TW201732429A - Resist composition, resist film, mask blank, pattern forming method, and method for manufacturing electronic device - Google Patents

Abstract

The present invention provides: a resist composition which contains a resin (P) that has a repeating unit (a) having an inner salt structure; a resist film which is formed from this resist composition; a mask blank; a pattern forming method which uses this resist composition; and a method for manufacturing an electronic device, which comprises this pattern forming method.

Description

Resist composition, resist film, blank mask, pattern forming method, and method of manufacturing electronic component

The present invention relates to a resist composition, a resist film, a blank mask, a pattern forming method, and a method of manufacturing an electronic component. More specifically, the present invention relates to a semiconductor manufacturing process such as an integrated circuit (IC), a circuit board such as a liquid crystal or a thermal head, and further photofabrication. A resist composition, a resist film, a blank mask, a pattern forming method, and a method of manufacturing an electronic component which can be used in the lithography step.

Conventionally, in the manufacturing process of a semiconductor element such as an IC or a large scale integrated circuit (LSI), fine processing is performed by using a lithography of a resist composition. With the high integration of integrated circuits, it is increasingly required to form ultra-fine patterns of submicron regions or quarter micron regions. As a result, it has been found that the exposure wavelength also tends to be shorter in wavelength from the g-ray to the i-ray and further to the excimer laser light (KrF, ArF). Further, in addition to excimer laser light, lithography using electron beam (EB) or X-ray or EUV light (Extreme Ultra Violet) is currently under development. In view of such a situation, various compositions have been proposed as the resist composition. For example, Patent Document 1 discloses a resist composition containing a resin having irradiation with actinic rays or radiation. And a repeating unit that generates an acid group and a proton acceptor group. Further, Patent Document 2 discloses a resist composition comprising a resin having a repeating unit having an amine structure and a resin having a repeating unit having a sulfonium salt structure. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-7892 [Patent Document 2] Japanese Patent Laid-Open No. 2015-14798

[Problems to be Solved by the Invention] However, recently, various electronic devices are required to be further highly functionalized, and it is required to produce finer wiring, and accordingly, pattern resolution and line width roughness (LWR) are required. Improved performance. Further, as a resist composition, in order to suppress defects, a resist composition having a small number of particles is required. Accordingly, an object of the present invention is to provide a resist composition, a resist film using the resist composition, a blank mask, a pattern forming method, and a method of manufacturing an electronic component, the resist composition In particular, when an ultrafine (for example, a line width of 50 nm) pattern is formed, a pattern excellent in resolution and LWR performance can be formed, and the number of particles is small. [Means for solving the problem]

The acid generated in the exposed portion diffuses to the unexposed portion, and even if the reaction between the resin and the acid occurs in the unexposed portion, the dissolution contrast is lowered. Therefore, the chemically amplified resist composition is used to capture the acid in the unexposed portion. It usually contains a basic compound (quencher). However, when the basic compound is unevenly unevenly present in the surface of the resist film or eluted into the immersion liquid or the like in the immersion exposure, the function of capturing the acid in the unexposed portion is lost. Therefore, there is a problem that the contrast ratio of the exposed portion and the unexposed portion to the developer is lowered, the boundary portion of the pattern is partially dissolved in the developer, the exposure latitude (EL) is lowered, the LWR performance is lowered, and the resolution is lowered. . It is known that a low molecular compound having an intramolecular salt structure is excellent in LWR performance and improvement in EL, but there is a limit in the introduction of a resist composition from the viewpoint of cohesiveness and solubility. In the present invention, the problem of cohesiveness and solubility is overcome by introducing an intramolecular salt structure into a repeating unit of a resin. Further, by the effect of introduction into the resin, the quenching agent is uniformly distributed in the surface of the resist film, and the diffusion of acid can be prevented. Further, as described above, since the acid can be reliably trapped in the unexposed portion, it is difficult to carry out a reaction in which a polar group is generated by the action of an acid in the resin in the unexposed portion. Therefore, it is considered that the exposed portion or the unexposed portion is surely removed by the alkaline developing solution or the developing solution containing the organic solvent, and thus the resolution is excellent. Therefore, it is considered that a pattern having excellent high resolution and LWR performance can be obtained. The inventors of the present invention have found that the above problems can be solved by the following means.

<1> A resist composition containing a resin (P) containing a repeating unit (a) having an intramolecular salt structure. <2> The resist composition according to <1>, wherein the intramolecular salt structure is the following general formula (U-1), general formula (U-2), or general formula (U-3) Any of the structures represented;

[Chemical 1]

In the general formula (U-1), the general formula (U-2), and the general formula (U-3), E ₁ and E ₂ represent a structure having a cation, and G ₁ and G ₂ represent a structure having an anion, and L ⁰ represents A single bond or a linking group; * indicates a linking site to the polymer main chain or side chain of the resin (P). <3> The resist composition according to <1>, wherein the repeating unit (a) is represented by the following general formula (i) or (ii);

[Chemical 2]

In the general formula (i) and the general formula (ii), Y ₁ , Y ₂ , R ₁₀₁ , R ₁₀₂ , R ₁₀₃ and R ₁₀₄ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, a nitro group or an organic group. L ₁ to L ₄ , Z ₁ and Z ₂ each independently represent a single bond or a divalent linking group; E ₁ and E ₂ represent a structure having a cation, and G ₁ and G ₂ represent a structure having an anion. The resist composition according to any one of <1> to <3> wherein the repeating unit (a) is represented by the following general formula (i-1) and (i-2) , represented by formula (i-3) or formula (ii-1);

[Chemical 3]

In the general formula (i-1), the general formula (i-2), the general formula (i-3), and the general formula (ii-1), Y ₁ , Y ₂ , R ₁₀₁ , R ₁₀₂ , R ₁₀₃ and R ₁₀₄ Each independently represents a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, a nitro group or an organic group; L ₁ to L ₄ , Z ₁ and Z ₂ each independently represent a single bond or a divalent linking group; and E ₁ represents a cation; , G ₁ represents a structure having an anion; R ₄₁ to R ₄₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and R ₄₁ and R ₄₂ may be bonded to each other to form a structure. Ring structure; R ₅₀ represents a substituent, k represents an integer of 0 to 4; and when k represents an integer of 2 or more, R ₅₀ may be the same or different. <5> The resist composition according to <4>, wherein the E ₁ is a group represented by the following (e1-1) or (e1-2), and the G ₁ is the following (g1- a base represented by any of 1) to (g1-5);

[Chemical 4]

In (e1-1) or (e1-2), R ₃₁ to R ₃₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and R ₃₁ and R ₃₂ may be bonded to each other. And forming a ring structure; * indicates a joint portion to L ₄ ;

[Chemical 5]

In (g1-1) to (g1-5), * indicates a connection site to L ₂ . The resist composition according to any one of <1> to <5> wherein the resin (P) further comprises a repeating unit (b) represented by the following formula (A);

[Chemical 6]

In the above formula (A), R ₁₁ , R ₁₂ and R ₁₃ each independently represent a hydrogen atom, an alkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group; wherein R ₁₂ may bond with L to form a ring And R _{12 in} this case represents a single bond or an alkylene group; X represents a single bond, -COO-, or -CONR ₃₀ -, R ₃₀ represents a hydrogen atom or an alkyl group; L represents a single bond or an alkyl group; The m-valent aromatic ring group represents an (m+1)-valent aromatic ring group when bonded to R ₁₂ to form a ring; and Z may have a hydroxyl group as a substituent; and m represents an integer of 1 to 5. The resist composition according to any one of <1> to <6> wherein the resin (P) contains a structure having a deprotection group in which a polar group is decomposed and desorbed by the action of an acid. Repeat unit (c). <8> The resist composition according to <7>, wherein the repeating unit (c) is a repeating unit represented by the following formula (AI) or formula (AII);

[化17]

In the general formula (AI) or the general formula (AII), Xa ₁ represents a hydrogen atom or an alkyl group; T represents a single bond or a divalent linking group; and Y represents a group which is desorbed by the action of an acid, and represents a group derived from -C(R). ₃₆ ) a group represented by (R ₃₇ )(OR ₃₈ ); R ₃₆ to R ₃₈ each independently represent a hydrogen atom or a monovalent organic group; R ₃₇ and R ₃₈ may be bonded to each other to form a ring; R ₆₁ , R ₆₂ and R ₆₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group; wherein R ₆₂ may be bonded to Ar ₆ to form a ring, in which case R ₆₂ represents a single bond or an alkyl group; X ₆ represents a single bond, -COO-, or -CONR ₆₄ -; R ₆₄ represents a hydrogen atom or an alkyl group; L ₆ represents a single bond or an alkyl group; and Ar ₆ represents (n+ 1) a valent aromatic ring group, in the case of bonding to R ₆₂ to form a ring, represents an (n+2)-valent aromatic ring group; in the case of n≧2, Y ₂ independently represents a hydrogen atom or a group which is desorbed by the action of an acid; wherein at least one of Y ₂ represents a group which is desorbed by the action of an acid, and represents a group represented by -C(R ₃₆ )(R ₃₇ )(OR ₃₈ ); R ₃₆ ～ R ₃₈ each independently represent a hydrogen atom or A monovalent organic group; R ₃₇ and R ₃₈ may be bonded to each other to form a ring; n-represents an integer of 1 to 4. <9> The resist composition according to <8>, wherein the repeating unit (c) is a repeating unit represented by the above formula (AII), and Y ₂ in the formula (AII) At least one of the groups desorbed by the action of an acid is a structure represented by the following formula (Y3-1);

[化8]

L ₁₀ represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group, L ₂₀ represents a tertiary alkyl group; M represents a single bond or a divalent linking group; and Q represents an alkyl group, a cycloalkyl group which may contain a hetero atom, An aryl group, an amine group, an ammonium group, a thiol group, a cyano group or an aldehyde group which may contain a hetero atom. <10> The resist composition according to <8>, wherein the repeating unit (c) is a repeating unit represented by the above formula (AII), and at least Y ₂ in the formula (AII) The group which is detached by the action of an acid is a structure represented by the following general formula (Y3-2);

[Chemistry 9]

L ₁₀ represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group, L ₂₁ represents a secondary alkyl group; M represents a single bond or a divalent linking group; and Q represents an alkyl group, a cycloalkyl group which may contain a hetero atom, An aryl group, an amine group, an ammonium group, a thiol group, a cyano group or an aldehyde group which may contain a hetero atom. <11> The resist composition according to <7>, wherein the repeating unit (c) is a repeating unit represented by the following formula (AI-2);

[化10]

In the formula (AI-2), Xa ₁ represents a hydrogen atom or an alkyl group; T represents a single bond or a divalent linking group; and Y is a group which is desorbed by the action of an acid, and represents a formula (Y1) of the following formula: a group represented by the formula (Y2) or the formula (Y4); a formula (Y1): -C(Rx ₁ )(Rx ₂ )(Rx ₃ ), a formula (Y2): -C(=O)O (Rx ₁ )(Rx ₂ )(Rx ₃ ) Formula (Y4): -C(Rn)(H)(Ar) In the formula (Y1) and the formula (Y2), Rx ₁ to Rx ₃ are independently In the formula (Y4), Ar represents an aromatic ring group; Rn represents an alkyl group, a cycloalkyl group or an aryl group; and Rn and Ar may be bonded to each other to form a non-aromatic ring. <12> The resist composition according to <7>, wherein the repeating unit (c) is a repeating unit represented by the following formula (AII-2);

[11]

In the formula (AII-2), R ₆₁ , R ₆₂ and R ₆₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group; wherein R ₆₂ may be bonded to Ar ₆ bonded to form a ring, R ₆₂ in this case represents a single bond or alkylene; _X-6 represents a single bond, -COO-, or -CONR ₆₄ -; R ₆₄ represents a hydrogen atom or an alkyl group; L represents a single ₆ a bond or an alkyl group; Ar ₆ represents an (n+1)-valent aromatic ring group, and in the case of bonding to R ₆₂ to form a ring, represents an (n+2)-valent aromatic ring group; n represents 1 to 4 integer; in the case of n ≧ 2, Y ₂ each independently represent a hydrogen atom or disengaged by the action of an acid group; wherein, Y ₂ represents at least one disengaged by the action of an acid group, represented by the following a group represented by the formula (Y1), (Y2) or (Y4); a formula (Y1): -C(Rx ₁ )(Rx ₂ )(Rx ₃ ), a formula (Y2): -C(=O) O(Rx ₁ )(Rx ₂ )(Rx ₃ ) General formula (Y4): -C(Rn)(H)(Ar) In the general formula (Y1) and the general formula (Y2), Rx ₁ to Rx ₃ respectively Independently represents an alkyl group or a cycloalkyl group; in the formula (Y4), Ar represents an aromatic ring group; and Rn represents an alkyl group, a cycloalkyl group or an aromatic group. ; And Rn of Ar may be bonded to each other to form a non-aromatic ring. The resist composition according to any one of <1> to <12> wherein the resin (P) further contains a group selected from a fluorine atom, a group having a fluorine atom, and a germanium atom. One or more groups selected from the group consisting of an alkyl group having 6 or more carbon atoms, a cycloalkyl group having 5 or more carbon atoms, an aryl group having 6 or more carbon atoms, and an aralkyl group having 7 or more carbon atoms Repeat unit. The resist composition according to any one of <1> to <13> further comprising a compound which generates an acid by irradiation with actinic rays or radiation. <15> A resist film which is formed from the resist composition according to any one of <1> to <14>. <16> A blank mask having the resist film as described in <15>. <17> A pattern forming method, comprising: (a) a step of forming a resist film from the resist composition according to any one of <1> to <14>, (c) by actinicizing a step of exposing the resist film by radiation or radiation, and (d) a step of developing the exposed resist film with a developing solution. <18> The pattern forming method according to <17>, wherein the actinic ray or radiation is an electron beam or an extreme ultraviolet ray. <19> The pattern forming method according to <18>, wherein the developing solution is developed using a developing solution containing an organic solvent to form a negative pattern. <20> The pattern forming method according to <17>, wherein the developing solution is developed by using an alkaline developing solution to form a positive pattern. <21> A method of forming an electronic component, comprising the pattern forming method according to any one of <17> to <20>. [Effects of the Invention]

According to the present invention, there can be provided a resist composition, a resist film using the resist composition, a blank mask, a pattern forming method, and a method of manufacturing an electronic component, the resist composition being particularly When a pattern of ultrafine (for example, a line width of 50 nm) is formed, a pattern excellent in resolution and LWR performance can be formed, and the number of particles is small.

Hereinafter, embodiments for carrying out the invention will be described. In addition, in the expression of the group (atomic group) in the present specification, the unsubstituted and unsubstituted expressions include not only a group having no substituent (atomic group) but also a group having a substituent (atomic group). 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). The "actinic ray" or "radiation" in the present specification means, for example, a bright line spectrum of a mercury lamp, a far ultraviolet ray represented by an excimer laser, an extreme ultraviolet ray (EUV light), an X-ray, an electron beam, or the like. In the present invention, the term "light" means actinic rays or radiation. The "exposure" in the present specification includes not only mercury lamps, far ultraviolet rays typified by excimer lasers, X-rays, EUV light, etc., but also particles such as electron beams and ion beams. The depiction of the bundle is also included in the exposure. In the present specification, the term "(meth)acrylic monomer" means at least one of monomers having a structure of "CH ₂ =CH-CO-" or "CH ₂ =C(CH ₃ )-CO-". Similarly, “(meth)acrylate” and “(meth)acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”. In the present specification, when the molecular weight has a distribution, it is represented by a weight average molecular weight. In the present specification, the weight average molecular weight of the resin is a polystyrene equivalent value measured by a gel permeation chromatography (GPC) method. GPC can be used as follows: HLC-8120 (manufactured by Tosoh (TOSOH) Co., Ltd.) and TSK gel Multipore HXL-M (manufactured by Tosoh (TOSOH), 7.8 mmID × 30.0 cm) Tetrahydrofuran (THF) was used as the eluent.

[Resist Composition] The resist composition of the present invention is a resist composition containing a resin (P) containing a repeating unit (a) having an intramolecular salt structure. The resist composition of the present invention is preferably a chemically amplified resist composition. The resist composition of the present invention is preferably a resist composition for developing an organic solvent using a developing solution containing an organic solvent and/or an alkali developing solution using an alkaline developing solution. Here, the term "organic solvent development" means use for at least a step of performing development using a developer containing an organic solvent. The term "alkali development" refers to the use of at least a step of performing development using an alkaline developer. The resist composition of the present invention may be a positive resist composition or a negative resist composition. The resist composition of the present invention is preferably used for electron beam or extreme ultraviolet exposure.

<Resin (P) containing repeating unit (a) having an intramolecular salt structure> Resin (P) containing a repeating unit (a) having an intramolecular salt structure (hereinafter, also simply referred to as "resin (P)") Be explained.

(Repeating unit (a) having an intramolecular salt structure) The resin (P) contains a repeating unit (a) having an intramolecular salt structure (hereinafter, also simply referred to as "repeating unit (a)"). In the present invention, the "intramolecular salt structure" means a structure in which at least one cation and at least one anion are linked by a covalent bond in the same molecule. The intramolecular salt structure is preferably any one of the structures represented by the following general formula (U-1), general formula (U-2), or general formula (U-3).

[化12]

In the general formula (U-1), the general formula (U-2), and the general formula (U-3), E ₁ and E ₂ represent a structure having a cation, and G ₁ and G ₂ represent a structure having an anion, and L ⁰ represents Single bond or link base. * indicates a linking site to the polymer main chain or side chain of the resin (P).

E ₁ and E ₂ represent a structure having a cation, and preferably a structure having a cation such as ammonium, ruthenium, osmium or iridium. E _{1 is,} for example, the following group, but is not limited thereto.

[Chemistry 13]

In the above structural formula, R ₃₁ to R ₃₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and R ₃₁ and R ₃₂ may be bonded to each other to form a ring structure. * indicates a linking site to the polymer main chain or side chain of the resin (P).

E _{2 is,} for example, the following group, but is not limited thereto.

[Chemistry 14]

In the above structural formula, R ₄₁ to R ₄₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and R ₄₁ and R ₄₂ may be bonded to each other to form a ring structure. * indicates a linking site to the polymer main chain or side chain of the resin (P).

G ₁ and G _{2 each} have a structure having an anion, and preferably a structure having an anion such as a carboxylate, a sulfonate, a phosphonate or a phosphinate.

G _{1 is,} for example, the following group, but is not limited thereto. * indicates a linking site to the polymer main chain or side chain of the resin (P).

[化15]

G _{2 is,} for example, the following group, but is not limited thereto. * indicates a linking site to the polymer main chain or side chain of the resin (P).

[Chemistry 16]

L ⁰ represents a single bond or a linking group, and when it represents a linking group, it is preferably selected from -CO-, -O-, -NH-, a divalent aliphatic group, a divalent aromatic group, and the like. The linkages in the group consisting of the combinations. Examples of the divalent aliphatic group include an alkylene group (preferably having a carbon number of 1 to 20, more preferably a carbon number of 1 to 10), and examples of the divalent aromatic group include a stretching phenyl group and a xylyl group. The aryl group is preferably an aryl group (preferably having a carbon number of 6 to 15, more preferably 6 to 10).

Specific examples of L ⁰ include the following linking groups, but are not limited thereto.

[化17]

Further, the linking groups may further have a substituent. Examples of the substituent include a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, an amine group, a cyano group, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a decyl group, and an alkoxy group. A carbonyl group, an aryloxycarbonyl group, a decyloxy group, a monoalkylamino group, a dialkylamino group, a monoarylamino group, a diarylamino group or the like.

When L ⁰ represents a linking group, it is preferably 30 or less carbon atoms (in the case of having a substituent, the carbon number of the substituent is also 30 or less).

The resin (P) preferably has an intramolecular salt structure at a side chain portion of the polymer in the repeating unit (a) having an intramolecular salt structure. The repeating unit (a) is preferably represented by the following formula (i) or formula (ii).

[化18]

In the general formula (i) and the general formula (ii), Y ₁ , Y ₂ , R ₁₀₁ , R ₁₀₂ , R ₁₀₃ and R ₁₀₄ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, a nitro group or an organic group. . L ₁ to L ₄ , Z ₁ and Z ₂ each independently represent a single bond or a divalent linking group. E ₁ and E ₂ represent a structure having a cation, and G ₁ and G ₂ represent a structure having an anion.

Y ₁ and Y ₂ represents a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, a nitro group or an organic group, preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a halogen atom, more preferably a hydrogen atom or a methyl group . R ₁₀₁ , R ₁₀₂ , R ₁₀₃ and R ₁₀₄ represent a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, a nitro group or an organic group, preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom, more preferably It is a hydrogen atom or a methyl group, and is preferably a hydrogen atom.

L ₁ and L ₃ represent a single bond or a divalent linking group, and as a divalent linking group, it is preferably selected from -CO-, -O-, -NH-, a divalent aliphatic group, and a divalent aromatic group. A linking group in a group consisting of a group and a combination of these. The divalent aliphatic group may, for example, be an alkyl group, an alkenyl group, an alkynyl group or a polyalkylene group. Among them, an alkyl group and an alkenyl group are preferred, and an alkyl group is preferred. Regarding the divalent aliphatic group, the aliphatic group of the chain structure is superior to the aliphatic group of the cyclic structure, and thus the aliphatic group having a linear structure is superior to the chain structure having a branch. The carbon number of the divalent aliphatic group (including the carbon number of the substituent in the case of having a substituent) is preferably from 1 to 20, more preferably from 1 to 15, still more preferably from 1 to 12, and still more preferably 1 to 10, preferably 1 to 8. The divalent aliphatic group may have a substituent, and examples of the substituent include a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, an amine group, a cyano group, an aryl group, an alkoxy group, and an aryl group. Oxyl, decyl, alkoxycarbonyl, aryloxycarbonyl, decyloxy, monoalkylamino, dialkylamino, arylamino and diarylamine groups.

The divalent aromatic group is preferably an aryl group, more preferably a phenyl group or a naphthyl group. The divalent aromatic group may have a substituent, and examples of the substituent include an alkyl group in addition to the substituent of the divalent aliphatic group.

