JP5740504B2 - Actinic ray-sensitive or radiation-sensitive resin composition and pattern forming method using the same - Google Patents

Description

  The present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition and a pattern forming method using the same. More specifically, the present invention relates to a composition suitable for a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal and a thermal head, and other photofabrication lithography processes, and a pattern forming method using the composition. . In particular, the present invention relates to an ArF exposure apparatus, an ArF immersion projection exposure apparatus and an EUV exposure apparatus that use far ultraviolet light having a wavelength of 300 nm or less as a light source, and a pattern formation using the composition. Regarding the method.

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

  In addition, “exposure” means not only light irradiation with a mercury lamp, far ultraviolet rays, X-rays, EUV light, etc., but also drawing with particle beams such as electron beams and ion beams, unless otherwise specified. .

  Since the resist for KrF excimer laser (248 nm), a pattern formation method using chemical amplification has been used to compensate for the sensitivity reduction due to light absorption. For example, in the positive chemical amplification method, first, a photoacid generator contained in an exposed portion is decomposed by light irradiation to generate an acid. Then, in the post exposure bake (PEB) process or the like, the alkali-insoluble group contained in the photosensitive composition is changed to an alkali-soluble group by the catalytic action of the generated acid. Thereafter, development is performed using, for example, an alkaline solution. Thereby, an exposed part is removed and a desired pattern is obtained.

  In the above method, various alkali developers have been proposed. For example, as this alkaline developer, a 2.38 mass% TMAH (tetramethylammonium hydroxide aqueous solution) aqueous alkaline developer is generally used.

  To reduce the size of semiconductor elements, the exposure light source has become shorter and the projection lens has a higher numerical aperture (high NA). Currently, an exposure machine using an ArF excimer laser having a wavelength of 193 nm as a light source has been developed. ing. As a technique for further increasing the resolving power, a method of filling a liquid having a high refractive index (hereinafter also referred to as “immersion liquid”) between the projection lens and the sample (that is, an immersion method) has been proposed. In addition, EUV lithography in which exposure is performed with ultraviolet light having a shorter wavelength (13.5 nm) has also been proposed.

  However, in reality, it is extremely difficult to find an appropriate combination of a resist composition, a developing solution, a rinsing solution and the like necessary for forming a pattern having comprehensively excellent performance. In particular, as the resolution line width of the resist becomes finer, improvements in roughness performance of line patterns and in-plane uniformity of pattern dimensions are required.

  In recent years, various configurations have been proposed as positive resist compositions (see, for example, Patent Documents 1 to 4). Development of negative resist compositions in pattern formation by alkali development has also been carried out (see, for example, Patent Documents 5 to 8). This is because, in the manufacture of semiconductor elements and the like, there is a demand for pattern formation having various shapes such as lines, trenches, and holes, but there are patterns that are difficult to form with current positive resists. .

  In recent years, a pattern forming method using a negative developer, that is, a developer containing an organic solvent is being developed (see, for example, Patent Documents 9 to 11). For example, Patent Document 11 discloses a step of applying a positive resist composition on a substrate, which increases the solubility in a positive developer and decreases the solubility in a negative developer by irradiation with actinic rays or radiation. There is disclosed a pattern forming method including an exposure step and a step of developing using a negative developer. According to this method, a highly accurate fine pattern can be stably formed.

  However, the above-described composition is required to further improve development defect performance, immersion defect performance, pattern shape, and limit resolution.

JP 2008-203639 A JP 2007-146613 A JP 2006-131739 A JP 2000-122295 A JP 2006-317803 A JP 2006-259582 A JP 2006-195050 A JP 2000-206694 A JP 2008-281974 A JP 2008-281975 A JP 2008-292975 A

  An object of the present invention is to provide an actinic ray-sensitive or radiation-sensitive resin composition that is excellent in development defect performance, immersion defect performance, and critical resolution, and that can form a pattern having a good shape, and It is to provide a pattern forming method used.

For example, the present invention is as follows.
[1] A resin containing a first repeating unit having a group capable of decomposing by the action of an acid to generate an alcoholic hydroxy group and having reduced solubility in a developer containing an organic solvent by the action of an acid, actinic rays or radiation An actinic ray-sensitive or radiation-sensitive resin composition containing a compound that generates an acid upon irradiation with a hydrophobic resin.

  [2] The composition according to [1], wherein the hydrophobic resin contains at least one of a fluorine atom and a silicon atom.

  [3] The composition according to [1] or [2], which is used for development with a developer containing an organic solvent.

  [4] The composition according to any one of [1] to [3], wherein the hydrophobic resin includes a second repeating unit having a carboxy group.

  [5] The hydrophobic resin does not contain a third repeating unit having a group that decomposes by the action of an acid, or contains the third repeating unit and the content thereof is 20 mol based on all repeating units. % Of the composition according to any one of [1] to [4].

  [6] The composition according to any one of [1] to [5], further including a solvent, wherein the solvent includes a liquid having a normal boiling point of 180 ° C. or higher.

[7] The first repeating unit is any one of [1] to [6] represented by at least one selected from the group consisting of the following general formulas (I-1) to (I-10): Composition.

Where
Each Ra independently represents a hydrogen atom, an alkyl group, or a group represented by —CH ₂ —O—Ra ₂ . Here, Ra2 represents a hydrogen atom, an alkyl group, or an acyl group.
R ₁ represents an (n + 1) valent organic group.
R ₂ independently represents a single bond or an (n + 1) -valent organic group when m ≧ 2.
OP each independently represents the above group which decomposes by the action of an acid to produce an alcoholic hydroxy group. When n ≧ 2 and / or m ≧ 2, two or more OPs may be bonded to each other to form a ring.
W represents a methylene group, an oxygen atom or a sulfur atom.
n and m represent an integer of 1 or more.
l represents an integer of 0 or more.
L ₁ represents a linking group represented by —COO—, —OCO—, —CONH—, —O—, —Ar—, —SO ₃ — or —SO ₂ NH—. Here, Ar represents a divalent aromatic ring group.

Each R independently represents a hydrogen atom or an alkyl group.
R ₀ represents a hydrogen atom or an organic group.
L ₃ represents a (m + 2) -valent linking group.
R ^L each independently represents an (n + 1) -valent linking group when m ≧ 2.
R ^S each independently represents a substituent when p ≧ 2. For p ≧ 2, plural structured R ^S may be bonded to each other to form a ring.
p represents an integer of 0 to 3.

[8] The group which is decomposed by the action of an acid to produce an alcoholic hydroxy group is represented by at least one selected from the group consisting of the following general formulas (II-1) to (II-9) [1 ] The composition in any one of-[7].

Where
R ₃ each independently represents a hydrogen atom or a monovalent organic group. Two R _{3 s} may be bonded to each other to form a ring.
R ₄ each independently represents a monovalent organic group. At least two R ₄ may be bonded to each other to form a ring. R ₃ and R ₄ may be bonded to each other to form a ring.
R ₅ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, or an alkynyl group. At least two R ₅ may be bonded to each other to form a ring. However, when one or two of the three R ₅ are hydrogen atoms, at least one of the remaining R ₅ represents an aryl group, an alkenyl group, or an alkynyl group.
R ₆ each independently represents a hydrogen atom or a monovalent organic group. R ₆ may be bonded to each other to form a ring.

[9] The composition according to any one of [1] to [8], wherein the repeating unit is represented by the following general formula (III).

Where
R ₁ represents an (n + 1) valent organic group.
Ra represents a hydrogen atom, an alkyl group, or a group represented by —CH ₂ —O—Ra ₂ . Here, Ra2 represents a hydrogen atom, an alkyl group, or an acyl group.
R ₃ each independently represents a hydrogen atom or a monovalent organic group. R ₃ may be bonded to each other to form a ring.
R ₄ each independently represents a monovalent organic group when n ≧ 2. R ₄ may be bonded to each other to form a ring. R ₃ and R ₄ may be bonded to each other to form a ring.

n represents an integer of 1 or more.

  [10] A resist pattern formed using the composition according to any one of [1] to [9].

  [11] Forming a film using the composition according to any one of [1] to [9], (B) exposing the film, and (C) developing the exposed film And a pattern forming method.

  [12] The method according to [11], wherein the exposure is performed through an immersion liquid.

  [13] The method according to [11] or [12], wherein the development is performed using a developer containing an organic solvent.

  According to the present invention, an actinic ray-sensitive or radiation-sensitive resin composition that is excellent in development defect performance, immersion defect performance, and critical resolution, and that can form a pattern having a good shape, and uses the same It is possible to provide a conventional pattern forming method.

The SEM photograph which shows an example of a liquid immersion defect.

Hereinafter, embodiments of the present invention will be described in detail.
Here, the groups and atomic groups that do not explicitly indicate substitution or non-substitution include both those that do not have a substituent and those that have a substituent. For example, an “alkyl group” that does not clearly indicate substitution or unsubstituted is not only an alkyl group that does not have a substituent (unsubstituted alkyl group) but also an alkyl group that has a substituent (substituted alkyl group) Is also included.

<Actinic ray-sensitive or radiation-sensitive resin composition>
First, the actinic ray-sensitive or radiation-sensitive resin composition according to the present invention will be described. This composition may be used for negative development or positive development. That is, this composition may be used for development using a developer containing an organic solvent, or may be used for development using an alkali developer. The composition according to the present invention is typically used for negative development, that is, development using a developer containing an organic solvent. That is, the composition according to the present invention is typically a negative resist composition.

  The composition according to the present invention comprises (a) a resin whose solubility in a developer containing an organic solvent is reduced by the action of an acid (hereinafter also referred to as an acid-decomposable resin), and (b) irradiation with actinic rays or radiation. It contains an acid-generating compound (hereinafter also referred to as an acid generator) and (c) a hydrophobic resin. Further, the composition may further contain at least one of (d) a basic compound, (e) a solvent, (f) a surfactant, and (g) other additives. Hereinafter, each of these components will be described in order.

(A) Acid-decomposable resin The composition according to the present invention contains an acid-decomposable resin. The acid-decomposable resin includes a repeating unit (P) having a group that decomposes by the action of an acid to generate an alcoholic hydroxy group as an acid-decomposable group.

  In the case where at least part of the acid-decomposable group is a group that decomposes by the action of an acid to generate an alcoholic hydroxy group, for example, the acid-decomposable group decomposes by the action of an acid to form a carboxy group. It has been found that, for example, sensitivity, limit resolving power, roughness characteristics, exposure latitude (EL), post-exposure heating (PEB) temperature dependency, and focus margin (DOF) are improved as compared with the case where only the generated group is formed. ing. The reason for this is not always clear, but the present inventors speculate as follows. That is, the present inventors have improved the reactivity of the acid-decomposable resin as well as the acid-decomposability by using a group that decomposes by the action of an acid to generate an alcoholic hydroxy group as at least a part of the acid-decomposable group. This is considered to be because the polarity change of the resin due to the decomposition of the group becomes large and the dissolution contrast with respect to the developer containing the organic solvent is improved.

  In addition, when the present invention is a group in which at least a part of the acid-decomposable group is decomposed by the action of an acid to generate an alcoholic hydroxy group, the acid-decomposable group is decomposed by the action of an acid to form a carboxy group. It has been found that, for example, a decrease in film thickness during post-exposure heating (PEB) can be suppressed as compared with the case where only the generated groups are formed. The present inventors believe that this is because the change in the polarity of the resin before and after decomposition by the action of an acid is greater in the former case than in the latter case. This difference in the magnitude of the polarity change is particularly remarkable when the molecular weight of the protecting group that is eliminated by the action of an acid is small.

  The pKa of the alcoholic hydroxy group that can be generated by the above group being decomposed by the action of an acid is, for example, 12 or more, and typically 12 or more and 20 or less. If this pKa is excessively small, the stability of the composition containing the acid-decomposable resin is lowered, and the performance variation with time may increase. Here, “pKa” is a value calculated using “ACD / pKa DB” manufactured by Fujitsu Limited under an initial setting that is not customized.

  The repeating unit (P) preferably has two or more groups that decompose by the action of an acid to generate an alcoholic hydroxy group. If it carries out like this, the limit resolving power and roughness characteristic of the composition containing acid-decomposable resin can further be improved.

The repeating unit (P) is preferably represented by at least one selected from the group consisting of the following general formulas (I-1) to (I-10). The repeating unit is more preferably represented by at least one selected from the group consisting of the following general formulas (I-1) to (I-3), and is represented by the following general formula (I-1). More preferably.

Where
Each Ra independently represents a hydrogen atom, an alkyl group, or a group represented by —CH ₂ —O—Ra ₂ . Here, Ra2 represents a hydrogen atom, an alkyl group, or an acyl group.
R ₁ represents an (n + 1) valent organic group.
R ₂ independently represents a single bond or an (n + 1) -valent organic group when m ≧ 2.
OP each independently represents the above group which decomposes by the action of an acid to produce an alcoholic hydroxy group. When n ≧ 2 and / or m ≧ 2, two or more OPs may be bonded to each other to form a ring.
W represents a methylene group, an oxygen atom or a sulfur atom.
n and m represent an integer of 1 or more. In general formula (I-2), (I-3) or (I-8), n is 1 when R ₂ represents a single bond.
l represents an integer of 0 or more.
L ₁ represents a linking group represented by —COO—, —OCO—, —CONH—, —O—, —Ar—, —SO ₃ — or —SO ₂ NH—. Here, Ar represents a divalent aromatic ring group.

Each R independently represents a hydrogen atom or an alkyl group.
R ₀ represents a hydrogen atom or an organic group.
L ₃ represents a (m + 2) -valent linking group.
R ^L each independently represents an (n + 1) -valent linking group when m ≧ 2.
R ^S each independently represents a substituent when p ≧ 2. For p ≧ 2, plural structured R ^S may be bonded to each other to form a ring.
p represents an integer of 0 to 3.

Ra represents a hydrogen atom, an alkyl group, or a group represented by —CH ₂ —O—Ra ₂ . Ra is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and more preferably a hydrogen atom or a methyl group.

  W represents a methylene group, an oxygen atom or a sulfur atom. W is preferably a methylene group or an oxygen atom.

R ₁ represents an (n + 1) valent organic group. R ₁ is preferably a non-aromatic hydrocarbon group. In this case, R ₁ may be a chain hydrocarbon group or an alicyclic hydrocarbon group. R ₁ is more preferably an alicyclic hydrocarbon group.

R ₂ represents a single bond or an (n + 1) valent organic group. R ₂ is preferably a single bond or a non-aromatic hydrocarbon group. In this case, R ₂ may be a chain hydrocarbon group or an alicyclic hydrocarbon group.

When R ₁ and / or R ₂ is a chain hydrocarbon group, the chain hydrocarbon group may be linear or branched. The chain hydrocarbon group preferably has 1 to 8 carbon atoms. For example, when R ₁ and / or R ₂ is an alkylene group, R ₁ and / or R ₂ are methylene group, ethylene group, n-propylene group, isopropylene group, n-butylene group, isobutylene group or sec- A butylene group is preferred.

When R ₁ and / or R ₂ is an alicyclic hydrocarbon group, the alicyclic hydrocarbon group may be monocyclic or polycyclic. This alicyclic hydrocarbon group has, for example, a monocyclo, bicyclo, tricyclo or tetracyclo structure. The carbon number of this alicyclic hydrocarbon group is usually 5 or more, preferably 6 to 30, and more preferably 7 to 25.

Examples of the alicyclic hydrocarbon group include those having the partial structures listed below. Each of these partial structures may have a substituent. In each of these partial structures, the methylene group (—CH ₂ —) includes an oxygen atom (—O—), a sulfur atom (—S—), a carbonyl group [—C (═O) —], a sulfonyl group [ -S (= O) _2- ], a sulfinyl group [-S (= O)-], or an imino group [-N (R)-] (R is a hydrogen atom or an alkyl group).

