JP2010126581A - Polymer and radiation-sensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin and a radiation-sensitive resin composition satisfying excellent resolution, small LWR (Line Width Roughness), good PEB (Post Exposure Bake) temperature dependency, excellent pattern collapse resistance and low defectiveness, that is, excellent in non-defectiveness. <P>SOLUTION: The resin is a copolymer resin (A) of a (meth)acrylic ester of an alcohol having a heterocycle in which a norbornane ring and a lactone ring are condensed and a (meth)acrylic ester of an alcohol having a cyclopentane ring. The radiation-sensitive resin composition includes the resin and a radiation-sensitive acid generator (B). <P>COPYRIGHT: (C)2010,JPO&INPIT

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 is related with the polymer which can be performed. More specifically, the present invention relates to a radiation-sensitive resin composition suitable for a photolithography process using an exposure light source such as far ultraviolet light having a wavelength of 220 nm or less, for example, an ArF excimer laser or an electron beam as a light source.

  The chemically amplified radiation-sensitive resin composition generates an acid in an exposed portion by irradiation with radiation such as far ultraviolet light typified by a KrF excimer laser or an ArF excimer laser. It is a resin composition that forms a resist pattern on a substrate by changing the dissolution rate of an unexposed portion in a developing solution.

When a KrF excimer laser is used as a light source, a chemically amplified radiation-sensitive resin composition mainly composed of a resin having a basic skeleton of polyhydroxystyrene (hereinafter sometimes referred to as “PHS”) having a small absorption in the 248 nm region. By using an object, it is possible to realize high sensitivity, high resolution, and good pattern formation.
On the other hand, for further fine processing, for example, an ArF excimer laser (wavelength: 193 nm) is used as a light source having a shorter wavelength. A compound such as PHS having an aromatic group described above exhibits a large absorption in the 193 nm region corresponding to the wavelength of ArF excimer laser, and therefore cannot be suitably used when an ArF excimer laser is used as a light source. there were. For this reason, a radiation sensitive resin composition containing a resin having an alicyclic hydrocarbon skeleton that does not have a large absorption in the 193 nm region is used as a lithography material using an ArF excimer laser.

Furthermore, it has been found that the resin performance, specifically, the resolution performance is dramatically improved by including, for example, a repeating unit having a lactone skeleton in the resin having the alicyclic hydrocarbon skeleton. (For example, see Patent Documents 1 to 14).
For example, Patent Documents 1 and 2 describe a radiation-sensitive resin composition using a resin containing a repeating unit having a mevalonic lactone skeleton or a γ-butyrolactone skeleton, and Patent Documents 3 to 14 include A radiation-sensitive resin composition using a resin containing a repeating unit having an alicyclic lactone skeleton is described.

  However, in order to cope with further miniaturization with a line width of 90 nm or less, the present resist is not suitable for the radiation-sensitive resin composition simply improved in resolution performance as shown in the above-mentioned patent document. It has become difficult to satisfy various required performances in In the future, as further miniaturization progresses, it is suitably used not only in resolution performance but also in an immersion exposure process that is currently in practical use. For example, low line width roughness (Line Width Roughness, below) , "LWR"), low defect, low post-exposure bake (hereinafter sometimes referred to as "PEB") temperature dependence, development of materials that meet various requirements such as pattern collapse resistance It has been demanded.

In addition, defectability shows the ease of producing the defect 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 caused by the immersion liquid biting bubbles 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 in order to cope with such problems, and not only has excellent resolution performance, but also has a low LWR, good PEB temperature dependency, excellent pattern collapse resistance, and low defectivity. That is, an object of the present invention is to provide a radiation-sensitive resin composition useful as a chemically amplified resist having excellent defects and a polymer that can be used as a resin component in the radiation-sensitive resin composition.

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の整数を表す。Ｒ³は炭素数１〜４のアルキル基を表し、ｎは１〜５の整数を表す。
また、上記重合体が更に下記式（３−１）で表される繰り返し単位および下記式（３−２）で表される繰り返し単位から選ばれた少なくとも１つの繰り返し単位（Ａ３）を含むことを特徴とする。

式（３−１）および式（３−２）において、Ｒ⁴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し、Ｒ⁵は炭素数１〜４のアルキル基を表し、Ｒ⁶は相互に独立に炭素数１〜４のアルキル基を表す。 As a result of intensive studies, the present inventors can solve the above problems by using a polymer containing at least two types of repeating units having a specific chemical structure as a resin component in a radiation-sensitive resin composition. As a result, the present invention has been completed. That is, the polymer of the present invention includes a repeating unit (A1) represented by the following formula (1) and a repeating unit (A2) represented by the following formula (2), and has a weight average molecular weight of 1,000 to 100,000. It is characterized by.

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, and m represents an integer of 1 to 3. R ³ represents an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 1 to 5.
The polymer further contains at least one repeating unit (A3) selected from the repeating unit represented by the following formula (3-1) and the repeating unit represented by the following formula (3-2). Features.

In Formula (3-1) and Formula (3-2), R ⁴ independently represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁵ represents an alkyl group having 1 to 4 carbon atoms. And R ⁶ each independently represents an alkyl group having 1 to 4 carbon atoms.

  The radiation-sensitive resin composition of the present invention is a radiation-sensitive resin composition containing a resin (A) containing the polymer and a radiation-sensitive acid generator (B).

  Since the radiation-sensitive resin composition of the present invention uses a polymer containing at least two types of repeating units having a specific chemical structure as a resin component, it not only has excellent resolution performance, but also has a low LWR and a PEB temperature dependency. Therefore, it can be suitably used as a chemically amplified resist having good properties, excellent resistance to pattern collapse, 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, and is used in the formation of a fine pattern having a line width of 90 nm or less, and also in a liquid immersion exposure process. The various performances as can be shown.

The radiation-sensitive resin composition of the present invention is not limited to the following embodiment, and can be applied to the following embodiment based on 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 is a resin (A) that is a polymer containing the repeating unit (A1) represented by the above formula (1) and the repeating unit (A2) represented by the above formula (2). And a radiation sensitive acid generator (B). Further, a nitrogen-containing compound (hereinafter also referred to as “nitrogen-containing compound (C)”), various additives (hereinafter also referred to as “additive (D)”), a solvent (hereinafter also referred to as “solvent (E)”). Etc. may further be contained. Hereinafter, each component will be described.

Resin (A):
The resin (A) is a polymer containing the repeating unit (A1) represented by the above formula (1) and the repeating unit (A2) represented by the above formula (2).
The alkylene group having 1 to 12 carbon atoms represented by R ² in the 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.
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.
Among these, a methylene group, an ethylene group, a propylene group, and an isopropylene group are preferable.

上記（１−１）〜（１−５）で表される単量体は、単独でも混合物でも使用できる。 Preferable monomers that give the repeating unit (A1) include monomers represented by the following formulas (1-1) to (1-5). In the following formulas (1-1) to (1-5), R ¹ is independently of each other a hydrogen atom or a methyl group, as in the above formula (1).

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

Moreover, it is preferable that the C1-C4 alkyl group represented by R < ³ > in the said Formula (2) is a linear alkyl group or a branched alkyl group, for example, a methyl group, an ethyl group, a propyl group , Isopropyl group, isobutyl group, t-butyl group and the like.

As a preferable thing of the monomer which gives a repeating unit (A2), it is preferable that n is 1-8, for example, (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, 1-methyl (meth) acrylate 1-cyclooctyl ester, and (meth) acrylic acid 1-ethyl-1-cyclooctyl ester, (meth) acrylic acid 1-isopropyl-1-cyclooctyl ester.
The above monomers can be used alone or in a mixture.

The polymer of the present invention has at least one repeating unit (A3) selected from the repeating unit represented by the above formula (3-1) and the repeating unit represented by the above formula (3-2). it can.
The alkyl group having 1 to 4 carbon atoms represented by R ⁵ in the above formula (3-1) is preferably a linear alkyl group or a branched alkyl group, such as a methyl group, an ethyl group, or a propyl group. , Isopropyl group, isobutyl group, t-butyl group and the like.
R ⁶ in the above formula (3-2) independently represents an alkyl group having 1 to 4 carbon atoms, and the alkyl group is preferably a linear alkyl group or a branched alkyl group. Examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an isobutyl group, and a t-butyl group.

