JP2009286870A - New polymeric compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new polymeric compound usable for lithographic application. <P>SOLUTION: The polymeric compound has a constituent unit (a0) represented by general formula (a0-1) [wherein, R<SP>1</SP>is a hydrogen atom, a 1C-5C alkyl group or a 1C-5C fluorinated alkyl group; R<SP>2</SP>and R<SP>3</SP>are each independently a hydrogen atom or an alkyl group which may contain an oxygen atom at an optional position, or form an alkylene group by bonding to each other; and W is a cyclic alkylene group which may contain an oxygen atom at an optional position]. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a novel polymer compound that can be used for lithography.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to radiation such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film.
A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has rapidly progressed due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. In addition, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.

Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions.
As a resist material satisfying such requirements, a chemically amplified resist containing a base material component whose solubility in an alkaline developer is changed by the action of an acid and an acid generator that generates an acid upon exposure is used. . Resin (base resin) is mainly used as the base component of the chemically amplified resist.
For example, a positive chemically amplified resist contains, as a base resin, a resin whose solubility in an alkaline developer is increased by the action of an acid. When a resist pattern is formed, an acid is generated from an acid generator by exposure. The solubility of the base resin in an alkaline developer is increased by the action of the acid (see, for example, Patent Document 1).
Moreover, as a negative chemically amplified resist, a base resin that contains a possible resin (alkali-soluble resin) in an alkaline developer and further contains a crosslinking agent is generally used. In such a resist composition, when an acid is generated from an acid generator upon exposure at the time of forming a resist pattern, the base resin and the crosslinking agent react due to the action of the acid, and the solubility of the base resin in an alkaline developer decreases. (For example, refer nonpatent literature 1-2.).
Currently, as a resist base resin used in ArF excimer laser lithography and the like, a resin having a structural unit derived from (meth) acrylic acid ester in the main chain (acrylic resin) is excellent in transparency near a wavelength of 193 nm. Resin) is mainly used. Here, “(meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position. “(Meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position.
JP 2003-241385 A SPIE Advances in Resist Technology and Processing XIV, Vol. 3333, p417-424 (1998) SPIE Advances in Resist technology and Processing XIX, Vol. 4690 p94-100 (2002)

In the future, as further progress in lithography technology and expansion of application fields are expected, there is an increasing demand for new materials that can be used for lithography applications.
This invention is made | formed in view of the said situation, Comprising: It aims at providing the novel high molecular compound which can be used for a lithography use.

In order to solve the above-mentioned problems, the present inventors provide the following means.
That is, this invention is a high molecular compound which has a structural unit (a0) represented by the following general formula (a0-1).

［式（ａ０−１）中、Ｒ^１は水素原子、炭素数１〜５のアルキル基または炭素数１〜５のフッ素化アルキル基を表し、Ｒ^２およびＲ^３は、それぞれ独立して水素原子または任意の位置に酸素原子を含んでいてもよいアルキル基を表すか、または両者が結合してアルキレン基を表し、Ｗは任意の位置に酸素原子を含んでいてもよい環状のアルキレン基を表す。］

[In Formula (a0-1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and R ² and R ³ are each independently a hydrogen atom. Or, it represents an alkyl group which may contain an oxygen atom at any position, or they are bonded to each other to represent an alkylene group, and W represents a cyclic alkylene group which may contain an oxygen atom at any position. . ]

In the present specification and claims, the “structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
The “structural unit derived from an acrylate ester” means a structural unit constituted by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include not only acrylic acid esters in which a hydrogen atom is bonded to the α-position carbon atom, but also those in which a substituent (an atom or group other than a hydrogen atom) is bonded to the α-position carbon atom. Include concepts. Examples of the substituent include a lower alkyl group, a halogenated lower alkyl group, and a hydroxyalkyl group.
The α-position (α-position carbon atom) of a structural unit derived from an acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.
“Exposure” is a concept that includes general irradiation of radiation.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the “alkoxycarbonyl group”.
A “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.
“Aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
The “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
The “hydroxyalkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a hydroxyl group.

  The present invention can provide a novel polymer compound that can be used for lithography.

≪Polymer compound≫
[Structural unit (a0)]
The polymer compound of the present invention (hereinafter referred to as polymer compound (A1)) has the structural unit (a0) represented by the general formula (a0-1).
As the alkyl group having 1 to 5 carbon atoms in R ¹ , a linear or branched alkyl group is preferable. For example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert- Examples thereof include a butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
As the fluorinated alkyl group having 1 to 5 carbon atoms in R ¹ , a linear or branched fluorinated alkyl group is preferable, and examples thereof include a monofluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and perfluoroethyl. Group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluoroisobutyl group, perfluoro-tert-butyl group, perfluoropentyl group, perfluoroisopentyl group, perfluoroneopentyl group and the like. .
R ¹ is preferably a hydrogen atom, a methyl group or a trifluoromethyl group, more preferably a hydrogen atom or a methyl group, from the viewpoint of industrial availability.

The alkyl group for R ² and R ³ may be linear, branched or cyclic. Among these, the linear or branched alkyl group in R ² and R ³ may have a cyclic alkyl group as a substituent. In addition, the cyclic alkyl group in R ² and R ³ includes, as a substituent, a linear or branched alkyl group, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, It may have an oxygen atom (= O) or the like.
As the linear or branched alkyl group, an alkyl group having 1 to 5 carbon atoms is preferable. For example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, or an i-butyl group. , T-butyl group, 2-methyl-2-butyl group, 3-methyl-2-butyl group, 1-pentyl group, 2-pentyl group, 3-pentyl group and the like. The linear or branched alkyl group may have a cyclic alkyl group as a substituent.
Examples of the cyclic alkyl group include cyclopropyl group, cyclobutyl group, cyclopentyl group, 1-methyl-1-cyclopentyl group, 1-ethyl-1-cyclopentyl group, cyclohexyl group, 1-methyl-1-cyclopentyl group, 1- Ethyl-1-cyclopentyl group, 1-methyl-1-cyclohexyl group, 1-ethyl-1-cyclohexyl group, 1-methyl-1-cycloheptyl group, 1-ethyl-1-cycloheptyl group, 1-methyl-1 -Cyclooctyl group, 1-ethyl-1-cyclooctyl group, bicyclo [2.2.1] hept-2-yl group, 1-adamantyl group, 2-adamantyl group, 2-methyl-2-adamantyl group, 2 -Ethyl-2-adamantyl group and the like.
The alkyl group in R ² and R ³ may contain an oxygen atom at any position. That an alkyl group contains an oxygen atom indicates that an oxygen atom (—O—) is introduced at an arbitrary position in the carbon chain of the alkyl group. Examples of the alkyl group containing an oxygen atom include an acetal type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group described later.
The alkylene group represented by the combination of R ² and R ³ is preferably a linear or branched alkylene group, and more preferably a linear alkylene group. The alkylene group preferably has 1 to 5 carbon atoms, and examples thereof include an ethanediyl group, a propane-1,3-diyl group, and a butane-1,4-diyl group.

When the polymer compound (A1) of the present invention is used as a base component of the negative resist composition, at least one of R ² and R ³ (e.g. R ²⁾ is preferably a hydrogen atom, R ² and More preferably, both R ³ are hydrogen atoms.
When the polymer compound (A1) of the present invention is used as a base component of a positive resist composition, at least one of R ² and R ³ is an alkyl group that may contain an oxygen atom at an arbitrary position. In addition, the alkyl group is preferably an acid dissociable, dissolution inhibiting group. In this case, specific examples of the structural unit (a0) include structural units represented by general formula (a0-1-4) shown below.

［式（ａ０−１−４）中、Ｒ^１、Ｒ^２、Ｗはそれぞれ上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｗと同じであり、Ｚ^１は酸解離性溶解抑制基である。］

Wherein ^{(a0-1-4), R 1, R} 2, W are each the same as ^{R 1, R} 2, W in the above formula (a0-1), ^{Z 1} represents an acid dissociable, dissolution inhibiting group It is. ]

The “acid dissociable, dissolution inhibiting group” has an alkali dissolution inhibiting property that makes the entire polymer compound (A1) insoluble in an alkaline developer before dissociation when forming a resist pattern as a resist composition. At the same time, the polymer is dissociated by the action of an acid generated from the acid generator component blended in the resist composition by exposure to increase the solubility of the entire polymer compound (A1) in an alkaline developer.
The acid dissociable, dissolution inhibiting group in the structural unit (a0) is not particularly limited as long as it corresponds to an alkyl group that may contain an oxygen atom at an arbitrary position. Conventionally, a positive chemically amplified resist It can be appropriately selected from those proposed for the base material component of the composition. As such acid dissociable, dissolution inhibiting groups, acetal acid dissociable, dissolution inhibiting groups such as tertiary alkyl groups and alkoxyalkyl groups are widely known.
The tertiary alkyl group is an alkyl group having a tertiary carbon atom, and when at least one of R ² and R ³ of the structural unit (a0) is a tertiary alkyl group, the tertiary alkyl group A tertiary carbon atom is bonded to the nitrogen atom at the terminal of the sulfamoyloxy group (OSO ₂ N group). In this tertiary alkyl group, when an acid generated from an acid generator component by exposure acts when forming a resist pattern as a resist composition, the nitrogen at the terminal of the sulfamoyloxy group (OSO ₂ N group) The bond is broken between the atom and the tertiary carbon atom.
Examples of the tertiary alkyl group include a branched tertiary alkyl group and a tertiary alkyl group containing an aliphatic cyclic group.
Examples of the branched tertiary alkyl group include a group represented by -C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ). ^Wherein, R 71 ^{to R 73} each independently represents a linear alkyl group of 1 to 5 carbon atoms. The group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ) preferably has 4 to 8 carbon atoms, specifically a tert-butyl group or a 2-methyl-2-butyl group. , 2-methyl-2-pentyl group, 3-methyl-3-pentyl group and the like. A tert-butyl group is particularly preferable.

