WO2016098809A1 - Pattern formation method, composition for protective film formation, and method for producing electronic device - Google Patents

Abstract

A pattern formation method including: (a) a step for applying a coating of an actinic ray-sensitive or a radiation-sensitive resin composition onto a substrate, and forming an actinic ray-sensitive or a radiation-sensitive film; (b) a step for applying a coating of a composition for protective film formation onto the actinic ray-sensitive or radiation-sensitive film, and forming a protective film; (c) a step for causing the actinic ray-sensitive or radiation-sensitive film coated with the protective film to be exposed to light; and (d) a step for developing the exposed actinic ray-sensitive or radiation-sensitive film with a developer containing an organic solvent. The protective film contains a resin (X) having a proton acceptor functional group.

Description

Pattern forming method, protective film forming composition and electronic device manufacturing method

INDUSTRIAL APPLICABILITY The present invention is suitably used in a pattern forming method used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal and a thermal head, and other photofabrication lithography processes. The present invention relates to a protective film-forming composition and an electronic device manufacturing method. The present invention relates to a pattern forming method suitable for exposure with an immersion projection exposure apparatus, a protective film forming composition used in the pattern forming method, and an electronic device manufacturing method.

Since the resist for KrF excimer laser (248 nm), an image forming method called chemical amplification has been used as an image forming method for a resist in order to compensate for sensitivity reduction due to light absorption. An example of a positive-type chemical amplification image forming method is as follows. When exposed, the acid generator in the exposed area decomposes to generate an acid, and the exposed acid is used as a reaction catalyst in a post-exposure bake (Post Exposure Bake: PEB). Is used to change an alkali-insoluble group to an alkali-soluble group, and an exposed portion is removed by alkali development.
On the other hand, in addition to the positive type, in recent years, a negative type image forming method (hereinafter referred to as “NTI process” (negative tone imaging) using a developer containing an organic solvent (hereinafter also referred to as “organic solvent developer”). NTI)) is also being developed (see, for example, Patent Documents 1 and 2). For example, in Patent Document 2, in pattern formation by alkali development using a conventional negative resist composition, swelling during development is presumed to be the main factor. Line Width Roughness (LWR), focus margin In view of the need for further improvements in depth of focus (DOF) and other performances, in a negative pattern forming method using a developer containing an organic solvent, at least one of fluorine atoms and silicon atoms A chemically amplified resist composition to which a specific compound containing is added is used.
Also, for the miniaturization of semiconductor elements, the wavelength of the exposure light source has been shortened and the numerical aperture (high NA) of the projection lens has been advanced. Currently, an exposure machine using an ArF excimer laser having a 193 nm wavelength as a light source has been developed. Yes. Further, as a technique for further increasing the resolving power, a so-called immersion method in which a high refractive index liquid (hereinafter also referred to as “immersion liquid”) is filled between the projection lens and the sample has been proposed.
It is pointed out that when chemically amplified resist is applied to immersion exposure, the resist layer comes into contact with the immersion liquid at the time of exposure, so that the resist layer is altered and components that adversely affect the immersion liquid are leached from the resist layer. Has been. Patent Document 3 describes an example in which resist performance is changed by immersing a resist for ArF exposure in water before and after exposure, and points out a problem in immersion exposure.
As a solution to avoid such a problem, a method is known in which a protective film (hereinafter also referred to as “top coat”) is provided between the resist and the lens so that the resist and water do not come into direct contact with each other. (For example, see Patent Documents 4 to 6).
If an acid is excessively generated on the resist surface due to decomposition of the acid generator by exposure, an excessive deprotection reaction of the acid-decomposable group is caused on the surface layer, and in the NTI process in which the exposed portion is left as a pattern after development, the pattern is T-top. Easy to shape. When the pattern has a T-top shape, for example, performance such as focus margin (DOF) and exposure latitude (EL) is deteriorated. For this reason, for example, Patent Documents 7 and 8 disclose a technique of adding a low molecular basic quencher to the topcoat layer covering the resist film for the purpose of neutralizing excess acid generated on the resist surface. Yes.

JP 2008-292975 A JP 2011-141494 A International Publication No. 04-068242 International Publication No. 04-074937 International Publication No. 05-019937 JP-A-2005-109146 JP 2013-61647 A JP 2013-61648 A

As a result of intensive studies by the present inventors, when a basic quencher is added to the topcoat layer, the excessively generated acid moves from the resist surface layer to the topcoat layer, while the low molecular base from the topcoat layer to the resist layer. Sex quencher moves. For this reason, it was found that the film thickness of the pattern was reduced and the line edge roughness (LER) was deteriorated. This is a serious problem in the NTI process that leaves the exposed area as a pattern after development.
The present invention is excellent in focus margin (DOF) and exposure margin (EL) in an NTI process, that is, a negative type image forming process using an organic solvent developer, and suppresses line width variation (LER). It is an object of the present invention to provide a pattern forming method capable of forming a different pattern, and a protective film forming composition suitably used in the pattern forming method. Another object of the present invention is to provide an electronic device manufacturing method including the pattern forming method.

In one aspect, the present invention is as follows.
[1]
(a) applying an actinic ray-sensitive or radiation-sensitive resin composition on a substrate to form an actinic ray-sensitive or radiation-sensitive film;
(b) applying a protective film-forming composition on the actinic ray-sensitive or radiation-sensitive film to form a protective film;
(c) a step of exposing the actinic ray-sensitive or radiation-sensitive film coated with the protective film; and (d) a developer containing the exposed actinic ray-sensitive or radiation-sensitive film with an organic solvent. A pattern forming method including a step of developing with
The pattern formation method in which the said protective film contains resin (X) which has a proton acceptor functional group.
[2]
The pattern forming method according to [1], wherein the proton acceptor functional group is a functional group containing a nitrogen atom constituting an aliphatic amine, an aromatic amine or a heterocyclic amine.
[3]
The pattern forming method according to [1], wherein the proton acceptor functional group is an ether bond, a thioether bond, a carbonyl bond, or a thiocarbonyl bond.
[4]
Resin (X) includes a repeating unit having the proton acceptor functional group, and the content of this repeating unit is 0.1 to 10 mol% with respect to all the repeating units in the resin (X). The pattern forming method according to any one of [1] to [3].
[5]
The pattern forming method according to any one of [1] to [4], wherein the resin (X) is a resin that substantially does not contain a fluorine atom.
[6]
After the step (b) for forming the protective film and before the step (c) for exposing, a step of heating the substrate coated with the actinic ray-sensitive or radiation-sensitive film and the protective film at 100 ° C. or higher The pattern forming method according to any one of [1] to [5], further comprising:
[7]
A composition for forming a protective film used for forming a protective film covering an actinic ray-sensitive or radiation-sensitive film, comprising a resin (X) having a proton-accepting functional group, and the proton-accepting property The composition for protective film formation whose functional group is a functional group containing the nitrogen atom which comprises an aliphatic amine, an aromatic amine, or a heterocyclic amine.
[8]
A composition for forming a protective film used for forming a protective film covering an actinic ray-sensitive or radiation-sensitive film, comprising a resin (X) having a proton-accepting functional group, and the proton-accepting property A composition for forming a protective film, wherein the functional group is an ether bond, a thioether bond, a carbonyl bond or a thiocarbonyl bond.
[9]
[1] A method for manufacturing an electronic device comprising the pattern forming method according to any one of [6].
[10]
The electronic device manufactured by the manufacturing method of the electronic device as described in [9].

According to the present invention, a pattern forming method capable of forming a pattern having excellent focus margin (DOF) and exposure margin (EL) and suppressing line width variation (LWR), and this pattern forming method It has become possible to provide a composition for forming a protective film that can be suitably used in the present invention. In addition, according to the present invention, it is possible to provide an electronic device manufacturing method including this pattern forming method.

Hereinafter, embodiments of the present invention will be described in detail.
In the notation of groups (atomic groups) in this specification, the notation that does not indicate substitution and non-substitution includes not only those having no substituent but also those having a substituent. For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

In the present specification, “active light” or “radiation” means, for example, an emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer laser, extreme ultraviolet rays (EUV light), X-rays, electron beams (EB) and the like. . In the present invention, light means actinic rays or radiation.

In addition, the term “exposure” in this specification means not only exposure with far ultraviolet rays, extreme ultraviolet rays, X-rays, EUV light, etc. represented by mercury lamps and excimer lasers, but also electron beams, ion beams, etc. Drawing with particle beams is also included in the exposure.

Hereinafter, the pattern forming method of the present invention, the protective film forming composition suitably used in the pattern forming method, and the actinic ray-sensitive or radiation-sensitive resin composition will be described in detail.

<Composition for protective film formation>
The pattern forming method of the present invention includes a protective film forming step of forming a protective film so as to cover an actinic ray-sensitive or radiation-sensitive film in an NTI process for forming a negative image using an organic solvent developer. . The composition for forming a protective film used for forming the protective film contains a resin (X) described below. The protective film-forming composition preferably contains a solvent in order to uniformly form a film on the actinic ray-sensitive or radiation-sensitive film. In addition, the protective film-forming composition may further contain a surfactant.

[Resin (X)]
Resin (X) contains a proton acceptor functional group. As described in detail below, the proton acceptor functional group is a group capable of electrostatically interacting with a proton or a functional group having a lone pair of electrons.

As described above, the acid generated excessively on the resist surface layer by exposure is neutralized with a low-molecular basic quencher added to the topcoat layer, thereby suppressing the pattern shape from becoming T-top. Techniques for suppressing degradation of EL performance are known (see Patent Documents 7 and 8).

However, as a result of intensive studies by the present inventors, the low molecular basic quencher quenches and neutralizes the acid transferred from the resist surface layer to the top coat layer, while the low molecular base from the top coat layer to the resist layer. As a result of the movement of the sex quencher and also quenching and neutralizing the acid in the resist exposure area, a problem has been found that the film loss of the pattern is caused and the LER is deteriorated.

As a result of further intensive studies by the present inventors, the resin in the protective film-forming composition carries a proton acceptor functional group instead of adding a low molecular basic quencher to the protective film-forming composition. As a result, it has been found that a pattern can be formed with a reduced LER by suppressing film loss while suppressing the pattern shape from becoming a T-top shape and improving DOF and EL performance.

The reason why the LER is reduced by suppressing the occurrence of film reduction while improving the DOF and EL performance by supporting this proton acceptor functional group on the resin is not necessarily clear, but is estimated as follows. . That is, as described above, the proton acceptor functional group is a group capable of electrostatically interacting with protons or a functional group having a lone electron pair, and neutralizes by quenching the acid, or The acid can be trapped by the interaction with the acid without causing the sum to suppress the movement of the acid. For this reason, the proton acceptor functional group neutralizes or traps excess acid that has moved from the resist surface layer to the topcoat layer in the topcoat layer. On the other hand, since there is no movement of the proton acceptor functional group from the topcoat layer to the resist layer, the acid generated in the exposed portion of the resist layer can be used as it is to maintain the function related to pattern formation. As a result, it is presumed that the pattern can be prevented from becoming a T-top shape, the DOF and EL performance can be improved, and the LER can be reduced by suppressing film loss.

The proton acceptor functional group contained in the resin (X) will be described in more detail.
As described above, the proton acceptor functional group is a group capable of electrostatically interacting with a proton or a functional group having a lone pair of electrons, such as a functional group having a macrocyclic structure such as a cyclic polyether. And a functional group having a nitrogen atom having a lone electron pair with little contribution of π conjugation, an ether bond, a thioether bond, a carbonyl bond, and a thiocarbonyl bond.

Examples of the nitrogen atom having a lone electron pair with little contribution of π conjugation include a nitrogen atom having a partial structure represented by the following general formula.

In one form, the proton acceptor functional group includes a nitrogen atom constituting a primary amine, a secondary amine, or a tertiary amine (eg, aliphatic amines, aromatic amines, heterocyclic amines). It is preferable that it is a functional group to contain. Moreover, it is preferable that a proton acceptor functional group is an ether bond, a thioether bond, a carbonyl bond, or a thiocarbonyl bond in another form.

Primary, secondary or tertiary aliphatic amines, aromatic amines, or heterocyclic amines containing such proton acceptor functional groups, ether bonds, thioether bonds, carbonyl bonds, or The carbon number of a structure containing a proton acceptor functional group such as a thiocarbonyl bond is preferably 4 to 30. Examples of the group including such a structure include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group.

The alkyl group may have a substituent, and is preferably a linear or branched alkyl group having 1 to 30 carbon atoms, and may have an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain. Good. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group, etc. And branched alkyl groups such as a linear alkyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, and 2-ethylhexyl group.

The cycloalkyl group may have a substituent, preferably a cycloalkyl group having 3 to 20 carbon atoms, and may have an oxygen atom or a nitrogen atom in the ring. Specific examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.

The aryl group may have a substituent and is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group and a naphthyl group.

The aralkyl group may have a substituent, and preferably an aralkyl group having 7 to 20 carbon atoms, for example, a benzyl group, a phenethyl group, a naphthylmethyl group, or a naphthylethyl group.

The alkenyl group may have a substituent, and examples thereof include a group having a double bond at an arbitrary position of the alkyl group.

Examples of the substituent that each group may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), an aryl group (preferably Has 6 to 14 carbon atoms, an alkoxy group (preferably 1 to 10 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 10 carbon atoms), an alkoxycarbonyl group (preferably And an aminoacyl group (preferably having a carbon number of 2 to 20). As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 20). As for the aminoacyl group, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 20).

The proton acceptor functional group may be substituted with a group capable of decomposing and leaving by the action of an acid (hereinafter also referred to as “acid-decomposable group”). Examples of the acid-decomposable group include an amide group, an ester group (preferably a tertiary alkyloxycarbonyl group), an acetal group (preferably a 1-alkyloxy-alkyloxy group), a carbamoyl group, and a carbonate group. Can be mentioned.

Further, the proton acceptor functional group may be introduced into the resin (X) in a form contained in the side chain of the repeating unit, or included in the terminal structure bonded to the main chain of the resin (X). It may be introduced in the form.

When the resin (X) includes a repeating unit having a proton acceptor functional group, the content of the repeating unit is 0.1 to 10 mol% with respect to all the repeating units in the resin (X). Is preferable, and more preferably 0.5 to 5 mol%.

In one embodiment of the present invention, the proton acceptor functional group preferably contains a nitrogen atom.

However, when the composition of the present invention is particularly for ArF exposure, the proton acceptor functional group containing the nitrogen atom may not have aromaticity from the viewpoint of transparency to ArF light. Preferably, it does not have a nitrogen-containing aromatic ring, and more preferably.

Examples of the proton acceptor functional group containing a nitrogen atom include basic groups represented by any of the following general formulas (A) to (E).

In general formula (A), R ²⁰¹ and R ²⁰² each independently represents a hydrogen atom, an alkyl group (preferably having a carbon number of 1 to 20), a cycloalkyl group (preferably having a carbon number of 3 to 20), or an aryl group ( Preferably, it represents 6 to 20 carbon atoms.

In general formula (E), R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ are each independently an alkyl group (preferably having 1 to 20 carbon atoms) or a cycloalkyl group (preferably having 3 to 20 carbon atoms). Represents.

* Represents a bond bonded to another atom constituting the structure (I).

In the structure represented by the general formula (A), R ²⁰¹ and R ²⁰² may be bonded to each other to form a ring.

In the structures represented by the general formulas (B) to (D), two or more of a bond from a carbon atom and a bond from a nitrogen atom may be bonded to each other to form a ring.

In the structure represented by the general formula (E), two or more of R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ , R ²⁰⁶ , a bond from a carbon atom, and a bond from a nitrogen atom are bonded to each other, A ring may be formed. In the general formula (A), the alkyl group of R ²⁰¹ and R ²⁰² is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, i-propyl group, i-butyl group, sec-butyl group, Examples thereof include t-butyl group and t-dodecyl group.

The cycloalkyl group represented by R ²⁰¹ and R ²⁰² is preferably a cycloalkyl group having 3 to 20 carbon atoms, and examples thereof include a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

Of the alkyl groups and cycloalkyl groups represented by R ²⁰¹ and R ^202, a linear alkyl group having 1 to 10 carbon atoms and a cycloalkyl group having 4 to 8 carbon atoms are preferable.

The aryl group of R ²⁰¹ and R ²⁰² is preferably an aryl group having 6 to 20 carbon atoms, and examples thereof include a phenyl group, a toluyl group, a benzyl group, a methylbenzyl group, a xylyl group, a mesityl group, a naphthyl group, and an anthryl group. It is done.

The alkyl group, cycloalkyl group and aryl group of R ²⁰¹ and R ²⁰² may further have a substituent. Examples of such a substituent include a halogen atom, a hydroxyl group, an amino group, a carboxyl group, cyano Group, nitro group, alkyl group, cycloalkyl group, aryl group, alkoxy group, aryloxy group, acyl group, arylcarbonyl group, alkoxyalkyl group, aryloxyalkyl group, alkylcarbonyloxy group, arylcarbonyloxy group, alkoxycarbonyl Group, aryloxycarbonyl group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, lactone group and the like.

In General Formula (E), specific examples of the alkyl group and cycloalkyl group of R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ are the same as the specific examples of the alkyl group and cycloalkyl group of R ²⁰¹ and R ²⁰² , respectively. is there.

The alkyl group and cycloalkyl group of R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may further have a substituent, and specific examples of such a substituent are further included in R ²⁰¹ and R ^202. The same as the above specific examples of the substituents that may be present.

In the groups represented by the general formulas (A) to (E), a bond from a carbon atom and / or a nitrogen atom is bonded to another atom constituting the structure (I).

