JP5176909B2 - Polymer and radiation-sensitive resin composition - Google Patents

Description

  The present invention relates to a radiation-sensitive resin composition used in a semiconductor manufacturing process such as IC, a circuit board such as a liquid crystal or a thermal head, and other photolithography processes, and used as a resin component in this radiation-sensitive resin composition. It relates to a polymer that can be produced. More specifically, the present invention relates to a chemically amplified radiation-sensitive resin composition that can be suitably used in a photolithography process using an ultraviolet ray or an electron beam having a wavelength of 220 nm or less, such as an ArF excimer laser, as an exposure light source.

The chemically amplified radiation-sensitive resin composition generates an acid in an exposed portion by irradiation with far ultraviolet rays or electron beams typified by a KrF excimer laser or an ArF excimer laser, and is exposed by a chemical reaction using this acid as a catalyst. It is a composition that causes a difference in the dissolution rate of the part and the unexposed part in the developer to form a resist pattern on the substrate.
For example, when a KrF excimer laser (wavelength 248 nm) is used as a light source, a polymer having a basic skeleton of poly (hydroxystyrene) (hereinafter referred to as “PHS”), which has a small absorption in the 248 nm region, is a constituent component. A chemically amplified radiation sensitive resin composition is used. According to this composition, high sensitivity, high resolution, and good pattern formation can be realized.
However, when a shorter wavelength light source, for example, an ArF excimer laser (wavelength 193 nm) is used as a light source for the purpose of further microfabrication, an aromatic compound such as PHS having a large absorption in the 193 nm region should be used. There was a problem that was difficult.
Therefore, as a lithography material using an ArF excimer laser as a light source, a polymer having an alicyclic hydrocarbon having no large absorption in the 193 nm region in its skeleton, particularly a polymer having a lactone skeleton in its repeating unit is constituted. A resin composition as a component is used.

  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).

  It has been found that the above-mentioned composition has a lactone skeleton in its repeating unit, so that the resolution performance as a resist is remarkably improved. However, at the present time when the miniaturization of resist patterns has progressed to a level of 90 nm or less, not only high resolution performance but also other performance has been required. For example, as one of the resist pattern miniaturization techniques, liquid immersion exposure is currently being put into practical use, and a resist material that can cope with this liquid immersion exposure is demanded. Specifically, low line width roughness (hereinafter sometimes referred to as “LWR”), low defectivity, low post-exposure bake (hereinafter referred to as “PEB”). ) Development of materials that satisfy various required characteristics such as temperature dependence and pattern collapse resistance is required.

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 problems, and not only has excellent resolution performance, but also has low LWR, excellent pattern collapse resistance, and low defectivity, that is, excellent defectivity. The object is to provide a radiation-sensitive resin composition useful as a chemically amplified resist and a polymer that can be used as a resin component in the radiation-sensitive resin composition.

  As a result of intensive studies, the present inventors use a polymer containing two types of repeating units represented by a specific chemical formula and a repeating unit having an acid-dissociable group as the resin of the radiation-sensitive resin composition. Thus, the present inventors have found that the above problem can be solved, and have completed the present invention. That is, the polymer of the present invention has a repeating unit (a-1) represented by the following formula (1), a repeating unit (a-2) represented by the following formula (2), and an acid dissociable group. And repeating unit (a-3).

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は水素原子、メチル基、またはトリフルオロメチル基を表し、Ｒ⁴は２価の炭素数３〜９の脂環式炭化水素基、メチレン基、または炭素数２〜９の直鎖状もしくは分岐状のアルキレン基を表す。

In the 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, and the formula (2 R ³ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁴ represents a divalent alicyclic hydrocarbon group having 3 to 9 carbon atoms, a methylene group, or a straight chain having 2 to 9 carbon atoms. Represents a chain or branched alkylene group.

  The radiation-sensitive resin composition of the present invention is a radiation-sensitive resin composition containing, as a resin (A), a resin containing the above polymer, and the resin containing a radiation-sensitive acid generator (B). It is characterized by.

  Since the radiation sensitive resin composition of the present invention uses a resin containing a polymer containing the repeating unit (a-1), the repeating unit (a-2) and the repeating unit (a-3) as the resin (A), It can be suitably used as a chemically amplified resist having not only excellent resolution performance but also low LWR, excellent pattern collapse resistance, and low defects, that is, excellent defects. In particular, the radiation-sensitive resin composition of the present invention is used in a lithography process using an ArF excimer laser as a light source. The various performances as can be shown.

  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 contains a resin (A) and a radiation-sensitive acid generator (B), and depending on the purpose, a nitrogen-containing compound (hereinafter 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)”), and the like. Hereinafter, each component will be described.

Resin (A):
Resin (A) includes a repeating unit (a-1) represented by the above formula (1), a repeating unit (a-2) represented by the above formula (2), and a repeating unit having an acid dissociable group ( It is resin containing the polymer containing a-3).
[Repeating unit (a-1)]
The repeating unit (a-1) is a repeating unit represented by the above formula (1) and having a lactone skeleton derived from norbornanecarboxylic acid, and is an essential unit of the polymer of the present invention.
R ¹ in formula (1) is preferably a methyl group.
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.

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.

[Repeating unit (a-2)]
The repeating unit (a-2) is represented by the above formula (2).
As a bivalent C3-C9 alicyclic hydrocarbon group which shows R < ⁴ > in Formula (2), For example, cyclobutylene groups, such as a 1, 3- cyclobutylene group, 1, 3- cyclopentylene group Monocyclic such as a cyclopentylene group such as 1,4-cyclohexylene group, a cyclohexylene group such as 1,4-cyclohexylene group, and a cycloalkylene group having 3 to 9 carbon atoms such as a cyclooctylene group such as 1,5-cyclooctylene group Hydrocarbon ring group, 1-bicyclo [2.2.1] pent-4-methylene group, 1-bicyclo [2.2.2] oct-4-methylene group, 1,3-tetracyclo [3.3.1] ^1,5 . 1 ^3,7] can be mentioned N-cyclic hydrocarbon ring groups such as decylene.
Examples of the linear or branched alkylene group having 2 to 9 carbon atoms include a propylene group such as an ethylene group, a 1,3-propylene group or a 1,2-propylene group, a 1,4-butylene group, or 1, A butylene group such as a 3-butylene group and a 1,8-octylene group can be exemplified.

好ましい単量体としては、（メタ）アクリル酸（１，１，１−トリフルオロ−２−トリフルオロメチル−２−ヒドロキシ−３−プロピル）エステル、（メタ）アクリル酸（１，１，１−トリフルオロ−２−トリフルオロメチル−２−ヒドロキシ−４−ブチル）エステル、（メタ）アクリル酸（１，１，１−トリフルオロ−２−トリフルオロメチル−２−ヒドロキシ−５−ペンチル）エステル、（メタ）アクリル酸（１，１，１−トリフルオロ−２−トリフルオロメチル−２−ヒドロキシ−４−ペンチル）エステル、（メタ）アクリル酸２−｛［５−（１’，１’，１’−トリフルオロ−２'−トリフルオロメチル−２'−ヒドロキシ）プロピル］ビシクロ［２．２．１］ヘプチル｝エステル、（メタ）アクリル酸３−｛［８−（１’，１’，１’−トリフルオロ−２’−トリフルオロメチル−２’−ヒドロキシ）プロピル］テトラシクロ［６．２．１．１^3,6．０^2,7］ドデシル｝エステル等を挙げることができる。
本発明の重合体は、これら例示された単量体より得られる２種類以上の繰り返し単位（ａ−２）を含んでいてもよい。 Preferable monomers that give such a repeating unit (a-2) include the following formula (2-1). In the following formula (2-1), R ³ and R ⁴ are the same as those in the formula (2).

