JP5347465B2 - Radiation sensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition which is adaptable to the formation of a fine resist pattern using a light source of a short wavelength up to 90 nm, excels in resolution, ensures small LWR and good PEB temperature dependency, excels in pattern collapse resistance and hardness to cause defect, and is suitably used even in an immersion exposure step. <P>SOLUTION: The radiation-sensitive resin composition includes a resin (A) including a repeating unit (a-1) having adamantyl lactone in a side chain and a repeating unit (a-2) having an acid dissociable group and a radiation-sensitive acid generator (B) including a sulfonium salt of a specific structure. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a radiation-sensitive resin composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photolithography processes. More specifically, it can cope with the formation of a fine resist pattern using an exposure light source such as far-ultraviolet light having a wavelength of 220 nm or less and not only has excellent resolution performance, but also has a line width roughness (hereinafter referred to as “line width roughness”). , Sometimes referred to as “LWR”), post-exposure bake (hereinafter sometimes referred to as “PEB”) temperature dependence, excellent pattern collapse characteristics and defect performance, and further commercialization The present invention also relates to a radiation-sensitive resin composition that can be suitably used in a liquid immersion exposure process.

  The radiation sensitive resin composition generates an acid in the exposed area by irradiating radiation such as far ultraviolet rays typified by a KrF excimer laser or an ArF excimer laser, and a reaction using the generated acid as a catalyst. And a composition for changing the dissolution rate of the unexposed portion in the developer to form a resist pattern on the substrate. When a KrF excimer laser is used as a light source, by using a radiation-sensitive resin composition mainly composed of a resin having a basic skeleton of poly (hydroxystyrene) having a low absorbance in the 248 nm region, high sensitivity and high It is feasible to form a resist pattern with high resolution.

  In order to form a further fine resist pattern, it is preferable to expose by irradiating with radiation having a shorter wavelength. However, when an ArF excimer laser or the like that generates radiation having a shorter wavelength is used as a light source, there is a problem that a compound such as poly (hydroxystyrene) cannot be suitably used. This is because a compound having an aromatic ring essentially has a large absorbance in the 193 nm region. For this reason, when using an ArF excimer laser as a light source, a radiation-sensitive resin composition containing a resin containing an alicyclic hydrocarbon skeleton, which does not have a large absorbance in the 193 nm region, is used. Moreover, it is disclosed that the resist performance of the radiation-sensitive resin composition is dramatically improved by including a repeating unit having various lactone skeletons in a resin containing an alicyclic hydrocarbon skeleton.

  As such a lactone skeleton, for example, a radiation sensitive resin composition using a mevalonic lactone skeleton or a γ-butyrolactone skeleton is disclosed (for example, see Patent Documents 1 and 2). Moreover, the radiation sensitive resin composition using an alicyclic lactone skeleton is disclosed (for example, refer patent documents 3-14).

  However, in order to cope with further miniaturization with a line width of 90 nm or less, the present resist is not suitable for the radiation-sensitive resin composition simply improved in resolution performance as shown in the above-mentioned patent document. It has become difficult to satisfy various required performances in In the future, as further miniaturization progresses, it is suitably used not only in resolution performance but also in immersion exposure processes that are currently in practical use. For example, low LWR, low defect, low PEB There is a need to develop materials that satisfy various required performance such as temperature dependency and resistance to pattern collapse.

Note that defectivity indicates the ease with which defects are generated in a photolithography process. Examples of the defect in the photolithography process include a watermark defect, a blob defect, a bubble defect, and the like. If a large number of these defects occur in device manufacturing, the device yield will be greatly affected.
The watermark defect is a defect in which a droplet trace of the immersion liquid remains on the resist pattern, and the blob defect is a resin once dissolved in the developer deposited by a rinse shock, and the substrate It is a defect reattached to the surface. Further, the bubble defect is a defect in which a desired pattern cannot be obtained due to a change in optical path due to the bubble of the immersion liquid during immersion exposure.

JP-A-9-73173 US Pat. No. 6,388,101 JP 2000-159758 A JP 2001-109154 A JP 2004-101642 A JP 2003-113174 A Japanese Patent Laid-Open No. 2003-147023 JP 2002-308866 A JP 2002-371114 A JP 2003-64134 A JP 2003-270787 A JP 2000-26446 A JP 2000-122294 A Japanese Patent No. 3952946

  The present invention has been made to cope with such a problem, and is particularly used in a photolithography process using an ArF excimer laser as a light source, and uses a short wavelength light source capable of a line width of 90 nm or less. In addition to excellent resolution performance, it has a low LWR, good PEB temperature dependency, excellent pattern collapse resistance and defect performance, and is currently being put into practical use. Another object of the present invention is to provide a radiation-sensitive resin composition useful as a chemically amplified resist that can be suitably used in the immersion exposure process.

As a result of intensive studies, the present inventors have found that the above-described problems can be achieved by using a predetermined resin and a radiation-sensitive acid generator, and have completed the present invention. That is, the radiation sensitive resin composition of the present invention includes a resin (A) containing a repeating unit (a-1) represented by the following formula (1) and a repeating unit (a-2) having an acid dissociable group: ,
It is selected from the radiation sensitive acid generator (b-1) containing the compound represented by the following formula (2) and the radiation sensitive acid generator (b-2) containing the compound represented by the formula (2 ′). It contains at least one radiation sensitive acid generator (B).

式（１）において、Ｒ¹は水素原子またはメチル基を表し、Ｒ²は炭素数１〜１２のアルキレン基または脂環式アルキレン基を表し、ｍは１〜３の整数を表し、
式（２）において、Ｒ³はフッ素原子、水酸基、炭素数１〜１０の直鎖状もしくは分岐状のアルキル基、炭素数１〜１０の直鎖状もしくは分岐状のアルコキシル基、または、炭素数２〜１１の直鎖状もしくは分岐状のアルコキシカルボニル基を表し、
式（２’）において、Ｒ^3'は水素原子、フッ素原子、水酸基、炭素数１〜１０の直鎖状もしくは分岐状のアルキル基、炭素数１〜１０の直鎖状もしくは分岐状のアルコキシル基、または、炭素数２〜１１の直鎖状もしくは分岐状のアルコキシカルボニル基を表し、
式（２）および式（２’）において、Ｒ⁴は炭素数１〜１０の直鎖状もしくは分岐状のアルキル基、炭素数１〜１０の直鎖状もしくは分岐状のアルコキシル基、または、炭素数２〜１１の直鎖状、分岐状もしくは環状のアルカンスルホニル基を表し、Ｒ⁵は相互に独立に炭素数１〜１０の直鎖状もしくは分岐状のアルキル基、置換されていてもよいフェニル基もしくはナフチル基、または、２個のＲ⁵が互いに結合して炭素数２〜１０の２価の基を形成しており、該２価の基は置換されていてもよく、ｋは０〜２の整数であり、ｒは０〜１０の整数であり、
Ｘ^-は下記式（３）〜式（６）のいずれか１つのアニオンであり、Ｘ^-が下記式（３）で表されるアニオンの場合、式（２）および式（２’）における２個のＲ⁵は互いに結合して炭素数２〜１０の２価の基を形成することはない。

In Formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkylene group having 1 to 12 carbon atoms or an alicyclic alkylene group, m represents an integer of 1 to 3,
In Formula (2), R ³ is a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or a carbon number 2 to 11 linear or branched alkoxycarbonyl groups,
In the formula (2 ′), R ^{3 ′} is a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a linear or branched alkoxyl group having 1 to 10 carbon atoms. Or a linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms,
In Formula (2) and Formula (2 ′), R ⁴ is a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or carbon Represents a linear, branched or cyclic alkanesulfonyl group having 2 to 11 carbon atoms, and R ⁵ is independently a linear or branched alkyl group having 1 to 10 carbon atoms and optionally substituted phenyl. Group or naphthyl group, or two R ⁵ 's bonded to each other to form a divalent group having 2 to 10 carbon atoms, the divalent group may be substituted, and k is 0 to Is an integer of 2, r is an integer of 0 to 10,
X ⁻ is any one of the following formulas (3) to (6), and when X ⁻ is an anion represented by the following formula (3), 2 in formula (2) and formula (2 ′) The R ⁵ groups are not bonded to each other to form a divalent group having 2 to 10 carbon atoms.

式（３）において、式（２）のアニオンとなる場合、Ｒ⁶は水素原子、フッ素原子、または炭素数１〜１２の置換されていてもよい炭化水素基を表し、ｎは１〜１０の整数であり、式（２’）のアニオンとなる場合、Ｒ⁶は水素原子、または炭素数１〜１２の置換されていてもよい炭化水素基を表し、ｎは１〜１０の整数であり、
式（４）において、Ｒ⁷は炭素数１〜６のアルキルカルボニル基、アルキルカルボニルオキシ基もしくはヒドロキシアルキル基で置換されるか、または無置換の炭素数１〜１２の炭化水素基を表し、
式（５）および式（６）において、Ｒ⁸は相互に独立に、炭素数１〜１０の直鎖状もしくは分岐状のフッ素原子を含有するアルキル基、または２個のＲ⁸が結合して形成される炭素数２〜１０のフッ素原子を含有する置換されていてもよい２価の基を表す。

In Formula (3), when it becomes an anion of Formula (2), R ⁶ represents a hydrogen atom, a fluorine atom, or a hydrocarbon group having 1 to 12 carbon atoms, and n is 1 to 10 When it is an integer and becomes an anion of the formula (2 ′), R ⁶ represents a hydrogen atom or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, n is an integer of 1 to 10,
In the formula (4), R ⁷ is substituted with an alkylcarbonyl group having 1 to 6 carbon atoms, an alkylcarbonyloxy group or a hydroxyalkyl group, or represents an unsubstituted hydrocarbon group having 1 to 12 carbon atoms,
In Formula (5) and Formula (6), R ⁸ is independently of each other an alkyl group containing a linear or branched fluorine atom having 1 to 10 carbon atoms, or two R ⁸ are bonded. The divalent group which may be substituted containing the C2-C10 fluorine atom formed is represented.

In the above formula (1), represented by R ^2, an alkylene group or an alicyclic alkylene group having 1 to 12 carbon atoms, a straight-chain alkylene group having 1 to 12 carbon atoms, having 2 to 12 carbon atoms It is a branched alkylene group or a cycloalkylene group.

  Since the radiation-sensitive resin composition of the present invention contains a resin having a specific chemical structure as a repeating unit and a specific radiation-sensitive acid generator, it is particularly used in a photolithography process using an ArF excimer laser as a light source. It can cope with the formation of a fine resist pattern using a short wavelength enabling a line width of 90 nm or less, not only has excellent resolution performance, but also has a low LWR and good PEB temperature dependency, It is excellent in pattern collapse characteristics and defect performance, and can also be suitably used in an immersion exposure process that is currently in practical use.

The radiation-sensitive resin composition of the present invention is not limited to the following embodiments, and is based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. However, it should be understood that modifications, improvements, and the like as appropriate belong to the scope of the present invention.
The radiation-sensitive resin composition of the present invention includes a resin (A) containing a repeating unit (a-1) represented by the above formula (1) and a repeating unit (a-2) having an acid dissociable group, A radiation-sensitive acid generator (B) containing a compound represented by the formula (2). The radiation sensitive resin composition of this invention becomes alkali-soluble by the effect | action of an acid by containing resin (A).
Further, a nitrogen-containing compound (hereinafter also referred to as “nitrogen-containing compound (C)”), various additives (hereinafter also referred to as “additive (D)”), a solvent (hereinafter also referred to as “solvent (E)”). Etc. may be further contained. Hereinafter, each component will be described.

