JP2007052182A - Radiation sensitive resin composition - Google Patents

Abstract

Disclosed is a radiation-sensitive resin composition that is a resist that is excellent in sensitivity and resolution, has a small line edge roughness of a pattern, and can maintain a good pattern shape.
A radiation sensitive composition comprising (A) an acid-dissociable group-containing copolymer containing an alkyl-substituted norbornanelactone ring, (B) a sulfonic acid ester-type acid proliferating agent, and (C) an acid generator. Resin composition.
[Selection figure] None

Description

  The present invention relates to a radiation-sensitive resin composition, and more specifically, various radiations such as deep ultraviolet rays such as KrF excimer laser or ArF excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams are used. The present invention relates to a radiation sensitive resin composition that can be suitably used as a chemically amplified resist useful for fine processing.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm) or the like is used. There is a need for a lithography technique capable of microfabrication at the same level. As a radiation-sensitive resin composition suitable for irradiation with such an excimer laser, a chemistry utilizing the chemical amplification effect of a component having an acid dissociable functional group and an acid generator that is a component that generates an acid upon irradiation with radiation. Many amplified radiation-sensitive compositions have been proposed. For example, a high-molecular compound for photoresist using a polymer having a specific structure including a monomer unit having a norbornane ring derivative as a resin component is known (see Patent Document 1 and Patent Document 2). Moreover, in order to improve sensitivity and resolution, a radiation sensitive resin composition is disclosed in which a photoactive compound is further added to a component having an acid dissociable functional group and an acid generator (see Patent Document 3).

However, when a higher degree of integration is required in the semiconductor field, the radiation-sensitive resin composition that is a resist is required to have better sensitivity and resolution. At the same time, as the miniaturization progresses, the demand for reducing the line edge roughness (LER) of the pattern and further the demand for maintaining a good pattern shape have increased. With the advancement of miniaturization in the semiconductor industry, there is an urgent need to develop a radiation-sensitive resin composition that satisfies such conditions as excellent sensitivity and resolution, low pattern line edge roughness, and good pattern shape. It has become.
JP 2002-201232 A JP 2002-145955 A JP 2002-363123 A

  An object of the present invention is to provide a radiation-sensitive resin composition which is a chemically amplified resist that is excellent in sensitivity and resolution, has a small pattern line edge roughness, and can maintain a good pattern shape. is there.

  The radiation-sensitive resin composition of the present invention that solves the above problems is as follows.

〔一般式（１−１）において、Ｒ¹は水素原子、メチル基、またはトリフルオロメチル基、Ｚは酸の作用により脱離可能な保護基を示す。一般式（１−２）において、Ｒ¹は水素原子、メチル基、またはトリフルオロメチル基を表し、Ｒ²は相互に独立に、水素原子、炭素数１〜４の直鎖状あるいは分岐状のアルキル基、炭素数１〜４の直鎖状あるいは分岐状のアルコキシ基、または、炭素数１〜４の直鎖状あるいは分岐状のフッ素化アルキル基を表す。ｍは０〜３の整数である。一般式（１−３）において、Ｒ³、Ｒ⁴は相互に独立に水素原子、フッ素原子、炭素数１〜４の直鎖状もしくは分岐のアルキル基、パーフルオロアルキル基を示す。ｎは１〜８の整数を、Ａは酸解離性基を示し、Ｇはフッ素原子又は一価の有機基を表す。〕 [1] (A) An acid dissociable group-containing polymer having a repeating unit represented by the following general formula (1-1) and a repeating unit represented by the following general formula (1-2), and (B) the following general formula A radiation-sensitive resin composition containing the compound represented by (1-3) and (C) an acid generator that generates an acid upon irradiation with radiation.

[In the general formula (1-1), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and Z represents a protective group that can be removed by the action of an acid. In General Formula (1-2), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² is independently a hydrogen atom, a linear or branched group having 1 to 4 carbon atoms. An alkyl group, a linear or branched alkoxy group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms is represented. m is an integer of 0-3. In General Formula (1-3), R ³ and R ⁴ each independently represent a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a perfluoroalkyl group. n represents an integer of 1 to 8, A represents an acid dissociable group, and G represents a fluorine atom or a monovalent organic group. ]

〔一般式（１−４）において、Ｒ¹は水素原子、メチル基、またはトリフルオロメチル基、Ｘは、炭素数４〜２０の置換若しくは非置換の多環型脂環式炭化水素基を表す。〕 [2] The radiation sensitive resin composition according to [1], wherein the (A) acid dissociable group-containing polymer further has a repeating unit represented by the following general formula (1-4).

[In General Formula (1-4), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and X represents a substituted or unsubstituted polycyclic alicyclic hydrocarbon group having 4 to 20 carbon atoms. . ]

[3] The radiation sensitive resin composition according to [1] or [2], wherein in the general formula (1-3), R ³ and R ⁴ are fluorine atoms.

  The radiation-sensitive resin composition of the present invention is a chemically amplified resist that is sensitive to actinic radiation, particularly far ultraviolet rays typified by ArF excimer laser (wavelength 193 nm), and has an excellent balance of characteristics such as sensitivity to radiation and resolution. In addition, the resist pattern shape after development is good, and the line edge roughness of the pattern can be reduced.

  Next, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail, but the present invention is not limited to the following embodiment, and the gist of the present invention is described below. It should be understood that design changes, improvements, and the like can be made as appropriate based on ordinary knowledge of those skilled in the art without departing from the scope.

(Radiation sensitive resin composition)
The radiation-sensitive resin composition of this embodiment has (A) a repeating unit having an acid dissociable group represented by the following general formula (1-1) and a repeating unit represented by the following general formula (1-2). Then, an alkali-insoluble or alkali-insoluble acid-dissociable group-containing polymer (hereinafter sometimes referred to as “(A) polymer”) that becomes alkali-soluble by the action of an acid, and (B) the following general formula (1) -3) (hereinafter sometimes referred to as “(B) compound”) and (C) an acid generator that generates an acid upon irradiation with radiation (hereinafter referred to as “(C) acid generator”). And so on).