Preferred monomers include (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-3-propyl) ester, (meth) acrylic acid (1,1,1- (Trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-5-pentyl) ester, (Meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester, (meth) acrylic acid 2-{[5- (1 ′, 1 ′, 1 '-Trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl] bicyclo [2.2.1] heptyl} ester, (meth) acrylic acid 3-{[8- (1', 1 ', 1 '-Tori Ruoro-2'-trifluoromethyl-2'-hydroxy) propyl] tetracyclo [6.2.1.1 ^{3, 6.} 0 ^2,7 ] dodecyl} ester and the like.
The polymer of the present invention may contain two or more kinds of repeating units (a-2) obtained from these exemplified monomers.

Moreover, the polymer of this invention contains the repeating unit (a-3) which has an acid dissociable group. The acid dissociable group is, for example, a group obtained by substituting a hydrogen atom in an acidic functional group such as a phenolic hydroxyl group, a carboxyl group, or a sulfonic acid group, and means a group that dissociates in the presence of an acid.
As long as the repeating unit (a-3) has a group (acid dissociable group) that dissociates in the presence of an acid as described above, it can be used, for example, in a known radiation-sensitive resin composition. Although the same repeating unit having an acid dissociable group can be used, in the polymer of the present invention, the repeating unit (a-3) having an acid dissociable group is represented by the following formula (3-1): It is preferable that it is a repeating unit represented by any one of-(3-3).

式（３−１）〜（３−３）において、Ｒ⁵は互い独立して、水素原子、メチル基、または、トリフルオロメチル基を表す。また、式（３−１）および式（３−３）において、Ｒ⁶は互い独立して、炭素数１〜４の直鎖状または分岐状のアルキル基を表し、式（３−２）において、Ｒ⁷は相互に独立して、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（３−３）において、ｇは１〜３の整数を表す。

In formulas (3-1) to (3-3), R ⁵ each independently represents a hydrogen atom, a methyl group, or a trifluoromethyl group. In the formula (3-1) and the formula (3-3), R ⁶ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms, and in the formula (3-2) And R ⁷ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms. Moreover, in Formula (3-3), g represents the integer of 1-3.

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms of R ⁶ and R ^{7 in} the above formulas (3-1) to (3-3) include, for example, a methyl group, an ethyl group, a propyl group, An isopropyl group, an isobutyl group, a t-butyl group, etc. can be mentioned.
Among the monomers giving this repeating unit (a-3), (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid 2-ethyladamantyl-2-yl ester are preferable. , (Meth) acrylic acid 2-ethyl-3-hydroxyadamantyl-2-yl ester, (meth) acrylic acid 2-n-propyladamantyl-2-yl ester, (meth) acrylic acid 2-isopropyladamantyl-2-yl Ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-ethylethyl ester, (meth) acrylic acid 1 -(Adamantan-1-yl) -1-methylpropyl ester, (meth) acrylic acid 1- (adamantane-1 Yl) -1-ethylpropyl ester, (meth) acrylic acid 1-methyl-1-cyclopentyl ester, (meth) acrylic acid 1-ethyl-1-cyclopentyl ester, (meth) acrylic acid 1-isopropyl-1-cyclopentyl ester (Meth) acrylic acid 1-methyl-1-cyclohexyl ester, (meth) acrylic acid 1-ethyl-1-cyclohexyl ester, (meth) acrylic acid 1-isopropyl-1-cyclohexyl ester, (meth) acrylic acid 1- Methyl-1-cycloheptyl ester, (meth) acrylic acid 1-ethyl-1-cycloheptyl ester, (meth) acrylic acid 1-isopropyl-1-cycloheptyl ester, (meth) acrylic acid 1-methyl-1-cyclo Octyl ester, 1-ethyl- (meth) acrylate - cyclooctyl ester, and (meth) acrylic acid 1-isopropyl-1-cyclooctyl ester.
In addition, the polymer may contain two or more types of repeating units (a-3) obtained from these exemplified monomers.

The polymer of the present invention is a resin (A) containing a polymer containing all of the repeating units (a-1), the repeating units (a-2), and the repeating units (a-3) as described above. For example, when it is used as a chemically amplified resist, it not only has excellent resolution performance, but also has low LWR, excellent pattern collapse resistance, and excellent defectability. can do.
Further, this polymer is a repeating unit other than the repeating unit (a-1), the repeating unit (a-2), and the repeating unit (a-3) described above (hereinafter referred to as “other repeating unit”). 1 or more) may be further included.
This other repeating unit is a repeating unit represented by the following formulas (4-1) to (4-6) (hereinafter, these may be referred to as “other repeating units (a-4)”), a formula ( 5) (hereinafter also referred to as “other repeating unit (a-5)”), the repeating unit represented by formula (6) (hereinafter referred to as “other repeating unit (a-6)”. ) ”May be mentioned as a suitable example.
By having at least one type of repeating unit selected from the group consisting of the above repeating units (a-4) to (a-6), the characteristics of the repeating units (a-1) to (a-3) are sufficiently obtained. You can make use of it.

式（４−１）〜（４−６）の各式において、Ｒ⁸は互いに独立して、水素原子、メチル基、トリフルオロメチル基を表し、上記式（４−１）において、Ｒ⁹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、ｌは１〜３の整数を表す。式（４−４）において、Ｒ¹⁰は水素原子、またはメトキシ基を表す。また、式（４−２）および（４−３）において、Ａは単結合またはメチレン基を示し、ｐは０または１を表す。式（４−３）および式（４−５）において、Ｂは酸素原子またはメチレン基を表す。 Other repeating units (a-4) are represented by the following formulas (4-1) to (4-6).

In the formulas (4-1) to (4-6), R ⁸ independently represents a hydrogen atom, a methyl group, or a trifluoromethyl group. In the formula (4-1), R ⁹ represents A hydrogen atom or a C1-C4 alkyl group which may have a substituent is represented, l represents the integer of 1-3. In the formula (4-4), R ¹⁰ represents a hydrogen atom or a methoxy group. In formulas (4-2) and (4-3), A represents a single bond or a methylene group, and p represents 0 or 1. In Formula (4-3) and Formula (4-5), B represents an oxygen atom or a methylene group.

Among the monomers giving another repeating unit (a-4), (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-oxatricyclo [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-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic Acid-2,2-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-2-oxotetrahydrofuran -3-yl ester, (meth) acrylic acid-4,4-dimethyl-2-oxo Trahydrofuran-3-yl ester, (meth) acrylic acid-5,5-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-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.
Moreover, these other repeating units (a-4) can contain 1 type (s) or 2 or more types.

式（５）において、Ｒ¹¹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の多環型シクロアルキル基を表す。この炭素数７〜２０の多環型シクロアルキル基は、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１種で置換されていても、置換されていなくてもよい。 Another repeating unit (a-5) is represented by the following formula (5).