The aliphatic cyclic group may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).
The aliphatic cyclic group may be a hydrocarbon group (alicyclic group) composed of carbon and hydrogen, and some of the carbon atoms constituting the ring of the alicyclic group are oxygen atoms, nitrogen atoms, sulfur. It may be a heterocyclic group substituted with a heteroatom such as an atom. As the aliphatic cyclic group, an alicyclic group is preferable.
The aliphatic cyclic group may be either saturated or unsaturated, but is preferably saturated because it is highly transparent to ArF excimer laser and the like, and has excellent resolution and depth of focus (DOF). .
The aliphatic cyclic group may be a monocyclic group or a polycyclic group, but is preferably a polycyclic group. Moreover, it is preferable that carbon number of an aliphatic cyclic group is 5-15.
Specific examples of monocyclic alicyclic groups include groups in which one or more hydrogen atoms have been removed from cycloalkane. More specifically, a group in which one or more hydrogen atoms have been removed from cyclopentane or cyclohexane can be mentioned, and a group in which two hydrogen atoms have been removed from cyclohexane is preferred.
Specific examples of the polycyclic alicyclic group include groups in which one or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane, or the like. More specifically, a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane can be used.
Of these, groups in which two hydrogen atoms have been removed from cyclohexane, adamantane, norbornane, and tetracyclododecane are preferred because they are easily available in the industry. Among these, a group obtained by removing two hydrogen atoms from adamantane or norbornane is particularly preferable.
Examples of the tertiary alkyl group containing an aliphatic cyclic group include: (i) a group having a tertiary carbon atom on the ring skeleton of the aliphatic cyclic group; (ii) an aliphatic cyclic group; And a group having a branched alkylene group having a tertiary carbon atom bonded thereto.
Specific examples of (i) include groups represented by the following general formulas (1-1) to (1-9).
Specific examples of (ii) include groups represented by the following general formulas (2-1) to (2-6).

［式中、Ｒ^１４はアルキル基であり、ｇは０〜８の整数である。］

[Wherein, R ¹⁴ represents an alkyl group, and g represents an integer of 0 to 8. ]

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立にアルキル基である。］

[Wherein, R ¹⁵ and R ¹⁶ each independently represents an alkyl group. ]

As the alkyl group for R ^{14 to} R ¹⁶ , a lower alkyl group is preferable, and a linear or branched alkyl group is preferable. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
g is preferably an integer of 0 to 5, more preferably an integer of 1 to 3, and still more preferably 1 or 2.
Among the above, specific examples of the formula (1-2) include, for example, 1-methyl-1-cyclobutyl group, 1-ethyl-1-cyclobutyl group, 1-isopropyl-1-cyclobutyl group, 1-methyl-1 -Cyclopentyl group, 1-ethyl-1-cyclopentyl group, 1-isopropyl-1-cyclopentyl group, 1-methyl-1-cyclohexyl group, 1-ethyl-1-cyclohexyl group, 1-isopropyl-1-cyclohexyl group, 1 -Methyl-1-cycloheptyl group, 1-ethyl-1-cycloheptyl group, 1-isopropyl-1-cycloheptyl group, 1-methyl-1-cyclooctyl group, 1-ethyl-1-cyclooctyl group, etc. Can be mentioned.

In R ² and R ³ of the structural unit (a0), the “acetal acid dissociable, dissolution inhibiting group” is bonded to the terminal nitrogen atom of the sulfamoyloxy group (OSO ₂ N group). In this acetal type acid dissociable, dissolution inhibiting group, when an acid is generated from an acid generator component by exposure when forming a resist pattern as a resist composition, this acid acts to react with the nitrogen atom and the acetal type acid dissociation property. The bond is cleaved with the dissolution inhibiting group.
Examples of the acetal type acid dissociable, dissolution inhibiting group include those similar to the acetal type acid dissociable, dissolution inhibiting group exemplified in the structural unit (a1) described later.

  The cyclic alkylene group which may have an oxygen atom at an arbitrary position represented by W may be a monocyclic group or a polycyclic group. The alkylene group preferably has 3 to 20 carbon atoms, more preferably 5 to 12 carbon atoms. Examples of the alkylene group include cyclopropanediyl group, cyclobuta-1,2-diyl group, cyclobuta-1,3-diyl group, cyclopenta-1,2-diyl group, cyclopenta-1,3-diyl group, cyclohexa -1,2-diyl group, cyclohexa-1,3-diyl group, cyclohexa-1,4-diyl group, bicyclo [2.2.1] hepta-2,3-diyl group, bicyclo [2.2.1] ] Hepta-2,5-diyl group, 7-oxabicyclo [2.2.1] hepta-2,5-diyl group, bicyclo [2.2.1] hepta-2,6-diyl group, 7-oxa Bicyclo [2.2.1] hepta-2,6-diyl group, adamanta-1,3-diyl group, adamanta-1,2-diyl group and the like can be mentioned.

More specifically, examples of the structural unit (a0) include structural units represented by the following formulas (a0-1-10) to (a0-1-72).
In the following formulae, Me represents a methyl group.

In the polymer compound (A1) of the present invention, as the structural unit (a0), one type of structural unit may be used alone, or two or more types may be used in combination.
Further, the polymer compound (A1) of the present invention may be a polymer consisting only of the structural unit (a0), a copolymer consisting of two or more structural units (a0), and It may be a copolymer containing other structural units.
When the polymer compound (A1) of the present invention is a copolymer containing other structural units other than the structural unit (a0), the proportion of the structural unit (a0) in the polymer compound (A1) 10-80 mol% is preferable with respect to all the structural units which comprise (A1), 15-80 mol% is more preferable, 20-70 mol% is further more preferable, and 20-60 mol% is the most preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

When the polymer compound (A1) of the present invention is a copolymer containing other structural units other than the structural unit (a0), examples of the other structural units include the following structural units (a1) and structural units ( a2), structural unit (a3), structural unit (a4), structural unit (a5), and the like. Further, examples of the structural unit (a3) include the following structural unit (a′3) and structural unit (a ″ 3).
Among these structural units, the structural unit combined with the structural unit (a0) in the copolymer is one of the structural units (a1) to (a5) depending on the use of the resist composition, desired characteristics, and the like. What is necessary is just to select suitably from the inside.
For example, when the resist composition is negative, the structural unit combined with the structural unit (a0) is preferably the structural unit (a3) and / or the structural unit (a4). The structural unit (a′3), structural unit At least one selected from the group consisting of the unit (a ″ 3) and the structural unit (a4) is more preferable, and the structural unit (a4) is more preferable.
In the case where the resist composition is positive, the structural unit combined with the structural unit (a0) may be any of the structural units (a1) to (a5). The structural unit (a1) and / or Or (a2) is preferred.

[Structural unit (a1)]
The structural unit (a1) is a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
The acid dissociable, dissolution inhibiting group in the structural unit (a1) is an alkali dissolution inhibitor that makes the entire polymer compound (A1) insoluble in an alkaline developer before dissociation when forming a resist pattern as a resist composition. It is dissociated by an acid generated by exposure from an acid generator component and increases the solubility of the entire polymer compound (A1) in an alkaline developer. What is proposed as an acid dissociable, dissolution inhibiting group for the base resin can be used. In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. .
Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O)). A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience.
Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include those similar to the tertiary alkyl group exemplified as the acid dissociable, dissolution inhibiting group in the structural unit (a0).

The “acetal-type acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, this acid acts to break the bond between the acetal acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal acid dissociable, dissolution inhibiting group is bonded.
Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または低級アルキル基を表し、ｎは０〜３の整数を表し、Ｙは低級アルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ ′ and R ² ′ each independently represents a hydrogen atom or a lower alkyl group, n represents an integer of 0 to 3, and Y represents a lower alkyl group or an aliphatic cyclic group. ]

In the above formula, n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the lower alkyl group for R ¹ ′ and R ² ′ include the same lower alkyl groups as those described above for R. A methyl group or an ethyl group is preferable, and a methyl group is most preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable, dissolution inhibiting group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同様である。］

Wherein, ^{R 1} ', n, Y are as defined above. ]

Examples of the lower alkyl group for Y include the same lower alkyl groups as those described above for R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable, dissolution inhibiting group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状または分岐鎖状のアルキル基または水素原子であり、Ｒ^１９は直鎖状、分岐鎖状または環状のアルキル基である。Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represent a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ represents a linear, branched or cyclic alkyl group. R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group. It is preferable that both R ¹⁷ and R ¹⁸ are hydrogen atoms, or one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group. In particular, both R ¹⁷ and R ¹⁸ are preferably hydrogen atoms.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group, are included. Examples include groups excluding hydrogen atoms. Specific examples thereof include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ^{19 and} the end of R ¹⁷ And may be combined.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4-7 membered ring, and more preferably a 4-6 membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  As the structural unit (a1), one or more selected from the group consisting of structural units represented by the following general formula (a1-0-1) and structural units represented by the following general formula (a1-0-2): Is preferably used.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^１は酸解離性溶解抑制基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; and X ¹ represents an acid dissociable, dissolution inhibiting group. ]

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^２は酸解離性溶解抑制基を示し；Ｙ^２はアルキレン基または脂肪族環式基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents an alkylene group or an aliphatic cyclic group. ]

In the general formula (a1-0-1), the lower alkyl group or halogenated lower alkyl group of R is exemplified as the lower alkyl group or halogenated lower alkyl group which may be bonded to the α-position of the acrylate ester. It is the same.
X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. it can.
In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).
Y ² is preferably an alkylene group having 1 to 4 carbon atoms or a divalent aliphatic cyclic group, and the aliphatic cyclic group is the above except that a group in which two or more hydrogen atoms are removed is used. The thing similar to description of an "aliphatic cyclic group" can be used.