Preferred examples of the monomer that gives the repeating unit (3A) include (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid 2-ethyladamantyl-2-yl ester, (meth) ) Acrylic acid 2-n-propyladamantyl-2-yl ester, (meth) acrylic acid 2-isopropyladamantyl-2-yl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester (Meth) acrylic acid 1- (adamantan-1-yl) -1-ethyl ethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylpropyl ester, (meth) acrylic acid 1- (Adamantane-1-yl) -1-ethylpropyl ester and the like can be mentioned.
The above monomers can be used alone or in a mixture.

The polymer may further have one or more types of repeating units other than the repeating units (A1) to (A3) described above (hereinafter sometimes referred to as “other repeating units”).
The other repeating units are repeating units represented by the following formulas (4-1) to (4-6) (hereinafter sometimes referred to as “other repeating units (A4)”), and the following formula (5). A repeating unit represented by the following formula (6) (hereinafter, referred to as “other repeating unit (A6)”). ), A repeating unit represented by the following formula (A7) (hereinafter, also referred to as “other repeating unit (A7)”) can be given as a preferred example.
The present invention has sufficient characteristics of the repeating units (A1) and (A2) by having at least one repeating unit selected from the group consisting of other repeating units (A4) to other repeating units (A7). You can make use of it.

上記式（４−１）〜（４−６）の各式において、Ｒ⁷は互いに独立して、水素原子、メチル基、またはトリフルオロメチル基を表し、Ｒ⁸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、Ｒ⁹は水素原子、またはメトキシ基を表す。また、Ａは単結合またはメチレン基を表し、Ｂは酸素原子またはメチレン基を表す。ｌは１〜３の整数であり、ｍは０または１である。 Other repeating units (A4) are represented by the following formulas (4-1) to (4-6).

In the formulas (4-1) to (4-6), R ⁷ independently represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁸ represents a hydrogen atom or a substituent. Represents an optionally substituted alkyl group having 1 to 4 carbon atoms, and R ⁹ represents a hydrogen atom or a methoxy group. A represents a single bond or a methylene group, and B represents an oxygen atom or a methylene group. l is an integer of 1 to 3, and m is 0 or 1.

Among the monomers giving other repeating units (A4), (meth) acrylic acid-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nona-2 is preferable. -Yl ester, (meth) acrylic acid-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (meth) acrylic acid-5 -Oxo-4-oxa-tricyclo [5.2.1.0 ^3,8 ] dec-2-yl ester, (meth) acrylic acid-10-methoxycarbonyl-5-oxo-4-oxa-tricyclo [5. 2.1.0 ^3,8 ] non-2-yl ester, (meth) acrylic acid-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid -4-methoxycarbonyl-6-oxo-7- Xa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (meth) acrylic Acid-4-methoxycarbonyl-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (meth) acrylic acid-2-oxotetrahydropyran-4-yl ester, (meth) Acrylic acid-4-methyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-ethyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-propyl-2 -Oxotetrahydropyran-4-yl ester, (meth) acrylic acid-2-oxotetrahydrofuran-4-yl ester, (meth) acrylic acid-5,5 -Dimethyl-2-oxotetrahydrofuran-4-yl ester, (meth) acrylic acid-3,3-dimethyl-2-oxotetrahydrofuran-4-yl ester, (meth) acrylic acid-2-oxotetrahydrofuran-3-yl ester , (Meth) acrylic acid-4,4-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5,5-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid -5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid-3,3-dimethyl-5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid-4,4-dimethyl-5-oxo Mention may be made of tetrahydrofuran-2-ylmethyl ester.

上記式（５）において、Ｒ¹⁰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、Ｒ¹¹は炭素数７〜２０の多環型脂環式炭化水素基を表す。この炭素数７〜２０の多環型脂環式炭化水素基は、炭素数１〜４のアルキル基、ヒドロキシル基、シアノ基、および炭素数１〜１０のヒドロキシアルキル基からなる群より選択される少なくとも一種で置換されていても、置換されていなくてもよい。
炭素数７〜２０の多環型脂環式炭化水素基としては、例えば、ビシクロ［２．２．１］ヘプタン、ビシクロ［２．２．２］オクタン、トリシクロ［５．２．１．０^2,6］デカン、テトラシクロ［６．２．１．１^3,6．０^2,7］ドデカン、トリシクロ［３．３．１．１^3,7］デカン等のシクロアルカン類に由来する脂環族環からなる炭化水素基を挙げることができる。 Another repeating unit (A5) is represented by the following formula (5).

In the above formula (5), R ¹⁰ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ¹¹ represents a polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms. The polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms is selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a cyano group, and a hydroxyalkyl group having 1 to 10 carbon atoms. It may be substituted with at least one kind or may not be substituted.
Examples of the polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms include bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, and tricyclo [5.2.1.0 ² ]. ^{, 6} ] decane, tetracyclo [6.2.1.1 ^3,6 . And hydrocarbon groups composed of alicyclic rings derived from cycloalkanes such as 0 ^2,7 ] dodecane and tricyclo [3.3.1.1 ^3,7 ] decane.

These cycloalkane-derived alicyclic rings may have a substituent, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group. , 1-methylpropyl group, t-butyl group and the like, or a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms may be substituted with one or more. These are represented by the following specific examples, but are not limited to those substituted by these alkyl groups, but are hydroxyl groups, cyano groups, hydroxyalkyl groups having 1 to 10 carbon atoms, carboxyls The group may be substituted with oxygen. Moreover, these other repeating units (5) can contain 1 type (s) or 2 or more types.
Among the monomers that give other repeating units (5), (meth) acrylic acid-bicyclo [2.2.1] heptyl ester, (meth) acrylic acid-cyclohexyl ester, (meth) are preferable. Acrylic acid-bicyclo [4.4.0] decanyl ester, (meth) acrylic acid-bicyclo [2.2.2] octyl ester, (meth) acrylic acid-tricyclo [5.2.1.0 ^2,6 ] Decanyl ester, (meth) acrylic acid-tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecanyl ester, (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 ] decanyl ester, and the like.

上記式（６）において、Ｒ¹²は水素原子、炭素数１〜４のアルキル基、トリフルオロメチル基、またはヒドロキシメチル基を表し、Ｒ¹³は、２価の鎖状または環状の炭化水素基を表す。 Another repeating unit (A6) is represented by the following formula (6).

In the above formula (6), R ¹² represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, or a hydroxymethyl group, and R ¹³ represents a divalent chain or cyclic hydrocarbon group. To express.

R ¹³ of the other repeating unit (A6) represented by the above formula (6) is a divalent chain or cyclic hydrocarbon group as described above, such as an alkylene glycol group or an alkylene ester group. May be. Preferred R ¹³ is a methylene group, an ethylene group, a propylene group such as a 1,3-propylene group or a 1,2-propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, Nonamethylene group, Decamemethylene group, Undecamethylene group, Dodecamethylene group, Tridecamethylene group, Tetradecamethylene group, Pentadecamethylene group, Hexadecamethylene group, Heptadecamethylene group, Octadecamethylene group, Nonadecamethylene group, Insalen group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl- 1,4-butylene group, methylidene group, ethylidene group, propylidene group, or 2-propylidene group A saturated chain hydrocarbon group such as an ethylene group; a cyclobutylene group such as a 1,3-cyclobutylene group; a cyclopentylene group such as a 1,3-cyclopentylene group; a cyclohexylene such as a 1,4-cyclohexylene group A monocyclic hydrocarbon ring group such as a cycloalkylene group having 3 to 10 carbon atoms such as a cyclooctylene group such as a 1,5-cyclooctylene group; a 1,4-norbornylene group or a 2,5-norbornylene group Such as norbornylene group, 1,5-adamantylene group, adamantylene group such as 2,6-adamantylene group, etc., bridged cyclic hydrocarbon ring such as 2-4 cyclic hydrocarbon ring group having 4-30 carbon atoms Examples include groups.