L ₁ and L _{3 are} preferably a single bond or are selected from -CO-, -O-, -COO-, -NH-, -CONH-, a divalent aliphatic group, a divalent aromatic group, and The linking group in the group consisting of these combinations is more preferably a single bond, -O-, -COO-, or -CONH-.

Z ₁ and Z ₂ represent a single bond or a divalent linking group, and are the same as the above-mentioned L ₁ and L ₃ as a divalent linking group. Z ₁ and Z _{2 are} preferably a single bond or selected from -CO-, -O-, -COO-, -NH-, -CONH-, a divalent aliphatic group, a divalent aromatic group, and The linking group in the group consisting of these combinations is more preferably a single bond, a divalent aliphatic group, or a divalent aromatic group.

E ₁ , E ₂ , G ₁ and G _{2 are the same} as those described in the above formula (U-1), formula (U-2) and formula (U-3). L ₂ and L ₄ are the same as those described for L ⁰ in the above formula (U-1), formula (U-2), and formula (U-3).

The repeating unit (a) is preferably represented by the following formula (i-1), formula (i-2), formula (i-3) or formula (ii-1).

[Chemistry 19]

In the general formula (i-1), the general formula (i-2), the general formula (i-3), and the general formula (ii-1), Y ₁ , Y ₂ , R ₁₀₁ , R ₁₀₂ , R ₁₀₃ and R ₁₀₄ Each independently represents a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, a nitro group or an organic group. L ₁ to L ₄ , Z ₁ and Z ₂ each independently represent a single bond or a divalent linking group. E ₁ represents a structure having a cation, and G ₁ represents a structure having an anion. R ₄₁ to R ₄₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and R ₄₁ and R ₄₂ may be bonded to each other to form a ring structure. R ₅₀ represents a substituent, and k represents an integer of 0 to 4. When k represents an integer of 2 or more, R ₅₀ may be the same or different.

In the general formula (i-1), the general formula (i-2), the general formula (i-3), and the general formula (ii-1), Y ₁ , Y ₂ , R ₁₀₁ , R ₁₀₂ , R ₁₀₃ , R ₁₀₄ , L ₁ to L ₄ , Z ₁ , Z ₂ , E ₁ and G ₁ are respectively Y ₁ , Y ₂ , R ₁₀₁ , R ₁₀₂ , R ₁₀₃ , R _{104 in the} formula (i) and the formula (ii) L ₁ to L ₄ , Z ₁ , Z ₂ , E ₁ and G _{1 are the} same.

In the general formulae (i-1) to (i-3), R ₄₁ to R ₄₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and R ₄₁ and R ₄₂ may be joined to each other to form a ring structure. The ring structure may have a hetero atom such as an oxygen atom, preferably a 5-membered ring to a 10-membered ring, more preferably a 5-membered ring or a 6-membered ring. The carbon number of R ₄₁ to R _{43 (} the carbon number of the substituent in the case of having a substituent) is preferably from 1 to 30, more preferably from 1 to 20, particularly preferably from 1 to 15 carbon atoms. The best carbon number is 1-8.

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an octyl group, an isopropyl group, a tert-butyl group, an isopentyl group, a 2-ethylhexyl group, a 2-methylhexyl group, a cyclopentyl group and the like. Examples of the alkenyl group include a vinyl group, an allyl group, a prenyl group, a geranyl group, and an oleyl group. Examples of the alkynyl group include an ethynyl group, a propargyl group, a trimethyldecyl ethynyl group and the like. Further, examples of the aryl group include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group. Further, examples of the heterocyclic group include a furyl group, a thienyl group, a pyridyl group and the like.

These groups may further have a substituent. Examples of the substituent include a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, an amine group, a cyano group, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a decyl group, and an alkoxy group. A carbonyl group, an aryloxycarbonyl group, a decyloxy group, a monoalkylamino group, a dialkylamino group, a monoarylamino group, a diarylamino group or the like.

Examples of R ₄₁ to R ₄₃ include a hydrogen atom, a methyl group, or an ethyl group from the viewpoint of the effect and ease of availability.

R ₅₀ in the formula (i-2) represents a substituent, and examples of the substituent include a halogen atom, an alkyl group, a cycloalkyl group (including a bicycloalkyl group), an alkenyl group, and a cycloalkenyl group (including a bicycloalkenyl group). Alkynyl, aryl, heterocyclyl, cyano, hydroxy, nitro, carboxy, alkoxy, aryloxy, decyloxy, heterocyclooxy, decyloxy, amine methionyloxy , alkoxycarbonyloxy, aryloxycarbonyloxy, amine (including anilino), mercaptoamine, aminocarbonylamino, alkoxycarbonylamino, aryloxycarbonylamino, Aminesulfonylamino, alkylsulfonylamino and arylsulfonylamino, fluorenyl, alkylthio, arylthio, heterocyclic thio, sulfonyl, sulfo, alkyl sulfin Sulfhydryl and arylsulfinyl, alkylsulfonyl and arylsulfonyl, fluorenyl, aryloxycarbonyl, alkoxycarbonyl, aminemethanyl, arylazo and heterocyclic A nitrogen group, a quinone imine group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, a decyl group is exemplified.

k represents an integer of 0 to 4, preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0.

From the viewpoint of the analytical property and the LWR performance, the ratio of the repeating unit (a) having an intramolecular salt structure in the resin (P) is preferably 0.5 mol% with respect to all the repeating units constituting the resin (P). The range of 99% by mole, more preferably in the range of 0.5% by mole to 70% by mole, particularly preferably in the range of 1% by mole to 50% by mole, most preferably from 1% by mole to 30% by mole. range.

Specific examples of the repeating unit (a) having an intramolecular salt structure are shown below, but the present invention is not limited thereto. Ph represents a phenyl group.

[Chemistry 20]

[Chem. 21]

[化22]

[化23]

[Chem. 24]

The resin (P) can be synthesized in accordance with a conventional method such as radical polymerization. For example, as a general synthesis method, a batch polymerization method in which a monomer species and an initiator are dissolved in a solvent and then heated to carry out polymerization is used, and the monomer species and the initiator are used for 1 hour to 10 hours. The dropwise addition of the solution to the heating solvent, etc., is preferably a dropwise addition polymerization method. Examples of the solvent include ether solvents such as tetrahydrofuran, 1,4-dioxane and diisopropyl ether; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; and ester solvents such as ethyl acetate; A guanamine solvent such as carbamide or dimethylacetamide; a solvent such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether or cyclohexanone to be dissolved, and the like. More preferably, it is preferred to carry out polymerization by using the same solvent as that used in the resist composition. Thereby, generation of particles during storage can be suppressed.

The polymerization reaction is preferably carried out under an inert gas atmosphere such as nitrogen or argon. It is preferred to use a commercially available radical initiator (azo initiator, peroxide, etc.) as a polymerization initiator to start the polymerization. The radical initiator is preferably an azo initiator, and is preferably an azo initiator having an ester group, a cyano group or a carboxyl group. Preferred examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2'-azobis(2-methylpropionate), and the like. The initiator may be added in an additional step or in a stepwise manner, and after the reaction is completed, it may be introduced into a solvent and the desired polymer may be recovered by a method such as powder recovery or solid recovery. The concentration of the reaction is preferably from 5% by mass to 50% by mass, more preferably from 10% by mass to 45% by mass. The reaction temperature is usually preferably from 10 ° C to 150 ° C, more preferably from 30 ° C to 120 ° C, still more preferably from 60 ° C to 100 ° C. For the purification, a general method such as the following method: a liquid-liquid extraction method in which residual monomers or oligomer components are removed by washing with water or a suitable solvent; and purification in a solution state such as ultrafiltration which is extracted and removed only by a specific molecular weight or less can be applied. Or a reprecipitation method in which a resin is coagulated in a poor solvent by a resin solution in a poor solvent, thereby removing residual monomers or the like; or cleaning the filtered resin slurry by using a poor solvent A purification method or the like in a solid state.

The weight average molecular weight of the resin (P) is preferably from 1,000 to 200,000, more preferably from 3,000 to 20,000, most preferably from 5,000 to 15,000, in terms of polystyrene equivalent value by the GPC method. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance or dry etching resistance can be prevented, and deterioration of developability and viscosity can be prevented, and film formability can be deteriorated. The degree of dispersion (molecular weight distribution) is usually from 1 to 5, and a resin having a degree of dispersion (molecular weight distribution) of preferably from 1 to 3, more preferably from 1.2 to 3.0, particularly preferably from 1.2 to 2.0 is used. The more the resin having a small dispersion, the more excellent the resolution and the resist shape, and the smoother the side wall of the resist pattern, the more excellent the roughness.

(Repeating unit (b) having an aromatic ring group) The resin (P) may further comprise a repeating unit (b) having an aromatic ring group. The repeating unit (b) having an aromatic ring group is preferably a repeating unit represented by the following formula (A).

[化25]

In the above formula (A), R ₁₁ , R ₁₂ and R ₁₃ each independently represent a hydrogen atom, an alkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. Wherein R ₁₂ may be bonded to L to form a ring, and in this case, R ₁₂ represents a single bond or an alkylene group. X represents a single bond, -COO-, or -CONR ₃₀ -, and R ₃₀ represents a hydrogen atom or an alkyl group. L represents a single bond or an alkyl group. Z represents a hydrogen atom or an (m+1)-valent aromatic ring group, and when it is bonded to R ₁₂ to form a ring, it represents an (m+2)-valent aromatic ring group. Further, Z may have a hydroxyl group as a substituent. m represents an integer of 1 to 5.

R ₁₁ , R ₁₂ , R ₁₃ , X, L, and Z in the above formula (A) are respectively R ₄₁ , R ₄₂ , R ₄₃ , X ₄ , L ₄ , and Ar in the above-described general formula (I). _{4 is the} same.

As the repeating unit (b) having an aromatic ring group, a repeating unit having a phenolic hydroxyl group is preferably exemplified. In the present specification, the phenolic hydroxyl group means a group in which a hydrogen atom of an aromatic ring group is substituted with a hydroxyl group. The aromatic ring of the aromatic ring group may be a monocyclic or polycyclic aromatic ring, and examples thereof include a benzene ring or a naphthalene ring.

The repeating unit having a phenolic hydroxyl group may, for example, be a repeating unit represented by the following formula (I) or formula (I-1).

[Chem. 26]

In the formula, R ₄₁ , R ₄₂ and R ₄₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. Wherein R ₄₂ may be bonded to Ar ₄ to form a ring, and in this case, R ₄₂ represents a single bond or an alkylene group. X ₄ represents a single bond, -COO-, or -CONR ₆₄ -, and R ₆₄ represents a hydrogen atom or an alkyl group. L ₄ each independently represents a single bond or a divalent linking group. Ar ₄ represents an (n+1)-valent aromatic ring group, and when it is bonded to R ₄₂ to form a ring, it represents an (n+2)-valent aromatic ring group. n represents an integer of 1 to 5. For the purpose of increasing the polarity of the repeating unit of the formula (I) or the formula (I-1), n is preferably an integer of 2 or more, or X ₄ is -COO- or -CONR ₆₄ -.

The alkyl group of R ₄₁ , R ₄₂ and R ₄₃ in the formula (I) and the formula (I-1) is preferably a methyl group, an ethyl group, a propyl group or an isopropyl group which may have a substituent. An alkyl group having a carbon number of 20 or less, such as n-butyl group, t-butyl group, hexyl group, 2-ethylhexyl group, octyl group or dodecyl group, more preferably an alkyl group having 8 or less carbon atoms, particularly preferably An alkyl group having 3 or less carbon atoms is listed.

The cycloalkyl group of R ₄₁ , R ₄₂ and R ₄₃ in the formula (I) and the formula (I-1) may be a monocyclic type or a polycyclic type. The monocyclo type cycloalkyl group having 3 to 8 carbon atoms such as a cyclopropyl group, a cyclopentyl group or a cyclohexyl group which may have a substituent is preferable. The halogen atom of R ₄₁ , R ₄₂ and R ₄₃ in the general formula (I) and the general formula (I-1) may, for example, be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and particularly preferably a fluorine atom. The alkyl group contained in the alkoxycarbonyl group of R ₄₁ , R ₄₂ and R ₄₃ in the formula (I) and the formula (I-1) is preferably the same as the above R ₄₁ , R ₄₂ and R _{43 .} The alkyl group in the same.

Preferred examples of the substituent in the respective groups include an alkyl group, a cycloalkyl group, an aryl group, an amine group, a decylamino group, a ureido group, a urethane group, a hydroxyl group, a carboxyl group, and a halogen atom. The alkoxy group, the thioether group, the decyl group, the decyloxy group, the alkoxycarbonyl group, the cyano group, the nitro group or the like has a carbon number of the substituent of preferably 8 or less.

Ar ₄ represents an (n+1)-valent aromatic ring group. When the n is 1, the divalent aromatic ring group may have a substituent, and examples thereof include a phenyl group having 6 to 18 carbon atoms such as a phenylene group, a methylphenyl group, an anthranyl group, and a fluorenyl group, or a thiophene group. Preferred are aromatic ring groups containing a heterocyclic ring such as furan, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole or thiazole.

Specific examples of the (n+1)-valent aromatic ring group when n is an integer of 2 or more are preferably exemplified by (n-1) arbitrary hydrogens removed from the specific example of the divalent aromatic ring group. The base of the atom. The (n+1)-valent aromatic ring group may further have a substituent.

Examples of the substituent which the alkyl group, the cycloalkyl group, the alkoxycarbonyl group and the (n+1)-valent aromatic ring group may have include, for example, R ₄₁ , R ₄₂ and R ₄₃ in the formula (I). The alkoxy group such as an alkyl group, a methoxy group, an ethoxy group, a hydroxyethoxy group, a propoxy group, a hydroxypropoxy group or a butoxy group; an aryl group such as a phenyl group or the like. The alkyl group of R ₆₄ in -CONR ₆₄ - (R ₆₄ represents a hydrogen atom or an alkyl group) represented by X ₄ is preferably a methyl group, an ethyl group, a propyl group or an isopropyl group which may have a substituent. The alkyl group having a carbon number of 20 or less, such as a group, n-butyl group, a second butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group or a dodecyl group, more preferably an alkyl group having 8 or less carbon atoms. As X ₄ , a single bond, -COO-, -CONH- is preferred, and a single bond or -COO- is more preferred.

The divalent linking group of L ₄ is preferably an alkylene group, and examples of the alkylene group include a methylene group which may have a substituent, an exoethyl group, a propyl group, a butyl group, and a hexyl group. An alkyl group having 1 to 8 carbon atoms, such as octyl. Further, Ar _{4 is more} preferably an aromatic ring group having 6 to 18 carbon atoms which may have a substituent, and particularly preferably a benzene ring group, a naphthalene ring group or a stretched biphenyl ring group. The repeating unit represented by the formula (I) preferably has a hydroxystyrene structure. That is, Ar _{4 is} preferably a benzene ring group.

The repeating unit having a phenolic hydroxyl group is preferably a repeating unit represented by the following formula (p1).

[化27]

R in the formula (p1) represents a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of Rs may be the same or different. As R in the formula (p1), a hydrogen atom is particularly preferred.

In the general formula (p1), Ar represents an aromatic ring, and examples thereof include an aromatic hydrocarbon ring having a carbon number of 6 to 18, such as a benzene ring, a naphthalene ring, an anthracene ring, an anthracene ring, and a phenanthrene ring; or Thiophene ring, furan ring, pyrrole ring, benzothiophene ring, benzofuran ring, benzopyrrole ring, triazine ring, imidazole ring, benzimidazole ring, triazole ring, thiadiazole ring, thiazole ring, etc. Ring aromatic ring heterocycle. Among them, the best is a benzene ring.

m in the formula (p1) represents an integer of 1 to 5, preferably 1.

Specific examples of the repeating unit having a phenolic hydroxyl group are shown below, but the present invention is not limited thereto. Where a represents 1 or 2. In addition, as a specific example of the repeating unit having a phenolic hydroxyl group, a specific example described in [0177] to [0178] of JP-A-2014-232309 can be incorporated into the specification of the present application. .

[化28]

[化29]

In the case where the resin (P) contains a repeating unit having a phenolic hydroxyl group, it may contain a repeating unit having a phenolic hydroxyl group, or may contain two or more repeating units having a phenolic hydroxyl group.

In the case where the resin (P) contains a repeating unit having a phenolic hydroxyl group, the content of the repeating unit having a phenolic hydroxyl group is preferably from 10 mol% to 95 mol%, based on all the repeating units of the resin (P). More preferably, it is 20 mol% to 90 mol%, and further preferably 30 mol% to 85 mol%.

The repeating unit (b) having an aromatic ring group may be a repeating unit represented by the following formula (X).

[化30]

In the formula (X), R ₆₁ , R ₆₂ and R ₆₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. Wherein R ₆₃ may be bonded to Ar to form a ring, and in this case, R ₆₃ represents a single bond or an alkylene group. Ar represents an (n+1)-valent aromatic ring group, and when it is bonded to R ₆₃ to form a ring, it represents an (n+2)-valent aromatic ring group. R ₇ each independently represent a carbon number of 1 to 10 linear, branched or cyclic alkyl, alkoxy or acyl group, a cyano group, a nitro group, an amine group, a halogen atom, an ester group (-OCOR Or -COOR: R is an alkyl group having 1 to 6 carbon atoms or a fluorinated alkyl group) or a carboxyl group. n represents an integer of 0 or more.

The formula (X) is also preferably a repeating unit represented by the following formula (V) or the following formula (VI).

[化31]

In the formula, n3 represents an integer of 0-4. N4 represents an integer of 0-6. X ₄ is a methylene group, an oxygen atom or a sulfur atom. R ₇ in the general formula (X) are the same meaning as R _7.

Specific examples of the repeating unit represented by the general formula (X) are shown below, but are not limited thereto.

[化32]

[化33]

When the resin (P) contains a repeating unit represented by the formula (X), it may comprise a repeating unit represented by the formula (X), or may contain two or more repeats represented by the formula (X). unit.

In the case where the resin (P) contains a repeating unit represented by the formula (X), the content of the repeating unit represented by the formula (X) is preferably 5 mol% with respect to all the repeating units of the resin (P). ～50 mol%, more preferably 5 mol% to 40 mol%, and further preferably 5 mol% to 30 mol%.

Further, the repeating unit (b) having an aromatic ring group may be an aromatic ring group in the repeating unit (c) having a structure protected by a leaving group which is decomposed and desorbed by the action of a polar group via acid.

In the case where the resin (P) contains a repeating unit (b) having an aromatic ring group, it may contain a repeating unit (b) having an aromatic ring group, and may further contain two or more repeating units having an aromatic ring group (b) ).

In the case where the resin (P) contains the repeating unit (b) having an aromatic ring group, the content of the repeating unit (b) having an aromatic ring group is preferably 5 mol% with respect to all the repeating units of the resin (P). ～100 mol%, more preferably 7 mol% to 98 mol%, and further preferably 8 mol% to 96 mol%.

(Repeating unit (c) having a structure in which a polar group is decomposed and desorbed by the action of an acid) The resin (P) in a preferred embodiment contains a polar group by decomposition of an acid and The detached unit (c) of the structure of the detached base-protected structure. Examples of the polar group in the repeating unit (c) of the structure (acid-decomposable group) which is decomposed and desorbed by the action of a polar group by acid action include a carboxyl group, an alcoholic hydroxyl group, a phenolic hydroxyl group, and a sulfonate. Acid group and the like. Among these, the polar group is preferably a carboxyl group, an alcoholic hydroxyl group, or a phenolic hydroxyl group, and further preferably a carboxyl group or a phenolic hydroxyl group. In addition, when the resin (P) contains a repeating unit having an acid-decomposable group, the solubility in the alkaline developing solution increases due to the action of the acid, and the solubility in the organic solvent decreases.

Examples of the leaving group which is decomposed and desorbed by the action of an acid include a group represented by the following general formula (Y1) to (Y4). General formula (Y1): -C(Rx ₁ )(Rx ₂ )(Rx ₃ ) Formula (Y2): -C(=O)O(Rx ₁ )(Rx ₂ )(Rx ₃ ) Formula (Y3) :-C(R ₃₆ )(R ₃₇ )(OR ₃₈ ) General formula (Y4): -C(Rn)(H)(Ar)

In the general formula (Y1) and the general formula (Y2), Rx ₁ to Rx ₃ each independently represent an alkyl group (straight chain or branched) or a cycloalkyl group (monocyclic or polycyclic). In the case where all of Rx ₁ to Rx ₃ are an alkyl group (straight chain or branched), at least two of Rx ₁ to Rx ₃ are preferably a methyl group. More preferably Rx ₁ ~ Rx ₃ each independently represent a repeating unit of a linear or branched alkyl group, and thus is good Rx ₁ ~ Rx ₃ each independently represent a linear alkyl group of repeating units. Two of Rx ₁ to Rx ₃ may be bonded to form a single ring or multiple rings. The alkyl group of Rx ₁ to Rx ₃ is preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a t-butyl group. The cycloalkyl group of Rx ₁ to Rx ₃ is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, a norbornyl group, a tetracyclodecyl group, a tetracyclododecyl group or an adamantyl group. Ring cycloalkyl. The cycloalkyl group formed by the two bonds of Rx ₁ to Rx ₃ is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, a norbornyl group, a tetracyclodecyl group or a tetracyclododecane. a polycyclic cycloalkyl group such as a benzyl group or an adamantyl group. Particularly preferred is a monocyclic cycloalkyl group having 5 to 6 carbon atoms. The cycloalkyl group formed by the two bonds of Rx ₁ to Rx ₃ , for example, one of the methylene groups constituting the ring may be substituted with a hetero atom such as an oxygen atom or a group having a hetero atom such as a carbonyl group. The repeating unit represented by the formula (Y1) or the formula (Y2) is preferably a form in which Rx ₁ is a methyl group or an ethyl group and Rx ₂ and Rx _{3 are} bonded to each other to form the cycloalkyl group.

In the formula (Y3), R ₃₆ to R ₃₈ each independently represent a hydrogen atom or a monovalent organic group. R ₃₇ and R ₃₈ may be bonded to each other to form a ring. The monovalent organic group may, for example, be an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group. R _{36 is} also preferably a hydrogen atom.