Further, as described above, in the group represented by the general formula (A), R ²⁰¹ and R ²⁰² may be bonded to each other to form a ring, and represented by the general formulas (B) to (D). In the group represented by formula (E), two or more of the bond from the carbon atom and the bond from the nitrogen atom may be bonded to each other to form a ring. , R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ , R ²⁰⁶ , two or more of a bond from a carbon atom and a bond from a nitrogen atom may be bonded to each other to form a ring.

Examples of the ring include aromatic or non-aromatic nitrogen-containing heterocycles. Examples of such nitrogen-containing heterocycles include 3- to 10-membered rings, preferably 4- to 8-membered rings, and more preferably 5- or 6-membered rings. Such a ring may further have a substituent, and specific examples thereof are the same as the specific examples described above as substituents which R ²⁰¹ and R ²⁰² may further have.

Examples of the proton acceptor functional group containing a nitrogen atom include a nitrogen atom constituting a primary, secondary or tertiary aliphatic amine, aromatic amine, or heterocyclic amine. The functional group to include is mentioned.

Examples of the aliphatic amines include ethylamine, n-propylamine, sec-butylamine, tert-butylamine, hexylamine, cyclohexylamine, octylamine, dodecylamine, ethylenediamine, tetraethylenepentamine, dimethylamine, diethylamine, and di-n. -Propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, dipentylamine, dihexylamine, dicyclohexylamine, dioctylamine, didodecylamine, N, N-dimethylethylenediamine, N, N-dimethyl Tetraethylenepentamine, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutyl Min, tri-sec-butylamine, tripentylamine, trihexylamine, tricyclohexylamine, triheptylamine, trioctylamine, tridecylamine, tridodecylamine, N, N, N ′, N′-tetramethylmethylenediamine N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethyltetraethylenepentamine, dimethylethylamine, methylethylpropylamine, benzylamine, phenethylamine, benzyldimethylamine, mono Ethanolamine, diethanolamine, triethanolamine, N-ethyldiethanolamine, N, N-diethylethanolamine, triisopropanolamine, 2-aminoethanol, 3-amino-1-propanol, 4-amino- - butanol and the like.

Examples of the aromatic amines and the heterocyclic amines include aniline derivatives, diphenyl (p-tolyl) amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole derivatives, oxazole derivatives, thiazole derivatives, imidazoles. Derivatives, pyrazole derivatives, furazane derivatives, pyrroline derivatives, pyrrolidine derivatives, imidazoline derivatives, imidazolidine derivatives, pyridine derivatives (preferably 2- (2-hydroxyethyl) pyridine), pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine Derivatives, piperidine derivatives, piperazine derivatives (preferably 1- (2-hydroxyethyl) piperazine, 1- [2- (2-hydroxyethoxy) ethyl Piperazine), morpholine derivatives (preferably 4- (2-hydroxyethyl) morpholine), indole derivatives, isoindole derivatives, 1H-indazole derivatives, indoline derivatives, quinoline derivatives, isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxaline derivatives, Examples include phthalazine derivatives, purine derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenazine derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine derivatives, guanine derivatives, guanosine derivatives, uracil derivatives, uridine derivatives, etc. Is done.

The proton acceptor functional group containing a nitrogen atom may be substituted with a group capable of decomposing and leaving by the action of an acid (acid-decomposable group). For example, a form in which the proton acceptor functional group represented by any one of the above general formulas (A) to (E) is substituted with an acid-decomposable group is preferred, and more preferred is represented by the following general formula (Ap). Can be mentioned.

In general formula (Ap):
Ra, Rb ₁ , Rb ₂ and Rb ₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group. Two of Rb ₁ to Rb ₃ may be bonded to each other to form a ring. However, all of Rb ₁ to Rb ₃ do not become hydrogen atoms at the same time.

Rc represents a single bond or a divalent linking group.

X represents 0 or 1, y represents 1 or 2, and x + y = 2.

When x = 1, Ra and Rc may be bonded to each other to form a nitrogen-containing heterocycle.

Specific examples of the alkyl group, cycloalkyl group and aryl group as Ra, Rb ₁ , Rb ₂ and Rb ₃ are the alkyl group and cycloalkyl group of R ²⁰¹ and R ^{202 in} the group represented by the general formula (A). And the same as the above specific examples of the aryl group.

Specific examples of the aralkyl group as Ra, Rb ₁ , Rb ₂ and Rb ₃ are preferably aralkyl groups having 6 to 12 carbon atoms, such as benzyl group, phenethyl group, naphthylmethyl group, naphthylethyl group, naphthylbutyl group, etc. Can be mentioned.

Ra, Rb ₁ , Rb ₂ and Rb ₃ are preferably a linear or branched alkyl group, a cycloalkyl group or an aryl group. More preferably, it is a linear or branched alkyl group or cycloalkyl group.

Rc is preferably a divalent linking group having 2 to 12 carbon atoms (more preferably 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms), such as an alkylene group, a phenylene group, an ether group, Examples include an ester group, an amide group, and a group formed by combining two or more of these.

Each of Ra, Rb ₁ , Rb ₂ , Rb ₃ and Rc may further have a substituent. Specific examples of such a substituent include, for example, a halogen atom (such as a fluorine atom), a hydroxyl group, nitro Group, cyano group, carboxy group, carbonyl group, cycloalkyl group (preferably having 3 to 10 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), alkoxy group (preferably having 1 to 10 carbon atoms), acyl group (Preferably 2 to 20 carbon atoms), acyloxy group (preferably 2 to 10 carbon atoms), alkoxycarbonyl group (preferably 2 to 20 carbon atoms), aminoacyl group (preferably 2 to 10 carbon atoms), amino group, Examples thereof include a pyrrolidino group, a piperidino group, a morpholino group, and a group having a silicon atom. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having 1 to 10 carbon atoms). As for the aminoacyl group, examples of the substituent further include an alkyl group (preferably having 1 to 10 carbon atoms).

When _{two of} Rb ₁ , Rb ₂ and Rb ₃ are both hydrogen atoms, the remaining one is preferably an aryl group, and examples of the aryl group include a phenyl group and a naphthyl group. .

In addition, examples of the nitrogen-containing heterocycle formed by bonding Ra and Rc to each other include aromatic or non-aromatic nitrogen-containing heterocycles (preferably having 3 to 20 carbon atoms). Examples of such nitrogen-containing heterocycle include pyrrolidine, piperidine, morpholine, 1,4,5,6-tetrahydropyrimidine, 1,2,3,4-tetrahydroquinoline, 1,2,3,6-tetrahydropyridine. , Homopiperazine, 4-azabenzimidazole, benzotriazole, 5-azabenzotriazole, 1H-1,2,3-triazole, 1,4,7-triazacyclononane, tetrazole, 7-azaindole, indazole, benz Imidazole, imidazo [1,2-a] pyridine, (1S, 4S)-(+)-2,5-diazabicyclo [2.2.1] heptane, 1,5,7-triazabicyclo [4.4. 0] Deck-5-ene, indole, indoline, 1,2,3,4-tetrahydroquinoxaline, perhydroquinoline, Include a ring corresponding to the heterocyclic compounds such as 5,9-triazacyclododecane.

The ring formed by combining two of Rb ₁ to Rb ₃ includes a cyclopentane ring, a monocyclic cycloalkane ring such as a cyclohexane ring, a norbornane ring, a tetracyclodecane ring, a tetracyclododecane ring, an adamantane ring A polycyclic cycloalkane ring such as is preferable. A monocyclic cycloalkane ring having 5 to 6 carbon atoms is particularly preferred.

The nitrogen-containing heterocyclic ring formed by combining Ra and Rc with each other and the ring formed by combining two of Rb ₁ to Rb ₃ each further contain one or more substituents or one substituent. Specific examples of such substituents that may be included are the same as specific examples of the substituent that Ra, Rb ₁ , Rb ₂ , Rb ₃ and Rc may further have.

The group represented by the general formula (Ap) can be easily synthesized by a method described in Protective Groups in Organic Synthesis 4th edition or the like with respect to a group having a general amine structure. As the most general method, there is a method obtained by allowing a dicarbonate ester or a haloformate ester to act on a group having an amine structure. In the formula, X represents a halogen atom. _{Ra, Rb 1, Rb 2,} Rb 3, Rc , respectively, the same meanings as _{Ra, Rb 1, Rb 2,} Rb 3, Rc in formula (Ap).

The proton acceptor functional group containing a nitrogen atom may be introduced into the resin (X) in a form contained in the side chain of the repeating unit (I), or in the main chain of the resin (X). It may be introduced in a form contained in the bound terminal structure.

The repeating unit (I) having a proton acceptor functional group containing a nitrogen atom in the side chain is a proton acceptor functional group containing a nitrogen atom as at least one polymerizable component in the synthesis of the resin (X). It can obtain by using the monomer (1) provided with.

The terminal structure having a proton acceptor functional group containing a nitrogen atom and bonded to the main chain of the resin (X) is a proton acceptor containing a nitrogen atom as a chain transfer agent in the synthesis of the resin (X). By using the compound (2) having a functional group, or by using the compound (3) having a proton acceptor functional group containing a nitrogen atom as a polymerization initiator in the synthesis of the resin (X). ,Obtainable.

Examples of the repeating unit corresponding to the monomer (1) having a proton acceptor functional group containing a nitrogen atom include repeating units represented by the following general formulas (P1) to (P3).

In general formulas (P1) to (P3),
X ₁ represents a hydrogen atom or an alkyl group.

X ₂ represents a single bond or a divalent linking group.

R ₁ represents a structure containing a proton acceptor functional group containing a nitrogen atom.

R ₂ represents a hydrogen atom or an alkyl group.

R ₁ and R ₂ may be connected to each other to form a ring.

In the general formulas (P1) to (P3), the alkyl group of X ₁ and R ₂ is preferably an alkyl group having 1 to 10 carbon atoms and may be substituted with a fluorine atom, a chlorine atom, a hydroxyl group or the like.

Examples of the divalent linking group for X ₂ include an alkylene group, an arylene group, an oxy group, and a carbonyl group, and combinations of two or more thereof.

Examples of the structure containing a proton acceptor functional group containing a nitrogen atom of R ₁ include those listed above as structures containing a proton acceptor functional group containing a nitrogen atom.

Specific examples of the repeating unit corresponding to the monomer (1) having a proton acceptor functional group containing a nitrogen atom include the repeating units represented by the following general formulas (P4) to (P10). be able to.

In the general formulas (P4) to (P10),
X ₁ has the same meaning as _{X 1} in the general formula (P1).

R ₃ to R ₉ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or an aralkyl group. R ₃ and R ₄ may be connected to each other to form a ring. R ₅ and R ₆ and R ₇ and R ₈ may be connected to each other to form a ring (preferably an aromatic ring).

Z represents an alkylene group or —NH—.

The alkyl group of R ₃ to R ₉ is preferably an alkyl group having 1 to 10 carbon atoms, the cycloalkyl group is preferably a cycloalkyl group having 1 to 20 carbon atoms, and the alkenyl group is 1 to 10 carbon atoms. The aryl group is preferably an aryl group having 6 to 20 carbon atoms, the aralkyl group is preferably an aralkyl group having 7 to 20 carbon atoms, and these groups include a fluorine atom, a chlorine atom, a hydroxyl group, and a carbonyl group. Group, cyano group, sulfone group and the like.

Hereinafter, specific examples of the repeating unit corresponding to the monomer (1) having a proton acceptor functional group containing a nitrogen atom will be given, but the present invention is not limited thereto.

Corresponding to a monomer (1) having a proton acceptor functional group containing a nitrogen atom, wherein the proton acceptor functional group containing a nitrogen atom is substituted with an acid-decomposable group Examples of the repeating unit include the repeating units represented by the following general formulas (P′1) to (P′3).

In general formulas (P′1) to (P′3),
X ₁ represents a hydrogen atom or an alkyl group.

X ₂ represents a single bond or a divalent linking group.

R ₂ represents a hydrogen atom or an alkyl group.

R ₃ represents a structure including a proton acceptor functional group containing a nitrogen atom, which is substituted with an acid-decomposable group.

R ₁ and R ₂ may be connected to each other to form a ring.

In general formulas (P′1) to (P′3), the alkyl group of X ₁ and R ₂ is preferably an alkyl group having 1 to 10 carbon atoms, and is substituted with a fluorine atom, a chlorine atom, a hydroxyl group, or the like. Also good. Examples of the divalent linking group for X ₂ include an alkylene group, an arylene group, an oxy group, and a carbonyl group, and combinations of two or more thereof.

Examples of the proton acceptor functional group containing a nitrogen atom, which is substituted by an acid-decomposable group, in the structure represented by R ₃ include those listed above.

Hereinafter, although the specific example of the repeating unit corresponding to the monomer (1 ') which has the proton acceptor functional group containing the nitrogen atom substituted by the acid-decomposable group is given, this invention is limited to this. It is not a thing.

In the following specific examples, Rx represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

As described above, the proton acceptor functional group is preferably an ether bond, a thioether bond, a carbonyl bond, or a thiocarbonyl bond.

In one embodiment of the present invention, the resin (X) preferably contains a repeating unit containing an ether bond. The repeating unit including an ether bond preferably includes, for example, two or more ether bonds, more preferably includes three or more ether bonds, and further preferably includes four or more ether bonds.

In one embodiment of the present invention, the resin (X) preferably contains a repeating unit containing an oxyalkylene structure represented by the following general formula (1).

Where
R ₁₁ represents an alkylene group which may have a substituent.
n represents an integer of 2 or more.
* Represents a bond.

The number of carbon atoms of the alkylene group represented by R ₁₁ in the general formula (1) is not particularly limited, but is preferably 1 to 15, more preferably 1 to 5, and preferably 2 or 3. More preferably, 2 is particularly preferable. When this alkylene group has a substituent, the substituent is not particularly limited, but is preferably an alkyl group (preferably having 1 to 10 carbon atoms).

N is preferably an integer of 2 to 20, and more preferably 10 or less for the reason that DOF becomes larger.

The average value of n is preferably 20 or less, more preferably 2 to 10, more preferably 2 to 8, and particularly preferably 4 to 6 because the DOF becomes larger. preferable. Here, the “average value of n” means the value of n determined so that the weight average molecular weight of the resin (X) is measured by GPC and the obtained weight average molecular weight matches the general formula. If n is not an integer, round it off.
A plurality of R ₁₁ may be the same or different.

The repeating unit having the partial structure represented by the general formula (1) may be a repeating unit having a partial structure represented by the following general formula (1-1) because the DOF becomes larger. preferable.

Where
R ₁₁ represents an alkylene group which may have a substituent.

R ₁₂ represents a hydrogen atom or an alkyl group.

M represents an integer of 1 or more.

* Represents a bond.

Specific examples of the alkyl group represented by R _11, and preferred embodiments are the same as R ₁₁ in general formula (1).

The number of carbon atoms of the alkyl group represented by R ₁₂ is not particularly limited, but is preferably 1-15.

m is preferably an integer of 1 to 20, and among them, it is more preferably 10 or less for the reason that DOF becomes larger.
The average value of m is preferably 20 or less, more preferably 1 to 10, more preferably 1 to 8, and particularly preferably 4 to 6 because the DOF becomes larger. preferable. Here, the “average value of m” is synonymous with the “average value of n” described above.

When m is 2 or more, a plurality of R ₁₁ may be the same or different.

A structure including a partial structure of an ether bond, a thioether bond, a carbonyl bond, or a thiocarbonyl bond, which is a proton acceptor functional group, is introduced into the resin (X) in a form contained in the side chain of the repeating unit. Alternatively, it may be introduced in a form contained in the terminal structure bonded to the main chain of the resin (X).

When these groups are contained in the repeating unit, preferred repeating units include, for example, repeating units represented by the following general formulas (P11), (P12), and (P13).

In general formulas (P11) to (P13),
X ₁ represents a hydrogen atom or an alkyl group.
X ₂ represents a single bond or a divalent linking group.
R ₁₁ represents an organic group containing an ether bond, a thioether bond, a carbonyl bond, or a thiocarbonyl bond.
R ₂ represents a hydrogen atom or an alkyl group.
R ₁ and R ₂ may be connected to each other to form a ring.

The definitions, specific examples and preferred embodiments of X ₁ , X ₂ and R ₂ are the same as those in the general formulas (P1) to (P3) described above.
The organic group represented by R ₁₁ is preferably an organic group having 4 to 30 carbon atoms including, for example, an ether bond, a thioether bond, a carbonyl bond, or a thiocarbonyl bond.

When the organic group represented by R ₁₁ has an ether bond, R ₁₁ is preferably a partial structure represented by the above general formula (1), and a moiety represented by the above general formula (1-1) A structure is more preferable.

Specific examples of repeating units having a proton acceptor functional group are shown below. *

Also, as described above, the proton acceptor functional group may be introduced in a form contained in the terminal structure bonded to the main chain of the resin (X).

The terminal structure having a proton acceptor functional group bonded to the main chain of the resin (X) is obtained by using a compound having a proton acceptor functional group as a chain transfer agent in the synthesis of the resin (X). Alternatively, it can be obtained by using a compound having a proton acceptor functional group as a polymerization initiator in the synthesis of the resin (X).

Resin (X) in which a proton acceptor functional group containing a nitrogen atom is introduced into the terminal structure bonded to the main chain of the resin can be obtained according to the method described in paragraphs 0077 to 0108 of JP2013-218223A. be able to.

The resin (X) that can be suitably used for the composition for forming a protective film is preferably transparent in the exposure light source used because light reaches the actinic ray-sensitive or radiation-sensitive film through the protective film during exposure. . When used for ArF immersion exposure, the resin (X) preferably has no aromatic group from the viewpoint of transparency to ArF light.