Among the monomers giving other repeating units (A6), (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-3-propyl) ester is preferable. (Meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trimethyl) Fluoromethyl-2-hydroxy-5-pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester, (meth) acrylic acid 2 -{[5- (1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl] bicyclo [2.2.1] heptyl} ester, (meth) Acrylic acid 4 - {[9- (1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl] tetracyclo [6.2.1.1 ^{3, 6.} 0 ^2,7 ] dodecyl} ester and the like.

上記式（７）において、Ｒ¹⁴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、Ｒ¹⁵は互いに独立して、水素原子、水酸基、シアノ基、または−ＣＯＯＲ¹⁶基を表す。但し、Ｒ¹⁶は水素原子、炭素数１〜４の直鎖状もしくは分岐状のアルキル基、または炭素数３〜２０の脂環式のアルキル基を表す。上記式（７）においては、３つのＲ¹⁵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 (A7) is represented by the following formula (7).

In the above formula (7), R ¹⁴ 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 carbon. represents a divalent organic group having 1 to 3, R ¹⁵ each independently represent a hydrogen atom, a hydroxyl group, a cyano group or a -COOR ¹⁶ group,. R ¹⁶ represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic alkyl group having 3 to 20 carbon atoms. In the above formula (7), when at least one of the three R ¹⁵ is not a hydrogen atom and Y ¹ is a single bond, at least one of the three Y ² is 2 having 1 to 3 carbon atoms. A valent organic group is preferred.

In another repeating unit (A7) represented by the formula (7), 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. A divalent organic group having 1 to 3 carbon atoms is shown, and examples of the divalent organic group having 1 to 3 carbon atoms represented by Y ¹ and Y ² include a methylene group, an ethylene group, and a propylene group.

R ¹⁶ of the —COOR ¹⁶ group in R ¹⁵ of the formula (7) is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic alkyl group having 3 to 20 carbon atoms. In the R ¹⁶ , the linear or branched alkyl group having 1 to 4 carbon atoms includes methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2 -Methylpropyl group, 1-methylpropyl group, t-butyl group can be mentioned.
Examples of the alicyclic alkyl group having 3 to 20 carbon atoms _{^{R 16, -C n H 2n-}} 1 cycloalkyl group (n is an integer of 3 to 20) represented by the polycyclic alicyclic An alkyl group etc. can be mentioned. 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.

  Among the monomers that give other repeating units (A7), (meth) acrylic acid 3-hydroxyadamantan-1-yl ester, (meth) acrylic acid 3,5-dihydroxyadamantan-1-yl Ester, (meth) acrylic acid 3-hydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-methyladamantane- 1-yl ester, (meth) acrylic acid 3,5-dihydroxy-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-yl ester, (meth) 3-hydroxy-5,7-dimethyladamantan-1-ylmethylacrylate Mention may be made of the ether and the like.

Moreover, the polymer used as resin (A) contained in the radiation sensitive resin composition of this invention is the repeating unit (A1)-(A3) shown by said Formula (1)-(3), and It may further have a repeating unit other than the other repeating units (A4) to (A7) represented by the formulas (4) to (7) (hereinafter sometimes referred to as “other repeating units”).
Examples of such other repeating units include (meth) acrylic acid esters having a bridged hydrocarbon skeleton such as dicyclopentenyl (meth) acrylate and adamantylmethyl (meth) acrylate; Carboxyl group-containing esters having a bridged hydrocarbon skeleton of an unsaturated carboxylic acid such as carboxynorbornyl acrylate, carboxytricyclodecanyl (meth) acrylate, carboxytetracycloundecanyl (meth) acrylate; Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-methylpropyl (meth) acrylate, 1-methyl (meth) acrylate Propyl, t-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth ) 2-hydroxypropyl acrylate, 3-hydroxypropyl (meth) acrylate, cyclopropyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, 4-methoxycyclohexyl (meth) acrylate, It also has a bridged hydrocarbon skeleton such as 2-cyclopentyloxycarbonylethyl (meth) acrylate, 2-cyclohexyloxycarbonylethyl (meth) acrylate, 2- (4-methoxycyclohexyl) oxycarbonylethyl (meth) acrylate, etc. (Meth) acrylic esters; α-hydroxy such as methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, n-propyl α-hydroxymethyl acrylate, n-butyl α-hydroxymethyl acrylate, etc. Methyla Unsaturated nitrile compounds such as (meth) acrylonitrile, α-chloroacrylonitrile, crotonnitrile, maleinonitrile, fumaronitrile, mesacononitrile, citracononitrile, itaconnitrile; (meth) acrylamide, N, N-dimethyl ( Unsaturated amide compounds such as (meth) acrylamide, crotonamide, maleamide, fumaramide, mesaconamide, citraconamide, itaconamide; N- (meth) acryloylmorpholine, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, vinylpyridine, Other nitrogen-containing vinyl compounds such as vinylimidazole; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride Unsaturated carboxylic acids (anhydrides) such as mesaconic acid; 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, (meth) acrylic acid 4 -Carboxy group-containing esters having no bridged hydrocarbon skeleton of unsaturated carboxylic acid such as carboxybutyl, 4-carboxycyclohexyl (meth) acrylate; 1,2-adamantanediol di (meth) acrylate, 1, A polyfunctional monomer having a bridged hydrocarbon skeleton such as 3-adamantanediol di (meth) acrylate, 1,4-adamantanediol di (meth) acrylate, tricyclodecanyldimethylol di (meth) acrylate; Methylene glycol di (meth) acrylate, ethylene glycol di (meth) acryl Propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2,5-dimethyl-2,5-hexanediol di (meth) acrylate, 1,8-octanediol di (meth) ) Acrylate, 1,9-nonanediol di (meth) acrylate, 1,4-bis (2-hydroxypropyl) benzenedi (meth) acrylate, 1,3-bis (2-hydroxypropyl) benzenedi (meth) acrylate, etc. Examples thereof include a unit in which a polymerizable unsaturated bond of a polyfunctional monomer such as a polyfunctional monomer having no bridged hydrocarbon skeleton is cleaved.

  In the polymer of the present invention, the content of the repeating unit (A1) is preferably 10 to 85 mol%, more preferably 20 to 80 mol%, more preferably 30 to 70, based on all repeating units. It is particularly preferred that it is mol%. By comprising in this way, the developability as a resist which uses this polymer as a resin component, defect property, LWR, PEB temperature dependency, etc. can be improved. For example, if the content of the repeating unit (A1) is less than 10 mol%, the developability and defectability as a resist may be deteriorated, and if it exceeds 85 mol%, the resolution as a resist, LWR, PEB temperature Dependency may be degraded.

  Moreover, it is preferable that it is 10-85 mol% with respect to all the repeating units, and, as for the content rate of a repeating unit (A2), it is still more preferable that it is 20-80 mol%, and it is 30-70 mol%. Is particularly preferred. By comprising in this way, the developability as a resist, defect property, LWR, PEB temperature dependency, etc. can be improved. For example, when the content of the repeating unit (A2) is less than 10 mol%, the resolution as a resist, LWR, and PEB temperature dependency may be deteriorated. On the other hand, when the content exceeds 85 mol%, the developability as a resist. , Defect may be deteriorated.

  Moreover, it is preferable that it is 5-70 mol% with respect to all the repeating units, and, as for the content rate of a repeating unit (A3), it is still more preferable that it is 5-60 mol%, and it is 10-50 mol%. Is particularly preferred. By configuring in this way, resistance to pattern collapse as a resist, resolution, LWR, PEB temperature dependency, and the like can be improved. For example, if the content of the repeating unit (A3) is less than 5 mol%, the resistance to pattern collapse as a resist may be deteriorated. On the other hand, if it exceeds 70 mol%, the resolution as a resist depends on LWR and PEB temperatures. May deteriorate.

