibility that the pattern shape and dimension fidelity as a resist may fall depending on process conditions.

  In addition, the alicyclic additive having an acid dissociable group is a component having an action of further improving dry etching resistance, pattern shape, adhesion to a substrate, and the like. Examples of such alicyclic additives include 1-adamantanecarboxylate t-butyl, 1-adamantanecarboxylate t-butoxycarbonylmethyl, 1,3-adamantanedicarboxylate di-t-butyl, 1-adamantaneacetic acid. adamantane derivatives such as t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl and 1,3-adamantanediacetate di-t-butyl; deoxycholate t-butyl, deoxycholate t-butoxycarbonylmethyl, deoxychol Deoxycholic acid esters such as 2-ethoxyethyl acid, 2-cyclohexyloxyethyl deoxycholic acid, 3-oxocyclohexyl deoxycholic acid, tetrahydropyranyl deoxycholic acid and mevalonolactone ester deoxycholic acid; And lithocholic acid esters such as lithocholic acid t-butoxycarbonylmethyl, lithocholic acid 2-ethoxyethyl, lithocholic acid 2-cyclohexyloxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl and lithocholic acid mevalonolactone ester Can be mentioned. In addition, these alicyclic additives can be used individually or in mixture of 2 or more types.

  Further, the surfactant is a component having an action of improving applicability, striation, developability and the like. Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. And nonionic surfactants such as polyethylene glycol distearate. Moreover, as a commercial item, all the following brand names are KP341 (made by Shin-Etsu Chemical Co., Ltd.), polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), Ftop EF301, EF303, EF352 (manufactured by Tochem Products), Megafax F171, F173 (manufactured by 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 and SC-106 (Asahi Glass Co., Ltd.) Can do. In addition, these surfactant can be used individually or in mixture of 2 or more types.

<Method for forming photoresist pattern>:
The radiation sensitive resin composition of this embodiment is particularly useful as a chemically amplified resist. For example, in the case of a positive resist, when a resist film is formed with the radiation-sensitive resin composition of the present embodiment, an acid generated from the acid generator represented by the general formula (1) described above by exposure (other acid generation) When an agent is blended, the acid-dissociable group in the resin having a repeating unit is dissociated by the action of an acid generated from other acid generators) to generate a carboxyl group. The solubility of the exposed portion with respect to the alkaline developer is increased, and this exposed portion is dissolved and removed by the alkaline developer to obtain a positive resist pattern.

  When forming a resist pattern from the radiation-sensitive resin composition of the present embodiment, first, the above-mentioned acid generator and, if necessary, the above-mentioned other acid generator and the resin having the above repeating unit are used as the solvent. The composition solution can be obtained by, for example, filtering it through a filter having a pore size of about 200 nm after being uniformly dissolved in the solution. In addition, the amount of the solvent at this time is preferably such an amount that the concentration of the total solids is 0.1 to 50% by mass, and more preferably 1 to 40% by mass. . By setting it as such a density | concentration, filtration can be performed smoothly.

  Next, the obtained composition solution is applied onto a substrate such as a silicon wafer or a wafer coated with aluminum by an appropriate application means such as spin coating, cast coating, or roll coating. A resist film is formed. Thereafter, in some cases, after heat treatment (hereinafter referred to as “SB”) in advance, the resist film is exposed to form a predetermined resist pattern. In addition, visible rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams and the like are appropriately selected and used as the radiation used at that time, but ArF excimer laser (wavelength 193 nm) or KrF excimer laser (wavelength Far ultraviolet rays represented by 248 nm) are preferable, and ArF excimer laser (wavelength 193 nm) is particularly preferable. Further, it is preferable to perform a heat treatment (hereinafter referred to as “PEB”) after exposure. By this PEB, the dissociation reaction of the acid dissociable group in the resin proceeds smoothly. The heating conditions for PEB vary depending on the composition of the radiation-sensitive resin composition, but are preferably 30 to 200 ° C, and more preferably 50 to 170 ° C.