For example, when R ₁ and / or R ₂ is a cycloalkylene group, R ₁ and / or R ₂ may be an adamantylene group, a noradamantylene group, a decahydronaphthylene group, a tricyclodecanylene group, a tetracyclododeca group. Nylene group, norbornylene group, cyclopentylene group, cyclohexylene group, cycloheptylene group, cyclooctylene group, cyclodecanylene group, or cyclododecanylene group are preferable, and adamantylene group, norbornylene group, cyclohexylene group, cyclopentylene It is more preferable that they are a len group, a tetracyclododecanylene group, or a tricyclodecanylene group.

The non-aromatic hydrocarbon group of R ₁ and / or R ₂ may have a substituent. Examples of the substituent include an alkyl group having 1 to 4 carbon atoms, a halogen atom, a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, a carboxy group, and an alkoxycarbonyl group having 2 to 6 carbon atoms. The above alkyl group, alkoxy group and alkoxycarbonyl group may further have a substituent. As this substituent, a hydroxy group, a halogen atom, and an alkoxy group are mentioned, for example.

L ₁ represents a linking group represented by —COO—, —OCO—, —CONH—, —O—, —Ar—, —SO ₃ — or —SO ₂ NH—. Here, Ar represents a divalent aromatic ring group. L ₁ is preferably a linking group represented by —COO—, —CONH— or —Ar—, and more preferably a linking group represented by —COO— or —CONH—.

  R represents a hydrogen atom or an alkyl group. The alkyl group may be linear or branched. Carbon number of this alkyl group becomes like this. Preferably it is 1-6, More preferably, it is 1-3. R is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

R ₀ represents a hydrogen atom or an organic group. Examples of the organic group include an alkyl group, a cycloalkyl group, an aryl group, an alkynyl group, and an alkenyl group. R ₀ is preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom or a methyl group.

L ₃ represents a (m + 2) -valent linking group. That is, L ₃ represents a trivalent or higher linking group. Examples of such a linking group include corresponding groups in specific examples described later.

R ^L represents a (n + 1) -valent linking group. That is, R ^L represents a divalent or higher linking group. Examples of such a linking group include an alkylene group, a cycloalkylene group, and corresponding groups in the specific examples described below. R ^L may be bonded to each other or bonded to the following R ^S to form a ring structure.

R ^S represents a substituent. Examples of the substituent include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an acyloxy group, an alkoxycarbonyl group, and a halogen atom.

  n is an integer of 1 or more. n is preferably an integer of 1 to 3, and more preferably 1 or 2. When n is 2 or more, it is possible to further improve the dissolution contrast with respect to a developer containing an organic solvent. Accordingly, in this way, the limit resolution and roughness characteristics can be further improved.

m is an integer of 1 or more. m is preferably an integer of 1 to 3, and more preferably 1 or 2.
l is an integer of 0 or more. l is preferably 0 or 1.
p is an integer of 0-3.

Specific examples of the repeating unit having a group that decomposes by the action of an acid to generate an alcoholic hydroxy group are shown below. In specific examples, Ra and OP have the same meanings as in general formulas (I-1) to (I-3). Further, when a plurality of OPs are bonded to each other to form a ring, the corresponding ring structure is represented as “OPO” for convenience.

The group that decomposes by the action of an acid to produce an alcoholic hydroxy group is preferably represented by at least one selected from the group consisting of the following general formulas (II-1) to (II-4).

Where
R ₃ each independently represents a hydrogen atom or a monovalent organic group. R ₃ may be bonded to each other to form a ring.
R ₄ each independently represents a monovalent organic group. R ₄ may be bonded to each other to form a ring. R ₃ and R ₄ may be bonded to each other to form a ring.
R ₅ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, or an alkynyl group. At least two R ₅ may be bonded to each other to form a ring. However, when one or two of the three R ₅ are hydrogen atoms, at least one of the remaining R ₅ represents an aryl group, an alkenyl group, or an alkynyl group.

The group that decomposes by the action of an acid to produce an alcoholic hydroxy group is also preferably represented by at least one selected from the group consisting of the following general formulas (II-5) to (II-9).

Where
R ₄ has the same meaning as in general formulas (II-1) to (II-3).
R ₆ each independently represents a hydrogen atom or a monovalent organic group. R ₆ may be bonded to each other to form a ring.
The group that decomposes by the action of an acid to produce an alcoholic hydroxy group is more preferably represented by at least one selected from the general formulas (II-1) to (II-3). More preferably, it is represented by 1) or (II-3), and particularly preferably represented by formula (II-1).

R ₃ represents a hydrogen atom or a monovalent organic group as described above. R ₃ is preferably a hydrogen atom, an alkyl group or a cycloalkyl group, more preferably a hydrogen atom or an alkyl group.

The alkyl group for R ₃ may be linear or branched. The number of carbon atoms in the alkyl group of R ₃ is preferably 1 to 10, and more preferably 1 to 3. Examples of the alkyl group for R ₃ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group.

The cycloalkyl group for R ₃ may be monocyclic or polycyclic. The number of carbon atoms in the cycloalkyl group represented by R ₃ is preferably 3 to 10, and more preferably 4 to 8. Examples of the cycloalkyl group represented by R ₃ include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group.

In the general formula (II-1), at least one of R ₃ is preferably a monovalent organic group. When such a configuration is employed, particularly high sensitivity can be achieved.

R ₄ represents a monovalent organic group. R ₄ is preferably an alkyl group or a cycloalkyl group, and more preferably an alkyl group. These alkyl groups and cycloalkyl groups may have a substituent.

The alkyl group represented by R ₄ preferably has no substituent, or preferably has one or more aryl groups and / or one or more silyl groups as substituents. The carbon number of the unsubstituted alkyl group is preferably 1-20. It is preferable that carbon number of the alkyl group part in the alkyl group substituted by one or more aryl groups is 1-25. It is preferable that carbon number of the alkyl group part in the alkyl group substituted by the 1 or more silyl group is 1-30. Also, if the cycloalkyl group R ₄ does not have a substituent, the carbon number thereof is preferably from 3 to 20.

R ₅ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, or an alkynyl group. However, when one or two of the three R ₅ are hydrogen atoms, at least one of the remaining R ₅ represents an aryl group, an alkenyl group, or an alkynyl group. R ₅ is preferably a hydrogen atom or an alkyl group. The alkyl group may have a substituent or may not have a substituent. When the alkyl group does not have a substituent, the carbon number is preferably 1 to 6, and preferably 1 to 3.

R ₆ represents a hydrogen atom or a monovalent organic group as described above. R ₆ is preferably a hydrogen atom, an alkyl group or a cycloalkyl group, more preferably a hydrogen atom or an alkyl group, and further preferably a hydrogen atom or an alkyl group having no substituent. R ₆ is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms and having no substituent.

Examples of the alkyl group and cycloalkyl group of R ₄ , R _5, and R ₆ include the same as those described above for R ₃ .

Below, the specific example of the group which decomposes | disassembles by the effect | action of an acid and produces an alcoholic hydroxy group is shown.

  The acid-decomposable resin may contain two or more types of repeating units (P) having a group that decomposes by the action of an acid to generate an alcoholic hydroxy group. Employing such a configuration makes it possible to finely adjust the reactivity and / or developability and facilitate optimization of various performances.

  The content of the repeating unit having a group that decomposes by the action of an acid to generate an alcoholic hydroxy group is preferably in the range of 10 mol% to 100 mol%, more preferably, based on all repeating units of the acid-decomposable resin. Is in the range of 30 mol% to 90 mol%, more preferably in the range of 50 mol% to 80 mol%.

  The acid-decomposable resin may further contain other repeating units in addition to the repeating unit (P). Examples of other repeating units include those described below.

(A) Repeating unit having a polar group The acid-decomposable resin preferably further contains a repeating unit (A) having a polar group. If it carries out like this, the sensitivity of the composition containing acid-decomposable resin can further be improved, for example.

  Examples of the “polar group” that the repeating unit (A) may contain include the following (1) to (4). In the following, “electronegativity” means a value by Pauling.

(1) A functional group including a structure in which an oxygen atom and an atom having an electronegativity difference of 1.1 or more are bonded by a single bond. Examples of such a polar group include a hydroxy group and the like. And a group containing a structure represented by O—H.

(2) Functional group including a structure in which a nitrogen atom and an atom having a difference in electronegativity of the nitrogen atom of 0.6 or more are bonded by a single bond. Examples of such a polar group include an amino group and the like. And a group containing a structure represented by N—H.

(3) Functional group including a structure in which two atoms having electronegativity different by 0.5 or more are bonded by a double bond or a triple bond. Examples of such a polar group include C≡N, C═O, N = And a group containing a structure represented by O, S═O or C═N.

(4) Functional group having an ionic moiety Examples of such a polar group include a group having a moiety represented by N ⁺ or S ⁺ .

  The “polar group” that the repeating unit (A) can contain includes, for example, (I) hydroxy group, (II) cyano group, (III) lactone group, (IV) carboxy group or sulfonic acid group, (V) amide group, It is at least one selected from the group consisting of a group corresponding to a sulfonamide group or a derivative thereof, (VI) an ammonium group or a sulfonium group, and a group formed by combining two or more thereof.

This polar group is particularly preferably an alcoholic hydroxy group, a cyano group, a lactone group, or a group containing a cyanolactone structure.
When the acid-decomposable resin further contains a repeating unit having an alcoholic hydroxy group, the exposure latitude (EL) of the composition containing the acid-decomposable resin can be further improved.
When the acid-decomposable resin further contains a repeating unit having a cyano group, the sensitivity of the composition containing the acid-decomposable resin can be further improved.
If the acid-decomposable resin further contains a repeating unit having a lactone group, the dissolution contrast with respect to the developer containing an organic solvent can be further improved. This also makes it possible to further improve the dry etching resistance, coating properties, and adhesion to the substrate of the composition containing the acid-decomposable resin.

  When the acid-decomposable resin further contains a repeating unit having a group containing a lactone structure having a cyano group, the dissolution contrast with respect to a developer containing an organic solvent can be further improved. This also makes it possible to further improve the sensitivity, dry etching resistance, applicability, and adhesion to the substrate of the composition containing the acid-decomposable resin. In addition, this makes it possible for a single repeating unit to have a function attributable to each of the cyano group and the lactone group, thereby further increasing the degree of freedom in designing the acid-decomposable resin.

Specific examples of structures that the “polar group” may contain are given below.

  As a preferable repeating unit (A), for example, in the above repeating unit (P), “alcoholic hydroxy group” in which “a group that decomposes by the action of an acid to generate an alcoholic hydroxy group” is substituted. Is mentioned.

Such a repeating unit (A) preferably has a structure in which “OP” is replaced with “OH” in each of the general formulas (I-1) to (I-10). That is, this repeating unit is preferably represented by at least one selected from the group consisting of the following general formulas (I-1H) to (I-10H). In particular, the repeating unit (A) is more preferably represented by at least one selected from the group consisting of the following general formulas (I-1H) to (I-3H). More preferably, it is represented by 1H).

In the formula, Ra, R ₁ , R ₂ , OP, W, n, m, l, L ₁ , R, R ₀ , L ₃ , R ^L , R ^S and p are represented by the general formulas (I-1) to ( It is synonymous with each in I-10).

  A repeating unit having a group capable of decomposing by the action of an acid to generate an alcoholic hydroxy group, and a repeating unit represented by at least one selected from the group consisting of the above general formulas (I-1H) to (I-10H) When the unit is used in combination, for example, by suppressing acid diffusion due to an alcoholic hydroxy group and increasing sensitivity due to a group that decomposes by the action of an acid to generate an alcoholic hydroxy group, without degrading other performances, The exposure latitude (EL) can be improved.

  In the above repeating unit (P), the content of the repeating unit (A) obtained by substituting the “group that generates an alcoholic hydroxy group by decomposition by the action of an acid” with an “alcoholic hydroxy group” is determined by acid decomposition. 5-100 mol% is preferable with respect to all the repeating units in a conductive resin, More preferably, it is 10-90 mol%, More preferably, it is 20-80 mol%.

Specific examples of the repeating unit represented by any one of the general formulas (I-1H) to (I-10H) are shown below. In specific examples, Ra is as defined in general formulas (I-1H) to (I-10H).

  Other preferable repeating units (A) include, for example, repeating units having a hydroxy group or a cyano group. This improves the substrate adhesion and developer compatibility.

The repeating unit having a hydroxy group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxy group or a cyano group, and preferably has no acid-decomposable group. The alicyclic hydrocarbon structure in the alicyclic hydrocarbon structure substituted with a hydroxy group or a cyano group is preferably an adamantyl group, a diamantyl group, or a norbornane group. As the alicyclic hydrocarbon structure substituted with a preferred hydroxy group or cyano group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferable.

In general formulas (VIIa) to (VIIc),
R ₂ c to R ₄ c each independently represents a hydrogen atom, a hydroxy group, or a cyano group. However, at least one of R ₂ c to R ₄ c represents a hydroxy group or a cyano group. Preferably, one or _two members out of R ₂ c to R ₄ c are a hydroxy group and the remaining is a hydrogen atom. In general formula (VIIa), it is more preferable that _two members out of R ₂ c to R ₄ c are hydroxy groups and the rest are hydrogen atoms.

Examples of the repeating unit having a partial structure represented by general formulas (VIIa) to (VIId) include repeating units represented by the following general formulas (AIIa) to (AIId).

In the general formulas (AIIa) to (AIId),
R ₁ c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

R ₂ c to R ₄ c are in the general formula (VIIa) ~ (VIIc), same meanings as R ₂ c~R ₄ c.

  The content of the repeating unit having a hydroxy group or a cyano group is preferably from 5 to 70 mol%, more preferably from 5 to 60 mol%, still more preferably from 10 to 50 mol%, based on all repeating units in the acid-decomposable resin. .

Specific examples of the repeating unit having a hydroxy group or a cyano group are given below, but the present invention is not limited thereto.

  Other preferable repeating units (A) include, for example, repeating units having a lactone structure.

  The repeating unit having a lactone structure preferably has a 5- to 7-membered lactone structure, and other ring structures are condensed to form a bicyclo structure or a spiro structure on the 5- to 7-membered lactone structure. A ring is more preferable.

More specifically, a lactone structure represented by any one of the following general formulas (LC1-1) to (LC1-17) can be given. Preferred lactone structures include (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14) and (LC1-17). . By using specific lactone structures, line edge roughness and development defects can be further reduced.

Wherein, Rb ₂ represents a substituent, _{n 2} represents an integer of 0-4. n ₂ is preferably an integer of 0 to 2.
Preferred examples of Rb ₂ include alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 4 to 7 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, alkoxycarbonyl groups having 1 to 8 carbon atoms, carboxy groups, and halogens. Examples include an atom, a hydroxy group, a cyano group, and an acid-decomposable group described later. Among these, an alkyl group having 1 to 4 carbon atoms, a cyano group, or an acid-decomposable group is particularly preferable. When n ₂ ≧ 2, the plurality of Rb ₂ may be the same as each other or different from each other. In addition, the plurality of Rb ₂ may be bonded to each other to form a ring.

Examples of the repeating unit having a lactone structure include a repeating unit represented by the following general formula (AII ′).

In general formula (AII ′),
Rb ₀ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group of Rb ₀ may have include a hydroxy group and a halogen atom. Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Preferred are a hydrogen atom, a methyl group, a hydroxymethyl group, and a trifluoromethyl group, and a hydrogen atom and a methyl group are particularly preferred.
V represents a group having a structure represented by any one of the general formulas (LC1-1) to (LC1-17).

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

Preferable examples of the repeating unit having a lactone structure include the following repeating units. By selecting an optimal lactone group, for example, the pattern profile and / or density dependence can be optimized.