In one embodiment of the present invention, the resin (X) is preferably a resin that does not substantially contain a fluorine atom. Specifically, the fluorine atom content in the resin (X) is preferably 20% by mass or less, more preferably 10% by mass or less, ideally substantially with respect to the weight average molecular weight of the resin (X). It means 0 mass%.

In another embodiment of the present invention, the resin (X) is preferably a resin having a CH ₃ partial structure in the side chain portion.
Here, the CH ₃ partial structure of the side chain portion in the resin (X) (hereinafter also simply referred to as “side chain CH ₃ partial structure”) includes the CH ₃ partial structure of an ethyl group, a propyl group, or the like. Is.

On the other hand, a methyl group directly bonded to the main chain of the resin (X) (for example, an α-methyl group of a repeating unit having a methacrylic acid structure) is not included in the CH ₃ partial structure in the present invention.

More specifically, the resin (X) includes a repeating unit derived from a monomer having a polymerizable moiety having a carbon-carbon double bond, such as a repeating unit represented by the following general formula (M). In the case where R ₁₁ to R ₁₄ are CH ₃ “as is”, the CH ₃ is not included in the CH ₃ partial structure of the side chain moiety in the present invention.

Meanwhile, CH ₃ partial structure exists through some atoms from C-C backbone, and those falling under CH ₃ partial structures in the present invention. For example, when R ₁₁ is an ethyl group (CH ₂ CH ₃ ), it is assumed that it has “one” CH ₃ partial structure in the present invention.

In the general formula (M),
R ₁₁ to R ₁₄ each independently represents a side chain portion.

Examples of R ₁₁ to R _{14 in the} side chain portion include a hydrogen atom and a monovalent organic group.

Examples of the monovalent organic group for R ₁₁ to R ₁₄ include an alkyl group, a cycloalkyl group, an aryl group, an alkyloxycarbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an alkylaminocarbonyl group, and a cycloalkylaminocarbonyl. Group, an arylaminocarbonyl group, and the like, and these groups may further have a substituent.

The resin (X) is preferably a resin having a repeating unit having a CH ₃ partial structure in the side chain portion. As such a repeating unit, the repeating unit represented by the following general formula (II), and the following It is more preferable to have at least one repeating unit (x) among the repeating units represented by the general formula (III). In particular, when KrF, EUV, or electron beam (EB) is used as the exposure light source, the resin (X) can suitably contain a repeating unit represented by the general formula (III).
Hereinafter, the repeating unit represented by formula (II) will be described in detail.

In the general formula (II), X _b1 represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom, R ₂ has one or more CH ₃ partial structure represents a stable organic radical to acid. Here, more specifically, the organic group that is stable to acid is decomposed by the action of “acid” described in the acid-decomposable resin contained in the actinic ray-sensitive or radiation-sensitive resin composition described later. It is preferable that the organic group does not have a group that generates an alkali-soluble group.

The alkyl group of _Xb1 preferably has 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a trifluoromethyl group, and a methyl group is preferable.

X _b1 is preferably a hydrogen atom or a methyl group.

Examples of R ₂ include an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, and an aralkyl group having one or more CH ₃ partial structures. The above cycloalkyl group, alkenyl group, cycloalkenyl group, aryl group, and aralkyl group may further have an alkyl group as a substituent.

R ₂ is preferably an alkyl group or an alkyl-substituted cycloalkyl group having one or more CH ₃ partial structures.

The acid-stable organic group having one or more CH ₃ partial structures as R ₂ preferably has 2 or more and 10 or less CH ₃ partial structures, and more preferably 2 or more and 8 or less.

The alkyl group having one or more CH ₃ partial structures in R ₂ is preferably a branched alkyl group having 3 to 20 carbon atoms. Specific examples of preferable alkyl groups include isopropyl group, isobutyl group, 3-pentyl group, 2-methyl-3-butyl group, 3-hexyl group, 2-methyl-3-pentyl group, and 3-methyl-4. -Hexyl, 3,5-dimethyl-4-pentyl, isooctyl, 2,4,4-trimethylpentyl, 2-ethylhexyl, 2,6-dimethylheptyl, 1,5-dimethyl-3-heptyl Group, 2,3,5,7-tetramethyl-4-heptyl group and the like. More preferably, an isobutyl group, a t-butyl group, a 2-methyl-3-butyl group, a 2-methyl-3-pentyl group, a 3-methyl-4-hexyl group, a 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4-heptyl group is there.

The cycloalkyl group having one or more CH ₃ partial structures in R ₂ may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The number of carbon atoms is preferably 6-30, and particularly preferably 7-25. Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, A cyclodecanyl group and a cyclododecanyl group can be mentioned. More preferable examples include an adamantyl group, norbornyl group, cyclohexyl group, cyclopentyl group, tetracyclododecanyl group, and tricyclodecanyl group. More preferably, they are a norbornyl group, a cyclopentyl group, and a cyclohexyl group.

The alkenyl group having one or more CH ₃ partial structures in R ₂ is preferably a linear or branched alkenyl group having 1 to 20 carbon atoms, and more preferably a branched alkenyl group.

The aryl group having one or more CH ₃ partial structures in R ₂ is preferably an aryl group having 6 to 20 carbon atoms, and examples thereof include a phenyl group and a naphthyl group. is there.

The aralkyl group having one or more CH ₃ partial structures in R ₂ is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.

Specific examples of the hydrocarbon group having two or more CH ₃ partial structures in R ₂ include isopropyl group, isobutyl group, t-butyl group, 3-pentyl group, 2-methyl-3-butyl. Group, 3-hexyl group, 2,3-dimethyl-2-butyl group, 2-methyl-3-pentyl group, 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, isooctyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4-heptyl group, Examples include 3,5-dimethylcyclohexyl group, 4-isopropylcyclohexyl group, 4-tbutylcyclohexyl group, and isobornyl group. More preferably, an isobutyl group, t-butyl group, 2-methyl-3-butyl group, 2,3-dimethyl-2-butyl group, 2-methyl-3-pentyl group, 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5 , 7-tetramethyl-4-heptyl group, 3,5-dimethylcyclohexyl group, 3,5-ditert-butylcyclohexyl group, 4-isopropylcyclohexyl group, 4-tbutylcyclohexyl group and isobornyl group.

Preferred specific examples of the repeating unit represented by the general formula (II) are listed below. Note that the present invention is not limited to this.

The repeating unit represented by the general formula (II) is preferably an acid-stable (non-acid-decomposable) repeating unit, and specifically, a group that decomposes by the action of an acid to generate a polar group. It is preferable that it is a repeating unit which does not have.

Hereinafter, the repeating unit represented by the general formula (III) will be described in detail.

In the above general formula (III), X _b2 represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom, R ₃ represents an acid-stable organic group having one or more CH ₃ partial structures, n represents an integer of 1 to 5.

The alkyl group of _Xb2 is preferably an alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a trifluoromethyl group, and a hydrogen atom is preferable.

X _b2 is preferably a hydrogen atom.

R ₃ is an organic group that is stable to acid, and more specifically, does not have a “group that decomposes by the action of an acid to generate an alkali-soluble group”, which will be described later in the acid-decomposable resin. An organic group is preferred.

R ₃ includes an alkyl group having one or more CH ₃ partial structures.

The acid-stable organic group having one or more CH ₃ partial structures as R ₃ preferably has 1 or more and 10 or less CH ₃ partial structures, more preferably 1 or more and 8 or less, More preferably, it is 1 or more and 4 or less.

The alkyl group having one or more CH ₃ partial structures in R ₃ is preferably a branched alkyl group having 3 to 20 carbon atoms. Specific examples of preferable alkyl groups include isopropyl group, isobutyl group, 3-pentyl group, 2-methyl-3-butyl group, 3-hexyl group, 2-methyl-3-pentyl group, and 3-methyl-4. -Hexyl, 3,5-dimethyl-4-pentyl, isooctyl, 2,4,4-trimethylpentyl, 2-ethylhexyl, 2,6-dimethylheptyl, 1,5-dimethyl-3-heptyl Group, 2,3,5,7-tetramethyl-4-heptyl group and the like. More preferably, an isobutyl group, a t-butyl group, a 2-methyl-3-butyl group, a 2-methyl-3-pentyl group, a 3-methyl-4-hexyl group, a 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4-heptyl group is there.

Specific examples of the alkyl group having two or more CH ₃ partial structures in R ₃ include isopropyl group, isobutyl group, t-butyl group, 3-pentyl group, 2,3-dimethylbutyl group, 2-methyl-3-butyl group, 3-hexyl group, 2-methyl-3-pentyl group, 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, isooctyl group, 2,4, 4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4-heptyl group, etc. . More preferably, it has 5 to 20 carbon atoms, and is an isopropyl group, t-butyl group, 2-methyl-3-butyl group, 2-methyl-3-pentyl group, or 3-methyl-4-hexyl group. 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3, 5,7-tetramethyl-4-heptyl group and 2,6-dimethylheptyl group.

N represents an integer of 1 to 5, more preferably an integer of 1 to 3, and still more preferably 1 or 2.

Preferred specific examples of the repeating unit represented by the general formula (III) are given below. Note that the present invention is not limited to this.

The repeating unit represented by the general formula (III) is preferably an acid-stable (non-acid-decomposable) repeating unit, and specifically, a group that decomposes by the action of an acid to generate a polar group. It is preferable that it is a repeating unit which does not have.

In the case where the resin (X) contains a CH ₃ partial structure in the side chain portion, and particularly when it does not have a fluorine atom and a silicon atom, the repeating unit represented by the general formula (II) and the general formula The content of at least one repeating unit (x) among the repeating units represented by (III) is preferably 90 mol% or more and 95 mol% or more with respect to all repeating units of the resin (X). It is more preferable that Content of repeating unit (x) is 100 mol% or less normally with respect to all the repeating units of resin (X).

Resin (X) is a repeating unit represented by general formula (II), and at least one repeating unit (x) among repeating units represented by general formula (III) By containing 90 mol% or more with respect to the unit, the surface free energy of the resin (X) increases. As a result, the resin (X) is less likely to be unevenly distributed on the surface of the actinic ray-sensitive or radiation-sensitive composition film, and the static / dynamic contact angle of the actinic ray-sensitive or radiation-sensitive film with respect to water is ensured. It is possible to improve the immersion liquid followability.

In another embodiment of the present invention, the resin (X) is preferably a resin containing a repeating unit derived from a monomer containing at least one fluorine atom and / or at least one silicon atom. More preferably, it is a water-insoluble resin containing a repeating unit derived from a monomer containing one fluorine atom and / or at least one silicon atom. By containing a repeating unit derived from a monomer containing at least one fluorine atom and / or at least one silicon atom, good solubility in an organic solvent developer can be obtained, and the effects of the present invention can be sufficiently obtained. .

The fluorine atom or silicon atom in the resin (X) may be contained in the main chain of the resin or may be substituted with a side chain.

The resin (X) is preferably a resin having an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom as a partial structure having a fluorine atom.

The alkyl group having a fluorine atom (preferably having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms) is a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, It may have a substituent.

The cycloalkyl group having a fluorine atom is a monocyclic or polycyclic cycloalkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and may further have another substituent.

Examples of the aryl group having a fluorine atom include those in which at least one hydrogen atom of an aryl group such as a phenyl group or a naphthyl group is substituted with a fluorine atom, and may further have another substituent.

Specific examples of the alkyl group having a fluorine atom, the cycloalkyl group having a fluorine atom, or the aryl group having a fluorine atom are shown below, but the present invention is not limited thereto.

In general formulas (F2) to (F3),
R ₅₇ to R ₆₄ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R ₅₇ to R ₆₁ and R ₆₂ to R ₆₄ represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having 1 to 4 carbon atoms). R ₅₇ to R ₆₁ are preferably all fluorine atoms. R ₆₂ and R ₆₃ are preferably an alkyl group (preferably having 1 to 4 carbon atoms) in which at least one hydrogen atom is substituted with a fluorine atom, and more preferably a perfluoroalkyl group having 1 to 4 carbon atoms. R ₆₂ and R ₆₃ may be connected to each other to form a ring.

Specific examples of the group represented by the general formula (F2) include a p-fluorophenyl group, a pentafluorophenyl group, and a 3,5-di (trifluoromethyl) phenyl group.

Specific examples of the group represented by the general formula (F3) include trifluoroethyl group, pentafluoropropyl group, pentafluoroethyl group, heptafluorobutyl group, hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2 -Methyl) isopropyl group, nonafluorobutyl group, octafluoroisobutyl group, nonafluorohexyl group, nonafluoro-t-butyl group, perfluoroisopentyl group, perfluorooctyl group, perfluoro (trimethyl) hexyl group, 2,2 1,3,3-tetrafluorocyclobutyl group, perfluorocyclohexyl group and the like. Hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, octafluoroisobutyl group, nonafluoro-t-butyl group and perfluoroisopentyl group are preferable, and hexafluoroisopropyl group and heptafluoroisopropyl group are preferable. Further preferred.

Resin (X) is preferably a resin having an alkylsilyl structure (preferably a trialkylsilyl group) or a cyclic siloxane structure as a partial structure having a silicon atom.

Specific examples of the alkylsilyl structure or the cyclic siloxane structure include groups represented by the following general formulas (CS-1) to (CS-3).

In general formulas (CS-1) to (CS-3),
R ₁₂ to R ₂₆ each independently represents a linear or branched alkyl group (preferably having 1 to 20 carbon atoms) or a cycloalkyl group (preferably having 3 to 20 carbon atoms).

L ₃ to L _{5 each} represents a single bond or a divalent linking group. As the divalent linking group, an alkylene group, a phenyl group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group, or a urea group is used alone or in combination of two or more groups. A combination is mentioned.

N represents an integer from 1 to 5.

Examples of the resin (X) include resins having at least one selected from the group of repeating units represented by the following general formulas (CI) to (CV).

In the general formulas (CI) to (CV),
R ₁ to R ₃ each independently represents a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms. Represents a group.

W ₁ and W ₂ represent an organic group having at least one of a fluorine atom and a silicon atom.

R ₄ to R ₇ are each independently a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms. Represents a group. However, at least one of R ₄ to R ₇ represents a fluorine atom. R ₄ and R ₅ or R ₆ and R ₇ may form a ring.

R ₈ represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.

R ₉ represents a linear or branched alkyl group having 1 to 4 carbon atoms or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms.

L ₁ and L ₂ represent a single bond or a divalent linking group, and are the same as L ₃ to L ₅ described above.

Q represents a monocyclic or polycyclic cycloaliphatic group. That is, it represents an atomic group that contains two bonded carbon atoms (C—C) and forms an alicyclic structure.

R ₃₀ and R ₃₁ each independently represents a hydrogen atom or a fluorine atom.

R ₃₂ and R ₃₃ each independently represents an alkyl group, a cycloalkyl group, a fluorinated alkyl group or a fluorinated cycloalkyl group.

However, the repeating unit represented by the general formula (CV) has at least one fluorine atom in at least one of R ₃₀ , R ₃₁ , R ₃₂ and R ₃₃ .

The resin (X) preferably has a repeating unit represented by the general formula (CI), and further has a repeating unit represented by the following general formulas (C-Ia) to (C-Id). preferable.

In the general formulas (C-Ia) to (C-Id),
R ₁₀ and R ₁₁ represent a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms.

W ₃ to W ₆ each represents an organic group having at least one of a fluorine atom and a silicon atom.

When W ₁ to W ₆ are organic groups having a fluorine atom, they are fluorinated linear, branched alkyl or cycloalkyl groups having 1 to 20 carbon atoms, or fluorinated having 1 to 20 carbon atoms. It is preferably a linear, branched, or cyclic alkyl ether group.

Examples of the fluorinated alkyl group of W ₁ to W ₆ include trifluoroethyl group, pentafluoropropyl group, hexafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, heptafluorobutyl group, heptafluoroisopropyl group, octafluoro Examples thereof include an isobutyl group, a nonafluorohexyl group, a nonafluoro-t-butyl group, a perfluoroisopentyl group, a perfluorooctyl group, and a perfluoro (trimethyl) hexyl group.

When W ₁ to W ₆ are an organic group having a silicon atom, it is preferably an alkylsilyl structure or a cyclic siloxane structure. Specific examples include groups represented by the above general formulas (CS-1) to (CS-3).

Specific examples of the repeating unit represented by formula (CI) are shown below. X represents a hydrogen atom, —CH ₃ , —F, or —CF ₃ .

Resin (X) may have a repeating unit represented by the following general formula (Ia) in order to adjust the solubility in an organic solvent developer.

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.

R ₁ represents an alkyl group.

R ₂ represents a hydrogen atom or an alkyl group.

In general formula (Ia), the alkyl group in which at least one hydrogen atom of Rf is substituted with a fluorine atom preferably has 1 to 3 carbon atoms, and more preferably a trifluoromethyl group.

The alkyl group for R ₁ is preferably a linear or branched alkyl group having 3 to 10 carbon atoms, and more preferably a branched alkyl group having 3 to 10 carbon atoms.

R ₂ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and more preferably a linear or branched alkyl group having 3 to 10 carbon atoms.

Hereinafter, although the specific example of the repeating unit represented by general formula (Ia) is given, this invention is not limited to this.

Resin (X) may further have a repeating unit represented by the following general formula (III).

In general formula (III):
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.

L ₆ represents a single bond or a divalent linking group.

In the general formula (III), the alkyl group of R ₄ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.

The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.

The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.

The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.

The trialkylsilyl group is preferably a trialkylsilyl group having 3 to 20 carbon atoms.

The group having a cyclic siloxane structure is preferably a group having a cyclic siloxane structure having 3 to 20 carbon atoms.