Resin (A):
It is preferable that resin (A) has few low molecular weight components. The content of the low molecular weight component is preferably 0.1% by mass or less, more preferably 0.07% by mass or less, based on 100% by mass of the resin (A) in terms of solid content. It is particularly preferable that the content be 05% by mass or less. When the content of the low molecular weight component is 0.1% by mass or less, the resin (A) is used to form a photoresist film, and when immersion exposure is performed, the water contacts the photoresist film. It is possible to reduce the amount of eluate. In addition, foreign matters are not generated in the resist during storage, and non-uniform coating does not occur during resist application, and the occurrence of defects during formation of the resist pattern can be sufficiently suppressed. Here, the “low molecular weight component” is a monomer, dimer, trimer or oligomer compound of a monomer constituting a repeating unit, and a weight average molecular weight (hereinafter, referred to as polystyrene) by gel permeation chromatography (GPC). “Mw”) refers to a component having 500 or less.

  The low molecular weight component can be removed by, for example, chemical purification methods such as washing with water and liquid-liquid extraction, or a combination of these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. The low molecular weight component can be analyzed by high performance liquid chromatography (HPLC) of the resin (A). In addition, since resin (A) can further improve the sensitivity, resolution, process stability, pattern shape, and the like when it is used as a resist, it is preferable that the amount of impurities such as halogen and metal is small.

Although Mw of resin (A) is not specifically limited, It is preferable that it is 1000-100000, It is more preferable that it is 1000-30000, It is especially preferable that it is 1000-20000. If the Mw of the resin (A) is less than 1000, the heat resistance when used as a resist may decrease. On the other hand, if the Mw of the resin (A) is more than 100,000, the developability when used as a resist may be lowered. The ratio (Mw / Mn) of Mw of the resin (A) to the number average molecular weight (hereinafter referred to as “Mn”) in terms of polystyrene by gel permeation chromatography (GPC) is usually 1.0 to 5. 0, preferably 1.0 to 3.0, and more preferably 1.0 to 2.0.
Moreover, the radiation sensitive resin composition of this invention may contain 1 type of resin (A) individually, and may contain 2 or more types of resin (A).

The resin (A) has a repeating unit (a-1) represented by the above formula (1). The resin (A) may contain one type of repeating unit (a-1) or may contain two or more types of repeating units (a-1).
The alkylene group having 1 to 12 carbon atoms represented by R ² in Formula (1) is preferably a linear alkylene group or a branched alkylene group, such as a methylene group, an ethylene group, a propylene group, or isopropylene. Group, n-butylene group, isobutylene group and the like.
Among these, a methylene group, an ethylene group, a propylene group, and an isopropylene group are preferable.
The alicyclic alkylene group may be either monocyclic or bridged cyclic, such as 1,4-cyclohexylene group, 1,3-cyclohexylene group, 1,2-cyclohexylene group, 2,3-bicyclo [2.2.1] heptylene group, 2.5-bicyclo [2.2.1] heptylene group, 2,6-bicyclo [2.2.1] heptylene group, 1,3-adaman Examples include a tylene group.
Of these, cycloalkylene groups such as 1,4-cyclohexylene group, 1,3-cyclohexylene group and 1,2-cyclohexylene group are preferable.

上記（１−１）〜（１−５）で表される単量体は、単独でも混合物でも使用できる。 Preferable monomers that give the repeating unit (a-1) include monomers represented by the following formulas (1-1) to (1-5). In the following formulas (1-1) to (1-5), R ¹ represents a hydrogen atom or a methyl group independently of each other as in the above formula (1).

The monomers represented by the above (1-1) to (1-5) can be used singly or as a mixture.

Resin (A) contains the repeating unit (a-2) which has an acid dissociable group. The repeating unit (a-2) may be used alone or in combination of two or more.
Examples of the acid dissociable group include a —C (R ⁹ ) ₃ group and a t-butoxycarbonyl group of a repeating unit represented by the following formula (7).

上記式（７）において、Ｒ’は水素原子、メチル基またはトリフルオロメチル基を表す。また、Ｒ⁹は、相互に独立に炭素数４〜２０の１価の脂環式炭化水素基もしくはその誘導体または１〜４の直鎖状もしくは分岐状のアルキル基を表し、かつＲ⁹の少なくとも１つが該脂環式炭化水素基もしくはその誘導体であるか、あるいは何れか２つのＲ⁹が相互に結合して、それぞれが結合している炭素原子とともに炭素数４〜２０の２価の脂環式炭化水素基もしくはその誘導体を形成し、残りのＲ⁹が炭素数１〜４の直鎖状もしくは分岐状のアルキル基または炭素数４〜２０の１価の脂環式炭化水素基もしくはその誘導体を表す。
上記式（７）中のＲ⁹において、炭素数４〜２０の１価または２価の脂環式炭化水素基としては、例えば、シクロブタン、シクロペンタン、シクロヘキサン、シクロヘプタン、シクロオクタン等のシクロアルカン類、ノルボルナン、トリシクロデカン、テトラシクロドデカン、アダマンタン等の脂環族環からなる基；これらの脂環族環からなる基を、メチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基、ｎ−ブチル基、２−メチルプロピル基、１−メチルプロピル基、ｔ−ブチル基等の炭素数１〜４の直鎖状、分岐状または環状のアルキル基で置換した基等がある。これらのなかでも、ノルボルナン、トリシクロデカン、テトラシクロドデカン、アダマンタン、シクロペンタン、もしくはシクロヘキサン、またはこれらの脂環族環からなる基を炭素数１〜４の直鎖状、分岐状または環状のアルキル基で置換した基であることが好ましい。

In the above formula (7), R ′ represents a hydrogen atom, a methyl group or a trifluoromethyl group. R ⁹ represents each independently a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof or a linear or branched alkyl group having 1 to 4 carbon atoms, and at least R ⁹ One is the alicyclic hydrocarbon group or a derivative thereof, or any two R ^{9 's} are bonded to each other, and each is a divalent alicyclic ring having 4 to 20 carbon atoms together with the carbon atom to which each is bonded. Or a derivative thereof, wherein the remaining R ⁹ is a linear or branched alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms Represents.
In R ⁹ in the above formula (7), examples of the monovalent or divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane. Groups consisting of alicyclic rings such as norbornane, tricyclodecane, tetracyclododecane and adamantane; groups consisting of these alicyclic rings are methyl, ethyl, n-propyl, i-propyl, Examples thereof include a group substituted with a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms such as an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group and a t-butyl group. Among these, norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane, or cyclohexane, or a group consisting of these alicyclic rings is a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms. A group substituted with a group is preferred.

In R ⁹ in the above formula (7), examples of the derivative of a monovalent or divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include a hydroxyl group; a carboxyl group; an oxo group (that is, a ═O group). ); Hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxylethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3- A hydroxyalkyl group having 1 to 4 carbon atoms such as hydroxybutyl group and 4-hydroxybutyl group; methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1- C1-C4 alkoxyl groups such as methylpropoxy group and t-butoxy group; cyano group; cyanomethyl group, 2-cyanoethyl group, 3- There are compounds in which a monovalent or divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms is substituted with a substituent such as a cyanoalkyl group having 2 to 5 carbon atoms such as an anopropyl group or 4-cyanobutyl group. . Among these, a compound in which a monovalent or divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms is substituted with a hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, or a cyanomethyl group is preferable. .
In R ⁹ in the above formula (7), examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and n-butyl. Group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like. Among these, a methyl group, an ethyl group, an n-propyl group, and an i-propyl group are preferable.

  The repeating unit (a-2) having an acid dissociable group is preferably a repeating unit represented by the following formula (7-1) to formula (7-4).

上記式（７−１）〜式（７−４）において、Ｒ’は水素原子またはメチル基を表し、Ｒ^9'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表す。また、式（７−３）において、ｍ’は０〜４の整数である。上記炭素数１〜４の直鎖状または分岐状のアルキル基としては、例えば、メチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基、ｎ−ブチル基、２−メチルプロピル基、１−メチルプロピル基、ｔ−ブチル基等がある。これらのなかでも、メチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基であることが好ましい。
また、酸解離性基を有する繰り返し単位（ａ−２）が式（７−１）の場合には、２個のＲ^9'がともにメチル基であることが特に好ましい。繰り返し単位（ａ−２）が上記式（７−３）の場合には、ｍ’は０または１の整数であり、且つ、Ｒ^9'はメチル基またはエチル基であることが特に好ましい。繰り返し単位（ａ−２）が上記式（７−４）の場合には、２個のＲ^9'がともにメチル基であることが特に好ましい。

In the above formulas (7-1) to (7-4), R ′ represents a hydrogen atom or a methyl group, and R ^{9 ′} is independently a linear or branched group having 1 to 4 carbon atoms. Represents an alkyl group. Moreover, in Formula (7-3), m 'is an integer of 0-4. Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, 1- Examples include a methylpropyl group and a t-butyl group. Among these, a methyl group, an ethyl group, an n-propyl group, and an i-propyl group are preferable.
Further, when the repeating unit (a-2) having an acid dissociable group is represented by the formula (7-1), it is particularly preferable that both R ^{9 ′} are methyl groups. When the repeating unit (a-2) is the above formula (7-3), it is particularly preferable that m ′ is an integer of 0 or 1, and R ^{9 ′} is a methyl group or an ethyl group. In the case where the repeating unit (a-2) is the above formula (7-4), it is particularly preferable that both of R ^{9 ′} are methyl groups.

Moreover, the repeating unit (a-2) which has an acid dissociable group can contain the repeating unit represented by following formula (7-5)-Formula (7-12). R ′ represents a hydrogen atom or a methyl group.

  The main chain skeleton of the repeating unit (a-2) is not particularly limited, but is preferably a main chain skeleton having a (meth) acrylate ester structure or an α-trifluoroacrylate ester structure. In the present specification, “(meth) acrylic acid ester” means “acrylic acid ester or methacrylic acid ester”.

Specific examples of the monomer constituting the repeating unit (a-2) include (meth) acrylic acid 2-methyladamantyl-2-yl ester and (meth) acrylic acid 2-methyl-3-hydroxyadamantyl-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 (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) methyl-8-acrylic acid tricyclo [5.2.1.0 ^2,6] decan-8-yl ester, (meth) -8-acrylate Echirutorishi B [5.2.1.0 ^2,6] decan-8-yl ester, (meth) methyl-4-acrylate tetracyclo [6.2.1 ^3,6. 0 ^2,7 ] dodecan-4-yl ester, (meth) acrylic acid-4-ethyltetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl ester, (meth) acrylic acid 1- (bicyclo [2.2.1] hept-2-yl) -1-methylethyl ester, (meth) acrylic acid 1- ( Tricyclo [5.2.1.0 ^2,6 ] decan-8-yl) -1-methylethyl ester, (meth) acrylic acid 1- (tetracyclo [6.2.1 ^3,6 .0 ^2,7 ] Dodecan-4-yl) -1-methyl ethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methyl ethyl ester, (meth) acrylic acid 1,1-dicyclohexylethyl ester, (meth ) Acrylic acid 1,1-di (bicyclo [2.2.1] hept-2-yl) ethyl ester, (meth) acrylic acid 1,1-di (tricyclo [5.2.1.0 ^2,6 ] Decan-8-yl) ethyl ester, (meth) acte Acrylic acid 1,1-di (tetracyclo [6.2.1 ^3,6 .0 ^2,7] dodecane-4-yl) ethyl ester, (meth) acrylic acid 1,1-di (adamantan-1-yl) Ethyl ester, (meth) acrylic acid 1-methyl-1-cyclopentyl ester, (meth) acrylic acid 1-ethyl-1-cyclopentyl ester, (meth) acrylic acid 1-methyl-1-cyclohexyl ester, (meth) acrylic acid Examples thereof include 1-ethyl-1-cyclohexyl ester.