  The radiation-sensitive resin composition of the present embodiment has an organic system on the substrate to be used, for example, as disclosed in Japanese Patent Publication No. 6-12452, etc., in order to maximize the potential. Alternatively, an inorganic antireflection film can be formed. Further, in order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film can be provided on the resist film as disclosed in, for example, JP-A-5-188598. These techniques can be used in combination.

  Next, the exposed resist film is developed to form a predetermined resist pattern. Examples of the developer used for development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propylamine. , Triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene and 1,5-diazabicyclo- [4.3.0] An alkaline aqueous solution in which at least one of alkaline compounds such as 5-nonene is dissolved is preferable. The concentration of the alkaline aqueous solution is preferably 10% by mass or less. If the concentration of the alkaline aqueous solution is more than 10% by mass, the unexposed area may be dissolved in the developer.

  Further, for example, an organic solvent can be added to the developer. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone and 2,6-dimethylcyclohexanone; methyl alcohol, ethyl alcohol, n-propyl Alcohols such as alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol and 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane Esters such as ethyl acetate, n-butyl acetate and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonyl acetone and dimethylformamide; Can.

In addition, these organic solvents can be used individually or in mixture of 2 or more types.
It is preferable that the usage-amount of an organic solvent is 100 volume% or less with respect to the said alkaline aqueous solution. If the amount of the organic solvent used is more than 100% by volume, the developability is lowered, and there is a risk that the remaining development in the exposed area will increase. An appropriate amount of a surfactant or the like can be added to the developer. In addition, after developing with the said developing solution, it is preferable to wash | clean and dry with water.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

  The sensitivity, MEEF, and LWR of the radiation sensitive resin compositions obtained in the examples and comparative examples were evaluated as follows.

[sensitivity]:
Regarding the examples and comparative examples, a substrate having a 77 nm ARC29A (Nissan Chemical) film formed on the wafer surface was used, and the composition was applied onto the substrate by spin coating. The resist film having a thickness of 120 nm formed by performing SB for 90 seconds was exposed through a mask pattern using a full-field reduction projection exposure apparatus “S306C” (numerical aperture: 0.78) manufactured by Nikon Corporation. Thereafter, PEB was performed at the temperature shown in Table 2 for 90 seconds, and then developed with a 2.38 mass% TMAH aqueous solution at 25 ° C. for 60 seconds, washed with water, and dried to form a positive resist pattern. At this time, the exposure amount (mJ / cm ² ) formed in a one-to-one line and space with a line width of 90 nm is defined as an optimum exposure amount through a mask with a one-to-one line and space with a dimension of 90 nm. The optimum exposure amount (mJ / cm ² ) was defined as “sensitivity”.

[LWR]:
When observing the 90 nm 1L / 1S pattern resolved at the optimum exposure dose, when observing from the top of the pattern with Hitachi SEM: S9220, the line width was observed at 10 arbitrary points, and the measurement variation was 3 The value expressed in sigma was defined as LWR. It shows that roughness is excellent, so that the value of LWR is low.

[MEEF]:
The optimal exposure dose sensitivity was measured using a mask having a line width of 90 nm so that the line width of the 90 nm 1L / 1S pattern was 90 nm, and then the sensitivity was 85.0 nm, 87.5 nm, 90.0 nm, 92. Pattern dimensions resolved at mask sizes at 5 points of 5 nm and 95.0 nm were measured. The result was taken as the mask size on the horizontal axis and the line width on the vertical axis, and the gradient obtained by the least square method was defined as MEEF.