The other repeating units (A4) to (A7) and the further other repeating units are optional constituents. For example, the content of the other repeating units (A4) may be all repeating units. Is preferably 30 mol% or less, and more preferably 25 mol% or less. For example, if the content of other repeating units (A4) exceeds 30 mol%, the defect as a resist may be deteriorated.
Moreover, it is preferable that it is 30 mol% or less with respect to all the repeating units, and, as for the content rate of another repeating unit (A5), it is still more preferable that it is 25 mol% or less. For example, if the content of other repeating units (A5) exceeds 30 mol%, the resist film may be easily swollen by an alkali developer, or the developability as a resist may be reduced.
Moreover, it is preferable that it is 30 mol% or less with respect to all the repeating units, and, as for the content rate of another repeating unit (A6), it is still more preferable that it is 25 mol% or less. For example, if the content of other repeating units (A6) exceeds 30 mol%, the top loss of the resist pattern may occur and the pattern shape may deteriorate.
Moreover, it is preferable that it is 30 mol% or less with respect to all the repeating units, and, as for the content rate of another repeating unit (A7), it is still more preferable that it is 25 mol% or less. For example, if the content of other repeating units (A7) 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 the polymer demonstrated until now is demonstrated.
The polymer can be synthesized according to a conventional method such as radical polymerization. For example, a reaction solution containing each monomer and a radical initiator is dropped into a reaction solvent or a reaction solution containing a monomer. The reaction solution containing each monomer and the reaction solution containing a radical initiator are dropped separately into the reaction solution containing the reaction solvent or the monomer, respectively, and the polymerization reaction is performed, Further, there is a method in which a reaction solution prepared separately for each monomer and a reaction solution containing a radical initiator are separately dropped into a reaction solution containing a reaction solvent or a monomer to cause a polymerization reaction. preferable.

  The reaction temperature in each of the above reactions can be appropriately set depending on the type of initiator to be used. In addition, it is preferable that the reaction temperature in said each reaction is 40 to 160 degreeC, and it is still more preferable that it is 50 to 140 degreeC. The time required for dropping can be variously set depending on the reaction temperature, the type of initiator, and the monomer to be reacted, but it is preferably 30 minutes to 8 hours, more preferably 45 minutes to 6 hours. It is particularly preferred that the time is 5 hours. The total reaction time including the dropping time can be variously set as described above, but is preferably 30 minutes to 8 hours, more preferably 45 minutes to 7 hours, and 1 hour to 6 hours. It is particularly preferred. When dripping into the solution containing the monomer, the content ratio of the monomer in the dripped solution is preferably 30 mol% or more, more preferably 50 mol% or more based on the total amount of monomers used for the polymerization. More preferably, it is particularly preferably 70 mol% or more.

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

As a solvent used for the polymerization, any solvent can be used as long as it does not dissolve the monomer used and inhibits the polymerization. Examples of the solvent that inhibits polymerization include solvents that prohibit polymerization, such as nitrobenzenes, and solvents that cause chain transfer, such as mercapto compounds.
Examples of the solvent that can be suitably used for the polymerization include alcohols, ethers, ketones, amides, esters and lactones, nitriles, and a mixture of these solvents. Examples of alcohols include methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and 1-methoxy-2-propanol. Examples of ethers include propyl ether, isopropyl ether, butyl methyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, and 1,3-dioxane. Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, and methyl isobutyl ketone. Examples of amides include N, N-dimethylformamide and N, N-dimethylacetamide. Examples of esters and lactones include ethyl acetate, methyl acetate, isobutyl acetate, and γ-butyrolactone. Examples of nitriles include acetonitrile, propionitrile, and butyronitrile. These solvents can be used alone or in admixture of two or more.

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

In addition, although the low molecular weight component derived from the monomer demonstrated so far is contained in a polymer, the content rate is 0.1 mass% or less with respect to the total amount (100 mass%) of a polymer. Preferably, it is 0.07% by mass or less, more preferably 0.05% by mass or less.
When the content ratio of the 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 when performing immersion exposure. The amount of eluate in the water can be reduced. Furthermore, foreign matters are not generated in the resist during resist storage, and coating unevenness does not occur during resist application, and the occurrence of defects during resist pattern formation can be sufficiently suppressed.

In the present invention, the low molecular weight component derived from the monomer includes a monomer, a dimer, a trimer, and an oligomer. The weight average molecular weight in terms of polystyrene by gel permeation chromatography (GPC) (hereinafter referred to as “Mw”) Is a component of 500 or less. The components having an Mw of 500 or less can be removed by, for example, chemical purification methods such as washing with water and liquid-liquid extraction, or a combination of these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. it can.
The low molecular weight component can be analyzed by high performance liquid chromatography (HPLC) of the polymer. In addition, the polymer used as the resin (A) is preferably as little as possible as impurities such as halogens and metals. Thereby, the sensitivity, resolution, process stability, pattern shape, and the like of the resist can be further improved.
Moreover, the polystyrene conversion weight average molecular weight (Mw) by gel permeation chromatography (GPC) of this polymer is not particularly limited, but is preferably 1000 to 100,000, more preferably 1000 to 30000, and 1000 to It is especially preferable that it is 20000. In this case, if the Mw of the polymer is less than 1000, the heat resistance when used as a resist tends to be reduced, whereas if it exceeds 100,000, the developability when used as a resist tends to be reduced. Further, the ratio (Mw / Mn) of the polymer Mw to the polystyrene-equivalent number average molecular weight (hereinafter sometimes referred to as “Mn”) by gel permeation chromatography (GPC) is 1.0 to 5.0. It is preferable that it is 1.0-3.0, and it is especially preferable that it is 1.0-2.0.
In this invention, when producing a radiation sensitive resin composition using a polymer, a polymer can be used individually or in mixture of 2 or more types.

Radiation sensitive acid generator (B):
The radiation-sensitive acid generator (B) (hereinafter sometimes simply referred to as “acid generator (B)”) contained in the radiation-sensitive resin composition of the present invention generates an acid upon exposure. Functions as a photoacid generator. This acid generator uses an acid generated by exposure to dissociate an acid-dissociable group present in the resin (A) contained in the radiation-sensitive resin composition (eliminate a protective group), and (A) is alkali-soluble. As a result, the exposed portion of the resist film becomes readily soluble in an alkaline developer, thereby forming a positive resist pattern.
As said acid generator (B), what contains the compound represented by following formula (8) is preferable.

式（８）において、Ｒ¹⁷は水素原子、フッ素原子、水酸基、炭素原子数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、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す。Ｒ¹⁸は炭素数１〜１０の直鎖状もしくは分岐状のアルキル基、アルコキシル基もしくは炭素数１〜１０の直鎖状、分岐状、環状のアルカンスルホニル基を表す。Ｒ¹⁹は相互に独立に炭素数１〜１０の直鎖状もしくは分岐状のアルキル基、置換されていてもよいフェニル基または置換基されていてもよいナフチル基を表すか、あるいは、２個のＲ¹⁹が互いに結合して炭素数２〜１０の２価の基を形成しており、該２価の基は置換されていてもよい。ｋは０〜２の整数である。Ｘ^-は式：Ｒ²⁰Ｃ_nＦ_2nＳＯ₃ ^-（式中、Ｒ²⁰は、水素原子、フッ素原子、あるいは、置換基されていてもよい炭素数１〜１２の炭化水素基を表し、ｎは１〜１０の整数である）で表されるアニオン、Ｒ²⁰ＳＯ₃ ^-で表されるアニオン、または下記式（９−１）もしくは（９−２）で表されるアニオンを示す。ｒは０〜１０の整数であり、０〜２の整数が好ましい。

In the formula (8), R ¹⁷ 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, A linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms is represented. R ¹⁸ represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxyl group, or a linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms. R ¹⁹ represents each independently a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group or an optionally substituted naphthyl group, or two R ¹⁹ are bonded to each other to form a divalent group having 2 to 10 carbon atoms, and the divalent group may be substituted. k is an integer of 0-2. X ⁻ represents a formula: R ²⁰ C _n F _2n SO ₃ ⁻ (wherein R ²⁰ represents a hydrogen atom, a fluorine atom, or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms; the anion represented by a is) integer of from 1 to 10, R ²⁰ SO ₃ ^- represents an anion represented by an anion represented or formula (9-1) or (9-2). r is an integer of 0 to 10, and an integer of 0 to 2 is preferable.