The formula (Y3) is more preferably a structure represented by the following formula (Y3-1).

[化34]

Here, L ₁ and L ₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group in which an alkyl group and an aryl group are combined. M represents a single bond or a divalent linking group. Q represents an alkyl group, a cycloalkyl group which may contain a hetero atom, an aryl group which may contain a hetero atom, an amine group, an ammonium group, a fluorenyl group, a cyano group or an aldehyde group. At least one of L ₁ and L ₂ is a hydrogen atom, and preferably at least one is an alkyl group, a cycloalkyl group, an aryl group, or a group in which an alkyl group and an aryl group are combined. At least two of Q, M, and L ₁ may be bonded to form a ring (preferably a 5-membered ring or a 6-membered ring). In terms of improvement in pattern collapse property, L _{2 is} preferably a secondary or tertiary alkyl group, more preferably a tertiary alkyl group. The secondary alkyl group may, for example, be an isopropyl group, a cyclohexyl group or a norbornyl group, and the tertiary alkyl group may be a tertiary butyl group or adamantane. In these forms, since Tg or activation energy becomes high, in addition to ensuring film strength, blurring can be suppressed.

In the formula (Y4), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group or an aryl group. Rn and Ar may be bonded to each other to form a non-aromatic ring. Ar is more preferably an aryl group.

The repeating unit having a group which decomposes due to the action of an acid and generates a polar group is preferably a repeating unit represented by the following formula (AI) or formula (AII).

[化35]

In the general formula (AI), Xa ₁ represents a hydrogen atom or an alkyl group. T represents a single bond or a divalent linking group. Y represents a group which is detached by the action of an acid. Y is preferably any one of the above formula (Y1) to formula (Y4).

The alkyl group represented by Xa ₁ may be an alkyl group having a substituent, and examples thereof include a methyl group or a group represented by -CH ₂ -R ₁₁ . R ₁₁ represents a halogen atom (such as a fluorine atom), a hydroxyl group or a monovalent organic group, and examples thereof include an alkyl group having 5 or less carbon atoms and a fluorenyl group having 5 or less carbon atoms, preferably an alkyl group having 3 or less carbon atoms. Good for methyl. Xa ₁ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group in one form. Examples of the divalent linking group of T include an alkylene group, an extended aryl group, a —COO—Rt— group, and an —O—Rt— group. In the formula, Rt represents an alkylene group or a cycloalkyl group. T is preferably a single bond or a -COO-Rt- group. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a -CH ₂ - group, a -(CH ₂ ) ₂ - group or a -(CH ₂ ) ₃ - group.

In the formula (AII), R ₆₁ , R ₆₂ and R ₆₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. Wherein R ₆₂ may be bonded to Ar ₆ to form a ring, and in this case, R ₆₂ represents a single bond or an alkylene group. X ₆ represents a single bond, -COO-, or -CONR ₆₄ -. R ₆₄ represents a hydrogen atom or an alkyl group. L ₆ represents a single bond or an alkyl group. Ar ₆ represents an (n+1)-valent aromatic ring group, and when it is bonded to R ₆₂ to form a ring, it represents an (n+2)-valent aromatic ring group. In the case of n ≧ 2, Y ₂ independently represents a hydrogen atom or a group which is detached by the action of an acid. Here, at least one of Y ₂ represents a group which is detached by the action of an acid. The group which is desorbed by the action of an acid of Y ₂ is preferably any of the above formula (Y1) to formula (Y4). n represents an integer of 1 to 4.

Each of the groups may have a substituent. Examples of the substituent include an alkyl group (having a carbon number of 1 to 4), a halogen atom, a hydroxyl group, an alkoxy group (having a carbon number of 1 to 4), a carboxyl group, and an alkoxycarbonyl group (carbon). The number is 2 to 6), etc., preferably 8 or less.

The repeating unit represented by the formula (AI) is preferably an acid-degradable tertiary alkyl (meth)acrylate-based repeating unit (Xa ₁ represents a hydrogen atom or a methyl group and T represents a repeating unit of a single bond).

The repeating unit represented by the above formula (AII) is preferably a repeating unit represented by the following formula (AIII).

[化36]

In the formula (AIII), Ar ₃ represents an aromatic ring group. In the case of n ≧ 2, Y ₂ independently represents a hydrogen atom or a group which is detached by the action of an acid. Here, at least one of Y ₂ represents a group which is detached by the action of an acid. The group which is desorbed by the action of an acid of Y ₂ is preferably any of the above formula (Y1) to formula (Y4). n represents an integer of 1 to 4.

The aromatic ring group represented by Ar ₆ and Ar ₃ is preferably a benzene ring group or a naphthalene ring group, and more preferably a benzene ring group.

Specific examples of the repeating unit having an acid-decomposable group are shown below, but the present invention is not limited thereto. In a specific example, Rx represents a hydrogen atom, CH ₃ , CF ₃ , or CH ₂ OH. Rxa and Rxb each represent an alkyl group having 1 to 4 carbon atoms. Z represents a substituent containing a polar group, and when it is plural, it is independent. p represents 0 or a positive integer. The substituent containing a polar group represented by Z may, for example, be a linear or branched alkyl group having a hydroxyl group, a cyano group, an amine group, an alkylguanamine group or a sulfonylamino group, or a cycloalkyl group, preferably. It is an alkyl group having a hydroxyl group. As the branched alkyl group, an isopropyl group is particularly preferred. In addition, as a specific example of the repeating unit (c), [0227] to [0233], [0270] to [0272], and Japanese Patent Laid-Open Publication No. 2012-208447 Specific examples described in [0131] are incorporated in the specification of the present application.

[化37]

[化38]

[39]

[化40]

[化41]

[化42]

[化43]

In the case where the resin (P) contains the repeating unit (c) having an acid-decomposable group, the repeating unit (c) having an acid-decomposable group may be one type or two or more types may be used in combination.

In the case where the resin (P) contains the repeating unit (c) having an acid-decomposable group, the repeating unit (c) having an acid-decomposable group in the resin (P) with respect to all the repeating units in the resin (P) The content (total in the case of containing a plurality of) is preferably 5 mol% or more and 80 mol% or less, more preferably 5 mol% or more and 75 mol% or less, and further preferably 10 mol%. Above and 65 mol% or less.

Further, in the specification of the present application, the repeating unit having an acid-decomposable group and an aromatic ring group is applicable to both a repeating unit having an acid-decomposable group and a repeating unit having an aromatic ring group.

(Repeating unit having a lactone group or a sultone group) The resin (P) may contain a repeating unit having a lactone group or a sultone (cyclic sulfonate) group. As the lactone group or the sultone group, any group may be used as long as it contains a lactone structure or a sultone structure, and a group having a 5-membered ring to a 7-membered ring lactone structure or a sultone structure is preferable. It is preferred that the other ring structure is condensed in a 5-membered to 7-membered cyclic lactone structure or a sultone structure in a form of a bicyclic structure or a spiro structure. More preferably, it contains a lactone structure represented by any one of the following general formulae (LC1-1) to (LC1-17) or a general formula (SL1-1) to general formula (SL1-3) Any of the repeating units of the sultone structure represented by either of them. Further, a group having a lactone structure or a sultone structure may be directly bonded to the main chain. As a preferred lactone structure or sultone structure, it is a formula (LC1-1), a formula (LC1-4), a formula (LC1-5), a formula (LC1-6), a formula (LC1) -13) A group represented by the formula (LC1-14).

[化44]

[化45]

The lactone moiety or the sultone moiety may have a substituent (Rb ₂ ) or may have no substituent (Rb ₂ ). Preferred examples of the substituent (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, and an alkoxy group having 1 to 8 carbon atoms. A carbonyl group, a carboxyl group, a halogen atom, a hydroxyl group, a cyano group, an acid-decomposable group or the like. n ₂ represents an integer of 0 to 4. When n ₂ 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 each other to form a ring.

The lactone structure represented by any one of the formula (LC1-1) to the formula (LC1-17) or the formula (SL1-1) to the formula (SL1-3) Examples of the repeating unit of the group of the sultone structure include a repeating unit represented by the following formula (BI).

[Chem. 46]

In the formula (BI), Rb ₀ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms. Preferred examples of the substituent which the alkyl group of Rb ₀ may have include a hydroxyl group and a halogen atom. Examples of the halogen atom of Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb _{0 is} preferably a hydrogen atom or a methyl group. Ab 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, a carboxyl group, or a divalent group obtained by combining these. It is preferably a single bond or a linking group represented by -Ab ₁ -CO ₂ -. Ab ₁ is a linear, branched alkyl, monocyclic or polycyclic cycloalkyl group, preferably a methylene group, an ethyl group, a cyclohexylene group, an adamantyl group, or an extended borneol group. V represents a group represented by any one of the formula (LC1-1) to the formula (LC1-17) and the formula (SL1-1) to the formula (SL1-3).

The repeating unit having a lactone group or a sultone group usually has an optical isomer, and any optical isomer can be used. Further, one optical isomer may be used alone, or a plurality of optical isomers may be used in combination. In the case where an optical isomer is mainly used, the optical purity (enantiomeric excess (ee)) is preferably 90 or more, more preferably 95 or more.

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

[化47]

[48]

In the case where the resin (P) contains a repeating unit having a lactone group or a sultone group, the content of the repeating unit having a lactone group or a sultone group is preferable with respect to all the repeating units in the resin (P). It is 1 mol% to 30 mol%, more preferably 5 mol% to 25 mol%, and further preferably 5 mol% to 20 mol%.

(Repeating unit having a halogen atom in a side chain) The resin (P) may also contain a repeating unit having a halogen atom in a side chain. The repeating unit having a halogen atom in the side chain is not particularly limited as long as it has a halogen atom in the side chain, and examples thereof include a (meth)acrylate repeating unit having a germanium atom, a vinyl repeating unit having a germanium atom, and the like. . The repeating unit having a ruthenium atom is preferably a repeating unit of a structure (acid-decomposable group) which does not have a ruthenium-protected structure (acid-decomposable group) which is decomposed and detached by the action of an acid.

Typically, the repeating unit having a halogen atom in the side chain is a repeating unit containing a group having a halogen atom in the side chain, and examples of the group having a halogen atom include, for example, a trimethyldecyl group, a triethylsulfanyl group, and a trisole. Phenylalkyl, tricyclohexyldecyl, tris-trimethyldecyloxydecyl, tris-trimethyldecylalkyl, methyl bis-trimethyldecyl decyl, methyl bis-trimethyl a cyclic or linear polyoxyalkylene or a cage type as described below, or a dimethyl dimethyl decyl fluorenyl dimethyl group Or a ladder type or a random type of sesquiterpene oxide structure or the like. In the formula, R and R ¹ each independently represent a monovalent substituent. * indicates a bond.

[化49]

The repeating unit having the group may, for example, preferably be a repeating unit derived from an acrylate or methacrylate compound having the group, or a repeating unit derived from a compound having the group and a vinyl group.

The repeating unit having a ruthenium atom is preferably a repeating unit having a sesquioxane structure, whereby an ultrafine (for example, a line width of 50 nm or less) and a high aspect ratio (for example, a film thickness) can be formed. When the pattern has a line width of 2 or more, it exhibits excellent collapse performance. Examples of the sesquiterpene oxide structure include a cage sesquiterpene oxide structure, a ladder type silsesquioxane structure, and a random sesquiterpene alkane structure. Among them, a cage type sesquiterpene oxide structure is preferred. Here, the cage sesquioxane structure refers to a sesquiterpene structure having a cage skeleton. The cage sesquiterpene structure may be a completely caged sesquiterpene structure or an incomplete cage sesquiterpene structure, preferably a fully caged sesquiterpene structure. Further, the ladder type sesquiterpene oxide structure means a sesquiterpene oxide structure having a ladder skeleton. Further, the structure of the random sesquiterpene oxide refers to a structure of a random sesquiterpene oxide having a skeleton.

The cage sesquiterpene oxide structure is preferably a oxoxane structure represented by the following formula (S).

[化50]

In the formula (S), R represents a monovalent substituent. The plurality of Rs may be the same or different. The monovalent substituent is not particularly limited, and specific examples thereof include a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, an alkoxy group, an amine group, a mercapto group, and a blocked mercapto group (for example, a mercapto group (protected by a mercapto group) ), fluorenyl, fluorenylene, phosphino, phosphinyl, decyl, vinyl, hydrocarbyl group having a hetero atom, a group containing a (meth)acryl group, . Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the hetero atom of the hydrocarbon group which may have a hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom and the like. Examples of the hydrocarbon group which may have a hydrocarbon group having a hetero atom include an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination of these. The aliphatic hydrocarbon group may be any of a linear chain, a branched chain, and a cyclic group. Specific examples of the aliphatic hydrocarbon group include a linear or branched alkyl group (particularly, a carbon number of 1 to 30), a linear or branched alkenyl group (especially, a carbon number of 2 to 30), A linear or branched alkynyl group (especially a carbon number of 2 to 30) or the like. Examples of the aromatic hydrocarbon group include an aromatic hydrocarbon group having 6 to 18 carbon atoms such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group.

The repeating unit having a halogen atom is preferably represented by the following formula (I).

[化51]

In the formula (I), L represents a single bond or a divalent linking group. Examples of the divalent linking group include an alkylene group, a -COO-Rt- group, and an -O-Rt- group. In the formula, Rt represents an alkylene group or a cycloalkyl group. L is preferably a single bond or a -COO-Rt- group. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a -CH ₂ - group, a -(CH ₂ ) ₂ - group or a -(CH ₂ ) ₃ - group. In the formula (I), X represents a hydrogen atom or an organic group. The organic group may, for example, be a fluorine atom or an alkyl group which may have a substituent such as a hydroxyl group, and is preferably a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group. In the formula (I), A represents a group containing a halogen atom. Among them, a group represented by the following formula (a) or formula (b) is preferred.

[化52]

In the formula (a), R represents a monovalent substituent. The plurality of Rs may be the same or different. Specific examples and preferred embodiments of R are the same as those of the above formula (S). In the case where A in the above formula (I) is a group represented by the formula (a), the formula (I) is represented by the following formula (I-a).

[化53]

[54]

In the formula (b), R _b represents a hydrocarbon group which may have a hetero atom. Specific examples and preferred embodiments of the hydrocarbon group which may have a hetero atom are the same as those in the above formula (S).

In the case where the resin (P) contains a repeating unit having a ruthenium atom, it may contain a repeating unit having a ruthenium atom, and may also contain two or more kinds of repeating units having a ruthenium atom. In the case where the resin (P) contains a repeating unit having a halogen atom, the content of the repeating unit having a halogen atom is preferably from 1 mol% to 30 mol%, more preferably all the repeating units of the resin (P). It is 1% by mole to 20% by mole, and more preferably 1% by mole to 10% by mole.

Further, in the specification of the present application, a repeating unit having a deuterium atom-protected structure (acid-decomposable group) having a deuterium atom and a polar group decomposed and desorbed by the action of an acid is applicable to a repeating unit having a deuterium atom. Also suitable for repeating units having an acid-decomposable group.

(Other Repeating Units) The resin (P) may also contain other repeating units than those described above. Further, a repeating unit containing an organic group having a polar group, particularly a repeating unit having a polar group-substituted alicyclic hydrocarbon structure may be further included as another repeating unit. Thereby, the substrate adhesion and the developer affinity are improved. The alicyclic hydrocarbon structure which is a polar group-substituted alicyclic hydrocarbon structure is preferably an adamantyl group, a diadamantyl group or a norbornyl group. As the polar group, a hydroxyl group or a cyano group is preferred. Specific examples of the repeating unit having a polar group are listed below, but the present invention is not limited thereto.

[化55]

In the case where the resin (P) contains a repeating unit containing an organic group having a polar group, the content thereof is preferably from 1 mol% to 30 mol%, more preferably from all repeating units in the resin (P). 5 mol% to 25 mol%, and further preferably 5 mol% to 20 mol%.

Further, the resin (P) may further contain a repeating unit having a group (photoacid generating group) which generates an acid by irradiation with actinic rays or radiation as another repeating unit. In this case, it is considered that the repeating unit having a photoacid generating group corresponds to a compound (B) which generates an acid by irradiation with actinic rays or radiation, which will be described later. Examples of such a repeating unit include a repeating unit represented by the following formula (4).

[化56]

R ⁴¹ represents a hydrogen atom or a methyl group. L ⁴¹ represents a single bond or a divalent linking group. L ⁴² represents a divalent linking group. W represents a structural site which is decomposed by irradiation of actinic rays or radiation and generates an acid in a side chain.

In addition, examples of the repeating unit represented by the formula (4) include repeating units described in paragraphs [0094] to [0105] of JP-A-2014-041327.

In the case where the resin (P) contains a repeating unit having a photoacid generating group, the content of the repeating unit having a photoacid generating group is preferably from 1 mol% to 40 mol with respect to all the repeating units in the resin (P). The ear% is more preferably 5 mol% to 35 mol%, and further preferably 5 mol% to 30 mol%.

The resin (P) may further include a cycloalkyl group having a fluorine atom, a group having a fluorine atom, a group having a halogen atom, a carbon number of 6 or more, a carbon number of 5 or more, and a carbon number of 6 or more. a repeating unit of one or more groups of the group consisting of an aryl group and an aralkyl group having 7 or more carbon atoms. When the resin (P) contains the repeating unit, it may be used as a hydrophobic resin to be described later in the resist composition. By using the resin (P) as a hydrophobic resin, the resin (P) having a function as a quenching agent is biased to exist on the surface of the resist film, so that the film thinning can be improved in the positive pattern forming method (top layer) Loss), regarding the negative pattern forming method, the top stretch (T-top shape) can be improved.

In the resist composition, the resin (P) can be used as a resin (main polymer) containing 50% by mass or more with respect to the total solid content of the resist composition, or can be used other than the main polymer (for example). It is used by a hydrophobic resin or a basic compound mentioned later. Further, in the resist composition, the resin (P) may be used alone or in combination of two or more. In the case of being used as a main polymer, the content of the resin (P) is preferably from 50% by mass to 99.9% by mass, and more preferably from 60% by mass to 99.0% by mass, based on the total solid content of the resist composition.

<Compound (B) which generates an acid by actinic rays or radiation> The resist composition preferably contains a compound which generates an acid by actinic rays or radiation (also referred to as "compound (B)", " Photoacid generator", "PAG (Photo Acid Generator)"). The photoacid generator may be in the form of a low molecular compound or may be in a form incorporated into a part of the polymer. Further, the form of the low molecular compound and the form incorporated into a part of the polymer may be used in combination. When the photoacid generator is in the form of a low molecular compound, the molecular weight is preferably 3,000 or less, more preferably 2,000 or less, and still more preferably 1,000 or less. In the case where the photoacid generator is in a form of being incorporated into a part of the polymer, it may be incorporated into a part of the resin (P) contained in the resist composition, or may be incorporated into the resin. (P) Different resins. The number of fluorine atoms possessed by the acid generator can be appropriately adjusted for the purpose of adjusting the cross-sectional shape of the pattern. By adjusting the fluorine atoms, the surface bias of the acid generator in the resist film can be controlled. The more fluorine atoms the acid generator has, the more it is present on the surface. The photoacid generator is preferably in the form of a low molecular compound. The photoacid generator is not particularly limited, and it is preferred to generate an organic acid such as sulfonic acid or bis(alkylsulfonyl) fluorene by irradiation with actinic rays or radiation, preferably electron beam or extreme ultraviolet rays. A compound of at least one of an imine or a tris(alkylsulfonyl)methide. The photoacid generator is more preferably a compound represented by the following formula (ZI), formula (ZII) or formula (ZIII).

[化57]

In the above formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represent an organic group. The carbon number of the organic groups of R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is usually from 1 to 30, preferably from 1 to 20. Further, two of R ₂₀₁ to R ₂₀₃ may be bonded to each other to form a ring structure, and may contain an oxygen atom, a sulfur atom, an ester bond, a guanamine bond or a carbonyl group in the ring. Examples of the group formed by the two bonds of R ₂₀₁ to R ₂₀₃ include an alkylene group (for example, a butyl group and a pentyl group). Z ^- represents a non-nucleophilic anion (an anion having a significantly lower ability to cause a nucleophilic reaction).

Examples of the non-nucleophilic anion include a sulfonate anion (an aliphatic sulfonate anion, an aromatic sulfonate anion, a camphorsulfonate anion, etc.), a carboxylate anion (an aliphatic carboxylate anion, an aromatic carboxylate anion, and an aromatic). An alkyl carboxylate anion or the like), a sulfonyl quinone imine anion, a bis(alkylsulfonyl) quinone imine anion, a tris(alkylsulfonyl) methide anion, or the like.

The aliphatic moiety in the aliphatic sulfonate anion and the aliphatic carboxylate anion may be an alkyl group or a cycloalkyl group, and preferably a linear or branched alkyl group having 1 to 30 carbon atoms and a carbon number of 3 to 3 30 cycloalkyl.

The aromatic group in the aromatic sulfonate anion and the aromatic carboxylate anion is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group or a naphthyl group.

The recited alkyl, cycloalkyl and aryl groups may have a substituent. Specific examples of the halogen atom include a halogen atom such as a nitro group or a fluorine atom, a carboxyl group, a hydroxyl group, an amine group, a cyano group, an alkoxy group (preferably having a carbon number of 1 to 15), and a cycloalkyl group (preferably having a carbon number of 3). ～15), an aryl group (preferably having a carbon number of 6 to 14), an alkoxycarbonyl group (preferably having a carbon number of 2 to 7), a mercapto group (preferably having a carbon number of 2 to 12), and an alkoxycarbonyl oxygen. a base (preferably having a carbon number of 2 to 7), an alkylthio group (preferably having a carbon number of 1 to 15), an alkylsulfonyl group (preferably having a carbon number of 1 to 15), and an alkylimidosulfonyl group. (preferably having a carbon number of 1 to 15), an aryloxysulfonyl group (preferably having a carbon number of 6 to 20), an alkylaryloxysulfonyl group (preferably having a carbon number of 7 to 20), and a ring. Alkylaryloxysulfonyl (preferably having a carbon number of 10 to 20), an alkyloxyalkyloxy group (preferably having a carbon number of 5 to 20), or a cycloalkylalkyloxyalkyloxy group (preferably having a carbon number of 8 to 20). Further, as the aryl group and the ring structure of each group, an alkyl group (preferably having 1 to 15 carbon atoms) may be mentioned as a substituent.