Among these, (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid 2-ethyladamantyl-2-yl 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 1- (bicyclo [2.2.1] hept -2-yl) -1-methylethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1-methyl-1-cyclopentyl ester, (meth) 1-ethyl-1-cyclopentyl acrylate, 1-methyl-1-cyclohexyl (meth) acrylate, 1-ethyl (meth) acrylate - it is preferable to use a cyclohexyl ester.
In addition, the monomer which produces | generates a repeating unit (a-2) can be used individually or in mixture.

The resin (A) further has one or more types of repeating units other than the repeating unit (a-1) and the repeating unit (a-2) described above (hereinafter sometimes referred to as “other repeating units”). You may do it.
The other repeating units include repeating units represented by the following formulas (8-1) to (8-6) (hereinafter sometimes referred to as “other repeating units (a-3)”), and the following formula (9 ) (Hereinafter sometimes referred to as “other repeating unit (a-4)”), a repeating unit represented by the following formula (10) (hereinafter referred to as “other repeating unit (a-5)”. ) ”), And a repeating unit represented by the following formula (11) (hereinafter, also referred to as“ other repeating unit (a-6) ”) can be given as preferred examples.

上記式（８−１）〜（８−６）の各式において、Ｒ¹は互いに独立して、水素原子、メチル基、またはトリフルオロメチル基を表し、Ｒ¹⁰は水素原子、または置換基を有してもよい炭素数１〜４のアルキル基を表し、Ｒ¹¹は水素原子、またはメトキシ基を表す。また、Ａは単結合またはメチレン基を表し、Ｂは酸素原子またはメチレン基を表す。ｌは１〜３の整数であり、ｐは０または１である。 Other repeating units (a-3) are represented by the following formulas (8-1) to (8-6).

In the above formulas (8-1) to (8-6), R ¹ independently represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ¹⁰ represents a hydrogen atom or a substituent. Represents an optionally substituted alkyl group having 1 to 4 carbon atoms, R ¹¹ 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 is an integer of 1 to 3, and p is 0 or 1.

Among the monomers giving another repeating unit (a-3), (meth) acrylic acid-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nona is preferable. -2-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-5, 5-dimethyl-2-oxotetrahydrofuran-4-yl ester, (meth) acrylic acid-3,3-dimethyl-2-oxotetrahydrofuran-4-yl ester, (meth) acrylic acid-2-oxotetrahydrofuran-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, (meth) acrylic acid-4,4-dimethyl-5- Mention may be made of oxotetrahydrofuran-2-ylmethyl ester.
In addition, the monomer which gives a repeating unit (a-3) can be used individually or in mixture.

上記式（９）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、Ｒ¹²は炭素数７〜２０の多環型脂環式炭化水素基を表す。この炭素数７〜２０の多環型脂環式炭化水素基は、炭素数１〜４のアルキル基、ヒドロキシル基、シアノ基、および炭素数１〜１０のヒドロキシアルキル基からなる群より選択される少なくとも一種で置換されていても、置換されていなくてもよい。
炭素数７〜２０の多環型脂環式炭化水素基としては、例えば、ビシクロ［２．２．１］ヘプタン、ビシクロ［２．２．２］オクタン、トリシクロ［５．２．１．０^2,6］デカン、テトラシクロ［６．２．１．１^3,6．０^2,7］ドデカン、トリシクロ［３．３．１．１^3,7］デカン等のシクロアルカン類に由来する脂環族環からなる炭化水素基を挙げることができる。 The other repeating unit (a-4) is represented by the following formula (9).

In the above formula (9), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ¹² represents a polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms. The polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms is 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 at least 1 type, it does not need to be substituted.
Examples of the polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms 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. , 1-methylpropyl group, t-butyl group and the like, or a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms may be substituted with one or more. 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, hydroxyalkyl groups having 1 to 10 carbon atoms, carboxyls The group may be substituted with oxygen.
Among the monomers giving other repeating units (a-4), (meth) acrylic acid-bicyclo [2.2.1] heptyl ester, (meth) acrylic acid-cyclohexyl ester, ( (Meth) 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 . And ^0,7 ] dodecanyl ester, (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 ] decanyl ester, and the like.
In addition, the monomer which gives a repeating unit (a-4) can be used individually or in mixture.

上記式（１０）において、Ｒ¹⁴は水素原子、炭素数１〜４のアルキル基、トリフルオロメチル基、またはヒドロキシメチル基を表し、Ｒ¹³は、２価の鎖状または環状の炭化水素基を表す。 Another repeating unit (a-5) is represented by the following formula (10).

In the above formula (10), R ¹⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, or a hydroxymethyl group, and R ¹³ represents a divalent chain or cyclic hydrocarbon group. Represent.

R ¹³ of the other repeating unit (a-5) represented by the above formula (10) is a divalent chain or cyclic hydrocarbon group as described above, and examples thereof include an alkylene glycol group and an alkylene ester group. It may be. Preferred R ¹³ is 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, Insalen 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; 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 and the like.

Among the monomers giving other repeating units (a-5), (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-3-propyl) is preferable. ) Ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2) -Trifluoromethyl-2-hydroxy-5-pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester, (meth) acrylic Acid 2-{[5- (1 ′, 1 ′, 1′-trifluoro-2′-trifluoromethyl-2′-hydroxy) propyl] bicyclo [2.2.1] heptyl} ester, (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 and the like.
In addition, the monomer which gives a repeating unit (a-5) can be used individually or in mixture.

上記式（１１）において、Ｒ¹⁵は水素原子またはメチル基を表し、Ｙは互いに独立して、単結合または炭素数１〜３の２価の有機基を表し、Ｒ¹⁷は単結合または炭素数１〜３の２価の有機基を表し、Ｒ¹⁶は互いに独立して、水素原子、水酸基、シアノ基、または−ＣＯＯＲ¹⁸基を表す。但し、Ｒ¹⁸は水素原子、炭素数１〜４の直鎖状もしくは分岐状のアルキル基、または炭素数３〜２０の脂環式のアルキル基を表す。上記式（１１）においては、３つのＲ¹⁶のうち少なくとも１つは水素原子でなく、且つＹが単結合のときは、３つのＹのうち少なくとも１つは炭素数１〜３の２価の有機基であることが好ましい。 The other repeating unit (a-6) is represented by the following formula (11).

In the above formula (11), R ¹⁵ represents a hydrogen atom or a methyl group, Y independently represents a single bond or a divalent organic group having 1 to 3 carbon atoms, and R ¹⁷ represents a single bond or a carbon number. 1 to 3 represent a divalent organic group, and R ¹⁶ independently represents a hydrogen atom, a hydroxyl group, a cyano group, or a —COOR ¹⁸ group. R ¹⁸ represents 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. In the above formula (11), at least one of the three R ¹⁶ is not a hydrogen atom, and when Y is a single bond, at least one of the three Y is a divalent having 1 to 3 carbon atoms. An organic group is preferred.

In another repeating unit (a-6) represented by the formula (11), the divalent organic group having 1 to 3 carbon atoms represented by R ¹⁷ and Y includes a methylene group, an ethylene group, and a propylene group. Can be mentioned.
Among the groups represented by R ¹⁸ of the COOR ¹⁸ group constituting the group represented by R ¹⁶ in the formula (11), specifically, as a linear or branched alkyl group having 1 to 4 carbon atoms, Can include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, and a t-butyl group. In addition, as the alicyclic alkyl group having 3 to 20 carbon atoms, for example, a cycloalkyl group having 3 to 20 carbon atoms, a polycyclic alicyclic alkyl group, or a linear form of these cyclic alkyl groups, There are groups substituted with branched or cyclic alkyl groups. More specifically, examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic alkyl group include a bicyclo [2.2.1] heptyl group, a tricyclo [5.2.1.0 ^2,6 ] decyl group, and a tetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecanyl group, adamantyl group and the like.

Specific examples of the monomer that gives the repeating unit (a-6) include (meth) acrylic acid 3-hydroxyadamantan-1-yl ester and (meth) acrylic acid 3,5-dihydroxyadamantan-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-methyladamantane-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, (meth) acrylic Acid 3-hydroxy-5,7-dimethyladamantan-1-ylmethyl ester, etc. It can gel.
In addition, the monomer which gives a repeating unit (a-6) can be used individually or in mixture.

Moreover, resin (A) contained in the radiation sensitive resin composition of this invention is the said repeating unit (a-1) and (a-2), and other repeating units (a-3)-(a-6). ) May be further included (hereinafter also referred to as “another repeating unit”).
Examples of such other repeating units include (meth) acrylic acid esters having a bridged hydrocarbon skeleton such as dicyclopentenyl (meth) acrylate and adamantylmethyl (meth) acrylate; Carboxyl group-containing esters having a bridged hydrocarbon skeleton of an unsaturated carboxylic acid such as carboxynorbornyl acrylate, carboxytricyclodecanyl (meth) acrylate, carboxytetracycloundecanyl (meth) acrylate; 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, (meth ) 2-hydroxypropyl acrylate, 3-hydroxypropyl (meth) acrylate, cyclopropyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, 4-methoxycyclohexyl (meth) acrylate, It also has a bridged hydrocarbon skeleton such as 2-cyclopentyloxycarbonylethyl (meth) acrylate, 2-cyclohexyloxycarbonylethyl (meth) acrylate, 2- (4-methoxycyclohexyl) oxycarbonylethyl (meth) acrylate, etc. (Meth) acrylic esters; α-hydroxy such as methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, n-propyl α-hydroxymethyl acrylate, n-butyl α-hydroxymethyl acrylate, etc. Methyla Unsaturated nitrile compounds such as (meth) acrylonitrile, α-chloroacrylonitrile, crotonnitrile, maleinonitrile, fumaronitrile, mesacononitrile, citracononitrile, itaconnitrile; (meth) acrylamide, N, N-dimethyl ( Unsaturated amide compounds such as (meth) acrylamide, crotonamide, maleinamide, fumaramide, mesaconamide, citraconamide, itaconamide; N- (meth) acryloylmorpholine, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, vinylpyridine, Other nitrogen-containing vinyl compounds such as vinylimidazole; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride Unsaturated carboxylic acids (anhydrides) such as mesaconic acid; 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, (meth) acrylic acid 4 -Carboxy group-containing esters having no bridged hydrocarbon skeleton of unsaturated carboxylic acid such as carboxybutyl, 4-carboxycyclohexyl (meth) acrylate; 1,2-adamantanediol di (meth) acrylate, 1, A polyfunctional monomer having a bridged hydrocarbon skeleton such as 3-adamantanediol di (meth) acrylate, 1,4-adamantanediol di (meth) acrylate, tricyclodecanyldimethylol di (meth) acrylate; Methylene glycol di (meth) acrylate, ethylene glycol di (meth) acryl 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, 1,3-bis (2-hydroxypropyl) benzenedi (meth) acrylate, etc. Examples thereof include a unit in which a polymerizable unsaturated bond of a polyfunctional monomer such as a polyfunctional monomer having no bridged hydrocarbon skeleton is cleaved.