In the formula (5), R ¹¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ¹² represents a polycyclic cycloalkyl group having 7 to 20 carbon atoms. The polycyclic cycloalkyl group having 7 to 20 carbon atoms is at least one 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. It may be substituted with or may not be substituted.

Examples of R ¹² of the other repeating unit (a-5) represented by the formula (5) 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 a cycloalkyl group having a plurality of ring structures such as 0 ^2,7 ] dodecane and tricyclo [3.3.1.1 ^3,7 ] decane.

  Such a cycloalkyl group may have a substituent, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methyl group. You may substitute by 1 or more types or 1 or more of C1-C4 linear, branched or cyclic alkyl groups, such as a propyl group and t-butyl group. 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 A group or an oxygen atom may be substituted. Moreover, these other repeating units (a-5) can contain 1 type (s) or 2 or more types.

Among the monomers that give other repeating units (a-5), (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 . 0 ^2,7 ] dodecanyl ester, (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 ] decanyl ester, and the like.

式（６）において、Ｒ¹³は水素原子またはメチル基を表し、Ｙ¹は単結合または炭素数１〜３の２価の有機基を表し、Ｙ²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、Ｒ¹⁴は互いに独立して、水素原子、水酸基、シアノ基、またはＣＯＯＲ¹⁵基を表す。但し、Ｒ¹⁵は水素原子、炭素数１〜４の直鎖状もしくは分岐状アルキル基、または炭素数３〜２０のシクロアルキル基を表す。
式（６）においては、３つのＲ¹⁴のうち少なくとも１つは水素原子でなく、且つＹ¹が単結合のときは、３つのＹ²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。 Another repeating unit (a-6) is represented by the following formula (6).

In the formula (6), R ¹³ represents a hydrogen atom or a methyl group, Y ¹ represents a single bond or a divalent organic group having 1 to 3 carbon atoms, and Y ² independently of each other represents a single bond or a carbon number. 1 to 3 divalent organic groups, and R ¹⁴ each independently represents a hydrogen atom, a hydroxyl group, a cyano group, or a COOR ¹⁵ group. R ¹⁵ represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms.
In Formula (6), when at least one of the three R ¹⁴ is not a hydrogen atom and Y ¹ is a single bond, at least one of the three Y ² is divalent having 1 to 3 carbon atoms. The organic group is preferably.

Y ¹ and Y ² of the other repeating unit (a-6) represented by the formula (6) represent a single bond or a divalent organic group having 1 to 3 carbon atoms. Examples of the divalent organic group include a methylene group, an ethylene group, and a propylene group.
R ^{15 in the} —COOR ¹⁵ group represented by R ¹⁴ in the other repeating unit (a-6) represented by the formula (6) is a hydrogen atom, a linear or branched alkyl having 1 to 4 carbon atoms. Group, or a cycloalkyl group having 3 to 20 carbon atoms, and the linear or branched alkyl group having 1 to 4 carbon atoms in R ¹⁵ includes a methyl group, an ethyl group, and n-propyl group. Group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group.

Further, the cycloalkyl group having 3 to 20 carbon atoms of the ^{_{R 15, -C n H 2n-}} 1 cycloalkyl group (n is an integer of 3 to 20) represented by the polycyclic alicyclic alkyl group Etc. 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. In the cycloalkyl group and the polycyclic alicyclic alkyl group, a linear, branched or cyclic alkyl group may be substituted as one or more types as a substituent, and there may be a plurality of such substituents. May be. Moreover, these other repeating units (a-6) can contain 1 type (s) or 2 or more types.

  Among the monomers that give other repeating units (a-6), (meth) acrylic acid 3-hydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxyadamantane- 1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-methyladamantan-1-yl ester, (meth) acrylic acid 3,5-dihydroxy-7-methyladamantan-1-yl ester, (meth) acrylic Examples include acid 3-hydroxy-5,7-dimethyladamantan-1-yl ester and (meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-ylmethyl ester.

The polymer contained as the resin (A) in the radiation-sensitive resin composition of the present invention is a repeating unit other than the repeating units (a-1) to (a-6) described above (hereinafter, “further other” It may also be referred to as a “repeat 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, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, cyclopropyl (meth) acrylate, ( (Meth) acrylic acid cyclopentyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid 4-methoxycyclohexyl, (meth) acrylic acid 2-cyclopentyloxycarbonylethyl, (meth) acrylic acid 2-cyclohexyloxycarbonylethyl, (meth) 2- (4-Methoxycyclohexyl) acrylic acid No bridged hydrocarbon skeleton such as aryloxycarbonyl ethyl (meth) acrylate;

α-hydroxymethyl acrylate esters such as methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, n-propyl α-hydroxymethyl acrylate, n-butyl α-hydroxymethyl acrylate; (meth) acrylonitrile , Α-chloroacrylonitrile, crotonnitrile, maleinonitrile, fumaronitrile, mesaconitrile, citraconitrile, itaconnitrile, and other unsaturated nitrile compounds; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, crotonamide, maleinamide , Fumaramide, mesaconamide, citraconic amide, itaconic amide, etc .; N- (meth) acryloylmorpholine, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, vinyl Other nitrogen-containing vinyl compounds such as lysine and vinylimidazole; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, etc. Unsaturated carboxylic acids (anhydrides); 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, Carboxyl group-containing esters having no bridged hydrocarbon skeleton of unsaturated carboxylic acid such as (meth) acrylic acid 4-carboxycyclohexyl;
1,2-adamantanediol di (meth) acrylate, 1,3-adamantanediol di (meth) acrylate, 1,4-adamantanediol di (meth) acrylate, tricyclodecanyl dimethylol di (meth) acrylate, etc. A polyfunctional monomer having a bridged hydrocarbon skeleton;

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

  In the polymer constituting the resin (A), the content of the repeating unit (a-1) is preferably 10 to 85 mol%, and preferably 20 to 80 mol%, based on all repeating units. More preferably, it is 30-70 mol%, and it is especially preferable. By comprising in this way, the developability as a resist, defect property, LWR, PEB temperature dependency, etc. can be improved. For example, in this case, if the content of the repeating unit (a-1) is less than 10 mol%, the developability and defect performance as a resist may deteriorate, and if it exceeds 85 mol%, the resolution as a resist , LWR, PEB temperature dependency may be deteriorated.

  The content of the repeating unit (a-2) is preferably 5 to 30 mol%, more preferably 5 to 20 mol%, and more preferably 10 to 15 mol% with respect to all the repeating units. Is particularly preferred. By comprising in this way, pattern collapse tolerance can be improved.

  The content of the repeating unit (a-3) is preferably 10 to 80 mol%, more preferably 10 to 70 mol%, and more preferably 20 to 70 mol%, based on all repeating units. Is particularly preferred. If the content of the repeating unit (a-3) is less than 10 mol%, the resolution as a resist may be deteriorated. On the other hand, if it exceeds 80 mol%, the developability as a resist may be deteriorated. .

  Further, the other repeating units (a-4) to (a-6) and further other repeating units are optional components, but the content of the other repeating units (a-4) is It is preferably 10 to 70 mol%, more preferably 15 to 65 mol%, particularly preferably 20 to 60 mol%, based on the repeating unit. For example, when the content of the other repeating unit (a-4) exceeds 70 mol%, the solubility in a resist solvent may be lowered, or the resolution may be lowered.