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［上記式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５の低級アルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し；ｍは０または１を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５の低級アルキル基を表す。］

[In the above formula, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; M represents 0 or 1; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. ]

R ² ′ is preferably at least one hydrogen atom, more preferably both hydrogen atoms. n is preferably 0 or 1.
X ′ is the same as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group exemplified in X ¹ above.
Examples of the aliphatic cyclic group for Y include the same groups as those exemplified above in the description of “aliphatic cyclic group”.

  Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.

In the polymer compound (A1), as the structural unit (a1), one type of structural unit may be used, or two or more types may be used in combination.
Among these, the structural unit represented by the general formula (a1-1) is preferable, and specifically, (a1-1-1) to (a1-1-6) or (a1-1-35) to (a1- It is more preferable to use at least one selected from structural units represented by 1-41).
Furthermore, as the structural unit (a1), in particular, those represented by the following general formula (a1-1-01) including the structural units of the formula (a1-1-1) to the formula (a1-1-4) The following general formula (a1-1-02) including the structural units of formulas (a1-1-35) to (a1-1-41) is also preferable.

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１１は低級アルキル基を示す。）

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group.)

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１２は低級アルキル基を示す。ｈは１〜３の整数を表す）

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ¹² represents a lower alkyl group, and h represents an integer of 1 to 3)

In general formula (a1-1-01), R is the same as defined above. The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group.

In general formula (a1-1-02), R is the same as defined above. The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 or 2, and most preferably 2.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
When the polymer compound (A1) has the structural unit (a1), the proportion of the structural unit (a1) in the polymer compound (A1) is 5 to 5 with respect to all the structural units constituting the polymer compound (A1). 70 mol% is preferable, 20-70 mol% is more preferable, 25-55 mol% is further more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

[Structural unit (a2)]
The structural unit (a2) is a structural unit derived from an acrylate ester containing a lactone-containing cyclic group.
Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring, and when it is only the lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
The lactone cyclic group of the structural unit (a2) has an affinity for a developer containing water or a polymer compound (A1) when the polymer compound (A1) is used for forming a resist film. It is effective in enhancing the sex.
As the structural unit (a2), any unit can be used without any particular limitation.
Specifically, examples of the lactone-containing monocyclic group include groups in which one hydrogen atom has been removed from γ-butyrolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
More specifically, examples of the structural unit (a2) include structural units represented by general formulas (a2-1) to (a2-5) shown below.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基であり、Ｒ’は水素原子、低級アルキル基、または炭素数１〜５のアルコキシ基であり、ｍは０または１の整数であり、Ａ”は炭素数１〜５のアルキレン基または酸素原子である。］

[Wherein, R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ′ is a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms, and m is an integer of 0 or 1. And A ″ is an alkylene group having 1 to 5 carbon atoms or an oxygen atom.]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
The lower alkyl group for R ′ is the same as the lower alkyl group for R in the structural unit (a1).
Specific examples of the alkylene group having 1 to 5 carbon atoms of A ″ include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.
Below, the specific structural unit of the said general formula (a2-1)-(a2-5) is illustrated.

  Among these, it is preferable to use at least one selected from general formulas (a2-1) to (a2-5), and at least one selected from general formulas (a2-1) to (a2-3). It is preferable to use more than one species. Specifically, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-3-1), (a2-3) -2), at least one selected from (a2-3-9) and (a2-3-10) is preferably used.

As the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
When the polymer compound (A1) has the structural unit (a2), the proportion of the structural unit (a2) in the polymer compound (A1) is based on the total of all the structural units constituting the polymer compound (A1). 1-60 mol% is preferable, 10-55 mol% is more preferable, 20-55 mol% is further more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting the upper limit value or less, it is possible to balance with other structural units.

[Structural unit (a3)]
The structural unit (a3) is a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group, which does not correspond to the structural unit (a0).
By having the structural unit (a3), the hydrophilicity of the polymer compound (A1) increases, and when the polymer compound (A1) is used as a base component of the positive resist composition to form a positive resist pattern. Increases the affinity with the developer (alkaline aqueous solution), improves the alkali solubility in the exposed area, and contributes to the improvement of the resolution. Further, when forming a negative resist pattern using the polymer compound (A1) as a base component of the negative resist composition, in the case of constituent units (a′3) and (a ″ 3) described later. As explained, it can contribute to the improvement of cross-linking reactivity and residual film properties.
Examples of the polar group include a hydroxyl group, a hydroxyalkyl group, a cyano group, a carboxy group, a fluorinated hydroxyalkyl group (a hydroxyalkyl group in which a part of hydrogen atoms bonded to a carbon atom is substituted with a fluorine atom), and the like. A hydroxyl group and a hydroxyalkyl group are preferred.
Preferred examples of the structural unit (a3) include the following structural units (a′3) and (a ″ 3).

The structural unit (a′3) is a structural unit derived from an acrylate ester containing a hydroxyl group-containing aliphatic cyclic group. When the polymer compound (A1) is used as a base component of a negative resist composition, if it has a structural unit (a′3), the hydroxyl group (alcoholic hydroxyl group) of the structural unit (a′3) is blended together. It is preferable because it reacts with the crosslinker component by the action of the acid generated from the acid generator component, and the polymer compound (A1) is likely to change from a soluble property to an insoluble property in an alkaline developer. .
A “hydroxyl group-containing aliphatic cyclic group” is a group in which a hydroxyl group is bonded to an aliphatic cyclic group. The hydroxyl group may be directly bonded to the aliphatic ring or indirectly bonded as a hydroxyalkyloxy group.
The alkyl group in the hydroxyalkyloxy group is preferably linear or branched. The number of carbon atoms of the alkyl group is not particularly limited, but is preferably 2 to 5, more preferably 2 to 4, and most preferably 2 or 3.
The number of hydroxyl groups in the hydroxyalkyloxy group is not particularly limited, but is preferably 1 to 4, more preferably 1 to 3, and most preferably 1 or 2. The hydroxyl group is more preferably a primary hydroxyl group or a secondary hydroxyl group, and particularly preferably a primary hydroxyl group.
As the hydroxyalkyloxy group, a monohydroxyalkyloxy group and a dihydroxyalkyloxy group are preferable, and a monohydroxyethyl group, a monohydroxypropyl group, and a dihydroxypropyl group are more preferable.
The number of hydroxyl groups bonded to the aliphatic cyclic group is preferably 1 to 3, more preferably 1.
The aliphatic cyclic group may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).
An aliphatic cyclic group is a hydrocarbon group composed of carbon and hydrogen (alicyclic group), and a part of the carbon atoms constituting the ring of the alicyclic group is a heterogeneous group such as an oxygen atom, a nitrogen atom, or a sulfur atom. Heterocyclic groups and the like substituted with atoms are included. As the aliphatic cyclic group, an alicyclic group is preferable.
The aliphatic cyclic group may be either saturated or unsaturated, but is preferably saturated because it is highly transparent to ArF excimer laser and the like, and has excellent resolution and depth of focus (DOF). .
The aliphatic cyclic group may be a monocyclic group or a polycyclic group, but is preferably a polycyclic group. Moreover, it is preferable that carbon number of an aliphatic cyclic group is 5-15.
Specific examples of the aliphatic cyclic group (the state before the hydroxyl group is bonded) include the following.
That is, examples of the monocyclic group include groups in which two or more hydrogen atoms have been removed from a cycloalkane. More specifically, a group in which two or more hydrogen atoms have been removed from cyclopentane or cyclohexane can be mentioned, and a group in which two hydrogen atoms have been removed from cyclohexane is preferred.
Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane, or the like. More specifically, a group in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.
Of these, groups in which two hydrogen atoms have been removed from cyclohexane, adamantane, norbornane, and tetracyclododecane are preferred because they are easily available in the industry. Among these, a group obtained by removing two hydrogen atoms from adamantane or norbornane is particularly preferable.
In the structural unit (a′3), the hydroxyl group-containing aliphatic cyclic group is preferably bonded to the terminal oxygen atom of the carbonyloxy group [—C (O) —O—] of the acrylate ester.
Specific preferred examples of the structural unit (a′3) include structural units represented by general formula (a′3-1) shown below.

［式中、Ｒは前記と同じであり、Ｒ^４水素原子またはヒドロキシアルキル基であり、ｊは１〜３の整数である。］

[Wherein, R is the same as defined above, R ^{4 is a} hydrogen atom or a hydroxyalkyl group, and j is an integer of 1 to 3. ]

In the general formula (a′3-1), R is the same as described for R in the general formula (a1-0-1).
R ⁴ is a hydrogen atom or a hydroxyalkyl group.
The alkyl group in the hydroxyalkyl group for R ⁴ is preferably linear or branched. The number of carbon atoms of the alkyl group is not particularly limited, but is preferably 2 to 5, more preferably 2 to 4, and most preferably 2 or 3.
The number of hydroxyl groups in the hydroxyalkyl group of R ⁴ is not particularly limited, but is preferably 1 to 4, more preferably 1 to 3, and most preferably 1 or 2. The hydroxyl group is more preferably a primary hydroxyl group or a secondary hydroxyl group, and particularly preferably a primary hydroxyl group.
In the present invention, R ⁴ is preferably a monohydroxyalkyl group, a dihydroxyalkyl group or a hydrogen atom, more preferably a monohydroxyethyl group, a monohydroxypropyl group, a dihydroxypropyl group or a hydrogen atom.
j is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that OR ⁴ is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that OR ⁴ is bonded to the 3rd position of the adamantyl group.
j is preferably 1, particularly preferably one in which OR ⁴ is bonded to the 3-position of the adamantyl group. That is, the structural unit (a′3) is preferably a structural unit represented by the following general formula (a′3-11).