In the general formula (1-1), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and Z represents a protective group that can be removed by the action of an acid. In General Formula (1-2), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² is independently a hydrogen atom, a linear or branched group having 1 to 4 carbon atoms. An alkyl group, a linear or branched alkoxy group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms is represented. m is an integer of 0-3. In General Formula (1-3), R ³ and R ⁴ each independently represent a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a perfluoroalkyl group. n represents an integer of 1 to 8, A represents an acid dissociable group, and G represents a fluorine atom or a monovalent organic group.

  Since the radiation sensitive resin composition of this embodiment contains (B) compound and (C) acid generator as mentioned above, it is used as a chemically amplified resist and (C) acid is irradiated by radiation. When the acid is generated from the generator, (C) the compound (B) is decomposed by the action of the acid generated from the acid generator, and more acid is generated. A large amount of acid can be generated. Thus, by generating a large amount of acid over the entire irradiated portion of the resist, (A) the acid dissociable group of the polymer can be dissociated more uniformly over the entire irradiated portion of the resist. In particular, the line edge roughness of the pattern after development can be reduced.

((A) polymer)
The polymer (A) contained in the radiation-sensitive resin composition of the present embodiment is a repeating unit represented by the general formula (1-1) having an acid dissociable group (hereinafter referred to as “(1-1) repeating”). And a repeating unit represented by the above general formula (1-2) containing a lactone skeleton (hereinafter, also referred to as “(1-2) repeating unit”). It is a coalescence. (1-1) The repeating unit is an alkali-insoluble or hardly alkali-soluble repeating unit, but has an acid-dissociable group, and therefore exhibits alkali-solubility after the acid-dissociable group is dissociated by the action of an acid. . In the general formula (1-1), the acid dissociable group is a carboxyl group protected by a protecting group Z.

In the general formula (1-1), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and Z represents a protective group that can be removed by the action of an acid. The repeating unit having an acid dissociable group represented by the general formula (1-1) is preferably a repeating unit represented by the following general formula (2) or (3).

〔式（２）および式（３）において、Ｒ⁵およびＲ⁹は水素原子、メチル基、またはトリフルオロメチル基をそれぞれ表し、Ｒ⁶およびＲ⁷は相互に独立に炭素数１〜４の直鎖状または分岐状のアルキル基を、Ｒ⁸は炭素数４〜２０の脂環式炭化水素基をそれぞれ表し、Ｒ¹⁰は炭素数１〜４の直鎖状または分岐状のアルキル基を、Ｒ¹¹およびＲ¹²は相互に独立に水素原子、または炭素数１〜４の直鎖状または分岐状のアルキル基をそれぞれ表し、ｎは３〜７の整数を表す。〕

[In the formulas (2) and (3), R ⁵ and R ⁹ each represent a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁶ and R ⁷ are each independently a straight chain having 1 to 4 carbon atoms. A chain or branched alkyl group, R ⁸ represents an alicyclic hydrocarbon group having 4 to 20 carbon atoms, R ¹⁰ represents a linear or branched alkyl group having 1 to 4 carbon atoms, R ¹¹ and R ¹² each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and n represents an integer of 3 to 7. ]

R ⁶ and R ⁷ in the formula (2) are, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t- A butyl group etc. are mentioned. Examples of R ⁸ include cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, and tricyclo [5.2.1.0 ² ]. ^{, 6} ] decane, tetracyclo [4.4.0.1 ^2,6 . 1 ^7,10 ] dodecane, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecane, or hydrocarbon groups derived from these derivatives. Examples of R ⁵ include a hydrogen atom, a methyl group, and a trifluoromethyl group.

As R < ¹⁰ > in Formula (3), a methyl group, an ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group etc. are mentioned, for example. Is mentioned. R ¹¹ and R ¹² are, for example, a hydrogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl. Groups and the like. Examples of R ⁹ include a hydrogen atom, a methyl group, and a trifluoromethyl group.

In the formula (3), it is particularly preferable that R ¹⁰ is a methyl group or an ethyl group, R ¹¹ and R ¹² are hydrogen atoms, and n is 4 or 5. Particularly preferred examples are listed in the following formulas (3-1) to (3-4).

  In formulas (3-1) to (3-4), R represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

  (A) The polymer may have one or more types of repeating units represented by the above formulas (2) and (3) as (1-1) repeating units. Good.

When R ² in the lactone skeleton-containing repeating unit represented by the general formula (1-2) is a linear or branched alkyl group having 1 to 4 carbon atoms, specific examples thereof include, for example, methyl Group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, etc., straight chain having 1 to 4 carbon atoms In the case of a branched alkoxy group, specific examples thereof include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t -Butoxy group etc. are mentioned. When R ² is a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms, specific examples thereof include a group in which part or all of the hydrogen of the alkyl group is substituted with a fluorine atom. It is done. The lactone skeleton preferably has one or more of these substituents.

(1-1) The repeating unit is preferably a repeating unit derived from the monomer shown below in addition to the repeating units represented by the above formulas (2) and (3). As the monomer, (meth) acrylic acid 2-methyladamantan-2-yl ester, (meth) acrylic acid 2-ethyladamantan-2-yl ester, (meth) acrylic acid 2-n-propyl adamantane- 2-yl ester, (meth) acrylic acid 2-isopropyladamantan-2-yl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 2-methylbicyclo [2.2.1] Hept-2-yl ester, (meth) acrylic acid 2-ethylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid 8-methyltricyclo [5. 2.1.0 ^2,6 ] dec-8-yl ester, (meth) acrylic acid 8-ethyltricyclo [5.2.1.0 ^2,6 ] dec-8-yl ester, (Meth) acrylic acid 4-methyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-yl ester, (meth) acrylic acid 4-ethyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-yl ester, (meth) acrylic acid 1- (tetracyclo [6.2.1.1 ^3,6 .0 ^2,7 ] dodec-4-yl) -1-methylethyl ester , (Meth) acrylic acid 1,1-dicyclohexyl ethyl ester and other monomers having an acid dissociable group.