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

The repeating unit having a lactone group may be a repeating unit represented by the following general formula (1).

In general formula (1),
A represents an ester bond or an amide bond.
R ₀ independently represents an alkylene group, a cycloalkylene group, or a combination thereof when n _S ≧ 2.
Z is independently an ether bond, an ester bond, an amide bond, or a urethane bond when n _S ≧ 2.

Or urea bond

Represents. In the formula, R represents, for example, a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group.
R ₈ represents a monovalent organic group having a lactone structure.
n _S represents an integer of 1 to 5. n _S is preferably 1.
R ₇ represents a hydrogen atom, an alkyl group or a halogen atom. This alkyl group may have a substituent. R ₇ preferably represents a hydrogen atom, a methyl group, a hydroxymethyl group or an acetoxymethyl group.

As described above, R ₀ represents an alkylene group, a cycloalkylene group, or a combination thereof.
The alkylene group as R ₀ may be linear or branched. The alkylene group preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. Examples of such an alkylene group include a methylene group, an ethylene group, and a propylene group.

The cycloalkylene group as R ₀ preferably has 3 to 10 carbon atoms, and more preferably 5 to 7 carbon atoms. Examples of such a cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, and a cyclohexylene group.

  Each of these alkylene groups and cycloalkylene groups may have a substituent. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom and bromine atom; mercapto group; hydroxy group; alkoxy group of methoxy group, ethoxy group, isopropoxy group, t-butoxy group and benzyloxy group; Cycloalkyl groups such as propyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl; cyano group; nitro group; sulfonyl group; silyl group; ester group; acyl group; vinyl group;

  Z represents an ether bond, an ester bond, an amide bond, a urethane bond or a urea bond as described above. Z is preferably an ether bond or an ester bond, and particularly preferably represents an ester bond.

R ₈ represents a monovalent organic group having a lactone structure as described above. This organic group has, for example, a lactone structure represented by any one of the above general formulas (LC1-1) to (LC1-17). Among these, the structure represented by general formula (LC1-4), (LC1-5) or (LC1-17) is more preferable, and the structure represented by general formula (LC1-4) is particularly preferable.

R ₈ preferably has an unsubstituted lactone structure or a lactone structure having a methyl group, a cyano group, or an alkoxycarbonyl group as a substituent. In particular, R ₈ is preferably a monovalent organic group having a lactone structure having a cyano group as a substituent (that is, a cyanolactone structure).

Specific examples of the repeating unit represented by the general formula (1) are shown below. In the following specific examples, R represents a hydrogen atom, an alkyl group or a halogen atom. This alkyl group may have a substituent. R preferably represents a hydrogen atom, a methyl group, a hydroxymethyl group or an acetoxymethyl group.

The repeating unit represented by the general formula (1) is preferably a repeating unit represented by the following general formula (2).

In general formula (2),
R ₇ , A, R ₀ , Z and n _S have the same _meaning as in general formula (1).
Rb independently represents an alkyl group, a cycloalkyl group, an alkoxycarbonyl group, a cyano group, a hydroxy group, or an alkoxy group when m ≧ 2. When m ≧ 2, two or more Rb may be bonded to each other to form a ring.
X represents an alkylene group, an oxygen atom, or a sulfur atom.
m represents an integer of 0 to 5. m is preferably 0 or 1.

  The alkyl group for Rb is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. Examples of the cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and a t-butoxycarbonyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-butoxy group, and a t-butoxy group. The alkyl group, cycloalkyl group, alkoxycarbonyl group and alkoxy group of Rb may have a substituent. Examples of the substituent include an alkoxy group such as a hydroxy group, a methoxy group and an ethoxy group; a cyano group; and a halogen atom such as a fluorine atom. Rb is more preferably a methyl group, a cyano group or an alkoxycarbonyl group, and even more preferably a cyano group.

  When m ≧ 1, it is preferable that at least one Rb is substituted at the α-position or β-position of the carbonyl group of the lactone. In particular, Rb is preferably substituted at the α-position of the lactone carbonyl group.

  Examples of the alkylene group for X include a methylene group and an ethylene group. X is preferably an oxygen atom or a methylene group, and more preferably a methylene group.

Specific examples of the repeating unit represented by the general formula (2) are shown below. In the following specific examples, R represents a hydrogen atom, an alkyl group or a halogen atom. This alkyl group may have a substituent. R preferably represents a hydrogen atom, a methyl group, a hydroxymethyl group or an acetoxymethyl group.

In order to enhance the effect of the present invention, two or more lactone repeating units selected from general formula (1) can be used in combination. Of formulas (1) when used in combination, it is preferred that n _S to select a combination of two or more kinds of repeating units is 1.

  The content of the repeating unit having a lactone structure is preferably 10 to 80 mol%, more preferably 15 to 70 mol%, and more preferably 20 to 60 mol% with respect to all repeating units in the resin. Further preferred.

  Other preferable repeating units (A) include, for example, a carboxy group, a sulfonamide group, a sulfonylimide group, a bissulfonylimide group, or an aliphatic alcohol group in which the α-position is substituted with an electron withdrawing group (for example, hexafluoro And those having an isopropanol group). This repeating unit (A) more preferably comprises a carboxy group.

  By containing the repeating unit having the above group, the resolution in the contact hole application is increased. Examples of such a repeating unit (A) include a repeating unit in which the above group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or the above main group of the resin through a linking group. Either a repeating unit to which a group is bonded, or a polymerization initiator or chain transfer agent having the above group is introduced at the end of the polymer chain during polymerization, and the linking group is a monocyclic or polycyclic cyclic carbonization. It may have a hydrogen structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

As for the content rate of the repeating unit (A) which has the said group, 0-20 mol% is preferable with respect to all the repeating units in an acid-decomposable resin, More preferably, it is 3-15 mol%, More preferably, it is 5-10 mol%. .
Although the specific example of the repeating unit which has the said group is shown below, this invention is not limited to this.
In specific examples, Rx represents H, CH ₃ , CH ₂ OH, or CF ₃ .

(B) A repeating unit having a group that decomposes by the action of an acid to generate a polar group other than an alcoholic hydroxy group The acid-decomposable resin is a group that decomposes by the action of an acid to generate a polar group other than an alcoholic hydroxy group It is preferable that the repeating unit (B) provided with is further included. In particular, the acid-decomposable resin preferably further includes a repeating unit having a group that decomposes by the action of an acid to generate a carboxy group. In this case, the focus margin (DOF) of the composition containing the acid-decomposable resin can be further improved.

  The repeating unit (B) preferably has a structure in which a polar group is protected by a group that decomposes and leaves by the action of an acid. Examples of the polar group include a phenolic hydroxy group, a carboxy group, a sulfonic acid group, a sulfonamide group, a sulfonylimide group, an (alkylsulfonyl) (alkylcarbonyl) methylene group, an (alkylsulfonyl) (alkylcarbonyl) imide group, Bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group, etc. It is done. Preferred polar groups include a carboxy group and a sulfonic acid group.

A preferable group as the acid-decomposable group is a group in which the hydrogen atom of these polar groups is substituted with a group capable of leaving with an acid.
Examples of the group leaving with an acid include -C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ). ) (OR ₃₉ ) and the like.
In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.

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

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

The repeating unit having an acid-decomposable group that can be contained in the acid-decomposable resin is preferably a repeating unit represented by the following general formula (AI).

In general formula (AI),
Xa ₁ represents a hydrogen atom, a methyl group which may have a substituent, or a group represented by —CH ₂ —R ₉ . R ₉ represents a hydroxy group or a monovalent organic group, and examples thereof include an alkyl group having 5 or less carbon atoms and an acyl group, preferably an alkyl group having 3 or less carbon atoms, and more preferably a methyl group. . Xa ₁ preferably represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

T represents a single bond or a divalent linking group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group (straight or branched) or a cycloalkyl group (monocyclic or polycyclic).
At least two of Rx _{1 to} Rx ₃ may combine to form a cycloalkyl group (monocyclic or polycyclic).

Examples of the divalent linking group for T include an alkylene group, —COO—Rt— group, —O—Rt— group, and the like. In the formula, Rt represents an alkylene group or a cycloalkylene 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 or a — (CH ₂ ) ₃ — group.
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, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group.

Examples of the cycloalkyl group represented by Rx _{1 to} Rx ₃ include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, polycyclic cycloalkyl groups such as norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. Groups are preferred.
Examples of the cycloalkyl group formed by combining at least two of Rx _{1 to} Rx ₃ include a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, A polycyclic cycloalkyl group such as an adamantyl group is preferred. A monocyclic cycloalkyl group having 5 to 6 carbon atoms is particularly preferable.
An embodiment in which Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are combined to form the above-described cycloalkyl group is preferred.

  Each of the above groups may have a substituent, and examples of the substituent include an alkyl group (1 to 4 carbon atoms), a halogen atom, a hydroxy group, an alkoxy group (1 to 4 carbon atoms), and a carboxy group. , Alkoxycarbonyl groups (having 2 to 6 carbon atoms) and the like, and those having 8 or less carbon atoms are preferable.

The acid-decomposable resin preferably has a repeating unit represented by the general formula (I) and / or a repeating unit represented by the general formula (II) as the repeating unit represented by the general formula (AI). .

In formulas (I) and (II),
R ₁ and R ₃ each independently represents a hydrogen atom, an optionally substituted methyl group or a group represented by —CH ₂ —R ₉ . R ₉ represents a monovalent organic group.
R ₂ , R ₄ , R ₅ and R ₆ each independently represents an alkyl group or a cycloalkyl group.
R represents an atomic group necessary for forming an alicyclic structure together with a carbon atom.

R ₁ preferably represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

The alkyl group in R ₂ may be linear or branched, and may have a substituent.

The cycloalkyl group in R ₂ may be monocyclic or polycyclic and may have a substituent.
R ₂ is preferably an alkyl group, more preferably 1 to 10 carbon atoms, still more preferably 1 to 5 carbon atoms, and examples thereof include a methyl group and an ethyl group.

  R represents an atomic group necessary for forming an alicyclic structure together with a carbon atom. The alicyclic structure formed by R is preferably a monocyclic alicyclic structure, and the carbon number thereof is preferably 3 to 7, and more preferably 5 or 6.

R ₃ is preferably a hydrogen atom or a methyl group, more preferably a methyl group.

The alkyl group in R ₄ , R ₅ and R ₆ may be linear or branched and may have a substituent. As the alkyl group, those having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group are preferable.

The cycloalkyl group in R ₄ , R ₅ and R ₆ may be monocyclic or polycyclic and may have a substituent. The cycloalkyl group is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group or an adamantyl group.

As a repeating unit represented by general formula (I), the repeating unit represented by the following general formula (1-a) is mentioned, for example.

In formula, R < ₁ > and R < ₂ > are synonymous with each in general formula (I).

The repeating unit represented by the general formula (II) is more preferably a repeating unit represented by the following general formula (II-1).

In formula (II-1),
R _{3 to} R ₅ have the same meaning as in general formula (II).

R ₁₀ represents a substituent containing a polar group. When a plurality of R ₁₀ are present, they may be the same as or different from each other. Examples of the substituent containing a polar group include a linear or branched alkyl group or cycloalkyl group having a hydroxy group, a cyano group, an amino group, an alkylamide group or a sulfonamido group, and preferably a hydroxy group. It is an alkyl group having As the branched alkyl group, an isopropyl group is particularly preferable.

  p represents an integer of 0 to 15. p is preferably 0 to 2, more preferably 0 or 1.

  The acid-decomposable resin is a resin containing at least one of the repeating unit represented by the general formula (I) and the repeating unit represented by the general formula (II) as the repeating unit represented by the general formula (AI). More preferably. In another embodiment, a resin containing at least two kinds of repeating units represented by the general formula (I) as the repeating unit represented by the general formula (AI) is more preferable.

When the resin of this invention has a repeating unit (B), 3-50 mol% is preferable with respect to all the repeating units in resin, 5-40 mol% is more preferable, and 7-30 mol is the total content. % Is more preferable.
In this case, the molar ratio of the repeating unit (B) to the repeating unit (P) is preferably 5:95 to 70:30, more preferably 7:93 to 50:50, 10 : 90-30: 70 is particularly preferable.

Specific examples of preferred repeating units (B) are shown below, but the present invention is not limited thereto.
In specific examples, Rx and Xa ₁ represent a hydrogen atom, CH ₃ , CF ₃ , or CH ₂ OH. Rxa and Rxb each represents an alkyl group having 1 to 4 carbon atoms. Z represents a substituent containing a polar group, and when there are a plurality of them, each is independent. p represents 0 or a positive integer.

In the case where the acid-decomposable resin contains a plurality of repeating units (B), preferable combinations are as follows. In the following formula, each R independently represents a hydrogen atom or a methyl group.

(C) Repeating unit having an alicyclic hydrocarbon structure not having a polar group and not exhibiting acid decomposability Acid-decomposable resin has an alicyclic hydrocarbon structure having no polar group and has acid decomposability. It may further contain a repeating unit (C) not shown. Examples of the repeating unit (C) include a repeating unit represented by the general formula (IV).

In general formula (IV), R ₅ represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group.
Ra represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group. In the formula, Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group. Ra is preferably a hydrogen atom, a methyl group, a hydroxymethyl group or a trifluoromethyl group, particularly preferably a hydrogen atom or a methyl group.

The cyclic structure possessed by R ₅ includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of the monocyclic hydrocarbon group include a cycloalkenyl group having 3 to 12 carbon atoms such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and the like, and a cycloalkyl group having 3 to 12 carbon atoms and a cyclohexenyl group. Groups. Preferable monocyclic hydrocarbon groups are monocyclic hydrocarbon groups having 3 to 7 carbon atoms, and more preferable examples include a cyclopentyl group and a cyclohexyl group.

The polycyclic hydrocarbon group includes a ring assembly hydrocarbon group and a bridged cyclic hydrocarbon group, and examples of the ring assembly hydrocarbon group include a bicyclohexyl group and a perhydronaphthalenyl group. As the bridged cyclic hydrocarbon ring, for example, bicyclic such as pinane, bornane, norpinane, norbornane, bicyclooctane ring (bicyclo [2.2.2] octane ring, bicyclo [3.2.1] octane ring, etc.) Hydrocarbon rings and tricyclic hydrocarbon rings such as homobredan, adamantane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [4.3.1.1 ^2,5 ] undecane ring, tetracyclo [ 4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, and tetracyclic hydrocarbon rings such as perhydro-1,4-methano-5,8-methanonaphthalene ring. The bridged cyclic hydrocarbon ring includes a condensed cyclic hydrocarbon ring such as perhydronaphthalene (decalin), perhydroanthracene, perhydrophenanthrene, perhydroacenaphthene, perhydrofluorene, perhydroindene, perhydroindene. A condensed ring in which a plurality of 5- to 8-membered cycloalkane rings such as a phenalene ring are condensed is also included.

Preferred examples of the bridged cyclic hydrocarbon ring include a norbornyl group, an adamantyl group, a bicyclooctanyl group, a tricyclo [5,2,1,0 ^2,6 ] decanyl group, and the like. More preferable examples of the bridged cyclic hydrocarbon ring include a norbornyl group and an adamantyl group.

  These alicyclic hydrocarbon groups may have a substituent, and preferred substituents include a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino group protected with a protecting group, and the like. It is done. Preferred halogen atoms include bromine, chlorine and fluorine atoms, and preferred alkyl groups include methyl, ethyl, butyl and t-butyl groups. The above alkyl group may further have a substituent, and the substituent that may further have a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino protected with a protecting group The group can be mentioned.