The structural unit (a ″ 3) is a structural unit that does not have a cyclic structure and is derived from acrylic acid having an alcoholic hydroxyl group in the side chain. The polymer compound (A1) is formed from a negative resist composition. When the structural unit (a ″ 3) is used as a base component, the hydroxyl group (alcoholic hydroxyl group) of the structural unit (a ″ 3) is caused by the action of an acid generated from the acid generator component blended together. Therefore, the polymer compound (A1) is likely to change from a soluble property to an insoluble property with respect to an alkaline developer, and an effect of improving the resolution can be obtained. Is it possible to obtain effects such as good controllability of the crosslinking reaction at the time of pattern formation, tending to improve the film density, and tending to improve heat resistance, and further improving etching resistance? Preferred.
“Having no cyclic structure” means having no aliphatic cyclic group or aromatic group. The structural unit (a ″ 3) is clearly distinguished from the structural unit (a′3) by not having a cyclic structure.
Examples of the structural unit having an alcoholic hydroxyl group in the side chain include a structural unit having a hydroxyalkyl group.
In the hydroxyalkyl group, the alkyl group is preferably linear or branched. Although carbon number of the said alkyl group is not specifically limited, 1-20 are preferable, 1-16 are more preferable, and it is most preferable that it is 1-12. The number of hydroxyl groups is not particularly limited, but is preferably 1 or 2, and more preferably 1.
For example, the hydroxyalkyl group may be directly bonded to the α-position carbon atom of the main chain (the portion where the ethylenic double bond of acrylic acid is cleaved), or may be substituted with the hydrogen atom of the carboxy group of acrylic acid. You may comprise ester. In the structural unit (a ″ 3), it is preferable that at least one or both of them have a hydroxyalkyl group.
When a hydroxyalkyl group is not bonded to the α-position, an alkyl group or a halogenated alkyl group may be bonded to the α-position carbon atom instead of a hydrogen atom. About these, Preferably, it is the same as that of description about R in the said general formula (a1-0-1).
As the structural unit (a ″ 3), structural units represented by general formula (a ″ 3-1) shown below are preferred.

［式中、Ｒ^５は水素原子、アルキル基、ハロゲン化アルキル基またはヒドロキシアルキル基であり；Ｒ^６はアルキル基またはヒドロキシアルキル基である。ただし、Ｒ^５、Ｒ^６の少なくとも一方はヒドロキシアルキル基である。］

[Wherein R ⁵ represents a hydrogen atom, an alkyl group, a halogenated alkyl group or a hydroxyalkyl group; R ⁶ represents an alkyl group or a hydroxyalkyl group. However, at least one of R ⁵ and R ⁶ is a hydroxyalkyl group. ]

In the formula (a ″ 3-1), R ⁵ represents a hydrogen atom, an alkyl group, a halogenated alkyl group, or a hydroxyalkyl group.
The hydroxyalkyl group for R ⁵ is preferably a linear or branched hydroxyalkyl group having 10 or less carbon atoms, more preferably a linear or branched hydroxyalkyl group having 1 to 8 carbon atoms. It is. The number of hydroxyl groups in the hydroxyalkyl group is not particularly limited, but is usually one. Further, the hydroxyl group is more preferably a primary or secondary hydroxyl group, particularly preferably a primary hydroxyl group. The hydroxyalkyl group for R ⁵ is most preferably a hydroxymethyl group or a hydroxyethyl group.
The alkyl group in R ⁵ is preferably an alkyl group having 10 or less carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, and most preferably an ethyl group or a methyl group.
The halogenated alkyl group for R ⁵ is preferably a lower alkyl group having 5 or less carbon atoms (preferably an ethyl group or a methyl group), and part or all of the hydrogen atoms are substituted with halogen atoms (preferably fluorine atoms). Group.
R ⁶ is an alkyl group or a hydroxyalkyl group.
As the alkyl group for R ^6, the same alkyl groups as those for R ⁵ can be used.
The hydroxyalkyl group for R ⁶ is preferably a linear or branched hydroxyalkyl group having 10 or less carbon atoms, more preferably a linear or branched hydroxyalkyl group having 2 to 8 carbon atoms. And most preferably a hydroxyethyl group. The number of hydroxyl groups in the hydroxyalkyl group is not particularly limited, but is usually one. Further, the hydroxyl group is more preferably a primary or secondary hydroxyl group, particularly preferably a primary hydroxyl group.
In the general formula (a ″ 3-1), at least one of R ⁵ and R ⁶ is a hydroxyalkyl group.

Among these (a ″ 3-1), from the viewpoint of improving the film density, (a ″ 3-1) in which R ⁵ is a hydroxyalkyl group and R ⁶ is an alkyl group is preferable. A structural unit derived from-(hydroxymethyl) acrylic acid ethyl ester or α- (hydroxymethyl) acrylic acid methyl ester is preferred.
Further, from the viewpoint of crosslinking efficiency, (a ″ 3-1) in which R ⁵ is an alkyl group and R ⁶ is a hydroxyalkyl group is preferable. Among them, a structure derived from (meth) acrylic acid hydroxyethyl ester Units are more preferred.

  In addition to the structural units (a′3) and (a ″ 3), the structural unit (a3) is preferably a structural unit represented by the following formula (a3-2), the following formula (a3-3). ) And the like.

［式中、Ｒは前記に同じであり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。］

[Wherein, R is the same as defined above, k is an integer of 1 to 3, t ′ is an integer of 1 to 3, l is an integer of 1 to 5, and s is an integer of 1 to 3] It is. ]

In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. These preferably have a 2-norbornyl group or a 3-norbornyl group bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

In the polymer compound (A1), as the structural unit (a3), one type of structural unit may be used alone, or two or more types may be used in combination.
In the present invention, it is particularly preferable that the structural unit (a3) has a structural unit derived from an acrylate ester containing a hydroxyl group, such as the structural units (a′3) and (a ″ 3).
When the polymer compound (A1) is used as a base component of the positive resist composition and the polymer compound (A1) contains the structural unit (a3), the structural unit (a3) in the polymer compound (A1) ) Is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, and even more preferably 5 to 25 mol% with respect to all structural units constituting the polymer compound (A1).
When the polymer compound (A1) is used as a base component of the positive resist composition and the polymer compound (A1) contains the structural unit (a3), the structural unit (a3) It is preferable to have (a′3), more preferably R ⁴ in the general formula (a′3-1) has a structural unit that is a hydrogen atom, and R in the general formula (a′3-11). More preferably, ⁴ has a structural unit which is a hydrogen atom.

When the polymer compound (A1) is used as a base component of the negative resist composition and the polymer compound (A1) contains the structural unit (a3), the structural unit (a3) in the polymer compound (A1) ) Is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, and even more preferably 25 to 65 mol% with respect to all the structural units constituting the polymer compound (A1).
When the polymer compound (A1) is used as a base component of a negative resist composition and the polymer compound (A1) contains the structural unit (a3), the structural unit (a3) It is preferable to have (a′3) and / or the structural unit (a ″ 3).
In this case, the polymer compound (A1) may have only one of the structural unit (a′3) and the structural unit (a ″ 3), or may have both.
As the structural unit (a′3) and the structural unit (a ″ 3), one type may be used alone, or two or more types may be used in combination.
In this case, the proportion of the structural unit (a′3) in the polymer compound (A1) is preferably 5 to 80 mol% with respect to the total of all the structural units constituting the polymer compound (A1). 10 to 70 mol% is more preferable, and 20 to 65 mol% is more preferable. The effect by containing a structural unit (a'3) is acquired by being more than the lower limit of the said range, and a balance with another structural unit is favorable by being below an upper limit.
The proportion of the structural unit (a ″ 3) in the polymer compound (A1) is preferably 5 to 50 mol% with respect to the total of all the structural units constituting the polymer compound (A1). The content is more preferably 5 to 40 mol%, particularly preferably 5 to 30 mol%, most preferably 10 to 25 mol%, and the structural unit (a The effect by containing "3" is acquired, and the balance with another structural unit is favorable because it is below an upper limit.

[Structural unit (a4)]
The structural unit (a4) is a structural unit derived from a non-acid-dissociable acrylic acid cyclic alkyl ester. Here, “non-acid dissociable” means that when an acid is generated from an acid generator component by exposure, the cyclic alkyl group does not dissociate from the structural unit even when the acid acts. .
Examples of the cyclic alkyl group in the structural unit (a4) include those similar to the alicyclic groups exemplified in the case of the structural unit (a0). For the ArF excimer laser and the KrF excimer laser ( A number of hitherto known materials can be used as the resin component of the resist composition (preferably for ArF excimer laser).
The cyclic alkyl group is preferably a cyclic alkyl group having 3 to 12 carbon atoms, more preferably a cyclic alkyl group having 6 to 12 carbon atoms, a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, At least one selected from polycyclic groups such as a norbornyl group is more preferable from the viewpoint of industrial availability.
These cyclic alkyl groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

（式中、Ｒは前記と同じである。）

(In the formula, R is as defined above.)

In the polymer compound (A1), as the structural unit (a4), one type of structural unit may be used alone, or two or more types may be used in combination.
When such a structural unit (a4) is contained in the polymer compound (A1), 1 to 60 mol% of the structural unit (a4) is contained with respect to the total of all the structural units constituting the polymer compound (A1). It is preferable to contain 5 to 55 mol%, more preferably 10 to 50 mol%.

[Other structural units]
The polymer compound (A1) may have other structural units (a5) other than the structural units (a0) to (a4) as long as the effects of the present invention are not impaired.
The structural unit (a5) is not particularly limited as long as it is another structural unit not classified into the structural units (a0) to (a4) described above, and is for ArF excimer laser, for KrF excimer laser (preferably ArF excimer). A number of hitherto known materials can be used for resist resins such as lasers.
In the polymer compound (A1), as the structural unit (a5), one type of structural unit may be used alone, or two or more types may be used in combination.
When the structural unit (a5) is contained in the polymer compound (A1), 1 to 30 mol% of the structural unit (a5) is contained with respect to the total of all the structural units constituting the polymer compound (A1). It is preferable to contain 3 to 20 mol%.