  The content of other repeating units (a-5) is preferably 30 mol% or less, more preferably 25 mol% or less, based on all repeating units. For example, if the content of other repeating units (a-5) exceeds 30 mol%, the resist film may be easily swollen by an alkali developer, or the developability as a resist may be reduced.

The content of other repeating units (a-6) is preferably 30 mol% or less, more preferably 25 mol% or less, based on all repeating units. For example, when the content of other repeating units (a-7) exceeds 30 mol%, the resist film may be easily swollen by an alkali developer, or the developability as a resist may be reduced.
The content of the “further repeating unit” is preferably 50 mol% or less, and more preferably 40 mol% or less, based on all repeating units.

Next, the manufacturing method of a polymer is demonstrated.
The polymer can be synthesized according to a conventional method such as radical polymerization. For example, (1) a method in which a solution containing a monomer and a radical initiator is dropped into a reaction solvent or a solution containing a monomer to cause a polymerization reaction; (2) a solution containing the monomer and a radical A method in which a solution containing an initiator is dropped into a solution containing a reaction solvent or a monomer separately to cause a polymerization reaction; (3) a plurality of types of solutions containing each monomer, and radical initiation It is preferable to synthesize | combine by the method of dripping the solution containing an agent separately to the solution containing a reaction solvent or a monomer, respectively, and carrying out a polymerization reaction.

In addition, when the monomer solution is dropped and reacted with respect to the monomer solution, the monomer amount in the dropped monomer solution is 30 mol with respect to the total amount of monomers used for polymerization. % Or more, more preferably 50 mol% or more, and particularly preferably 70 mol% or more.
What is necessary is just to determine the reaction temperature in these methods suitably with initiator seed | species. Usually, it is 30-180 degreeC, 40-160 degreeC is preferable and 50-140 degreeC is still more preferable. Although dripping time changes with conditions, such as reaction temperature, the kind of initiator, and the monomer made to react, it is 30 minutes-8 hours normally, 45 minutes-6 hours are preferable, and 1-5 hours are still more preferable. Further, the total reaction time including the dropping time varies depending on the conditions as well as the dropping time, but is usually 30 minutes to 8 hours, preferably 45 minutes to 7 hours, and more preferably 1 to 6 hours.

  As radical initiators used for polymerization, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropylpropionitrile), 2,2 '-Azobis (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis ( Cyclohexane-1-carbonitrile), 2,2′-azobis (2-methyl-N-phenylpropionamidine) dihydrochloride, 2,2′-azobis (2-methyl-N-2-propenylpropionamidine) dihydrochloride, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis {2-methyl-N- [1 , 1-bis (hydroxymethyl) 2-hydroxyethyl] propionamide}, dimethyl-2,2′-azobis (2-methylpropionate), 4,4′-azobis (4-cyanovaleric acid), 2, And 2'-azobis (2- (hydroxymethyl) propionitrile). These initiators can be used alone or in admixture of two or more.

As the polymerization solvent, any solvent other than a solvent that inhibits polymerization (nitrobenzene having a polymerization inhibiting effect, mercapto compound having a chain transfer effect, etc.) and capable of dissolving the monomer may be used. it can. Examples thereof include alcohols, ethers, ketones, amides, esters / lactones, nitriles, and mixed solvents thereof.
Examples of alcohols include methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and 1-methoxy-2-propanol.
Examples of ethers include propyl ether, isopropyl ether, butyl methyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, 1,3-dioxane and the like.
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, butyronitrile and the like. These solvents can be used alone or in admixture of two or more.

The polymer obtained by the polymerization reaction is preferably recovered by a reprecipitation method. That is, after completion of the polymerization reaction, the polymer is recovered as a powder by introducing the polymerization solution into a reprecipitation solvent. As a reprecipitation solvent, the solvent illustrated as the said polymerization solvent can be used individually or in mixture of 2 or more types.
The polymer contains a low molecular weight component derived from a monomer, and the content thereof is preferably 0.1% by mass or less with respect to the total amount of the polymer (100% by mass). It is more preferably 0.07% by mass or less, and particularly preferably 0.05% by mass or less.
When the content of this low molecular weight component is 0.1% by mass or less, a resist film is prepared using this polymer as the resin (A), and the resist film is contacted during immersion exposure. The amount of eluate in the water can be reduced. Furthermore, no foreign matter is deposited in the resist during resist storage, and coating unevenness does not occur during resist application. Therefore, it is possible to sufficiently suppress the occurrence of defects when forming a resist pattern.

In the present specification, when the term “low molecular weight component” derived from a monomer is used, the polystyrene-equivalent weight average molecular weight (hereinafter sometimes referred to as “Mw”) by gel permeation chromatography (GPC) is Mw500. It shall mean the following ingredients. Specifically, it is a component such as a monomer, dimer, trimer or oligomer. This low molecular weight component can be removed by, for example, chemical purification methods such as washing with water, liquid-liquid extraction, and the like, and chemical purification methods combined with physical purification methods such as ultrafiltration and centrifugation.
The low molecular weight component can be quantified by analyzing the polymer by high performance liquid chromatography (HPLC). In addition, it is preferable that the polymer has less impurities such as halogen and metal in addition to the low molecular weight component. Thereby, the sensitivity, resolution, process stability, pattern shape and the like can be further improved.

On the other hand, the polystyrene-reduced weight average molecular weight (hereinafter referred to as “Mw”) by gel permeation chromatography (GPC) of the polymer is not particularly limited, but is preferably 1,000 to 100,000, More preferably, it is 000-30,000, and it is especially preferable that it is 1,000-20,000. If the Mw of the polymer is less than 1,000, the heat resistance when used as a resist tends to decrease. On the other hand, when the Mw of the polymer exceeds 100,000, the developability when used as a resist tends to decrease.
Further, the ratio (Mw / Mn) of Mw to the number average molecular weight in terms of polystyrene (hereinafter referred to as “Mn”) by gel permeation chromatography (GPC) of the polymer is usually 1.0 to 5.0. 1.0 to 3.0, and more preferably 1.0 to 2.0.

  In the resin composition of the present invention, the polymer of the present invention can be used alone or in admixture of two or more. Moreover, the polymer of the said invention and the polymer which does not contain a repeating unit (a-1) and a repeating unit (a-2) can be mixed and used. Preferably, the polymer of the present invention is used alone or in combination.

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 to radiation. Acid 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.

式（７）中、Ｒ¹⁶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、Ｒ¹⁷は相互に独立して炭素数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１〜１０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、Ｒ¹⁸は相互に独立して炭素数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、または、置換されていてもよいナフチル基を表す。但し、２個のＲ¹⁸が相互に結合して炭素数２〜１０の２価の基を形成していてもよい。ｋは０〜２の整数であり、ｒは０〜１０の整数である。ｒとしては０〜２が好ましい。 As an acid generator (B), what contains the compound represented by following formula (7) is preferable.