式（９−１）および（９−２）において、Ｒ²¹は相互に独立に炭素数１〜１０の直鎖状もしくは分岐状のフッ素原子を含有するアルキル基を表すか、あるいは、２個のＲ²¹が互いに結合して炭素数２〜１０の２価のフッ素原子を含有する基を形成しており、該２価の基は置換されていてもよい。

In the formulas (9-1) and (9-2), R ²¹ represents each independently an alkyl group containing a linear or branched fluorine atom having 1 to 10 carbon atoms, or two R ²¹ are bonded to each other to form a group containing a divalent fluorine atom having 2 to 10 carbon atoms, and the divalent group may be substituted.

In the formula (8), examples of the linear or branched alkyl group having 1 to 10 carbon atoms of R ¹⁷ , R ¹⁸ and R ¹⁹ include a methyl group, an ethyl group, an n-propyl group, and an 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-ethylhexyl group , N-nonyl group, n-decyl group and the like. 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 alkoxy group having 1 to 10 carbon atoms R ¹⁷ and R ^18, for example, a methoxy group, an ethoxy group, n- propoxy group, i- propoxy, n- butoxy 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-ethylhexyloxy group , N-nonyloxy group, n-decyloxy group and the like. 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 of R ¹⁷ include, for example, a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, and an n-butoxycarbonyl group. Group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, n-heptyloxycarbonyl group, n -An octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group, etc. can be mentioned. 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 of R ¹⁸ include a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, and a tert- Butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group n-nonanesulfonyl group, n-decanesulfonyl group , Cyclopentanesulfonyl group, cyclohexanesulfonyl group and the like. 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 (8), examples of the optionally substituted phenyl group for R ¹⁹ include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, 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, 4- Phenyl substituted with phenyl group such as 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 Group; these phenyl group or alkyl-substituted phenyl group can be substituted with hydroxyl group, carboxyl group, cyano group, nitro group, alkoxyl group, alkoxyalkyl group, Alkoxycarbonyl group, group obtained by substituting at least one group in such alkoxycarbonyloxy group and the like.
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 straight-chain, branched or cyclic alkoxyl groups having 1 to 20 carbon atoms such as methylpropoxy group, t-butoxy group, cyclopentyloxy group and 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 linear, branched or cyclic alkoxycarbonyl groups 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 ¹⁹ in the formula (8) 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 ¹⁹ 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-methyl A naphthyl group substituted with a naphthyl group such as a 2-naphthyl group or 4-methyl-2-naphthyl group or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms; these naphthyl groups or alkyl substitutions Examples include a group obtained by substituting a naphthyl group with at least one of a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, and the like. .
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.
As the naphthyl group which may be substituted in R ¹⁹ in the above formula (8), 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 ¹⁹ to each other, together with the sulfur atom in the above formula (8), 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 include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxy group exemplified as the substituent for the phenyl group and the alkyl-substituted phenyl group. Examples thereof include a carbonyl group and an alkoxycarbonyloxy group.
As R ¹⁹ in the formula (8), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, a 1-naphthyl group, and two R ¹⁹ 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 (8) 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-hydroxynaphthalen-1-yl) dimethylsulfonium cation 1- (4-methylnaphthalen-1-yl) dimethylsulfonium cation, 1- (4-methylnaphthalen-1-yl) diethylsulfonium cation, 1- (4-cyanonaphthalen-1-yl) dimethylsulfonium cation, 1- (4-cyanonaphthalen-1-yl) diethylsulfonium cation, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium cation, 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium Cations, 1- (4-ethoxynaphthalen-1-yl) tetrahydrothiophenium cation, 1- (4-n-propoxynaphthalen-1-yl) tetrahydrothiophenium cation, 1- (4-n-butoxynaphthalene- 1-yl) tetrahydrothiophenium 2- (7-methoxynaphthalen-2-yl) tetrahydrothiophenium cation, 2- (7-ethoxynaphthalen-2-yl) tetrahydrothiophenium cation, 2- (7-n-propoxynaphthalene-2- Yl) tetrahydrothiophenium cation, 2- (7-n-butoxynaphthalen-2-yl) tetrahydrothiophenium cation, and the like.

The R ²⁰ C _n F _2n SO ₃ ^— anion represented by X ⁻ in the above formula (8) is a C _n F _2n — group, which is a perfluoroalkylene group having n carbon atoms. Or it can be branched. Here, n is preferably 1, 2, 4 or 8. The _optionally substituted hydrocarbon group having 1 to 12 carbon atoms in R ²⁰ in R ²⁰ C _n F _2n SO ₃ ^— and R ²⁰ SO ₃ ^— anion includes an alkyl group having 1 to 12 carbon atoms, cyclo An alkyl group and a bridged alicyclic hydrocarbon group 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 the above formulas (9-1) and (9-2), R ²¹ independently represents an alkyl group containing a linear or branched fluorine atom having 1 to 10 carbon atoms, such as a trifluoromethyl group or pentafluoroethyl. Group, heptafluoropropyl group, nonafluorobutyl group, dodecafluoropentyl group, perfluorooctyl group and the like.
Examples of the group containing two R ²¹ bonded to each other and containing a divalent fluorine atom having 2 to 10 carbon atoms include a tetrafluoroethylene group, a hexafluoropropylene group, an octafluorobutylene group, a decafluoropentylene group, A decafluorohexylene group etc. can be mentioned.

  Preferred anion sites of the above formula (8) include 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 and The anion etc. which are mentioned by Formula (10-1)-(10-7) can be mentioned.

  The acid generator (B) is given by a combination of the cation and anion exemplified above, but the combination is not particularly limited. In the present invention, the acid generator (B) may be used alone or in combination of two kinds. Even if the above is mixed, it can be used.

  Moreover, as a radiation sensitive acid generator (henceforth "other acid generator") other than the said acid generator (B) which can be used as a radiation sensitive acid generator in this invention, it is, for example. Onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, sulfonic acid compounds, and the like. Examples of these other acid generators include the following.

  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- Te La tetrafluoroethane sulfonate, cyclohexyl 2-oxo-cyclohexyl methyl trifluoromethanesulfonate, dicyclohexyl-2-oxo-cyclohexyl trifluoromethane sulfonate, and 2-oxo-cyclohexyl dimethyl sulfonium trifluoromethanesulfonate, and the like.

  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 and 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane.

  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 diazoketone 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, 1,1,1-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 compound 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- (trifluoromethanesulfonyl Xyl) 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, 1,8-naphthalenedicarboxylic acid Examples include acid imido perfluoro-n-octane sulfonate.
Such acid generators can be used alone or in admixture of two or more.

  In the radiation sensitive resin composition of the present invention, the total amount of the acid generator (B) and the other acid generator used is 100 parts by mass of the resin (A) from the viewpoint of ensuring the sensitivity and developability as a resist. On the other hand, it is preferable that it is 0.1-20 mass parts, and it is still more 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 decrease. On the other hand, if it exceeds 20 parts by mass, the transparency to radiation decreases and a rectangular resist pattern is obtained. It tends to be difficult. Moreover, it is preferable that the usage-amount of another acid generator is 80 mass% or less with respect to the sum total 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 such a nitrogen-containing compound (C), the storage stability of the resulting radiation-sensitive resin composition is improved, the resolution as a resist is further improved, and from exposure to heat treatment after exposure. The change in the line width of the resist pattern due to fluctuations in the holding time (PED) of the resist can be suppressed, and a composition having extremely excellent process stability can be obtained.

  As this nitrogen-containing compound (C), for example, a nitrogen-containing compound (c1) represented by the following formula (11) can be suitably used.