<Example of resin synthesis>
The following compound (S-1) 37.28 g (40 mol%), the following compound (S-2) 18.50 g (15 mol%), the following compound (S-3) 44.22 g (45 mol%) A monomer solution was prepared by dissolving in 200 g of butanone and adding 4.83 g of dimethyl 2,2′-azobis (isobutyrate). A 1000 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 in advance was added using a dropping funnel. The solution was added dropwise over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling, charged into 2000 g of n-heptane, and the precipitated white powder was separated by filtration.
The filtered white powder was dispersed in 400 g of n-heptane, washed in the form of a slurry, washed twice, and then dried at 50 ° C. for 17 hours to obtain a white powder copolymer ( Resin (B-1)) was obtained. This copolymer has Mw of 9000 and Mw / Mn = 1.7. As a result of ¹³ C-NMR analysis, this copolymer is represented by compound (S-1), compound (S-2), and compound (S-3). The content of each repeating unit was 45.4: 11.3: 43.3 (mol%). This copolymer is referred to as “polymer (B-1)”.

100 parts of the obtained polymer (B-1), 10.1 parts of the following radiation sensitive acid generator (acid generator) (A-1), and 0.6 parts of the following acid diffusion controller (C) are mixed. As a result, a radiation sensitive resin composition was obtained. The radiation sensitive resin composition obtained by 1880 parts of the following solvent (D-1) was melt | dissolved, and the radiation sensitive resin composition solution was obtained. In addition, the compounding quantity of each solvent is shown by the mass ratio (mass part) with respect to 100 parts of polymers (B). Using the obtained radiation-sensitive resin composition solution, the results of the above evaluations at SB = 100 ° C. and PEB = 115 ° C. show that the sensitivity is 38.0 mJ / cm ² and the LWR is 7.2 nm. Yes, the MEEF was 3.0.

Radiation sensitive acid generator (A);

Acid diffusion controller (C);
(C-1); trioctylamine (C-2); Nt-butoxycarbonyl-4-hydroxypiperidine (C-3): 2-phenylbenzimidazole (C-4): triphenylsulfonium salicylate

Solvent (D);
(D-1): Propylene glycol monomethyl ether acetate (D-2): Cyclohexanone (D-3): γ-butyrolactone

  The polymer (resin (B)) (B-2 to 4) is converted into a polymer (B) with the molar ratio of the compound (S-1), etc. shown in the following “copolymer (resin (B))”. -1), the polymer (B-5 to 11) was prepared in the same manner as the polymer (B-1) except that heptane was changed to methanol. Each of (B-2 to 11), the radiation-sensitive acid generator (A), and the acid diffusion controller (C) were mixed in the ratios shown in Table 1 in the same manner as in Example 1. The radiation sensitive resin composition (Examples 2-18, Comparative Examples 1-10) was produced. The obtained radiation sensitive resin composition was dissolved in a mixed solvent in which the solvent (D) was mixed at a mixing ratio shown in Table 1 to obtain a radiation sensitive resin composition solution. In Table 1, “resin” means “copolymer (resin (B))”. Each measurement was performed using the obtained radiation-sensitive resin composition solution. The measurement results are shown in Table 2.

Copolymer (resin (B));
B-2: (S-1) 40 / (S-2) 15 / (S-5) 45 = 41.0 / 12.8 / 46.2 (molar ratio), Mw = 10500, Mw / Mn = 1 .7
B-3: (S-1) 40 / (S-3) 30 / (S-5) 30 = 43.2 / 27.8 / 29.0 (molar ratio), Mw = 6000, Mw / Mn = 1 .4
B-4: (S-1) 40 / (S-3) 60 = 56.2 / 53.8 (molar ratio), Mw = 4000, Mw / Mn = 1.4
B-5: (S-1) 40 / (S-4) 60 = 58.2 / 51.8 (molar ratio), Mw = 4000, Mw / Mn = 1.4
B-6: (S-1) 50 / (S-3) 25 / (S-6) 25 = 54.9 / 25.4 / 19.6 (molar ratio), Mw = 6000, Mw / Mn = 1 .7
B-7: (S-1) 50 / (S-5) 25 / (S-7) 25 = 53.5 / 23.9 / 22.6 (molar ratio), Mw = 7000, Mw / Mn = 1 .3
B-8: (S-1) 50 / (S-5) 50 = 49.1 / 50.9 (molar ratio), Mw = 7000, Mw / Mn = 1.7
B-9: (S-1) 50 / (S-6) 50 = 48.6 / 51.4 (molar ratio), Mw = 7000, Mw / Mn = 1.7
B-10: (S-1) 40 / (S-4) 10 / (S-5) 40 / (S-8) 10 = 33.7 / 12.8 / 9.6 / 43.8 (molar ratio) ), Mw = 6000, Mw / Mn = 1.5
B-11: (S-1) 40 / (S-5) 60 = 43.1 / 56.9 (molar ratio), Mw = 7000, Mw / Mn = 1.4