  Examples of the protecting group include an alkyl group, a cycloalkyl group, an aralkyl group, a substituted methyl group, a substituted ethyl group, an alkoxycarbonyl group, and an aralkyloxycarbonyl group. Preferred alkyl groups include alkyl groups having 1 to 4 carbon atoms, preferred substituted methyl groups include methoxymethyl, methoxythiomethyl, benzyloxymethyl, t-butoxymethyl, 2-methoxyethoxymethyl groups, and preferred substituted ethyl groups. 1-ethoxyethyl, 1-methyl-1-methoxyethyl, preferred acyl groups include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl groups, etc., aliphatic acyl groups having 1 to 6 carbon atoms, alkoxycarbonyl Examples of the group include an alkoxycarbonyl group having 1 to 4 carbon atoms.

As for the content rate of a repeating unit (C), 0-40 mol% is preferable with respect to all the repeating units in an acid-decomposable resin, More preferably, it is 1-20 mol%.
Specific examples of the repeating unit (C) are shown below, but the present invention is not limited thereto. In the formula, Ra represents H, CH ₃ , CH ₂ OH, or CF ₃ .

(D) Other repeating units In addition to the above repeating structural units, the acid-decomposable resin is composed of dry etching resistance, standard developer suitability, substrate adhesion, pattern profile, and actinic ray sensitive or radiation sensitive resin composition. Various repeating structural units can be included for the purpose of adjusting resolution, heat resistance, sensitivity, and the like, which are general necessary characteristics.

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

Thereby, performance required for the resin used in the composition of the present invention, in particular,
(1) Solubility in coating solvent, (2) Film formability (glass transition point), (3) Developability in organic solvent, (4) Film slippage (hydrophobic and polar group selection), (5) Unexposed part Can be finely adjusted such as adhesion to the substrate and (6) dry etching resistance.

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

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

  In addition, in the acid-decomposable resin, the content molar ratio of each repeating structural unit is the dry etching resistance, standard developer suitability, substrate adhesion, pattern profile, and actinic ray sensitive or radiation sensitive resin composition of the composition. It is appropriately set to adjust the resolution, heat resistance, sensitivity, etc., which are general required performances.

When the composition according to the present invention is used for ArF exposure, the acid-decomposable resin preferably has no aromatic group from the viewpoint of transparency to ArF light. In particular, the acid-decomposable resin preferably has a monocyclic or polycyclic alicyclic hydrocarbon structure.
Moreover, it is preferable that an acid-decomposable resin does not contain a fluorine atom and a silicon atom from a compatible viewpoint with the hydrophobic resin mentioned later.

  The acid-decomposable resin is preferably one in which all of the repeating units are composed of (meth) acrylate-based repeating units. In this case, all of the repeating units are methacrylate repeating units, all of the repeating units are acrylate repeating units, or all of the repeating units are methacrylate repeating units and acrylate repeating units. Although it can be used, the acrylate-based repeating unit is preferably 50 mol% or less of the total repeating units.

  When the composition according to the present invention is irradiated with KrF excimer laser light, electron beam, X-ray, high energy light beam (EUV, etc.) having a wavelength of 50 nm or less, the acid-decomposable resin further contains a hydroxystyrene-based repeating unit. It is preferable to have. More preferably, it has a hydroxystyrene-based repeating unit, a hydroxystyrene-based repeating unit protected with an acid-decomposable group, and an acid-decomposable repeating unit such as a (meth) acrylic acid tertiary alkyl ester.

  Examples of the repeating unit having a preferred acid-decomposable group based on hydroxystyrene include, for example, t-butoxycarbonyloxystyrene, 1-alkoxyethoxystyrene, a repeating unit of (meth) acrylic acid tertiary alkyl ester, and the like. More preferred are repeating units of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

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

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

  The weight average molecular weight of the acid-decomposable resin of the present invention is preferably 1,000 to 200,000, more preferably 2,000 to 20,000, still more preferably 3, as a polystyrene conversion value by GPC method. 000 to 15,000, particularly preferably 3,000 to 10,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.

  The dispersity (molecular weight distribution) is usually 1 to 3, preferably 1 to 2.6, more preferably 1 to 2, and particularly preferably 1.4 to 2.0. The smaller the molecular weight distribution, the better the resolution and pattern shape, the smoother the side walls of the pattern, and the better the roughness.

In the present invention, the mixing ratio of the acid-decomposable resin in the entire composition is preferably 30 to 99% by mass, more preferably 60 to 95% by mass in the total solid content.
Moreover, resin may be used by 1 type and may be used together. In this case, two or more kinds of resins containing a repeating unit (P) having a group capable of decomposing by the action of an acid to generate an alcoholic hydroxy group may be used, or repeated within a range not impairing the effects of the present invention. You may use together resin containing the unit (P), and other resin which does not contain the repeating unit (P).

Specific examples of the acid-decomposable resin are shown below. Table 1 below shows the weight average molecular weight (Mw), the degree of dispersion (Mw / Mn), and the composition ratio of each repeating unit (corresponding in order from the left).

(B) Acid generator The composition based on this invention contains the acid generator. As an acid generator, photo-initiator of photocation polymerization, photo-initiator of photo-radical polymerization, photo-decoloring agent of dyes, photo-discoloring agent, or irradiation with actinic ray or radiation used for micro-resist etc. Known compounds that generate acids and mixtures thereof can be appropriately selected and used.

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

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

Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712, etc. can also be used.
Preferred examples of the acid generator include compounds represented by the following general formula (ZI), (ZII) or (ZIII).

In the general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Z ⁻ represents a non-nucleophilic anion.

Examples of the non-nucleophilic anion as Z ⁻ include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

  A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction, and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. Thereby, the temporal stability of the composition is improved.

  Examples of the sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.

  Examples of the carboxylate anion include an aliphatic carboxylate anion, an aromatic carboxylate anion, and an aralkylcarboxylate anion.

  The aliphatic moiety in the aliphatic sulfonate anion may be an alkyl group or a cycloalkyl group, preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms such as methyl. Group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group , Tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, bornyl group and the like.

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

  The alkyl group, cycloalkyl group and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion include, for example, a nitro group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxy group , Hydroxy group, amino group, cyano group, alkoxy group (preferably having 1 to 15 carbon atoms), cycloalkyl group (preferably having 3 to 15 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), alkoxycarbonyl group (Preferably 2 to 7 carbon atoms), acyl group (preferably 2 to 12 carbon atoms), alkoxycarbonyloxy group (preferably 2 to 7 carbon atoms), alkylthio group (preferably 1 to 15 carbon atoms), alkylsulfonyl A group (preferably having a carbon number of 1 to 15), an alkyliminosulfonyl group (preferably having a carbon number of 2 to 15), Reeloxysulfonyl group (preferably having 6 to 20 carbon atoms), alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms), cycloalkylaryloxysulfonyl group (preferably having 10 to 20 carbon atoms), alkyloxyalkyloxy group (Preferably having 5 to 20 carbon atoms), a cycloalkylalkyloxyalkyloxy group (preferably having 8 to 20 carbon atoms), and the like. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) can further be mentioned as a substituent.

As the aromatic sulfonate anion, an aryl sulfonate anion corresponding to the sulfonate represented by the following formula (BI) is also preferable.

In formula (BI),
Ar represents an aromatic ring and may further have a substituent in addition to the A group.
p represents an integer of 0 or more.
A represents a group having a hydrocarbon group having 3 or more carbon atoms.
When p is 2 or more, the plurality of A groups may be the same or different.
General formula (BI) will be described in more detail.
As the aromatic ring represented by Ar, an aromatic ring having 6 to 30 carbon atoms is preferable.
Specifically, benzene ring, naphthalene ring, pentalene ring, indene ring, azulene ring, heptalene ring, indecene ring, perylene ring, pentacene ring, acetaphthalene ring, phenanthrene ring, anthracene ring, naphthacene ring, pentacene ring, chrysene ring, Triphenylene ring, indene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, indolizine Ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole ring, phenanthri Down ring, acridine ring, phenanthroline ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothiazine ring, phenazine ring, and the like, a benzene ring, a naphthalene ring, an anthracene ring are preferred, a benzene ring is more preferable.

  Examples of the substituent that the aromatic ring may have other than the A group include a group having a hydrocarbon group having 1 or more carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), hydroxyl group, A cyano group, a nitro group, a carboxy group, etc. can be mentioned. Examples of the group having a hydrocarbon group having 1 or more carbon atoms include an alkoxy group such as a methoxy group, an ethoxy group, and a tert-butoxy group, an aryloxy group such as a phenoxy group and a p-tolyloxy group, a methylthioxy group, Alkylthioxy groups such as ethylthioxy group, tert-butylthioxy group, arylthioxy groups such as phenylthioxy group, p-tolylthioxy group, alkoxycarbonyl groups such as methoxycarbonyl group, butoxycarbonyl group, phenoxycarbonyl group, acetoxy group, methyl Group, ethyl group, propyl group, butyl group, heptyl group, hexyl group, dodecyl group, linear alkyl group such as 2-ethylhexyl group and branched alkyl group, alkenyl group such as vinyl group, propenyl group, hexenyl group, acetylene group , Propynyl group, hexynyl group, etc. Rukiniru group, aryl groups such as phenyl and tolyl groups, a benzoyl group, an acetyl group, and the like acyl groups such as tolyl group. Moreover, when it has two or more substituents, at least two substituents may be bonded to each other to form a ring.

Examples of the hydrocarbon group in the group having a hydrocarbon group having 3 or more carbon atoms represented by A include an acyclic hydrocarbon group and a cyclic aliphatic group.
As the A group, the carbon atom adjacent to Ar is preferably a tertiary or quaternary carbon atom.
Examples of the acyclic hydrocarbon group as the A group include isopropyl group, t-butyl group, t-pentyl group, neopentyl group, s-butyl group, isobutyl group, isohexyl group, 3,3-dimethylpentyl group, 2- An ethylhexyl group etc. are mentioned. The upper limit of the number of carbon atoms of the acyclic hydrocarbon group is preferably 12 or less, more preferably 10 or less.

  Examples of the cycloaliphatic group as the A group include a cycloalkyl group such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantyl group, a norbornyl group, a bornyl group, a camphenyl group, and a decahydronaphthyl group , Tricyclodecanyl group, tetracyclodecanyl group, camphoroyl group, dicyclohexyl group, pinenyl group and the like, which may have a substituent. The upper limit of the carbon number of the cycloaliphatic group is preferably 15 or less, more preferably 12 or less.

When the acyclic hydrocarbon group or the cyclic aliphatic group has a substituent, examples of the substituent include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a methoxy group, and an ethoxy group. Group, alkoxy group such as tert-butoxy group, aryloxy group such as phenoxy group, p-tolyloxy group, alkylthioxy group such as methylthioxy group, ethylthioxy group, tert-butylthioxy group, phenylthioxy group, p-tolyloxy group Arylthiooxy group such as methoxycarbonyl group, butoxycarbonyl group, phenoxycarbonyl group, etc., acetoxy group, methyl group, ethyl group, propyl group, butyl group, heptyl group, hexyl group, dodecyl group, 2- Linear alkyl groups such as ethylhexyl group, branched alkyl groups, A cyclic alkyl group such as a rohexyl group, an alkenyl group such as a vinyl group, a propenyl group and a hexenyl group, an alkynyl group such as an acetylene group, a propynyl group and a hexynyl group, an aryl group such as a phenyl group and a tolyl group, a hydroxy group, a carboxy group, Examples include a sulfonic acid group, a carbonyl group, and a cyano group.
Specific examples of the cyclic aliphatic group or acyclic hydrocarbon group as A include the following.

Among the above, the following structures are more preferable from the viewpoint of suppressing acid diffusion.

  p represents an integer of 0 or more, and the upper limit is not particularly limited as long as it is a chemically possible number. From the viewpoint of suppressing acid diffusion, p is usually 0 to 5, preferably 1 to 4, more preferably 2 to 3, and most preferably 3.

From the viewpoint of suppressing acid diffusion, the A group preferably has at least one ortho position (o position) of the sulfonic acid group substituted, and has a structure in which two ortho positions (o position) are substituted. Is more preferable.
In one embodiment, the acid generator is a compound that generates an acid represented by the following general formula (BII).

In the formula, A is the same as A in the general formula (BI), and two A may be the same or different. R _{1 to} R ₃ each independently represents a hydrogen atom, a group having a hydrocarbon group having 1 or more carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. Specific examples of the hydrocarbon group having 1 or more carbon atoms include the same groups as those exemplified above.

Moreover, the anion which produces the acid represented with the following general formula (IA) as a preferable sulfonate anion can also be mentioned.

In the formula, each Xf independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. R ¹ and R ² each independently represents a hydrogen atom, a fluorine atom, an alkyl group, or a group selected from an alkyl group substituted with at least one fluorine atom, and R ¹ and R ² in the case where a plurality of R ¹ and R ^{2 are present.} May be the same or different. L represents a single bond or a divalent linking group, and when there are a plurality of L, they may be the same or different. A represents a group having a cyclic structure. 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.

General formula (IA) is demonstrated in detail.
The alkyl group in the alkyl group substituted with the fluorine atom of Xf preferably has 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. 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. Specifically, a fluorine atom and CF ₃ are preferable.

The alkyl group in R ¹ and R ^{2 and} the alkyl group substituted with at least one fluorine atom are preferably those having 1 to 4 carbon atoms. More preferably, it is a C1-C4 perfluoroalkyl group. Specifically, CF ₃ is preferable.

y is preferably 0 to 4, and more preferably 0. x is preferably from 1 to 8, and preferably from 1 to 4. z is preferably 0 to 8, particularly preferably 0 to 4. The divalent linking group of L is not particularly limited, and is —COO—, —OCO—, —CO—, —O—, —S—, —SO—, —SO ₂ —, an alkylene group, a cycloalkylene group, Examples include alkenylene groups. Among these, —COO—, —OCO—, —CO—, —O—, and —SO ₂ — are preferable, and —COO—, —OCO—, and —SO ₂ — are more preferable.

  The group having a cyclic structure of A is not particularly limited as long as it has a cyclic structure. The group having an alicyclic group, an aryl group, or a heterocyclic structure (not only those having an aromatic attribute, but also having an aromatic attribute). And the like).

  The alicyclic group may be monocyclic or polycyclic, and may be a monocyclic cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, or a cyclooctyl group, a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, or a tetracyclododecane group. A polycyclic cycloalkyl group such as a nyl group and an adamantyl group is preferred. Among them, an alicyclic group having a bulky structure having 7 or more carbon atoms such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group is used in the PEB (post-exposure heating) step. It is preferable from the viewpoint of improving MEEF (mask error enhancement factor) because diffusibility in the film can be suppressed.

  Examples of the aryl group include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. Of these, naphthalene having low absorbance is preferred from the viewpoint of light absorbance at 193 nm.

  Examples of the group having a heterocyclic structure include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, a pyridine ring, and a piperidine ring. Of these, a furan ring, a thiophene ring, a pyridine ring, and a piperidine ring are preferable. Further, the heterocyclic structure may be a ring structure having a lactone structure.

  The group having the cyclic structure may have a substituent, and the substituent may be an alkyl group (which may be linear, branched or cyclic, preferably having 1 to 12 carbon atoms), Examples thereof include an aryl group (preferably having 6 to 14 carbon atoms), a hydroxyl group, an alkoxy group, an ester group, an amide group, a urethane group, a ureido group, a thioether group, a sulfonamide group, and a sulfonic acid ester group.

  Examples of the aliphatic moiety in the aliphatic carboxylate anion include the same alkyl group and cycloalkyl group as in the aliphatic sulfonate anion.

  Examples of the aromatic group in the aromatic carboxylate anion include the same aryl group as in the aromatic sulfonate anion.

  The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 6 to 12 carbon atoms, such as benzyl group, phenethyl group, naphthylmethyl group, naphthylethyl group, naphthylbutyl group, and the like.