In the present invention, the polymer compound (A1) is a polymer consisting only of the structural unit (a0), or at least one selected from the group consisting of the structural unit (a0) and the structural units (a1) to (a4). A copolymer with a constituent unit of a seed is preferable. The copolymer may further have a structural unit (a5).
Preferred copolymers as the polymer compound (A1) include the following copolymers (A1-1) to (A1-5).
Copolymer (A1-1): A copolymer having at least two types of structural units, including the structural units (a0) and (a1).
Copolymer (A1-2): a copolymer having at least two types of structural units, including the structural units (a0) and (a2).
Copolymer (A1-3): a copolymer having at least two types of structural units, including the structural units (a0) and (a3).
Copolymer (A1-4): A copolymer having at least two types of structural units, including the structural units (a0) and (a4).
Copolymer (A1-5): A copolymer having at least three types of structural units, including the structural units (a0), (a1), and (a2).
Copolymer (A1-6): A copolymer having at least three structural units, including the structural unit (a0) and two structural units (a3).

The copolymer (A1-1) may further have a structural unit (a5) in addition to the structural units (a0) and (a1), but is composed of the structural units (a0) and (a1). A binary copolymer is preferred.
Preferred examples of the copolymer (A1-1) include copolymers having two structural units represented by the following general formula (A1-11), and in particular, those represented by the above formula (A1-11). A copolymer composed of two kinds of structural units is preferred.

［式（Ａ１−１１）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗはそれぞれ上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｒ^３、Ｗと同じであり、Ｒ、Ｘ^１はそれぞれ上記式（ａ１−０−１）中のＲ、Ｘ^１と同じである。］

Wherein ^{(A1-11), R 1, R} 2, R 3, W are each the same as ^{R 1, R 2, R 3} , W in formula (a0-1), R, ^{X 1} is Each is the same as R and X ¹ in the above formula (a1-0-1). ]

The copolymer (A1-2) may further have a structural unit (a4) in addition to the structural units (a0) and (a2), but is composed of the structural units (a0) and (a2). A binary copolymer is preferred.
Preferred examples of the copolymer (A1-2) include a copolymer having two structural units represented by the following general formula (A1-12), and two types represented by the following general formula (A1-13). Examples thereof include a copolymer having a structural unit, and in particular, a copolymer composed of two structural units represented by the formula (A1-12), and a structural unit composed of two structural units represented by the formula (A1-13). A copolymer or the like is preferred.

［式（Ａ１−１２）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗはそれぞれ上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｒ^３、Ｗと同じであり、Ｒ、Ｒ’はそれぞれ上記式（ａ２−１）中のＲ、Ｒ’と同じである。］

Wherein ^{(A1-12), R 1, R} 2, R 3, W are each the same as ^{R 1, R 2, R 3} , W in formula (a0-1), R, R 'is Each is the same as R and R ′ in formula (a2-1). ]

［式（Ａ１−１３）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗはそれぞれ上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｒ^３、Ｗと同じであり、Ｒ、Ｒ’、Ａ”はそれぞれ上記式（ａ２−２）中のＲ、Ｒ’、Ａ”と同じである。］

Wherein ^{(A1-13), R 1, R} 2, R 3, W are each the same as ^{R 1, R 2, R 3} , W in formula (a0-1), R, R ' , A ″ is the same as R, R ′ and A ″ in the above formula (a2-2). ]

The copolymer (A1-3) may further have a structural unit (a5) in addition to the structural units (a0) and (a3), but is composed of the structural units (a0) and (a3). A binary copolymer is preferred.
Preferred examples of the copolymer (A1-3) include a copolymer having two structural units represented by the following general formula (A1-14) and two structural units represented by the following general formula (A1-15). In particular, a copolymer composed of two structural units represented by the formula (A1-14), and a copolymer composed of two structural units represented by the formula (A1-15). A coalescence or the like is preferable.

［式（Ａ１−１４）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗはそれぞれ上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｒ^３、Ｗと同じであり、Ｒ、Ｒ^４はそれぞれ上記式（ａ’３−１１）中のＲ、Ｒ^４と同じである。］

Wherein ^{(A1-14), R 1, R} 2, R 3, W are each the same as ^{R 1, R 2, R 3} , W in formula (a0-1), ^R, R ⁴ is Each is the same as R and R ⁴ in the above formula (a′3-11). ]

［式（Ａ１−１５）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗはそれぞれ上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｒ^３、Ｗと同じであり、Ｒ^５、Ｒ^６はそれぞれ上記式（ａ”３−１）中のＲ^５、Ｒ^６と同じである。］

Wherein ^(A1-15), the same as ^{R 1, R 2, R 3} , W R 1 of each of the above formulas (a0-1) in ^{the, R 2, R 3, W} , R 5, R 6 Are the same as R ⁵ and R ^{6 in the} above formula (a ″ 3-1).

The copolymer (A1-4) may further have a structural unit (a5) in addition to the structural units (a0) and (a4), but is composed of the structural units (a0) and (a4). A binary copolymer is preferred.
Preferred copolymers (A1-4) include, for example, copolymers having two structural units represented by the following general formulas (A1-16) and (A1-16 ′). A copolymer composed of two structural units shown in (A1-16) is preferred.

［式（Ａ１−１６）、（Ａ１−１６’）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗはそれぞれ上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｒ^３、Ｗと同じであり、Ｒは上記式（ａ’３−１１）中のＲと同じであり、ｎは１〜３の整数を示す。］

Expression (A1-16), (A1-16 ') ^{in, R 1, R 2, R} 3, W is the same as ^{R 1, R 2, R 3} , W of each of the above formulas (a0-1) in Yes, R is the same as R in the formula (a′3-11), and n represents an integer of 1 to 3. ]

The copolymer (A1-5) may further have a structural unit (a5) in addition to the structural units (a0), (a1), and (a2), but the structural unit (a0), ( A terpolymer comprising a1) and (a2) is preferred.
Preferred examples of the copolymer (A1-5) include a copolymer having three structural units represented by the following general formula (A1-17) and three structural units represented by the following general formula (A1-18). In particular, a copolymer consisting of three structural units represented by the formula (A1-17), and a copolymer consisting of three structural units represented by the formula (A1-18). A coalescence or the like is preferable.

［式（Ａ１−１７）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗはそれぞれ上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｒ^３、Ｗと同じであり、Ｒ、Ｘ^１はそれぞれ上記式（ａ１−０−１）中のＲ、Ｘ^１と同じであり、Ｒ、Ｒ’は上記式（ａ２−１）中のＲ、Ｒ’と同じであり、複数のＲは同じであっても異なっていてもよい。］

Wherein ^{(A1-17), R 1, R} 2, R 3, W are each the same as ^{R 1, R 2, R 3} , W in formula (a0-1), R, ^{X 1} is Each is the same as R and X ¹ in the above formula (a1-0-1), R and R ′ are the same as R and R ′ in the above formula (a2-1), and a plurality of R are the same. It may or may not be. ]

［式（Ａ１−１８）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗはそれぞれ上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｒ^３、Ｗと同じであり、Ｒ、Ｘ^１はそれぞれ上記式（ａ１−０−１）中のＲ、Ｘ^１と同じであり、Ｒ’、Ａ”はそれぞれ上記式（ａ２−２）中のＲ’、Ａ”と同じであり、複数のＲは同じであっても異なっていてもよい。］

Wherein ^{(A1-18), R 1, R} 2, R 3, W are each the same as ^{R 1, R 2, R 3} , W in formula (a0-1), R, ^{X 1} is R ′ and A ″ are the same as R and X ¹ in the above formula (a1-0-1), respectively, and R ′ and A ″ are the same as R ′ and A ″ in the above formula (a2-2), respectively. May be the same or different. ]

The copolymer (A1-6) may further have a structural unit (a5) in addition to the structural unit (a0) and the two structural units (a3). A terpolymer comprising two kinds of structural units (a3) is preferred.
Preferred examples of the copolymer (A1-6) include a copolymer having three structural units represented by the following general formula (A1-19) and three structural units represented by the following general formula (A1-20). In particular, a copolymer composed of three structural units represented by the formula (A1-19) and a copolymer composed of three structural units represented by the formula (A1-20). A coalescence or the like is preferable.

［式（Ａ１−１９）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗは上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｒ^３、Ｗと同じであり、Ｒ^５、Ｒ^６は上記式（ａ”３−１）中のＲ^５、Ｒ^６と同じであり、Ｒ、ｊは上記式（ａ’３−１）中のＲ、ｊと同じである。］

Wherein ^{(A1-19), R 1, R} 2, R 3, W is the same as ^{R 1, R 2, R 3} , W in formula ^{(a0-1), R 5, R} 6 are R ⁵ and R ⁶ in the above formula (a ″ 3-1) are the same, and R and j are the same as R and j in the above formula (a′3-1).]

［式（Ａ１−２０）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗは上記式（ａ０−１）中のＲ^１、Ｒ^２、Ｒ^３、Ｗと同じであり、Ｒ、ｊは上記式（ａ’３−１）中のＲ、ｊと同じであり、Ｒ^４１はヒドロキシアルキル基であり、複数のＲは同じであっても異なっていてもよい。］

Wherein ^{(A1-20), R 1, R} 2, R 3, W is the same as ^{R 1, R 2, R 3} , W in formula (a0-1), R, j is the formula It is the same as R and j in (a′3-1), R ⁴¹ is a hydroxyalkyl group, and a plurality of R may be the same or different. ]

In formula (A1-20), examples of the hydroxyalkyl group for R ⁴¹ include the same hydroxyalkyl groups as those described above for R ⁴ in formula (a′3-1).