式（１１）中においてＲ²²およびＲ²³は、相互に独立に水素原子、直鎖状、分岐状もしくは環状の置換基されていてもよい炭素数１〜２０のアルキル基、アリール基またはアラルキル基、或いはＲ²²同士或いはＲ²³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（１１）で表される窒素含有化合物（ｃ１）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 (11), R ²² and R ²³ are each independently a hydrogen atom, a linear, branched or cyclic substituent group having 1 to 20 carbon atoms, an aryl group or an aralkyl group. or attached R ²² together or R ²³ with each other to each other, together with the carbon atom to which each is attached may form a divalent saturated or unsaturated hydrocarbon group or a derivative thereof having 4 to 20 carbon atoms .
Examples of the nitrogen-containing compound (c1) represented by the above formula (11) include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxy. Carbonyl di-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, N -T-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 Diaminododecane, N, N′-di-t-butoxycarbonyl-4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxy Examples include Nt-butoxycarbonyl group-containing amino compounds such as carbonyl-2-phenylbenzimidazole.

Further, as the nitrogen-containing compound (C), in addition to the nitrogen-containing compound (c1) represented by the above formula (11), for example, a tertiary amine compound, a quaternary ammonium hydroxide compound, a photodegradable base compound And other nitrogen-containing heterocyclic compounds.
Examples of tertiary amine compounds include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octyl. Tri (cyclo) alkylamines such as amine, cyclohexyldimethylamine, dicyclohexylmethylamine, tricyclohexylamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methyl Aromatic amines such as aniline, 4-nitroaniline, 2,6-dimethylaniline, 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.
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 (12-1) and an iodonium salt compound represented by the following formula (12-2).

上記式（１２−１）および（１２−２）におけるＲ²⁴〜Ｒ²⁸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（１３）で表されるアニオンを表す。

R ^{24 to} R ²⁸ in the above formulas (12-1) and (12-2) each independently represent a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom.
Z ⁻ represents OH ⁻ , R—COO ⁻ , R—SO ₃ ⁻ (wherein R represents an alkyl group, an aryl group, or an alkanol group), or an anion represented by the following formula (13). .

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

Examples of the nitrogen-containing heterocyclic compound include pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine. , Nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine and other pyridines; piperazine, piperazines such as 1- (2-hydroxyethyl) piperazine, pyrazine, pyrazole, Pyridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane, imidazole 4-methylimidazole, 1 Benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, and 2-phenylbenzimidazole, and the like.
Such nitrogen-containing compounds (C) can be used alone or in admixture of two or more.

  In the radiation-sensitive resin composition of the present invention, the content ratio of the nitrogen-containing compound (C) is less than 10 parts by mass with respect to 100 parts by mass of the resin (A) from the viewpoint of ensuring high sensitivity as a resist. Preferably, it is less than 5 parts by mass. In this case, when the content ratio of the nitrogen-containing compound (C) exceeds 10 parts by mass, the sensitivity as a resist tends to be significantly reduced. In addition, if the content rate of a nitrogen-containing compound (C) is less than 0.001 mass part, there exists a possibility that the pattern shape and dimension fidelity as a resist may fall depending on process conditions.

Additive (D):
In the radiation-sensitive resin composition of the present invention, a fluorine-containing resin additive (d1), an alicyclic skeleton-containing additive (d2), a surfactant (d3), and a sensitizer (d4) are optionally included. Etc. Various additives (D), such as, can be mix | blended. The content ratio of each additive can be appropriately determined according to the purpose.

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

The above-mentioned fluorine-containing resin additive (d1) preferably contains at least one repeating unit selected from the group consisting of the other repeating units (A6) and the following fluorine-containing repeating units. , Further containing at least one repeating unit selected from the group consisting of the repeating units (A1) to (A3), the other repeating units (A4), (A5), (A7), and the other repeating units. More preferably.
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, Perfluoro i-propyl (meth) acrylate, perfluoro n-butyl (meth) acrylate, perfluoro i-butyl (meth) acrylate, perfluoro t-butyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, 2- (1,1,1,3,3,3-hexafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) pentyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) hex (Meth) acrylate, perfluorocyclohexylmethyl (meth) acrylate, 1- (2,2,3,3,3-pentafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4, 4,4-Heptafluoro) penta (meth) acrylate, 1- (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10- Examples include heptadecafluoro) decyl (meth) acrylate, 1- (5-trifluoromethyl-3,3,4,4,5,6,6,6-octafluoro) hexyl (meth) acrylate, and the like.

As a fluorine-containing resin additive (d1), the polymer which has a repeating unit represented by following formula (14-1)-(14-6) can be mentioned as a suitable example, for example. In the following formulas (14-1) to (14-6), R ²⁹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

The alicyclic skeleton-containing additive (d2) as the additive (D) is a component having an action of further improving dry etching resistance, pattern shape, adhesion to the substrate, and the like.
Examples of such alicyclic skeleton-containing additive (d2) include 1-adamantanecarboxylic acid, 2-adamantanone, 1-adamantanecarboxylate t-butyl, 1-adamantanecarboxylate t-butoxycarbonylmethyl, 1 -Adamantanecarboxylic acid α-butyrolactone ester, 1,3-adamantane dicarboxylic acid di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t -Adamantane derivatives such as 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; tert-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, 2-cyclohexyloxyethyl lithocholic acid, 3-oxocyclohexyl lithocholic acid Lithocholic acid esters such as tetrahydropyranyl acid, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-adipate Chill, alkyl carboxylic acid esters such as adipate t- butyl;
3- [2-Hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, 2-hydroxy-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nonane, and the like. These alicyclic skeleton-containing additives (d2) can be used alone or in admixture of two or more.
The surfactant (d3) as the additive (D) is a component that exhibits an effect of improving coatability, striation, developability, and the like.
Examples of such surfactant (d3) include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, In addition to nonionic surfactants such as polyethylene glycol dilaurate and polyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), Ftop EF301, EF303, EF352 (manufactured by Tochem Products), Megafax F171, F173 (manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (manufactured by Asahi Glass Co., Ltd.), etc. Can do. These surfactants can be used alone or in admixture of two or more.

The sensitizer (d4) as the additive (D) absorbs the energy of radiation 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 (d4) 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 pigment as the additive (D), the latent image in the exposed area can be visualized, and the influence of halation during exposure can be reduced. Moreover, adhesiveness with a board | substrate can be improved by using an adhesion assistant as an additive (D). Furthermore, examples of additives other than the above include alkali-soluble resins, low-molecular alkali solubility control agents having an acid-dissociable protecting group, antihalation agents, storage stabilizers, antifoaming agents, and the like.
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. In the chemically amplified resist, the resin component, mainly the acid dissociable group in the resin (A), is dissociated by the action of the acid generated from the acid generator by exposure to generate a carboxyl group. As a result, the resist The solubility of the exposed portion in the alkaline developer is increased, and the exposed portion is dissolved and removed by the alkaline developer to obtain a positive photoresist pattern.
As a method of forming a photoresist pattern using the radiation-sensitive resin composition of the present invention, (1) a step of forming a photoresist film on a substrate using the radiation-sensitive resin composition of the present invention (hereinafter referred to as “photoresist pattern”) (Sometimes referred to as “step (1)”), and (2) a step of exposing the formed photoresist film to radiation through a mask having a predetermined pattern, possibly via an immersion medium, and exposing. (Hereinafter also referred to as “step (2)”) and (3) a step of developing the exposed photoresist film to form a photoresist pattern (hereinafter also referred to as “step (3)”). And.

Further, when performing immersion exposure, an immersion-insoluble immersion protective film is formed before the step (2) in order to protect the direct contact between the immersion liquid and the resist film as necessary. It can be provided on the membrane. As the immersion protective film used at this time, for example, a solvent peeling type immersion protective film disclosed in JP-A-2006-227632 or the like, which is peeled off by a solvent before the above step (3), or a process There is a developer peeling type immersion protective film which is peeled off simultaneously with the development of (3), for example, disclosed in WO2005-069096 and WO2006-035790, but is not particularly limited. However, considering the throughput and the like, it is generally preferable to use the latter developer-peeling type immersion protective film.
In the step (1), the resin composition solution obtained by dissolving the radiation-sensitive resin composition of the present invention in a solvent is applied by appropriate application means such as spin coating, cast coating, roll coating, etc. A photoresist film is formed by applying on a substrate such as a silicon wafer or a wafer coated with silicon dioxide. Specifically, after applying the radiation-sensitive resin composition solution so that the resulting resist film has a predetermined thickness, the solvent in the coating film is volatilized by pre-baking (PB) to form a resist film. Is done.
The thickness of the resist film is not particularly limited, but is 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 preferable that it is about 30-200 degreeC, and it is still more preferable that it is 50-150 degreeC.