  The alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion include, for example, the same halogen atom and alkyl as in the aromatic sulfonate anion Group, cycloalkyl group, alkoxy group, alkylthio group and the like.

  Examples of the sulfonylimide anion include saccharin anion.

  The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methide anion is preferably an alkyl group having 1 to 5 carbon atoms, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl. Group, sec-butyl group, pentyl group, neopentyl group and the like. Examples of substituents for these alkyl groups include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, cycloalkylaryloxysulfonyl groups, and the like. Alkyl groups substituted with fluorine atoms are preferred.

  Examples of other non-nucleophilic anions include fluorinated phosphorus, fluorinated boron, and fluorinated antimony.

Examples of the organic group represented by R ₂₀₁ , R ₂₀₂ and R ₂₀₃ in the general formula (ZI) include, for example, a compound (ZI-1), (ZI-2), (ZI-3) or (ZI-4) described later. The corresponding groups can be mentioned.

The acid generator may be a compound having a plurality of structures represented by the general formula (ZI). For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (ZI), the structures attached to at least one of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (ZI) It may be a compound.

  More preferred (ZI) components include compounds (ZI-1), (ZI-2), (ZI-3) and (ZI-4) described below.

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compounds, namely, compounds containing an arylsulfonium as a cation.

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

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

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the heterocyclic structure include pyrrole, furan, thiophene, indole, benzofuran, benzothiophene, and the like. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

  The alkyl group or cycloalkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, such as a methyl group, Examples thereof include an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxy group, or a phenylthio group may be used as a substituent. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, more preferably carbon. These are an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

  Next, the compound (ZI-2) will be described.

Compound (ZI-2) is a compound in which R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.

The alkyl group and cycloalkyl group of R ₂₀₁ to R _203, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group). More preferred examples of the alkyl group include a 2-oxoalkyl group and an alkoxycarbonylmethyl group. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl group.

  The 2-oxoalkyl group may be either linear or branched, and a group having> C = O at the 2-position of the above alkyl group is preferable.

  The 2-oxocycloalkyl group is preferably a group having> C═O at the 2-position of the cycloalkyl group.

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

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxy group, a cyano group, or a nitro group.

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

In general formula (ZI-3),
R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a halogen atom or a phenylthio group.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an aryl group.
R _x and R _y each independently represents an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group.

Any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom and a sulfur atom. , An ester bond and an amide bond may be included. Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

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

The alkyl group as R _{1c to} R _7c may be either linear or branched, for example, an alkyl group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms ( Examples thereof include a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, and a linear or branched pentyl group. Examples of the cycloalkyl group include cyclohexane having 3 to 8 carbon atoms. An alkyl group (for example, a cyclopentyl group, a cyclohexyl group) can be mentioned.

The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).

Preferably, any of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c. Is 2-15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

The aryl group as R _6c and R _7c preferably has 5 to 15 carbon atoms, and examples thereof include a phenyl group and a naphthyl group.

When R _6c and R _7c are combined to form a ring, the group formed by combining R _6c and R _7c is preferably an alkylene group having 2 to 10 carbon atoms, such as ethylene group, propylene Group, butylene group, pentylene group, hexylene group and the like. The ring formed by combining R _6c and R _7c may have a hetero atom such as an oxygen atom in the ring.

_Examples of the alkyl group and cycloalkyl group as R _x and R _y include the same alkyl group and cycloalkyl group as in R _{1c to} R _7c .

Examples of the 2-oxoalkyl group and 2-oxocycloalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .
Examples of the alkoxy group in the alkoxycarbonylalkyl group include the same alkoxy groups as in R _{1c to} R _5c , and examples of the alkyl group include an alkyl group having 1 to 12 carbon atoms, preferably 1 to 1 carbon atom. 5 straight chain (for example, methyl group and ethyl group).

  The allyl group is not particularly limited, but is preferably an allyl group which is unsubstituted or substituted with a monocyclic or polycyclic cycloalkyl group.

  Although there is no restriction | limiting in particular as a vinyl group, It is preferable that it is a vinyl group substituted by the unsubstituted or monocyclic or polycyclic cycloalkyl group.

As the ring structure that R _x and R _y may be bonded to each other, divalent R _x and R _y (for example, a methylene group, an ethylene group, a propylene group, and the like) are represented by the general formula (ZI-3). A 5-membered or 6-membered ring formed with a sulfur atom, particularly preferably a 5-membered ring (that is, a tetrahydrothiophene ring).

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

Specific examples of the cation moiety of compound (ZI-3) are shown below.

The compound (ZI-4) is a compound represented by the following general formula (ZI-4).

In general formula (ZI-4),
R ₁₃ represents a hydrogen atom, a fluorine atom, a hydroxy group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a group having a monocyclic or polycyclic cycloalkyl skeleton. These groups may have a substituent.

When there are a plurality of R _{14 s,} each independently represents an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a monocyclic or polycyclic cycloalkyl skeleton. Represents a group having These groups may have a substituent.

R ₁₅ each independently represents an alkyl group, a cycloalkyl group or a naphthyl group. Two R ₁₅ may be bonded to each other to form a ring. These groups may have a substituent.

  l represents an integer of 0-2.

  r represents an integer of 0 to 8.

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

In the general formula (ZI-4), the alkyl group of R ₁₃ , R ₁₄ and R ₁₅ is linear or branched and preferably has 1 to 10 carbon atoms, and is preferably a methyl group, an ethyl group, n -Propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n -An octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group etc. can be mentioned. Of these alkyl groups, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, and the like are preferable.

Examples of the cycloalkyl group represented by R ₁₃ , R ₁₄ and R ₁₅ include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclododecanyl, cyclopentenyl, cyclohexenyl, cyclooctadienyl, norbornyl, tricyclo Examples include decanyl, tetracyclodecanyl, adamantyl and the like, and cyclopropyl, cyclopentyl, cyclohexyl and cyclooctyl are particularly preferable.

The alkoxy group of R ₁₃ and R ₁₄ is linear or branched and preferably has 1 to 10 carbon atoms, such as methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n -Butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group and the like can be mentioned. Of these alkoxy groups, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, and the like are preferable.

The alkoxycarbonyl group for R ₁₃ and R ₁₄ is linear or branched and preferably has 2 to 11 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, i- Propoxycarbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, Examples include n-heptyloxycarbonyl group, n-octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group and the like. Of these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

Examples of the group having a monocyclic or polycyclic cycloalkyl skeleton of R ₁₃ and R ₁₄ include a monocyclic or polycyclic cycloalkyloxy group and an alkoxy group having a monocyclic or polycyclic cycloalkyl group. Can be mentioned. These groups may further have a substituent.

The monocyclic or polycyclic cycloalkyloxy group for R ₁₃ and R ₁₄ preferably has a total carbon number of 7 or more, more preferably a total carbon number of 7 or more and 15 or less, It is preferable to have a cycloalkyl skeleton. The monocyclic cycloalkyloxy group having 7 or more carbon atoms is cyclopropyloxy group, cyclobutyloxy group, cyclopentyloxy group, cyclohexyloxy group, cycloptyloxy group, cyclooctyloxy group, cyclododecanyloxy group, etc. Optionally substituted with methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, dodecyl, 2-ethylhexyl, isopropyl, sec-butyl, t -Alkyl group such as butyl group and iso-amyl group, hydroxy group, halogen atom (fluorine, chlorine, bromine, iodine), nitro group, cyano group, amide group, sulfonamido group, methoxy group, ethoxy group, hydroxyethoxy group , Alkoxy groups such as propoxy group, hydroxypropoxy group, butoxy group, meth Monocyclic cycloalkyloxy having substituents such as alkoxycarbonyl groups such as xoxycarbonyl group, ethoxycarbonyl group, acyl groups such as formyl group, acetyl group and benzoyl group, acyloxy groups such as acetoxy group and butyryloxy group, and carboxy group And a group having a total carbon number of 7 or more in combination with an arbitrary substituent on the cycloalkyl group.

  Examples of the polycyclic cycloalkyloxy group having a total carbon number of 7 or more include a norbornyloxy group, a tricyclodecanyloxy group, a tetracyclodecanyloxy group, an adamantantyloxy group, and the like.

The alkoxy group having a monocyclic or polycyclic cycloalkyl skeleton of R ₁₃ and R ₁₄ preferably has a total carbon number of 7 or more, more preferably a total carbon number of 7 or more and 15 or less, An alkoxy group having a monocyclic cycloalkyl skeleton is preferable. The alkoxy group having a total of 7 or more carbon atoms and having a monocyclic cycloalkyl skeleton is methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptoxy, octyloxy, dodecyloxy, 2-ethylhexyloxy, isopropoxy, A monocyclic cycloalkyl group that may have the above-mentioned substituents is substituted on an alkoxy group such as sec-butoxy, t-butoxy, iso-amyloxy, etc., and the total carbon number including the substituents is 7 or more Represents things. Examples include a cyclohexylmethoxy group, a cyclopentylethoxy group, a cyclohexylethoxy group, and the like, and a cyclohexylmethoxy group is preferable.

  Examples of the alkoxy group having a polycyclic cycloalkyl skeleton having 7 or more carbon atoms include norbornyl methoxy group, norbornyl ethoxy group, tricyclodecanyl methoxy group, tricyclodecanyl ethoxy group, tetracyclo A decanyl methoxy group, a tetracyclodecanyl ethoxy group, an adamantane methoxy group, an adamantane ethoxy group, etc. are mentioned, and a norbornyl methoxy group, a norbornyl ethoxy group, etc. are preferable.

The alkyl group of the alkyl group of R ^14, include the same specific examples as the alkyl group as R ₁₃ to R ₁₅ described above.

The alkylsulfonyl group and cycloalkylsulfonyl group of R ₁₄ are linear, branched, or cyclic, and preferably those having 1 to 10 carbon atoms, such as methanesulfonyl group, ethanesulfonyl group, n-propanesulfonyl. Group, n-butanesulfonyl group, tert-butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group n -Nonanesulfonyl group, n-decanesulfonyl group, cyclopentanesulfonyl group, cyclohexanesulfonyl group, etc. can be mentioned. Of these alkylsulfonyl groups and cycloalkylsulfonyl groups, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, and the like are preferable.

  Examples of the substituent that each of the above groups may have include a halogen atom (for example, a fluorine atom), a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkoxy group, an alkoxyalkyl group, an alkoxycarbonyl group, and alkoxycarbonyloxy. Groups and the like.

  Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, cyclopentyloxy group, Examples thereof include a linear, branched or cyclic alkoxy group having 1 to 20 carbon atoms such as a cyclohexyloxy group.

  Examples of the alkoxyalkyl group include straight chain having 2 to 21 carbon atoms such as methoxymethyl group, ethoxymethyl group, 1-methoxyethyl group, 2-methoxyethyl group, 1-ethoxyethyl group, and 2-ethoxyethyl group. Examples thereof include a chain, branched or cyclic alkoxyalkyl group.

  Examples of the alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, i-propoxycarbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t Examples thereof include linear, branched or cyclic alkoxycarbonyl groups having 2 to 21 carbon atoms such as butoxycarbonyl group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl and the like.

  Examples of the alkoxycarbonyloxy group include methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, i-propoxycarbonyloxy group, n-butoxycarbonyloxy group, t-butoxycarbonyloxy group, and cyclopentyloxy. Examples thereof include linear, branched or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms such as carbonyloxy group and cyclohexyloxycarbonyloxy.

The ring structure which two R ₁₅ may combine with each other is a 5-membered or 6-membered ring formed by two divalent R ₁₅ together with the sulfur atom in the general formula (ZI-4). Particularly preferred is a 5-membered ring (that is, a tetrahydrothiophene ring), which may be condensed with an aryl group or a cycloalkyl group. The divalent R ₁₅ may have a substituent. Examples of the substituent include a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkoxy group, an alkoxyalkyl group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, and the like. Groups and the like. R ₁₅ in the general formula (ZI-4) is preferably a methyl group, an ethyl group, a naphthyl group, a divalent group in which two R ^15s are bonded to each other to form a tetrahydrothiophene ring structure together with a sulfur atom.

The substituent that R ₁₃ and R ₁₄ may have is preferably a hydroxy group, an alkoxy group, an alkoxycarbonyl group, or a halogen atom (particularly a fluorine atom).

l is preferably 0 or 1, and more preferably 1.
As r, 0-2 are preferable.

Specific examples of the cation moiety of compound (ZI-4) are given below.

Next, the general formulas (ZII) and (ZIII) will be described.
In formula (ZII), (ZIII), R 204 ~R 207 each independently represents an aryl group, an alkyl group or a cycloalkyl group.

Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group. Aryl group R ₂₀₄ to R ₂₀₇ represents an oxygen atom, a nitrogen atom, may be an aryl group having a heterocyclic structure having a sulfur atom and the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like.

The alkyl group and cycloalkyl group in R _{204 to} R ₂₀₇ are preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).

Aryl group, alkyl group of R ₂₀₄ to R _207, cycloalkyl groups may have a substituent. Aryl group, alkyl group of R ₂₀₄ to R _207, the cycloalkyl group substituent which may be possessed by, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms ), An aryl group (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxy group, and a phenylthio group.

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

Examples of the acid generator further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI).

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

R ₂₀₈ , R ₂₀₉ and R ₂₁₀ each independently represents an alkyl group, a cycloalkyl group or an aryl group.

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

  Among the acid generators, compounds represented by the general formulas (ZI) to (ZIII) are more preferable.

  Further, the acid generator is preferably a compound that generates an acid having one sulfonic acid group or imide group, more preferably a compound that generates monovalent perfluoroalkanesulfonic acid, or a monovalent fluorine atom or fluorine atom. A compound that generates an aromatic sulfonic acid substituted with a group that contains a monovalent fluorine atom or an imido acid that is substituted with a group containing a fluorine atom, and even more preferably, a fluorinated compound It is a sulfonium salt of a substituted alkanesulfonic acid, a fluorine-substituted benzenesulfonic acid, a fluorine-substituted imide acid or a fluorine-substituted methide acid. The acid generator that can be used is particularly preferably a fluorinated substituted alkane sulfonic acid, a fluorinated substituted benzene sulfonic acid or a fluorinated substituted imido acid whose pKa of the generated acid is pKa = -1 or less, and the sensitivity is improved. .

  As the acid generator, a carboxylic acid onium salt may be used. When carboxylic acid onium salt is contained, transparency to light having a wavelength of 220 nm or less is ensured, sensitivity and resolution are further improved, and density dependency and exposure margin are further improved.

  As the carboxylic acid onium salt, an iodonium salt or a sulfonium salt is preferable. As the anion, for example, a linear or branched alkyl having 1 to 30 carbon atoms or a monocyclic or polycyclic cycloalkylcarboxylic acid anion is preferably used. In particular, a carboxylate anion in which some or all of the hydrogen atoms of these alkyl groups or cycloalkyl groups are substituted with fluorine atoms (hereinafter also referred to as fluorine-substituted carboxylate anions) is preferable. Note that an oxygen atom may be contained in the alkyl or cycloalkyl chain.

  Examples of the fluorine-substituted carboxylate anion include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorocyclohexanecarboxylic acid, and 2 , 2-bistrifluoromethylpropionic acid anion.

  When the composition according to the present invention contains a carboxylic acid onium salt, the content thereof is generally from 0.1 to 20% by mass, preferably from 0.8 to 20% by mass, based on the total solid content of the composition. It is 5-10 mass%, More preferably, it is 1-7 mass%.

  When the composition according to the present invention contains an acid generator, the acid that can be generated by the acid generator may or may not have a fluorine atom. For example, when the acid generator includes an anion, the anion may have a fluorine atom or may not have a fluorine atom.