The aralkyl group in the aralkylcarboxylate anion is preferably an aralkyl group having 7 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group or a naphthylbutyl group. Wait.

Examples of the sulfonyl quinone imine anion include a saccharin anion.

The alkyl group in the bis(alkylsulfonyl)phosphonium anion and the tris(alkylsulfonyl)methide anion is preferably an alkyl group having 1 to 5 carbon atoms. Examples of the substituent of the alkyl group include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, an alkyloxysulfonyl group, an aryloxysulfonyl group, and a cycloalkyl group. The oxysulfolyl group or the like is preferably a fluorine atom or an alkyl group substituted by a fluorine atom. Further, the alkyl groups in the bis(alkylsulfonyl) quinone imine anion may be bonded to each other to form a ring structure. Thereby, the acid strength increases.

Examples of the other non-nucleophilic anion include phosphorus fluoride (for example, PF ₆ ^- ), boron fluoride (for example, BF ₄ ^- ), and cesium fluoride (for example, SbF ₆ ^- ).

As the non-nucleophilic anion, an aliphatic sulfonate anion having at least the α position of the sulfonic acid substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group substituted by a fluorine atom are preferred. A bis(alkylsulfonyl) quinone imine anion, a tri(alkylsulfonyl) methide anion having an alkyl group substituted with a fluorine atom. The non-nucleophilic anion is more preferably a perfluoroaliphatic sulfonate anion (and more preferably a carbon number of 4 to 8), a benzenesulfonate anion having a fluorine atom, and more preferably a nonafluorobutanesulfonate anion or a perfluorooctane. Sulfonic acid anion, pentafluorobenzenesulfonate anion, 3,5-bis(trifluoromethyl)benzenesulfonate anion.

From the viewpoint of acid strength, in order to improve the sensitivity, it is preferred that the pKa of the generated acid is -1 or less.

Further, as the non-nucleophilic anion, an anion represented by the following formula (AN1) may be mentioned as a preferred embodiment.

[化58]

In the formula, Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom or an alkyl group, and when there are a plurality of R ¹ and R ^{2 , they} may be the same or different. L represents a divalent linking group, and when there are a plurality of L, the L may be the same or different. A represents a cyclic organic group. x represents an integer of 1 to 20, y represents an integer of 0 to 10, and z represents an integer of 0 to 10.

The general formula (AN1) will be described in more detail. The alkyl group in the alkyl group substituted with a fluorine atom of Xf preferably has a carbon number of from 1 to 10, more preferably a carbon number of from 1 to 4. Further, the alkyl group substituted with a fluorine atom of Xf is preferably a perfluoroalkyl group. Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. Specific examples of Xf include a fluorine atom, CF ₃ , C ₂ F ₅ , C ₃ F ₇ , C ₄ F ₉ , CH ₂ CF ₃ , CH ₂ CH ₂ CF ₃ , CH ₂ C ₂ F ₅ , CH ₂ CH ₂ C _{2 .} F ₅ , CH ₂ C ₃ F ₇ , CH ₂ CH ₂ C ₃ F ₇ , CH ₂ C ₄ F ₉ , CH ₂ CH ₂ C ₄ F ₉ , of which a fluorine atom or CF _{3 is} preferred. Particularly preferred are two Xf atoms which are fluorine atoms.

The alkyl group of R ¹ and R ² may have a substituent (preferably a fluorine atom), and preferably has a carbon number of 1 to 4. Further, it is preferably a perfluoroalkyl group having 1 to 4 carbon atoms. Specific examples of the alkyl group having a substituent of R ¹ and R ² include CF ₃ , C ₂ F ₅ , C ₃ F ₇ , C ₄ F ₉ , C ₅ F ₁₁ , C ₆ F ₁₃ , and C ₇ F . ₁₅ , C ₈ F ₁₇ , CH ₂ CF ₃ , CH ₂ CH ₂ CF ₃ , CH ₂ C ₂ F ₅ , CH ₂ CH ₂ C ₂ F ₅ , CH ₂ C ₃ F ₇ , CH ₂ CH ₂ C ₃ F ₇ And CH ₂ C ₄ F ₉ , CH ₂ CH ₂ C ₄ F ₉ , wherein CF _{3 is} preferred. R ¹ and R ^{2 are} preferably a fluorine atom or CF ₃ .

x is preferably from 1 to 10, more preferably from 1 to 5. y is preferably 0 to 4, more preferably 0. z is preferably from 0 to 5, more preferably from 0 to 3. The divalent linking group of L is not particularly limited, and examples thereof include -COO-, -OCO-, -CO-, -O-, -S-, -SO-, -SO ₂ -, alkylene, and cycloalkane. The base group, the extended alkenyl group or the plurality of linked groups formed by a plurality of bonds are preferably a linking group having a total carbon number of 12 or less. Among them, preferred are -COO-, -OCO-, -CO-, -O-, and more preferably -COO-, -OCO-.

The cyclic organic group of A is not particularly limited as long as it has a cyclic structure, and examples thereof include an alicyclic group, an aryl group, and a heterocyclic group (including those having aromaticity or not having aromaticity). Wait. As the alicyclic group, it may be a single ring or a polycyclic ring, preferably a monocyclic cycloalkyl group such as a cyclopentyl group, a cyclohexyl group or a cyclooctyl group, a norbornyl group, a tricyclodecyl group or a tetracyclodecane. A polycyclic cycloalkyl group such as a tetracyclododecyl group or an adamantyl group. Among them, from the viewpoint of suppressing the diffusibility in the film in the post-exposure heating step and increasing the Mask Error Enhancement Factor (MEEF), it is preferably a norbornyl group, a tricyclodecyl group, or a tetracyclic ring. An alicyclic group having a large volume structure having a carbon number of 7 or more, such as a decyl group, a tetracyclododecyl group or an adamantyl group. Examples of the aryl group include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. Examples of the heterocyclic group include those derived from a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, and a pyridine ring. Among them, those derived from a furan ring, a thiophene ring, and a pyridine ring are preferred.

In addition, as a cyclic organic group, a lactone structure is mentioned, and as a specific example, the lactone structure represented by general formula (LC1-1) - general formula (LC1-17) is mentioned.

The cyclic organic group may have a substituent, and examples of the substituent include an alkyl group (which may be any of a straight chain, a branched group, and a cyclic group, preferably a carbon number of 1 to 12), and a cycloalkyl group. (may be any of a monocyclic, polycyclic, or spiro ring, preferably having a carbon number of 3 to 20), an aryl group (preferably having a carbon number of 6 to 14), a hydroxyl group, an alkoxy group, an ester group, or a decylamino group. A urethane group, a urea group, a thioether group, a sulfonylamino group, a sulfonate group or the like. Further, the carbon constituting the cyclic organic group (carbon which contributes to the formation of a ring) may be a carbonyl carbon.

Examples of the organic group of R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include an aryl group, an alkyl group, and a cycloalkyl group. Of R ₂₀₁ , R ₂₀₂ and R ₂₀₃ , preferably at least one is an aryl group, and more preferably all three are aryl groups. The aryl group may be a heteroaryl group such as a hydrazine residue or a pyrrole residue, in addition to a phenyl group or a naphthyl group. The alkyl group and the cycloalkyl group of R ₂₀₁ to R ₂₀₃ are preferably a linear or branched alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms. The alkyl group is more preferably a methyl group, an ethyl group, a n-propyl group, an isopropyl group or an n-butyl group. The cycloalkyl group is more preferably a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group or a cycloheptyl group. These groups may further have a substituent. Examples of the substituent include a halogen atom such as a nitro group or a fluorine atom, a carboxyl group, a hydroxyl group, an amine group, a cyano group, an alkoxy group (preferably having a carbon number of 1 to 15), and a cycloalkyl group (preferably having a carbon number of 3). ～15), an aryl group (preferably having a carbon number of 6 to 14), an alkoxycarbonyl group (preferably having a carbon number of 2 to 7), a mercapto group (preferably having a carbon number of 2 to 12), and an alkoxycarbonyl oxygen. The base (preferably having a carbon number of 2 to 7) or the like is not limited thereto.

Preferred examples of the anion represented by the formula (AN1) include the followings. In the following examples, A represents a cyclic organic group. SO ₃ -CF ₂ -CH ₂ -OCO-A, SO ₃ -CF ₂ -CHF-CH ₂ -OCO-A, SO ₃ -CF ₂ -COO-A, SO ₃ -CF ₂ -CF ₂ -CH ₂ - A, SO ₃ -CF ₂ -CH(CF ₃ )-OCO-A

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

The aryl group, the alkyl group and the cycloalkyl group of R ₂₀₄ to R ₂₀₇ are the same as those described for the aryl group, the alkyl group or the cycloalkyl group as R ₂₀₁ to R ₂₀₃ in the compound (ZI). The aryl group, the alkyl group or the cycloalkyl group of R ₂₀₄ to R ₂₀₇ may have a substituent. The substituent may be a substituent which the aryl group, the alkyl group or the cycloalkyl group of R ₂₀₁ to R ₂₀₃ in the compound (ZI) may have.

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

In the present invention, the photoacid generator is preferably produced by irradiation with an electron beam or extreme ultraviolet rays from the viewpoint of suppressing diffusion of an acid generated by exposure to a non-exposed portion to improve the resolution. A compound having an acidity of more than 130 Å ^{3 (} more preferably a sulfonic acid), more preferably a compound having a volume of 190 Å ³ or more (more preferably a sulfonic acid), and preferably a volume of 270 Å. A compound having an acid of ³ or more in size (more preferably, a sulfonic acid) is particularly preferably a compound which produces an acid having a volume of 400 Å ³ or more (more preferably, a sulfonic acid). Among these, the volume is preferably 2,000 Å ³ or less, and more preferably 1,500 Å ³ or less from the viewpoint of sensitivity or solvent solubility of the coating solvent. The value of the volume was obtained by using "WinMOPAC" manufactured by Fujitsu Co., Ltd. That is, the chemical structure of the acid of each case is first input, and then the structure is taken as the initial structure, and the most stable stereo configuration of each acid is determined by using the molecular force field calculation of the MM3 method, and then the most stable stereostructure is The molecular orbital calculation using the PM3 method is performed, whereby the "accessible volume" of each acid can be calculated.

As a photoacid generator, a paragraph [0368] to a paragraph [0377] of Japanese Patent Laid-Open No. Hei. No. 2014-41328, and a paragraph [0240] to a paragraph [0262] of the Japanese Patent Laid-Open Publication No. 2013-228681 (corresponding US patents) [0339] of the specification of the publication No. 2015/004533, the contents are incorporated in the specification of the present application. Moreover, as a preferable specific example, the following compounds are mentioned, but it is not limited to these.

[化59]

[60]

[化61]

[化62]

The photoacid generator may be used alone or in combination of two or more. The content of the photoacid generator in the resist composition is preferably from 0.1% by mass to 50% by mass, more preferably from 5% by mass to 50% by mass, based on the total solid content of the resist composition. It is 8 mass% to 40 mass%. In particular, the content of the photoacid generator is preferably from 10% by mass to 40% by mass, and most preferably from 10% by mass to 35%, in terms of high sensitivity and high resolution in the case of electron beam or extreme ultraviolet light exposure. %. The photoacid generator may be used alone or in combination of two or more.

<Resist Solvent> The resist composition preferably contains a solvent (also referred to as a "resist solvent"). The solvent may also contain isomers (compounds of the same structure with the same number of atoms). Further, the isomer may be contained alone or in combination of plural kinds. The solvent preferably comprises (M1) propylene glycol monoalkyl ether carboxylate, and (M2) is selected from the group consisting of propylene glycol monoalkyl ether, lactate, acetate, alkoxypropionate, chain ketone, cyclic At least one of at least one of the group consisting of a ketone, a lactone, and an alkylene carbonate. The solvent may further contain components other than the component (M1) and the component (M2).

The component (M1) is preferably at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, and propylene glycol monoethyl ether acetate, particularly preferably propylene glycol monomethyl Ether acetate.

As the component (M2), the following components are preferable. As the propylene glycol monoalkyl ether, propylene glycol monomethyl ether or propylene glycol monoethyl ether is preferred. As the lactate, ethyl lactate, butyl lactate or propyl lactate is preferred. As the acetate, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, isoamyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, Or 3-methoxybutyl acetate. Also preferred is butyl butyrate. As the alkoxypropionate, methyl 3-methoxy propionate (MMP) or ethyl 3-ethoxypropionate (EEP) is preferred. As the chain ketone, 1-octyl ketone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, Diisobutyl ketone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetyl ketone, acetonyl acetone, ionone, diacetone alcohol, acetamyl methanol, acetophenone, Methylnaphthyl ketone, or methyl amyl ketone. As the cyclic ketone, methylcyclohexanone, isophorone, or cyclohexanone is preferred. As the lactone, γ-butyrolactone is preferred. As the alkylene carbonate, a propyl carbonate is preferred.

As the component (M2), more preferred is propylene glycol monomethyl ether, ethyl lactate, ethyl 3-ethoxypropionate, methyl amyl ketone, cyclohexanone, butyl acetate, amyl acetate, γ-butane Ester or propyl carbonate.

In addition to the above components, an ester solvent having 7 or more (preferably 7 to 14, more preferably 7 to 12, more preferably 7 to 10) and having 2 or less hetero atoms is preferably used.

Preferable examples of the ester solvent having 7 or more carbon atoms and 2 or less hetero atoms include pentyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, and C. Amyl acetate, hexyl propionate, butyl propionate, isobutyl isobutyrate, heptyl propionate, butyl butyrate, etc., particularly preferably isoamyl acetate.

As the component (M2), a component having a firing point (hereinafter, also referred to as fp) of 37 ° C or higher is preferably used. As such a component (M2), propylene glycol monomethyl ether (fp: 47 ° C), ethyl lactate (fp: 53 ° C), ethyl 3-ethoxypropionate (fp: 49 ° C), methyl group is preferred. Amyl ketone (fp: 42 ° C), cyclohexanone (fp: 44 ° C), amyl acetate (fp: 45 ° C), methyl 2-hydroxyisobutyrate (fp: 45 ° C), γ-butyrolactone (fp: 101 ° C) or propyl carbonate (fp: 132 ° C). Among these, propylene glycol monoethyl ether, ethyl lactate, amyl acetate, or cyclohexanone is preferable, and propylene glycol monoethyl ether or ethyl lactate is particularly preferable. In addition, the term "fire point" as used herein refers to a value described in the reagent catalogue of Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich.

The solvent preferably contains the component (M1). More preferably, the solvent contains only the component (M1) or a mixed solvent of the component (M1) and other components. In the latter case, the solvent further preferably contains both the component (M1) and the component (M2).

The mass of the component (M1) and the component (M2) is preferably in the range of 100:0 to 15:85, more preferably in the range of 100:0 to 40:60, and more preferably in the range of 100:0 to 60. :40 within range. That is, the solvent preferably contains only the component (M1), or both the component (M1) and the component (M2), and the masses thereof are as described below. That is, in the latter case, the mass of the component (M1) relative to the component (M2) is preferably 15/85 or more, more preferably 40/60 or more, and still more preferably 60/40 or more. According to this configuration, the number of development defects can be further reduced.

In the case where the solvent contains both the component (M1) and the component (M2), the mass ratio of the component (M1) to the component (M2) is, for example, 99/1 or less.

As described above, the solvent may further contain components other than the component (M1) and the component (M2). In this case, the content of the components other than the component (M1) and the component (M2) is preferably in the range of 5 mass% to 30 mass% with respect to the total amount of the solvent.

The content of the solvent in the resist composition is preferably set so that the solid content concentration of the total component is from 1% by mass to 40% by mass, and more preferably from 1% by mass to 30% by mass. Further, it is preferably set so as to be 1% by mass to 20% by mass. If so, the coatability of the resist composition can be further improved. The solid content concentration of the resist composition can be appropriately adjusted for the purpose of adjusting the thickness of the resulting resist film.

<Crosslinking Agent> The resist composition may also contain a crosslinking agent. In the present specification, a cross-linking agent typically refers to a compound which reacts with a resin by an action of an acid to form a crosslinked structure. The crosslinking agent is preferably a compound having two or more crosslinkable groups in the molecule, and examples thereof include a methylol group-containing crosslinking agent (having at least a methylol group (hydroxymethyl group) and an alkoxymethyl group. One of the crosslinking agents), an epoxy crosslinking agent (a crosslinking agent having an epoxy group), an oxetane crosslinking agent (a crosslinking agent having an oxetanyl group), and an isocyanate crosslinking agent The crosslinking agent (crosslinking agent having an isocyanate group) or the like is preferably a methylol crosslinking agent or an epoxy crosslinking agent, more preferably a methylol crosslinking agent, and more preferably two or more. A crosslinking agent of a methylol group, a crosslinking agent having two or more alkoxymethyl groups, or a crosslinking agent having one or more methylol groups and having one or more alkoxymethyl groups.

The crosslinking agent may be a low molecular compound or a polymer compound (for example, a compound having a crosslinking compound supported on the polymer compound, a compound containing a repeating unit having a crosslinkable group, or the like). In the case where the crosslinking agent is a low molecular weight, the molecular weight is preferably from 100 to 1,000, more preferably from 200 to 900, most preferably from 300 to 800. Preferred examples of the crosslinking agent include a hydroxymethylated or alkoxymethylated phenol compound, an alkoxymethylated melamine compound, an alkoxymethyl glycoluran compound, and an alkoxymethylation. Urea compound. As a particularly preferable crosslinking agent, a phenol derivative having a molecular weight of 1200 or less and having a total of two or more benzene rings in the molecule and further having two or more hydroxymethyl groups or alkoxymethyl groups or Alkoxymethyl glycoluril derivatives. As the alkoxymethyl group, a methoxymethyl group or an ethoxymethyl group is preferred.

In the example of the crosslinking agent, a phenol derivative having a hydroxymethyl group can be obtained by reacting a phenol compound having no corresponding hydroxymethyl group with formaldehyde under a base catalyst. Further, a phenol derivative having an alkoxymethyl group can be obtained by reacting a phenol derivative having a corresponding hydroxymethyl group with an alcohol under an acid catalyst.

Examples of other preferable crosslinking agents include an alkoxymethylated melamine-based compound, an alkoxymethyl-glycoluride-based compound, and an alkoxymethylated urea-based compound having N- A compound of a hydroxymethyl group or an N-alkoxymethyl group.

Examples of such a compound include hexamethoxymethyl melamine, hexaethoxymethyl melamine, tetramethoxymethyl glycoluril, and 1,3-bismethoxymethyl-4,5-dimethoxy extension. Ethylurea, bis-methoxymethylurea, and the like are disclosed in EP 0,133,216 A, West German Patent No. 3,634,671, West German Patent No. 3,711,264, EP 0,212,482 A. The most preferred examples of the specific examples of the crosslinking agent are listed below.

[化63]

In the formula, L ₁ to L ₈ each independently represent a hydrogen atom, a hydroxymethyl group, a methoxymethyl group, an ethoxymethyl group or an alkyl group having 1 to 6 carbon atoms. In one aspect of the invention, the crosslinking agent is preferably a compound represented by the following formula (CI).

[化64]

In the general formula (CI), R ₁ and R ₆ each independently represent a hydrogen atom or a hydrocarbon group having 5 or less carbon atoms. R ₂ and R ₅ each independently represent an alkyl group, a cycloalkyl group, an aryl group or a fluorenyl group. R ₃ and R ₄ each independently represent a hydrogen atom or an organic group having 2 or more carbon atoms. R ₃ and R ₄ may be bonded to each other to form a ring.

In one embodiment of the present invention, R ₁ and R _{6 are} preferably a hydrocarbon group having 5 or less carbon atoms, more preferably a hydrocarbon group having 4 or less carbon atoms, and particularly preferably a methyl group, an ethyl group, a propyl group or an isopropyl group. .

The alkyl group represented by R ₂ and R ₅ is, for example, preferably an alkyl group having 1 to 6 carbon atoms, and the cycloalkyl group is preferably a cycloalkyl group having 3 to 12 carbon atoms as an aryl group. For example, an aryl group having 6 to 12 carbon atoms is preferable, and as the mercapto group, for example, an anthracene group having 1 to 6 carbon atoms in the alkyl group is preferable. In one embodiment of the present invention, R ₂ and R _{5 are} preferably an alkyl group, more preferably an alkyl group having 1 to 6 carbon atoms, particularly preferably a methyl group.

Examples of the organic group having 2 or more carbon atoms represented by R ₃ and R ₄ include an alkyl group having 2 or more carbon atoms, a cycloalkyl group, an aryl group, and the like. Further, R ₃ and R ₄ are preferably bonded to each other. The ring to be described in detail below is formed.

Examples of the ring formed by bonding R ₃ and R _{4 to} each other include an aromatic or non-aromatic hydrocarbon ring, an aromatic or non-aromatic hetero ring, or a combination of two or more of these rings. Polycyclic fused ring.

These rings may have a substituent, and examples of such a substituent include an alkyl group, a cycloalkyl group, an alkoxy group, a carboxyl group, an aryl group, an alkoxymethyl group, a decyl group, an alkoxycarbonyl group, and a nitro group. Halogen, or hydroxyl group, and the like.

Hereinafter, specific examples of the ring formed by bonding R ₃ and R _{4 to} each other will be described. * in the formula indicates a linking site with a phenol nucleus.

[化65]

In one embodiment of the present invention, it is preferred that R ₃ and R ₄ in the formula (CI) are bonded to each other to form a polycyclic fused ring containing a benzene ring, and more preferably to form a fluorene structure. The crosslinking agent is preferably bonded to R ₃ and R ₄ in the general formula (CI) to form an anthracene structure represented by the following formula (Ia).