In the formula (7), R ¹⁶ is a hydrogen atom, 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 Represents a linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms, and R ¹⁷ is independently a linear or branched alkyl group having 1 to 10 carbon atoms and a straight chain having 1 to 10 carbon atoms. Represents a linear or branched alkoxyl group or a linear, branched, or cyclic alkanesulfonyl group having 1 to 10 carbon atoms, and R ¹⁸ is independently a linear chain having 1 to 10 carbon atoms. Alternatively, it represents a branched alkyl group, an optionally substituted phenyl group, or an optionally substituted naphthyl group. However, two R ¹⁸ may be bonded to each other to form a divalent group having 2 to 10 carbon atoms. k is an integer of 0 to 2, and r is an integer of 0 to 10. As r, 0-2 are preferable.

式（８−１）および（８−２）中、Ｒ¹⁹は、水素原子、フッ素原子、または、置換されていてもよい炭素数１〜１２の炭化水素基を表し、ｙは１〜１０の整数を表す。
式（８−３）および（８−４）中、Ｒ²⁰は相互に独立して炭素数１〜１０のフッ素置換アルキル基を表す。但し、２個のＲ²⁰が相互に結合して炭素数２〜１０の２価のフッ素置換アルキレン基を形成していてもよい。 X ⁻ represents an anion represented by the following formulas (8-1) to (8-4).

In formulas (8-1) and (8-2), R ¹⁹ represents a hydrogen atom, a fluorine atom, or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, and y is 1 to 10 Represents an integer.
In formulas (8-3) and (8-4), R ²⁰ independently represents a fluorine-substituted alkyl group having 1 to 10 carbon atoms. However, two R ²⁰ may be bonded to each other to form a divalent fluorine-substituted alkylene group having 2 to 10 carbon atoms.

In the formula (7), examples of the linear or branched alkyl group having 1 to 10 carbon atoms represented by R ¹⁶ , R ¹⁷ and R ¹⁸ include a methyl group, an ethyl group, an n-propyl group, i -Propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2 -An ethylhexyl group, n-nonyl group, n-decyl group etc. can be mentioned. Of these alkyl groups, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, and the like are preferable.
Examples of the linear or branched alkoxyl group having 1 to 10 carbon atoms represented by R ¹⁶ and R ¹⁷ include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group. Group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2- Examples thereof include an ethylhexyloxy group, an n-nonyloxy group, and an n-decyloxy group. Of these alkoxyl groups, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, and the like are preferable.
Examples of the linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms represented by R ¹⁶ 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-octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group and the like. Of these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

Examples of the linear, branched, or cyclic alkanesulfonyl group having 1 to 10 carbon atoms represented by R ¹⁷ include a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, and an n-butanesulfonyl group. Group, tert-butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group, n-nonanesulfonyl group, Examples thereof include an n-decanesulfonyl group, a cyclopentanesulfonyl group, and a cyclohexanesulfonyl group. Of these alkanesulfonyl groups, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, and the like are preferable.

In the formula (7), examples of the optionally substituted phenyl group represented by R ¹⁸ include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, and a 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 A phenyl group such as 4-ethylphenyl group, 4-t-butylphenyl group, 4-cyclohexylphenyl group, 4-fluorophenyl group, or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. Substituted phenyl groups; these phenyl groups or alkyl-substituted phenyl groups can be converted into hydroxyl groups, carboxyl groups, cyano groups, nitro groups, alkoxyl groups, alkoxy groups. Kill group, an alkoxycarbonyl group, and the like groups substituted with at least one group in the alkoxycarbonyloxy group.
Among the substituents for the phenyl group and the alkyl-substituted phenyl group, examples of the alkoxyl group include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1- Examples thereof include a linear, branched or cyclic alkoxyl group having 1 to 20 carbon atoms such as a methylpropoxy group, a t-butoxy group, a cyclopentyloxy group, and a cyclohexyloxy group.
Examples of the alkoxyalkyl group include 2 to 21 carbon atoms such as a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, a 1-ethoxyethyl group, and a 2-ethoxyethyl group. And linear, branched or cyclic alkoxyalkyl groups.
Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, an n-butoxycarbonyl group, a 2-methylpropoxycarbonyl group, and a 1-methylpropoxycarbonyl group. , T-butoxycarbonyl group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl and the like, and a linear, branched or cyclic alkoxycarbonyl group having 2 to 21 carbon atoms.
Examples of the alkoxycarbonyloxy group include methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, i-propoxycarbonyloxy group, n-butoxycarbonyloxy group, t-butoxycarbonyloxy group, Examples thereof include linear, branched or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms such as cyclopentyloxycarbonyl group and cyclohexyloxycarbonyl.

Examples of the optionally substituted phenyl group represented by R ¹⁸ in the formula (7) include a phenyl group, a 4-cyclohexylphenyl group, a 4-t-butylphenyl group, a 4-methoxyphenyl group, and a 4-t-butoxyphenyl group. Is preferred.

Examples of the optionally substituted naphthyl group for R ¹⁸ include 1-naphthyl group, 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-naphth 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- A naphthyl group substituted with a naphthyl group such as a methyl-2-naphthyl group, 4-methyl-2-naphthyl group or the like, or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms; these naphthyl groups or Examples include a group in which an alkyl-substituted naphthyl group is substituted with at least one group among a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. Can do.
Examples of the alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group, and alkoxycarbonyloxy group that are the substituents include the groups exemplified for the phenyl group and the alkyl-substituted phenyl group.
In the above formula (7), the optionally substituted naphthyl group of R ¹⁸ is 1-naphthyl group, 1- (4-methoxynaphthyl) group, 1- (4-ethoxynaphthyl) group, 1- (4- n-propoxynaphthyl) group, 1- (4-n-butoxynaphthyl) group, 2- (7-methoxynaphthyl) group, 2- (7-ethoxynaphthyl) group, 2- (7-n-propoxynaphthyl) group , 2- (7-n-butoxynaphthyl) group and the like are preferable.

In addition, the divalent group having 2 to 10 carbon atoms formed by bonding two R ¹⁸ to each other, together with the sulfur atom in the above formula (7), is a 5-membered or 6-membered ring, particularly preferably a 5-membered ring. The group which forms the ring (namely, tetrahydrothiophene ring) is preferable.
Examples of the substituent for the divalent group formed by bonding the two R ¹⁸ to each other include, for example, a hydroxyl group, a carboxyl group, a cyano group exemplified as the substituent for the phenyl group and the alkyl-substituted phenyl group, A nitro group, an alkoxyl group, an alkalkyl group, an alkoxycarbonyl group, an alkoxycarbonyloxy group and the like can be mentioned.
As R ¹⁸ in the formula (7), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, a 1-naphthyl group, and two R ¹⁸ are bonded to each other to form a tetrahydrothiophene ring structure together with a sulfur atom. A divalent group or the like is preferable.