  As described above, the composition according to the present invention contains a resin containing a repeating unit having a group that decomposes by the action of an acid to generate an alcoholic hydroxy group. Such a resin is a repeating unit having an acid-decomposable group, as compared with a resin containing only a repeating unit having a group that decomposes by the action of an acid to generate a carboxy group. The activation energy of is smaller. Therefore, even when an acid generator that generates an acid with relatively low acid strength, for example, an acid having no fluorine atom, is used, the effects of the present invention can be sufficiently obtained.

Among acid generators, particularly preferred examples are given below.

An acid generator can be used individually by 1 type or in combination of 2 or more types.
The content of the acid generator is preferably 0.1 to 20% by mass, more preferably 0.5 to 17.5% by mass, still more preferably 1 to 15% by mass, based on the total solid content of the composition. is there.

(C) Hydrophobic resin The composition according to the present invention contains a hydrophobic resin. By including the hydrophobic resin, the hydrophobic resin is unevenly distributed in the surface layer of the composition film, and it becomes possible to improve the receding contact angle of the film with respect to the immersion liquid when water is used as the immersion medium. Thereby, the immersion liquid followability of a film | membrane can be improved. This also provides the effect of improving immersion defects called bubble defects and water residue defects that occur with immersion exposure.

  In addition, when performing development using a developer containing an organic solvent, the present inventors can significantly improve development defect performance, limit resolving power, and pattern shape by including a hydrophobic resin in the composition. Is heading. The present inventors presume that this effect is attributed to the improved solubility in the vicinity of the surface of the composition film in the developer due to the addition of the hydrophobic resin. This effect is also remarkable when an exposure method other than the immersion exposure method is employed.

The receding contact angle of the film after baking and before exposure is preferably 60 ° to 90 ° at a temperature of 23 ± 3 ° C. and a humidity of 45 ± 5%, more preferably 65 ° or more, still more preferably 70 ° or more, and particularly preferably. It is 75 ° or more.
The hydrophobic resin is unevenly distributed at the interface as described above, but unlike the surfactant, it does not necessarily have a hydrophilic group in the molecule and contributes to uniform mixing of polar / nonpolar substances. It is not necessary.

  In the immersion exposure process, the immersion head needs to move on the wafer following the movement of the exposure head to scan the wafer at high speed to form the exposure pattern. The contact angle of the immersion liquid with respect to the film in the film becomes important, and the actinic ray-sensitive or radiation-sensitive resin composition is required to follow the high-speed scanning of the exposure head without leaving droplets.

  The hydrophobic resin typically contains at least one of a fluorine atom and a silicon atom. The fluorine atom or silicon atom in the hydrophobic resin may be present in the main chain of the resin or may be substituted on the side chain. When the hydrophobic resin has at least one of a fluorine atom and a silicon atom, the hydrophobicity (water followability) of the film surface is improved, and a remarkable development defect improving effect is exhibited in the solvent development system.

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

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

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

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

Preferred examples of the alkyl group having a fluorine atom, the cycloalkyl group having a fluorine atom, or the aryl group having a fluorine atom include groups represented by the following general formulas (F2) to (F4). The present invention is not limited to this.

In general formulas (F2) to (F4),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{57 to} R ₆₁ , R _{62 to} R ₆₄ and R _{65 to} R ₆₈ is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having 1 carbon atom). ~ 4). R _{57 to} R ₆₁ and R _{65 to} R ₆₇ are preferably all fluorine atoms. R ₆₂ , R ₆₃ and R ₆₈ are preferably an alkyl group (preferably having 1 to 4 carbon atoms) in which at least one hydrogen atom is substituted with a fluorine atom, and preferably a perfluoroalkyl group having 1 to 4 carbon atoms. Further preferred. R ₆₂ and R ₆₃ may be connected to each other to form a ring.

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

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

Specific examples of the group represented by the general formula (F4) include, for example, —C (CF ₃ ) ₂ OH, —C (C ₂ F ₅ ) ₂ OH, —C (CF ₃ ) (CH ₃ ) OH, -CH (CF ₃₎ OH and the like, -C (CF _{3) 2} OH is preferred.

Suitable examples of the repeating unit having a fluorine atom include those shown below.

In the formula, R ₁₀ and R ₁₁ are each independently a hydrogen atom, a fluorine atom, or an alkyl group (preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and particularly as an alkyl group having a substituent, Fluorinated alkyl group can be mentioned).
W _{3 to} W ₆ each independently represents an organic group containing at least one fluorine atom. Specific examples include groups represented by the general formulas (F2) to (F4).
Moreover, you may have a unit as shown below as a repeating unit which has a fluorine atom besides these.

In the formula, R _{4 to} R ₇ are each independently a hydrogen atom, a fluorine atom, or an alkyl group (preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and the alkyl group having a substituent is In particular, a fluorinated alkyl group can be mentioned).

However, at least one of R _{4 to} R ₇ represents a fluorine atom. R ₄ and R ₅ or R ₆ and R ₇ may form a ring.
W ₂ represents an organic group containing at least one fluorine atom. Specific examples include the atomic groups (F2) to (F4).

  Q represents an alicyclic structure. The alicyclic structure may have a substituent and may be monocyclic or polycyclic. In the case of a polycyclic type, a bridge type may be used. As the monocyclic type, a cycloalkyl group having 3 to 8 carbon atoms is preferable, and examples thereof include a cyclopentyl group, a cyclohexyl group, a cyclobutyl group, and a cyclooctyl group. Examples of the polycyclic type include groups having a bicyclo, tricyclo or tetracyclo structure having 5 or more carbon atoms, and a cycloalkyl group having 6 to 20 carbon atoms is preferable, for example, an adamantyl group, norbornyl group, dicyclopentyl group. , Tricyclodecanyl group, tetocyclododecyl group and the like. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.

L ₂ represents a single bond or a divalent linking group. Examples of the divalent linking group include a substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, —O—, —SO ₂ —, —CO—, —N (R )-(Wherein R represents a hydrogen atom or an alkyl group), —NHSO ₂ — or a divalent linking group formed by combining a plurality of these.
The hydrophobic resin may contain a silicon atom. The partial structure having a silicon atom is preferably a resin having an alkylsilyl structure (preferably a trialkylsilyl group) or a cyclic siloxane structure.

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

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents a linear or branched alkyl group (preferably having 1 to 20 carbon atoms) or a cycloalkyl group (preferably having 3 to 20 carbon atoms).
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group. As the divalent linking group, an alkylene group, a phenylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group, or a urea group is used alone or in combination of two or more groups. A combination is mentioned.
n represents an integer of 1 to 5. n is preferably an integer of 2 to 4.
Specific examples of the repeating unit containing a fluorine atom or a silicon atom are shown below. In specific examples, X ₁ represents a hydrogen atom, —CH ₃ , —F or —CF ₃ , and X ₂ represents —F or —CF ₃ .

Furthermore, the hydrophobic resin may have at least one group selected from the following (x) and (y).
(X) a polar group;
(Y) A group (acid-decomposable group) that is decomposed by the action of an acid.

(X) As a polar group, phenolic hydroxy group, carboxy group, sulfonic acid group, sulfonamide group, sulfonylimide group, (alkylsulfonyl) (alkylcarbonyl) methylene group, (alkylsulfonyl) (alkylcarbonyl) imide group, Bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group, etc. It is done.
Preferred polar groups include a carboxy group, a sulfonimide group, and a bis (carbonyl) methylene group. In particular, when the hydrophobic resin contains a repeating unit having a carboxy group, the development defect performance can be further improved.

  As the repeating unit having a polar group (x), a repeating unit in which a polar group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or the main chain of the resin through a linking group Examples thereof include a repeating unit to which a polar group is bonded. Further, a polymerization initiator or a chain transfer agent having a polar group can be introduced at the end of the polymer chain at the time of polymerization, and any case is preferable.

  The content of the repeating unit having a polar group (x) is preferably 1 to 30 mol%, more preferably 1.5 to 20 mol%, still more preferably 2 to 10 mol%, based on all repeating units in the hydrophobic resin. is there.

Specific examples of the repeating unit having a polar group (x) are shown below. In specific examples, Rx represents H, CH ₃ , CH ₂ OH, or CF ₃ .

Examples of the repeating unit having a group (y) that is decomposed by the action of an acid in the hydrophobic resin include the same repeating units having an acid-decomposable group as mentioned above for the acid-decomposable resin.
In the hydrophobic resin, the content of the repeating unit having a group (y) that is decomposed by the action of an acid is preferably 0 to 80 mol%, more preferably 0 to 50 mol based on all repeating units in the hydrophobic resin. %, More preferably 0 to 20 mol%. In particular, the limiting resolution can be further improved by setting the content to 20 mol% or less.

The hydrophobic resin may further have a repeating unit represented by the following general formula (VI).

In general formula (VI):
R _c31 represents a hydrogen atom, an alkyl group _optionally substituted with fluorine, a cyano group, or a —CH ₂ —O—Rac ₂ group. Wherein, Rac ₂ represents a hydrogen atom, an alkyl group or an acyl group. R _c31 is preferably a hydrogen atom, a methyl group, a hydroxymethyl group or a trifluoromethyl group, particularly preferably a hydrogen atom or a methyl group.
R _c32 represents a group having an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an aryl group. These groups may be substituted with a fluorine atom or a silicon atom.
L _c3 represents a single bond or a divalent linking group.

In general formula (VI), the alkyl group represented by R _c32 is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
The aryl group is preferably a phenyl group or naphthyl group having 6 to 20 carbon atoms, and these may have a substituent.

R _c32 is preferably an unsubstituted alkyl group or an alkyl group substituted with a fluorine atom.
The divalent linking group of L _c3 is preferably an alkylene group (preferably having 1 to 5 carbon atoms), an oxy group, a phenylene group, or an ester bond (a group represented by —COO—).
The hydrophobic resin may contain a repeating unit represented by the following general formula (VII) or (VIII) as the repeating unit represented by the general formula (VI).

In general formula (VII), R _c5 represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxy group nor a cyano group.
Rac represents a hydrogen atom, an alkyl group which may be substituted with a fluorine atom, a cyano group or a —CH ₂ —O—Rac ₂ group. Wherein, Rac ₂ represents a hydrogen atom, an alkyl group or an acyl group. Rac is preferably a hydrogen atom, a methyl group, a hydroxymethyl group or a trifluoromethyl group, particularly preferably a hydrogen atom or a methyl group.

The cyclic structure possessed by R _c5 includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of the monocyclic hydrocarbon group include a cycloalkyl group having 3 to 12 carbon atoms and a cycloalkenyl group having 3 to 12 carbon atoms. A preferable monocyclic hydrocarbon group is a monocyclic hydrocarbon group having 3 to 7 carbon atoms.

  The polycyclic hydrocarbon group includes a ring assembly hydrocarbon group and a bridged cyclic hydrocarbon group. Examples of the bridged cyclic hydrocarbon ring include a bicyclic hydrocarbon ring, a tricyclic hydrocarbon ring, and a tetracyclic hydrocarbon ring. The bridged cyclic hydrocarbon ring also includes a condensed cyclic hydrocarbon ring (for example, a condensed ring in which a plurality of 5- to 8-membered cycloalkane rings are condensed). Preferred examples of the bridged cyclic hydrocarbon ring include a norbornyl group and an adamantyl group.

  These alicyclic hydrocarbon groups may have a substituent, and preferred substituents include a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino group protected with a protecting group, and the like. It is done. Preferred halogen atoms include bromine, chlorine and fluorine atoms, and preferred alkyl groups include methyl, ethyl, butyl and t-butyl groups. The above alkyl group may further have a substituent, and the substituent that may further have a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino protected with a protecting group The group can be mentioned.

  Examples of the protecting group include an alkyl group, a cycloalkyl group, an aralkyl group, a substituted methyl group, a substituted ethyl group, an alkoxycarbonyl group, and an aralkyloxycarbonyl group. Preferred alkyl groups include alkyl groups having 1 to 4 carbon atoms, preferred substituted methyl groups include methoxymethyl, methoxythiomethyl, benzyloxymethyl, t-butoxymethyl, 2-methoxyethoxymethyl groups, and preferred substituted ethyl groups. 1-ethoxyethyl, 1-methyl-1-methoxyethyl, preferred acyl groups include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl groups, etc., aliphatic acyl groups having 1 to 6 carbon atoms, alkoxycarbonyl Examples of the group include an alkoxycarbonyl group having 1 to 4 carbon atoms.

In the general formula (VIII), R _c6 represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkoxycarbonyl group, or an alkylcarbonyloxy group. These groups may be substituted with a fluorine atom or a silicon atom.
The alkyl group for R _c6 is preferably a linear or branched alkyl group having 1 to 20 carbon atoms.

The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
The alkoxycarbonyl group is preferably an alkoxycarbonyl group having 2 to 20 carbon atoms.

The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 20 carbon atoms.
n represents an integer of 0 to 5. When n is 2 or more, the plurality of R _c6 may be the same or different.
R _c6 is preferably an unsubstituted alkyl group or an alkyl group substituted with a fluorine atom, particularly preferably a trifluoromethyl group or a t-butyl group.
It is also preferable that the hydrophobic resin further has a repeating unit represented by the following general formula (CII-AB).

In the formula (CII-AB),
R _c11 ′ and R _c12 ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
Zc ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).
The general formula (CII-AB) is more preferably the following general formula (CII-AB1) or general formula (CII-AB2).

Wherein (CII-AB1) and _{(CII-AB2), Rc 13} '~Rc 16' each independently represent a hydrogen atom, a halogen atom, an alkyl group or a cycloalkyl group.
It is also possible to form at least two members to the ring of Rc _l3 '~Rc _16'.
n represents 0 or 1.
Specific examples of the repeating unit represented by the general formula (VI) or (CII-AB) are shown below, but the present invention is not limited thereto. In the formula, Ra represents H, CH ₃ , CH ₂ OH, CF ₃ or CN.

  When the hydrophobic resin has fluorine atoms, the fluorine atom content is preferably 5 to 80% by mass, more preferably 6 to 50% by mass, and more preferably 7 to 40% by mass with respect to the molecular weight of the resin. % Is more preferable. Moreover, it is preferable that the repeating unit containing a fluorine atom is 10-100 mass% with respect to all the repeating units in resin, and it is more preferable that it is 20-100 mass%.

When resin has a silicon atom, it is preferable that the content rate of a silicon atom is 2-50 mass% with respect to the molecular weight of resin, and it is more preferable that it is 2-30 mass%. Moreover, it is preferable that the repeating unit containing a silicon atom is 10-90 mass% with respect to all the repeating units of resin, and it is more preferable that it is 20-80 mass%.
The weight average molecular weight of the resin in terms of standard polystyrene is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, and even more preferably 2,000 to 15,000.

  The resin content in the composition can be appropriately adjusted so that the receding contact angle of the composition film falls within the above range, but is 0.01 to 10% by mass based on the total solid content of the composition. More preferably, it is 0.1-9 mass%, More preferably, it is 0.5-8 mass%.

  As in the case of the acid-decomposable resin, it is natural that the resin has few impurities such as metals, and the residual monomer or oligomer component is preferably 0 to 10% by mass, more preferably 0 to 5% by mass. 0 to 1% by mass is even more preferable. Thereby, a composition having no change over time such as foreign matter in liquid or sensitivity can be obtained. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably in the range of 1 to 3, more preferably 1 to 2, and still more preferably 1 in terms of resolution, pattern shape, pattern sidewall, roughness, and the like. -1.8, most preferably in the range of 1-1.5.

  Various commercially available products can be used as the resin, and the resin can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the above-mentioned propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as the solvent used in the composition of the present invention. Thereby, the generation of particles during storage can be suppressed.