When the polymer compound (A1) is used as a base material component of a negative resist composition, the polymer compound (A1) includes a polymer composed only of the structural unit (a0), a copolymer (A1-3), Copolymers (A1-4) and (A1-6) are preferred.
In this case, these polymers or copolymers preferably include, as the structural unit (a0), one in which at least one of R ² and R ³ is a hydrogen atom, and both R ² and R ³ are It is more preferable that what is a hydrogen atom is included.

When the polymer compound (A1) is used as a base component of the positive resist composition, the polymer compound (A1) includes a polymer composed only of the structural unit (a0), a copolymer (A1-1), A copolymer (A1-2), a copolymer (A1-5), etc. are preferable.
However, in the case where the polymer compound (A1) does not contain the structural unit (a1) like a polymer composed only of the structural unit (a0), at least one of R ² and R ³ is It must be an acid dissociable, dissolution inhibiting group.

The mass average molecular weight (Mw) of the polymer compound (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but when used as a base component of a negative resist composition, 1000-8000 are preferable, 2000-7000 are more preferable, and 2500-6500 are the most preferable. Moreover, when using as a base-material component of a positive resist composition, 3000-50000 are preferable, 4000-30000 are more preferable, 4000-20000 are the most preferable. When Mw is smaller than the upper limit of these ranges, there is sufficient solubility in a resist solvent to be used as a resist. When Mw is larger than the lower limit of these ranges, dry etching resistance and resist pattern cross-sectional shape are good. is there.
The dispersity (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 4.0, and most preferably 1.2 to 3.8. In addition, Mn shows a number average molecular weight.

The polymer compound (A1) has a property that the solubility in an alkali developer is changed by the action of an acid generated from an acid generator component upon exposure. For example, when used as a base component of a negative resist composition, a polymer compound (A1) that is soluble in an alkaline developer before exposure is used. In the polymer compound (A1), when an acid is generated from the acid generator component by exposure, a crosslinking reaction occurs between the polymer compound (A1) and the crosslinking agent component blended with the polymer compound (A1) by the action of the acid. The polymer compound (A1) changes to hardly soluble in the alkali developer.
In addition, when used as a base component of a positive resist composition, the polymer compound (A1) has an acid dissociable, dissolution inhibiting group, and has increased solubility in an alkali developer due to the action of an acid. Used. Such a polymer compound (A1) is hardly soluble in an alkali developer before exposure, and when acid is generated from the acid generator component by exposure, the acid dissociable dissolution inhibiting group is dissociated by the action of the acid. , The solubility in an alkali developer increases.

[Production of polymer compound (A1)]
In the polymer compound (A1), a monomer for deriving each structural unit was used, for example, a radical polymerization initiator such as dimethyl-2,2-azobis (2-methylpropionate) or azobisisobutyronitrile. It can be obtained by polymerization by known radical polymerization or the like.
Further, in the polymer compound (A1), a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination in the above polymerization. it may be introduced -C _{(CF 3)} 2 -OH group at the terminal. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing

The polymer compound (A1) is a novel compound.
The monomer for deriving the structural unit (a0) is a compound represented by the following general formula (I) (hereinafter referred to as compound (I)).

［式（Ｉ）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｗはそれぞれ前記と同じである。］

[In the formula (I), R ¹ , R ² , R ³ and W are the same as defined above. ]

^R 1 in formula ^{(I), R 2, R} 3, W is the same as ^{R 1, R 2, R 3} , W of respective general formula (a0-1).
Although a process for the preparation of compounds (I) is not particularly limited, a preferred method, for example, the general formula _{^{XSO 2 NR 2 R 3 ... (}} II)
[In Formula (II), X represents a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and R ² and R ³ are the same as defined above. ]
The method of obtaining the compound (I) by adding the alcohol derivative represented with the following general formula (III) to the reaction system containing the compound represented by these is mentioned.

［式（ＩＩＩ）中、Ｒ^１は前記と同じである。］

[In formula (III), R ¹ is as defined above. ]

^R 2, ^{R 3} in formula (II) is the same as ^R 2, ^{R 3} of each of the formulas (a0-1).
^R 1, W in formula (III) is the same as ^R 1, W in general formula (a0-1).
Specific examples of the method for producing compound (I) include, for example, producing 3-sulfamoyloxyadamantan-1-yl acrylate by reacting 3-hydroxyadamantan-1-yl acrylate with ClSO ₂ NH _2. can do.
The structure of the compound obtained as described above includes ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method, mass spectrometry (MS ) Method, elemental analysis method, X-ray crystal diffraction method, etc.

The polymer compound (A1) of the present invention is a novel compound not conventionally known.
The polymer compound (A1) of the present invention is a so-called chemical amplification type containing a base material component whose solubility in an alkaline developer is changed by the action of an acid and an acid generator component that generates an acid upon exposure. The resist composition is useful as a base component of the resist composition. For example, according to a resist composition containing the polymer compound (A1) as a base component, a resist pattern with excellent resolution can be formed.
The reason why the above effect is obtained is not clear, but the structural unit (a0) of the polymer compound (A1) includes a structure represented by OSO ₂ N (R ² ) R ³ at the side chain end, The polymer compound (A1) has appropriate alkali solubility required for a positive resist composition or a negative resist composition, and W (cyclic alkylene group) of the structural unit (a0) and Since all of the sulfamoyloxy groups (OSO ₂ N groups) are relatively excellent in transparency, the polymer compound (A1) is highly transparent, particularly highly transparent to light having a wavelength of around 193 nm. It is estimated that

The polymer compound (A1) of the present invention is particularly useful when the resist composition is a negative type and a crosslinking agent component is blended.
Conventionally, a polymer compound having a fluorinated hydroxyalkyl group has been used as a base component of a negative resist composition. The polymer compound having a fluorinated hydroxyalkyl group is said to be excellent in that it has moderate alkali solubility. However, the hydroxyl group of the fluorinated hydroxyalkyl group does not contribute to the crosslinking reaction due to the influence of steric hindrance caused by the fluorinated alkyl group, and this hinders improvement in the crosslinking density.
On the other hand, the polymer compound (A1) of the present invention has the structural unit (a0), so that it has excellent transparency near the wavelength of 193 nm and has moderate alkali solubility, as described above. The side chain terminal part (SO ₂ NH group, SO ₂ NH ₂ group, etc.) of the unit (a0) has reactivity with the crosslinking agent component (crosslinking reactivity), and is generated from the acid generator component by exposure. It can react with the crosslinker component by the action of an acid to form a crosslink. Therefore, when forming a negative resist pattern, the crosslink density of the exposed portion can be easily improved, and the alkali insolubility of the resist composition in the exposed portion is improved, so that the alkali between the exposed portion and the unexposed portion is improved. It is presumed that a difference in solubility (dissolution contrast) in the developer is improved, and a negative resist pattern having excellent resolution can be formed.

Below, one Embodiment of the resist composition in which the high molecular compound (A1) of this invention is used is shown.
≪Resist composition≫
The resist composition of this embodiment includes a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid (hereinafter referred to as (A) component), and an acid generator component that generates an acid upon exposure. (B) (hereinafter referred to as component (B)).
When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the component (B), and the acid has a solubility in the alkaline developer of the component (A). Change. As a result, while the solubility of the exposed portion of the resist film in the alkaline developer changes, the unexposed portion does not change the solubility in the alkaline developer. In the case of the negative type, the unexposed part is dissolved and removed, and a resist pattern is formed.
At this time, the case of changing from poorly soluble to soluble in an alkali developer is positive, and the case of changing from soluble to hardly soluble in an alkaline developer is negative.
The resist composition of the present embodiment may be a negative resist composition or a positive resist composition. A negative resist composition is preferred, and in this case, a crosslinking agent component (C) (hereinafter referred to as (C) component) is further blended.

<(A) component>
The resist composition of this embodiment contains the polymer compound (A1) of the present invention as the component (A).
In the component (A), the polymer compound (A1) may be used alone or in combination of two or more.
The resist composition of this embodiment may contain only the polymer compound (A1) as the component (A), and in addition to the polymer compound (A1), groups other than the polymer compound (A1) You may contain a material component (henceforth (A2) component).
In the component (A), the proportion of the polymer compound (A1) is preferably 50% by mass or more, more preferably 80 to 100% by mass, and most preferably 100% by mass.
The component (A2) is not particularly limited, and any component that has been proposed as a base component for a chemically amplified resist can be appropriately selected and used.
The content of the component (A) in the resist composition is not particularly limited, and may be adjusted according to the resist film thickness to be formed. Usually, the higher the concentration of the component (A) in the organic solvent solution of the resist composition, the thicker the resist film is formed.

<(B) component>
(B) It does not specifically limit as a component, What has been proposed as an acid generator for chemical amplification type resists until now can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like. Among these, an onium salt acid generator is preferable, and an onium salt having a fluorinated alkyl sulfonate ion as an anion is particularly preferable.
(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
The content of the component (B) in the resist composition is preferably 0.5 to 30 parts by mass, more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the component (A).