  The content of the repeating unit (a-1) contained in the resin (A) is preferably 10 to 90 mol%, and preferably 20 to 80 mol%, based on all repeating units constituting the polymer. Is more preferable, and it is especially preferable that it is 30-70 mol%. If the content of the repeating unit (a-1) is less than 10 mol%, developability and defect performance as a resist pattern may be deteriorated. On the other hand, when the content of the repeating unit (a-1) is more than 90 mol%, the resolution as a resist pattern, LWR, and PEB temperature dependency may be deteriorated.

  The content of the repeating unit (a-2) contained in the resin (A) is preferably 10 to 85 mol%, more preferably 20 to 80 mol%, based on all repeating units, and 30 It is especially preferable that it is -70 mol%. When the content of the repeating unit (2) is less than 10 mol%, the resolution as a resist, LWR, and PEB temperature dependency may deteriorate. On the other hand, if the content of the repeating unit (a-2) is more than 85 mol%, the developability and defect performance as a resist may deteriorate.

The other repeating units (a-3) to (a-6) contained in the resin (A) and the above-mentioned further repeating units are optional components. For example, the repeating unit (a-3) The content of is preferably 30 mol% or less, more preferably 25 mol% or less, and particularly preferably 15 mol% or less, based on all repeating units. If the content of the repeating unit (a-3) is more than 30 mol%, the defect performance as a resist may be deteriorated. In addition, although the minimum of the content rate of a repeating unit (a-3) is not specifically limited, When necessary, 5 mol% or more is preferable.
Similarly, it is preferable that the content rate of the other repeating unit (a-4) contained in resin (A) is 30 mol% or less with respect to all the repeating units, and it is further 25 mol% or less. Preferably, it is particularly preferably 15 mol% or less. If the content of the repeating unit (a-4) is more than 30 mol%, the resist film may be easily swollen by an alkali developer, or developability as a resist may be lowered. In addition, although the minimum of the content rate of a repeating unit (a-4) is not specifically limited, When necessary, 5 mol% or more is preferable.
The content of other repeating units (a-5) contained in the resin (A) is preferably 30 mol% or less, more preferably 25 mol% or less, based on all repeating units, and 20 It is particularly preferable that the amount is not more than mol%. When the content of the repeating unit (a-5) is more than 30 mol%, the top loss of the resist pattern may occur and the pattern shape may deteriorate.
The content of other repeating units (a-6) contained in the resin (A) is usually preferably 30 mol% or less, more preferably 25 mol% or less, based on all repeating units. , 20 mol% or less is particularly preferable. If the content of the repeating unit (a-6) is more than 30 mol%, the resist film may be easily swollen by an alkali developer or the developability as a resist may be lowered.
The content of other repeating units contained in the resin (A) is preferably 50 mol% or less, more preferably 40 mol% or less, and more preferably 30 mol% or less, based on all repeating units. It is particularly preferred that

Next, the manufacturing method of resin (A) demonstrated until now is demonstrated.
The resin (A) can be synthesized according to a conventional method such as radical polymerization, and includes, for example, a monomer constituting a repeating unit (hereinafter referred to as “monomer”) and a radical initiator. The reaction solution is dropped into a reaction solvent or a reaction solution containing a monomer to cause a polymerization reaction, or a reaction solution containing each monomer and a reaction solution containing a radical initiator are separately added to the reaction solvent. Alternatively, it is dropped into a reaction solution containing a monomer to cause a polymerization reaction, and further, a reaction solution prepared separately for each monomer and a reaction solution containing a radical initiator are separately added to the reaction solvent. Alternatively, a method in which a polymerization reaction is carried out by dropping into a reaction solution containing a monomer is preferable.

  The reaction temperature in each of the above reactions can be appropriately set depending on the type of initiator to be used. For example, it is generally 30 ° C to 180 ° C. In addition, it is preferable that the reaction temperature in said each reaction is 40 to 160 degreeC, and it is still more preferable that 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 it is preferably 30 minutes to 8 hours, more preferably 45 minutes to 6 hours. It is particularly preferred that the time is 5 hours. The total reaction time including the dropping time can be variously set as described above, but is preferably 30 minutes to 8 hours, more preferably 45 minutes to 7 hours, and 1 hour to 6 hours. It is particularly preferred. When dripping into the solution containing the monomer, the content ratio of the monomer in the dripped solution is preferably 30 mol% or more, more preferably 50 mol% or more based on the total amount of monomers used for the polymerization. More preferably, it is particularly preferably 70 mol% or more.

  As radical initiators used for polymerization of the resin (A), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropylpropionitrile) ), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile (AIBN), dimethyl-2,2′-azobis (isobutyrate) (MAIB), 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-imidazoline-2- Propane) dihydrochloride, 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) 2-hydroxyethyl] propionamide}, dimethyl-2,2′-azobis (2- Methyl propionate), 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2- (hydroxymethyl) propionitrile), and the like. These initiators can be used alone or in admixture of two or more.

As a solvent used for the polymerization, any solvent can be used as long as it does not dissolve the monomer used and inhibits the polymerization. Examples of the solvent that inhibits polymerization include solvents that prohibit polymerization, such as nitrobenzenes, and solvents that cause chain transfer, such as mercapto compounds.
Examples of the solvent that can be suitably used for the polymerization include alcohols, ethers, ketones, amides, esters and lactones, nitriles, and a mixture of these solvents. 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. Examples of 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 a powder. Examples of the reprecipitation solvent include water, alcohols, ethers, ketones, amides, esters and lactones, nitriles, and a mixture of these solvents. 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. Examples of esters and lactones include ethyl acetate, methyl acetate, isobutyl acetate, and γ-butyrolactone. Examples of nitriles include acetonitrile, propionitrile, and butyronitrile.

Radiation sensitive acid generator (B):
The radiation-sensitive acid generator (B) (hereinafter sometimes simply referred to as “acid generator (B)”) contained in the radiation-sensitive resin composition of the present invention generates an acid upon exposure. Functions as a photoacid generator. This acid generator uses an acid generated by exposure to dissociate an acid-dissociable group present in the resin (A) contained in the radiation-sensitive resin composition (eliminate a protective group), and (A) is alkali-soluble. As a result, the exposed portion of the resist film becomes readily soluble in an alkaline developer, thereby forming a positive resist pattern.
The acid generator (B) includes a radiation sensitive acid generator (b-1) containing a compound represented by the above formula (2) and a radiation sensitive acid containing a compound represented by the formula (2 ′). What contains at least 1 chosen from a generator (b-2) is preferable. Hereinafter, the acid generator represented by the above formulas (2) and (2 ′) will be described.

In the above formula (2), R ³ is fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, straight-chain or branched alkoxy group having 1 to 10 carbon atoms, or carbon represents a straight or branched alkoxycarbonyl group having 2 to 11, 'in, R 3 formula ^(2)' is a hydrogen atom, a fluorine atom, a hydroxyl group, a straight or branched An alkyl group, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or a linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms is represented.
Specific examples of the linear or branched alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, etc. Can be mentioned. Among these, a methyl group, an ethyl group, an n-butyl group, and a t-butyl group are preferable.
Specific examples of the linear or branched alkoxyl group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group , N-decyloxy group and the like. Among these, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group and the like are preferable.
Specific examples of the linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms include methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, i-propoxycarbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, n-heptyloxycarbonyl group, n-octyl An oxycarbonyl group, 2-ethylhexyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group, etc. can be mentioned. Among these, a methoxycarbonyl group, an ethoxycarbonyl group, and an n-butoxycarbonyl group are preferable.

In the above formulas (2) and (2 ′), R ⁴ is a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or carbon A linear, branched or cyclic alkanesulfonyl group having a number of 2 to 11 is represented.
The linear or branched alkyl group having 1 to 10 carbon atoms and the linear or branched alkoxyl group having 1 to 10 carbon atoms are specifically represented as R ³ and R ^{3 ′.} Examples thereof are the same as those exemplified above.
Specific examples of the linear, branched or cyclic alkanesulfonyl group having 2 to 11 carbon atoms include ethanesulfonyl group, n-propylsulfonyl group, n-butylsulfonyl group, tert-butylsulfonyl group, n- Pentylsulfonyl group, neopentylsulfonyl group, n-hexylsulfonyl group, n-heptylsulfonyl group, n-octylsulfonyl group, 2-ethylhexanesulfonyl group, n-nonylsulfonyl group, n-decylsulfonyl group, cyclopentanesulfonyl group Group, cyclohexanesulfonyl group and the like. Among these, an ethanesulfonyl group, an n-propylsulfonyl group, an n-butylsulfonyl group, a cyclopentanesulfonyl group, and a cyclohexanesulfonyl group are preferable.

In the above formulas (2) and (2 ′), R ⁵ is independently a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group or naphthyl group, or 2 R ⁵ are bonded to each other to form a divalent group having 2 to 10 carbon atoms, and the divalent group may be substituted.
Specific examples of the linear or branched alkyl group having 1 to 10 carbon atoms include the same groups as those exemplified for the groups represented by R ³ and R ^{3 ′} .
Specific examples of the optionally substituted phenyl group include a phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl group, 4-ethylphenyl group, 4- Alkyl substitution in which a phenyl group such as t-butylphenyl group, 4-cyclohexylphenyl group, 4-fluorophenyl group, or the like, or a phenyl, linear or branched alkyl group having 1 to 10 carbon atoms is substituted for these phenyl groups Phenyl group; these phenyl group or alkyl-substituted phenyl group can be converted into hydroxyl group, carboxyl group, cyano group, nitro group, alkoxyl group, alkoxy group, Alkyl group, an alkoxycarbonyl group, group and a substituent such as an alkoxycarbonyl group, and the like. Among these, a phenyl group, a 4-cyclohexylphenyl group, a 4-t-butylphenyl group, a 4-methoxyphenyl group, and a 4-t-butoxyphenyl group are preferable.
Here, as the alkoxyalkyl group, specifically, a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, a 1-ethoxyethyl group, a 2-ethoxyethyl group, etc. 21 linear, branched or cyclic alkoxyalkyl groups may be mentioned. Specific examples of the alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, i-propoxycarbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, Examples thereof include linear, branched or cyclic alkoxycarbonyl groups having 2 to 21 carbon atoms such as t-butoxycarbonyl group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl and the like. Specific examples of the alkoxycarbonyloxy group include methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, i-propoxycarbonyloxy group, n-butoxycarbonyloxy group, t-butoxycarbonyloxy group, cyclopentyl. Examples thereof include linear, branched or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms such as oxycarbonyl group and cyclohexyloxycarbonyl.