  (A) In the polymer, the content (molar ratio) of (1-1) repeating units is the sum of (1-1) repeating units and (1-2) repeating units (hereinafter referred to as “two types of repeating units”). Is sometimes referred to as “total of units”.) Is 100 mol%, it is preferably 10 to 90 mol%, and more preferably 30 to 80 mol%. By setting the two types of repeating units in such a range, an appropriate dissolution contrast can be obtained, and an excellent pattern profile with good sensitivity, resolution, and low LER can be obtained. And (1-1) If the content rate of the repeating unit is too small, there is a possibility that the pattern profile is not formed due to a decrease in dissolution contrast. (1-1) If the content rate of the repeating unit is too large, appropriate dissolution There is a possibility that the contrast cannot be obtained and the resolution is lowered. Furthermore, if the content of the repeating unit (1-2) is too small, a good pattern profile may not be formed due to a decrease in dissolution contrast, and (1-2) if the content of the repeating unit is too large, A) The solubility of the polymer in the solvent may decrease.

〔一般式（１−４）において、Ｒ¹は水素原子、メチル基、またはトリフルオロメチル基、Ｘは、炭素数４〜２０の置換若しくは非置換の多環型脂環式炭化水素基をあらわす。〕 It is preferable that the (A) polymer contained in the radiation sensitive resin composition of this embodiment further has a repeating unit represented by the following general formula (1-4).

[In General Formula (1-4), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and X represents a substituted or unsubstituted polycyclic alicyclic hydrocarbon group having 4 to 20 carbon atoms. . ]

  In the above general formula (1-4), X is a substituted or unsubstituted polycyclic alicyclic hydrocarbon group having 4 to 20 carbon atoms. The unsubstituted polycyclic alicyclic hydrocarbon group is preferably a polycyclic alicyclic hydrocarbon group consisting of only carbon atoms and hydrogen atoms. In addition, as the substituted polycyclic alicyclic hydrocarbon group, a group in which a part of hydrogen atoms bonded to the carbon atom forming the ring structure of the polycyclic alicyclic hydrocarbon group is substituted with a hydroxyl group (Hereinafter sometimes referred to as “OH-substituted polycyclic alicyclic hydrocarbon group”). In addition, the substituent represented by X does not leave by the action of an acid.

Examples of the polycyclic alicyclic hydrocarbon group include bicyclo [2.2.1] heptane (1a) and bicyclo [2.2.2] as shown in the following formulas (4a) to (4e). Octane (1b), tricyclo [5.2.1.0 ^2,6 ] decane (1c), tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] hydrocarbon groups composed of alicyclic rings derived from cycloalkanes such as dodecane (4d) and adamantane (4e).

  These cycloalkane-derived alicyclic hydrocarbon groups may have a substituent. Preferable substituents include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like. 4 linear, branched or cyclic alkyl groups, and the like, and alicyclic rings having one or more of these as substituents are also preferred. For example, these are represented by the specific examples shown in the following formulas (4f) to (4l), but are not limited thereto. These may be used alone or in combination of two or more.

  In the general formula (1-4), when X is an OH-substituted polycyclic alicyclic hydrocarbon group having 4 to 20 carbon atoms, the repeating unit (1-4) is as follows. The hydroxyadamantane group containing repeating unit represented by General formula (4) can be mentioned.

  In General formula (4), R is a hydrogen atom, a methyl group, or a trifluoromethyl group, p is an integer of 1-3. The position of the adamantane skeleton to which the hydroxyl group is bonded is preferably the 3rd position.

  (A) In the polymer, the content (molar ratio) of (1-4) repeating units is the sum of (1-1) repeating units, (1-2) repeating units and (1-4) repeating units. When it is defined as mol%, it is preferably 0 to 50 mol%, and more preferably 0 to 30 mol%. (1-4) If the content of the repeating unit is too small, an appropriate dissolution contrast may not be obtained and the resolution may be lowered. (1-4) If the content of the repeating unit is too large, Solubility may decrease, and sensitivity and pattern profile may decrease.

  In this embodiment, (A) polymer can be used individually or in mixture of 2 or more types. Further, the polymer (A) is alkali-insoluble or hardly alkali-soluble, but the acid-dissociable group of the (1-1) repeating unit is dissociated by the action of an acid, and becomes alkali-soluble.

((B) Compound)
The compound (B) contained in the radiation sensitive resin composition of the present embodiment is an acid proliferating agent represented by the above general formula (1-3). The acid proliferating agent is decomposed by the action of the primary (existing) acid to secondaryly generate more acid than the temporarily generated acid, and as a whole, more (at least It is a compound capable of generating an acid (more than the temporarily generated acid). As described above, the radiation-sensitive resin composition of the present embodiment generates a large amount of acid over the entire irradiated portion of the resist by decomposing the compound (B) and generating more acid. Is possible. Thus, by generating a large amount of acid over the entire irradiated portion of the resist, (A) the acid dissociable group of the polymer can be dissociated more uniformly over the entire irradiated portion of the resist. In particular, the line edge roughness of the pattern after development can be reduced.

  Hereinafter, the acid proliferating agent will be described in more detail. In the photosensitive composition (photosensitive resin) used in the method for forming a fine pattern of the present invention, a compound that decomposes in the presence of an acid catalyst and generates a new acid molecule (acid proliferating agent) has a molecular structure. It is characterized by using a compound that does not contain an aromatic ring. In other words, the acid proliferating agent used in the method for forming a fine pattern of the present invention includes an acid residue, hydrogen, and at least one of aliphatic, alicyclic, condensed alicyclic, heterocyclic and derivatives thereof. It is characterized by using a structured compound. Examples of such a compound (acid proliferating agent) include various compounds, and a sulfonic acid ester compound represented by the following general formula (5) is preferable.

In the general formula (5), R ³ and R ⁴ each independently represent a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a perfluoroalkyl group. n represents an integer of 1 to 8, and G represents a fluorine atom or a monovalent organic group. A ¹ to A ^{3 in} the general formula (5) may be the same or different and each represents an independent hydrogen atom or a monovalent organic group not containing an aromatic ring structure. Examples of the monovalent organic group include substituted or unsubstituted chain alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, and isopentyl, cyclopropyl, cyclobutyl, piperidyl and the like. And substituted or unsubstituted aliphatic rings or heterocyclic rings such as tetrahydrofuranyl and pyranyl. At this time, a ring containing carbon atoms to which two members selected from A ¹ to A ³ are bonded may be formed.