<(C) component>
When the resist composition of the present invention is a negative resist composition, the resist composition preferably further contains a component (C).
The component (C) is not particularly limited and can be arbitrarily selected from those previously proposed as crosslinking agents for chemically amplified negative resists.
Specifically, for example, 2,3-dihydroxy-5-hydroxymethylnorbornane, 2-hydroxy-5,6-bis (hydroxymethyl) norbornane, cyclohexanedimethanol, 3,4,8 (or 9) -trihydroxytri Aliphatic cyclic carbonization having a hydroxyl group or a hydroxyalkyl group or both such as cyclodecane, 2-methyl-2-adamantanol, 1,4-dioxane-2,3-diol, 1,3,5-trihydroxycyclohexane Examples thereof include hydrogen and oxygen-containing derivatives thereof.
In addition, amino group-containing compounds such as melamine, acetoguanamine, benzoguanamine, urea, ethylene urea, propylene urea, glycoluril are reacted with formaldehyde or formaldehyde and a lower alcohol, and the hydrogen atom of the amino group is converted into a hydroxymethyl group or a lower alkoxymethyl. And a compound substituted with a group and a compound having an epoxy group.
Of these, those using melamine are melamine crosslinking agents, those using urea are urea crosslinking agents, those using alkylene ureas such as ethylene urea and propylene urea are alkylene urea crosslinking agents, and glycoluril is used. What was used was a glycoluril-based crosslinking agent, and what used an epoxy group-containing compound was called an epoxy-based crosslinking agent.
Component (C) is preferably at least one selected from the group consisting of melamine-based crosslinking agents, urea-based crosslinking agents, alkylene urea-based crosslinking agents, glycoluril-based crosslinking agents, and epoxy-based crosslinking agents, and particularly glycol. Uril-based crosslinking agents are preferred.

(C) A component may be used individually by 1 type and may be used in combination of 2 or more type.
As the component (C), it is usually preferable to use an amino cross-linking agent such as glycoluril having a methylol group or an alkoxymethyl group because a good resist pattern with less swelling can be formed.
The content of the component (C) in the resist composition is preferably 1 to 50 parts by weight, more preferably 3 to 30 parts by weight, and 3 to 15 parts by weight with respect to 100 parts by weight of the component (A). More preferred is 5 to 10 parts by mass. When the content of the component (C) is at least the lower limit value, crosslinking formation proceeds sufficiently and a good resist pattern with little swelling is obtained. Moreover, when it is less than or equal to this upper limit value, the storage stability of the resist coating solution is good, and the deterioration of sensitivity over time is suppressed.

<Optional component>
The resist composition of the present invention includes, as an optional component (hereinafter referred to as “component (D)”), a nitrogen-containing organic compound for improving the resist pattern shape, stability over time, etc .; prevention of sensitivity deterioration, resist pattern shape Organic carboxylic acids, organic carboxylic acid derivatives, phosphorus oxoacids, phosphorus oxoacid derivatives; additional resins to improve resist film performance; improved coatability A surfactant, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained.

<Organic solvent>
The resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution, and any one of conventionally known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
The amount of the component (S) used is not particularly limited, but is a concentration that can be applied to the support and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 2 -20% by mass, preferably 3-15% by mass.

As a resist pattern forming method using the resist composition, a step of forming a resist film on the support using the resist composition, a step of exposing the resist film, and an alkali development of the resist film are performed. Examples thereof include a method including a step of forming a resist pattern.
The resist pattern forming method can be performed, for example, as follows.
That is, first, the resist composition is coated on a support with a spinner or the like, and optionally pre-baked (post-apply bake (PAB) for 40 to 120 seconds, preferably 60 to 90 seconds at a temperature of about 80 to 150 ° C. )) To form a resist film. The formed resist film is exposed by exposure through a mask pattern using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus, or by drawing by direct irradiation of an electron beam without using a mask pattern. After the selective exposure, PEB (post-exposure heating) is performed at a temperature of about 80 to 150 ° C. for 40 to 120 seconds, preferably 60 to 90 seconds. Subsequently, after alkali development using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH), a water rinse treatment is preferably performed using pure water, followed by drying. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist pattern faithful to the mask pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC).
The wavelength used for the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The resist composition is particularly effective for ArF excimer laser.
The exposure of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
[Synthesis Example 1: Synthesis of 3-sulfamoyloxyadamantyl acrylate]
A 5 L four-necked flask equipped with a thermometer, a dropping funnel and a stirrer was charged with nitrogen, and 980 g of heptane and 334 g (2.4 mol) of chlorosulfonyl isocyanate were charged from the dropping funnel. After cooling internal temperature to 5 degreeC, 110 g (2.4 mol) of formic acid was dripped from the dropping funnel at the speed | rate which can maintain internal temperature 5-8 degreeC. After completion of dropping, the internal temperature was raised to 20 ° C. and stirred for 10 hours. A solution of 175 g (0.79 mol) of 3-hydroxyadamantyl acrylate, 525 g of N-methylpyrrolidone, 2.1 g of 4-methoxyphenol and 2.1 g of phenothiazine is added to the reaction mixture from an addition funnel at an internal temperature of 20 ° C. or lower. It was dripped at a speed that can be maintained. After stirring at an internal temperature of 20 to 25 ° C. for 3 hours, the reaction mixture was transferred to a separatory funnel and the upper layer was discarded. To the resulting lower layer, 890 g of ethyl acetate and 700 g of water were added, stirred, allowed to stand, and then separated. 890 g of ethyl acetate was added to the aqueous layer and re-extracted. Two ethyl acetate layers were mixed and then washed five times with 900 g of water. Subsequently, it was washed with 400 g of a 7% by mass-aqueous sodium hydrogen carbonate solution and 400 g of water. After the washing, the organic layer was concentrated under reduced pressure to 500 g, and then 630 g of toluene was added. After heating to an internal temperature of 55 ° C., the mixture was cooled to 3 ° C. and recrystallized. By filtering the resulting suspension, 145 g (0.48 mol) of 3-sulfamoyloxyadamantyl acrylate represented by the following chemical formula was obtained as crystals (yield = 61%).

The ¹ H-NMR analysis result of the obtained 3-sulfamoyloxyadamantyl acrylate is shown below.
¹ H-NMR (300 MHz, DMSO-d ₆ , TMS, ppm) δ: 7.44 (2H, s), 6.26 (1H, m), 6.07 (1H, m,), 3.34 ( 1H, s), 2.48 (3H, s), 2.34 (2H, s), 2.04 (6H, m), 1.52 (2H, s).

[Synthesis Example 2: Synthesis of 3-sulfamoyloxyadamantyl methacrylate]
The same operation as in Synthesis Example 1 was carried out except that 186.7 g (0.79 mol) of 3-hydroxyadamantyl methacrylate was used instead of 175 g (0.79 mol) of 3-hydroxyadamantyl acrylate. -159.5 g (0.51 mol) of sulfamoyloxyadamantyl methacrylate was obtained (yield = 64%).

The ¹ H-NMR analysis result of the obtained 3-sulfamoyloxyadamantyl methacrylate is shown below.
¹ H-NMR (300 MHz, DMSO-d ₆ , TMS, ppm) δ: 7.43 (2H, s), 5.96 (1H, s), 5.62 (1H, s), 2.48 (2H , S), 2.35 (3H, br), 2.23 (1H, s), 2.04 (6H, m), 1.84 (3H, s) 1.52 (2H, s).

[Example 1]
After charging 13.0 g of propylene glycol monomethyl ether into a 100 ml four-necked flask equipped with a thermometer, a nitrogen introducing tube, a dropping funnel, and a stirring device, nitrogen was bubbled through the nitrogen introducing tube for 15 minutes. Next, after raising the internal temperature to 80 ° C., 7.0 g (mmol) of 3-sulfamoyloxyadamantyl acrylate, 0.05 g (0.3 mmol) of azobisisobutyronitrile and propylene glycol monomethyl ether 22 were added from the dropping funnel. .6 g of solution was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was stirred at 80 to 83 ° C. for 3 hours, cooled to 25 ° C., and the reaction solution was dropped into 309 g of diisopropyl ether. The resulting precipitate was filtered using a glass filter, and the obtained powder was dissolved in 28 g of propylene glycol monomethyl ether and added dropwise to a mixed solvent of 136 g of diisopropyl ether and 15 g of ethyl acetate. The resulting precipitate was filtered using a glass filter, and the obtained powder was dried at 40 ° C. under reduced pressure for 8 hours. 5.6 g of a polymer (polymer compound (1)) represented by the following formula (1) having a weight average molecular weight = 6100 and a molecular weight dispersity = 1.35 was obtained (yield = 80%). In the formula, the numerical value on the lower right of () indicates the proportion (mol%) of the structural unit to which the numerical value is attached.

[Example 2]
14.8 g of propylene glycol monomethyl ether was charged into a 100 ml four-necked flask equipped with a thermometer, a nitrogen introducing tube, a dropping funnel, and a stirring device, and then nitrogen was bubbled through the nitrogen introducing tube for 15 minutes. Next, after the internal temperature was raised to 80 ° C., 4.0 g (13.3 mmol) of 3-sulfamoyloxyadamantyl acrylate and 2.9 g (13.1 mmol) of 3-hydroxyadamantyl acrylate were added from the dropping funnel. A solution of 0.06 g (0.3 mmol) of nitrile and 26.6 g of propylene glycol monomethyl ether was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was stirred at 80 to 83 ° C. for 3 hours, and then the reaction solution was dropped into 204 g of diisopropyl ether. The resulting precipitate was filtered using a glass filter, and the obtained powder was redissolved in 20 g of propylene glycol monomethyl ether. The solution was dropped into a mixed solvent of 117 g of diisopropyl ether and 13 g of ethyl acetate, the resulting precipitate was filtered using a glass filter, and the obtained solid was dried under reduced pressure to obtain a mass average molecular weight of 5600 and a dispersity. The copolymer (polymer compound (2)) 5.0g represented by following formula (2) of 1.40 was obtained (yield 72%). In the formula, the numerical value on the lower right of () indicates the proportion (mol%) of the structural unit to which the numerical value is attached.