Among the groups represented by R ⁵ in the above formulas (2) and (2 ′), as the optionally substituted naphthyl group, specifically, a 1-naphthyl group and a 2-methyl-1-naphthyl group 3-methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 5-methyl-1-naphthyl group, 6-methyl-1-naphthyl group, 7-methyl- 1-naphthyl group, 8-methyl-1-naphthyl group, 2,3-dimethyl-1-naphthyl group, 2,4-dimethyl-1-naphthyl group, 2,5-dimethyl-1-naphthyl group, 2,6 -Dimethyl-1-naphthyl group, 2,7-dimethyl-1-naphthyl group, 2,8-dimethyl-1-naphthyl group, 3,4-dimethyl-1-naphthyl group, 3,5-dimethyl-1-naphthyl Group, 3,6-dimethyl-1-naphthyl group, 3,7-dimethyl -1-naphthyl group, 3,8-dimethyl-1-naphthyl group, 4,5-dimethyl-1-naphthyl group, 5,8-dimethyl-1-naphthyl group, 4-ethyl-1-naphthyl group 2-naphthyl Group, 1-methyl-2-naphthyl group, 3-methyl-2-naphthyl group, naphthyl group such as 4-methyl-2-naphthyl group, etc., or these naphthyl groups are linear or branched having 1 to 10 carbon atoms Alkyl-substituted naphthyl groups substituted with a cyclic or cyclic alkyl group; these naphthyl groups or alkyl-substituted naphthyl groups can be converted into hydroxyl groups, carboxyl groups, cyano groups, nitro groups, alkoxyl groups, alkoxyalkyl groups, alkoxycarbonyl groups, alkoxycarbonyl groups. Examples include a group substituted with a substituent such as an oxy group. Among these, 1-naphthyl group, 1- (4-methoxynaphthyl) group, 1- (4-ethoxynaphthyl) group, 1- (4-n-propoxynaphthyl) group, 1- (4-n-butoxy) Naphthyl) group, 2- (7-methoxynaphthyl) group, 2- (7-ethoxynaphthyl) group, 2- (7-n-propoxynaphthyl) group, 2- (7-n-butoxynaphthyl) group Is preferred.
Here, as the alkoxyalkyl group, alkoxycarbonyl group and alkoxycarbonyloxy group substituted on the naphthyl group or alkyl-substituted naphthyl group, specifically, the alkoxyalkyl group substituted on the phenyl group or the alkyl-substituted phenyl group, alkoxycarbonyl group and The thing similar to what was illustrated by the alkoxycarbonyloxy group is mentioned.

Among the groups represented by R ⁵ in the above formulas (2) and (2 ′), the divalent group having 2 to 10 carbon atoms formed by bonding two R ⁵ to each other includes the formula ( It is preferably a 5- or 6-membered divalent group including a sulfur atom in 2) and (2 ′), and more preferably a divalent group of a 5-membered ring (ie, tetrahydrothiophene ring). preferable. Specific examples of the substituent that substitutes the divalent group include the same substituents as those exemplified as the substituent that substitutes the phenyl group or the alkyl-substituted phenyl group.
Moreover, in said formula (2) and (2 '), k is an integer of 0-2 and r is an integer of 0-10.

  That is, as the cation moiety of the acid generator represented by any one of the above formulas (2) and (2 ′), specifically, a triphenylsulfonium cation, a tri-1-naphthylsulfonium cation, tri-tert-butyl Phenylsulfonium cation, 4-fluorophenyl / diphenylsulfonium cation, di-4-fluorophenyl / phenylsulfonium cation, tri-4-fluorophenylsulfonium cation, 4-cyclohexylphenyl / diphenylsulfonium cation, 4-methanesulfonylphenyl / diphenylsulfonium cation Cation, 4-cyclohexanesulfonyl diphenylsulfonium cation, 1-naphthyldimethylsulfonium cation, 1-naphthyldiethylsulfonium cation, 1- (4-hydroxy Phthalen-1-yl) dimethylsulfonium cation, 1- (4-methylnaphthalen-1-yl) dimethylsulfonium cation, 1- (4-methylnaphthalen-1-yl) diethylsulfonium cation, 1- (4-cyanonaphthalene- 1-yl) dimethylsulfonium cation, 1- (4-cyanonaphthalen-1-yl) diethylsulfonium cation, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium cation, 1- (4-methoxy Naphthalen-1-yl) tetrahydrothiophenium cation, 1- (4-ethoxynaphthalen-1-yl) tetrahydrothiophenium cation, 1- (4-n-propoxynaphthalen-1-yl) tetrahydrothiophenium cation, 1- (4-n-Butoxyna Talen-1-yl) tetrahydrothiophenium cation, 2- (7-methoxynaphthalen-2-yl) tetrahydrothiophenium cation, 2- (7-ethoxynaphthalen-2-yl) tetrahydrothiophenium cation, 2- (7-n-propoxynaphthalen-2-yl) tetrahydrothiophenium cation, 2- (7-n-butoxynaphthalen-2-yl) tetrahydrothiophenium cation and the like can be mentioned.

In the above formulas (2) and (2 ′), X ⁻ is any one of the above formulas (3) to (6). When X ⁻ is an anion represented by the above formula (3), two R ⁵ in the formulas (2) and (2 ′) are bonded to each other to form a divalent group having 2 to 10 carbon atoms. Never do.
In the above formula (3), when it is an anion of the formula (2), R ⁶ represents a hydrogen atom, a fluorine atom, or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, and n is 1 to 10 When R ⁶ is an anion of formula (2 ′), R ⁶ represents a hydrogen atom or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, and n is an integer of 1 to 10. .
Examples of the hydrocarbon group having 1 to 12 carbon atoms that may be substituted include an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, and a bridged alicyclic hydrocarbon group. More specifically, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group Group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, norbornyl group, norbornylmethyl group, hydroxynorbornyl group, adamantyl Groups and the like.
The —C _n F _2n — group is a linear or branched perfluoroalkylene group having n carbon atoms. Here, n is preferably an integer of 1, 2, 4 or 8.

In the above formula (4), R ⁷ is substituted with an alkylcarbonyl group having 1 to 6 carbon atoms, an alkylcarbonyloxy group or a hydroxyalkyl group, or represents an unsubstituted hydrocarbon group having 1 to 12 carbon atoms.
Examples of the substituted or unsubstituted hydrocarbon group having 1 to 12 carbon atoms include the same groups as those exemplified for R ⁶ , and these groups include alkylcarbonyl groups and alkylcarbonyloxy groups having 1 to 6 carbon atoms. Alternatively, it is a hydrocarbon group substituted with a hydroxyalkyl group.
Examples of the alkylcarbonyl group having 1 to 6 carbon atoms include a methylcarbonyl group, an ethylcarbonyl group, a propylcarbonyl group, and a butylcarbonyl group. Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, Examples of hydroxyalkyl groups such as propylcarbonyloxy group and butylcarbonyloxy group include hydroxymethyl group, hydroxyethyl group, hydroxypropyl group, hydroxybutyl group and the like.

In the above formulas (5) and (6), R ⁸ is independently of each other an alkyl group containing a linear or branched fluorine atom having 1 to 10 carbon atoms, or two R ⁸ are bonded. Represents a divalent group which may be substituted and contains a fluorine atom having 2 to 10 carbon atoms.
Specific examples of the alkyl group containing a linear or branched fluorine atom having 1 to 10 carbon atoms include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, and dodecafluoro. A pentyl group, a perfluorooctyl group, etc. can be mentioned.
Further, as a substituted or unsubstituted divalent group containing a fluorine atom having 2 to 10 carbon atoms formed by bonding two R ⁸ , specifically, a tetrafluoroethylene group, a hexafluoropropylene group , Octafluorobutylene group, decafluoropentylene group, undecafluorohexylene group and the like.

  That is, as an anion site of the acid generator represented by any one of the formulas (2) and (2 ′), specifically, a trifluoromethanesulfonate anion, a perfluoro-n-butylsulfonate anion, a perfluoro-n— Octylsulfonate anion, 2- (bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoroethylsulfonate anion, 2- (bicyclo [2.2.1] hepta-2 -Yl) -1,1-difluoroethylsulfonate anion, 1-adamantylsulfonate anion, anions represented by the following formulas (2-1) to (2-7), and the like.

Various radiation-sensitive acid generators containing a compound represented by the above formula (2) and / or (2 ′) are conceivable depending on the combination of a cation and an anion, but the combination is not particularly limited. Moreover, the radiation sensitive resin composition of this invention may contain a single radiation sensitive acid generator, and may contain 2 or more types of radiation sensitive acid generators.
However, as the radiation-sensitive acid generator represented by the formulas (2) and (2 ′), specifically, a 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium cation, 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium cation, 1- (4-ethoxynaphthalen-1-yl) tetrahydrothiophenium cation, 1- (4-n-propoxynaphthalen-1-yl) tetrahydrothio Phenium cation, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium cation, 2- (7-methoxynaphthalen-2-yl) tetrahydrothiophenium cation, 2- (7-ethoxynaphthalene- 2-yl) tetrahydrothiophenium cation, 2- (7-n-propoxynaphthalen-2-i) E) two R ⁵ groups such as tetrahydrothiophenium cation, 2- (7-n-butoxynaphthalen-2-yl) tetrahydrothiophenium cation and the like, which are substituted or unsubstituted having 2 to 10 carbon atoms Radiation-sensitive acid by a combination of a cation having a divalent group and an anion represented by the above formula (3) such as trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, etc. No generator is contained.

  The amount of the radiation-sensitive acid generator (B) used is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the resin (A) from the viewpoint of ensuring the sensitivity and developability as a resist. 0.5 to 15 parts by mass, more preferably 0.5 to 10 parts by mass. If the amount used is less than 0.1 parts by mass, the sensitivity and developability may be lowered. On the other hand, if the amount used exceeds 20 parts by mass, the transparency to radiation may be reduced, making it difficult to obtain a rectangular resist pattern.

The radiation-sensitive resin composition of the present invention comprises a radiation-sensitive acid generator other than the radiation-sensitive acid generator containing the compounds represented by formulas (2) and (2 ′) (hereinafter “other sensitivity”). A radiation acid generator ").
The use ratio of the other radiation sensitive acid generator is preferably 80% by mass or less, more preferably 60% by mass or less, and more preferably 50% by mass or less with respect to all the radiation sensitive acid generators. It is particularly preferred that In addition, although the minimum of the usage-amount of another radiation sensitive acid generator is not specifically limited, When necessary, it is 5 mass% or more.

Examples of other radiation-sensitive acid generators include onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, and sulfonic acid compounds. In addition, another radiation sensitive acid generator may be used independently and may be used in combination of 2 or more type.
Examples of onium salt compounds include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like. Specific examples of the onium salt compounds include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta. 2-yl-1,1,2,2-tetrafluoroethanesulfonate, 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 − Trifluoroethanesulfonate, cyclohexyl, 2-oxocyclohexyl, methylsulfonium trifluoromethanesulfonate, dicyclohexyl, 2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium trifluoromethanesulfonate, 1- (3,5-dimethyl-4- Hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-butyl sulfonate, 1- (3,5-dimethyl-4- Hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octylsulfonate, 1- (4-methoxynaphthalen-1-yl) teto Hydrothiophenium trifluoromethanesulfonate, 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-butylsulfonate, 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro -N-octylsulfonate, 1- (4-ethoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-ethoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-butylsulfonate, 1- (4-Ethoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octyl sulfonate, 1- (4-n-propoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfone 1- (4-n-propoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-butylsulfonate, 1- (4-n-propoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n -Octyl sulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-butyl Sulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octyl sulfonate, 2- (7-methoxynaphthalen-2-yl) tetrahydrothiophenium trifluoromethanesulfonate, 2- (7-methoxy Phthalen-2-yl) tetrahydrothiophenium perfluoro-n-butyl sulfonate, 2- (7-methoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-octyl sulfonate, 2- (7-ethoxynaphthalene- 2-yl) tetrahydrothiophenium trifluoromethanesulfonate, 2- (7-ethoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-butylsulfonate, 2- (7-ethoxynaphthalen-2-yl) tetrahydrothio Phenium perfluoro-n-octyl sulfonate, 2- (7-n-propoxynaphthalen-2-yl) tetrahydrothiophenium trifluoromethanesulfonate, 2- (7-n-propoxynaphthalen-2-yl) tetrahydrothio Enium perfluoro-n-butylsulfonate, 2- (7-n-propoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-octylsulfonate, 2- (7-n-butoxynaphthalen-2-yl) Tetrahydrothiophenium trifluoromethanesulfonate, 2- (7-n-butoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-butylsulfonate, 2- (7-n-butoxynaphthalen-2-yl) tetrahydrothio Phenium perfluoro-n-octyl sulfonate and the like can be mentioned.

  Examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound. More specifically, (trichloromethyl) -s such as phenylbis (trichloromethyl) -s-triazine, 4-methoxyphenylbis (trichloromethyl) -s-triazine, 1-naphthylbis (trichloromethyl) -s-triazine, etc. -Triazine derivatives, 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane, etc. can be mentioned.

  Examples of the diazo ketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, a diazonaphthoquinone compound, and the like. More specifically, 1,2-naphthoquinonediazide of 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonylchloride, 2,3,4,4′-tetrahydroxybenzophenone 4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,1,1-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane or 1,2, -Naphthoquinonediazide-5-sulfonic acid ester etc. can be mentioned.

  Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds of these compounds. More specifically, 4-trisphenacylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, and the like can be given.

  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. More 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-octylsulfonylbicyclo [2.2.1]. Hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonylbicyclo [2.2.1] hept -5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyloxy) succini N- (nonafluoro-n-butylsulfonyloxy) succinimide, N- (perfluoro-n-octylsulfonyloxy) succinimide, N- (2-bicyclo [2.2.1] hept-2-yl-1, 1,2,2-tetrafluoroethanesulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate, 1,8-naphthalenedicarboxylic acid imidononafluoro-n-butylsulfonate, 1,8-naphthalenedicarboxylic acid imide Examples thereof include perfluoro-n-octyl sulfonate.

Nitrogen-containing compound (C):
The radiation sensitive resin composition of the present invention may further contain a nitrogen-containing compound (C) in addition to the resin (A) and the radiation sensitive acid generator (B) described so far. This nitrogen-containing compound (C) controls the diffusion phenomenon in the resist film of the acid generated from the acid generator upon exposure, and suppresses an undesirable chemical reaction in the non-exposed region. That is, this nitrogen-containing compound (C) functions as an acid diffusion controller. By blending the nitrogen-containing compound in this way, 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 exposure to heat treatment after exposure is increased. Since the change in the line width of the resist pattern due to the fluctuation of (PED) can be suppressed, a radiation-sensitive resin composition having extremely excellent process stability can be obtained.

  Examples of the nitrogen-containing compound (C) include a compound represented by the following formula (12) and other nitrogen-containing compounds. Among these, it is preferable that it is a compound represented by following formula (12).

式（１２）中においてＲ¹⁹およびＲ²⁰は、相互に独立に水素原子、直鎖状、分岐状もしくは環状の置換基されていてもよい炭素数１〜２０のアルキル基、アリール基またはアラルキル基、或いはＲ¹⁹同士或いはＲ²⁰同士が相互に結合して、それぞれが結合している炭素原子とともに炭素数４〜２０の２価の飽和或いは不飽和炭化水素基もしくはその誘導体を形成してもよい。
上記式（１２）で表される窒素含有化合物としては、例えば、Ｎ−ｔ−ブトキシカルボニルジ−ｎ−オクチルアミン、Ｎ−ｔ−ブトキシカルボニルジ−ｎ−ノニルアミン、Ｎ−ｔ−ブトキシカルボニルジ−ｎ−デシルアミン、Ｎ−ｔ−ブトキシカルボニルジシクロヘキシルアミン、Ｎ−ｔ−ブトキシカルボニル−１−アダマンチルアミン、Ｎ−ｔ−ブトキシカルボニル−２−アダマンチルアミン、Ｎ−ｔ−ブトキシカルボニル−Ｎ−メチル−１−アダマンチルアミン、（Ｓ）−（−）−１−（ｔ−ブトキシカルボニル）−２−ピロリジンメタノール、（Ｒ）−（＋）−１−（ｔ−ブトキシカルボニル）−２−ピロリジンメタノール、Ｎ−ｔ−ブトキシカルボニル−４−ヒドロキシピペリジン、Ｎ−ｔ−ブトキシカルボニルピロリジン、Ｎ，Ｎ'−ジ−ｔ−ブトキシカルボニルピペラジン、Ｎ，Ｎ−ジ−ｔ−ブトキシカルボニル−１−アダマンチルアミン、Ｎ，Ｎ−ジ−ｔ−ブトキシカルボニル−Ｎ−メチル−１−アダマンチルアミン、Ｎ−ｔ−ブトキシカルボニル−４，４'−ジアミノジフェニルメタン、Ｎ，Ｎ'−ジ−ｔ−ブトキシカルボニルヘキサメチレンジアミン、Ｎ，Ｎ，Ｎ'，Ｎ'−テトラ−ｔ−ブトキシカルボニルヘキサメチレンジアミン、Ｎ，Ｎ'−ジ−ｔ−ブトキシカルボニル−１，７−ジアミノヘプタン、Ｎ，Ｎ'−ジ−ｔ−ブトキシカルボニル−１，８−ジアミノオクタン、Ｎ，Ｎ'−ジ−ｔ−ブトキシカルボニル−１，９−ジアミノノナン、Ｎ，Ｎ'−ジ−ｔ−ブトキシカルボニル−１，１０−ジアミノデカン、Ｎ，Ｎ'−ジ−ｔ−ブトキシカルボニル−１，１２−ジアミノドデカン、Ｎ，Ｎ'−ジ−ｔ−ブトキシカルボニル−４，４'−ジアミノジフェニルメタン、Ｎ−ｔ−ブトキシカルボニルベンズイミダゾール、Ｎ−ｔ−ブトキシカルボニル−２−メチルベンズイミダゾール、Ｎ−ｔ−ブトキシカルボニル−２−フェニルベンズイミダゾール等のＮ−ｔ−ブトキシカルボニル基含有アミノ化合物等を挙げることができる。

In the formula (12), R ¹⁹ and R ²⁰ are each independently a hydrogen atom, a linear, branched or cyclic substituent having 1 to 20 carbon atoms, an aryl group or an aralkyl group. Alternatively, R ¹⁹ or R ²⁰ 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 is bonded. .
Examples of the nitrogen-containing compound represented by the formula (12) 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-butoxy Carbonyl-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-1,12-diamin Dodecane, N, N′-di-t-butoxycarbonyl-4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl Examples thereof include Nt-butoxycarbonyl group-containing amino compounds such as 2-phenylbenzimidazole.

In addition to the nitrogen-containing compound represented by the above formula (12), the nitrogen-containing compound (C) includes, for example, a tertiary amine compound, a quaternary ammonium hydroxide compound, a photodegradable base compound, and the like. A nitrogen heterocyclic compound etc. can be mentioned.
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, 2,6-diisopropylaniline; alkanolamines such as triethanolamine, N, N-di (hydroxyethyl) aniline; N, N , N ′, N′-Tetramethylethylenedi N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzenetetramethylenediamine, bis (2- Examples thereof include dimethylaminoethyl) ether and bis (2-diethylaminoethyl) ether.
Examples of the quaternary ammonium hydroxide compound include tetra-n-propylammonium hydroxide and tetra-n-butylammonium hydroxide.

上記式（１３−１）および（１３−２）におけるＲ²¹〜Ｒ²⁵は、相互に独立して、水素原子、アルキル基、アルコキシル基、ヒドロキシル基、またはハロゲン原子を表す。
また、Ｚ^-は、ＯＨ^-、Ｒ−ＣＯＯ^-、Ｒ−ＳＯ₃ ^-（但し、Ｒはアルキル基、アリール基、またはアルカノール基を表す）、または下記式（１４）で表されるアニオンを表す。 The photodegradable base compound is an onium salt compound that decomposes upon exposure and loses basicity as acid diffusion controllability.
Specific examples of such an onium salt compound include a sulfonium salt compound represented by the following formula (13-1) and an iodonium salt compound represented by the following formula (13-2).

R ^{21 to} R ²⁵ in the above formulas (13-1) and (13-2) each independently represent a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom.
Z ⁻ represents OH ⁻ , R—COO ⁻ , R—SO ₃ ⁻ (wherein R represents an alkyl group, an aryl group, or an alkanol group) or an anion represented by the following formula (14). .

  Specific examples of the sulfonium salt compound and the iodonium salt compound include triphenylsulfonium hydroxide, triphenylsulfonium acetate, triphenylsulfonium salicylate, diphenyl-4-hydroxyphenylsulfonium hydroxide, diphenyl-4-hydroxyphenylsulfonium acetate. Diphenyl-4-hydroxyphenylsulfonium salicylate, 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- Tylphenyl-4-hydroxyphenyliodonium hydroxide, 4-t-butylphenyl-4-hydroxyphenyliodonium acetate, 4-t-butylphenyl-4-hydroxyphenyliodonium salicylate, bis (4-t-butylphenyl) iodonium Examples thereof include 10-camphor sulfonate, diphenyliodonium 10-camphor sulfonate, triphenylsulfonium 10-camphor sulfonate, and 4-t-butoxyphenyl diphenylsulfonium 10-camphor sulfonate.

Examples of the nitrogen-containing heterocyclic compound include pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine. , Nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine and other pyridines; piperazine, piperazines such as 1- (2-hydroxyethyl) piperazine, pyrazine, pyrazole, 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-methylimidazole, 1 Benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, and 2-phenylbenzimidazole, and the like.
Such nitrogen-containing compounds (C) can be used alone or in admixture of two or more.

  In the radiation-sensitive resin composition of the present invention, the content ratio of the nitrogen-containing compound (C) is less than 10 parts by mass with respect to 100 parts by mass of the resin (A) from the viewpoint of ensuring high sensitivity as a resist. Preferably, the amount is less than 5 parts by weight, more preferably less than 3 parts by weight. In addition, although the minimum of the usage-amount of a nitrogen-containing compound is not specifically limited, Usually, it is 0.001 mass part or more. When the amount of the nitrogen-containing compound used exceeds 10 parts by mass, the sensitivity as a resist may be remarkably lowered. On the other hand, if the amount of the nitrogen-containing compound used is less than 0.001 part by mass, the pattern shape and dimensional fidelity as a resist may decrease depending on the process conditions.

Additive (D):
In the radiation sensitive resin composition of the present invention, if necessary, a fluorine-containing resin additive (d-1), an alicyclic skeleton-containing additive (d-2), a surfactant (d-3), Various additives (D) such as a sensitizer (d-4) can be blended. The content ratio of each additive can be appropriately determined according to the purpose.

The fluorine-containing resin additive (d-1) exhibits an effect of developing water repellency on the resist film surface, particularly in immersion exposure, and suppresses elution of components from the resist film to the immersion liquid. Even if immersion exposure is performed, the component is effective in suppressing immersion-derived defects such as watermark defects without leaving droplets. The structure of the fluorine-containing resin additive (d1) is not particularly limited except that it contains one or more fluorine atoms. The fluorine-containing resin additive (1) to (4) shown below ( d-1-1) to (d-1-4).
(1) A fluorine-containing resin additive (d-1-1) that itself is insoluble in a developer and becomes alkali-soluble by the action of an acid.
(2) A fluorine-containing resin additive (d-1-2) which is itself soluble in a developer and whose alkali solubility is increased by the action of an acid.
(3) A fluorine-containing resin additive (d-1-3) that itself is insoluble in the developer and becomes alkali-soluble by the action of alkali.
(4) A fluorine-containing resin additive (d-1-4) which is itself soluble in a developer and whose alkali solubility is increased by the action of alkali.