[化66]

In the formula, R ₇ and R ₈ each independently represent a substituent. Examples of the substituent include an alkyl group, a cycloalkyl group, an alkoxy group, an aryl group, an alkoxymethyl group, a decyl group, an alkoxycarbonyl group, a nitro group, a halogen group, or a hydroxyl group. N1 and n2 each independently represent an integer of 0 to 4, and preferably represent 0 or 1. * indicates the site of attachment to the phenol nucleus.

Further, in one aspect of the invention, the crosslinking agent is preferably represented by the following formula (I-b).

[67]

In the formula, R _1b and R _6b each independently represent an alkyl group having 5 or less carbon atoms. R _2b and R _5b each independently represent an alkyl group having 6 or less carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms. Z represents a group of atoms necessary to form a ring together with a carbon atom in the formula. The ring formed by Z together with the carbon atom in the formula is the same as the ring formed by bonding R ₃ and R _{4 to} each other in the description of the above formula (CI).

In one aspect of the invention, the crosslinking agent is preferably a compound having four or more aromatic rings in the molecule and having two alkoxymethyl groups and/or hydroxymethyl groups in total.

Next, a method for producing a crosslinking agent represented by the formula (CI) will be described. The bisphenol compound which is a mother nucleus of the crosslinking agent represented by the general formula (CI) is usually synthesized by subjecting a corresponding two molecules of a phenol compound to a corresponding one molecule of a ketone in a dehydration condensation reaction in the presence of an acid catalyst.

The obtained bisphenol is treated with paraformaldehyde and dimethylamine, and subjected to aminomethylation, whereby an intermediate represented by the following formula (I-C) is obtained. Then, the target acid crosslinking agent is obtained via acetylation, deacetylation, and alkylation.

[化68]

In the formula, R ₁ , R ₃ , R ₄ and R ₆ have the same meanings as the respective groups of the formula (CI).

In the present synthesis method, it is difficult to form an oligomer as compared with the conventional synthesis method by a hydroxymethyl group under a basic condition (for example, JP-A-2008-273844), and thus the effect of suppressing particle formation is suppressed. Specific examples of the crosslinking agent are shown below.

[化69]

The crosslinking agent may be used singly or in combination of two or more. From the viewpoint of a good pattern shape, it is preferred to use two or more types in combination.

When the resist composition contains a crosslinking agent, the content of the crosslinking agent is preferably from 0.1% by mass to 40% by mass, more preferably from 1% by mass to 5% by mass based on the total solid content of the resist composition. The mass% is further preferably 5% by mass to 30% by mass.

(Basic Compound) The resist composition preferably contains a basic compound in order to reduce the change in performance caused by the passage of time from exposure to heating. The basic compound is preferably a compound having a structure represented by the following formula (E-1) to formula (E-5). Further, the resin (P) may also be used as a basic compound.

[化70]

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

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. In the formula (E-5), R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represent an alkyl group having 1 to 20 carbon atoms. The alkyl groups in the general formula (E-1) and the general formula (E-5) are more preferably unsubstituted.

Preferred examples of the compound include anthracene, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine. Preferred examples of the compound include: a compound having an imidazole structure, a diazabicyclo structure, a ruthenium hydroxide structure, a ruthenium carboxylate structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and/or an ether bond, An aniline derivative of 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 and 1,5-diazabicyclo[4,3,0]non-5-ene. 1,8-diazabicyclo[5,4,0]undec-7-ene, and the like. Examples of the compound having a ruthenium hydroxide structure include triarylsulfonium hydroxide, benzamidine methylhydrazine hydroxide, and cesium hydroxide having a 2-oxoalkyl group. Specific examples thereof include triphenylphosphonium hydroxide and hydrogen hydroxide. Tris(t-butylphenyl)anthracene, bis(t-butylphenyl)phosphonium hydroxide, benzamidine methylthiophene hydroxide, 2-oxopropylthiophene hydroxide, and the like. The compound having a ruthenium carboxylate salt structure is one in which the anion portion of the compound having a ruthenium hydroxide structure is a carboxylate, and examples thereof include an acetate, an adamantane-1-carboxylate, and a perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri(n-butyl)amine and tri(n-octyl)amine. Examples of the aniline compound include 2,6-diisopropylaniline, N,N-dimethylaniline, N,N-dibutylaniline, and N,N-dihexylaniline. Examples of the alkylamine derivative having a hydroxyl group and/or an ether bond include ethanolamine, diethanolamine, triethanolamine, tris(methoxyethoxyethyl)amine, and the like. Examples of the aniline derivative having a hydroxyl group and/or an ether bond include N,N-bis(hydroxyethyl)aniline.

Further preferred examples of the basic compound include an amine compound having a phenoxy group and an ammonium salt compound having a phenoxy group.

The amine compound may be a primary, secondary or tertiary amine compound, preferably an amine compound having at least one alkyl group bonded to a nitrogen atom. The amine compound is more preferably a tertiary amine compound. As long as at least one alkyl group (preferably having 1 to 20 carbon atoms) of the amine compound is bonded to the nitrogen atom, a cycloalkyl group (preferably having a carbon number of 3 to 20) or an aryl group (preferably carbon) other than the alkyl group is preferred. The number 6 to 12) may also be bonded to a nitrogen atom. Further, the amine compound preferably has an oxygen atom in the alkyl chain and forms an oxygen-extended alkyl group. The number of the oxygen alkyl groups is one or more in the molecule, preferably from 3 to 9, and more preferably from 4 to 6. In the oxygen alkyl group, an oxygen extended ethyl group (-CH ₂ CH ₂ O-) or an oxygen extended propyl group (-CH(CH ₃ )CH ₂ O- or -CH ₂ CH ₂ CH ₂ O-) is preferred. And then preferably oxygen extended ethyl.

The ammonium salt compound may be a primary, secondary, tertiary or tertiary ammonium salt compound, preferably an ammonium salt compound in which at least one alkyl group is bonded to a nitrogen atom. The cycloalkyl group (preferably having a carbon number of 3 to 20) or an aryl group (preferably, as long as at least one alkyl group (preferably having 1 to 20 carbon atoms) of the ammonium salt compound is bonded to the nitrogen atom. The carbon number 6 to 12) may also be bonded to a nitrogen atom. The ammonium salt compound preferably has an oxygen atom in the alkyl chain and forms an oxygen-extended alkyl group. The number of the oxygen alkyl groups is one or more in the molecule, preferably from 3 to 9, and more preferably from 4 to 6. In the oxygen alkyl group, an oxygen extended ethyl group (-CH ₂ CH ₂ O-) or an oxygen extended propyl group (-CH(CH ₃ )CH ₂ O- or -CH ₂ CH ₂ CH ₂ O-) is preferred. And then preferably oxygen extended ethyl. The anion of the ammonium salt compound may, for example, be a halogen atom, a sulfonate, a borate or a phosphate. Among them, a halogen atom or a sulfonate is preferred. The halogen atom is particularly preferably a chloride, a bromide or an iodide, and a sulfonate is particularly preferably an organic sulfonate having 1 to 20 carbon atoms. The organic sulfonate may, for example, be an alkylsulfonate or an arylsulfonate having 1 to 20 carbon atoms. The alkyl group of the alkyl sulfonate may have a substituent, and examples of the substituent include fluorine, chlorine, bromine, alkoxy, decyl, aryl and the like. Specific examples of the alkyl sulfonate include methanesulfonate, ethanesulfonate, butanesulfonate, hexanosulfonate, octanesulfonate, benzylsulfonate, trifluoromethanesulfonate, and pentafluorobenzene. Ethane sulfonate, nonafluorobutane sulfonate, and the like. Examples of the aryl group of the arylsulfonate include a benzene ring, a naphthalene ring, and an anthracene ring. The benzene ring, the naphthalene ring and the anthracene ring may have a substituent, and as the substituent, a linear or branched alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms is preferable. Specific examples of the linear or branched alkyl group and the cycloalkyl group include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a n-hexyl group, and a cyclohexyl group. The other substituent may, for example, be an alkoxy group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a nitro group, a decyl group or a decyloxy group.

The amine compound having a phenoxy group or the ammonium salt compound having a phenoxy group means a phenoxy group having a terminal group on the opposite side to the nitrogen atom of the alkyl group of the amine compound or the ammonium salt compound. The phenoxy group may have a substituent. Examples of the substituent of the phenoxy group include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylate group, a sulfonate group, an aryl group, an aralkyl group, and a decyloxy group. , aryloxy and the like. The substitution position of the substituent may be any of 2 to 6 positions. The number of substituents may be any of the range of 1 to 5.

It is preferred to have at least one oxygen-extended alkyl group between the phenoxy group and the nitrogen atom. The number of the oxygen alkyl groups is one or more in the molecule, preferably from 3 to 9, and more preferably from 4 to 6. In the oxygen alkyl group, an oxygen extended ethyl group (-CH ₂ CH ₂ O-) or an oxygen extended propyl group (-CH(CH ₃ )CH ₂ O- or -CH ₂ CH ₂ CH ₂ O-) is preferred. And then preferably oxygen extended ethyl.

The amine compound having a phenoxy group can be obtained by heating a primary amine or a secondary amine having a phenoxy group with a halogenated alkyl ether and reacting it with sodium hydroxide, potassium hydroxide or tetraalkylammonium. After the aqueous solution of the strong base is used, the extraction is carried out using an organic solvent such as ethyl acetate or chloroform. Alternatively, the amine compound having a phenoxy group can also be obtained by heating a primary or secondary amine with a halogenated alkyl ether having a phenoxy group at the end to cause reaction, and adding sodium hydroxide or potassium hydroxide. After an aqueous solution of a strong base such as tetraalkylammonium is extracted with an organic solvent such as ethyl acetate or chloroform.

(Compound (PA) having a proton-receptive functional group and decomposing by irradiation with actinic rays or radiation to cause a decrease in proton acceptor property, disappearance, or change from proton acceptor to acid) The ray-sensitive or radiation-sensitive resin composition may further contain a proton-receptive functional group, and is decomposed by irradiation with actinic rays or radiation to cause a decrease in proton acceptor property, disappearance, or change from proton acceptor property to A compound of an acidic compound [hereinafter, also referred to as a compound (PA)] is used as a basic compound.

The proton acceptor functional group refers to a functional group having a group or an electron which can electrostatically interact with a proton, and for example, a functional group having a macrocyclic structure such as a cyclic polyether, or a A functional group that contributes to the nitrogen atom of a π-conjugated non-shared electron pair. The nitrogen atom having an unshared electron pair which does not contribute to π conjugate is, for example, a nitrogen atom having a partial structure represented by the following general formula.

[71]

Preferred examples of the partial structure of the proton acceptor functional group include a crown ether, an azacrown ether, a primary amine to a tertiary amine, a pyridine, an imidazole, and a pyrazine structure.

The compound (PA) is decomposed by irradiation with actinic rays or radiation to produce a compound having reduced or disappeared proton acceptor properties or changed from proton acceptor to acid. Here, the decrease or disappearance of proton acceptor property or the change from proton acceptor property to acidity means a change in proton acceptor property due to addition of a proton in a proton acceptor functional group, specifically It means that when a proton-addition product is formed from a compound (PA) having a proton-receptive functional group and a proton, the equilibrium constant in the chemical equilibrium is decreased.

Specific examples of the compound (PA) include the following compounds. Further, as a specific example of the compound (PA), for example, those described in paragraphs 0021 to 0, 026 of JP-A-2014-41328, and paragraphs 0108 to 0116 of JP-A-2014-134686, These contents are incorporated into the present specification.

[化72]

[化73]

[化74]

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

The content of the basic compound is preferably 0.001% by mass to 10% by mass, and more preferably 0.01% by mass to 5% by mass based on the solid content of the resist composition.

The ratio of use of the photoacid generator to the basic compound in the resist composition is preferably a photoacid generator/basic compound (mole ratio) = 2.5 to 300. In other words, from the viewpoint of the sensitivity and the resolution, the molar ratio is preferably 2.5 or more, and the molarity is preferably lowered from the viewpoint of suppressing the decrease in the resolution due to the coarsening of the pattern after the elapse of the post-exposure heat treatment. It is 300 or less. The photoacid generator/basic compound (mole ratio) is more preferably 5.0 to 200, and still more preferably 7.0 to 150.

As the basic compound, for example, a compound (an amine compound, a guanamine group-containing compound, a urea compound, a nitrogen-containing heterocyclic compound, or the like) described in paragraphs 0140 to 0144 of JP-A-2013-11833 can be used.

<Hydrophobic Resin> The resist composition may contain a hydrophobic resin. As the hydrophobic resin, a hydrophobic resin different from the resin (P) may be contained independently of the resin (P), and the resin (P) may be used as the hydrophobic resin. As the hydrophobic resin, the same resin as that preferably contained in the composition for forming an upper layer can be used. The hydrophobic resin is preferably designed to be present on the surface of the sensitized ray-sensitive or radiation-sensitive film, and unlike the surfactant, it does not necessarily have to have a hydrophilic group in the molecule, and may not contribute to the polar substance. / Non-polar substances are mixed evenly. Examples of the effect of adding the hydrophobic resin include controlling the sensitizing ray property or the static/dynamic contact angle of the surface of the radiation-sensitive film to water, and suppressing out gas and the like.

The hydrophobic resin is preferably one or more of a "fluorine atom", a "deuterium atom", and a "CH ₃ partial structure contained in a side chain portion of the resin" from the viewpoint of being present in the surface layer of the film, and further preferably There are two or more types. Further, the hydrophobic resin preferably contains a hydrocarbon group having 5 or more carbon atoms. These groups may be contained in the main chain of the hydrophobic resin or may be substituted in the side chain.

When the hydrophobic resin contains a fluorine atom and/or a ruthenium atom, the fluorine atom and/or the ruthenium atom in the hydrophobic resin may be contained in the main chain of the resin or may be contained in the side chain.

In the case where the hydrophobic resin contains a fluorine atom, it is preferably a resin containing 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 by a fluorine atom, and may further have a substitution other than a fluorine atom. base. The cycloalkyl group having a fluorine atom is a monocyclic or polycyclic cycloalkyl group in which at least one hydrogen atom is substituted by a fluorine atom, and may further have a substituent other than a fluorine atom. The aryl group having a fluorine atom may be one 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 a substituent other than a fluorine atom. Examples of the repeating unit having a fluorine atom or a ruthenium atom are exemplified in paragraph 0519 of US2012/0251948A1.

Further, as described above, the hydrophobic resin preferably further contains a CH ₃ moiety structure in the side chain portion. Here, the structure of the side chain portion ₃ partially hydrophobic resin has CH, the partial structure containing ₃ ethyl, propyl and the like has CH. On the other hand, a methyl group directly bonded to a main chain of a hydrophobic resin (for example, an α-methyl group having a repeating unit of a methacrylic acid structure) is present on the surface due to the influence of the main chain on the hydrophobic resin. The help is small and thus is considered to be not included in the CH ₃ partial structure in the present invention.

For the hydrophobic resin, the descriptions of [0348] to [0415] of JP-A-2014-010245 can be incorporated into the specification of the present application.

In addition, the hydrophobic resin described in Japanese Laid-Open Patent Publication No. 2011-248019, the Japanese Patent Publication No. 2010-175859, and the Japanese Patent Publication No. 2012-032544 can be preferably used. Resin.

As the hydrophobic resin, a resin having the following structure can also be used.

[化75]

When the resist composition contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01% by mass to 10% by mass, and more preferably 0.05% by mass to 8% by mass based on the total solid content of the resist composition. quality%.

(Surfactant) The resist composition may further contain a surfactant. By using a surfactant, when an exposure light source having a wavelength of 250 nm or less, particularly 220 nm or less is used, a pattern having good sensitivity and resolution, good adhesion, and less development defects can be formed. As the surfactant, it is particularly preferred to use a fluorine-based and/or a lanthanoid surfactant. Examples of the fluorine-based and/or lanthanoid surfactants include the surfactants described in [0276] of the specification of U.S. Patent Application Publication No. 2008/0248425. Also available: Eftop EF301 or Eftop EF303 (made by New Akita Chemicals Co., Ltd.); Fluorad FC430, Fluorad 431 or Frode ( Fluorad) 4430 (manufactured by Sumitomo 3M); Megafac F171, Megafac F173, Megafac F176, Megafac F189, Megafac F113, Meijiafa ( Megafac) F110, Megafac F177, Megafac F120 or Megafac R08 (made by Diane Health (DIC)); Surflon S-382, Sha Fulong ( Surflon) SC101, Surflon 102, Surflon 103, Surflon 104, Surflon 105 or Surflon 106 (made by Asahi Glass) ; Troysol S-366 (manufactured by Troy Chemical); GF-300 or GF-150 (manufactured by East Asian Synthetic Chemicals Co., Ltd.); Surflon S-393 ( Seimi Chemical (manufactured by Seiko Chemical); Eftop EF121, Eftop EF122A, Eftop EF122B, Eftop RF122C, Eftop EF125M, Eftop EF135M, Eftop EF351 , Eftop EF352, Eftop EF801, Eftop EF802 or Eftop EF601 (made by Mitsubishi Materials Electronics Co., Ltd.); PF636, PF656, PF6320 or PF6520 (manufactured by OMNOVA); or FTX-204G, 208G, 218G, 230G, 204D, 208D, 212D, 218D or 222D (manufactured by Neos). Further, a polyoxyalkylene polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a lanthanoid surfactant.

Further, in addition to the known surfactants as described above, the surfactant may also be used by a short-chain polymerization method (also referred to as a short-chain polymer method) or an oligomerization method (also referred to as an oligomer method). The produced fluoroaliphatic compound is synthesized. Specifically, a polymer having a fluoroaliphatic group derived from the fluoroaliphatic compound can also be used as a surfactant. The fluoroaliphatic compound can be synthesized, for example, by the method described in JP-A-2002-90991. Further, a surfactant other than the fluorine-based and/or lanthanide-based surfactants described in [0280] of the specification of the US Patent Application Publication No. 2008/0248425 can also be used.

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

The content of the surfactant is preferably from 0% by mass to 2% by mass, more preferably from 0.0001% by mass to 2% by mass, even more preferably from 0.0005% by mass to 1% by mass based on the total solid content of the resist composition. .

(Other Additives) The resist composition may further contain a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorbing agent, and/or a compound which promotes solubility in a developing solution (for example, a molecular weight of 1,000 or less) a phenolic compound or an alicyclic compound or an aliphatic compound containing a carboxyl group).

The resist composition may further comprise a dissolution inhibiting compound. Here, the "dissolution inhibiting compound" means a compound having a molecular weight of 3,000 or less which is decomposed by the action of an acid and which has a reduced solubility in an organic developing solution.

(G) Cerium carboxylate The resist composition may also contain (G) a phosphonium carboxylate salt. Examples of the cerium carboxylate salt include a cerium carboxylate salt, a carboxylic acid sulfonium salt, and a carboxylate ammonium salt. In particular, as the (G) cerium carboxylate salt, a phosphonium salt or a phosphonium salt is preferred. Further, it is preferred that the carboxylate residue of the (G) cerium carboxylate salt does not contain an aromatic group or a carbon-carbon double bond. The particularly preferred anion moiety is preferably a linear, branched, monocyclic or polycyclic cyclic alkylcarboxylate anion having 1 to 30 carbon atoms. Further, it is preferably an anion of a part or all of the fluorine-substituted carboxylic acid of the alkyl group. An oxygen atom may also be included in the alkyl chain. Thereby, transparency to light of 220 nm or less is ensured, sensitivity and resolution are improved, and density and exposure margin are improved.

Examples of the anion of the fluorine-substituted carboxylic acid include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, perfluorododecanoic acid, and perfluorotridecanoic acid. Perfluorocyclohexanecarboxylic acid, anion of 2,2-bis-trifluoromethylpropionic acid, and the like.

The (G) cerium carboxylate salts can be synthesized by reacting cerium hydroxide, cerium hydroxide, ammonium hydroxide and a carboxylic acid with silver oxide in a suitable solvent.

The content of the (G) cerium carboxylate salt in the composition is usually 0.1% by mass to 20% by mass, preferably 0.5% by mass to 10% by mass, based on the total solid content of the resist composition, and further preferably 1%. Mass% to 7 mass%.

<Resist film> The present invention also relates to a resist film formed of the resist composition of the present invention. In order to form a resist film on a substrate by using a resist composition, it is preferred to dissolve each component in a solvent to prepare a resist composition, which is filtered by a filter as needed, and then applied onto a substrate. The filter is preferably a filter made of polytetrafluoroethylene, polyethylene or nylon having a pore diameter of 0.1 μm or less, more preferably 0.05 μm or less, and still more preferably 0.03 μm or less.

It is preferable to apply the resist composition to a substrate (for example, ruthenium or ruthenium dioxide coated) used for the production of a precision integrated circuit element. The method of applying the resist composition on the substrate can be applied to the substrate by a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, blade coating, etc., but is preferably used. For spin coating, the rotation speed is preferably from 1000 rpm to 3000 rpm. Various base films (inorganic film, organic film, anti-reflection film) may be formed in the lower layer of the resist film as needed. Further, it is preferred to dry the resist film before the formation of the upper film. Thereby, a film from which an unnecessary residual solvent is removed can be uniformly formed.

As the drying method, a method of heating (prebaking) and drying is usually used. The heating can be performed by a mechanism provided in a general exposure/developer, or by using a heating plate or the like. The heating temperature is not particularly limited, but it is preferably heated at 60 ° C to 150 ° C for 1 minute to 20 minutes, and more preferably at 80 ° C to 120 ° C for 1 minute to 15 minutes.

The film thickness of the resist film is preferably 0.02 μm to 0.5 μm, more preferably 0.02 μm to 0.3 μm, still more preferably 0.02 μm to 0.2 μm, and is resistant to the properties of the resist such as dry etching resistance. The thickness of the etchant film can be appropriately adjusted. The film thickness is preferably thick for the purpose of improving dry etching resistance, and is preferably 0.05 μm to 0.3 μm.

[Pattern forming method] The pattern forming method of the present invention is preferably a pattern forming method comprising the steps of: (a) forming a resist film from a resist composition, (c) by actinic ray or radiation pair a step of exposing the resist film, and (d) a step of developing the exposed resist film with a developing solution, using the present invention as a resist composition of the step (a) Resist composition. Further, a step of forming an upper layer film from the composition for forming an upper layer film on the resist film may be further included between the step (a) and the step (c).