The divalent linking group of L ₆ is preferably an alkylene group (preferably having 1 to 5 carbon atoms) or an oxy group.

Resin (X) may have a lactone group, an ester group, an acid anhydride, or a group similar to the acid-decomposable group in the acid-decomposable resin described later. Resin (X) may further have a repeating unit represented by the following general formula (VIII).

Resin (X) preferably contains a repeating unit (d) derived from a monomer having an alkali-soluble group. Thereby, the solubility with respect to immersion water and the solubility with respect to a coating solvent are controllable. Alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) Imido group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group A group having

The monomer having an alkali-soluble group is preferably a monomer having an acid dissociation index pKa of 4 or more, more preferably a monomer having a pKa of 4 to 13, and most preferably a monomer having a pKa of 8 to 13. When pKa contains a monomer of 4 or more, swelling during negative-type and positive-type development is suppressed, and not only good developability for an organic solvent developer but also a weakly basic alkaline developer is used. Also good developability can be obtained.

The acid dissociation constant pKa is described in Chemical Handbook (II) (4th revised edition, 1993, edited by The Chemical Society of Japan, Maruzen Co., Ltd.), and the pKa value of a monomer containing an alkali-soluble group is, for example, infinite It can measure at 25 degreeC using a dilution solvent.

The monomer having a pKa of 4 or more is not particularly limited, and examples thereof include monomers having an acid group (alkali-soluble group) such as a phenolic hydroxyl group, a sulfonamide group, —COCH ₂ CO—, a fluoroalcohol group, and a carboxylic acid group. Can be mentioned. In particular, a monomer containing a fluoroalcohol group is preferred. The fluoroalcohol group is a fluoroalkyl group substituted with at least one hydroxyl group, preferably having 1 to 10 carbon atoms, more preferably having 1 to 5 carbon atoms. Specific examples of the fluoroalcohol group include, for example, —CF ₂ OH, —CH ₂ CF ₂ OH, —CH ₂ CF ₂ CF ₂ OH, —C (CF ₃ ) ₂ OH, —CF ₂ CF (CF ₃ ) OH. , —CH ₂ C (CF ₃ ) ₂ OH, and the like. Particularly preferred as the fluoroalcohol group is a hexafluoroisopropanol group.

The total amount of repeating units derived from the monomer having an alkali-soluble group in the resin (X) is preferably 0 to 90 mol%, more preferably 0 to 80 mol, based on all repeating units constituting the resin (X). The mol% is even more preferably 0 to 70 mol%.

The monomer having an alkali-soluble group may contain only one acid group or two or more acid groups. The repeating unit derived from this monomer preferably has two or more acid groups per repeating unit, more preferably 2 to 5 acid groups, and 2 to 3 acid groups. It is particularly preferred.

Preferred specific examples of the repeating unit derived from the monomer having an alkali-soluble group are shown below, but are not limited thereto.

The resin (X) is preferably any resin selected from the following (X-1) to (X-8).

(X-1) A resin having a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), more preferably a resin having only a repeating unit (a).

(X-2) A resin having a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, more preferably a resin having only a repeating unit (b).

(X-3) a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), a branched alkyl group (preferably having 4 to 20 carbon atoms), a cycloalkyl group (preferably having 4 carbon atoms) To 20), a repeating unit (c) having a branched alkenyl group (preferably having 4 to 20 carbon atoms), a cycloalkenyl group (preferably having 4 to 20 carbon atoms) or an aryl group (preferably having 4 to 20 carbon atoms) More preferably, a copolymer resin of the repeating unit (a) and the repeating unit (c).

(X-4) a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, a branched alkyl group (preferably having 4 to 20 carbon atoms), a cycloalkyl group (preferably having 4 to 20 carbon atoms), Resin having a repeating unit (c) having a branched alkenyl group (preferably having 4 to 20 carbon atoms), a cycloalkenyl group (preferably having 4 to 20 carbon atoms) or an aryl group (preferably having 4 to 20 carbon atoms) More preferably, a copolymer resin of the repeating unit (b) and the repeating unit (c).

(X-5) a resin having a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms) and a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, more preferably a repeating unit Copolymer resin of unit (a) and repeating unit (b).

(X-6) a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, and a branched alkyl group (preferably Is a C4-20), cycloalkyl group (preferably C4-20), branched alkenyl group (preferably C4-20), cycloalkenyl group (preferably C4-20) or aryl A resin having a repeating unit (c) having a group (preferably having 4 to 20 carbon atoms), more preferably a copolymer resin of the repeating unit (a), the repeating unit (b) and the repeating unit (c).

Repeating unit (c) having a branched alkyl group, cycloalkyl group, branched alkenyl group, cycloalkenyl group or aryl group in resins (X-3), (X-4) and (X-6) In consideration of hydrophilicity / hydrophobicity, interaction, etc., an appropriate functional group can be introduced.

(X-7) The repeating unit constituting each of the above (X-1) to (X-6) further has a repeating unit having an alkali-soluble group (d) (preferably having an alkali-soluble group having a pKa of 4 or more. Resin having a repeating unit).

(X-8) A resin having only a repeating unit having an alkali-soluble group (d) having a fluoroalcohol group.

Resins (X-3), (X-4), (X-6), and (X-7) have a repeating unit (a) having a fluoroalkyl group and / or a trialkylsilyl group, or a cyclic siloxane structure The repeating unit (b) is preferably 10 to 99 mol%, more preferably 20 to 80 mol%.

In addition, by having an alkali-soluble group (d) in the resin (X-7), not only the ease of stripping when using an organic solvent developer, but also other stripping solutions such as alkaline aqueous solutions are used as stripping solutions. The ease of peeling when used is improved.

Resin (X) is preferably solid at room temperature (25 ° C.). Further, the glass transition temperature (Tg) is preferably 50 to 200 ° C., more preferably 80 to 160 ° C.

“Solid at 25 ° C.” means that the melting point is 25 ° C. or higher.

The glass transition temperature (Tg) can be measured by scanning calorimetry (for example, differential scanning calorimeter). For example, the specific volume changed when the sample was heated once, cooled and then heated again at 5 ° C./min. It can be measured by analyzing the value.

Resin (X) is preferably insoluble in an immersion liquid (preferably water) and soluble in an organic solvent developer (preferably a developer containing an ester solvent). In the case where the pattern forming method of the present invention further includes a step of developing using an alkaline developer, the resin (X) can be used with respect to the alkaline developer from the viewpoint of being able to develop and peel off using the alkaline developer. It is preferably soluble.

When the resin (X) has a silicon atom, the content of the silicon atom is preferably 2 to 50% by mass and more preferably 2 to 30% by mass with respect to the molecular weight of the resin (X). The repeating unit containing a silicon atom is preferably 10 to 100% by mass in the resin (X), and more preferably 20 to 100% by mass.

By making the content of silicon atoms and the content of repeating units containing silicon atoms within the above range, insolubility to immersion liquid (preferably water), easy peeling of protective film when using organic solvent developer, Furthermore, both incompatibility with actinic ray-sensitive or radiation-sensitive film can be improved.

By making the content of the fluorine atom and the content of the repeating unit containing the fluorine atom within the above range, insolubility to immersion liquid (preferably water), easy peeling of the protective film when using an organic solvent developer, Furthermore, both incompatibility with actinic ray-sensitive or radiation-sensitive film can be improved.

When the resin (X) has a fluorine atom, the fluorine atom content is preferably 5 to 80% by mass and more preferably 10 to 80% by mass with respect to the molecular weight of the resin (X). In addition, the repeating unit containing a fluorine atom is preferably 10 to 100% by mass, more preferably 30 to 100% by mass in the resin (X).

The weight average molecular weight in terms of standard polystyrene of the resin (X) is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, still more preferably 2,000 to 15,000, particularly preferably. Is between 3,000 and 15,000.

Of course, the resin (X) has few impurities such as metals, but from the viewpoint of reducing elution from the protective film to the immersion liquid, the residual monomer amount is preferably 0 to 10% by mass, more preferably. Is more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably 1 to 5, more preferably 1 to 3, and still more preferably 1 to 1.5.

Resin (X) can use various commercial products, and can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned.

The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferable initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. A chain transfer agent can also be used as needed. The concentration of the reaction is usually 5 to 50% by mass, preferably 20 to 50% by mass, more preferably 30 to 50% by mass. The reaction temperature is usually 10 ° C. to 150 ° C., preferably 30 ° C. to 120 ° C., more preferably 60 to 100 ° C.

After the reaction is complete, cool to room temperature and purify. Purification can be accomplished by a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water and an appropriate solvent, and a purification method in a solution state such as ultrafiltration that extracts and removes only those having a specific molecular weight or less. , Reprecipitation method that removes residual monomer by coagulating resin in poor solvent by dripping resin solution into poor solvent and purification in solid state such as washing filtered resin slurry with poor solvent A normal method such as a method can be applied. For example, the resin is precipitated as a solid by contacting a solvent (poor solvent) in which the resin is hardly soluble or insoluble in a volume amount of 10 times or less, preferably 10 to 5 times the volume of the reaction solution.

The solvent (precipitation or reprecipitation solvent) used in the precipitation or reprecipitation operation from the polymer solution may be a poor solvent for this polymer. For example, hydrocarbons (pentane, hexane, Aliphatic hydrocarbons such as heptane and octane; Cycloaliphatic hydrocarbons such as cyclohexane and methylcyclohexane; Aromatic hydrocarbons such as benzene, toluene and xylene), halogenated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride, etc.) Halogenated aliphatic hydrocarbons; halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene), nitro compounds (nitromethane, nitroethane, etc.), nitriles (acetonitrile, benzonitrile, etc.), ethers (diethyl ether, diisopropyl ether, dimethoxyethane) Chain Ether; cyclic ethers such as tetrahydrofuran and dioxane), ketones (acetone, methyl ethyl ketone, diisobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, etc.), carbonates (dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, etc.), alcohols ( (Methanol, ethanol, propanol, isopropyl alcohol, butanol, etc.), carboxylic acid (acetic acid, etc.), water, a mixed solvent containing these solvents, and the like. Among these, as a precipitation or reprecipitation solvent, a solvent containing at least an alcohol (particularly methanol or the like) or water is preferable. In such a solvent containing at least hydrocarbon, the ratio of alcohol (particularly methanol) and other solvent (for example, ester such as ethyl acetate, ethers such as tetrahydrofuran) is, for example, the former / the latter (volume ratio). 25 ° C.) = 10/90 to 99/1, preferably the former / the latter (volume ratio; 25 ° C.) = 30/70 to 98/2, more preferably the former / the latter (volume ratio; 25 ° C.) = 50 / It is about 50 to 97/3.

The amount of the precipitation or reprecipitation solvent used can be appropriately selected in consideration of efficiency, yield, and the like, but generally, 100 to 10,000 parts by mass, preferably 200 to 2000 parts by mass with respect to 100 parts by mass of the polymer solution, More preferably, it is 300 to 1000 parts by mass.

The diameter of the nozzle when the polymer solution is supplied into the precipitation or reprecipitation solvent (poor solvent) is preferably 4 mmφ or less (for example, 0.2 to 4 mmφ). The supply speed (dropping speed) of the polymer solution into the poor solvent is, for example, about 0.1 to 10 m / second, preferably about 0.3 to 5 m / second as the linear speed.

Precipitation or reprecipitation operation is preferably performed with stirring. As a stirring blade used for stirring, for example, a desk turbine, a fan turbine (including a paddle), a curved blade turbine, an arrow blade turbine, a fiddler type, a bull margin type, an angled blade fan turbine, a propeller, a multistage type, an anchor type (or Horseshoe type), gate type, double ribbon, screw, etc. can be used. Stirring is preferably further performed for 10 minutes or more, particularly 20 minutes or more after the supply of the polymer solution. When the stirring time is short, the monomer content in the polymer particles may not be sufficiently reduced. Further, the polymer solution and the poor solvent can be mixed and stirred using a line mixer instead of the stirring blade.

The temperature at the time of precipitation or reprecipitation can be appropriately selected in consideration of efficiency and operability, but is usually about 0 to 50 ° C., preferably around room temperature (for example, about 20 to 35 ° C.). The precipitation or reprecipitation operation can be performed by a known method such as a batch method or a continuous method using a conventional mixing vessel such as a stirring tank.

Precipitated or re-precipitated particulate polymer is usually subjected to conventional solid-liquid separation such as filtration and centrifugation, and dried before use. Filtration is performed using a solvent-resistant filter medium, preferably under pressure. Drying is performed at a temperature of about 30 to 100 ° C., preferably about 30 to 50 ° C. under normal pressure or reduced pressure (preferably under reduced pressure).

In addition, once the resin is precipitated and separated, it may be dissolved again in a solvent, and the resin may be brought into contact with a hardly soluble or insoluble solvent.

That is, after completion of the radical polymerization reaction, a solvent in which the polymer is hardly soluble or insoluble is contacted to precipitate the resin (step a), the resin is separated from the solution (step b), and the resin solution A is dissolved again in the solvent. Preparation (step c), and then contacting the resin solution A with a solvent in which the resin is hardly soluble or insoluble in a volume amount that is less than 10 times that of the resin solution A (preferably a volume amount that is 5 times or less). It may be a method including depositing a resin solid (step d) and separating the deposited resin (step e).

The solvent used in the preparation of the resin solution A can be the same solvent as the solvent that dissolves the monomer in the polymerization reaction, and may be the same as or different from the solvent used in the polymerization reaction.

[solvent]
The protective film forming composition used in the pattern forming method of the present invention is used by dissolving a resin in a solvent in order to uniformly form the protective film forming composition on the actinic ray-sensitive or radiation-sensitive film. It is preferable.

In order to form a good pattern without dissolving the actinic ray-sensitive or radiation-sensitive film, the protective film-forming composition of the present invention contains a solvent that does not dissolve the actinic ray-sensitive or radiation-sensitive film. It is preferable to use a solvent having a component different from that of the negative developer. Further, from the viewpoint of preventing elution into the immersion liquid, it is preferable that the solubility in the immersion liquid is low, and it is more preferable that the solubility in water is low. In the present specification, “low solubility in immersion liquid” indicates that the immersion liquid is insoluble. Similarly, “low solubility in water” indicates water insolubility. From the viewpoint of volatility and coatability, the boiling point of the solvent is preferably 90 ° C to 200 ° C.

The low solubility in the immersion liquid means that, for example, the solubility in water, the composition for forming a protective film is applied on a silicon wafer and dried to form a film. It means that the decrease rate of the film thickness after dipping for 10 minutes at ° C. and drying is within 3% of the initial film thickness (typically 50 nm).

In the present invention, from the viewpoint of uniformly applying the protective film, the solid content concentration is 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, and most preferably 1 to 10% by mass. Use solvent.

The solvent that can be used is not particularly limited as long as it dissolves the resin (X) described below and does not dissolve the actinic ray-sensitive or radiation-sensitive film. However, alcohol solvents, fluorine solvents, and hydrocarbon solvents may be used. It is preferable to use a non-fluorinated alcohol solvent. This further improves the insolubility in the actinic ray-sensitive or radiation-sensitive film, and when the protective film-forming composition is applied on the actinic-ray-sensitive or radiation-sensitive film, A protective film can be formed more uniformly without dissolving the radiation film.

The alcohol solvent is preferably a monohydric alcohol from the viewpoint of applicability, and more preferably a monohydric alcohol having 4 to 8 carbon atoms. As the monohydric alcohol having 4 to 8 carbon atoms, a linear, branched or cyclic alcohol can be used, but a linear or branched alcohol is preferred. Examples of such alcohol solvents include 1-butanol, 2-butanol, 3-methyl-1-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 1 -Heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, 4-methyl-1-pentanol, 4-methyl-2- Pentanol and the like can be used. Among them, 1-butanol, 1-hexanol, 1-pentanol, 3-methyl-1-butanol, and 4-methyl-2-pentanol are preferable.

Examples of the fluorine-based solvent include 2,2,3,3,4,4-hexafluoro-1-butanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol. 2,2,3,3,4,4,5,5,6,6-decafluoro-1-hexanol, 2,2,3,3,4,4-hexafluoro-1,5-pentanediol, 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol, 2,2,3,3,4,4,5,5,6,6,7,7- Dodecafluoro-1,8-octanediol, 2-fluoroanisole, 2,3-difluoroanisole, perfluorohexane, perfluoroheptane, perfluoro-2-pentanone, perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran, perf Oro tributylamine, include perfluoro tetrapentyl amine or the like, and among this, can be preferably used a fluorinated alcohol or fluorinated hydrocarbon solvent.

Examples of ketone solvents include 4-methyl-2-pentanone, 2,4-dimethyl-2-pentanone, 3-penten-2-one, 2-nonanone, 3-heptanone, and 3-methylcyclopentanone. Can be used.

Examples of hydrocarbon solvents include aromatic hydrocarbon solvents such as toluene, xylene, and anisole, n-heptane, n-nonane, n-octane, n-decane, 2-methylheptane, 3-methylheptane, 3, 3 -Aliphatic hydrocarbon solvents such as dimethylhexane and 2,3,4-trimethylpentane, etc. These solvents may be used singly or in combination.

When a solvent other than the above is mixed, the mixing ratio is usually 0 to 30% by mass, preferably 0 to 20% by mass, more preferably 0 to 10% by mass with respect to the total amount of the solvent for the protective film forming composition. %. By mixing a solvent other than the above, solubility in an actinic ray-sensitive or radiation-sensitive film, solubility of the resin in the protective film-forming composition, elution characteristics from the actinic ray-sensitive or radiation-sensitive film, Etc. can be adjusted appropriately.