  From Table 2, it can be seen that any of the compositions of the present invention is superior in MEEF compared to the composition of the comparative example.

  The present invention is extremely suitable as a radiation sensitive resin composition useful as a chemically amplified resist. The radiation-sensitive composition of the present invention is used in a lithography process using an ArF excimer laser as a light source, particularly as a chemically amplified resist having an appropriate sensitivity and excellent LWR and MEEF in forming a fine pattern of 90 nm or less. Can be used.

Claims (5)

(A) and a sulfonic acid salt or sulfo Niruokishi group-containing radiation-sensitive acid generator having a partial structure represented by the following general formula (1), (B) a radiation-sensitive resin composition containing the resin.

[In General Formula (1), R ¹ represents a substituted or unsubstituted linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms, a substituted or unsubstituted cyclic or cyclic group having 3 to 30 carbon atoms. A monovalent hydrocarbon group having the following partial structure, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a cyclic group which may have a substituted or unsubstituted monovalent hetero atom having 4 to 30 carbon atoms An organic group is shown. ] The radiation sensitive resin composition according to claim 1, wherein the (A) radiation sensitive acid generator is a compound represented by the following general formula (2).

[In the general formula (2), R ¹ represents a substituted or unsubstituted linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms, a substituted or unsubstituted cyclic group having 3 to 30 carbon atoms, or A monovalent hydrocarbon group having a cyclic partial structure, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a cyclic group optionally having a substituted or unsubstituted monovalent heteroatom having 4 to 30 carbon atoms An organic group is shown. M ⁺ represents a monovalent onium cation. ] The radiation sensitive resin composition according to claim 2, wherein M ⁺ is a sulfonium cation or an iodonium cation represented by the following general formula (3) or (4).

[In General Formula (3), R ² , R ³ , and R ⁴ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted carbon. The aryl group of formula 6-18 is shown, or any two or more of R ² , R ³ and R ⁴ are bonded to each other to form a ring together with the sulfur atom in the formula. ]

[In the general formula (4), R ⁵ and R ⁶ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted carbon group having 6 to 18 carbon atoms. Or R ⁵ and R ⁶ are bonded to each other to form a ring together with the iodine atom in the formula. ] The radiation sensitive resin composition according to claim 1, wherein the (A) radiation sensitive acid generator is a compound represented by the following general formula (5).

[In the general formula (5), R ¹ represents a substituted or unsubstituted linear or branched monovalent hydrocarbon group having 1 to 30 carbon atoms, a substituted or unsubstituted cyclic group having 3 to 30 carbon atoms, or A monovalent hydrocarbon group having a cyclic partial structure, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a cyclic group optionally having a substituted or unsubstituted monovalent heteroatom having 4 to 30 carbon atoms An organic group is shown. R ⁷ and R ⁸ each independently represent a hydrogen atom or a substituted or unsubstituted monovalent organic group, or R ⁷ and R ⁸ form a ring together with the carbon atoms to which R ⁷ and R ⁸ are bonded to each other; Y represents a single bond, a double bond or a divalent organic group. ] The radiation sensitive resin composition of Claim 1 in which the said (B) resin contains the repeating unit represented by following General formula (6).

[In the general formula (6), each R ⁹ independently represents hydrogen, a methyl group or a trifluoromethyl group, R ′ represents a linear alkyl group or a branched alkyl group having 1 to 4 carbon atoms, and each R represents Independently represents a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or two R's are bonded to each other to bond A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms is formed together with the carbon atoms. ]