<Step (a)> The step (a) of the pattern forming method of the present invention is a step of forming a resist film from the resist composition, preferably by forming a resist composition on the substrate. The step of etching the film.

<Step (b)> The step (b) of the pattern forming method of the present invention is a step of forming an upper layer film on the resist film from the composition for forming an upper layer film. In the step (b), it is preferred to apply the composition for forming an upper layer film (also referred to as "top coat composition") on the resist film formed in the step (a), and then heat it as needed (hereinafter) Pre-bake (PB; Prebake), thereby forming an upper film (also referred to as "top coat").

[Composition for forming an upper layer film] The composition for forming an upper layer film used in the pattern forming method of the present invention will be described. The top coat layer is preferably not mixed with the resist film, and further uniformly applied to the upper layer of the resist film. The top coat layer is not particularly limited, and a previously known top coat layer can be formed by a conventionally known method. For example, the top coat can be formed based on the description of paragraphs 0072 to 0082 of JP-A-2014-059543. Floor. For example, it is preferable to form a top coat layer containing a basic compound as described in Japanese Laid-Open Patent Publication No. 2013-61648 on the resist film. Specific examples of the basic compound which the top coat layer may contain are the same as the basic compound in the resist composition. Further, the top coat layer preferably contains a compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond, and an ester bond.

Further, the top coat layer preferably contains a resin. The resin which can be contained in the top coat layer is not particularly limited, and the same resin as the hydrophobic resin which can be contained in the resist composition can be used. For the hydrophobic resin, refer to [0017] to [0023] of the Japanese Patent Laid-Open Publication No. 2013-61647 (corresponding to [0017] to [0023] of US Published Patent Publication No. 2013/244438), and Japanese Patent Laid-Open The contents of [0016] to [0165] of the Japanese Patent Publication No. 2014-56194 are incorporated herein by reference. The top coat layer preferably contains a resin containing a repeating unit having an aromatic ring. By containing a repeating unit having an aromatic ring, particularly when exposed to an electron beam or EUV, the efficiency of generating secondary electrons and the acid generating efficiency of a compound derived from an acid generated by actinic rays or radiation become high. When forming, the effect of high sensitivity and high resolution can be expected. In the case of use in ArF immersion exposure, the resin preferably has substantially no aromatic group from the viewpoint of transparency of ArF light.

The weight average molecular weight of the resin is preferably from 3,000 to 100,000, more preferably from 3,000 to 30,000, most preferably from 5,000 to 20,000. In the total solid content, the amount of the resin in the top coat layer-forming composition is preferably 50% by mass to 99.9% by mass, more preferably 70% by mass to 99.7% by mass, and still more preferably 80% by mass to 99.5% by mass. %.

In the case where the top coat layer contains a plurality of resins, it is preferred to contain at least one resin (XA) having a fluorine atom and/or a ruthenium atom. More preferably, the top coat composition contains at least one of a resin (XA) having a fluorine atom and/or a ruthenium atom, and a resin (XB) having a fluorine atom and/or a ruthenium atom content lower than that of the resin (XA). Thereby, when the top coating film is formed, since the resin (XA) is biased on the surface of the top coating film, performance such as development characteristics or immersion liquid followability can be improved.

The content of the resin (XA) is preferably from 0.01% by mass to 30% by mass, more preferably from 0.1% by mass to 10% by mass, even more preferably 0.1% by mass based on the total solid content contained in the top coat composition. ～8% by mass, particularly preferably 0.1% by mass to 5% by mass. The content of the resin (XB) is preferably from 50.0% by mass to 99.9% by mass, more preferably from 60% by mass to 99.9% by mass, even more preferably 70% by mass based on the total solid content contained in the top coat composition. ～99.9% by mass, particularly preferably 80% by mass to 99.9% by mass.

The preferred range of the fluorine atom contained in the resin (XA) is preferably from 5% by mass to 80% by mass, and more preferably from 10% by mass to 80% by mass based on the weight average molecular weight of the resin (XA). The preferred range of the ruthenium atom contained in the resin (XA) is preferably from 2% by mass to 50% by mass, and more preferably from 2% by mass to 30% by mass based on the weight average molecular weight of the resin (XA).

The resin (XB) is preferably one which does not substantially contain a fluorine atom or a ruthenium atom. In this case, specifically, it has a repeating unit having a fluorine atom and has a ruthenium with respect to all repeating units in the resin (XB). The total content of the repeating units of atoms is preferably from 0 mol% to 20 mol%, more preferably from 0 mol% to 10 mol%, further preferably from 0 mol% to 5 mol%, particularly preferably 0 mol% to 3 mol%, ideally 0 mol%, that is, does not contain a fluorine atom and a deuterium atom.

In the total solid content, the amount of the resin in the entire top coat composition is preferably from 50% by mass to 99.9% by mass, more preferably from 60% by mass to 99.0% by mass.

In addition, the top coat layer may also contain an acid generator and a crosslinking agent. Specific examples of these components and preferred are as described above.

Typically, the top coat is formed from a top coat forming composition. The top coat layer-forming composition is preferably prepared by dissolving each component in a solvent and filtering the filter. The filter is preferably a filter made of polytetrafluoroethylene, polyethylene or nylon having a pore diameter of 0.1 μm or less, more preferably 0.05 μm or less, and still more preferably 0.03 μm or less. Further, a plurality of filters may be used in series or in parallel. Alternatively, the composition may be subjected to multiple filtrations, and the step of performing multiple filtrations may be a cyclic filtration step. Further, the composition may be subjected to a degassing treatment or the like before and after the filter is filtered. The top coat layer-forming composition of the present invention preferably does not contain impurities such as metals. The content of the metal component contained in the materials is preferably 10 ppm or less, more preferably 5 ppm or less, still more preferably 1 ppm or less, and particularly preferably not included (below the detection limit of the measuring device) ).

When the exposure described later is a liquid immersion exposure, the top coat layer also functions as a layer disposed between the resist film and the immersion liquid and not directly contacting the etchant with the resist film. In this case, the properties preferable for the top coat layer (the composition for forming a top coat layer) are coating suitability to a resist film, transparency to radiation, especially 193 nm, and impregnation liquid. Insoluble (preferably water). Further, the top coat layer is preferably not mixed with the resist film, and further uniformly applied to the surface of the resist film. Further, in order to apply the top coat layer-forming composition uniformly to the surface of the resist film without dissolving the resist film, the top coat layer-forming composition preferably contains an insoluble resist film. Solvent. As the solvent which does not dissolve the resist film, a solvent which is a component different from the developer (organic developer) containing an organic solvent is preferably used.

The coating method of the top coat layer forming composition is not particularly limited, and a conventionally known spin coating method, spray method, roll coating method, dipping method, or the like can be used.

The film thickness of the top coat layer is not particularly limited, and is usually from 5 nm to 300 nm, preferably from 10 nm to 300 nm, more preferably from 20 nm to 200 nm, from the viewpoint of transparency of the exposure light source. It is preferably formed in a thickness of 30 nm to 100 nm. After forming the top coat, the substrate is heated (PB) as needed. From the standpoint of analyticity, the refractive index of the top coat layer is preferably close to the refractive index of the resist film. The top coat layer is preferably insoluble in the immersion liquid, more preferably insoluble in water. Regarding the receding contact angle of the top coat layer, from the viewpoint of the followability of the immersion liquid, the receding contact angle (23 ° C) of the immersion liquid to the top coat layer is preferably from 50 to 100 degrees, more preferably from 80 to 100 degrees. . In the immersion exposure, the immersion liquid is required to follow the action of scanning the exposure head on the wafer at a high speed to form an exposure pattern, so that the contact angle of the immersion liquid to the top coating layer in the dynamic state becomes Importantly, in order to obtain better resist properties, it is preferred to have a receding contact angle of the stated range.

When the top coat is peeled off, an organic developer may be used, or a release agent may be separately used. As the release agent, a solvent having a small penetration into the resist film is preferred. From the viewpoint of simultaneously performing the peeling of the top coat layer and the development of the resist film, the top coat layer is preferably peeled off by the organic developer. The organic developing solution used for the peeling is not particularly limited as long as it can dissolve and dissolve the low-exposure portion of the resist film.

The dissolution rate of the top coat layer to the organic developer is preferably from 1 nm/sec to 300 nm/sec, more preferably from 10 nm/sec to 100 nm/sec, from the viewpoint of peeling off the organic developer. . Here, the dissolution rate of the top coat layer to the organic developer liquid refers to the film thickness reduction rate when the top coat layer is formed after exposure to the developer, and is immersed in butyl acetate at 23 ° C in the present invention. The speed of time. By setting the dissolution rate of the top coat layer to the organic developer to 1/sec second or more, preferably 10 nm/sec or more, the effect of reducing development defects after development of the resist film is reduced. In addition, by setting it to 300 nm/sec or less, preferably 100 nm/sec, there is a possibility that the line edge roughness of the pattern after developing the resist film may be affected by the decrease in exposure unevenness during immersion exposure. Further good results. The top coat layer can also be removed using other known developing solutions such as an alkaline aqueous solution. Specific examples of the alkaline aqueous solution that can be used include an aqueous solution of tetramethylammonium hydroxide.

The step of applying a pre-wetting solvent on the resist film may also be included between the steps (a) and (b). Thereby, the coatability of the composition for forming an upper layer film can be improved, and liquefaction can be achieved. The pre-wetting solvent is not particularly limited as long as it is a solvent having low solubility in the sensitizing ray-sensitive or radiation-sensitive film, and may be selected from the group consisting of an alcohol solvent, a fluorine solvent, an ether solvent, a hydrocarbon solvent, and an ester. A pre-wetting solvent for an upper layer film of one or more compounds in a solvent.

These solvents may be used alone or in combination of two or more. By mixing the solvent other than the above, the solubility in the resist film, the solubility of the resin in the composition for forming an upper layer film, the elution property from the resist film, and the like can be appropriately adjusted.

<Step (c)> The step (c) of the pattern forming method of the present invention is a step of exposing the resist film, and can be carried out, for example, by the following method. The resist film formed as described above is irradiated with actinic rays or radiation through a predetermined mask. Further, in the irradiation of the electron beam, it is usually a drawing (direct drawing) that does not interfere with the mask. The actinic ray or radiation is not particularly limited, and is, for example, a KrF excimer laser, an ArF excimer laser, an extreme ultraviolet (EUV light, Extreme Ultra Violet), an electron beam (EB), or the like. Extreme ultraviolet or electron beam. The exposure can be immersion exposure.

<Post Exposure Bake> In the pattern forming method of the present invention, it is preferred to perform baking (heating) after exposure and before development. The reaction of the exposed portion is promoted by baking, and the sensitivity or pattern shape is further improved. The heating temperature is not particularly limited as long as a favorable pattern can be obtained, and is usually 40 to 160 °C. The number of times PEB can be performed can be one time or multiple times. The heating time is preferably from 30 seconds to 1,000 seconds, more preferably from 60 seconds to 800 seconds, and still more preferably from 60 seconds to 600 seconds. The heating can be carried out by a mechanism provided in a usual exposure/developer, or by using a hot plate or the like.

<Step (d)> The step (d) of the pattern forming method of the present invention is a step of developing the exposed resist film with a developing solution containing an organic solvent.

<Developing Solution> The developing solution used in the developing step (d) is preferably an alkaline developing solution or a developing solution containing an organic solvent. The developer containing an organic solvent may also be referred to as an organic developer.

(Alkali developer) As the alkaline developer, for example, an inorganic base such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate, sodium metasilicate or ammonia, or a primary amine such as ethylamine or n-propylamine can be used. , secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide and hydrogen Tetraethylammonium oxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetraammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, ethyltrimethylammonium hydroxide, hydrogen Tetraalkylammonium hydroxide such as butyl trimethylammonium oxide, methyltributylammonium hydroxide or dibutyldipentylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, hydrogen An alkaline aqueous solution such as a quaternary ammonium salt such as trimethylphenylammonium hydroxide, trimethylbenzylammonium hydroxide or triethylbenzylammonium hydroxide; or a cyclic amine such as pyrrole or piperidine. Further, an appropriate amount of an alcohol or a surfactant may be added to the alkaline aqueous solution to be used. The alkali concentration of the alkaline developer is usually from 0.1% by mass to 20% by mass. The pH of the alkaline developer is usually from 10.0 to 15.0. As the alkaline developing solution, an aqueous solution of 2.38 mass% of tetramethylammonium hydroxide is particularly preferable.

(Organic Developing Solution) Next, the organic solvent contained in the organic developing solution will be described. The vapor pressure of the organic solvent (in the case of a mixed solvent, the overall vapor pressure) is preferably 5 kPa or less at 20 ° C, more preferably 3 kPa or less, and particularly preferably 2 kPa or less. When the vapor pressure of the organic solvent is 5 kPa or less, the evaporation of the developer onto the substrate or in the developing cup is suppressed, and the temperature uniformity in the wafer surface is improved, and as a result, the dimensional uniformity in the wafer surface is improved. Various organic solvents can be widely used as the organic solvent to be used in the organic developing solution. For example, an ester solvent, a ketone solvent, an alcohol solvent, a guanamine solvent, an ether solvent, or a hydrocarbon solvent can be used.

The ester solvent refers to a solvent having an ester bond in the molecule, and the ketone solvent refers to a solvent having a ketone group in the molecule, and the alcohol solvent refers to a solvent having an alcoholic hydroxyl group in the molecule, and the amide solvent is a solvent. A solvent having a guanamine group in the molecule, and the ether solvent means a solvent having an ether bond in the molecule. In these cases, a solvent having a plurality of such functional groups in one molecule is also present, but in this case, it corresponds to any solvent type including a functional group of the solvent. For example, diethylene glycol monomethyl ether corresponds to any of an alcohol solvent and an ether solvent in the classification. Further, the hydrocarbon solvent means a hydrocarbon solvent which does not have a substituent. In particular, an organic developer containing at least one solvent selected from the group consisting of an ester solvent, a ketone solvent, an ether solvent, and a hydrocarbon solvent is preferred, and an organic developer containing an ester solvent is more preferred.

Examples of the ester solvent include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, propyl acetate, isopropyl acetate, and amyl acetate. (pentyl acetate), isoamyl acetate (isopentyl acetate, 3-methylbutyl acetate), 2-methylbutyl acetate, 1-methyl acetate Butyl ester, hexyl acetate, heptyl acetate, octyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, butyl butyrate, methyl 2-hydroxyisobutyrate, propylene glycol monomethyl ether acetate (PGMEA (propylene glycol monomethyl ether acetate); alias 1-methoxy-2-ethoxypropane propane), ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl Ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol Alcohol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate , 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl Acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxy butyl Acid ester, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetic acid Ester, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, Propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate , ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, C Amyl oleate, hexyl propionate, heptyl propionate, butyl butyrate, isobutyl butyrate, amyl butyrate, hexyl butyrate, isobutyl isobutyrate , propyl valerate, isopropyl valerate, butyl valerate, amyl valerate, ethyl hexanoate, propyl hexanoate, butyl hexanoate, isobutyl hexanoate, methyl heptanoate, heptanoic acid Ethyl ester, propyl heptanoate, cyclohexyl acetate, cycloheptyl acetate, 2-ethylhexyl acetate, cyclopentyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, and the like. Among these, butyl acetate, amyl acetate, isoamyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, amyl propionate, propionic acid can be preferably used. Ester isoamyl acetate can be particularly preferably used as the ester, the heptyl propionate and the butyl butyrate.

Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, and 2-hexanone. Diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetyl ketone, acetonyl acetone, ionone, diacetone alcohol And acetonitrile, acetophenone, methylnaphthyl ketone, isophorone, propyl carbonate, γ-butyrolactone, etc., of which 2-heptanone is preferred.

Examples of the alcohol-based solvent include methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, 3-methyl-1-butanol, and tert-butyl alcohol. Pentanol, 2-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3- Heptanol, 3-octanol, 4-octanol, 3-methyl-3-pentanol, cyclopentanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-2- Butanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-2- Pentanol, 4-methyl-3-pentanol, cyclohexanol, 5-methyl-2-hexanol, 4-methyl-2-hexanol, 4,5-dimethyl-2-hexanol, 4-methyl-2-heptanol, 6-methyl-2-heptanol, 7-methyl-2-octanol, 8-methyl-2-nonanol, 9-methyl-2-nonanol, An alcohol such as 3-methoxy-1-butanol (monohydric alcohol); or a glycol solvent such as ethylene glycol, diethylene glycol or triethylene glycol; or ethylene glycol monomethyl ether or propylene glycol monomethyl ether ( PGME (propylene glycol monomethyl ether); alias 1-methoxy-2-propanol), diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxy methyl butanol, ethylene glycol monoethyl ether, Ethylene glycol monopropyl A glycol-containing solvent such as ether, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether or propylene glycol monophenyl ether. Among these, a glycol ether solvent is preferably used.

Examples of the ether solvent include, in addition to the glycol ether solvent containing a hydroxyl group, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethyl ether. a glycol ether-free solvent such as diol diethyl ether; an aromatic ether solvent such as anisole or phenethyl ether; dioxane, tetrahydrofuran, tetrahydropyran, perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran , 1,4-dioxane, and the like. Further, examples thereof include cyclopentyl isopropyl ether, cyclopentyl second butyl ether, cyclopentyl third butyl ether, cyclohexyl isopropyl ether, cyclohexyl second butyl ether, and cyclohexyl third butyl ether. a branched aliphatic alkyl ether solvent; or a non-cyclic aliphatic ether solvent having a linear alkyl group such as di-n-propyl ether, di-n-butyl ether, di-n-pentyl ether or di-n-hexyl ether Or diisohexyl ether, methyl isoamyl ether, ethyl isoamyl ether, propyl isoamyl ether, diisoamyl ether, methyl isobutyl ether, ethyl isobutyl ether, propyl isobutyl ether, diisobutyl An acyclic aliphatic ether solvent having a branched alkyl group such as ether, diisopropyl ether, ethyl isopropyl ether or methyl isopropyl ether. Among them, from the viewpoint of in-plane uniformity of the wafer, an acyclic aliphatic ether solvent having 8 to 12 carbon atoms is preferable, and an acyclic compound having a branched alkyl group having 8 to 12 carbon atoms is more preferable. An aliphatic ether solvent. Particularly preferred is diisobutyl ether, diisoamyl ether or diisohexyl ether.

As the amide-based solvent, for example, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphonium triamine can be used. , 1,3-dimethyl-2-imidazolidinone, and the like.

Examples of the hydrocarbon-based solvent include pentane, hexane, octane, decane, decane, dodecane, undecane, hexadecane, 2,2,4-trimethylpentane, and 2, An aliphatic hydrocarbon solvent such as 2,3-trimethylhexane, perfluorohexane or perfluoroheptane; toluene, xylene, ethylbenzene, propylbenzene, 1-methylpropylbenzene, 2-methyl An aromatic hydrocarbon solvent such as propyl benzene, dimethyl benzene, diethyl benzene, ethyl methyl benzene, trimethyl benzene, ethyl dimethyl benzene or dipropyl benzene; octene, decene, An unsaturated hydrocarbon solvent such as terpene, undecene, dodecene or hexadecene. The unsaturated hydrocarbon solvent may have a plurality of double bonds and triple bonds, and may be present at any position of the hydrocarbon chain. A cis or trans body having a double bond can also be mixed. Further, the hydrocarbon solvent may be a mixture of compounds having the same carbon number and different structures. For example, when decane is used as the aliphatic hydrocarbon-based solvent, 2-methyl decane, 2,2-dimethyloctane, 4-ethyl octane, which are compounds having the same carbon number and different structures, Isodecane or the like may also be contained in the aliphatic hydrocarbon-based solvent. In addition, the compound having the same carbon number and different structure may include only one type, and may also contain a plurality of types as described.

In the case where EUV light and EB are used in the exposure step, the organic solvent contained in the organic developer can be used to suppress swelling of the resist film, and it is preferred to use carbon atoms. An ester solvent having 7 or more (preferably 7 to 14, more preferably 7 to 12, more preferably 7 to 10) and having 2 or less hetero atoms. The hetero atom of the ester solvent is an atom other than a carbon atom or a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, and a sulfur atom. The number of hetero atoms is preferably 2 or less.

Preferable examples of the ester solvent having 7 or more carbon atoms and 2 or less hetero atoms include amyl acetate, isoamyl acetate, 2-methylbutyl acetate, and 1-methylbutyl acetate. Hexyl acetate, amyl propionate, hexyl propionate, butyl propionate, isobutyl isobutyrate, heptyl propionate, butyl butyrate, etc., particularly preferably isoamyl acetate.

In the organic solvent contained in the organic-based developer, when EUV light and EB are used in the exposure step, a mixed solvent of the ester solvent and the hydrocarbon solvent or the ketone may be used. A solvent mixture of the solvent and the hydrocarbon solvent is used instead of the ester solvent having 7 or more carbon atoms and 2 or less hetero atoms. In this case, the suppression of the swelling of the resist film is also effective. When an ester solvent is used in combination with a hydrocarbon solvent, it is preferred to use isoamyl acetate as the ester solvent. Further, from the viewpoint of the solubility of the resist film, it is preferred to use a saturated hydrocarbon solvent (for example, octane, decane, decane, dodecane, undecane, hexadecane, etc.). ). When a ketone solvent is used in combination with a hydrocarbon solvent, 2-heptanone is preferably used as the ketone solvent. Further, from the viewpoint of the solubility of the resist film, it is preferred to use a saturated hydrocarbon solvent (for example, octane, decane, decane, dodecane, undecane, hexadecane, etc.). ). In the case of using the mixed solvent, the content of the hydrocarbon-based solvent is not particularly limited as long as it depends on the solvent solubility of the resist film, and may be appropriately prepared and determined as necessary.