The acid proliferator decomposes in the presence of an acid catalyst to generate a compound (JSO ₃ H) having an acid dissociation constant (PKa) of 3 or less (J is (CR ^{3 in} formula (1-3)). R ⁴ ) represents an _n G group). The acid has an acid dissociation constant (Pka) of 3 or less, more preferably an acid dissociation constant of 2 or less. This is because a weaker acid cannot effectively act as a catalyst for promoting the decomposition reaction of the acid proliferating agent.

The compound represented by the general formula (5) is a sulfonic acid ester compound, a hydroxyl group is easily eliminated by the action of an acid catalyst to form a carbon cation, and the sulfonic acid compound (JSO ₃ H) is converted by hydrogen transfer. generate. Since the elimination reaction can be greatly activated by the presence of the acid catalyst, it is stable in the absence of the acid catalyst, but in the presence of the acid catalyst, it is possible to easily generate an acid by a thermochemical reaction. . At this time, since a new acid is generated by a reaction that is decomposed by the acid catalyst reaction, one or more acids are increased in one reaction, and the acid generated by the acid catalyst reaction itself becomes a catalyst for the next reaction. Therefore, the acid-catalyzed reaction proceeds at an accelerated rate as the reaction proceeds.

Further, the generated sulfonic acid compound (JSO ₃ H) must have an aromatic ring in its structure in order to have transparency at an exposure wavelength of a short wavelength such as ArF excimer laser light. Examples of structures suitable as such sulfonic acid compounds (JSO ₃ H) are shown in the following chemical formulas (5-1) to (5-9), but are not limited thereto. In addition, n in a formula represents the integer of 1-8.

  In these structures, some or all of the hydrogen atoms are substituted with halogen atoms, nitro groups, hydroxyl groups, methyl, ethyl, normal propyl, isopropyl, normal butyl, isobutyl, tertiary butyl, pentyl, isopentyl, etc. It may be replaced with a cyclic alkyl group such as an unsubstituted chain alkyl group, cyclohexyl, menthyl, norbornyl, isobornyl, adamantyl and the like. Particularly, by substituting part or all of the hydrogen of the alkyl group of the general formula (5-3) with a halogen atom such as a fluorine atom, there is an effect that the acid dissociation constant of the sulfonic acid compound to be produced is increased. Particularly preferred.

  Moreover, many advantages can be obtained by having one or more aliphatic rings, particularly condensed aliphatic rings, in the structure of the compound molecule represented by the general formula (5). Such advantages include, for example, improved thermal stability of the acid proliferator, improved heat resistance of the resist film containing it by increasing the melting point of the acid proliferator, and from the resist surface during the heat treatment by reducing the vapor pressure of the acid proliferator. For example, suppression of evaporation. Various kinds of such aliphatic rings can be used. From the viewpoint of availability, ease of synthesis, safety, and chemical stability, cyclohexane, menthane, adamantane, camphane (bornane), norbornane. , Pinane, tricyclodecane, tetracyclododecane and cyclopentadiene polymers are particularly preferred. Examples of these alicyclic rings and condensed alicyclic rings are shown in the following (5-10) to (5-18).

  In the above general formula, n represents an integer of 1 or more. In these aliphatic rings, some or all of the hydrogen atoms are substituted with halogen atoms, nitro groups, hydroxyl groups, methyl, ethyl, normal propyl, isopropyl, normal butyl, isobutyl, tertiary butyl, pentyl, isopentyl, etc. Alternatively, it may be replaced with an unsubstituted chain alkyl group. In addition, some carbon atoms contained in such organic groups may be replaced with nitrogen atoms, oxygen atoms, sulfur atoms, and the like.

By having such an aliphatic ring in the structure, the molecular weight of the acid proliferating agent is increased, which may cause problems such as a decrease in the amount per unit mass of the acid generated by the decomposition. In the compound represented by the general formula (5), A ¹ or A ² and A ³ are bonded to each other to form an aliphatic ring, whereby the aliphatic group as described above without increasing the molecular weight of the acid proliferating agent. This is preferable because the advantage of the ring can be obtained. Examples of such compounds are shown in the following general formula (5-19), but are not limited thereto.

Here structure as R represented by J, for example the general formula (5-1) to (5-9) shown in (JSO ₃ H) sulfonic acid compound represented by the like.

  In this embodiment, (B) compound can be used individually or in mixture of 2 or more types. The amount of the (B) compound used is preferably 0.5 to 10 parts by mass, and 0.5 to 5 parts by mass with respect to 100 parts by mass of the polymer (A) from the viewpoint of reducing line edge roughness as a resist. Is more preferable. In this case, if the amount of the compound (B) used is less than 0.5 parts by mass, the reduction of the line edge roughness may be insufficient. If it exceeds 10 parts by mass, an appropriate pattern profile is generated due to generation of excess acid. May not be formed.

((C) acid generator)
Examples of the acid generator (C) constituting the radiation-sensitive resin composition of the present embodiment include onium salts such as sulfonium salts and iodonium salts, organic halogen compounds, and sulfone compounds such as disulfones and diazomethane sulfones. it can.

  Specific preferred examples of the (C) acid generator include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] Triphenylsulfonium salt compounds such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate and triphenylsulfonium camphorsulfonate;

  4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2. 2.1] 4-cyclohexylphenyldiphenylsulfonium salt compounds such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate and 4-cyclohexylphenyldiphenylsulfonium camphorsulfonate;

  4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2- 4-cyclohexylphenyldiphenylsulfonium salt compounds such as bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium camphorsulfonate;

  Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2, Diphenyliodonium salt compounds such as 2-tetrafluoroethanesulfonate and diphenyliodonium camphorsulfonate;

  Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, Bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium camphor Bis (4-tert-butylphenyl) iodonium salt compounds such as sulfonate;

  1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (4-n-Butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2-bicyclo [2.2. 1] 1- (4-n-) such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium camphorsulfonate Butoxynaphthalen-1-yl) tetrahydrothiophenium salt compound;

  1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (6-n-Butoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium 2-bicyclo [2.2. 1] 1- (6-n-) such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium camphorsulfonate Butoxynaphthalen-2-yl) tetrahydrothiophenium salt compound;

  1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (3,5-Dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2. 1] 1- (3,5- such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium camphorsulfonate Dimethyl-4-hydroxyphenyl) tetrahydrothiol Salt compound;

N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept -5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- ( 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxy imide, N- (2- (3- tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecanyl) -1,1-difluoroethane-sulfonyloxy) bicyclo [2.2.1] hept -5 -D Bicyclo [2.2.1] hept-5 such as -2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide -An ene-2,3- dicarboximide compound etc. can be mentioned.