  In the method for forming a photoresist pattern using the radiation-sensitive resin composition of the present invention, for example, in order to maximize the potential of the radiation-sensitive resin composition, for example, Japanese Patent Publication No. 6-12458 (Japanese Patent Laid-Open No. 6-12852). As disclosed in JP-A-59-93448), an organic or inorganic antireflection film may be formed on a substrate to be used. 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. Further, the above-described immersion protective film can be provided on the photoresist film. These techniques can be used in combination.

In the step (2), the photoresist film formed in the step (1) is irradiated with radiation through an immersion medium such as water depending on the case to expose the photoresist film. In this case, radiation is irradiated through a mask having a predetermined pattern.
As the radiation, visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams, and the like are appropriately selected and used depending on the type of acid generator used. ArF excimer laser (wavelength 193 nm) or Far ultraviolet rays typified by a KrF excimer laser (wavelength 248 nm) are preferable, and an ArF excimer laser (wavelength 193 nm) is particularly preferable.
Moreover, exposure conditions, such as exposure amount, are suitably selected according to the compounding composition of a radiation sensitive resin composition, the kind of additive, etc. In the method for forming a photoresist pattern using the radiation-sensitive resin composition of the present invention, it is preferable to perform heat treatment (post-exposure bake: PEB) after exposure. By PEB, the dissociation reaction of the acid dissociable group in the resin component proceeds smoothly. Although the heating conditions for this PEB vary depending on the composition of the radiation sensitive resin composition, it is preferably 30 to 200 ° C, more preferably 50 to 170 ° C.

  In the step (3), the exposed photoresist film is developed to form a predetermined photoresist pattern. Examples of the developer used for this development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propyl. Amine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo -An alkaline aqueous solution in which at least one of alkaline compounds such as [4.3.0] -5-nonene is dissolved is preferable. The concentration of the alkaline aqueous solution is preferably 10% by mass or less. For example, if the concentration of the alkaline aqueous solution exceeds 10% by mass, the unexposed area may be dissolved in the developer, which is not preferable.

Further, for example, an organic solvent may be added to the developer using the alkaline aqueous solution described above. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methyl alcohol, ethyl alcohol, and n-propyl. Alcohols such as alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane Esters such as ethyl acetate, n-butyl acetate and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone and dimethylformamide. These organic solvents can be used alone or in admixture of two or more.
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. In this case, when the ratio 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 can be added to the developer composed of the alkaline aqueous solution. In addition, after developing with the developing solution which consists of alkaline aqueous solution, generally it wash | cleans with water and dries.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.
[Mw, Mn, and Mw / Mn]:
Using Tosoh GPC columns (trade name “G2000HXL”, 2 trade names “G3000HXL”, trade name “G4000HXL” 1), 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 components]:
Using the trade name “Intersil ODS-25 μm column” (4.6 mmφ × 250 mm) manufactured by GL Sciences Inc., under the analysis conditions of flow rate: 1.0 ml / min, elution solvent: acrylonitrile / 0.1% phosphoric acid aqueous solution , Measured by high performance liquid chromatography (HPLC). The low molecular weight component is a component mainly composed of a monomer, more specifically a component having a molecular weight of less than 1,000, preferably a component having a molecular weight equal to or less than that of the trimer.

[Sensitivity (1)]:
First, using a trade name “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Co., Ltd.), an underlayer antireflection film (trade name “ARC29A”, produced by Brewer Science Co., Ltd.) having a thickness of 77 nm is formed on the surface of an 8-inch silicon wafer. And used as a substrate.
Thereafter, the radiation-sensitive resin composition prepared in each Example and Comparative Example was spin-coated on the substrate under the trade name “CLEAN TRACK ACT8” and baked (PB) under the conditions shown in Table 3. As a result, a resist film having a thickness of 120 nm was formed. Next, the resist film was exposed through the mask pattern using an ArF excimer laser exposure apparatus (trade name “NSR S306C”, manufactured by Nikon, illumination condition: NA 0.78 sigma 0.93 / 0.69). Then, after baking (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 form a positive resist pattern. 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. The optimum exposure amount was evaluated as sensitivity (shown as “sensitivity (1) (mJ / cm ² )” in Table 4). A scanning electron microscope (trade name “S-9380”, manufactured by Hitachi High-Technologies Corporation) was used to measure the line width and the distance between the lines.

[Resolution (1)]:
Among the line widths of the line-and-space resist patterns formed in the evaluation of sensitivity (1), the minimum line width (nm) of the lines was used as an evaluation value of resolution (in Table 4, “Resolution (1) ( nm) ”). The smaller the numerical value, the better the resolution.
[Cross sectional shape (1)]:
The cross-sectional shape of the 90 nm line and space pattern of the resist film obtained by the evaluation of sensitivity (1) above was observed with a scanning electron microscope (trade name “S-4800”) manufactured by Hitachi High-Technologies Corporation. The line width Lb in the middle of the film and the line width La in the upper part of the film were measured. As a result of the measurement, the case where the value calculated by (La−Lb) / Lb is within the range of 0.9 ≦ (La / Lb) ≦ 1.1 is defined as “good”, and the case where the value is out of the range is represented by “ “Bad”.

[PEB temperature dependence]:
Observation of a 90 nm line-and-space pattern resolved at the optimum exposure for evaluation of sensitivity (1) above, using a scanning electron microscope (trade name “S-9380”, manufactured by Hitachi High-Technologies Corporation) Regarding the line width when observed from above, the difference between the line width when PEB is performed under the conditions shown in Table 3 and the line width at the optimum exposure amount when the PEB temperature is changed by ± 2 ° C. The amount of change when measured and divided by the temperature difference was defined as PEB temperature dependency (nm / ° C.). The case where the PEB temperature dependency was less than 3 nm / ° C. was determined as “good”, and the case where it was 3 nm / ° C. or higher was determined as “bad”.
[LWR (Line Roughness Characteristics)]:
In observation of a 90 nm line and space pattern resolved at the optimum exposure dose for the sensitivity (1) evaluation, the pattern was measured with a scanning electron microscope (trade name “S-9380”, manufactured by Hitachi High-Technologies Corporation). When observed from above, the line width was observed at an arbitrary point, and the measurement variation was evaluated at 3σ (nm).
[Minimum dimensions before collapse]:
In the observation of a 90 nm line and space pattern resolved at the optimum exposure amount for the sensitivity (1) evaluation, when exposure is performed at an exposure amount larger than the optimum exposure amount, a pattern line is obtained. Since the width becomes narrower, the resist pattern eventually collapses. The line width at the maximum exposure amount at which the resist pattern is not confirmed to be collapsed is defined as the dimension (nm) before the minimum collapse, and is used as an index of pattern collapse resistance. The smaller the line width, the better. In addition, the measurement before the minimum collapse (nm) used the scanning electron microscope (Brand name "S-9380", Hitachi High-Technologies company make).
[Blob defect]:
First, using a trade name “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Co., Ltd.), 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 above sensitivity is applied to the resist film through an rubbed glass on which no mask pattern is formed by an ArF excimer laser exposure apparatus (trade name “NSR S306C”, manufactured by Nikon, illumination condition: NA 0.78 sigma 0.85). The exposure was performed at the optimum exposure amount in (1). Next, after performing PEB under the conditions shown in Table 3, development with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 30 seconds, washing with water, and drying to evaluate blob defects (blob defects) A substrate was made.
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.