The organic solvent may be mixed in a plurality of types, or may be used in combination with a solvent or water other than the above. In order to fully exhibit the effects of the present invention, it is preferred that the entire water content of the developer is less than 10% by mass, and more preferably, it does not substantially contain water. The concentration of the organic solvent in the developer (total in the case of mixing a plurality of kinds) is preferably 50% by mass or more, more preferably 50% by mass to 100% by mass, still more preferably 85% by mass to 100% by mass, and further more preferably It is preferably from 90% by mass to 100% by mass, particularly preferably from 95% by mass to 100% by mass. The best is the case where only the organic solvent is substantially contained. Further, in the case where the organic solvent is substantially contained, a case where a trace amount of a surfactant, an antioxidant, a stabilizer, an antifoaming agent, or the like is contained may be contained.

The developer is also preferably containing an antioxidant. Thereby, the generation of the oxidizing agent over time can be suppressed, and the content of the oxidizing agent can be further reduced. As the antioxidant, a known one can be used, and when it is used for a semiconductor application, an amine-based antioxidant or a phenol-based antioxidant can be preferably used.

The content of the antioxidant is not particularly limited, and is preferably 0.0001% by mass to 1% by mass, more preferably 0.0001% by mass to 0.1% by mass, even more preferably 0.0001% by mass to 0.01% by mass, based on the total mass of the developer. When it is 0.0001% by mass or more, a more excellent oxidation resistance effect can be obtained, and when it is 1% by mass or less, the development residue tends to be suppressed.

The developer may contain a basic compound, and specific examples thereof include the same basic compound as the basic compound which may be contained in the resist composition.

The developer may also contain a surfactant. When the developer contains a surfactant, the wettability of the resist film is improved, and development proceeds more efficiently. As the surfactant, the same surfactant as that which can be contained in the resist composition can be used. When the developer contains a surfactant, the content of the surfactant is preferably 0.001% by mass to 5% by mass, more preferably 0.005% by mass to 2% by mass, even more preferably 0.01% based on the total mass of the developer. Mass% to 0.5% by mass.

As a developing method, for example, a method of immersing a substrate in a tank filled with a developing solution for a certain period of time (dipping method), and a method of developing the developing solution on the surface of the substrate and standing still for a certain period of time by surface tension can be applied. (liquid coating method); a method of spraying a developer on a surface of a substrate (spray method); a method of continuously ejecting a developer onto a substrate rotating at a constant speed while scanning a developer discharge nozzle at a constant speed (dynamic dispensing method) Wait. Further, after the step of developing, the step of stopping the development while replacing the other solvent may be carried out. The development time is not particularly limited and is usually from 10 seconds to 300 seconds, preferably from 20 seconds to 120 seconds. The temperature of the developer is preferably from 0 ° C to 50 ° C, more preferably from 15 ° C to 35 ° C.

Regarding the developing solution used in the developing step, both development using a developing solution containing an organic solvent and development using an alkaline developing solution can be performed (so-called double development can be performed).

<Step (e)> The pattern forming method of the present invention preferably includes the step (e) of rinsing (cleaning) the developed resist film with the eluent after the step (d).

<Eluent> As the eluent in the rinsing treatment after alkali development, pure water may be used, and an appropriate amount of a surfactant may be added and used. Further, after the development treatment or the rinsing treatment, the treatment for removing the developer or eluent adhering to the pattern by the supercritical fluid may be performed.

As the eluent in the rinsing treatment after development of the organic solvent, it is preferred to use an eluent (organic eluent) containing an organic solvent.

The vapor pressure of the eluent (in the case of a mixed solvent, the overall vapor pressure) 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 eluent to 0.05 kPa or more and 5 kPa or less, the temperature uniformity in the wafer surface is improved, and the swelling due to the penetration of the eluent is suppressed, and the wafer surface is uniform in size. Sex has changed.

(Organic solvent) Various organic solvents can be used as the organic solvent contained in the organic eluent, and it is preferred to use a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, or a guanamine system. At least one organic solvent in the group consisting of a solvent and an ether solvent. It is particularly preferred that the eluent contains a hydrocarbon solvent. Specific examples of the organic solvents are the same as those described in the developer.

In the case where EUV light or EB is used in the exposure step in the organic solvent contained in the organic eluent, it is preferred to use a hydrocarbon solvent, more preferably an aliphatic hydrocarbon, in the organic solvent. Is a solvent. The aliphatic hydrocarbon solvent used in the eluent is preferably an aliphatic hydrocarbon solvent having a carbon number of 5 or more from the viewpoint of further improving the effect (for example, pentane, hexane, octane, hydrazine). The alkane, undecane, dodecane, hexadecane or the like is preferably an aliphatic hydrocarbon solvent having 8 or more carbon atoms, more preferably an aliphatic hydrocarbon solvent having 10 or more carbon atoms. In addition, the upper limit of the number of carbon atoms of the aliphatic hydrocarbon-based solvent is not particularly limited, and is, for example, 16 or less, preferably 14 or less, and more preferably 12 or less. Among the aliphatic hydrocarbon-based solvents, particularly preferred are decane, undecane, and dodecane, and most preferably undecane. As described above, by using a hydrocarbon solvent (especially an aliphatic hydrocarbon solvent) as the organic solvent contained in the eluent, the developer slightly infiltrated into the resist film after development is washed to further suppress swelling. And the effect of suppressing the collapse of the pattern is further exerted. Further, examples of the hydrocarbon solvent include unsaturated hydrocarbon solvents such as octene, decene, decene, undecene, dodecene, and hexadecene. The unsaturated hydrocarbon solvent may have a plurality of double bonds and triple bonds, and may be present at any position of the hydrocarbon chain. A Cis body or a trans body having a double bond can also be mixed. Further, the hydrocarbon solvent may be a mixture of compounds having the same carbon number and different structures. For example, when decane is used as the aliphatic hydrocarbon-based solvent, 2-methyl decane, 2,2-dimethyloctane, 4-ethyl octane, which are compounds having the same carbon number and different structures, Isodecane or the like may also be contained in the aliphatic hydrocarbon-based solvent. In addition, the compound having the same carbon number and different structure may include only one type, and may also contain a plurality of types as described.

The organic solvent may be mixed in a plurality of types or may be used in combination with an organic solvent other than the above. The solvent may be mixed with water, but the water content in the eluent is usually 60% by mass or less, preferably 30% by mass or less, more preferably 10% by mass or less, and most preferably 5% by mass or less. By setting the water content to 60% by mass or less, good rinsing properties can be obtained.

The eluent preferably contains a surfactant. Thereby, there is a tendency that the wettability of the resist film is improved and the cleaning effect is further improved. As the surfactant, the same surfactant as that used in the resist composition can be used. The content of the surfactant is usually 0.001% by mass to 5% by mass, preferably 0.005% by mass to 2% by mass, and more preferably 0.01% by mass to 0.5% by mass based on the total mass of the eluent.

The eluent preferably contains an antioxidant. Thereby, the generation of the oxidizing agent over time can be suppressed, and the content of the oxidizing agent can be further reduced. Specific examples and contents of the antioxidant are as described in the developing solution.

In the elution step, the developed wafer is cleaned using the eluent. The method of the cleaning treatment is not particularly limited, and examples thereof include a method of continuously ejecting the eluent onto a substrate rotating at a constant speed (rotary coating method), and immersing the substrate in a tank filled with the eluent for a certain period of time. Method (dipping method); and method for spraying the eluent on the surface of the substrate (spray method). Preferably, the cleaning treatment is performed by a spin coating method, and then the substrate is rotated at a number of revolutions of 2000 rpm to 4000 rpm to remove the eluent from the substrate.

Usually, the developer and the eluent are stored in a waste liquid tank through a pipe after use. In this case, when a hydrocarbon-based solvent is used as the eluent, the resist dissolved in the developer is deposited, and in order to prevent adhesion to the back surface of the wafer or the side surface of the tube, the solvent for dissolving the resist is again present. The method of piping. The method of piping is a method of washing and washing the back surface or the side surface of the substrate with a solvent that dissolves the resist after washing with the eluent, or by dissolving the resist without contacting the resist. The method in which the solvent is rinsed by piping.

Various materials used in the resist composition of the present invention and the pattern forming method of the present invention (for example, a resist solvent, a developer, an eluent, an antireflection film-forming composition, and an upper film formation) The composition or the like) preferably contains no impurities such as a metal, a metal salt containing a halogen, an acid or a base (excluding a base in an alkaline developing solution). The content of the impurities contained in the materials is preferably 1 ppm or less, more preferably 1 ppb or less, still more preferably 100 ppt or less, particularly preferably 10 ppt or less, and most preferably substantially not contained (for The detection limit of the measuring device is below). As a method of removing impurities such as metals from various materials, for example, filtration using a filter or purification step by distillation (particularly, thin film distillation, molecular distillation, or the like) may be mentioned. For the purification step by distillation, for example, "<Factory Operation Series> Supplementary and Distillation, July 31, 1992, Chemical Industry Company" or "Chemical Engineering Handbook, September 30, 2004, Asakura Bookstore, 95 pages ~102 pages." As the filter pore diameter, the pore diameter is preferably 10 nm or less, more preferably 5 nm or less, and further preferably 3 nm or less. The material of the filter is preferably a filter made of polytetrafluoroethylene, polyethylene or nylon. The filter may also be a composite material in which these materials are combined with an ion exchange medium. The filter may also be used in advance by washing with an organic solvent. In the filter filtration step, a plurality of filters can be used in series or in parallel. When using a variety of filters, it is also possible to combine filters with different apertures and/or materials. In addition, various materials may be subjected to multiple filtrations, and the step of performing multiple filtrations may also be a cyclic filtration step. In addition, as a method of reducing impurities such as metals contained in various materials, a method of selecting a raw material having a small metal content as a raw material constituting each material, filtering a raw material constituting each material, and using Teflon ( Teflon) (registered trademark) Distillation or the like is carried out under conditions in which a liner or the like is formed in the apparatus to suppress contamination as much as possible. The preferred conditions for filter filtration of the raw materials constituting the various materials are the same as those described. In addition to filter filtration, adsorbent materials can also be used to remove impurities, and filter filters can be used in combination with adsorbent materials. As the adsorbent, a known adsorbent can be used. For example, an inorganic adsorbent such as cerium oxide gel or zeolite or an organic adsorbent such as activated carbon can be used.

<Storage container> When the developer and the eluent have an organic solvent, the organic solvent (organic treatment liquid) which can be used as the developer and the eluent is preferably used in a chemical having a storage portion. The patterning of the amplified resist film is carried out in a storage container for an organic treatment liquid. In the storage container, for example, a storage container for an organic processing liquid for patterning of a chemically amplified resist film is used, and an inner wall of the storage portion of the storage container that is in contact with the organic treatment liquid is A resin different from a polyethylene resin, a polypropylene resin, and a polyethylene-polypropylene resin, or a metal which is subjected to rust prevention/metal elution prevention treatment. A predetermined organic solvent used as the organic processing liquid for patterning of the chemically amplified resist film is stored in the storage portion of the storage container, and can be used for patterning the chemically amplified resist film. The storage portion is discharged.

In the case where the storage container further has a sealing portion for closing the storage portion, the sealing portion is preferably made of a resin different from a polyethylene resin, a polypropylene resin, and a polyethylene-polypropylene resin, or Metal formation with rust prevention and metal elution prevention treatment is performed. Here, the sealing portion refers to a member capable of blocking the accommodating portion and the outside air, and a gasket or an O-ring or the like is preferably used.

The resin different from the polyethylene resin, the polypropylene resin, and the polyethylene-polypropylene resin is preferably a perfluoro resin.

Examples of the perfluoro resin include tetrafluoroethylene resin (PTFE), tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer resin (FEP), and tetrafluoroethylene-ethylene. Copolymer resin (ETFE), chlorotrifluoroethylene-ethylene copolymer resin (ECTFE), vinylidene fluoride resin (PVDF), chlorotrifluoroethylene copolymer resin (PCTFE), fluoroethylene resin (PVF), and the like. Examples of the particularly preferred perfluororesin include a tetrafluoroethylene resin, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and a tetrafluoroethylene-hexafluoropropylene copolymer resin.

Examples of the metal in the metal which is subjected to the rust preventive/metal elution prevention treatment include carbon steel, alloy steel, nickel chrome steel, nickel chrome molybdenum steel, chrome steel, chrome molybdenum steel, and manganese steel. As the rust-preventing/metal elution prevention treatment, it is preferable to apply a film technique. The film technology is roughly classified into three types: metal coating (various plating), inorganic coating (various chemical conversion treatment, glass, concrete, ceramics, etc.) and organic coating (rustproof oil, paint, rubber, and plastic). As a preferable film technique, surface treatment using an rust preventive oil, a rust preventive, a corrosion inhibitor, a chelate compound, a peelable plastic, and an lining agent is mentioned. Among them, preferred are various chromate, nitrite, citrate, phosphate, oleic acid, dimer acid, naphthenic acid and the like, carboxylic acid metal soap, sulfonate, amine salt, ester ( Corrosion inhibitors such as glycerides or phosphates of higher fatty acids, chelation of ethyldiaminetetraacetic acid, gluconic acid, nitrogen triacetic acid, hydroxyethyl-ethylidene diamine triacetic acid, di-ethyltriamine pentaacetic acid, etc. Compound and fluororesin lining. Particularly preferred for phosphate treatment and fluororesin lining. Further, in comparison with the direct coating treatment, the treatment method in which the rust prevention period is extended by the coating treatment is not directly rust-proof, and it is preferable to use the "pre-treatment" as the pre-stage in connection with the rust-preventing treatment. As a specific example of such pretreatment, a treatment for removing various corrosion factors such as chloride or sulfate present on the surface of the metal by washing or polishing is preferably exemplified.

Specific examples of the storage container include the following. · Fluoro Pure PFA composite drum manufactured by Entegris (liquid inner surface: PFA resin lining) · Steel drum made by JFE (liquid inner surface: zinc phosphate film)

In addition, as a storage container which can be used in the present invention, Japanese Patent Laid-Open No. Hei 11-021393 (0013) to [0030], and Japanese Patent Laid-Open No. Hei 10-45961 [0012] to [0024] The container of the record.

In order to prevent malfunction of the liquid chemical pipe or various components (filter, O-ring, tube, etc.) due to electrostatic charging and subsequent electrostatic discharge, the organic processing liquid in the present invention may be added with a conductive compound. The conductive compound is not particularly limited, and examples thereof include methanol. The amount of addition is not particularly limited, and is preferably 10% by mass or less, and more preferably 5% by mass or less from the viewpoint of maintaining preferable development characteristics. As the member of the chemical liquid pipe, various pipes made of SUS (stainless steel) or a film made of polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, or the like) subjected to antistatic treatment can be used. As the filter or the O-ring, polyethylene, polypropylene, or a fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, or the like) to which antistatic treatment is applied can be similarly used.

The pattern obtained by the pattern forming method of the present invention can be preferably used as an etching mask for a semiconductor element or the like, and can be used for other purposes. For other uses, for example, guided pattern formation in Directed Self-Assembly (DSA) (for example, refer to "American Chemical Society Nano (ACS Nano)" (Vol. 4 No. 8 No. 4815) -4823)), the use of a core material (core) as a spacer process (for example, see Japanese Patent Laid-Open No. Hei 3-270227, Japanese Patent Laid-Open No. Hei No. 2013-164509, etc.).

<Blank Mask> Further, the present invention relates to a blank mask provided with the resist film of the present invention. In order to obtain such a blank mask having a resist film, when a pattern is formed on a blank mask for photomask production, a transparent substrate such as quartz or calcium fluoride may be used as the transparent substrate to be used. Usually, a light shielding film and an antireflection film are laminated on the substrate, and a phase shift film is laminated thereon, and an essential film of a functional film such as an etching stopper film or an etching mask film is added. As a material of the functional film, a film containing a transition metal such as ruthenium or chromium, molybdenum, zirconium, hafnium, tungsten, titanium or tantalum is laminated. In addition, as a material used for the outermost layer, a material containing oxygen and/or nitrogen in a crucible or a crucible may be exemplified as a main constituent material; and a material containing a transition metal in the above may be used as a main constituent material. a ruthenium compound material; or a transition metal, particularly one selected from the group consisting of chromium, molybdenum, zirconium, hafnium, tungsten, titanium, hafnium, etc., or further comprising one or more selected from the group consisting of oxygen, nitrogen, and carbon The material of the element is a transition metal compound material as a main constituent material. The light shielding film may be a single layer, but more preferably a multilayer structure in which a plurality of materials are coated in a plurality of layers. In the case of a multilayer structure, the thickness of the film of each layer is not particularly limited, and is preferably 5 nm to 100 nm, more preferably 10 nm to 80 nm. The thickness of the entire light shielding film is not particularly limited, but is preferably 5 nm to 200 nm, more preferably 10 nm to 150 nm.

[Manufacturing Method of Electronic Component] The present invention also relates to a method of manufacturing an electronic component including the pattern forming method of the present invention. The electronic component manufactured by the method of manufacturing an electronic component of the present invention can be preferably mounted in the manufacture of an electric and electronic device (a home appliance, an office appliance (OA), a media-related device, an optical device, a communication device, etc.). By. [Examples]

Hereinafter, the present invention will be described by way of examples, but the invention is not limited to the examples.

<Reference Synthesis Example 1: Synthesis of Compound M-1, Compound M-2> (Synthesis of Compound M-1) 2.10 g of 2-(dimethylamino)ethyl methacrylate (1) was dissolved in 21.0. To the dehydrated acetonitrile of g, 3.49 g of bromoacetic acid-t-butyl ester was added, and the mixture was stirred at 40 ° C for 24 hours under a nitrogen atmosphere. 100 g of ethyl acetate was added and the precipitated crystals were collected by filtration and dried to give 2.95 g of Compound (2). Further, 2.95 g of the compound (2) was subjected to hydrolysis with trifluoroacetic acid (TFA) to obtain 2.43 g of (M-1).

(Synthesis of Compound M-2) 200 g of p-ethoxylated styrene (3) was dissolved in 371 g of ethyl acetate, and 95.2 g of sodium methoxide (28% by mass methanol solution) was added at 0 ° C. Stir for 5 hours. After adding 200 g of a saturated aqueous solution of ammonium chloride at 0 ° C and stopping the reaction, 100 g of ethyl acetate was added, and the organic layer was washed twice with a saturated aqueous solution of 200 g of ammonium chloride, and 200 g of ion-exchanged water was used. The organic layer was washed twice, then dried over anhydrous magnesium sulfate, and the solvent was distilled off by about half to obtain 290 g of a 50.0 mass% ethyl acetate solution of p-hydroxystyrene (4). Then, 20.0 g of a 50.0% by mass ethyl acetate solution of the compound (4) was dissolved in 80 g of dehydrated dimethylformamide, cooled to 0 ° C, and 2.10 g of sodium hydride was added, and it was carried out under a nitrogen atmosphere. Stir. 8.86 g of 2-(dimethylamino)-1-chloroethane was added dropwise, and stirred at room temperature for 5 hours. After cooling to 0 ° C, the reaction was stopped with 80 g of ion-exchanged water, 200 g of ethyl acetate was added, and the organic layer was washed twice with 200 g of 1 N aqueous sodium hydroxide solution, and 200 g of ion-exchanged water was used. The organic layer was washed three times. The organic layer was recovered and the solvent was distilled away to give 7.96 g of Compound (5). Further, 5.50 g of the compound (5) was dissolved in 55 g of dehydrated acetonitrile, 7.85 g of bromoacetic acid-t-butyl ester was added, and the mixture was stirred at 40 ° C for 12 hours under a nitrogen atmosphere. 100 g of ethyl acetate was added to the reaction system, and the organic layer was washed four times with 200 g of ion-exchanged water. The organic layer was recovered and the solvent was distilled away to give 8.75 g of Compound (6A). Further, 8.75 g of (6A) was supplied to the hydrolysis using TFA to obtain 7.98 g of (M-2).

[化76]

<Synthesis Example 1: Synthesis of Resin P-20> A compound of (5), 50.0% by mass of a cyclohexanone solution, 7.05 g, 0.75 g of a compound (M-1), 5.97 g of a compound (6), and 0.33 g of The polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 14.75 g of PGME. 10.15 g of PGME was added to the reaction vessel, and the mixture was added dropwise over a period of 4 hours in a system of 85 ° C under a nitrogen atmosphere. After the reaction solution was continuously heated and stirred for 2 hours, it was left to cool to room temperature. The reaction solution was added dropwise to 600 g of heptane / ethyl acetate = 9 / 1 (mass ratio), and the polymer was precipitated and filtered. The filtered solid was washed with 200 g of heptane / ethyl acetate = 9 / 1 (mass ratio). Thereafter, the washed solid was dried under reduced pressure to obtain 7.70 g of a resin (P-20).

[化77]

The resin (P-1) to the resin (P-27) were synthesized in the same manner as the resin (P-20).

The obtained resin was measured by GPC (carrier: tetrahydrofuran (THF)) to calculate a weight average molecular weight (Mw: polystyrene), a number average molecular weight (Mn: polystyrene), and a degree of dispersion (Mw/Mn, The following "Pd"). Further, the composition ratio (Mohr ratio) was calculated by ¹ H-NMR (Nuclear Magnetic Resonance) measurement.

The composition of the synthesized resin and the composition ratio (mol ratio) of the repeating unit, the weight average molecular weight (Mw), and the degree of dispersion (Mw/Mn) are shown below.

[化78]

[化79]

[化80]

Hereinafter, the resin (PR-1) to the resin (PR-5) were synthesized in the same manner. The structure, composition ratio (mole ratio), weight average molecular weight, and dispersity of the separately synthesized resins are shown below.

[化81]

Hereinafter, the photoacid generator, the basic compound, the crosslinking agent, the hydrophobic resin, the surfactant, the solvent, the composition for forming an upper layer film, the developer, and the eluent used in the examples and the comparative examples are shown.

[Photoacid generator] The photoacid generator is appropriately selected from the specific compound (z1 to z35) and used.