  In this embodiment, (C) an acid generator can be used individually or in mixture of 2 or more types. (C) From the viewpoint of ensuring the sensitivity and developability as a resist, the amount of the acid generator used is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer (A). 20 parts by mass is more preferable. In this case, when the amount of the acid generator used is less than 0.1 parts by mass, the sensitivity and developability tend to decrease. On the other hand, when the amount exceeds 30 parts by mass, the transparency to radiation decreases and a rectangular resist pattern. Tends to be difficult to obtain.

(Other additives)
In the radiation-sensitive resin composition of the present embodiment, an acid diffusion controller, an alicyclic additive having an acid dissociable group, an alicyclic additive not having an acid dissociable group, and a surface activity are included as necessary. Various additives such as sensitizers and sensitizers can be blended.

  The acid diffusion controlling agent controls the diffusion phenomenon in the resist film of the acid generated from the (C) acid generator and the acid generated from the (B) compound by irradiation, and suppresses an undesirable chemical reaction in the non-irradiated region. It is a component having By blending such an acid diffusion control agent, the storage stability of the resulting radiation-sensitive resin composition is improved, the resolution as a resist is further improved, and the holding time from irradiation to development processing ( The change in the line width of the resist pattern due to the variation in PED) can be suppressed, and a composition having excellent process stability can be obtained. The acid diffusion controller is preferably a nitrogen-containing organic compound whose basicity does not change by irradiation or heat treatment during the resist pattern formation step.

  Examples of such nitrogen-containing organic compounds include “tertiary amine compounds”, “amide group-containing compounds”, “quaternary ammonium hydroxide compounds”, “nitrogen-containing heterocyclic compounds”, and the like.

  Examples of the “tertiary amine compound” include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n. -Tri (cyclo) alkylamines such as octylamine, cyclohexyldimethylamine, tricyclohexylamine; alkanolamines such as triethanolamine, diethanolaniline; N, N, N ', N'-tetramethylethylenediamine, N, N , N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzenetetramethylenediamine, 2,2-bis (4-amino) Phenyl) propane, 2- (3-aminophenyl) -2- (4) Aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1 -(4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, bis (2-dimethylaminoethyl) ether, bis (2 -Diethylaminoethyl) ether and the like.

  Examples of the “amide group-containing compound” include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, N- t-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, 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-butoxycarbonylhexamethyl Range amine, 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-1,12-diaminododecane, N, N '-Di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenz Imidazole, Nt-butoxycarbonyl-pyrrolidine, Nt-butoxycarbonyl-piperidine, Nt-buto In addition to Nt-butoxycarbonyl group-containing amino compounds such as cycarbonyl-4-hydroxy-piperidine, Nt-butoxycarbonyl-morpholine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N- Examples thereof include methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like.

  Examples of the “quaternary ammonium hydroxide compound” include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra-n-propylammonium hydroxide, tetra-n-butylammonium hydroxide, and the like.

  Examples of the “nitrogen-containing heterocyclic compound” include imidazoles such as imidazole, 4-methylimidazole, 1-benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole; In addition to piperazines such as piperazine and 1- (2-hydroxyethyl) piperazine, piperidines such as pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, tert-butyl-4-hydroxy-1-piperidinecarboxylate, Examples include 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane.

  Of the above nitrogen-containing heterocyclic compounds, tertiary amine compounds, amide group-containing compounds, and nitrogen-containing heterocyclic compounds are preferable, and among the amide group-containing compounds, Nt-butoxycarbonyl group-containing amino compounds are preferable, including Among the nitrogen heterocyclic compounds, imidazoles are preferable.

  The acid diffusion control agents can be used alone or in admixture of two or more. The blending amount of the acid diffusion controller is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less with respect to 100 parts by mass of the (A) polymer. In this case, if the compounding amount of the acid diffusion controller exceeds 15 parts by mass, the sensitivity as a resist and the developability of the radiation irradiated part may be lowered. If the amount of the acid diffusion controller is less than 0.001 part by mass, the pattern shape and dimensional fidelity as a resist may be lowered depending on the process conditions.

  In addition, an alicyclic additive having an acid dissociable group or an alicyclic additive having no acid dissociable group is a component that further improves dry etching resistance, pattern shape, adhesion to a substrate, and the like. It is.

  Examples of such alicyclic additives include 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α-butyrolactone ester, and 1,3-adamantane dicarboxylic acid. Di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantanediacetate di-t-butyl, 2,5-dimethyl-2,5-di (adamantyl) Adamantane derivatives such as carbonyloxy) hexane; deoxycholic acid t-butyl, deoxycholic acid t-butoxycarbonylmethyl, deoxycholic acid 2-ethoxyethyl, deoxycholic acid 2-cyclohexyloxyethyl, deoxycholic acid 3-oxocyclohexyl , Deoxyco Deoxycholic acid esters such as tetrahydropyranyl acid, deoxycholic acid mevalonolactone ester; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, 2-cyclohexyloxyethyl lithocholic acid, lithocol Lithocholic acid esters such as 3-oxocyclohexyl acid, tetrahydropyranyl lithocholic acid, mevalonolactone ester of lithocholic acid; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-butyl adipate, di-t-butyl adipate And alkyl carboxylic acid esters.

  These alicyclic additives can be used alone or in admixture of two or more. The compounding amount of the alicyclic additive is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, with respect to 100 parts by mass of the polymer (A). In this case, when the blending amount of the alicyclic additive exceeds 50 parts by mass, the heat resistance as a resist tends to decrease.

  Further, the surfactant as an additive is a component having an effect of improving coating property, 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. In addition to nonionic surfactants such as polyethylene glycol distearate, KP341 (manufactured 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), Fluorad FC430, FC431 (manufactured by Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( Asahi Glass Co., Ltd.).