  The fluorine-containing resin additive (d-1) having any one of the properties (1) to (4) has at least one of the other repeating unit (a-5) and the fluorine-containing repeating unit. Has at least one repeating unit selected from repeating units (a-1), (a-2), and other repeating units.

  Specific examples of the monomer constituting the fluorine-containing repeating unit include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) acrylate, and perfluoro. n-propyl (meth) acrylate, perfluoro i-propyl (meth) acrylate, perfluoro n-butyl (meth) acrylate, perfluoro i-butyl (meth) acrylate, perfluoro t-butyl (meth) acrylate, perfluoro Cyclohexyl (meth) acrylate, 2- (1,1,1,3,3,3-hexafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octa Fluoro) pentyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-o Tafluoro) hexyl (meth) acrylate, perfluorocyclohexylmethyl (meth) acrylate, 1- (2,2,3,3,3-pentafluoro) propyl (meth) acrylate, 1- (2,2,3,3, 4,4,4-heptafluoro) penta (meth) acrylate, 1- (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10, And 10-heptadecafluoro) decyl (meth) acrylate, 1- (5-trifluoromethyl-3,3,4,4,5,6,6,6-octafluoro) hexyl (meth) acrylate, and the like. it can.

Examples of the fluorine-containing resin additive (d-1) include repeating units represented by the following formulas (15-1) to (15-6). In the following formulas (15-1) to (15-6), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

The alicyclic skeleton-containing additive (d-2) as the additive (D) is a component that exhibits an action of further improving dry etching resistance, pattern shape, adhesion to the substrate, and the like.
Examples of such alicyclic skeleton-containing additive (d-2) include 1-adamantanecarboxylic acid, 2-adamantanone, 1-adamantanecarboxylate t-butyl, and 1-adamantanecarboxylate t-butoxycarbonylmethyl. 1-adamantanecarboxylic acid α-butyrolactone ester, 1,3-adamantane dicarboxylate di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantaneacetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di Adamantane derivatives such as t-butyl, 2,5-dimethyl-2,5-di (adamantylcarbonyloxy) hexane;
Deoxycholate t-butyl, deoxycholate t-butoxycarbonylmethyl, deoxycholate 2-ethoxyethyl, deoxycholate 2-cyclohexyloxyethyl, deoxycholate 3-oxocyclohexyl, deoxycholate tetrahydropyranyl, deoxychol Deoxycholic acid esters such as acid mevalonolactone ester; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, 2-cyclohexyloxyethyl lithocholic acid, 3-oxocyclohexyl lithocholic acid, lithol Lithocholic acid esters such as tetrahydropyranyl acid, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-adipate Chill, alkyl carboxylic acid esters such as adipate t- butyl;
3- [2-Hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, 2-hydroxy-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nonane, and the like. These alicyclic skeleton containing additives (d-2) can be used individually or in mixture of 2 or more types.
The surfactant (d-3) as the additive (D) is a component having an action of improving coatability, striation, developability and the like.
Examples of such surfactant (d-3) include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl. In addition to nonionic surfactants such as ether, polyethylene glycol dilaurate, polyethylene glycol distearate, etc., 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), Florard FC430, FC431 (Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (made by Asahi Glass Co., Ltd.), etc. Can do. These surfactants can be used alone or in admixture of two or more.

The sensitizer (d-4) as the additive (D) absorbs radiation energy and transmits the energy to the acid generator (B), thereby increasing the amount of acid generated. It has the effect of improving the apparent sensitivity of the radiation-sensitive resin composition.
Examples of such a sensitizer (d-4) include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. . These sensitizers (d3) can be used alone or in admixture of two or more.
Furthermore, as the additive (D), at least one selected from the group consisting of dyes, pigments, and adhesion assistants can also be used. For example, by using a dye or a pigment as the additive (D), the latent image in the exposed area can be visualized, and the influence of halation during exposure can be reduced. Moreover, adhesiveness with a board | substrate can be improved by using an adhesion assistant as an additive (D). Furthermore, examples of additives other than the above include alkali-soluble resins, low-molecular alkali solubility control agents having an acid-dissociable protecting group, antihalation agents, storage stabilizers, antifoaming agents, and the like.

The content of the additive (D) is preferably less than 50 parts by weight, more preferably less than 25 parts by weight, and particularly preferably less than 15 parts by weight with respect to 100 parts by weight of the resin (A).
In addition, as for an additive (D), each additive demonstrated so far may be used independently as needed, and may be used in combination of 2 or more types.

Solvent (E):
The solvent (E) is not particularly limited as long as the solvent can dissolve the resin (A) and the radiation-sensitive acid generator (B). In addition, when a radiation sensitive resin composition further contains a nitrogen-containing compound (C) and an additive (D), it is preferable that it is a solvent which also melt | dissolves these components.
Examples of the solvent (E) include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-i-propyl ether acetate, propylene glycol mono-n-butyl ether acetate. Propylene glycol monoalkyl ether acetates such as propylene glycol mono-i-butyl ether acetate, propylene glycol mono-sec-butyl ether acetate, propylene glycol mono-t-butyl ether acetate; cyclopentanone, 3-methylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, isophorone, etc. Cyclic ketones; 2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone, 4-methyl-2-pentanone, 3-methyl-2-pentanone, 3,3-dimethyl-2-butanone Linear or branched ketones such as 2-heptanone and 2-octanone; methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, n-propyl 2-hydroxypropionate, i-hydroxy-2-hydroxypropionate Alkyl 2-hydroxypropionates such as propyl, n-butyl 2-hydroxypropionate, i-butyl 2-hydroxypropionate, sec-butyl 2-hydroxypropionate, t-butyl 2-hydroxypropionate; 3-methoxy Methyl propionate, ethyl 3-methoxypropionate, 3-ethoxypropyl Methyl acid, ethyl 3-ethoxypropionate and the like of 3-alkoxy propionic acid alkyl ethers other,

n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether , Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, propylene glycol monomethyl ether , Propylene glycol monoethyl Ether, propylene glycol mono-n-propyl ether, toluene, xylene, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl acetoacetate, Ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, benzyl ethyl ether, di-n-hexyl ether, diethylene glycol monomethyl ether, diethylene glycol Cole monoethyl ether, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, etc. Can do.
Among these, it is preferable to contain propylene glycol monoalkyl ether acetates, particularly propylene glycol monomethyl ether acetate. Furthermore, cyclic ketones, linear or branched ketones, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, γ-butyrolactone and the like are preferable. These solvents can be used alone or in admixture of two or more.

Photoresist pattern formation method:
The radiation sensitive resin composition of the present invention is useful as a chemically amplified resist. By exposing the radiation-sensitive resin composition to radiation and the like, an acid is generated from the contained radiation-sensitive acid generator (B), and the reaction using the generated acid as a catalyst results in a resin (A) component. The acid dissociable group in the inside is dissociated to form a carboxyl group, and as a result, the solubility of the exposed portion in the alkaline developer is increased. Therefore, only the exposed portion is easily dissolved and removed by the alkali developer, and a positive photoresist pattern can be formed.
The photoresist pattern can be formed, for example, as follows. A step of forming a photoresist film on the substrate using the radiation-sensitive resin composition (hereinafter referred to as “step (1)”), and the formed photoresist film may be subjected to an immersion medium in some cases. Then, a step of irradiating and exposing to radiation through a mask having a predetermined pattern (hereinafter referred to as “step (2)”), a step of developing the exposed photoresist film and forming a photoresist pattern (hereinafter referred to as “step (2)”). , "Step (3)").

In step (1), a solution obtained by dissolving the radiation-sensitive resin composition of the present invention in a solvent is applied onto a substrate by an appropriate application means such as spin coating, cast coating, roll coating, or the like. To form a photoresist film. More specifically, after applying the solution so that the photoresist film to be formed has a predetermined thickness, the solvent in the coating film is volatilized by pre-baking (PB) to form a photoresist film. Can do. Examples of the substrate include a silicon wafer and a wafer coated with silicon dioxide.
The film thickness of the photoresist film is not particularly limited, but is usually 0.05 to 5 μm, preferably 0.05 to 3 μm, and more preferably 0.05 to 1 μm. Moreover, although the prebaking heating conditions change with the compounding composition of a radiation sensitive resin composition, it is 30-200 degreeC normally, It is preferable that it is 50-150 degreeC, It is still more preferable that it is 70-130 degreeC. .
In order to maximize the potential of the radiation-sensitive resin composition, as disclosed in, for example, Japanese Patent Publication No. 6-12452 (Japanese Patent Laid-Open No. 59-93448), etc. It is also possible to form an organic or inorganic antireflection film. In order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film can be provided on the photoresist film as disclosed in, for example, Japanese Patent Laid-Open No. 5-188598. Furthermore, a liquid immersion protective film may be provided on the photoresist film. These techniques can be used in combination.

Step (2) is a step of exposing the photoresist film formed in step (1) by irradiating with radiation through an immersion medium such as water as the case may be. In addition, when irradiating a radiation, a radiation is irradiated through the mask which has a predetermined pattern.
Here, when performing immersion exposure, in order to protect the direct contact between the immersion liquid and the resist film as necessary, an immersion-insoluble immersion protective film is provided before the step (2). It is preferably provided on the resist film. As the immersion protective film, for example, disclosed in JP-A-2006-227632, etc., a solvent-peeled immersion protective film that is peeled off by a solvent before step (3), or WO 2005-069076 There is a developer peeling type immersion protective film that is peeled off at the same time as the development in the step (3), which is disclosed in WO2006-035790. The immersion protective film is not particularly limited, but it is more preferable to use a developer peeling type immersion protective film in consideration of throughput and the like.
Examples of radiation include visible light, ultraviolet light, far ultraviolet light, X-rays, and charged particle beams, depending on the type of radiation-sensitive acid generator used. Among these, it is preferable to use far ultraviolet rays. As a source of deep ultraviolet light, there is an ArF excimer laser (wavelength 193 nm) or a KrF excimer laser (wavelength 248 nm), and it is preferable to use an ArF excimer laser (wavelength 193 nm) as a source of deep ultraviolet light.
The exposure conditions such as the exposure amount are appropriately selected according to the blending composition of the radiation-sensitive resin composition, the type of additive, and the like. Further, it is preferable to perform a heat treatment (PEB) after the exposure. By PEB, the dissociation reaction of the acid dissociable group contained in the resin (A) proceeds smoothly. The heating conditions for PEB vary depending on the composition of the radiation sensitive resin composition, but are usually 30 to 200 ° C, preferably 50 to 170 ° C, and more preferably 70 to 150 ° C.