[Surfactant]
It is preferable that the composition for forming a protective film of the present invention further contains a surfactant. The surfactant is not particularly limited, and can be an anionic surfactant or a cationic surfactant as long as the protective film-forming composition can be uniformly formed and can be dissolved in the solvent of the protective film-forming composition. Either a surfactant or a nonionic surfactant can be used.

The addition amount of the surfactant is preferably 0.001 to 20% by mass, more preferably 0.01 to 10% by mass.

Surfactant may be used alone or in combination of two or more.

Examples of the surfactant include an alkyl cation surfactant, an amide type quaternary cationic surfactant, an ester type quaternary cationic surfactant, an amine oxide surfactant, a betaine surfactant, and an alkoxy. Rate surfactants, fatty acid ester surfactants, amide surfactants, alcohol surfactants, ethylenediamine surfactants, fluorine and / or silicon surfactants (fluorine surfactants, silicon Those selected from system surfactants and surfactants having both fluorine atoms and silicon atoms can be preferably used.

Specific examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene Polyoxyethylene alkyl allyl ethers such as nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Sorbitan fatty acid esters such as rate, polyoxyethylene sorbitan monolaurate, polyoxyethylene Surfactants such as rubitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, and commercially available surfactants listed below may be used as they are. it can.

Examples of commercially available surfactants that can be used include EFTOP EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 and 4430 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176 and F189. F113, F110, F177, F120, R08 (manufactured by Dainippon Ink & Chemicals, Inc.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (Manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (manufactured by Toagosei Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), F-top EF121, EF122A, EF122B, RF122C, EF125M , EF135M, EF351, 352, EF801, EF802, E 601 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 (manufactured by OMNOVA), FTX-204D, 208G, 218G, 230G, 204D, 208D, 212D, 218, 222D (manufactured by Neos) Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

<Method for adjusting composition for forming protective film>
The composition for forming a protective film of the present invention is preferably subjected to filter filtration by dissolving the above-described components in a solvent. The filter is preferably made of polytetrafluoroethylene, polyethylene or nylon having a pore size of preferably 0.1 μm or less, more preferably 0.05 μm or less, and still more preferably 0.03 μm or less. Note that a plurality of types of filters may be connected in series or in parallel. Moreover, the protective film-forming composition may be filtered a plurality of times, and the step of filtering a plurality of times may be a circulation filtration step. Furthermore, you may perform a deaeration process etc. with respect to the composition for protective film formation before and after filter filtration. The composition for forming a protective film preferably does not contain impurities such as metals. As a content rate of the metal component contained in these materials, 10 ppm or less is preferable, 5 ppm or less is more preferable, 1 ppm or less is still more preferable, and it is especially preferable that it is substantially not included (below the detection limit of a measuring device). .

<Pattern formation method>
As described above, the pattern forming method of the present invention includes:
Applying an actinic ray-sensitive or radiation-sensitive resin composition on a substrate to form an actinic ray-sensitive or radiation-sensitive film;
Applying a protective film-forming composition on the actinic ray-sensitive or radiation-sensitive film to form a protective film (topcoat);
Exposing the actinic ray-sensitive or radiation-sensitive film coated with the protective film;
Developing the exposed actinic ray-sensitive or radiation-sensitive film with a developer containing an organic solvent.

In one form, the pattern formation method of the present invention may include a heating step, and may include a heating step a plurality of times.
Moreover, the pattern formation method of this invention may include the exposure process in multiple times in one form.

Moreover, in one form, the pattern formation method of this invention may include the image development process in multiple times, for example, may further include the image development process using the developing solution containing alkaline aqueous solution.

Moreover, the pattern formation method of this invention may include the rinse process in one form.
In one embodiment, the pattern forming method of the present invention may release the protective film at the same time as the organic solvent development by dissolving the protective film in the organic solvent developer in the organic solvent developing step. In addition to the solvent development step, a step of removing the protective film using a predetermined release agent may be included.

Hereinafter, each process included in the pattern forming method of the present invention will be described in detail.
<Step of forming an actinic ray-sensitive or radiation-sensitive film>
Application of the actinic ray-sensitive or radiation-sensitive resin composition onto the substrate may be any method as long as the actinic ray-sensitive or radiation-sensitive resin composition can be applied onto the substrate, and is conventionally known. The spin coating method, spray method, roller coating method, dipping method and the like can be used, and the resist composition is preferably applied by the spin coating method.

In the present invention, the substrate on which the film is formed is not particularly limited, and an inorganic substrate such as silicon, SiN, SiO ₂ or TiN, a coated inorganic substrate such as SOG, a semiconductor manufacturing process such as an IC, a liquid crystal, or a thermal head A substrate generally used in a circuit board manufacturing process such as a lithography process of other fabrication can be used.

Before forming the actinic ray-sensitive or radiation-sensitive film, an antireflection film may be coated on the substrate in advance.

As the antireflection film, any of an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and amorphous silicon, and an organic film type made of a light absorber and a polymer material can be used. In addition, as an organic anti-reflective coating, ARC series such as DUV30 series manufactured by Brewer Science, DUV-40 series, AR-2, AR-3, AR-5 manufactured by Shipley, ARC29A manufactured by Nissan Chemical Co., etc. Commercially available organic antireflection films can also be used.
The actinic ray-sensitive or radiation-sensitive resin composition that can be used will be described in detail later.

<Process for forming protective film>
The pattern forming method of the present invention comprises an actinic ray-sensitive or radiation-sensitive film after the step of forming the actinic ray-sensitive or radiation-sensitive film and before the step of exposing the actinic ray-sensitive or radiation-sensitive film with an organic solvent developer. A step of forming the protective film (topcoat) by applying the protective film-forming composition described above on the light-sensitive or radiation-sensitive film. The functions necessary for the top coat are suitability for application on the actinic ray-sensitive or radiation-sensitive film, transparency to radiation, particularly 193 nm, and poor solubility in immersion liquid (preferably water). It is preferable that the actinic ray-sensitive or radiation-sensitive resin composition is not mixed with the actinic ray-sensitive or radiation-sensitive film, and can be uniformly applied to the actinic ray-sensitive or radiation-sensitive film surface.

The method for applying the protective film-forming composition is not particularly limited, and for example, a spin coating method can be applied.

The thickness of the protective film is not particularly limited, but is usually 1 nm to 300 nm, preferably 10 nm to 300 nm, more preferably 20 nm to 200 nm, still more preferably 30 nm to 100 nm from the viewpoint of transparency to the exposure light source. .

After forming the protective film, the substrate is heated as necessary.

The refractive index of the protective film is preferably close to the refractive index of the actinic ray-sensitive or radiation-sensitive film from the viewpoint of resolution.

The protective film is preferably insoluble in the immersion liquid, and more preferably insoluble in water.

With respect to the receding contact angle of the protective film, the receding contact angle (23 ° C.) of the immersion liquid with respect to the protective film is preferably 50 ° to 100 °, and preferably 60 ° to 80 °, from the viewpoint of immersion liquid followability. It is more preferable. Even more preferably, the receding contact angle of water with respect to the protective film (23 ° C.) is 50 to 100 degrees, and most preferably the receding contact angle of water with respect to the protective film (23 ° C.) is 60 to 80 degrees. .

When the exposure process in the pattern forming method of the present invention is an immersion exposure process, the immersion liquid needs to move on the wafer following the movement of the exposure head scanning the wafer at high speed to form the exposure pattern. Therefore, the contact angle of the immersion liquid with respect to the actinic ray-sensitive or radiation-sensitive film in a dynamic state is important, and in order to obtain better resist performance, it has a receding contact angle in the above specific range. It is preferable.

<Step of removing the protective film>
As described above, when removing the protective film, an organic solvent developer may be used, or a separate release agent may be used. When peeling is performed separately from the development step, the timing of peeling is preferably after exposure, and when the PEB step described later is included, after PEB is more preferable. As the release agent, a solvent having a small penetration into the actinic ray-sensitive or radiation-sensitive film is preferable. It is preferable that the peeling step can be carried out with an organic solvent developer in that the peeling step can be performed simultaneously with the actinic ray sensitive or radiation sensitive film developing step. The organic solvent developer used for peeling is not particularly limited as long as it can dissolve and remove the low-exposed portion of the actinic ray-sensitive or radiation-sensitive film, and is a ketone solvent, an ester solvent, an alcohol solvent, A developer containing a polar solvent such as an amide solvent or an ether solvent and a hydrocarbon solvent can be selected, and a developer containing a ketone solvent, an ester solvent, an alcohol solvent, or an ether solvent is used. It is preferable to use a developer containing an ester solvent, and it is most preferable to use a developer containing butyl acetate. From the viewpoint of peeling with an organic solvent developer, the protective film has a dissolution rate in the organic solvent developer of preferably 1 nm / sec to 300 nm / sec, more preferably 10 nm / sec to 100 nm / sec.

Here, the dissolution rate of the protective film in the organic solvent developer is a film thickness decreasing rate when the protective film is formed and then exposed to the developer. In the present invention, the film was immersed in a butyl acetate solution at 23 ° C. Speed.

By setting the dissolution rate of the protective film in the organic solvent developer to 1 / sec or more, preferably 10 nm / sec or more, there is an effect of reducing development defects after development. Further, by setting it to 300 nm / sec or less, preferably 100 nm / sec, there is an effect that the line edge roughness of the pattern after development is likely to be improved due to the effect of reducing the exposure unevenness at the time of exposure.

The protective film may be removed using other known developing solutions such as an alkaline aqueous solution. Specific examples of the aqueous alkali solution that can be used include an aqueous solution of tetramethylammonium hydroxide.

<Exposure process>
The exposure to the actinic ray-sensitive or radiation-sensitive film can be performed by a generally well-known method. Preferably, the actinic ray-sensitive or radiation-sensitive film is irradiated with actinic rays or radiation through a predetermined mask. The exposure amount can be appropriately set, but is usually 1 to 100 mJ / cm ² .

The wavelength of the light source used in the exposure apparatus of the present invention is not particularly limited, but it is preferable to use light having a wavelength of 250 nm or less. Examples thereof include KrF excimer laser light (248 nm), ArF excimer laser light (193 nm). ), F ₂ excimer laser light (157 nm), EUV light (13.5 nm), electron beam, and the like. Among these, it is more preferable to use ArF excimer laser light (193 nm).

When performing the exposure process, (1) after forming the film on the substrate, before the exposure process, and / or (2) after the exposure process, before the process of heating the film, A step of washing with an aqueous chemical may be performed.

When performing immersion exposure, the immersion liquid should be a liquid that is transparent to the exposure wavelength and that has the smallest possible temperature coefficient of refractive index so as to minimize distortion of the optical image projected onto the film. In particular, when the exposure light source is ArF excimer laser light (wavelength: 193 nm), it is preferable to use water from the viewpoints of availability and ease of handling in addition to the above-described viewpoints.

When water is used, an additive (liquid) that decreases the surface tension of water and increases the surface activity may be added in a small proportion. This additive is preferably one that does not dissolve the actinic ray-sensitive or radiation-sensitive film on the wafer and can ignore the influence on the optical coating on the lower surface of the lens element. As water to be used, distilled water is preferable. Further, pure water filtered through an ion exchange filter or the like may be used. Thereby, distortion of the optical image projected on the resist due to mixing of impurities can be suppressed.

Also, a medium having a refractive index of 1.5 or more can be used in that the refractive index can be further improved. This medium may be an aqueous solution or an organic solvent.

The pattern forming method of the present invention may have an exposure step a plurality of times. In this case, the same light source or different light sources may be used for the multiple exposures, but ArF excimer laser light (wavelength: 193 nm) is preferably used for the first exposure.

<Organic solvent development process>
The pattern formation method of the present invention includes a step of developing using an organic solvent developer.
As an organic solvent that can be used for organic solvent development, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents can be used. For example, 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutylketone, cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone Ketone solvents such as acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, isoamyl acetate, propylene glycol Monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene group Cole monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, lactic acid Ester solvents such as propyl, methyl 2-hydroxyisobutyrate and butyl butanoate can be used.

Examples of alcohol solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n- Alcohols such as octyl alcohol and n-decanol, glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol, propylene glycol, diethylene glycol monomethyl ether and triethylene glycol mono Examples include glycol ether solvents such as ethyl ether and methoxymethylbutanol. That.

Examples of the ether solvent include dioxane, tetrahydrofuran and the like in addition to the glycol ether solvent.

As the amide solvent, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone, etc. can be used. .

Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as pentane, hexane, octane and decane.

A plurality of the above solvents may be mixed, or may be used by mixing with a solvent other than the above or water.

As a development method, a method of developing by raising the developer on the surface of the substrate by surface tension and allowing it to stand for a certain time (paddle method), a method of spraying the developer on the surface of the substrate (spray method), and rotating at a constant speed There is a method such as a method of continuously applying the developer while scanning the developer application nozzle on the substrate at a constant speed (dynamic dispensing method).

The vapor pressure of the negative developer is preferably 5 kPa or less, more preferably 3 kPa or less, and most preferably 2 kPa or less at 20 ° C. By setting the vapor pressure of the negative developer to 5 kPa or less, evaporation of the developer on the substrate or in the developing cup is suppressed, and the temperature uniformity in the wafer surface is improved. As a result, the dimensions in the wafer surface are uniform. Sexuality improves.

Specific examples having a vapor pressure of 5 kPa or less at 20 ° C. include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenyl Ketone solvents such as acetone and methyl isobutyl ketone, butyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propylene lactate Ester solvent such as n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decanol Alcohol solvents such as ethylene glycol, diethylene glycol, triethylene glycol, and other glycol solvents, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol, propylene glycol, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethyl Glycol ether solvents such as butanol, ether solvents such as tetrahydrofuran, N-methyl-2 Pyrrolidone, N, N- dimethylacetamide, N, N-dimethylformamide amide solvents, toluene, aromatic hydrocarbon solvents such as xylene, octane, aliphatic hydrocarbon solvents decane.

Specific examples having a vapor pressure of 2 kPa or less at 20 ° C., which is the most preferable range, include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutyl ketone, and cyclohexanone. , Ketone solvents such as methylcyclohexanone and phenylacetone, butyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate Ester solvents such as 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl lactate, butyl lactate, propyl lactate, Alcohol solvents such as alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decanol, ethylene glycol, diethylene glycol, triethylene glycol, etc. Glycol solvents, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol, propylene glycol, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, glycol ether solvents such as methoxymethylbutanol, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, amide solvents of N, N-dimethylformamide, aromatic hydrocarbons such as xylene Agents, octane, aliphatic hydrocarbon solvents decane Ageraru.

An appropriate amount of a surfactant can be added to the developer that can be used for negative development, if necessary.

The surfactant is not particularly limited, and for example, an ionic or nonionic fluorine-based and / or silicon-based surfactant can be used. Examples of these fluorine and / or silicon surfactants include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, US Pat. No. 5,405,720, The surfactants described in the specifications of US Pat. Preferably, it is a nonionic surfactant. Although it does not specifically limit as a nonionic surfactant, It is still more preferable to use a fluorochemical surfactant or a silicon-type surfactant.

The amount of the surfactant used is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass with respect to the total amount of the developer.

The organic solvent developer may contain a basic compound. Specific examples and preferred examples of the basic compound that can be contained in the organic solvent developer used in the present invention are the same as those described later as basic compounds that can be contained in the actinic ray-sensitive or radiation-sensitive resin composition.

As a developing method, for example, a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and is left stationary for a certain time (paddle) Method), a method of spraying the developer on the substrate surface (spray method), a method of continuously applying the developer while scanning the developer application nozzle at a constant speed on a substrate rotating at a constant speed (dynamic dispensing method) ) Etc. can be applied.

<Rinse process>
Moreover, you may implement the rinse process which stops image development, after the process of developing organic solvent, substituting with another solvent.

The rinsing solution used in the rinsing step after organic solvent development is not particularly limited as long as the resist pattern is not dissolved, and a solution containing a general organic solvent can be used. As the rinsing liquid, it is preferable to use a rinsing liquid containing at least one organic solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents. . More preferably, after the negative development, a cleaning step is performed using a rinse solution containing at least one organic solvent selected from a ketone solvent, an ester solvent, an alcohol solvent, and an amide solvent. More preferably, after the negative development, a step of washing with a rinse solution containing an alcohol solvent or an ester solvent is performed. Particularly preferably, after negative development, a step of washing with a rinsing solution containing a monohydric alcohol is performed. Here, examples of the monohydric alcohol used in the rinsing step after the negative development include linear, branched, and cyclic monohydric alcohols. Specific examples include 1-butanol, 2-butanol, 3- Methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3 -Heptanol, 3-octanol, 4-octanol and the like can be used, and 1-hexanol, 2-hexanol, 1-pentanol, and 3-methyl-1-butanol are preferable.

A plurality of the above components may be mixed, or may be used by mixing with an organic solvent other than the above.

The water content in the rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. By setting the water content to 10% by mass or less, good development characteristics can be obtained.

The vapor pressure of the rinsing liquid used after organic solvent development is preferably 0.05 kPa or more and 5 kPa or less at 20 ° C., more preferably 0.1 kPa or more and 5 kPa or less, and most preferably 0.12 kPa or more and 3 kPa or less. By setting the vapor pressure of the rinse liquid to 0.05 kPa or more and 5 kPa or less, the temperature uniformity in the wafer surface is improved, and further, the swelling due to the penetration of the rinse solution is suppressed, and the dimensional uniformity in the wafer surface. Improves.
An appropriate amount of a surfactant can be added to the rinse solution.