  These surfactants can be used alone or in admixture of two or more. It is preferable that the compounding quantity of surfactant is 2 mass parts or less with respect to 100 mass parts of acid dissociable group containing polymers.

  Examples of the “sensitizer” include carbazoles, benzophenones, rose bengals, anthracenes, phenols and the like. These sensitizers can be used alone or in admixture of two or more. A sensitizer absorbs radiation energy and transmits the energy to the acid generator, thereby increasing the amount of acid produced, thereby improving the apparent sensitivity of the radiation-sensitive resin composition. Has the effect of The blending amount of the sensitizer is preferably 50 parts by mass or less with respect to 100 parts by mass of the polymer (A).

  Furthermore, examples of additives other than those mentioned above include antihalation agents, adhesion assistants, storage stabilizers, antifoaming agents, and the like.

((A) Polymer production method)
The method for producing the polymer (A) that constitutes the radiation-sensitive resin composition of the present embodiment is not particularly limited. For example, the polymerization failure corresponding to each repeating unit constituting the desired molecular composition is not limited. The saturated monomer can be produced by polymerizing in a suitable solvent in the presence of a radical polymerization initiator, a chain transfer agent or the like. The radical polymerization initiator is preferably added so as to have a sufficiently high concentration in order to realize a sufficient polymerization rate. However, if the ratio of the amount of radical polymerization initiator to the amount of chain transfer agent is too high, a radical-radical coupling reaction will occur and an undesirable non-living radical polymer will be formed, so the resulting polymer will have a molecular weight and molecular weight distribution, etc. In other words, a portion having uncontrolled characteristics in the polymer characteristics is included. The molar ratio between the amount of radical polymerization initiator and the amount of chain transfer agent is preferably (1: 1) to (0.005: 1).

  Although it does not specifically limit as said radical polymerization initiator, A thermal polymerization initiator, a redox polymerization initiator, and a photoinitiator are mentioned. Specific examples include polymerization initiators such as peroxides and azo compounds. More specific radical polymerization initiators include t-butyl hydroperoxide, t-butyl perbenzoate, benzoyl peroxide, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azo. Examples thereof include bisisobutyronitrile (AIBN), 1,1′-azobis (cyclohexanecarbonitrile), dimethyl-2,2′-azobisisobutyrate (MAIB), and the like.

  Examples of the chain transfer agent include pyrazole derivatives and alkylthiols.

  As for the polymerization operation, polymerization can be carried out by a usual method such as batch polymerization or dropping polymerization. For example, for the monomer corresponding to each of the above (1-1) repeating unit, (1-2) repeating unit and other repeating units, the necessary type and amount are dissolved in an organic solvent, and a radical polymerization initiator and By polymerizing in the presence of a chain transfer agent, a polymer (A) is obtained. As the polymerization solvent, an organic solvent capable of dissolving the monomer, radical polymerization initiator and chain transfer agent is generally used. Examples of the organic solvent include ketone solvents, ether solvents, aprotic polar solvents, ester solvents, aromatic solvents, and linear or cyclic aliphatic solvents. Examples of the ketone solvent include methyl ethyl ketone and acetone. Examples of ether solvents include alkoxyalkyl ethers such as methoxymethyl ether, ethyl ether, tetrahydrofuran, and 1,4-dioxane. Examples of the aprotic polar solvent include dimethylformamide and dimethylsulfoxide. Examples of ester solvents include alkyl acetates such as ethyl acetate and methyl acetate. Aromatic solvents include alkylaryl solvents such as toluene, xylene, and halogenated aromatic solvents such as chlorobenzene. Examples of the aliphatic solvent include hexane and cyclohexane.

  The polymerization temperature is generally 20 to 120 ° C, preferably 50 to 110 ° C, more preferably 60 to 100 ° C. Although polymerization may be performed even in a normal air atmosphere, polymerization in an inert gas atmosphere such as nitrogen or argon is preferable. (A) The molecular weight of the polymer can be adjusted by controlling the ratio between the monomer amount and the chain transfer agent amount. The polymerization time is generally 0.5 to 144 hours, preferably 1 to 72 hours, more preferably 2 to 24 hours.

  (A) The polymer may have a residue derived from a chain transfer agent at the end of the molecular chain, may not have a residue derived from the chain transfer agent at the end of the molecular chain, It may be in a state in which a part of the residue derived from the chain transfer agent remains.

  The polymer (A) is naturally low in impurities such as halogen and metal, but the residual monomer or oligomer component is preferably not more than a predetermined value, for example, 0.1% by mass or less by HPLC analysis. Thereby, not only can the sensitivity, resolution, process stability, pattern shape and the like as a resist be further improved, but also a radiation-sensitive resin composition that can be used as a resist with little change over time such as foreign matter in liquid and sensitivity.

  (A) As a purification method of a polymer, the following method is mentioned, for example. As a method for removing impurities such as metals, (A) a polymer solution is adsorbed using a zeta potential filter, or (A) the polymer solution is washed with an acidic aqueous solution such as oxalic acid or sulfonic acid. And a method of removing the metal in a chelated state. In addition, as a method of removing residual monomer and oligomer components below the specified value, liquid-liquid extraction method that removes residual monomer and oligomer components by combining water washing and an appropriate solvent, those with a specific molecular weight or less A purification method in a solution state such as ultrafiltration to extract and remove only (A) a residual monomer by coagulating the polymer in the poor solvent by dripping the polymer solution into the poor solvent (A) There are a reprecipitation method for removing etc. and a purification method in a solid state such as washing the filtered polymer slurry with a poor solvent. Moreover, these methods can also be combined. The poor solvent used in the reprecipitation method depends on the physical properties of the polymer to be purified (A) and cannot be generally exemplified. However, those skilled in the art will appropriately select the poor solvent according to the physical properties of the polymer. can do.

  (A) The weight average molecular weight in terms of polystyrene (hereinafter abbreviated as “Mw”) by gel permeation chromatography (GPC) of the polymer is usually 1,000 to 300,000, preferably 2,000 to 300,000. More preferably, it is 2,000-12,000. (A) When the Mw of the polymer is less than 1,000, the heat resistance as a resist tends to be lowered, and when it exceeds 300,000, the developability as a resist tends to be lowered.