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

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

  The solvent (precipitation or reprecipitation solvent) used in the precipitation or reprecipitation operation from the polymer solution may be a poor solvent for the polymer, and may be a hydrocarbon, halogenated hydrocarbon, nitro, depending on the type of polymer. A compound, ether, ketone, ester, carbonate, alcohol, carboxylic acid, water, a mixed solvent containing these solvents, and the like can be appropriately selected for use. Among these, as a precipitation or reprecipitation solvent, a solvent containing at least an alcohol (particularly methanol or the like) or water is preferable.

  The amount of the precipitation or reprecipitation solvent used can be appropriately selected in consideration of efficiency, yield, and the like, but generally 100 to 10000 parts by mass, preferably 200 to 2000 parts by mass with respect to 100 parts by mass of the polymer solution, More preferably, it is 300-1000 mass parts.

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

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

The resin may be once deposited and separated, and then dissolved again in a solvent, and the resin may be brought into contact with a hardly soluble or insoluble solvent. That is, after completion of the radical polymerization reaction, a solvent in which the polymer is hardly soluble or insoluble is brought into contact, the resin is precipitated (step a), the resin is separated from the solution (step b), and dissolved again in the solvent. (Step c), and then contact the resin solution A with a solvent in which the resin is hardly soluble or insoluble in a volume amount less than 10 times that of the resin solution A (preferably 5 times or less volume). This may be a method including precipitating a resin solid (step d) and separating the precipitated resin (step e).
Specific examples of the resin will be shown. Table 2 below shows the molar ratio of repeating units in each resin (corresponding to each repeating unit in order from the left), weight average molecular weight (Mw), and dispersity (Mw / Mn).

The film formed from the composition according to the present invention is filled with a liquid (immersion medium) having a refractive index higher than that of air between the film and the lens when irradiated with actinic rays or radiation. You may go. Thereby, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred.
The immersion liquid used for the immersion exposure will be described below.

The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has the smallest possible temperature coefficient of refractive index so as to minimize distortion of the optical image projected onto the composition film. When the light source is an ArF excimer laser (wavelength; 193 nm), it is preferable to use water from the viewpoints of availability and ease of handling in addition to the above-described viewpoints.
Further, a medium having a refractive index of 1.5 or more can be used in that the refractive index can be further improved. This medium may be an aqueous solution or an organic solvent.

  When water is used as the immersion liquid, the surface tension of the water is reduced and the surface activity is increased, so that the composition film on the wafer is not dissolved and the influence on the optical coating on the lower surface of the lens element is ignored. A possible additive (liquid) may be added in a small proportion. The additive is preferably an aliphatic alcohol having a refractive index substantially equal to that of water, and specifically includes methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be made extremely small can be obtained. On the other hand, when an opaque substance or an impurity having a refractive index significantly different from that of water is mixed with 193 nm light, the optical image projected on the composition film is distorted. preferable. Further, pure water filtered through an ion exchange filter or the like may be used.

The electrical resistance of water is desirably 18.3 MQcm or more, the TOC (organic substance concentration) is desirably 20 ppb or less, and deaeration treatment is desirably performed.
Moreover, it is possible to improve lithography performance by increasing the refractive index of the immersion liquid. From such a viewpoint, an additive for increasing the refractive index may be added to water, or heavy water (D ₂ O) may be used instead of water.

  An immersion liquid poorly soluble film (hereinafter also referred to as “topcoat”) may be provided between the film of the composition of the present invention and the immersion liquid so that the film does not directly contact the immersion liquid. Good. The functions required for the top coat are suitability for application to the upper layer of the composition film, transparency to radiation, particularly 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the composition film and can be uniformly applied to the upper layer of the composition film.

  From the viewpoint of 193 nm transparency, the top coat is preferably a polymer that does not contain abundant aromatics. Specifically, the polymer contains a hydrocarbon polymer, an acrylate polymer, polymethacrylic acid, polyacrylic acid, polyvinyl ether, and silicon. Examples thereof include a polymer and a fluorine-containing polymer. The aforementioned hydrophobic resin is also suitable as a top coat. From the viewpoint of contaminating the optical lens when impurities are eluted from the top coat into the immersion liquid, it is preferable that the residual monomer component of the polymer contained in the top coat is small.

  When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having low penetration into the film is preferable. From the viewpoint that the peeling step can be performed at the same time as the film development processing step, it is preferable that the peeling step can be performed with a developer containing an organic solvent.

  The resolution is improved when there is no difference in refractive index between the top coat and the immersion liquid. In the case of using water as the immersion liquid in an ArF excimer laser (wavelength: 193 nm), the top coat for ArF immersion exposure is preferably close to the refractive index of the immersion liquid. From the viewpoint of making the refractive index close to the immersion liquid, it is preferable to have fluorine atoms in the topcoat. A thin film is more preferable from the viewpoint of transparency and refractive index.

  The top coat is preferably not mixed with the membrane and further not mixed with the immersion liquid. From this point of view, when the immersion liquid is water, the solvent used for the top coat is preferably a water-insoluble medium that is hardly soluble in the solvent used for the composition of the present invention. Furthermore, when the immersion liquid is an organic solvent, the topcoat may be water-soluble or water-insoluble.

(D) Basic compound The composition according to the present invention may further contain a basic compound. Preferred examples of the basic compound include compounds having structures represented by the following formulas (A) to (E).

In general formulas (A) and (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² each independently represent a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms), or an aryl group (having 6 to 6 carbon atoms). 20). R ²⁰¹ and R ²⁰² may be bonded to each other to form a ring.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ each independently represents an alkyl group having 1 to 20 carbon atoms.

  About the said alkyl group, as an alkyl group which has a substituent, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable. These alkyl groups are more preferably unsubstituted.

  Preferred basic compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine and piperidine. More preferable basic compounds include compounds having an imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, trialkylamine structure, aniline structure or pyridine structure, and alkylamine derivatives having a hydroxy group and / or an ether bond. And aniline derivatives having a hydroxy group and / or an ether bond.

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, and 2-phenylbenzimidazole.

  Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5, 4,0] Undecar 7-ene.

  Examples of the compound having an onium hydroxide structure include tetrabutylammonium hydroxide, triarylsulfonium hydroxide, phenacylsulfonium hydroxide, and sulfonium hydroxide having a 2-oxoalkyl group. More specifically, triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide and 2-oxopropylthiophenium hydroxy Do.

  Examples of the compound having an onium carboxylate structure include a compound having an onium hydroxide structure having a carboxylate as an anion. Examples of the carboxylate include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate.

  Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine.

  Examples of aniline compounds include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, and N, N-dihexylaniline.

Examples of the alkylamine derivative having a hydroxy group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, N-phenyldiethanolamine, and tris (methoxyethoxyethyl) amine.
Examples of the aniline derivative having a hydroxy group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

  Preferred examples of the basic compound further include an amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group.

In these compounds, it is preferable that at least one alkyl group is bonded to a nitrogen atom. Further, it is more preferable that an oxygen atom is contained in the chain of the alkyl group to form an oxyalkylene group. The number of oxyalkylene groups is preferably one or more in the molecule, more preferably 3 to 9, and still more preferably 4 to 6. Of these oxyalkylene _{groups, -CH 2 CH 2 O -,} - CH (CH 3) CH 2 O- or _-CH 2 _CH 2 _CH 2 O- by a group represented are especially preferred.

  Specific examples of these compounds include the compounds (C1-1) to (C3-3) exemplified in [0066] of US2007 / 0224539A.

  The composition according to the present invention comprises a low molecular compound having a nitrogen atom and a group capable of leaving by the action of an acid (hereinafter referred to as “low molecular compound (D)” or “compound (D)” as a basic compound. May also be included).

  The group leaving by the action of an acid is not particularly limited, but is preferably an acetal group, carbonate group, carbamate group, tertiary ester group, tertiary hydroxyl group, or hemiaminal ether group, and a carbamate group or hemiaminal ether group. Particularly preferred is a group.

  100-1000 are preferable, as for the molecular weight of a compound (D), 100-700 are more preferable, and 100-500 are especially preferable.

  As the compound (D), an amine derivative having a group capable of leaving by the action of an acid on the nitrogen atom is preferable.

Compound (D) may have a carbamate group having a protecting group on the nitrogen atom. The protecting group constituting the carbamate group can be represented by the following general formula (d-1), for example.

In general formula (d-1),
R ′ each independently represents a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkoxyalkyl group. R ′ may be bonded to each other to form a ring.

  R ′ is preferably a linear or branched alkyl group, a cycloalkyl group, or an aryl group. More preferably, it is a linear or branched alkyl group or a cycloalkyl group.

Specific examples of such groups are shown below.

  A compound (D) can also be comprised by combining arbitrarily the various basic compounds mentioned above and the structure represented by general formula (d-1).

  The compound (D) particularly preferably has a structure represented by the following general formula (F).

The compound (D) may correspond to the various basic compounds described above as long as it is a low molecular compound having a group capable of leaving by the action of an acid.

  In the general formula (F), Ra represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group. When n = 2, the two Ras may be the same or different, and the two Ras are bonded to each other to form a divalent heterocyclic hydrocarbon group (preferably having 20 or less carbon atoms) or a derivative thereof. May be formed.

  Rb independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkoxyalkyl group. However, in -C (Rb) (Rb) (Rb), when one or more Rb is a hydrogen atom, at least one of the remaining Rb is a cyclopropyl group, a 1-alkoxyalkyl group or an aryl group.

  At least two Rb may combine to form an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic hydrocarbon group or a derivative thereof.

  n represents an integer of 0 to 2, m represents an integer of 1 to 3, and n + m = 3.

  In the general formula (F), the alkyl group, cycloalkyl group, aryl group and aralkyl group represented by Ra and Rb are functional groups such as hydroxyl group, cyano group, amino group, pyrrolidino group, piperidino group, morpholino group and oxo group. , An alkoxy group and a halogen atom may be substituted. The same applies to the alkoxyalkyl group represented by Rb.

The alkyl group, cycloalkyl group, aryl group, and aralkyl group of Ra and / or Rb (these alkyl group, cycloalkyl group, aryl group, and aralkyl group are substituted with the above functional group, alkoxy group, or halogen atom). As may be)
For example, a group derived from a linear or branched alkane such as methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, etc., a group derived from these alkanes, for example, A group substituted with one or more cycloalkyl groups such as a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group,
Groups derived from cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, norbornane, adamantane, noradamantane, groups derived from these cycloalkanes, for example, methyl group, ethyl group, n-propyl group, a group substituted with one or more linear or branched alkyl groups such as i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like,
Groups derived from aromatic compounds such as benzene, naphthalene, anthracene, etc., and groups derived from these aromatic compounds are, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2 A group substituted with one or more linear or branched alkyl groups such as -methylpropyl group, 1-methylpropyl group, t-butyl group, and the like;
Groups derived from heterocyclic compounds such as pyrrolidine, piperidine, morpholine, tetrahydrofuran, tetrahydropyran, indole, indoline, quinoline, perhydroquinoline, indazole, benzimidazole, and groups derived from these heterocyclic compounds are linear or branched A group substituted with one or more groups derived from an alkyl group or aromatic compound, a group derived from a linear or branched alkane, a group derived from a cycloalkane, a phenyl group, a naphthyl group , A group substituted with one or more groups derived from an aromatic compound such as anthracenyl group or the like, or the above substituent is a hydroxyl group, cyano group, amino group, pyrrolidino group, piperidino group, morpholino group, oxo And a group substituted with a functional group such as a group.

  Examples of the divalent heterocyclic hydrocarbon group (preferably having 1 to 20 carbon atoms) or a derivative thereof formed by bonding of Ra to each other include, for example, pyrrolidine, piperidine, morpholine, 1, 4, 5 , 6-tetrahydropyrimidine, 1,2,3,4-tetrahydroquinoline, 1,2,3,6-tetrahydropyridine, homopiperazine, 4-azabenzimidazole, benzotriazole, 5-azabenzotriazole, 1H-1, 2,3-triazole, 1,4,7-triazacyclononane, tetrazole, 7-azaindole, indazole, benzimidazole, imidazo [1,2-a] pyridine, (1S, 4S)-(+)-2 , 5-diazabicyclo [2.2.1] heptane, 1,5,7-triazabicyclo [4.4.0] dec-5-ene Groups derived from heterocyclic compounds such as indole, indoline, 1,2,3,4-tetrahydroquinoxaline, perhydroquinoline, 1,5,9-triazacyclododecane, groups derived from these heterocyclic compounds A group derived from a linear or branched alkane, a group derived from a cycloalkane, a group derived from an aromatic compound, a group derived from a heterocyclic compound, a hydroxyl group, a cyano group, an amino group, a pyrrolidino group, a piperidino And groups substituted with one or more functional groups such as a group, a morpholino group and an oxo group.

A particularly preferred compound (D) in the present invention is specifically shown, but the present invention is not limited thereto.

The compound represented by the general formula (A) can be easily synthesized from a commercially available amine by a method described in Protective Groups in Organic Synthesis Fourth Edition. As the most general method, there is a method obtained by reacting a dicarbonate or haloformate with a commercially available amine. In the formula, X represents a halogen atom. The definition and specific examples of Ra and Rb are the same as those described in the general formula (F).

  One type of basic compound (including compound (D)) described above may be used alone, or two or more types may be used in combination.

  The total amount of the basic compound is preferably 0.001 to 20% by mass, more preferably 0.001 to 10% by mass, still more preferably 0.01 to 10% by mass, based on the total solid content of the composition. 5% by mass.

  The molar ratio of the total amount of the acid generator to the total amount of the basic compound is preferably 2.5 to 300, more preferably 5.0 to 200, and still more preferably 7.0 to 150. If this molar ratio is too small, sensitivity and / or resolution may be reduced. If this molar ratio is excessively large, pattern thickening may occur between exposure and heating (post-bake).

(E) Solvent The composition according to the present invention may contain a solvent.
Examples of the solvent include alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate ester, alkyl alkoxypropionate, cyclic lactone (preferably having 4 to 10 carbon atoms), and monoketone which may contain a ring. Examples thereof include organic solvents such as compounds (preferably having 4 to 10 carbon atoms), alkylene carbonate, alkyl alkoxyacetate, and alkyl pyruvate.

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

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

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

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

  Examples of cyclic lactones include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ-caprolactone, and γ-octano. And iclactone and α-hydroxy-γ-butyrolactone.

  Examples of the monoketone compound which may contain a ring include 2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone, 3-methyl-2-pentanone, 4-methyl-2-pentanone, and 2 -Methyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone, 3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone, 2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5-hexen-2-one 3-penten-2-one, cyclopentanone, 2-methylcyclopentanone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone, cyclohexanone, 3 -Methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone, 2-methylcycloheptanone and 3- And methylcycloheptanone.

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

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

  Examples of the alkyl pyruvate include methyl pyruvate, ethyl pyruvate, and propyl pyruvate.

  As the solvent, it is preferable to use a liquid having a normal boiling point (boiling point at 1 atm) of 130 ° C. or higher. Specifically, for example, cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, PGMEA, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethyl acetate, acetic acid-2 -(2-Ethoxyethoxy) ethyl and propylene carbonate are mentioned.

  Further, as the solvent, it is more preferable to use a liquid having a standard boiling point of 180 ° C. or higher, and it is more preferable to use a liquid having a standard boiling point of 200 ° C. or higher. When a liquid having a normal boiling point of 180 ° C. or higher is used as the solvent, it is possible to further reduce immersion defects. The reason for this is not necessarily clear, but the present inventors use this liquid because the solvent volatilization rate during spin coating changes and the material distribution in the wafer surface becomes uniform. It is estimated.

  The content of the liquid having a standard boiling point of 180 ° C. or higher is preferably 0.5 to 50% by mass, more preferably 1 to 30% by mass, and more preferably 1.5 to 10% with respect to the total amount of the solvent. More preferably, it is mass%.