Preferred cation moieties of the above formula (7) include triphenylsulfonium cation, tri-1-naphthylsulfonium cation, tri-tert-butylphenylsulfonium cation, 4-fluorophenyl-diphenylsulfonium cation, di-4-fluorophenyl- Phenylsulfonium cation, tri-4-fluorophenylsulfonium cation, 4-cyclohexylphenyl-diphenylsulfonium cation, 4-methanesulfonylphenyl-diphenylsulfonium cation, 4-cyclohexanesulfonyl-diphenylsulfonium cation, 1-naphthyldimethylsulfonium cation, 1- Naphthyl diethylsulfonium cation,
1- (4-hydroxynaphthyl) dimethylsulfonium cation, 1- (4-methylnaphthyl) dimethylsulfonium cation, 1- (4-methylnaphthyl) diethylsulfonium cation, 1- (4-cyanonaphthyl) dimethylsulfonium cation, 1- (4-cyanonaphthyl) diethylsulfonium cation, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium cation, 1- (4-methoxynaphthyl) tetrahydrothiophenium cation, 1- (4-ethoxy Naphthyl) tetrahydrothiophenium cation, 1- (4-n-propoxynaphthyl) tetrahydrothiophenium cation, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium cation,
2- (7-methoxynaphthyl) tetrahydrothiophenium cation, 2- (7-ethoxynaphthyl) tetrahydrothiophenium cation, 2- (7-n-propoxynaphthyl) tetrahydrothiophenium cation, 2- (7-n -Butoxynaphthyl) tetrahydrothiophenium cation and the like.

Wherein _{(8-1), -C y F 2y} - is a perfluoroalkylene group having y carbon atoms, may be branched may be linear. And y is preferably 1, 2, 4 or 8.

In formulas (8-1) and (8-2) representing the anion moiety, the hydrocarbon group having 1 to 12 carbon atoms represented by R ¹⁹ includes an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, Bridged alicyclic hydrocarbon groups are preferred. 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 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 group Etc.
In formulas (8-3) and (8-4), the fluorine-substituted alkyl group having 1 to 10 carbon atoms represented by R ²⁰ includes a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and nonafluoro. A butyl group, a dodecafluoropentyl group, a perfluorooctyl group, etc. can be mentioned.
Examples of the divalent fluorine-substituted alkylene group having 2 to 10 carbon atoms formed by bonding two R ²⁰ to each other include a tetrafluoroethylene group, a hexafluoropropylene group, an octafluorobutylene group, and a decafluoropentylene group. And undecafluorohexylene group.

As an anion site of the formula (7), trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2- (bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate anion, 2- (bicyclo [2.2.1] hept-2-yl) -1,1-difluoroethanesulfonate anion, 1-adamantylsulfonate anion Anions represented by formulas (8-3a) to (8-3g) are preferred.

  The acid generator (B) is composed of combinations of cations and anions already exemplified. However, the combination is not particularly limited. In this invention, an acid generator (B) may be used individually by 1 type, and 2 or more types may be mixed and used for it.

In the present invention, an acid generator other than the acid generator (B) may be used in combination. Examples of such acid generators include onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, and sulfonic acid compounds. Specifically, the following can be mentioned.
Examples of the onium salt compound include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like. Specific examples of the onium salt compound 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-tetrafluoroethanesulfonate, cyclohexyl, 2-oxocyclohexyl, methylsulfonium trifluoromethane Examples thereof include sulfonate, dicyclohexyl · 2-oxocyclohexylsulfonium trifluoromethanesulfonate, and 2-oxocyclohexyldimethylsulfonium trifluoromethanesulfonate.

Examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound. Specific examples of halogen-containing compounds include (trichloromethyl such as phenylbis (trichloromethyl) -s-triazine, 4-methoxyphenylbis (trichloromethyl) -s-triazine, 1-naphthylbis (trichloromethyl) -s-triazine. ) -S-triazine derivatives; 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane and the like.
Examples of the diazo ketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, a diazonaphthoquinone compound, and the like. Specific examples of the diazo ketone include 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonyl chloride, 1,2, naphthoquinonediazide of 2,3,4,4′-tetrahydroxybenzophenone. -4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester; 1,2-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane Examples include 2-naphthoquinonediazide-5-sulfonic acid ester.
Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds of these compounds. Specific examples of the sulfone compound include 4-trisphenacylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, and the like.

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.
Specific examples of the sulfonic acid compounds include benzoin tosylate, pyrogallol tris (trifluoromethanesulfonate), nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, trifluoromethanesulfonylbicyclo [2.2.1] hept- 5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, perfluoro-n-octanesulfonylbicyclo [2.2 .1] Hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonylbicyclo [2.2. 1] hept-5-ene-2,3-dicarbodiimide,
N- (trifluoromethanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) 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-butanesulfonate, Examples thereof include 1,8-naphthalenedicarboxylic acid imide perfluoro-n-octane sulfonate.

Particularly preferred among such other acid generators are diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2 2.1] hept-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-tetrafluoroethanesulfonate, cyclohexyl, 2-oxocyclohexyl, methylsulfonium trifluoromethane Sulfonate, dicyclohexyl, 2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium trifluoromethanesulfonate,
Trifluoromethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide Perfluoro-n-octanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2 , 2-tetrafluoroethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide,
N- (trifluoromethanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2.1] Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate and the like. Such acid generators can be used alone or in admixture of two or more.

  In the resin composition of the present invention, the total amount of the acid generator (B) and other acid generator used is based on 100 parts by mass of the resin (A) from the viewpoint of ensuring the sensitivity and developability as a resist. Usually, it is 0.1-20 mass parts, and it is preferable that it is 0.5-10 mass parts. In this case, if the total amount used is less than 0.1 parts by mass, the sensitivity and developability tend to be lowered. On the other hand, when the amount exceeds 20 parts by mass, the transparency to radiation is lowered, and it is difficult to obtain a rectangular resist pattern. Moreover, it is preferable that the usage-amount of another acid generator is 80 mass% or less with respect to the total amount of an acid generator (B) and another acid generator, and it is further 60 mass% or less. preferable.

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 (9) and other nitrogen-containing compounds. Among these, it is preferable that it is a compound represented by following formula (9).

式（９）中においてＲ²¹およびＲ²²は、相互に独立に水素原子、直鎖状、分岐状もしくは環状であり、また置換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Ｒ²¹同士或いはＲ²²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（９）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 (9), R ²¹ and R ²² are each independently a hydrogen atom, linear, branched or cyclic, and optionally substituted alkyl group having 1 to 20 carbon atoms, aryl group or An aralkyl group, or R ²¹ or R ²² are 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 atoms to which they are bonded. Also good.
Examples of the nitrogen-containing compound represented by the above formula (9) include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi- n-decylamine, Nt-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1- Adamantylamine, (S)-(−)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt -Butoxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonylpyrrolidine, N, N'- Di-t-butoxycarbonylpiperazine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl -4,4'-diaminodiphenylmethane, N, N'-di-t-butoxycarbonylhexamethylenediamine, N, N, N ', N'-tetra-t-butoxycarbonylhexamethylenediamine, N, N'-di -T-butoxycarbonyl-1,7-diaminoheptane, N, N'-di-t-butoxycarbonyl-1,8-diaminooctane, N, N'-di-t-butoxycarbonyl-1,9-diaminononane, N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl-1,12-diamino Decane, 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.

Further, as the nitrogen-containing compound (C), in addition to the nitrogen-containing compound represented by the above formula (9), for example, a tertiary amine compound, a quaternary ammonium hydroxide compound, a photodegradable base compound, and other compounds are included. A nitrogen heterocyclic compound etc. can be mentioned.
Examples of the tertiary amine compound include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, and 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（１０）および（１１）におけるＲ²³〜Ｒ²⁷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（１２）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 (10) and an iodonium salt compound represented by the following formula (11).

R ^{23 to} R ²⁷ in the above formulas (10) and (11) 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 (12). .