In the rinsing step, the wafer subjected to the organic solvent development is cleaned using the rinsing liquid containing the organic solvent. The method of the cleaning treatment is not particularly limited. For example, a method of continuously applying the rinse liquid onto the substrate rotating at a constant speed (rotary coating method), or immersing the substrate in a tank filled with the rinse liquid for a certain period of time. A method (dip method), a method of spraying a rinsing liquid onto the substrate surface (spray method), etc. can be applied. Among these, a cleaning process is performed by a spin coating method, and after cleaning, the substrate is rotated at a speed of 2000 rpm to 4000 rpm. It is preferable to rotate and remove the rinse liquid from the substrate.

<Alkali development process>
The pattern forming method of the present invention may further include a step of developing using an alkaline developer.

Examples of the alkali developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, di- Secondary amines such as n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium such as tetramethylammonium hydroxide and tetraethylammonium hydroxide Alkaline aqueous solutions such as salts, cyclic amines such as pyrrole and pihelidine can be used. Among these, it is preferable to use an aqueous solution of tetraethylammonium hydroxide.

Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkali developer.

The alkali concentration of the alkali developer is usually from 0.01 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.
The development time using an alkali developer is usually 10 to 300 seconds.
The alkali concentration (and pH) and development time of the alkali developer can be appropriately adjusted according to the pattern to be formed.

As the rinsing solution for the rinsing step performed after the alkali development step, pure water can be used and an appropriate amount of a surfactant can be added.

Further, after the developing process or the rinsing process, a process of removing the developing solution or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.

Furthermore, after the rinsing process or the process with the supercritical fluid, a heat treatment can be performed in order to remove moisture remaining in the pattern.

[Heating process]
The pattern forming method of the present invention may further include a heating step, and may include a heating step a plurality of times.
In one embodiment, the pattern forming method of the present invention may be preheated (hereinafter referred to as “PB” (Prebake; PB) or “after formation of an actinic ray-sensitive or radiation-sensitive film” and / or after formation of a protective film. It is preferable to include a step called “pre-baking”).

That is, the pattern forming method of the present invention may include a pre-baking step between the step of forming an actinic ray-sensitive or radiation-sensitive film and the step of forming a protective film, or forming a protective film. It may be included between the process to perform and the exposure process, and the prebaking process may be included in both. By pre-baking, insoluble residual solvent is removed, and a uniform film can be formed. In the following, the pre-baking step performed between the step of forming the actinic ray-sensitive or radiation-sensitive film and the step of forming the protective film is referred to as “PB step before forming the protective film”, and the step of forming the protective film A pre-bake process performed between the exposure process and the exposure process is referred to as a “PB process after forming the protective film”.

The heating temperature in the PB step before forming the protective film is preferably, for example, 50 ° C. to 160 ° C., more preferably 60 ° C. to 140 ° C.

The heating temperature in the PB step after forming the protective film is preferably, for example, 80 ° C. to 160 ° C., more preferably 100 ° C. to 150 ° C., further preferably 110 ° C. to 145 ° C., and particularly preferably 120 ° C. to 140 ° C. By increasing the pre-baking temperature after the formation of the protective film, the low-molecular components are likely to gather on the resist film side of the top coat, thereby further improving the DOF improvement effect.

In another form, the pattern forming method of the present invention preferably includes a post-exposure baking (PEB) step after the exposure step and before the development step. PEB promotes the reaction of the exposed area and improves the sensitivity and pattern profile.

The heating temperature in the PEB process is preferably 40 ° C. to 160 ° C., for example.

The heating time is not particularly limited in both the PB process and the PEB process, and is preferably, for example, 30 to 300 seconds, more preferably 30 to 180 seconds, and further preferably 30 to 90 seconds.
Heating can be performed by means provided in a normal exposure / developing machine, and may be performed using a hot plate or the like.

<Actinic ray-sensitive or radiation-sensitive resin composition>
Next, the actinic ray-sensitive or radiation-sensitive resin composition suitably used in the pattern forming method of the present invention will be described. <Actinic ray-sensitive or radiation-sensitive resin composition>
(A) Resin whose polarity is increased by the action of an acid The resin whose polarity is increased by the action of an acid used in the actinic ray-sensitive or radiation-sensitive resin composition of the present invention is the main chain or side chain of the resin, or Resins having a group (hereinafter also referred to as “acid-decomposable group”) that decomposes by the action of an acid to generate an alkali-soluble group (hereinafter also referred to as “acid-decomposable group”) in both the main chain and the side chain. Resin (A) "or" resin (A) "), which has a monocyclic or polycyclic alicyclic hydrocarbon structure, increases its polarity by the action of acid, and increases its solubility in an alkaline developer. The resin is preferably a resin with reduced solubility in organic solvents (hereinafter also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”). The reason is not clear, but it is likely that the positive polarity developer (preferably an alkali developer) and the negative developer (preferably, the polarities of the resin greatly change before and after irradiation with actinic rays or radiation. This is considered to be due to the improvement in dissolution contrast when developed using an organic solvent. Furthermore, a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure has high hydrophobicity, and the light irradiation intensity of an actinic ray-sensitive or radiation-sensitive film by a negative developer (preferably an organic solvent). It is considered that developability is improved when developing a weak region.

The actinic ray-sensitive or radiation-sensitive resin composition of the present invention containing a resin whose polarity is increased by the action of an acid can be suitably used when irradiating ArF excimer laser light.

Examples of the alkali-soluble group contained in the alicyclic hydrocarbon-based acid-decomposable resin include phenolic hydroxyl group, carboxylic acid group, fluorinated alcohol group, sulfonic acid group, sulfonamide group, sulfonylimide group, (alkylsulfonyl) (alkylcarbonyl) ) Methylene group, (alkylsulfonyl) (alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkyl) And a group having a carbonyl) methylene group or a tris (alkylsulfonyl) methylene group.

Preferred alkali-soluble groups include carboxylic acid groups, fluorinated alcohol groups (preferably hexafluoroisopropanol), and sulfonic acid groups.

A preferred group as the acid-decomposable group is a group obtained by substituting the hydrogen atom of these alkali-soluble groups with a group capable of leaving with an acid.

Examples of the group capable of leaving with an acid include -C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ). ) (OR ₃₉ ) and the like.

In the formula, R ₃₆ to R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.

R ₀₁ and R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.

The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

Examples of the alicyclic hydrocarbon-based acid-decomposable resin of the present invention include a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pV) and the following general formula (II- A resin containing at least one selected from the group of repeating units represented by AB) is preferred.

In general formulas (pI) to (pV),
R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z represents an atom necessary for forming a cycloalkyl group together with a carbon atom. Represents a group.

R ₁₂ to R ₁₆ each independently represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms. However, at least one of R ₁₂ to R ₁₄ , or any one of R ₁₅ and R ₁₆ represents a cycloalkyl group.

R ₁₇ to R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group. However, at least one of R ₁₇ to R ₂₁ represents a cycloalkyl group. Either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms.

R ₂₂ to R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group. However, at least one of R ₂₂ to R ₂₅ represents a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In general formula (II-AB),
R ₁₁ ′ and R ₁₂ ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.

Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

The general formula (II-AB) is more preferably the following general formula (II-AB1) or general formula (II-AB2).

In the formulas (II-AB1) and (II-AB2),
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , a group capable of decomposing by the action of an acid, —C (═O) —XA′—R ₁₇ ′ represents an alkyl group or a cycloalkyl group. At least two of R ₁₃ ′ to R ₁₆ ′ may combine to form a ring.

Here, R ₅ represents an alkyl group, a cycloalkyl group, or a group having a lactone structure.

X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.

A ′ represents a single bond or a divalent linking group.

R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or a group having a lactone structure.

R ₆ represents an alkyl group or a cycloalkyl group.

N represents 0 or 1.

In the general formulas (pI) to (pV), the alkyl group in R ₁₂ to R ₂₅ represents a linear or branched alkyl group having 1 to 4 carbon atoms.

The cycloalkyl group in R ₁₁ to R ₂₅ or the cycloalkyl group formed by Z and the carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The number of carbon atoms is preferably 6-30, and particularly preferably 7-25. These cycloalkyl groups may have a substituent.

Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, A cyclodecanyl group and a cyclododecanyl group can be mentioned. More preferable examples include an adamantyl group, norbornyl group, cyclohexyl group, cyclopentyl group, tetracyclododecanyl group, and tricyclodecanyl group.

Further substituents for these alkyl groups and cycloalkyl groups include alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, alkoxycarbonyl groups (carbon numbers). 2 to 6). Examples of the substituent that the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom, and an alkoxy group.

The structures represented by the general formulas (pI) to (pV) in the resin can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.

Specific examples include a structure in which a hydrogen atom of a carboxylic acid group, a sulfonic acid group, a phenol group, or a thiol group is substituted with a structure represented by the general formulas (pI) to (pV). The hydrogen atom of the sulfonic acid group is substituted with a structure represented by general formulas (pI) to (pV).

As the repeating unit having an alkali-soluble group protected with a structure represented by the general formulas (pI) to (pV), a repeating unit represented by the following general formula (pA) is preferable.

Here, R represents a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.

A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents. A single bond is preferable.

Rp ₁ represents any group of the above formulas (pI) to (pV).

The repeating unit represented by the general formula (pA) is particularly preferably a repeating unit of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

Hereinafter, specific examples of the repeating unit represented by the general formula (pA) are shown, but the present invention is not limited thereto.

Examples of the halogen atom in the general formula (II-AB), R ₁₁ ′, and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

Examples of the alkyl group for R ₁₁ ′ and R ₁₂ ′ include linear or branched alkyl groups having 1 to 10 carbon atoms.

The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in a resin, and among them, a bridged type alicyclic group. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.

Examples of the skeleton of the alicyclic hydrocarbon formed include those similar to the alicyclic hydrocarbon groups of R ₁₂ to R _{25 in} the general formulas (pI) to (pV).

The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2).

In the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention, the group decomposed by the action of an acid has a partial structure containing the alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pV). It can be contained in at least one repeating unit among the repeating units having, the repeating unit represented by formula (II-AB), and the repeating unit of the copolymerization component described later. The group capable of decomposing by the action of an acid is preferably contained in a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formula (pI) to general formula (pV).

The various substituents R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or the general formula (II-AB2) are atomic groups for forming the alicyclic structure in the general formula (II-AB). It can also be a substituent of the atomic group Z for forming a bridged alicyclic structure.

Specific examples of the repeating unit represented by the general formula (II-AB1) or (II-AB2) include the following specific examples, but the present invention is not limited to these specific examples.

The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a lactone group. As the lactone group, any group can be used as long as it contains a lactone structure, but a group containing a 5- to 7-membered ring lactone structure is preferred, and a bicyclo structure is added to the 5- to 7-membered ring lactone structure, Those in which other ring structures are condensed to form a spiro structure are preferred. It is more preferable to have a repeating unit having a group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are groups represented by general formulas (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), By using a specific lactone structure, line edge roughness and development defects are improved.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. n2 represents an integer of 0 to 4. When n2 is 2 or more, a plurality of Rb ₂ may be the same or different, and a plurality of Rb ₂ may be bonded to form a ring.

Examples of the repeating unit having a group having a lactone structure represented by any one of the general formulas (LC1-1) to (LC1-16) include R _{13 in the} general formula (II-AB1) or (II-AB2). Wherein at least one of 'to R ₁₆ ' has a group represented by the general formulas (LC1-1) to (LC1-16) (for example, R _{5 of} -COOR ₅ is represented by the general formulas (LC1-1) to (LC1) -16), or a repeating unit represented by the following general formula (AI).

In general formula (AI),
R _b0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.

Preferable substituents that the alkyl group for R _b0 may have include a hydroxyl group and a halogen atom.

Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

R _b0 is preferably a hydrogen atom or a methyl group.

A _b represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these. Preferred is a single bond or a linking group represented by —Ab ₁ —CO ₂ —. Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group or a norbornylene group.

V represents a group represented by any one of formulas (LC1-1) to (LC1-16).

The repeating unit having a lactone structure usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.

Specific examples of the repeating unit having a group having a lactone structure are listed below, but the present invention is not limited thereto.

The alicyclic hydrocarbon-based acid-decomposable resin of the present invention has a repeating unit containing an organic group having a polar group, particularly a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. preferable. This improves the substrate adhesion and developer compatibility. The alicyclic hydrocarbon structure of the alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group, a diamantyl group, or a norbornane group. The polar group is preferably a hydroxyl group or a cyano group.

As the alicyclic hydrocarbon structure substituted with a polar group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferable.

In the general formulas (VIIa) to (VIIc),
R _2c to R _4c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R _2c to R _4c represents a hydroxyl group or a cyano group. Preferably, one or two of R _2c to R _4c are a hydroxyl group and the rest are hydrogen atoms.

In general formula (VIIa), it is more preferable that two of R _2c to R _4c are a hydroxyl group and the remaining is a hydrogen atom.

As the repeating unit having a group represented by the general formulas (VIIa) to (VIId), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2) is the above has a group represented by the general formula (VII) (e.g., represents a group R ₅ in -COOR ₅ is a represented by the general formula (VIIa) ~ (VIId)) , or the following general formula (AIIa) ~ ( A repeating unit represented by AId) can be mentioned.

In the general formulas (AIIa) to (AIId),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

R _2c ~ R _4c have the same meanings as R _2c ~ R _4c in formulas (VIIa) ~ (VIIc).

Specific examples of the repeating unit having a structure represented by general formulas (AIIa) to (AIId) are given below, but the present invention is not limited thereto.

The alicyclic hydrocarbon-based acid-decomposable resin of the present invention may have a repeating unit represented by the following general formula (VIII).

In the above general formula (VIII),
Z ₂ represents —O— or —N (R ₄₁ ) —. R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

Examples of the repeating unit represented by the general formula (VIII) include the following specific examples, but the present invention is not limited thereto.

The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a repeating unit having an alkali-soluble group, and more preferably has a repeating unit having a carboxyl group. By containing this, the resolution in contact hole applications increases. The repeating unit having a carboxyl group includes a repeating unit in which a carboxyl group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a carboxyl group in the main chain of the resin through a linking group. Either a repeating unit that is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is introduced at the end of the polymer chain at the time of polymerization, and the linking group is a monocyclic or polycyclic hydrocarbon. You may have a structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

The alicyclic hydrocarbon-based acid-decomposable resin of the present invention may further have a repeating unit having 1 to 3 groups represented by the general formula (F1). This improves line edge roughness performance.

In general formula (F1),
R ₅₀ to R ₅₅ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R ₅₀ to R ₅₅ represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.

Rx represents a hydrogen atom or an organic group (preferably an acid-decomposable protective group, alkyl group, cycloalkyl group, acyl group, alkoxycarbonyl group).

The alkyl group of R ₅₀ to R ₅₅ may be substituted with a halogen atom such as a fluorine atom, a cyano group, or the like, and preferably an alkyl group having 1 to 3 carbon atoms such as a methyl group or a trifluoromethyl group. be able to.

R ₅₀ to R ₅₅ are preferably all fluorine atoms.

Examples of the organic group represented by Rx include an acid-decomposable protective group and an optionally substituted alkyl group, cycloalkyl group, acyl group, alkylcarbonyl group, alkoxycarbonyl group, alkoxycarbonylmethyl group, alkoxymethyl group. A 1-alkoxyethyl group is preferred.

The repeating unit having a group represented by the general formula (F1) is preferably a repeating unit represented by the following general formula (F2).

In general formula (F2),
Rx represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group of Rx may have include a hydroxyl group and a halogen atom.

Fa represents a single bond or a linear or branched alkylene group (preferably a single bond).

Fb represents a monocyclic or polycyclic hydrocarbon group.

Fc represents a single bond or a linear or branched alkylene group (preferably a single bond or a methylene group).

F ₁ represents a group represented by the general formula (F1).

P ₁ represents 1 to 3.

The cyclic hydrocarbon group in Fb is preferably a cyclopentylene group, a cyclohexylene group, or a norbornylene group.

Although the specific example of the repeating unit which has group represented by general formula (F1) is shown, this invention is not limited to this.

The alicyclic hydrocarbon-based acid-decomposable resin of the present invention may further contain a repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposability. This can reduce the elution of low molecular components from the actinic ray-sensitive or radiation-sensitive film into the immersion liquid during immersion exposure. Examples of such a repeating unit include 1-adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like.

In addition to the above repeating structural units, the alicyclic hydrocarbon-based acid-decomposable resin of the present invention has a dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolving power that is a general necessary characteristic of a resist. Various repeating structural units can be contained for the purpose of adjusting heat resistance, sensitivity, and the like.

Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.

As a result, the performance required for the alicyclic hydrocarbon-based acid-decomposable resin, in particular, (1) solubility in coating solvents, (2) film-forming properties (glass transition temperature), (3) positive developer and negative (4) film slippage (hydrophobic and alkali-soluble group selection), (5) adhesion of unexposed part to substrate, (6) dry etching resistance,
Etc. can be finely adjusted.

As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

In alicyclic hydrocarbon-based acid-decomposable resins, the molar ratio of each repeating structural unit is the resist's dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is a general required performance of resists. In order to adjust heat resistance, sensitivity, etc., it is set appropriately.

Preferred embodiments of the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention include the following.

(1) One containing a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the above general formulas (pI) to (pV) (side chain type).

Preferably, those containing (meth) acrylate repeating units having a structure of (pI) to (pV).

(2) One containing a repeating unit represented by the general formula (II-AB) (main chain type).

However, in (2), for example, the following can be further mentioned.

(3) A repeating unit represented by the general formula (II-AB), a maleic anhydride derivative and a (meth) acrylate structure (hybrid type).