[Example 3]
After charging 14.0 g of propylene glycol monomethyl ether into a 100 ml four-necked flask equipped with a thermometer, a nitrogen introduction tube, a dropping funnel, and a stirrer, nitrogen was bubbled through the nitrogen introduction tube for 15 minutes. Next, after raising the internal temperature to 80 ° C., 6.1 g (20.1 mmol) of 3-sulfamoyloxyadamantyl acrylate and 2.4 g (20.4 mmol) of 2-hydroxyethyl acrylate are added from the dropping funnel. A solution of 0.08 g (0.5 mmol) of nitrile and 22.0 g of propylene glycol monomethyl ether was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was stirred at 80 to 83 ° C. for 3 hours, and then the reaction solution was dropped into 204 g of diisopropyl ether. The resulting precipitate was filtered using a glass filter, and the obtained powder was redissolved in 20 g of propylene glycol monomethyl ether. The solution was dropped into a mixed solvent of 117 g of diisopropyl ether and 13 g of ethyl acetate, and the resulting precipitate was filtered using a glass filter, and then the obtained solid was dried under reduced pressure, whereby a weight average molecular weight of 7000 and a molecular weight dispersion were obtained. 5.9 g of a copolymer (polymer compound (3)) represented by the following formula (3) having a degree of 1.50 was obtained (yield = 70%). In the formula, the numerical value on the lower right of () indicates the proportion (mol%) of the structural unit to which the numerical value is attached.

<Example 4>
After charging 33.2 g of propylene glycol monomethyl ether into a 200 ml four-necked flask equipped with a thermometer, a nitrogen introducing tube, a dropping funnel, and a stirring device, nitrogen was bubbled through the nitrogen introducing tube for 15 minutes. Subsequently, after raising the internal temperature to 78 ° C., 6.10 g (20.2 mmol) of 3-sulfamoyloxyadamantyl acrylate and 2.79 g (13.5 mmol) of adamantyl acrylate were added from the dropping funnel to a solution of 0.8% of azobisisobutyronitrile. A solution of 22 g (1.35 mmol) and 33.2 g of propylene glycol monomethyl ether was added dropwise over 3 hours. After the completion of dropping, the mixture was stirred at 78 to 80 ° C. for 2 hours, and then the reaction solution was dropped into 300 g of n-hexane. The filtrate was removed by decantation, and the resulting precipitate was redissolved in 27.6 g of propylene glycol monomethyl ether. The solution was dropped into a mixed solvent of 360 g of n-hexane and 40 g of isopropyl alcohol, the filtrate was removed by decantation, and the obtained solid was dried under reduced pressure to obtain a mass average molecular weight of 3800 and a dispersity of 1.48 shown below. 6.2 g of a copolymer (polymer compound (4)) represented by the formula (4) was obtained (yield 70%). In the formula, the numerical value on the lower right of () indicates the proportion (mol%) of the structural unit to which the numerical value is attached.

<Example 5>
After charging 23.3 g of propylene glycol monomethyl ether into a 200 ml four-necked flask equipped with a thermometer, a nitrogen inlet tube, a dropping funnel, and a stirrer, nitrogen was bubbled through the nitrogen inlet tube for 15 minutes. Subsequently, after raising the internal temperature to 78 ° C., 6.10 g (20.2 mmol) of 3-sulfamoyloxyadamantyl acrylate and 2.79 g (13.5 mmol) of adamantyl acrylate were added from the dropping funnel to a solution of 0.8% of azobisisobutyronitrile. A solution of 14 g (0.85 mmol) and 42.0 g of propylene glycol monomethyl ether was added dropwise over 3 hours. After the completion of dropping, the mixture was stirred at 78 to 80 ° C. for 2 hours, and then the reaction solution was dropped into 300 g of n-hexane. The filtrate was removed by decantation, and the resulting precipitate was redissolved in 23.4 g of propylene glycol monomethyl ether. The solution was dropped into a mixed solvent of 270 g of n-hexane and 30 g of isopropyl alcohol, the filtrate was removed by decantation, and the obtained solid was dried under reduced pressure to obtain a mass average molecular weight of 6040 and a dispersity of 1.37 shown below. 3.7 g of a copolymer (polymer compound (5)) represented by the formula (5) was obtained (42% yield). In the formula, the numerical value on the lower right of () indicates the proportion (mol%) of the structural unit to which the numerical value is attached.

<Example 6>
After charging 37.0 g of propylene glycol monomethyl ether into a 200 ml four-necked flask equipped with a thermometer, a nitrogen introduction tube, a dropping funnel, and a stirrer, nitrogen was bubbled through the nitrogen introduction tube for 15 minutes. Next, after raising the internal temperature to 80 ° C., 9.0 g (29.9 mmol) of 3-sulfamoyloxyadamantyl acrylate, 1.54 g (7.5 mmol) of adamantyl acrylate, azobisisobutyronitrile 0 from the dropping funnel A solution of .17 g (1.9 mmol) and 69.6 g of propylene glycol monomethyl ether was added dropwise over 3 hours. After completion of dropping, the mixture was stirred at 80 ° C. for 2 hours, and then the reaction solution was dropped into 2200 g of diisopropyl ether. The resulting precipitate was filtered using a glass filter, and the obtained solid was dried under reduced pressure to obtain a copolymer (polymer) represented by the following formula (6) having a mass average molecular weight of 4300 and a dispersity of 1.31. Compound (6)) 7.7g was obtained (yield 73%). In the formula, the numerical value on the lower right of () indicates the proportion (mol%) of the structural unit to which the numerical value is attached.

[Reference Examples 1 to 6]
Each component shown in Table 1 was mixed and dissolved to prepare a negative resist composition.

Each abbreviation in Table 1 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1: the polymer compound (1).
(A) -2: the polymer compound (2).
(A) -4: The polymer compound (4).
(A) -5: The polymer compound (5).
(A) -6: the polymer compound (6).
(A) -1 ′: a polymer having a mass average molecular weight of 5000 represented by the above formula (1).
(B) -2: Triphenylsulfonium trifluoromethanesulfonate.
(C) -1: A compound represented by the following chemical formula (C) -1 (tetramethoxymethylated glycoluril, product name: Nicalac MX-270, manufactured by Sanwa Chemical Co., Ltd.).
(D) -1: Triisopropanolamine.
(S) -1: Propylene glycol monomethyl ether (PGME).

The following evaluation was performed using the obtained resist composition.
[Evaluation of residual film properties]
An organic antireflective coating composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is uniformly applied on an 8-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a thickness of 77 nm was formed.
The resist composition is applied onto the organic antireflection film using a spinner, pre-baked (PAB) at 90 ° C. for 60 seconds on a hot plate, and dried to obtain a film thickness. A 160 nm resist film was formed.
An ArF excimer laser (193 nm) was applied to the resist film with an ArF exposure apparatus NSR-S302 (product name, manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination). It exposed with the exposure amount of 30 mJ / cm < ² >. Thereafter, a post-exposure heating (PEB) treatment was performed at 110 ° C. for 60 seconds, followed by development with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution at 23 ° C. for 60 seconds, followed by washing with water for 30 seconds and drying. did.
At this time, a residual film curve was obtained from the change in the residual film ratio (unit:%, resist film thickness after development / resist film thickness during film formation (before exposure) × 100) due to the change in exposure amount. As a result, all the resist compositions of Reference Examples 1 to 6 showed good contrast. Moreover, the maximum remaining film rate (convergence value of the remaining film rate) is respectively Reference Example 1 (73%), Reference Example 2 (96%), Reference Example 3 (99.6%), and Reference Example 4 (60%). ), Reference Example 5 (100%), and Reference Example 6 (70%).
From the above results, it was confirmed that the resist compositions of Reference Examples 1 to 6 were excellent in residual film characteristics and functioned as negative resist compositions.

[Evaluation of lithography properties]
An organic antireflective coating composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is uniformly applied on an 8-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a thickness of 77 nm was formed.
On the organic antireflection film, the resist composition of Reference Example 2 was applied using a spinner, prebaked (PAB) at 90 ° C. for 60 seconds on a hot plate, and dried to form a film. A resist film having a thickness of 160 nm was formed.
An ArF excimer laser (193 nm) is applied to the resist film by using an ArF exposure apparatus NSR-S302 (product name, manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination) as a mask pattern. Selectively irradiated. Thereafter, PEB treatment was carried out at 110 ° C. for 60 seconds, followed by development with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution at 23 ° C. for 60 seconds, followed by washing with water for 30 seconds and drying.
As a result, the resolution of a line-and-space resist pattern (LS pattern) having a line width of 250 nm and a pitch of 500 nm was confirmed.
At this time, the optimum exposure dose Eop (mJ / cm ² ) at which an LS pattern having a line width of 250 nm and a pitch of 500 nm was formed was determined as “sensitivity”. As a result, the Eop of Reference Example 2 was 35 mJ / cm ² .
In addition, as “resolution”, the limit resolution (nm) in the Eop was determined using a length measurement SEM (scanning electron microscope) S-9220 (manufactured by Hitachi). As a result, the limit resolution of Reference Example 2 was 150 nm.

  From the above results, it was confirmed that the polymer compound of the present invention was useful as a base component of the resist composition.

Claims (5)

The high molecular compound which has a structural unit (a0) represented by the following general formula (a0-1).

[In Formula (a0-1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and R ² and R ³ are each independently a hydrogen atom. Or, it represents an alkyl group which may contain an oxygen atom at any position, or they are bonded to each other to represent an alkylene group, and W represents a cyclic alkylene group which may contain an oxygen atom at any position. . ] The polymer compound according to claim 1, wherein R ² in the general formula (a0-1) is a hydrogen atom. The polymer compound according to claim 1, wherein R ² and R ³ in the general formula (a0-1) are hydrogen atoms.   Furthermore, the high molecular compound as described in any one of Claims 1-3 which has a structural unit induced | guided | derived from the acrylate ester containing a hydroxyl group.   Furthermore, the high molecular compound in any one of Claims 1-4 which has the structural unit induced | guided | derived from the non-acid dissociable acrylic acid cyclic alkylester.