  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 resin composition of the present invention, the total amount of the nitrogen-containing compound (C) is preferably 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. Less than part by mass is more preferable. When the total amount used exceeds 10 parts by mass, the sensitivity as a resist tends to be remarkably lowered. In addition, if the usage-amount of a nitrogen-containing compound (C) is less than 0.001 mass part, the pattern shape and dimension fidelity as a resist may fall depending on process conditions.

Additive (D):
In the radiation sensitive resin composition of the present invention, a fluorine-containing polymer additive (d-1), an alicyclic skeleton-containing additive (d-2), and a surfactant (d-3) are included as necessary. 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 polymer 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, or by high-speed scanning. Even if liquid immersion exposure is performed, it is a component that has the effect of suppressing liquid immersion-derived defects such as watermark defects without leaving droplets. The structure of the fluorine-containing polymer is not particularly limited. (1) Fluorine-containing polymer that is insoluble in the developer and becomes alkali-soluble by the action of acid, (2) itself is acceptable in the developer. A fluorine-containing polymer which is soluble and increases in alkali solubility by the action of an acid; (3) a fluorine-containing polymer which itself is insoluble in a developer and becomes alkali-soluble by the action of an alkali; (4) itself is developed. Examples thereof include a fluorine-containing polymer that is soluble in a liquid and whose alkali solubility is increased by the action of an alkali.

  The fluorine-containing polymer additive (d-1) having any of the above properties (1) to (4) has at least one of the repeating unit (a-6) and the fluorine-containing repeating unit, and in some cases. Is preferably a polymer further having at least one repeating unit selected from the group consisting of repeating units (a-1) to (a-4) and (a-7).

  Examples of the fluorine-containing repeating unit include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) acrylate, perfluoro n-propyl (meth) acrylate, Fluoro i-propyl (meth) acrylate, perfluoro n-butyl (meth) acrylate, perfluoro i-butyl (meth) acrylate, perfluoro t-butyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, 2- ( 1,1,1,3,3,3-hexafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) pentyl (meth) acrylate, 1 -(2,2,3,3,4,4,5,5-octafluoro) hexyl (Meth) acrylate, perfluorocyclohexylmethyl (meth) acrylate, 1- (2,2,3,3,3-pentafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4,4) 4-heptafluoro) penta (meth) acrylate, 1- (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadeca Fluoro) decyl (meth) acrylate, 1- (5-trifluoromethyl-3,3,4,4,5,6,6,6-octafluoro) hexyl (meth) acrylate and the like.

As the above-mentioned fluorine-containing polymer additive (d-1), for example, repeating units represented by the following formulas (13-1) to (13-5) are preferable. In the following formulas (13-1) to (13-5), R ²⁸ 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;
4- [2-hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7] dodecane, 2-hydroxy-9-methoxycarbonyl-5-oxo-4-oxa - can be exemplified tricyclo [4.2.1.0 ^{3, 7]} nonane. 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 polymers, low-molecular alkali solubility control agents having acid-dissociable protecting groups, 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 film 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 with 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 an ArF excimer laser (wavelength 193 nm) is preferably used 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 in the radiation sensitive resin composition proceeds smoothly. Although the heating conditions for this PEB vary depending on the composition of the radiation sensitive resin composition, it is usually 30 to 200 ° C, preferably 50 to 170 ° 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.
The amount of the organic solvent used is preferably 100 parts by volume or less with respect to 100 parts by volume of the alkaline aqueous solution. When the amount of the organic solvent exceeds 100 parts by volume, the developability is lowered, and there is a possibility that the development residue in the exposed part increases. An appropriate amount of a surfactant or the like may be added to the developer.

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 measurement method of various physical property values and the evaluation method of various properties 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.
[Remaining ratio 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 weight average molecular weight of 500 or less.

[Sensitivity (unit: mJ / cm ² )]:
Using a coater / developer (trade name: CLEAN TRACK ACT8, manufactured by Tokyo Electron Co., Ltd.), a lower antireflection film forming agent (trade name: ARC29A, manufactured by Brewer Science Co., Ltd.) was spin-coated on the surface of an 8-inch silicon wafer. This was subjected to PB under the conditions of 205 ° C. and 60 seconds to form a 77 nm-thick lower layer antireflection film, which was used as a substrate.
Next, using the coater / developer, the surface of the lower antireflection film of the substrate was spin-coated with a coating solution comprising the radiation sensitive resin compositions of Examples and Comparative Examples, and prebaked under the conditions shown in Table 3. By performing (PB), a photoresist film having a thickness of 120 nm was formed. Furthermore, using an ArF excimer laser exposure apparatus (trade name: NSR S306C, manufactured by Nikon Corporation), the mask pattern is applied to the photoresist film under the conditions of NA: 0.78 and Sigma: 0.93 / 0.69. Exposed through. Perform post-exposure baking (PEB) on the above coater / developer hot plate under the conditions shown in Table 3, develop with a 2.38% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 30 seconds, wash with water, and dry. Thus, a positive resist pattern was formed.
In the obtained resist film, the exposure amount (mJ / cm ² ) when a resist pattern having a line width of 90 nm and a distance between the lines of 90 nm (line and space is 1: 1) is formed. ) Was the optimum exposure. Then, this optimum exposure amount was evaluated as sensitivity. A scanning electron microscope (1) (trade name: S-9380, manufactured by Hitachi High-Technologies Corporation) was used to measure the line width and the distance between the lines.
[Resolution (unit: nm)]:
Among the line widths of the line-and-space resist pattern formed in the sensitivity evaluation, the minimum line width (nm) of the lines was used as an evaluation value for resolution (in Table 4, “resolution (nm)”). . The smaller the numerical value, the better the resolution.
[Pattern shape of pattern]:
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) ≦ 1.1 was evaluated as “good”, and the case where it was out of the range was evaluated as “bad”.
[LWR (line roughness characteristic, unit: nm)]:
When observing a 90 nm line-and-space pattern resolved at the optimal exposure for sensitivity evaluation, the line width was observed from the top of the pattern with the same scanning electron microscope used for sensitivity evaluation. Was observed at an arbitrary point, and the measurement variation was evaluated at 3σ (nm).
[Minimum dimensions before collapse (unit: nm)]:
When observing a 90 nm line and space pattern resolved at the optimum exposure amount for sensitivity evaluation, the line width of the resulting pattern is narrow when exposure is performed with an exposure amount larger than the optimum exposure amount. As a result, the resist pattern is finally collapsed. The line width at the maximum exposure amount at which the resist pattern was not confirmed to be collapsed was defined as the minimum dimension before collapse (nm), which was used as an index of pattern collapse resistance. The smaller the line width (minimum dimension before collapse), the better. In addition, the measurement before the minimum collapse (nm) used the same scanning electron microscope as what was used by evaluation of a sensitivity.