The content of the repeating unit having an acid-decomposable group in the alicyclic hydrocarbon-based acid-decomposable resin is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 25 in all repeating structural units. ~ 40 mol%.

The content of the repeating unit having an acid-decomposable group in the acid-decomposable resin is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 25 to 40 mol% in all repeating structural units. is there.

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is 20 to 70 in all the repeating structural units. The mol% is preferable, more preferably 20 to 50 mol%, still more preferably 25 to 40 mol%.

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol% in all repeating structural units. More preferably, it is 20 to 50 mol%.

In the acid-decomposable resin, the content of the repeating unit having a lactone ring is preferably 10 to 70 mol%, more preferably 20 to 60 mol%, still more preferably 25 to 40 mol% in all repeating structural units.

The content of the repeating unit having an organic group having a polar group in the acid-decomposable resin is preferably 1 to 40 mol%, more preferably 5 to 30 mol%, and still more preferably 5 to 20 mol% in all repeating structural units. %.

In addition, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can also be appropriately set according to the performance of the desired resist. ) To (pV) 99 mol% based on the total number of moles of the repeating structural unit having a partial structure containing an alicyclic hydrocarbon and the repeating unit represented by the above general formula (II-AB) The following is preferable, More preferably, it is 90 mol% or less, More preferably, it is 80 mol% or less.

When the actinic ray-sensitive or radiation-sensitive resin composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

As the alicyclic hydrocarbon-based acid-decomposable resin for use in the present invention, all of the repeating units are preferably composed of (meth) acrylate-based repeating units. In this case, all of the repeating units may be methacrylate repeating units, all of the repeating units may be acrylate repeating units, and all of the repeating units may be any mixture of methacrylate repeating units / acrylate repeating units, It is preferable that the acrylate repeating unit is 50 mol% or less of the entire repeating unit.

The alicyclic hydrocarbon-based acid-decomposable resin includes at least a (meth) acrylate-based repeating unit having a lactone ring, a (meth) acrylate-based repeating unit having an organic group substituted with at least one of a hydroxyl group and a cyano group, and A copolymer having three types of repeating units of a (meth) acrylate-based repeating unit having an acid-decomposable group is preferable.

Preferably, 20 to 50 mol% of repeating units having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pV), 20 to 50 mol% of repeating units having a lactone structure, substituted with a polar group A terpolymer having 5-30% of repeating units having an alicyclic hydrocarbon structure, or a quaternary copolymer having 0-20% of other repeating units.

Particularly preferred resins include 20 to 50 mol% of repeating units having an acid-decomposable group represented by the following general formulas (ARA-1) to (ARA-7), and the following general formulas (ARL-1) to (ARL- 7) Repeating units having an alicyclic hydrocarbon structure substituted with 20 to 50 mol% of repeating units having a lactone group represented by formulas and polar groups represented by the following general formulas (ARH-1) to (ARH-3) Ternary copolymer containing 5 to 30 mol% of units, or further a carboxyl group, or a repeating unit having a structure represented by the general formula (F1), or an alicyclic hydrocarbon structure and not exhibiting acid decomposability It is a quaternary copolymer containing 5 to 20 mol% of repeating units.

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, Rxa ₁ and Rxb ₁ each independently represent a methyl group or an ethyl group, and Rxc ₁ represents a hydrogen atom or a methyl group.)

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, Rxd ₁ represents a hydrogen atom or a methyl group, and Rxe ₁ represents a trifluoromethyl group, a hydroxyl group, or a cyano group.)

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group.)

The alicyclic hydrocarbon-based acid-decomposable resin used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as the solvent used in the actinic ray-sensitive or radiation-sensitive resin composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.

The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2'-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C. to 150 ° C., preferably 30 ° C. to 120 ° C., more preferably 60 to 100 ° C.

For purification, the same method as that for the resin (C) described later can be used. The liquid-liquid extraction method for removing residual monomers and oligomer components by combining water washing and an appropriate solvent, only those having a specific molecular weight or less. A purification method in a solution state such as ultrafiltration to extract and remove the residual monomer by coagulating the resin in the poor solvent by dropping the resin solution into the poor solvent, A usual method such as a purification method in a solid state, such as washing the filtered resin slurry with a poor solvent, can be applied.

The weight average molecular weight of the resin according to the present invention is preferably 1,000 to 200,000, more preferably 1,000 to 20,000, and most preferably 1,000 to 15 in terms of polystyrene by GPC method. , 000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, and developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.

The degree of dispersion (molecular weight distribution) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and particularly preferably 1.2 to 2.0. . The smaller the degree of dispersion, the better the resolution and the resist shape, the smoother the side wall of the resist pattern, and the better the roughness.
In the actinic ray-sensitive or radiation-sensitive resin composition of the present invention, the blending amount of the acid-decomposable resin in the whole composition is preferably 50 to 99.9% by mass, more preferably 60 to 99% in the total solid content. 0.0% by mass.
In the present invention, the acid-decomposable resin may be used alone or in combination.

In the alicyclic hydrocarbon-based acid-decomposable resin of the present invention, more preferably in the actinic ray-sensitive or radiation-sensitive resin composition of the present invention, a fluorine atom is used from the viewpoint of compatibility with the protective film-forming composition. It is preferable that no silicon atom is contained.

(B) Compound that generates acid upon irradiation with actinic ray or radiation The actinic ray-sensitive or radiation-sensitive resin composition of the present invention is a compound that generates acid upon irradiation with actinic ray or radiation ("photoacid generator" or (Also referred to as “compound (B)”).

Examples of such photoacid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, actinic rays used in microresists, etc. Known compounds that generate an acid upon irradiation with radiation and mixtures thereof can be appropriately selected and used.

Examples include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A 62-153853, The compounds described in, for example, Kokai 63-146029 can be used.

Furthermore, compounds capable of generating an acid by light as described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) can be exemplified.

In the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.

X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ^{− and the} like. Preferably, it is an organic anion containing a carbon atom.

Preferred organic anions include organic anions represented by the following formula.

Where
Rc ₁ represents an organic group.

Examples of the organic group in Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, an aryl group, or a plurality of these optionally substituted are a single bond, —O—, —CO ₂ —, — And groups connected by a linking group such as S—, —SO ₃ —, and —SO ₂ N (Rd ₁ ) —. Rd ₁ represents a hydrogen atom or an alkyl group.

Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group. Preferred examples of the organic group for Rc ₃ , Rc ₄ and Rc ₅ include the same organic groups as those for Rc ₁ , and most preferred is a perfluoroalkyl group having 1 to 4 carbon atoms.

Rc ₃ and Rc ₄ may combine to form a ring. Examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group and an arylene group. A perfluoroalkylene group having 2 to 4 carbon atoms is preferred.

The organic group of Rc ₁ and Rc ₃ to Rc ₅ is particularly preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved. Further, when Rc ₃ and Rc ₄ are combined to form a ring, the acidity of the acid generated by light irradiation is increased, and the sensitivity is improved.

The organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

Further, two members out of R ₂₀₁ to R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. Examples of the group formed by combining two of R ₂₀₁ to R ₂₀₃ include an alkylene group (eg, butylene group, pentylene group).

Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

In addition, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, the general formula R ₂₀₁ ~ R ₂₀₃ of a compound represented by (ZI) at least one is, the structures attached to at least one of the general formulas (ZI) of another compound represented by R ₂₀₁ ~ R ₂₀₃ It may be a compound.

More preferred (ZI) components include compounds (ZI-1), (ZI-2), and (ZI-3) described below.

The compound (ZI-1) is an arylsulfonium compound in which at least one of R ₂₀₁ to R _{203 in} the general formula (ZI) is an aryl group, that is, a compound having arylsulfonium as a cation.

In the arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be an aryl group, or a part of R ₂₀₁ to R ₂₀₃ may be an aryl group with the remaining being an alkyl group or a cycloalkyl group.

Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkylsulfonium compound, an aryldialkylsulfonium compound, a diarylcycloalkylsulfonium compound, and an aryldicycloalkylsulfonium compound.

The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, more preferably a phenyl group or an indole residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

The alkyl group that the arylsulfonium compound optionally has is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.

The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

The aryl group, alkyl group, and cycloalkyl group of R ₂₀₁ to R ₂₀₃ are an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms). , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, and particularly preferable. Is an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R ₂₀₁ to R ₂₀₃ , or may be substituted with all three. Further, when R ₂₀₁ to R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (ZI-2) will be described. Compound (ZI-2) is a compound in the case where R ₂₀₁ to R ₂₀₃ in formula (ZI) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

The organic group not containing an aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R ₂₀₁ to R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group or a vinyl group, more preferably a linear, branched or cyclic 2-oxoalkyl group or an alkoxycarbonylmethyl group, particularly preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (eg, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ is preferably a linear or branched 2-oxoalkyl group or an alkoxycarbonylmethyl group.

Preferred _examples of the cycloalkyl group as R ₂₀₁ to R ₂₀₃ include cycloalkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a cyclic 2-oxoalkyl group.

The linear, branched and cyclic 2-oxoalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a group having> C═O at the 2-position of the above alkyl group or cycloalkyl group.

The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R ₂₀₃ is preferably an alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group).

R ₂₀₁ to R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

The compound (ZI-3) is a compound represented by the following general formula (ZI-3), and is a compound having a phenacylsulfonium salt structure.

In general formula (ZI-3),
R _1c to R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom.

R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.

Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group.

Any two or more of R _1c to R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom, a sulfur atom, an ester bond, and an amide bond. May be included. Examples of the group formed by combining any two or more of R _1c to R _7c and R _x and R _y include a butylene group and a pentylene group.

X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

The alkyl group as R _1c to R _7c may be linear or branched, for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. Or a linear or branched alkyl group (for example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, or a linear or branched pentyl group).

The cycloalkyl group as R _1c to R _7c is preferably a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group or a cyclohexyl group).

The alkoxy group as R _1c to R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), cyclic alkoxy group having 3 to 8 carbon atoms (for example, cyclopentyloxy group, cyclohexyloxy group) ).

Preferably, any one of R _1c to R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _1c to R _5c is 2. ~ 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _1c to R _7c . The alkyl group as R _x and R _y is preferably a linear or branched 2-oxoalkyl group or an alkoxycarbonylmethyl group.

_Examples of the cycloalkyl group as R _x and R _y include the same cycloalkyl groups as R _1c to R _7c . The cycloalkyl group as R _x and R _y is preferably a cyclic 2-oxoalkyl group.

Examples of the linear, branched and cyclic 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _1c to R _7c .

Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _1c to R _5c .

R _x and R _y are preferably an alkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more.

In general formulas (ZII) and (ZIII),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.

The aryl group of R ₂₀₄ to R ₂₀₇ is preferably a phenyl group or a naphthyl group, more preferably a phenyl group.

The alkyl group as R ₂₀₄ to R ₂₀₇ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group).

The cycloalkyl group as R ₂₀₄ to R ₂₀₇ preferably includes a cycloalkyl group having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group).

R ₂₀₄ to R ₂₀₇ may have a substituent. Examples of the substituent that R ₂₀₄ to R ₂₀₇ may have include, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 6 carbon atoms). 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

Among the compounds that generate acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZIV), (ZV), and (ZVI) can be further exemplified.

In the general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.

R ₂₂₆ represents an alkyl group or an aryl group.

R ₂₂₇ and R ₂₂₈ each independently represents an alkyl group, an aryl group, or an electron-withdrawing group. R ₂₂₇ is preferably an aryl group.

R ₂₂₈ is preferably an electron-withdrawing group, more preferably a cyano group or a fluoroalkyl group.

A represents an alkylene group, an alkenylene group or an arylene group.

As the compound that generates an acid upon irradiation with actinic rays or radiation, compounds represented by general formulas (ZI) to (ZIII) are preferable.

The compound (B) is preferably a compound that generates an aliphatic sulfonic acid having a fluorine atom or a benzenesulfonic acid having a fluorine atom upon irradiation with actinic rays or radiation.

Compound (B) preferably has a triphenylsulfonium structure.

The compound (B) is preferably a triphenylsulfonium salt compound having an alkyl group or a cycloalkyl group not substituted with fluorine in the cation moiety.

Examples of particularly preferred compounds that generate an acid upon irradiation with actinic rays or radiation are listed below.

The photoacid generator can be used alone or in combination of two or more. When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.

The content of the photoacid generator is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably based on the total solid content of the actinic ray-sensitive or radiation-sensitive resin composition. Is 1 to 7% by mass. By setting the content of the photoacid generator within this range, the exposure margin when the resist pattern is formed and the crosslinking reactivity with the crosslinked layer forming material are improved.

(C) Solvent The actinic ray-sensitive or radiation-sensitive resin composition of the present invention may contain a solvent. Solvents that can be used when preparing the actinic ray-sensitive or radiation-sensitive resin composition by dissolving the above components include, for example, alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate Mention may be made of esters, alkyl alkoxypropionates, cyclic lactones having 4 to 10 carbon atoms, monoketone compounds having 4 to 10 carbon atoms which may contain rings, organic solvents such as alkylene carbonates, alkyl alkoxyacetates and alkyl pyruvates. Can do.

Examples of the alkylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl Preferred examples include ether propionate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate.

Preferred examples of the alkylene glycol monoalkyl ether include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether.

Preferred examples of the alkyl lactate include methyl lactate, ethyl lactate, propyl lactate and butyl lactate.

Preferred examples of the alkyl alkoxypropionate include ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate and ethyl 3-methoxypropionate.

Examples of the cyclic lactone having 4 to 10 carbon atoms include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ- Preferred are caprolactone, γ-octanoic lactone, and α-hydroxy-γ-butyrolactone.

Examples of monoketone compounds having 4 to 10 carbon atoms and which may contain a ring include 2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone, 3-methyl-2-pentanone, 4- Methyl-2-pentanone, 2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2 -Hexanone, 3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4 -Heptanone, 2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5 Hexen-2-one, 3-penten-2-one, cyclopentanone, 2-methylcyclopentanone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopenta Non, cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone, 2-methylcyclo Preferred are heptanone and 3-methylcycloheptanone.

Preferred examples of the alkylene carbonate include propylene carbonate, vinylene carbonate, ethylene carbonate, and butylene carbonate.

Examples of the alkyl alkoxyacetate include 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2- (2-ethoxyethoxy) ethyl acetate, 3-methoxy-3-methylbutyl acetate, and 1-methoxy-acetate. 2-propyl is preferred.

Preferred examples of the alkyl pyruvate include methyl pyruvate, ethyl pyruvate, and propyl pyruvate.

As a solvent that can be preferably used, a solvent having a boiling point of 130 ° C. or higher under normal temperature and normal pressure can be mentioned. Specifically, cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethyl acetate, acetic acid Examples include -2- (2-ethoxyethoxy) ethyl and propylene carbonate. Butyl butanoate, isoamyl acetate, methyl 2-hydroxyisobutyrate may be used as a solvent.

In the present invention, the above solvents may be used alone or in combination of two or more.

In the present invention, a mixed solvent obtained by mixing a solvent containing a hydroxyl group in the structure and a solvent not containing a hydroxyl group may be used as the organic solvent.

Examples of the solvent containing a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Particularly preferred are propylene glycol monomethyl ether and ethyl lactate.

Examples of the solvent not containing a hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide, etc. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are particularly preferable, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate. 2-heptanone is most preferred.

The mixing ratio (mass) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. . A mixed solvent containing 50% by mass or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.

The solvent is preferably a mixed solvent of two or more containing propylene glycol monomethyl ether acetate.

(D) Basic compound The actinic ray-sensitive or radiation-sensitive resin composition of the present invention preferably contains (E) a basic compound in order to reduce the change in performance over time from exposure to heating.

Preferred examples of the basic compound include compounds having structures represented by the following formulas (A) to (E).

In general formulas (A) to (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different, and are a hydrogen atom, an alkyl group (preferably having a carbon number of 1 to 20), a cycloalkyl group (preferably having a carbon number of 3 to 20) or an aryl group (having a carbon number). 6-20), wherein R ²⁰¹ and R ²⁰² may combine with each other to form a ring.

Regarding the alkyl group, the alkyl group having a substituent is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms.

R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms.

These alkyl groups in general formulas (A) to (E) are more preferably unsubstituted.

Preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine and the like, and more preferred compounds include imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate Examples thereof include a compound having a structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, and an aniline derivative having a hydroxyl group and / or an ether bond.

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole and the like. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4,0. ] Undecar 7-ene and the like. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically, triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium. Examples thereof include hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. The compound having an onium carboxylate structure is a compound having an onium hydroxide structure in which the anion moiety is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of aniline compounds include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

These basic compounds may be used alone or in combination of two or more.

The amount of the basic compound used is usually 0.001 to 10% by mass, preferably 0.01 to 5% by mass, based on the solid content of the actinic ray-sensitive or radiation-sensitive resin composition.

The use ratio of the acid generator and the basic compound in the composition is preferably acid generator / basic compound (molar ratio) = 2.5 to 300. In other words, the molar ratio is preferably 2.5 or more from the viewpoint of sensitivity and resolution, and is preferably 300 or less from the viewpoint of suppressing the reduction in resolution due to the thickening of the resist pattern over time until post-exposure heat treatment. The acid generator / basic compound (molar ratio) is more preferably from 5.0 to 200, still more preferably from 7.0 to 150.

(E) Hydrophobic resin The actinic ray-sensitive or radiation-sensitive resin composition of the present invention may further contain a hydrophobic resin. As the hydrophobic resin, a resin having at least one of a fluorine atom, a silicon atom, and a CH ₃ partial structure contained in a side chain portion of the resin can be suitably used. Specifically, the same resin as the resin (X) contained in the protective film-forming composition described above can be used.