  The ratio (Mw / Mn) of (A) Mw of the polymer to polystyrene-reduced number average molecular weight (hereinafter abbreviated as “Mn”) by gel permeation chromatography (GPC) is preferably 1-5, Preferably it is 1-3, Most preferably, it is 1-1.6.

  The radiation-sensitive resin composition of the present embodiment is usually dissolved in a solvent such that the total solid content concentration is 3 to 50% by mass, preferably 5 to 25% by mass. It is filtered through a filter of about 2 μm and prepared as a radiation sensitive resin composition solution. Examples of the solvent used in the preparation of the radiation sensitive resin composition solution include linear or branched ketones such as 2-pentanone, 2-hexanone, 2-heptanone, and 2-octanone; cyclopentanone Cyclic ketones such as cyclohexanone; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; 2-hydroxypropions such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate Alkyl alkyls; 3-alkoxypropionate alkyls such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, etc., ethylene Recall monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, n-butyl acetate, methyl pyruvate, Examples include ethyl pyruvate, N-methylpyrrolidone, and γ-butyrolactone.

  These solvents may be used alone or in admixture of two or more, but propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclohexanone, γ-butyrolactone, ethyl 2-hydroxypropionate, 3-ethoxy It is preferable to contain at least one selected from ethyl propionate. However, cyclohexanone is an effective solvent from the viewpoint of solubility, but its use is preferably avoided as much as possible because of its toxicity.

  When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition solution prepared as described above is coated with, for example, a silicon wafer or aluminum by an appropriate application means such as spin coating. A resist film is formed by coating on a substrate such as a wafer, and after pre-baking (hereinafter referred to as PB) in some cases, the resist film is exposed to form a predetermined resist pattern. An ArF excimer laser (wavelength 193 nm) is used as the radiation used at that time. The exposure conditions such as the exposure amount are appropriately selected according to the composition of the composition. In the present invention, in order to improve the apparent sensitivity of the resist film, it is preferable to perform a heat treatment (hereinafter referred to as PEB) after exposure. The heating conditions vary depending on the composition of the composition and the like, but are usually 30 to 200 ° C, preferably 40 to 150 ° C. Further, when forming a resist pattern, a protective film can be provided on the resist film in order to prevent the influence of basic impurities contained in the environmental atmosphere. Next, the exposed resist film is developed with an alkali developer to form a predetermined resist pattern. Examples of the alkali developer include alkali metal hydroxides; aqueous ammonia; mono-, di- or tri-alkanolamines; heterocyclic amines; tetramethylammonium hydride; choline; 1,8-diazabicyclo- At least one alkaline compound such as [5,4,0] -7-undecene, 1,5-diazabicyclo- [4,3,0] -5-nonene is usually 1 to 10% by mass, preferably 2 An alkaline aqueous solution dissolved to a concentration of ˜5% by mass is used. In addition, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol, or a surfactant can be added to the developer composed of the alkaline aqueous solution. In addition, when using the developing solution which consists of alkaline aqueous solution in this way, generally it wash | cleans with water after image development.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not restrict | limited at all by these Examples. Here, the part is based on mass unless otherwise specified.

  Each measurement and evaluation in Examples and Comparative Examples was performed as follows.

(Mw)
Using a GPC column (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation, monodisperse polystyrene was used as the standard under the analysis conditions of a flow rate of 1.0 ml / min, elution solvent tetrahydrofuran, and column temperature of 40 ° C. Measured by gel permeation chromatography (GPC).

(sensitivity)
Using a silicon wafer (ARC29) having an ARC29 (Brewer Science) film with a film thickness of 780 Å formed on the wafer surface, each composition solution was applied onto the substrate by spin coating, and then on a hot plate. Then, a resist film having a thickness of 0.20 μm formed by performing PB under the conditions shown in Table 2 was exposed through a mask pattern using a Nikon ArF excimer laser exposure apparatus (numerical aperture 0.75). Then, after carrying out PEB under the conditions shown in Table 2, the film was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 25 ° C. under the conditions shown in Table 2, washed with water and dried. A resist pattern was formed. At this time, an exposure amount for forming a line-and-space pattern (1L1S) having a line width of 0.090 μm in a one-to-one line width was defined as an optimum exposure amount, and this optimum exposure amount was defined as sensitivity.

(resolution)
The minimum resist pattern dimension that can be resolved at the optimum exposure dose is defined as the resolution.

(Pattern shape)
The lower side dimension Lb and the upper side dimension La of the rectangular cross section of the line-and-space pattern (1L1S) having a line width of 0.090 μm were measured with a scanning electron microscope, and 0.85 ≦ La / Lb ≦ 1 was satisfied, In addition, when the pattern shape has no bottom, the pattern shape is “good”, and when 0.85> La / Lb, the pattern shape is “bad”.

(Line edge roughness (LER))
When observing a 90 nm (1L / 1S) pattern resolved at the optimum exposure dose, the line width is observed at an arbitrary point when observing from the upper part of the pattern with Hitachi SEM: S9220. Is expressed as 3 sigma, a value of 10 nm or more is expressed as poor and a value of less than 10 nm is expressed as good.

(Synthesis Example 1)
Compound (S1-1) 48.59 g (50 mol%), compound (S1-2) 20.67 g (20 mol%) and compound (S1-3) 30.74 g (30 mol%) were dissolved in 2-butanone 200 g, Furthermore, a monomer solution charged with 4.03 g of dimethyl 2,2′-azobis (2-methylpropionate) is prepared, and a 1000 mL three-necked flask charged with 100 g of 2-butanone is 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 dropwise at a rate of 10 mL / 5 min using a dropping funnel. 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 is cooled to 30 ° C. or less by water cooling, charged into 2000 g of methanol, and the precipitated white powder is separated by furnace. The white powder separated in the furnace was washed twice in 400 g of methanol and washed, and then separated in the furnace and dried at 50 ° C. for 17 hours to obtain a white powder resin (74 g, yield 74%). . This resin has a molecular weight of 9800, and the content ratio of each of the repeating units represented by the compound (S1-1), the compound (S1-2) and the compound (S1-3) is (S1-1) :( S1-2): (S1-3) = 33.2: 15.8: 51.0 (mol ratio). This resin is referred to as “resin (A-1)”.