Step (3) is a step of forming a predetermined photoresist pattern by developing the exposed photoresist film. Specific examples of the developer used for this development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propyl. Amine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo -[4.3.0] -5-Alkaline aqueous solution in which an alkaline compound such as nonene is dissolved in water. The concentration of the alkaline aqueous solution is usually 10% by mass or less. When the concentration of the alkaline aqueous solution is more than 10% by mass, the unexposed area may be dissolved in the developer. In addition, after developing the exposed photoresist film with a developing solution, generally it wash | cleans with water and dries.
An appropriate amount of an organic solvent, a surfactant, or the like can be added to the developer. Examples of the organic solvent include acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, 2,6-dimethylcyclohexanone, and the like; methyl alcohol, ethyl alcohol, n-propyl alcohol, alcohols such as i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol and 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane; acetic acid Examples include esters such as ethyl, n-butyl acetate, and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; and phenol, acetonylacetone, dimethylformamide, and the like. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.
[Mw, Mn, and Mw / Mn]:
Tosoh GPC columns (trade name “G2000HXL”, product name “G3000HXL”, product name “G4000HXL”) are used, flow rate: 1.0 ml / min, elution solvent: tetrahydrofuran, column Temperature: Measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under analysis conditions of 40 ° C. Further, the degree of dispersion “Mw / Mn” was calculated from the measurement results of Mw and Mn.
[ ¹³ C-NMR analysis]:
The ¹³ C-NMR analysis of each polymer was measured using a trade name “JNM-EX270” manufactured by JEOL Ltd.
[Content of low molecular weight component (% by mass)]:
High-performance liquid chromatography using a trade name “Intersil ODS-25 μm column” (4.6 mmφ × 250 mm) manufactured by GL Sciences Inc. under analysis conditions of a flow rate of 1.0 mL / min and an elution solvent acrylonitrile / 0.1% phosphoric acid aqueous solution. (HPLC). The low molecular weight component is a component having a monomer as a main component, and more specifically, a component having a molecular weight of 500 or less.

[Sensitivity (mJ / cm ² )]:
When a positive resist pattern was formed, the exposure amount for forming a line-and-space pattern (1L1S) having a line width of 90 nm with a one-to-one line width was defined as the optimum exposure amount, and this optimum exposure amount was defined as sensitivity. For this measurement, a scanning electron microscope (trade name “S-9380”, manufactured by Hitachi High-Technologies Corporation) was used.
[Resolution (nm)]:
The minimum resist pattern dimension that can be resolved at the optimum exposure dose is defined as the resolution.
[Evaluation method of pattern cross-sectional shape]:
The cross-sectional shape of the line-and-space pattern with a line width of 90 nm was observed with the trade name “S-4800” (manufactured by Hitachi High-Technologies Corporation), the line width Lb in the middle of the resist pattern, and the upper part of the film The line width La was measured, and the case where it was within the range of 0.9 ≦ (La−Lb) /Lb≦1.1 was evaluated as “good”, and the case where it was out of the range was evaluated as “bad”.
[Evaluation method of PEB temperature dependency]:
Observation of a line-and-space pattern with a line width of 90 nm resolved at the optimum exposure dose, and observed from above the pattern with a scanning electron microscope (trade name “S-9380”, manufactured by Hitachi High-Technologies Corporation) The difference between the line width when PEB is performed and the line width at the optimum exposure when PEB is changed by ± 2 ° C. and the amount of change when divided by the temperature difference It was defined as PEB temperature dependency (nm / ° C.), and the case where the PEB temperature dependency was less than 3 nm / ° C. was evaluated as “good”, and the case where it was 3 nm / ° C. or higher was evaluated as “bad”.

[LWR (nm)]:
In observing a line-and-space pattern with a line width of 90 nm resolved at the optimum exposure dose, the pattern is observed from above the pattern with a scanning electron microscope (trade name “S-9380”, manufactured by Hitachi High-Technologies Corporation). At that time, the line width was observed at an arbitrary point, and the measurement variation was evaluated by 3σ.
[Minimum dimension before collapse (nm)]:
When observing a line-and-space pattern with a line width of 90 nm resolved at an optimal exposure amount, the scanning electron microscope (trade name “S-9380”, manufactured by Hitachi High-Technologies Corporation) is used to observe from above the pattern. The line width at the maximum exposure amount at which no collapse of the resist pattern was confirmed was defined as the minimum dimension before collapse.
[Blob defect evaluation method]:
The substrate for blob defect evaluation was measured under the trade name “KLA2351” (manufactured by KLA Tencor). When the number of detected blob defects was 200 or less, it was evaluated as “good”. It was evaluated as “bad”.

Synthesis of resin (A):
Resin (A) was synthesized using compounds (M-1) to (M-7) shown in Table 1 in each synthesis example. Compounds (M-1) to (M-7) are represented by the following formulas (M-1) to (M-7).

Synthesis Example 1: Resin (A-1)
30.46 g (50 mol%) of the above compound (M-1) and 19.54 g (50 mol%) of the above compound (M-2) are dissolved in 100 g of 2-butanone, and further, azobisisobutyro is used as an initiator. A monomer solution charged with 1.91 g (5 mol%) of nitrile (AIBN) was prepared.
Next, 50 g of 2-butanone was charged into a 500 ml three-necked flask equipped with a thermometer and a dropping funnel, and the inside of this three-necked flask was purged with nitrogen for 30 minutes. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. while stirring with a magnetic stirrer, and the monomer solution prepared in advance was maintained for 3 hours using a dropping funnel while maintaining the temperature. It was dripped over. The polymerization reaction was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling. After cooling, it was poured into 1000 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 200 g of methanol as a slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder copolymer (36 g, yield 72%). . This copolymer is referred to as “resin (A-1)”.

This copolymer has Mw of 6930, Mw / Mn of 1.61, and as a result of ¹³ C-NMR analysis, each of the repeating units derived from the compound (M-1) and the compound (M-2) The content rate was 50.9: 49.1 (mol%). Moreover, content of the low molecular weight component in this copolymer was 0.04 mass%. The measurement results are shown in Table 2.

Synthesis Examples 2 to 7: Resins (A-2) to (A-7)
Resins (A-2) to (A-7) were synthesized in the same manner as in Synthesis Example 1 except that the formulation shown in Table 1 was used. In Table 1, MAIB is dimethyl-2,2'-azobis (isobutyrate).
Moreover, about the obtained resin (A-1)-(A-7), the ratio (mol%) of each repeating unit by ¹³ C-NMR analysis, a yield (%), Mw, dispersity (Mw / Mn) ) And the measurement results of the residual ratio (mass%) of the low molecular weight component are shown in Table 2.

As a reference example substrate, a 12-inch silicon wafer having a 77 nm-thick lower layer antireflection film (trade name “ARC29A”, manufactured by Brewer Science) on the surface was used. This antireflection film was provided using a trade name “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Ltd.). Next, the resin (A-1) obtained in Synthesis Example 1 was spin-coated on a substrate under the trade name “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Ltd.), and then PB was performed, whereby a film thickness of 120 nm was obtained. A photoresist film was formed. The formed photoresist film was exposed through a mask pattern using an ArF excimer laser exposure apparatus (trade name “NSR S306C”, manufactured by Nikon, illumination condition: NA 0.78 sigma 0.93 / 0.69). Then, after performing PEB, it was developed in a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 30 seconds, washed with water, and dried to form a positive resist pattern. The formed positive resist pattern has a sensitivity of 32.5 mJ / cm ² , a resolution of 75 nm, a shape of “good”, a PEB temperature dependency of “good”, and an LWR of 6.1 nm. The minimum collapse size was 47 nm.

  The measurement of the blob defect was performed using an 8-inch silicon wafer subjected to hexamethyldisilazane treatment at 100 ° C. for 60 seconds using a trade name “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Ltd.) as a substrate. And an ArF excimer laser exposure apparatus (“NSR S306C”, manufactured by Nikon, illumination condition: NA 0.78 sigma 0.85) and exposed at an optimum exposure amount through a rubbed glass on which no mask pattern is formed. Except for the above, a positive resist pattern was formed in the same manner as described above. The blob defect of the formed positive resist pattern was “good”.

Examples 1-4 , Comparative Examples 1-2
For Examples 1 to 4 and Comparative Examples 1 to 2, positive resist patterns were formed in the same manner as in the Reference Example except that the conditions were as shown in Table 3. Each positive resist pattern formed was measured and evaluated for sensitivity, resolution, shape, PEB temperature dependency, LWR, minimum collapse dimension, and blob defect. The results are shown in Table 4. In addition, about components other than resin of the radiation sensitive resin composition shown in Table 3, it shows below.

(B) Acid generator (B-1): 4-cyclohexylphenyl diphenylsulfonium nonafluoro-n-butanesulfonate (B-2): triphenylsulfonium nonafluoro-n-butanesulfonate (B-3): 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate (B-4): 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2- (Bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate (B-5): triphenylsulfonium · 2- (bicyclo [2.2.1] hepta -2-yl) -1,1,2,2-tetrafluoroethanesulfonate (B-6): triphenylsulfonium 2- ( Cyclo [2.2.1] hept-2-yl) -1,1-difluoroethanesulfonate (C) Nitrogen-containing compound (C-1): Nt-butoxycarbonyl-4-hydroxypiperidine (C-2): R-(+)-(tert-butoxycarbonyl) -2-piperidinemethanol (C-3): Nt-butoxycarbonylpyrrolidine (C-4): Nt-butoxycarbonyl-2-phenylbenzimidazole (C -5): Triethanolamine (D) additive (D-1): t-butoxycarbonylmethyl lithocholic acid (E) solvent (E-1): propylene glycol monomethyl ether acetate (E-2): cyclohexanone (E- 3): γ-butyrolactone

  From the results shown in Table 4, not only resolution but also sensitivity, shape, PEB temperature dependency, LWR, minimum collapse size, and blob defect resist performance can be improved by using the radiation-sensitive resin composition of the present invention. I understood.

  The radiation-sensitive composition of the present invention is used notably for lithography processes using an ArF excimer laser as a light source, and not only has excellent resolution performance in the formation of fine patterns of 90 nm or less and also in immersion exposure processes. , LWR is small, PEB temperature dependency is good, pattern collapse characteristics are excellent, and it can be used as a chemically amplified resist having excellent defect performance.

Claims (2)

A resin (A) containing a repeating unit (a-1) represented by the following formula (1) and a repeating unit (a-2) having an acid dissociable group;
It is selected from the radiation sensitive acid generator (b-1) containing the compound represented by the following formula (2) and the radiation sensitive acid generator (b-2) containing the compound represented by the formula (2 ′). A radiation-sensitive resin composition containing at least one radiation-sensitive acid generator (B).

In (Equation (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkylene group or an alicyclic alkylene group having 1 to 12 carbon atoms, m represents an integer of 1 to 3,
In Formula (2), R ³ is a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or a carbon number 2 to 11 linear or branched alkoxycarbonyl groups,
In the formula (2 ′), R ^{3 ′} is a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a linear or branched alkoxyl group having 1 to 10 carbon atoms. Or a linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms,
In Formula (2) and Formula (2 ′), R ⁴ is a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or carbon Represents a linear, branched or cyclic alkanesulfonyl group having 2 to 11 carbon atoms, and R ⁵ is independently a linear or branched alkyl group having 1 to 10 carbon atoms and optionally substituted phenyl. Group or naphthyl group, or two R ⁵ 's bonded to each other to form a divalent group having 2 to 10 carbon atoms, the divalent group may be substituted, and k is 0 to Is an integer of 2, r is an integer of 0 to 10,
X ⁻ is an anion of the following formula (3), and two R ⁵ in the formula (2) and the formula (2 ′) are not bonded to each other to form a divalent group having 2 to 10 carbon atoms. ,

In Formula (3), when it becomes an anion of Formula (2), R ⁶ represents a hydrogen atom, a fluorine atom, or a hydrocarbon group having 1 to 12 carbon atoms, and n is 1 to 10 When it is an integer and becomes an anion of the formula (2 ′), R ⁶ represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and n is an integer of 1 to 10. ) In the formula (1), the alkylene group or alicyclic alkylene group having 1 to 12 carbon atoms represented by R ² is a linear alkylene group having 1 to 12 carbon atoms or a branched chain having 2 to 12 carbon atoms. The radiation-sensitive resin composition according to claim 1, which is an alkylene group or a cycloalkylene group.