(F) Surfactant The actinic ray-sensitive or radiation-sensitive resin composition of the present invention preferably further contains (F) a surfactant, and is a fluorine-based and / or silicon-based surfactant (fluorine-based interface). It is more preferable to contain at least one of an activator, a silicon-based surfactant, and a surfactant having both a fluorine atom and a silicon atom.

When the actinic ray-sensitive or radiation-sensitive resin composition of the present invention contains the above-mentioned (F) surfactant, adhesion with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. In addition, a resist pattern with few development defects can be provided.

Examples of the fluorine-based and / or silicon-based surfactant include JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.

Examples of commercially available surfactants that can be used include EFTOP EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 and 4430 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176 and F189. F113, F110, F177, F120, R08 (manufactured by Dainippon Ink & Chemicals, Inc.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (Manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (manufactured by Toagosei Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), F-top EF121, EF122A, EF122B, RF122C, EF125M , EF135M, EF351, 352, EF801, EF802, E 601 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 (manufactured by OMNOVA), FTX-204D, 208G, 218G, 230G, 204D, 208D, 212D, 218, 222D (manufactured by Neos) Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

For example, as a commercially available surfactant, Megafac F178, F-470, F-473, F-475, F-476, F-472 (manufactured by Dainippon Ink & Chemicals, Inc.) can be mentioned. Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₃ F ₇ group and (poly (oxy) And a copolymer of (ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate).

In the present invention, other surfactants other than fluorine-based and / or silicon-based surfactants can also be used. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, etc. Sorbitans such as polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopal Te - DOO, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, may be mentioned polyoxyethylene sorbitan tristearate nonionic surfactants of polyoxyethylene sorbitan fatty acid esters such as such.

These surfactants may be used alone or in some combination.

(F) The amount of the surfactant used is preferably 0.01 to 10% by mass, more preferably 0.1 to 5%, based on the total amount of the actinic ray-sensitive or radiation-sensitive resin composition (excluding the solvent). % By mass.

(G) Carboxylic acid onium salt The actinic ray-sensitive or radiation-sensitive resin composition in the present invention may contain (G) a carboxylic acid onium salt. Examples of the carboxylic acid onium salt include a carboxylic acid sulfonium salt, a carboxylic acid iodonium salt, and a carboxylic acid ammonium salt. In particular, the (G) carboxylic acid onium salt is preferably an iodonium salt or a sulfonium salt. Furthermore, it is preferable that the carboxylate residue of the (H) carboxylic acid onium salt of the present invention does not contain an aromatic group or a carbon-carbon double bond. A particularly preferred anion moiety is a linear, branched, monocyclic or polycyclic alkylcarboxylic acid anion having 1 to 30 carbon atoms. More preferably, an anion of a carboxylic acid in which some or all of these alkyl groups are fluorine-substituted is preferable. The alkyl chain may contain an oxygen atom. This ensures transparency with respect to light of 220 nm or less, improves sensitivity and resolution, and improves density dependency and exposure margin.

Fluoro-substituted carboxylic acid anions include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorocyclohexanecarboxylic acid, 2 , Anions of 2-bistrifluoromethylpropionic acid, and the like.

These (G) carboxylic acid onium salts can be synthesized by reacting sulfonium hydroxide, iodonium hydroxide, ammonium hydroxide and carboxylic acid with silver oxide in a suitable solvent.

The content of (G) carboxylic acid onium salt in the composition is generally 0.1 to 20% by mass, preferably 0.5 to 10% by mass, more preferably 1%, based on the total solid content of the composition. -7% by mass.

(H) Other additives The actinic ray-sensitive or radiation-sensitive resin composition of the present invention may further include a dye, a plasticizer, a photosensitizer, a light absorber, an alkali-soluble resin, and a dissolution inhibitor, as necessary. And a compound (for example, a phenol compound having a molecular weight of 1000 or less, an alicyclic group having a carboxyl group, or an aliphatic compound) that promotes solubility in a developer.

Such a phenol compound having a molecular weight of 1000 or less can be obtained by referring to, for example, the methods described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, etc. It can be easily synthesized by those skilled in the art.

Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

The organic solvent developer, alkali developer and / or rinsing solution that can be used in the present invention preferably have few impurities such as various fine particles and metal elements. In order to obtain such chemicals with few impurities, these chemicals are manufactured in a clean room, and filtered with various filters such as Teflon (registered trademark) filters, polyolefin filters, ion exchange filters, etc. It is preferable to reduce impurities. As for the metal element, the metal element concentrations of Na, K, Ca, Fe, Cu, Mg, Mn, Li, Al, Cr, Ni, and Zn are all preferably 10 ppm or less, and preferably 5 ppm or less. More preferred.

The storage container for the developer and the rinsing liquid is not particularly limited, and containers such as polyethylene resin, polypropylene resin, and polyethylene-polypropylene resin that are used for electronic materials can be used as appropriate. In order to reduce impurities eluted from the container, it is also preferable to select a container having a small amount of components eluted from the inner wall of the container into the chemical solution. As such a container, a container whose inner wall is made of perfluoro resin (for example, FluoroPure PFA composite drum (wetted inner surface; PFA resin lining) manufactured by Entegris), steel drum can manufactured by JFE (wetted inner surface; zinc phosphate coating) ) And the like.

Various materials used in the actinic ray-sensitive or radiation-sensitive resin composition of the present invention and the pattern forming method of the present invention (for example, a developer, a rinsing liquid, a composition for forming an antireflection film, and for forming a top coat) The composition or the like preferably does not contain impurities such as metals. The content of the metal component contained in these materials is preferably 10 ppm or less, more preferably 5 ppm or less, still more preferably 1 ppm or less, and particularly preferably (not more than the detection limit of the measuring device). .

As a method for removing impurities such as metals from the above various materials, for example, filtration using a filter can be mentioned. The pore size of the filter is preferably 50 nm or less, more preferably 10 nm or less, and still more preferably 5 nm or less. As a material of the filter, a filter made of polytetrafluoroethylene, polyethylene, or nylon is preferable. In the filter filtration step, a plurality of types of filters may be connected in series or in parallel. When a plurality of types of filters are used, filters having different pore diameters and / or materials may be used in combination. Moreover, various materials may be filtered a plurality of times, and the step of filtering a plurality of times may be a circulating filtration step.

Moreover, as a method for reducing impurities such as metals contained in the various materials, a raw material having a low metal content is selected as a raw material constituting the various materials, and filter filtration is performed on the raw materials constituting the various materials. And the like. The preferable conditions for filter filtration performed on the raw materials constituting the various materials are the same as those described above.

In addition to filter filtration, impurities may be removed by an adsorbent, or filter filtration and an adsorbent may be used in combination. As the adsorbent, known adsorbents can be used. For example, inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon can be used.

The pattern formed by the method of the present invention is typically used as a mask in an etching process of semiconductor manufacturing, but can be used for other purposes. Other uses include guide pattern formation in DSA (Directed Self-Assembly) (see ACS Nano Vol. 4, No. 8, Page 4815-4823, etc.), use as a core material (core) of a so-called spacer process (for example, JP-A-3 -270227 and JP2013-164509A).

The present invention also relates to an electronic device manufacturing method including the pattern forming method of the present invention described above.
The electronic device obtained by the method for producing an electronic device of the present invention is suitably mounted on an electric / electronic device (home appliance, OA / media related device, optical device, communication device, etc.).

Hereinafter, the present invention will be described in detail by way of examples, but the contents of the present invention are not limited thereto.

<Synthesis of Resin (X)>
Resins X-1 to X27 shown below were synthesized by a method in accordance with paragraph 0521 of JP 2013-218223 A.

<Synthesis of acid-decomposable resin>
Synthesis Example: Synthesis of Resin (1) 102.3 parts by mass of cyclohexanone was heated to 80 ° C. under a nitrogen stream. While stirring this solution, 22.2 parts by mass of a monomer represented by the following structural formula M-1, 22.8 parts by mass of a monomer represented by the following structural formula M-2, and represented by the following structural formula M-3 A mixed solution of 6.6 parts by mass of monomer, 189.9 parts by mass of cyclohexanone, dimethyl 2,2′-azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] over 5 hours It was dripped. After completion of dropping, the mixture was further stirred at 80 ° C. for 2 hours. The reaction solution was allowed to cool, then reprecipitated and filtered with a large amount of hexane / ethyl acetate (mass ratio 9: 1), and the obtained solid was vacuum-dried to obtain 41.1 parts by mass of Resin (1). .

The weight average molecular weight (Mw: converted to polystyrene) obtained from GPC (carrier: tetrahydrofuran (THF)) of the obtained resin (1) was Mw = 9500, and the dispersity was Mw / Mn = 1.62. ^The composition ratio measured by ¹³ C-NMR was 40/50/10 in molar ratio.

The same operations as in the above synthesis example were performed to synthesize the following resins (2) to (12) as acid-decomposable resins.

[Preparation of resist composition]
The components shown in Table 1 were dissolved in a solvent, and a solution having a solid concentration of 3.5% by mass was prepared for each, and this was filtered through a polyethylene filter having a pore size of 0.03 μm to prepare a resist composition.

The following abbreviations are used in the table.

<Acid-decomposable resin>

The composition ratio (molar ratio; corresponding in order from the left), weight average molecular weight (Mw), and dispersity (Mw / Mn) of each repeating unit are shown in Table 2 below. These were calculated | required by the method similar to resin (1) mentioned above.

<Photoacid generator>

<Basic compound>
The following compounds were used as acid diffusion control agents.

<Hydrophobic resin>
As the hydrophobic resin, the following resins were used.

Table 3 shows the composition ratio (molar ratio; corresponding in order from the left), weight average molecular weight (Mw), and dispersity (Mw / Mn) of each repeating unit. These were calculated | required by the method similar to resin (1) mentioned above.

<Surfactant>
W-1: Megafuck F176 (manufactured by DIC Corporation) (fluorine-based)
W-2: Megafuck R08 (manufactured by DIC Corporation) (fluorine and silicon)
W-3: PF6320 (manufactured by OMNOVA Solutions Inc.) (fluorine-based)
<Solvent>
A1: Propylene glycol monomethyl ether acetate (PGMEA)
A2: Cyclohexanone A3: γ-Butyrolactone B1: Propylene glycol monomethyl ether (PGME)
[Preparation of composition for forming protective film]
The components shown in Table 4 were dissolved in 4-methyl-2-pentanol, and a solution with a solid content of 2.7% by mass was prepared for each, and this was filtered through a polyethylene filter having a pore size of 0.03 μm, as with the resist. Thus, a composition for forming a protective film was prepared.

The following abbreviations are used in the table.

<Resin (X)>
Each repeating unit contained in the resins X1 to X29 is as follows. The composition ratio (molar ratio), weight average molecular weight (Mw), and dispersity (Mw / Mn) of each repeating unit in the resins X1 to X29 were determined by the same method as the resin (1) described above.

[Repeating unit having proton acceptor functional group]

[Other repeat units]

<Low molecular basic compounds>
As a control compound, the following low molecular weight basic compound TQ-100 was used.

[Hole pattern formation]
An organic antireflection film ARC29SR (manufactured by Brewer) is applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a film thickness of 86 nm, on which an actinic ray-sensitive or radiation-sensitive resin composition is formed. The product was applied and baked (PB: Prebake) at 100 ° C. for 60 seconds to form a resist film having a thickness of 90 nm. Furthermore, the composition for protective film formation was apply | coated, and it baked for 60 second at the temperature of Table 5, and formed the protective film which has the film thickness of the table.

The obtained wafer was used with an ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA 1.20, C-Quad, outer sigma 0.730, inner sigma 0.630, XY deflection), and the hole portion was 65 nm. Pattern exposure was performed through a square array halftone mask having a pitch between holes of 100 nm. Ultra pure water was used as the immersion liquid. Then, it heated at 105 degreeC for 60 second (PEB: Post Exposure Bake). Subsequently, development was carried out by paddling with an organic solvent-based developer described in Table 5 for 30 seconds, and paddle was rinsed for 30 seconds with a rinse solution described in the same table. However, for Example 28, the rinsing step was not performed. Subsequently, the wafer was rotated at 2000 rpm for 30 seconds to obtain a hole pattern with a hole diameter of 50 nm.

[Formation of line and space pattern]
An organic antireflection film ARC29SR (manufactured by Brewer) is applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a film thickness of 86 nm, on which an actinic ray-sensitive or radiation-sensitive resin composition is formed. The product was applied and baked (PB: Prebake) at 100 ° C. for 60 seconds to form a resist film having a thickness of 90 nm. Further, a protective film-forming composition was applied and baked at the temperature shown in Table 5 for 60 seconds to form a protective film having the film thickness shown in the same table.

The obtained wafer was used with an ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA1.20, Dipole, outer sigma 0.800, inner sigma 0.564, Y deflection) with a space portion of 55 nm and a hole. Pattern exposure was performed through a halftone mask having a pitch of 110 nm therebetween. Ultra pure water was used as the immersion liquid. Then, it heated at 105 degreeC for 60 second (PEB: Post Exposure Bake). Subsequently, development was carried out by paddling with an organic solvent-based developer described in Table 5 for 30 seconds, and paddle was rinsed for 30 seconds with a rinse solution described in the same table. However, for Example 28, the rinsing step was not performed. Subsequently, the wafer was rotated at a rotational speed of 2000 rpm for 30 seconds to obtain a line pattern having a line width of 50 nm.

[Evaluation]
<Focus margin (DOF: Depth of Focus)>
Under the exposure / development conditions in the above “hole pattern formation”, exposure and development are performed by changing the exposure focus conditions in steps of 20 nm in the focus direction at the exposure amount for forming a hole pattern with a hole diameter of 50 nm. The hole diameter (Critical Dimension: CD) of the pattern was measured using a line width measurement scanning electron microscope SEM (Hitachi, Ltd. S-9380), and the minimum of the curve obtained by plotting each of the above CDs The focus corresponding to the value or the maximum value was set as the best focus. When the focus was changed around the best focus, a focus fluctuation range allowing a hole diameter of 50 nm ± 10%, that is, a focus margin (DOF) (nm) was calculated. The evaluation results are shown in Table 5.

<Line edge roughness (LER)>
With the exposure amount for forming a line pattern with a line width of 50 nm under the exposure and development conditions of “line and space pattern formation” described above, the line edge roughness is measured using a length measuring scanning electron microscope (SEM). The pattern was observed, and the distance from the reference line where the edge should be in the range where the edge of the line pattern in the longitudinal direction is 5 μm was measured at 50 points by the length measuring SEM, the standard deviation was obtained, and 3σ (nm) was calculated. A smaller value indicates better performance. The evaluation results are shown in Table 5.

<Exposure margin (EL: Exposure Latitude)>
Under the exposure / development conditions of the above “hole pattern formation”, the exposure amount that reproduces the hole diameter (Critical Dimension: CD) with a hole diameter of 50 nm is the optimum exposure amount, and when the exposure amount is changed, the hole diameter is 50 nm ± 10 The exposure amount width that allowed% was obtained, and this value was divided by the optimum exposure amount and displayed as a percentage. The larger the value, the smaller the change in performance due to the change in exposure amount, and the better the exposure margin. The evaluation results are shown in Table 5.

From the results of Table 5, it can be seen that the pattern obtained by the pattern forming method of the present invention has excellent focus margin (DOF) and exposure margin (EL), and also has suppressed line width variation (LER). .

Claims (9)

1. (a) applying an actinic ray-sensitive or radiation-sensitive resin composition on a substrate to form an actinic ray-sensitive or radiation-sensitive film;
   (b) applying a protective film-forming composition on the actinic ray-sensitive or radiation-sensitive film to form a protective film;
   (c) exposing the actinic ray-sensitive or radiation-sensitive film coated with the protective film, and (d) developing the exposed actinic ray-sensitive or radiation-sensitive film with an organic solvent. A pattern forming method including a step of developing with a liquid,
   The pattern formation method in which the said protective film contains resin (X) which has a proton acceptor functional group.
2. The pattern forming method according to claim 1, wherein the proton acceptor functional group is a functional group containing a nitrogen atom constituting an aliphatic amine, an aromatic amine or a heterocyclic amine.
3. The pattern forming method according to claim 1, wherein the proton acceptor functional group is an ether bond, a thioether bond, a carbonyl bond or a thiocarbonyl bond.
4. Resin (X) contains a repeating unit having the proton acceptor functional group, and the content of the repeating unit is 0.1 to 10 mol% with respect to all repeating units in the resin (X). The pattern forming method according to any one of claims 1 to 3.
5. 5. The pattern forming method according to claim 1, wherein the resin (X) is a resin that substantially does not contain a fluorine atom.
6. After the step (b) for forming the protective film and before the step (c) for exposing, a step of heating the substrate coated with the actinic ray-sensitive or radiation-sensitive film and the protective film at 100 ° C. or higher The pattern forming method according to claim 1, further comprising:
7. A protective film-forming composition used for forming a protective film for coating an actinic ray-sensitive or radiation-sensitive film, comprising a resin (X) having a proton acceptor functional group, wherein the proton acceptor property The composition for protective film formation whose functional group is a functional group containing the nitrogen atom which comprises an aliphatic amine, an aromatic amine, or a heterocyclic amine.
8. A protective film-forming composition used for forming a protective film for coating an actinic ray-sensitive or radiation-sensitive film, comprising a resin (X) having a proton acceptor functional group, wherein the proton acceptor property A composition for forming a protective film, wherein the functional group is an ether bond, a thioether bond, a carbonyl bond or a thiocarbonyl bond.
9. An electronic device manufacturing method including the pattern forming method according to any one of claims 1 to 6.