[Blob defect]:
First, using the coater / developer (1), an 8-inch silicon wafer subjected to HMDS (hexamethyldisilazane) treatment at 100 ° C. for 60 seconds was prepared. On this 8-inch silicon wafer, the radiation-sensitive resin composition prepared in each example and comparative example was spin coated, and baked (PB) under the conditions shown in Table 3 to form a resist film having a thickness of 120 nm. .
Thereafter, the resist film is exposed to an ArF excimer laser exposure apparatus (trade name “NSR S306C”, manufactured by Nikon Corporation, illumination conditions: NA 0.78, sigma 0.85) through a rubbed glass on which no mask pattern is formed. The exposure was performed at the optimum exposure amount at the above sensitivity. Next, after performing PEB under the conditions shown in Table 3, it was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 30 seconds, washed with water, and dried to produce a blob defect (Blob defect). An evaluation substrate was prepared.
The blob defect evaluation substrate was measured under the trade name “KLA2351” (manufactured by KLA Tencor) to measure blob defects. The evaluation of the blob defect was “good” when the number of detected blob defects was 200 or less, and “bad” when the number of blob defects exceeded 200.

Polymer synthesis:
The polymer was synthesized using monomers (M-1) to (M-5) shown in Table 1 in each synthesis example. Monomers (M-1) to (M-5) are shown in the following formulas (M-1) to (M-5).

Polymer Example 1: Resin (A-1)
40.66 g (40 mol%) of the monomer (M-1), 24.72 g (15 mol%) of the monomer (M-3), and 34.62 g of the monomer (M-4). (45 mol%) was dissolved in 200 g of 2-butanone, and a monomer solution into which 5.27 g of dimethylazobisisobutyrate (indicated as “MAIB” in Table 1) was added as an initiator was prepared.
Next, 100 g of 2-butanone was charged into a 500 ml three-necked flask equipped with 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 added dropwise at a rate of 1.9 ml per minute. 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. Subsequently, it poured into 1500 g of n-heptane, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 300 g of n-heptane, filtered and dried at 50 ° C. for 17 hours to obtain a white powder copolymer (77 g, yield 77%). This copolymer is referred to as “resin (A-1)”.

This copolymer has Mw of 7,310, Mw / Mn of 1.69, and as a result of ¹³ C-NMR analysis, a repeating unit derived from the monomer (M-1) and a monomer ( The content rate of the repeating unit derived from M-4) and the repeating unit derived from the compound (M-3) was 40.3: 44.6: 15.1 (mol%). Moreover, the residual ratio of the low molecular weight component in this copolymer was 0.04% by mass. The measurement results are shown in Table 2.

Polymer Example 2 and Polymer Comparative Examples 1 and 2: Resin (A-2) and Resins (A-3) and (A-4)
Resins (A-2) to (A-4) were synthesized in the same manner as in Polymer Example 1 except that the formulation shown in Table 1 was used.
Moreover, about the obtained resin (A-1)-(A-4), the ratio (mol%) of each repeating unit by ¹³ C-NMR analysis, a yield (%), Mw, dispersity (Mw / Mn) ) And the measurement results of the content (mass%) of the low molecular weight component are shown in Table 2.

Preparation of radiation sensitive resin composition:
Table 3 shows the compositions of the radiation-sensitive resin compositions prepared in each Example and Comparative Example, and pre-exposure and post-exposure heating conditions (PB and PEB). Moreover, each component (acid generator (B), nitrogen-containing compound (C) which comprises radiation sensitive resin compositions other than resin (A-1)-(A-4) synthesize | combined in the said polymer Example. And solvent (E)) are shown below.

Radiation sensitive acid generator (B)
(B-1): 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium / nonafluoro-n-butanesulfonate (B-2): triphenylsulfonium / nonafluoro-n-butanesulfonate (B- 3): 1- (4-n-Butoxynaphthalen-1-yl) tetrahydrothiophenium · 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate nitrogen-containing compound (C)
(C-1): Nt-butoxycarbonyl-2-phenylbenzimidazole additive (D)
(D-1): 4- [2-hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecane solvent (E)
(E-1): Propylene glycol monomethyl ether acetate

Composition Example 1
10 parts by mass of the resin (A-1) obtained in Polymer Example 1, 90 parts by mass of the resin (A-2), and 1- (4-n-butoxynaphthalene-1 as a radiation sensitive acid generator (B) -Yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate (B-1) 4.0 parts by mass, triphenylsulfonium nonafluoro-n-butanesulfonate (B-2) 1.0 part by mass, 1- (4 -N-butoxynaphthalen-1-yl) tetrahydrothiophenium · 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate (B-3) 2.0 parts by mass, containing nitrogen As compound (C), Nt-butoxycarbonyl-2-phenylbenzimidazole (C-1) 0.72 parts by mass, and as additive (D) 4- [2-hydroxy-2,2-bis (toluene) Fluoromethyl) ethyl] tetracyclo [6.2.1.1 ^{3, 6. 02,7} ] 0.02 part by mass of dodecane (D-1) is mixed, 1090 parts by mass of propylene glycol monomethyl ether acetate as a solvent (E) is added to this mixture, and the above mixture is dissolved to obtain a mixed solution. The obtained mixed solution was filtered through a filter having a pore size of 0.20 μm to prepare a radiation sensitive resin composition. Table 3 shows the formulation of the radiation sensitive resin composition.
The obtained radiation sensitive resin composition of Example 1 was evaluated for the sensitivity, resolution, cross-sectional shape of the pattern, LWR (line roughness characteristics), minimum dimension before collapse, and blob defect. The evaluation results are shown in Table 4.

Composition Comparative Example 1
A radiation-sensitive resin composition (Comparative Comparative Example 1) was prepared in the same manner as in Composition Example 1, except that each component for preparing the radiation-sensitive resin composition was changed as shown in Table 3. Obtained. The resulting radiation-sensitive resin composition of Comparative Example 1 was evaluated for sensitivity, resolution, pattern cross-sectional shape, PEB temperature dependency, minimum pre-collapse size, and blob defect. The evaluation results are shown in Table 4.

  As is apparent from Table 4, the radiation-sensitive resin composition of Composition Example 1 was superior in sensitivity and resolution compared to Composition Comparative Example 1. It was also found that dry etching resistance (minimum dimension before collapse) and LWR characteristics were improved. Good results were also obtained for the cross-sectional shape of the pattern and blob defects.

  The radiation-sensitive resin composition of the present invention is used in a lithography process, particularly a lithography process using an ArF excimer laser as a light source, and has a resolution performance in forming a fine pattern of 90 nm or less and also in an immersion exposure process. In addition to being excellent, it can be used as a chemically amplified resist having a low LWR, excellent resistance to pattern collapse, and excellent defectivity.

Claims (2)

A radiation-sensitive resin composition comprising a resin (A) and a radiation-sensitive acid generator (B),
The resin (A) is a repeating unit having a repeating unit (a-1) represented by the following formula (1), a repeating unit (a-2) represented by the following formula (2), and an acid dissociable group. A radiation sensitive resin composition comprising a unit (a-3) and a polymer having a weight average molecular weight of 1,000 to 100,000.

(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, and In 2), R ³ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁴ represents a divalent alicyclic hydrocarbon group having 3 to 9 carbon atoms, a methylene group, or 2 to 9 carbon atoms. Represents a linear or branched alkylene group.) A repeating unit (a-1) represented by the following formula (1), a repeating unit (a-2) represented by the following formula (2), and a repeating unit (a-3) having an acid dissociable group; And having a weight average molecular weight of 1,000 to 100,000.

(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, and In 2), R ³ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁴ represents a divalent alicyclic hydrocarbon group having 3 to 9 carbon atoms, a methylene group, or 2 to 9 carbon atoms. Represents a linear or branched alkylene group.)