[basic compound]

[化82]

[crosslinking agent]

[化83]

[hydrophobic resin]

[化84]

[Solvent] S-1: propylene glycol monomethyl ether acetate (PGMEA) (boiling point 146 ° C) S-2: propylene glycol monomethyl ether (PGME) (boiling point 120 ° C) S-3: ethyl lactate (boiling point 151 ° C) S-4: cyclohexanone (boiling point 157 ° C)

[Interfacial Agent] W-1: Megafac R08 (manufactured by Di Aisheng (DIC) Co., Ltd.; Fluorine and Lanthanide) W-2: Polyoxane polymer KP-341 (Shin-Etsu Chemical Industry Co., Ltd. ) Manufactured; lanthanide) W-3: Troysol S-366 (manufactured by Troy Chemical Co., Ltd.; fluorine system) W-4: PF6320 (manufactured by OMNOVA); system)

[Composition for the upper layer film] As a composition for the upper layer film, the components shown in the following Table 2 were dissolved in a solvent to prepare a solution having a solid concentration of 2.0% by mass, and a pore diameter of 0.04 μm was used. The polyethylene filter was filtered to prepare a composition for forming an upper layer film.

[化85]

[Table 1]

[化86]

[Table 2]

[developing solution and eluent] G-1: 2.38 mass% aqueous solution of tetramethylammonium hydroxide G-2: butyl acetate G-3: 3-methylbutyl acetate G-4: pure water G-5: Undecane G-6: diisobutyl ketone G-7: isobutyl isobutyrate G-8: methyl amyl ketone G-9: 4-methyl-2-heptanol G-10: diiso Butyl Ether G-11: Diisoamyl Ether G-12: Diisohexyl Ether G-13: Decane

[Example 1-A to Example 20-A, Comparative Example 1-AR to Comparative Example 4-AR (Electron Beam (EB) Exposure)] (1) Coating liquid preparation and coating of resist composition 0.1 The membrane filter having a pore size of μm was subjected to fine filtration of a coating liquid composition having a solid concentration of 2.5% by mass having a composition shown in Table 3 below to obtain a resist composition solution. The resist composition solution was applied to a 6-inch Si substrate previously treated with Hexamethyldisilazane (HMDS) using a spin coater Mark 8 manufactured by Tokyo Electron. The film was dried on a hot plate at 110 ° C for 90 seconds to obtain a resist film having a film thickness of 50 nm. With respect to Example 3-A and Example 8-A, the composition for forming an upper layer film shown in Table 3 was further applied onto a resist film. Thereafter, baking was continued at 110 ° C for 90 seconds to form an upper film having a film thickness of 50 nm. Here, 1吋 is 0.0254 m.

(2) EB exposure and development The wafer on which the resist film obtained in the above (1) was formed was subjected to pattern irradiation using an electron beam drawing device (HL750 manufactured by Hitachi, Ltd., acceleration voltage: 50 KeV). At this time, the drawing is performed in such a manner as to form a 1:1 line and space.

Immediately after the irradiation, the baking was continued for 90 seconds at 120 ° C on a hot plate (Post Exposure Bake; PEB).

Then, using a shower type developing device (ADE3000S manufactured by ACTES), the developer (23 ° C) described in Table 3 was rotated at a flow rate of 200 mL/min while rotating the wafer at 50 rpm. The spray was sprayed for 5 seconds to cover the developer on the wafer. Then, the rotation of the wafer was stopped and the wafer was allowed to stand for 60 seconds to perform development.

Thereafter, the wafer was rotated at 50 revolutions (rpm) while using the eluent described in Table 3 as a eluent (23 ° C) and sprayed at a flow rate of 200 mL/min for 30 seconds to perform rinsing. Processing, thereby obtaining a line-space (L/S) resist pattern of the wiring pattern at equal intervals.

(3) Evaluation of resist pattern Using a scanning electron microscope (S-9220, manufactured by Hitachi, Ltd.), the obtained resist pattern was evaluated for resolving power, LWR performance, and number of particles by the following method.

[Analytical property] The irradiation energy when the 1:1 line having a line width of 50 nm and the spatial pattern were analyzed was set as sensitivity (Eop). Among them, in Comparative Example 1-AR to Comparative Example 4-AR, it is impossible to analyze a 1:1 line and a space pattern having a line width of 50 nm, and therefore a 1:1 line and a space pattern having a line width of 100 nm are performed. The irradiation energy at the time of analysis is set to sensitivity (Eop). In this Eop, the minimum line width which is separated and analyzed by the ratio of the line to the space of 1:1 is set as the resolution (nm). The smaller the value, the better the performance.

[LWR performance] Regarding the LWR performance, a 1:1 line and space pattern having a line width of 50 nm under the Eop (wherein, regarding the comparative example 1-AR to the comparative example 4-AR, the line width is 100 nm) Measure the line width at any 50 points of 0.5 μm in the longitudinal direction of the 1:1 line and the space pattern, and find the standard deviation to calculate 3σ. The smaller the value, the better the performance.

[Number of Particles] After the prepared resist composition solution was allowed to stand at 4 ° C for one week, the number of particles having a particle diameter of 0.2 μm or more present in the solution was counted by a particle counter manufactured by Rion. The smaller the value, the better the performance.

[table 3]

[Example 1-B to Example 20-B, Comparative Example 1-BR to Comparative Example 4-BR (Extreme Ultraviolet (EUV) Exposure)] (4) Coating Liquid Preparation and Coating Utilization of Resist Composition 0.1 The film filter having a pore size of 1.5 μm was finely filtered with a coating composition having a solid concentration of 1.5% by mass of the composition shown in Table 4 below to obtain a resist composition solution. The resist composition solution was applied to a 6 吋 Si wafer previously treated with hexamethyldioxane (HMDS) using a spin coater Mark 8 manufactured by Tokyo Electron. The film was dried on a hot plate at 120 ° C for 60 seconds to obtain a resist film having a film thickness of 50 nm. In the case of Example 9-B, the composition for forming an upper layer film shown in Table 4 was further applied onto a resist film. Thereafter, baking was continued for 60 seconds at 120 ° C to form an upper film having a film thickness of 50 nm.

(5) EUV exposure and development The EBS exposure was performed on the wafer on which the resist film obtained in the above (4) was formed, NA (the number of lens openings, numerical aperture (Nortical Aperture)) was 0.3, and under the ring illumination. . The exposure apparatus used the NXE3100 manufactured by ASML.

After the irradiation, it was taken out from the EUV exposure apparatus, and immediately baked at 110 ° C for 60 seconds.

Then, using a shower type developing device (ADE3000S manufactured by ACTES), the developer described in Table 4 was irradiated at a flow rate of 200 mL/min while rotating the wafer at 50 rpm (23 ° C). The spray is ejected for a predetermined period of time to perform development.

Thereafter, the eluent (23 ° C) described in Table 4 below was sprayed at a flow rate of 200 mL/min for a predetermined time while the wafer was rotated at 50 rpm to perform a rinsing treatment. Finally, the wafer was dried by rotating at a high speed of 2,500 revolutions (rpm) for 120 seconds.

(6) Evaluation of Resist Pattern Using a scanning electron microscope (S-9220 manufactured by Hitachi, Ltd.), the obtained resist pattern was evaluated for analytical force, LWR, and number of particles by the following method.

[Analytical (isolated line)] The optimum exposure amount when the resist pattern having a line width of 50 nm (line: space = 1:4) was analyzed was set to sensitivity (Eopt) (mJ/cm ² ). The limit resolution (the minimum line width when the line and the space (line: space = 1:4) are separated and analyzed) in the obtained optimum exposure amount (Eopt) is set to the isolated line resolution (nm). In the comparative example 1-BR to the comparative example 4-BR, the resist pattern having a line width of 50 nm (line: space = 1:4) cannot be analyzed, so the line width is 100 nm (line: The irradiation energy when the resist pattern of the space=1:4) is analyzed is the sensitivity (Eop). The smaller the value, the more excellent the resolution and the better.

[LWR performance] Regarding the LWR performance, an isolated line pattern having a line width of 50 nm under the Eop (wherein, for the comparative example 1-BR to the comparative example 4-BR, an isolated line pattern having a line width of 100 nm) The line width is measured at any 50 points in the longitudinal direction of 0.5 μm, and the standard deviation is obtained to calculate 3σ. The smaller the value, the better the performance.

[Number of Particles] After the prepared resist composition solution was allowed to stand at 4 ° C for one week, the number of particles having a particle diameter of 0.2 μm or more present in the solution was counted by a particle counter manufactured by Rion. The smaller the value, the better the performance.

[Table 4]

[Example 1-C to Example 6-C, Comparative Example 1-CR to Comparative Example 3-CR (ArF immersion exposure)] (7) Preparation and coating of the resist composition on the ruthenium wafer The organic anti-reflection film ARC29SR (manufactured by Brewer Co., Ltd.) was coated thereon and baked at 205 ° C for 60 seconds to form an anti-reflection film having a film thickness of 86 nm, and the following Table 5 was applied thereon. The resist composition shown was baked at 100 ° C for 60 seconds to form a resist film having a film thickness of 90 nm. With respect to Example 1-C, Example 5-C, Example 6-C, Comparative Example 1-CR, and Comparative Example 2-CR, the composition for forming an upper layer film shown in Table 5 was further applied to a resist. On the membrane. Thereafter, baking was continued for 60 seconds at 100 ° C to form an upper film having a film thickness of 90 nm.

(8) ArF exposure and development using ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA1.20, C-Quad, outer sigma 0.730, inner sigma 0.630, XY bias) The half-tone mask (the hole portion is masked) of a square arrangement in which the mesoporous portion is 65 nm and the pitch between the holes is 100 nm is subjected to pattern exposure. As the immersion liquid, ultrapure water was used. Thereafter, it was heated at 105 ° C for 60 seconds (PEB: Post Exposure Bake). Then, development was carried out by coating with a developing solution described in the following Table 5 for 30 seconds, and rinsing was carried out by coating with a rinse liquid described in Table 5 below for 30 seconds. Then, the wafer was rotated at 2000 rpm for 30 seconds, thereby obtaining a hole pattern having a pore diameter of 50 nm.

(9) Evaluation of the resist pattern Using the scanning electron microscope (S-9220 manufactured by Hitachi, Ltd.), the obtained resist pattern was evaluated for the resolution and the number of particles by the following method.

[Resolvability (Hole Pattern)] The optimum exposure amount when the hole pattern having a pore diameter of 50 nm was analyzed was set to sensitivity (Eopt) (mJ/cm ² ). In the case of Comparative Example 1-CR to Comparative Example 3-CR, the hole pattern having a pore diameter of 50 nm cannot be analyzed. Therefore, the irradiation energy when analyzing the hole pattern having a line width of 100 nm is the sensitivity (Eop). . The minimum pore diameter when the limit resolution (hole pattern) in the obtained optimal exposure amount (Eopt) was separated and analyzed was defined as the resolution (nm). The smaller the value, the more excellent the resolution and the better.

[Number of Particles] After the prepared resist composition solution was allowed to stand at 4 ° C for one week, the number of particles having a particle diameter of 0.2 μm or more present in the solution was counted by a particle counter manufactured by Rion. The smaller the value, the better the performance.

[table 5]

As described in Tables 3 to 5, Examples 1-A to 20-A and Example 1-B using a resin (P) having a repeating unit (a) having an intramolecular salt structure In the examples 20-B and the examples 1-C to 6-C, the analytical properties, the LWR properties, and the number of particles were superior to those of the comparative examples. The reason is considered to be that the quencher is uniformly distributed in the system by the effect of introducing the intramolecular salt structure into the polymer, preventing the diffusion of the acid generated by the photoacid generator and controlling the aggregation caused by the intramolecular salt structure. . Further, as defined in Example 15-A and Example 5-B, the resin (P) containing the repeating unit (a) having an intramolecular salt structure is used as an alkali even if it is not used as a main polymer. The compound (quencher) is also effective. Further, as shown in Example 7-A, a resin (P) containing a repeating unit (a) having an intramolecular salt structure may be used as a hydrophobic resin by a combination with a fluorine component or the like. Thereby, the alkali component is biased to exist on the surface of the resist film, and the film thinning (top layer loss) can be improved in the positive pattern forming method, and the top stretching can be improved with respect to the negative pattern forming method (T-top (T -top) shape). Therefore, the pattern shape can also be improved by applying the resin (P) containing the repeating unit (a) having an intramolecular salt structure to the added polymer. [Industrial availability]

According to the present invention, there can be provided a resist composition, a resist film using the resist composition, a blank mask, a pattern forming method, and a method of manufacturing an electronic component, the resist composition being particularly When a pattern of ultrafine (for example, a line width of 50 nm) is formed, a pattern excellent in resolution and LWR performance can be formed, and the number of particles is small.

While the invention has been described with respect to the embodiments of the embodiments of the present invention The present application is based on Japanese Patent Application No. 2015-248041, filed on Dec.

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Claims (21)

A resist composition containing a resin (P) comprising a repeating unit (a) having an intramolecular salt structure. The resist composition according to claim 1, wherein the intramolecular salt structure is represented by the following general formula (U-1), general formula (U-2), or general formula (U-3) Any of the structures represented; In the general formula (U-1), the general formula (U-2), and the general formula (U-3), E ₁ and E ₂ represent a structure having a cation, and G ₁ and G ₂ represent a structure having an anion, and L ⁰ represents A single bond or a linking group; * indicates a linking site to the polymer main chain or side chain of the resin (P). The resist composition according to claim 1, wherein the repeating unit (a) is represented by the following general formula (i) or (ii); In the general formula (i) and the general formula (ii), Y ₁ , Y ₂ , R ₁₀₁ , R ₁₀₂ , R ₁₀₃ and R ₁₀₄ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, a nitro group or an organic group. L ₁ to L ₄ , Z ₁ and Z ₂ each independently represent a single bond or a divalent linking group; E ₁ and E ₂ represent a structure having a cation, and G ₁ and G ₂ represent a structure having an anion. The resist composition according to claim 1, wherein the repeating unit (a) is represented by the following general formula (i-1), general formula (i-2), and general formula (i-3) Or represented by the formula (ii-1); In the general formula (i-1), the general formula (i-2), the general formula (i-3), and the general formula (ii-1), Y ₁ , Y ₂ , R ₁₀₁ , R ₁₀₂ , R ₁₀₃ and R ₁₀₄ Each independently represents a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, a nitro group or an organic group; L ₁ to L ₄ , Z ₁ and Z ₂ each independently represent a single bond or a divalent linking group; and E ₁ represents a cation; , G ₁ represents a structure having an anion; R ₄₁ to R ₄₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and R ₄₁ and R ₄₂ may be bonded to each other to form a structure. Ring structure; R ₅₀ represents a substituent, k represents an integer of 0 to 4; and when k represents an integer of 2 or more, R ₅₀ may be the same or different. The resist composition according to claim 4, wherein the E ₁ is a group represented by the following (e1-1) or (e1-2), and the G ₁ is the following (g1- a base represented by any of 1) to (g1-5); In (e1-1) or (e1-2), R ₃₁ to R ₃₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and R ₃₁ and R ₃₂ may be bonded to each other. And forming a ring structure; * indicates a joint portion to L ₄ ; In (g1-1) to (g1-5), * indicates a connection site to L ₂ . The resist composition according to claim 1, wherein the resin (P) further comprises a repeating unit (b) represented by the following formula (A); In the above formula (A), R ₁₁ , R ₁₂ and R ₁₃ each independently represent a hydrogen atom, an alkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group; wherein R ₁₂ may bond with L to form a ring And R _{12 in} the above case represents a single bond or an alkylene group; X represents a single bond, -COO-, or -CONR ₃₀ -, R ₃₀ represents a hydrogen atom or an alkyl group; and L represents a single bond or an alkyl group; The m-valent aromatic ring group represents an (m+1)-valent aromatic ring group when bonded to R ₁₂ to form a ring; and Z may have a hydroxyl group as a substituent; m represents 1 to 5 Integer. The resist composition according to claim 1, wherein the resin (P) comprises a repeating unit (c) having a structure in which a polar group is decomposed and desorbed by an action of an acid. The resist composition according to claim 7, wherein the repeating unit (c) is a repeating unit represented by the following formula (AI) or formula (AII); In the general formula (AI) or the general formula (AII), Xa ₁ represents a hydrogen atom or an alkyl group; T represents a single bond or a divalent linking group; and Y represents a group which is desorbed by the action of an acid, and represents a group derived from -C(R). ₃₆ ) a group represented by (R ₃₇ )(OR ₃₈ ); R ₃₆ to R ₃₈ each independently represent a hydrogen atom or a monovalent organic group; R ₃₇ and R ₃₈ may be bonded to each other to form a ring; R ₆₁ , R ₆₂ and R ₆₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group; wherein R ₆₂ may be bonded to Ar ₆ to form a ring, in which case R ₆₂ represents a single bond or an alkyl group; X ₆ represents a single bond, -COO-, or -CONR ₆₄ -; R ₆₄ represents a hydrogen atom or an alkyl group; L ₆ represents a single bond or an alkyl group; and Ar ₆ represents (n+ 1) a valent aromatic ring group, in the case of bonding to R ₆₂ to form a ring, represents an (n+2)-valent aromatic ring group; in the case of n≧2, Y ₂ independently represents a hydrogen atom or a group which is desorbed by the action of an acid; wherein at least one of Y ₂ represents a group which is desorbed by the action of an acid, and represents a group represented by -C(R ₃₆ )(R ₃₇ )(OR ₃₈ ); R ₃₆ ～ R ₃₈ each independently represent a hydrogen atom or A monovalent organic group; R ₃₇ and R ₃₈ may be bonded to each other to form a ring; n-represents an integer of 1 to 4. The resist composition according to claim 8, wherein the repeating unit (c) is a repeating unit represented by the above formula (AII), and Y ₂ in the formula (AII) At least one of the groups desorbed by the action of an acid is a structure represented by the following formula (Y3-1); L ₁₀ represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group, L ₂₀ represents a tertiary alkyl group; M represents a single bond or a divalent linking group; and Q represents an alkyl group, a cycloalkyl group which may contain a hetero atom, An aryl group, an amine group, an ammonium group, a thiol group, a cyano group or an aldehyde group which may contain a hetero atom. The resist composition according to claim 8, wherein the repeating unit (c) is a repeating unit represented by the above formula (AII), and at least Y ₂ in the formula (AII) The group which is detached by the action of an acid is a structure represented by the following general formula (Y3-2); L ₁₀ represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group, L ₂₁ represents a secondary alkyl group; M represents a single bond or a divalent linking group; and Q represents an alkyl group, a cycloalkyl group which may contain a hetero atom, An aryl group, an amine group, an ammonium group, a thiol group, a cyano group or an aldehyde group which may contain a hetero atom. The resist composition according to claim 7, wherein the repeating unit (c) is a repeating unit represented by the following formula (AI-2); In the formula (AI-2), Xa ₁ represents a hydrogen atom or an alkyl group; T represents a single bond or a divalent linking group; and Y is a group which is desorbed by the action of an acid, and represents a formula (Y1) of the following formula: a group represented by the formula (Y2) or the formula (Y4); a formula (Y1): -C(Rx ₁ )(Rx ₂ )(Rx ₃ ), a formula (Y2): -C(=O)O (Rx ₁ )(Rx ₂ )(Rx ₃ ) Formula (Y4): -C(Rn)(H)(Ar) In the formula (Y1) and the formula (Y2), Rx ₁ to Rx ₃ are independently In the formula (Y4), Ar represents an aromatic ring group; Rn represents an alkyl group, a cycloalkyl group or an aryl group; and Rn and Ar may be bonded to each other to form a non-aromatic ring. The resist composition according to claim 7, wherein the repeating unit (c) is a repeating unit represented by the following formula (AII-2); In the formula (AII-2), R ₆₁ , R ₆₂ and R ₆₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group; wherein R ₆₂ may be bonded to Ar ₆ bonded to form a ring, R ₆₂ in the case where a single bond or alkylene; _X-6 represents a single bond, -COO-, or -CONR ₆₄ -; R ₆₄ represents a hydrogen atom or an alkyl group; L represents ₆ a single bond or an alkyl group; Ar ₆ represents an (n+1)-valent aromatic ring group, and when it is bonded to R ₆₂ to form a ring, it represents an (n+2)-valent aromatic ring group; n represents 1 to An integer of 4; in the case of n≧2, Y ₂ each independently represents a hydrogen atom or a group which is desorbed by the action of an acid; wherein at least one of Y ₂ represents a group which is desorbed by the action of an acid, and is represented by a group represented by the formula (Y1), (Y2) or (Y4); a formula (Y1): -C(Rx ₁ )(Rx ₂ )(Rx ₃ ), a formula (Y2): -C(= O)O(Rx ₁ )(Rx ₂ )(Rx ₃ ) General formula (Y4): -C(Rn)(H)(Ar) In the formula (Y1), in the formula (Y2), Rx ₁ to Rx ₃ Each independently represents an alkyl group or a cycloalkyl group; in the formula (Y4), Ar represents an aromatic ring group; and Rn represents an alkyl group, a cycloalkyl group or Group; and Rn of Ar may be bonded to each other to form a non-aromatic ring. The resist composition according to any one of claims 1 to 12, wherein the resin (P) further contains a group selected from a fluorine atom, a group having a fluorine atom, and a germanium atom. One or more groups selected from the group consisting of an alkyl group having 6 or more carbon atoms, a cycloalkyl group having 5 or more carbon atoms, an aryl group having 6 or more carbon atoms, and an aralkyl group having 7 or more carbon atoms Repeat unit. The resist composition according to any one of claims 1 to 12, further comprising a compound which generates an acid by irradiation with actinic rays or radiation. A resist film formed of the resist composition according to any one of claims 1 to 12. A blank mask having a resist film as described in claim 15 of the patent application. A pattern forming method comprising: (a) a step of forming a resist film by the resist composition according to any one of claims 1 to 12, (c) by actinicizing a step of exposing the resist film by radiation or radiation, and (d) a step of developing the exposed resist film with a developing solution. The pattern forming method according to claim 17, wherein the actinic ray or radiation is an electron beam or an extreme ultraviolet ray. The pattern forming method according to claim 17, wherein the developing solution is developed by using a developing solution containing an organic solvent to form a negative pattern. The pattern forming method according to claim 17, wherein the developing solution is developed by using an alkaline developing solution to form a positive pattern. A method of manufacturing an electronic component, comprising the pattern forming method according to claim 17 of the patent application.