[Sensitivity (2)]:
First, using a trade name “CLEAN TRACK ACT12” (manufactured by Tokyo Electron), an underlayer antireflection film (trade name “ARC29A”, produced by Brewer Science) with a film thickness of 77 nm is formed on the surface of an 8-inch silicon wafer. And used as a substrate.
Thereafter, the radiation-sensitive resin composition is spin-coated on the substrate under the trade name “CLEAN TRACK ACT12” and baked (PB) under the conditions shown in Table 3 to form a resist film having a thickness of 100 nm. Formed. Furthermore, regarding a specific radiation sensitive resin composition (the radiation sensitive resin compositions of Examples 6 and 7), a trade name “NFC TCX041” (trade name “CLEAN TRACK ACT12”) is formed on this resist film. JSR Co.) was spin-coated and baked at 90 ° C./60 seconds to form a 90 nm immersion protective film. Next, the resist film was exposed through the mask pattern using an ArF excimer laser immersion exposure apparatus (trade name “Nikon S610C”, manufactured by Nikon) with NA = 1.30, σ0 / σ1 = 0.895, and CrossPole. At this time, pure water was used as an immersion solvent between the resist upper surface and the immersion exposure machine lens. Then, after baking (PEB) under the conditions shown in Table 3, the resist was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds, washed with water, and dried. A pattern was formed.
In the obtained resist film, an exposure dose (mJ / cm ² ) when a resist pattern having a line width of 48 nm and a distance between the lines of 48 nm (line and space is 1: 1) is formed. ) Was the optimum exposure. This optimum exposure amount was evaluated as sensitivity (shown as “sensitivity (2) (mJ / cm ² )” in Table 5). A scanning electron microscope (trade name “CG-4000”, manufactured by Hitachi High-Technologies Corporation) was used to measure the line width and the distance between the lines.
[Resolution (2)]:
Among the line widths of the line-and-space resist pattern formed in the evaluation of the sensitivity (2), the minimum line width (nm) of the lines was used as an evaluation value of resolution (in Table 5, “Resolution (2) ( nm) ”). The smaller the numerical value, the better the resolution.
[LWR (2)]:
In observation of a 48 nm line and space pattern resolved at the optimum exposure dose for the sensitivity (2) evaluation, the pattern was measured with a scanning electron microscope (trade name “CG-4000”, manufactured by Hitachi High-Technologies Corporation). When observed from above, the line width was observed at an arbitrary point, and the measurement variation was evaluated at 3σ (nm).

Polymer synthesis:
The polymer was synthesize | combined using the compounds (M-1)-(M-8) shown in Table 1 in each Example. Compounds (M-1) to (M-8) are represented by the following formulas (M-1) to (M-8).

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

This copolymer has Mw of 6930, Mw / Mn of 1.61, and as a result of ¹³ C-NMR analysis, each of the repeating units derived from the compound (M-1) and the compound (M-2) The content rate was 50.9: 49.1 (mol%). Moreover, 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 Examples 2 to 7 and Polymer Comparative Example 1: Resins (A-2) to (A-8)
Resins (A-2) to (A-8) were synthesized in the same manner as in Example 1 except that the formulation shown in Table 1 was used.
Moreover, about the obtained resin (A-1)-(A-8), the ratio (mol%) of each repeating unit by ¹³ C-NMR analysis, a yield (%), Mw, dispersity (Mw / Mn) ) And the measurement results of the residual ratio (mass%) of the low molecular weight component are shown in Table 2.

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 (radiation sensitive acid generator (B) which comprises radiation sensitive resin compositions other than resin (A-1)-(A-8) synthesize | combined in the said polymer Example and comparative example, The nitrogen-containing compound (C), additive (D) and solvent (E)) are shown below.

Radiation sensitive acid generator (B):
(B-1): 4-cyclohexylphenyl diphenylsulfonium nonafluoro-n-butanesulfonate (B-2): triphenylsulfonium nonafluoro-n-butanesulfonate (B-3): 1- (4-n-butoxy Naphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate (B-4): 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2- (bicyclo [2.2 .1] Hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate (B-5): triphenylsulfonium 2- (bicyclo [2.2.1] hept-2-yl)- 1,1,2,2-tetrafluoroethane sulfonate (B-6): triphenylsulfonium 2- (bicyclo [2. .1] hept-2-yl) -1,1-difluoroethanesulfonate

Nitrogen-containing compound (C):
(C-1): Nt-butoxycarbonyl-4-hydroxypiperidine (C-2): R-(+)-(tert-butoxycarbonyl) -2-piperidinemethanol (C-3): Nt- Butoxycarbonylpyrrolidine (C-4): Nt-butoxycarbonyl-2-phenylbenzimidazole

Additive (D):
(D-1): Lithocholic acid t-butoxycarbonylmethyl (D-2): Copolymer of methacrylic acid 2,2,2-trifluoroethyl ester and methacrylic acid 1-ethylcyclohexyl ester (2,2 methacrylate) , 2-trifluoroethyl ester and methacrylic acid 1-ethylcyclohexyl ester charge molar ratio is 30:70, final composition ratio is 29.5: 70.5, Mw is 7300, Mw / Mn is 1.60)

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

Composition Example 1
8. 100 parts by mass of the resin (A-1) obtained in Polymer Example 1, 4-cyclohexylphenyl / diphenylsulfonium / nonafluoro-n-butanesulfonate (B-1) as a radiation sensitive acid generator (B) 6 parts by mass, 1.05 parts by mass of Nt-butoxycarbonyl-4-hydroxypiperidine (C-1) as a nitrogen-containing compound (C) are mixed, and propylene glycol monomethyl ether acetate as a solvent (E) is mixed with this mixture (E-1) 1400 parts by mass and 600 parts by mass of cyclohexanone (E-2) are added, the above mixture is dissolved to obtain a mixed solution, and the obtained mixed solution is filtered through a filter having a pore size of 0.20 μm. A radiation sensitive resin composition was prepared. Table 3 shows the formulation of the radiation sensitive resin composition.

  About the radiation sensitive resin composition of the obtained composition Example 1, the sensitivity (1), resolution (1), pattern cross-sectional shape (1), PEB temperature dependency, LWR (line roughness characteristic), The minimum pre-collapse dimensions and blob defects were evaluated. The evaluation results are shown in Table 4.

Composition Examples 2-9 and Composition Comparative Example 1
A radiation-sensitive resin composition (Composition Examples 2 to 9 and Composition) was carried out in the same manner as Composition Example 1, except that each component for preparing the radiation-sensitive resin composition was changed as shown in Table 3. Comparative Example 1) was obtained. About the radiation sensitive resin composition of obtained composition Examples 2-9 and composition comparative example 1, the sensitivity (1), the resolution (1), the cross-sectional shape (1) of a pattern, and PEB temperature dependence mentioned above. , LWR (line roughness characteristics), minimum pre-collapse dimensions, and blob defects were evaluated. The evaluation results are shown in Table 4.

  Moreover, about the radiation sensitive resin composition of composition Examples 6-9, about the sensitivity (2), resolution (2), cross-sectional shape (2) of a pattern using a liquid immersion exposure, a watermark defect, and a bubble defect Evaluation was performed. The evaluation results are shown in Table 5.

  As is clear from Tables 4 and 5, the compound (M-1) to be the repeating unit (A1) represented by the above formula (1), the repeating unit (A2) represented by the above formula (2), and A radiation-sensitive resin composition using a polymer having at least one of compounds (M-2), (M-3), (M-6) and (M-7) as a resin (A) ( Composition Examples 1 to 9) were found to improve not only the resolution but also various resist performances such as LWR and PEB temperature dependency when a resist pattern was formed.

  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 small LWR, good PEB temperature dependency, excellent pattern collapse resistance, and excellent defectability.

Claims (3)

A polymer comprising a repeating unit (A1) represented by the following formula (1) and a repeating unit (A2) represented by the following formula (2), 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, and m represents an integer of 1 to ^3. R ³ represents carbon. (The alkyl group of the number 1-4 is represented, and n represents the integer of 1-5.) The polymer further includes at least one repeating unit (A3) selected from a repeating unit represented by the following formula (3-1) and a repeating unit represented by the following formula (3-2). The polymer according to claim 1.

(In Formula (3-1) and Formula (3-2), R ⁴ independently represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁵ represents an alkyl group having 1 to 4 carbon atoms. And R ⁶ independently represents an alkyl group having 1 to 4 carbon atoms.) A radiation-sensitive resin composition comprising a resin (A) and a radiation-sensitive acid generator (B),
The radiation-sensitive resin composition, wherein the resin (A) is a resin containing the polymer according to claim 1 or 2.