(Synthesis Example 2)
Compound (S2-1) 10.70 g (13 mol%), compound (S2-2) 39.14 g (37 mol%) and compound (S2-3) 50.16 g (50 mol%) were dissolved in 2-butanone 200 g, Further, a monomer solution charged with 1.52 g of 2,2′-azobisisobutyronitrile is prepared, and a 1000 mL three-necked flask charged with 100 g of 2-butanone is 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 dropwise at a rate of 10 mL / 5 min using a dropping funnel. 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 is cooled to 30 ° C. or less by water cooling, charged into 2000 g of methanol, and the precipitated white powder is separated by furnace. The white powder separated in the furnace was washed twice with 400 g of methanol as a slurry and then separated in the furnace and dried at 50 ° C. for 17 hours to obtain a white powder resin (78 g, yield 78%). . This resin has a molecular weight of 8700, and the content ratio of each of the repeating units represented by the compound (S2-1), the compound (S2-2) and the compound (S2-3) is (S2-1) :( S2-2): (S2-3) = 14.7: 34.2: 51.1 (mol ratio). This resin is referred to as “resin (A-2)”.

(Synthesis Example 3)
35.38 g (40 mol%) of the compound (S3-1), 10.69 g (10 mol%) of the compound (S3-2) and 53.93 g (50 mol%) of the compound (S3-3) were dissolved in 200 g of 2-butanone, Furthermore, a monomer solution charged with 5.59 g of dimethyl 2,2′-azobis (2-methylpropionate) is prepared, and a 1000 mL three-necked flask charged with 100 g of 2-butanone is 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 dropwise at a rate of 10 mL / 5 min using a dropping funnel. 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 is cooled to 30 ° C. or less by water cooling, charged into 2000 g of methanol, and the precipitated white powder is separated by furnace. The white powder separated in the furnace was washed twice in 400 g of methanol and washed, and then separated in the furnace and dried at 50 ° C. for 17 hours to obtain a white powder resin (81 g, yield 81%). . This resin has a molecular weight of 6600, and the content ratio of each of the repeating units represented by the compound (S3-1), the compound (S3-2) and the compound (S3-3) is (S3-1) :( It was a copolymer of (S3-2) :( S3-3) = 39.8: 7.7: 52.5 (mol ratio). This resin is referred to as “resin (A-3)”.

  Radiation sensitive resin composition solutions were prepared as shown in Examples 1 to 6 and Comparative Example 1 below. Components other than the resins (A-1) to (A-3) are as follows. The composition of each radiation sensitive resin composition solution is shown in Table 1.

(Compound (B))
(B-1): Pinanediol-camphorsulfonic acid ester (see the following formula (B-1))
(B-2): Pinanediol-trifluoromethanesulfonic acid ester (see the following formula (B-2))

(Acid generator (C))
(C-1): Triphenylsulfonium nonafluoro-n-butanesulfonate (C-2): 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate

(Acid diffusion control agent (D))
(D-1): tert-butyl-4-hydroxy-1-piperidinecarboxylate

(Solvent (E))
(E-1): Propylene glycol monomethyl ether acetate

Example 1
Resin (A-1) 100 parts, Compound (B-1) 2 parts, Acid generator (C-1) 2 parts, Acid generator (C-2) 2.5 parts, Acid diffusion controller (D-1 ) 0.55 parts and 900 parts of solvent (E-1) were mixed to obtain a radiation sensitive resin composition.

(Example 2)
A radiation sensitive resin composition was obtained in the same manner as in Example 1 except that (B-2) was used in place of the compound (B-1).

(Example 3)
A radiation-sensitive resin composition was obtained in the same manner as in Example 1 except that the resin (A-1) was changed to the resin (A-2).

Example 4
A radiation-sensitive resin composition was obtained in the same manner as in Example 3 except that (B-2) was used instead of the compound (B-1).

(Example 5)
A radiation-sensitive resin composition was obtained in the same manner as in Example 1 except that the resin (A-1) was changed to the resin (A-3).

(Example 6)
A radiation sensitive resin composition was obtained in the same manner as in Example 5 except that (B-2) was used in place of the compound (B-1).

(Comparative Example 1)
A radiation sensitive resin composition was obtained in the same manner as in Example 1 except that the compound (B-1) was not used.

  Various evaluation was performed about each obtained radiation sensitive resin composition solution. The evaluation results are shown in Table 3.

  From Table 3, the radiation sensitive resin compositions of Examples 1 to 6 were excellent in line edge roughness (LER), pattern shape, resolution and sensitivity. On the other hand, since the radiation sensitive resin composition of the comparative example 1 does not have a compound (B), it was especially inferior to LER and pattern shape.

  The radiation-sensitive resin composition of the present invention is a microfabrication that uses various kinds of radiation such as deep ultraviolet rays typified by KrF excimer laser or ArF excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams. It can be suitably used as a chemically amplified resist useful in the present invention, and can be used very suitably in the production of semiconductor devices that are expected to be further miniaturized in the future.

Claims (3)

(A) an acid dissociable group-containing polymer having a repeating unit represented by the following general formula (1-1) and a repeating unit represented by the following general formula (1-2); and (B) the following general formula (1- A radiation-sensitive resin composition comprising the compound represented by 3) and (C) an acid generator that generates an acid upon irradiation with radiation.

[In the general formula (1-1), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and Z represents a protective group that can be removed by the action of an acid. In General Formula (1-2), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² is independently a hydrogen atom, a linear or branched group having 1 to 4 carbon atoms. An alkyl group, a linear or branched alkoxy group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms is represented. m is an integer of 0-3. In General Formula (1-3), R ³ and R ⁴ each independently represent a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a perfluoroalkyl group. n represents an integer of 1 to 8, A represents an acid dissociable group, and G represents a fluorine atom or a monovalent organic group. ] The radiation sensitive resin composition according to claim 1, wherein the (A) acid dissociable group-containing polymer further has a repeating unit represented by the following general formula (1-4).

[In General Formula (1-4), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and X represents a substituted or unsubstituted polycyclic alicyclic hydrocarbon group having 4 to 20 carbon atoms. . ] The radiation sensitive resin composition according to claim 1 or 2, wherein in the general formula (1-3), R ³ and R ⁴ are fluorine atoms.