  As the liquid having a normal boiling point of 180 ° C. or higher, those having one or more oxygen atoms are preferable, those having two or more oxygen atoms are more preferable, and those having a ring structure are particularly preferable. Examples of such liquids include lactones and cyclic carbonates. More specifically, examples include γ-butyrolactone (standard boiling point: 204 ° C.) and propylene carbonate (standard boiling point: 242 ° C.).

  These solvents may be used alone or in combination of two or more. In the latter case, it is preferable to use a mixed solvent of a solvent containing a hydroxy group and a solvent not containing a hydroxy group.

  Examples of the solvent containing a hydroxy group include alkylene glycol monoalkyl ether and alkyl lactate. Of these, propylene glycol monomethyl ether or ethyl lactate is more preferable.

  As the solvent not containing a hydroxy group, for example, alkylene glycol monoalkyl ether acetate, alkyl alkoxypropionate, a monoketone compound which may contain a ring, cyclic lactone and alkyl acetate are preferable. Of these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone or butyl acetate are more preferred, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate or 2-heptanone is particularly preferred. .

  When a mixed solvent of a solvent containing a hydroxy group and a solvent not containing a hydroxy group is used, the mass ratio thereof is preferably 1/99 to 99/1, more preferably 10/90 to 90/10. And more preferably 20/80 to 60/40.

  When a mixed solvent containing 50% by mass or more of a solvent not containing a hydroxy group is used, particularly excellent coating uniformity can be achieved. The solvent is particularly preferably a mixed solvent of PGMEA and one or more other solvents.

  The solvent is preferably a mixed solvent of propylene glycol monomethyl ether acetate and at least one other solvent.

(F) Surfactant The composition according to the present invention may further contain a surfactant. By containing a surfactant, when an exposure light source having a wavelength of 250 nm or less, particularly 220 nm or less, is used, it is possible to form a pattern with less adhesion and development defects with good sensitivity and resolution. Become.

As the surfactant, it is particularly preferable to use a fluorine-based and / or silicon-based surfactant.
Examples of the fluorine-based and / or silicon-based surfactant include surfactants described in [0276] of US Patent Application Publication No. 2008/0248425. Also, F-top EF301 or EF303 (manufactured by Shin-Akita Kasei Co., Ltd.); Florard FC430, 431 or 4430 (manufactured by Sumitomo 3M Co., Ltd.); Megafac F171, F173, F176, F189, F113, F110, F177, F120 or R08 (Dainippon Ink Chemical Co., Ltd.); Surflon S-382, SC101, 102, 103, 104, 105 or 106 (Asahi Glass Co., Ltd.); Troisol S-366 (Troy Chemical Co., Ltd.); GF-300 or GF-150 (manufactured by Toa Gosei Chemical Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.); F-top EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, EF352, EF801, EF802 or F601 (manufactured by Gemco); PF636, PF656, PF6320 or PF6520 (manufactured by OMNOVA); or FTX-204G, 208G, 218G, 230G, 204D, 208D, 212D, 218D or 222D (manufactured by Neos) May be used. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

  In addition to the known surfactants described above, the surfactant is a fluoroaliphatic compound produced by a telomerization method (also referred to as a telomer method) or an oligomerization method (also referred to as an oligomer method). You may synthesize. Specifically, a polymer having a fluoroaliphatic group derived from this fluoroaliphatic compound may be used as a surfactant. This fluoroaliphatic compound can be synthesized, for example, by the method described in JP-A-2002-90991.

  The polymer having a fluoroaliphatic group is preferably a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate or methacrylate and / or (poly (oxyalkylene)) methacrylate. Even if it distributes, block copolymerization may be sufficient.

  Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, and a poly (oxybutylene) group. In addition, units having different chain length alkylene in the same chain, such as poly (block connection body of oxyethylene, oxypropylene, and oxyethylene) and poly (block connection body of oxyethylene and oxypropylene) Also good.

  Further, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate or methacrylate has a monomer having two or more different fluoroaliphatic groups and two or more different (poly (oxyalkylene). )) It may be a ternary or higher copolymer obtained by copolymerizing acrylate or methacrylate simultaneously.

For example, Megafac F178, F-470, F-473, F-475, F-476 and F-472 (Dainippon Ink Chemical Co., Ltd.) are mentioned as commercially available surfactants. Further, a copolymer of an acrylate or methacrylate having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate or methacrylate, an acrylate or methacrylate having a C ₆ F ₁₃ group and (poly (oxyethylene)) acrylate or methacrylate And a copolymer of (poly (oxypropylene)) acrylate or methacrylate, a copolymer of an acrylate or methacrylate having a C ₈ F ₁₇ group and (poly (oxyalkylene)) acrylate or methacrylate, and C ₈ F ₁₇ And a copolymer of an acrylate or methacrylate having a group and (poly (oxyethylene)) acrylate or methacrylate and (poly (oxypropylene)) acrylate or methacrylate. That.

  Further, surfactants other than fluorine-based and / or silicon-based surfactants described in [0280] of US Patent Application Publication No. 2008/0248425 may be used.

One of these surfactants may be used alone, or two or more thereof may be used in combination.
When the composition according to the present invention contains a surfactant, the content is preferably 0 to 2% by mass, more preferably 0.0001 to 2% by mass, based on the total solid content of the composition. More preferably, it is 0.0005-1 mass%.

(G) Other additives The composition according to the present invention comprises a compound that promotes solubility in a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and / or a developer (for example, a molecular weight of 1000 The following phenol compounds or alicyclic or aliphatic compounds containing a carboxy group) may further be included.

  The composition according to the present invention may further contain a dissolution inhibiting compound. Here, the “dissolution inhibiting compound” is a compound having a molecular weight of 3000 or less, which is decomposed by the action of an acid to reduce the solubility in a developer containing an organic solvent.

  As this dissolution inhibiting compound, since it does not decrease the transmittance for light having a wavelength of 220 nm or less, acid decomposition such as a cholic acid derivative containing an acid-decomposable group described in Proceeding of SPIE, 2724, 355 (1996) An alicyclic or aliphatic compound containing a functional group is preferred. Examples of the acid-decomposable group and the alicyclic structure include the same ones as described above.

  In addition, when the composition according to the present invention was exposed to KrF excimer laser or irradiated with an electron beam, the dissolution inhibiting compound included a structure in which the phenolic hydroxy group of the phenol compound was substituted with an acid-decomposable group. Compounds are preferred. As a phenol compound, what contains 1-9 phenol frame | skeleton is preferable, and what contains 2-6 pieces is still more preferable.

  When the composition according to the present invention contains a dissolution inhibiting compound, the content thereof is preferably 3 to 50% by mass, more preferably 5 to 40% by mass, based on the total solid content of the composition. is there.

Specific examples of the dissolution inhibiting compound are given below.

  For example, phenol compounds having a molecular weight of 1000 or less can be easily obtained with reference to the methods described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, and the like. Can be synthesized.

  Examples of alicyclic or aliphatic compounds containing a carboxy group include carboxylic acid derivatives containing steroid structures such as cholic acid, deoxycholic acid and lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, And cyclohexanedicarboxylic acid.

<Pattern formation method>
The pattern forming method according to the present invention includes (A) forming a film using the composition described above, (B) exposing the film, and (C) a developer containing an organic solvent. And developing the exposed film. This method may further include (D) rinsing the developed film with a rinsing solution.

  It is also preferable to include a preheating (PB) step after the film formation and before the exposure step. It is also preferable to include a post exposure bake (PEB) step after the exposure step and before the development step.

The heating temperature is preferably 40 to 130 ° C., more preferably 50 to 120 ° C., and still more preferably 60 to 110 ° C. for both the PB process and the PEB process. In particular, when the PEB process is performed at a low temperature of 60 to 90 ° C., the exposure latitude (EL) and the resolution can be remarkably improved.
The heating time is preferably 30 to 300 seconds, more preferably 30 to 180 seconds, and still more preferably 30 to 90 seconds.

  In the pattern forming method according to the present invention, the step of forming a film of the composition on the substrate, the step of exposing the film, the heating step, and the developing step can be performed by generally known methods.

There is no limitation on the wavelength of the light source used for exposure of the, for example, KrF excimer laser wavelength (248 nm), ArF excimer laser wavelength (193 nm), and, _{F 2} excimer laser wavelength (157 nm) and the like.

Liquid immersion exposure may be performed on the film formed using the composition according to the present invention. Thereby, the resolution can be further improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred.
In this case, the above-described hydrophobic resin may be added to the composition in advance, or after forming a film, an immersion liquid hardly soluble film (hereinafter also referred to as “topcoat”) may be provided thereon. Good. The performance required for the top coat and how to use it are described in Chapter 7 of CM Publishing “Immersion Lithography Processes and Materials”.

  From the viewpoint of transparency to a laser having a wavelength of 193 nm, the top coat is preferably a polymer that does not contain abundant aromatics. For example, hydrocarbon polymer, acrylate polymer, polymethacrylic acid, polyacrylic acid, polyvinyl ether, silicon And a fluorine-containing polymer. The hydrophobic resin described above is also suitable as a top coat. Commercially available top coat materials can also be used as appropriate.

  When the topcoat is peeled after exposure, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having low penetration into the film is preferable. From the viewpoint that the peeling step can be performed simultaneously with the development processing step of the film, it is preferable that the peeling step can be performed with a developer.

In the present invention, the substrate on which the film is formed is not particularly limited. As the substrate, a substrate generally used in a semiconductor manufacturing process such as an IC, a manufacturing process of a circuit board such as a liquid crystal and a thermal head, and other photofabrication lithography processes can be used. Examples of such a substrate, e.g., silicon, SiN, and SiO ₂ or the like of the inorganic substrate, as well, include coating inorganic substrates such as SOG. Further, if necessary, an organic antireflection film may be formed between the film and the substrate.

  Examples of the developer containing an organic solvent include polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents, and developers containing hydrocarbon solvents. .

  Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, and methyl ethyl ketone. , Methyl isobutyl ketone, acetyl acetone, acetonyl acetone, ionone, diacetyl alcohol, acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, and propylene carbonate.

  Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3- Ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, methyl propionate, ethyl propionate And propyl propionate. In particular, alkyl acetates such as methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate and amyl acetate or propionate alkyl esters such as methyl propionate, ethyl propionate and propyl propionate are preferred.

  Examples of the alcohol solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, 4-methyl-2- Alcohols such as pentanol, n-heptyl alcohol, n-octyl alcohol and n-decanol; glycols such as ethylene glycol, diethylene glycol and triethylene glycol; and ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, Propylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl Glycol ethers such as ether and methoxymethyl butanol.

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

  Examples of amide solvents include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, and 1,3-dimethyl-2-imidazolidinone. Can be mentioned.

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

  Two or more of the above solvents may be mixed and used. Moreover, you may mix and use with solvent and / or water other than the above within the range which can exhibit sufficient performance. However, the water content of the entire developer is preferably less than 10% by mass, and more preferably the developer does not substantially contain moisture. That is, this developer is preferably a developer substantially consisting of only an organic solvent. Even in this case, the developer may contain a surfactant described later. In this case, the developer may contain unavoidable impurities derived from the atmosphere.

  The amount of the organic solvent used in the developer is preferably 80% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and 95% by mass with respect to the total amount of the developer. More preferably, it is 100 mass% or less.

  In particular, the organic solvent contained in the developer is preferably at least one selected from ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

  The vapor pressure of the developer containing the organic solvent is preferably 5 kPa or less, more preferably 3 kPa or less, and particularly preferably 2 kPa or less at 20 ° C. By setting the vapor pressure of the developing solution to 5 kPa or less, evaporation of the developing solution on the substrate or in the developing cup is suppressed, and temperature uniformity in the wafer surface is improved. As a result, dimensional uniformity in the wafer surface. Will improve.

  Specific examples of the developer having a vapor pressure of 5 kPa or less include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone and Ketone solvents such as methyl isobutyl ketone; butyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3- Such as methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, butyl formate, propyl formate, ethyl lactate, butyl lactate and propyl lactate Ter solvent: n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, 4-methyl-2-pentanol, n-heptyl alcohol, n- Alcohol solvents such as octyl alcohol and n-decanol; glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol; ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol Glycos such as monomethyl ether, triethylene glycol monoethyl ether and methoxymethylbutanol Ether solvents; ether solvents such as tetrahydrofuran; amide solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide and N, N-dimethylformamide; aromatic hydrocarbon solvents such as toluene and xylene; In addition, aliphatic hydrocarbon solvents such as octane and decane are listed.

  Specific examples of the developer having a vapor pressure of 2 kPa or less include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, and phenylacetone. Ketone solvents of: butyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, Ester solvents such as 3-methyl-3-methoxybutyl acetate, ethyl lactate, butyl lactate and propyl lactate; n-butyl alcohol, sec-butyl Alcohol solvents such as alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, 4-methyl-2-pentanol, n-heptyl alcohol, n-octyl alcohol and n-decanol; ethylene glycol, diethylene glycol and triethylene glycol Glycol solvents such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether and methoxymethyl butanol; N -Methyl-2-pyrrolidone, N, N-dimethylacetamide and N, N-dimethylform Bromide amide solvents; aromatic hydrocarbon solvents such as xylene; and include aliphatic hydrocarbon solvents such as octane and decane.

An appropriate amount of a surfactant can be added to the developer as necessary.
Although there is no restriction | limiting in particular in this surfactant, For example, an ionic or nonionic fluorine type and / or silicon type surfactant can be used. Examples of these fluorine and / or silicon surfactants are, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950. JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, US Pat. No. 5,405,720, Mention may be made of the surfactants described in the specifications of US Pat. it can. This surfactant is preferably nonionic. As the nonionic surfactant, it is more preferable to use a fluorine-based surfactant or a silicon-based surfactant.

  In addition, the usage-amount of surfactant is 0.001-5 mass% normally with respect to the whole quantity of a developing solution, Preferably it is 0.005-2 mass%, More preferably, it is 0.01-0. 0.5% by mass.

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

When the above various development methods include a step of discharging the developer from the developing nozzle of the developing device toward the composition film, the discharge pressure of the discharged developer (flow rate per unit area of the discharged developer) Is preferably 2 mL / sec / mm ² or less, more preferably 1.5 mL / sec / mm ² or less, and even more preferably 1 mL / sec / mm ² or less. There is no particular lower limit on the flow rate, but considering the throughput, it is preferably 0.2 mL / sec / mm ² or more.
By setting the discharge pressure of the discharged developer within the above range, pattern defects derived from the composition residue after development can be remarkably reduced.

The details of this mechanism are not clear, but perhaps by setting the discharge pressure within the above range, the pressure applied to the composition film by the developer is reduced, and the composition film and / or pattern is inadvertently cut or collapsed. This is considered to be suppressed.
The developer discharge pressure (mL / sec / mm ² ) is a value at the developing nozzle outlet in the developing device.

Examples of a method for adjusting the discharge pressure of the developer include a method of adjusting the discharge pressure with a pump and the like, and a method of changing the pressure by adjusting the pressure by supply from a pressurized tank.
Moreover, you may implement the process of stopping image development, after the process of developing, substituting with another solvent.

  The pattern forming method according to the present invention preferably includes a rinsing step (a step of cleaning the film using a rinsing liquid containing an organic solvent) after the developing step.

  The rinsing liquid used in the rinsing step is not particularly limited as long as it does not dissolve the pattern after development, and a solution containing a general organic solvent can be used.

  Examples of the rinsing liquid include those containing at least one organic solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. More preferably, the rinse liquid contains at least one organic solvent selected from a ketone solvent, an ester solvent, an alcohol solvent, and an amide solvent, and more preferably an alcohol solvent or an ester. It contains a system solvent.

The rinsing liquid preferably contains a monohydric alcohol, and more preferably contains a monohydric alcohol having 5 or more carbon atoms.
These monohydric alcohols may be linear, branched, or cyclic. Examples of these monohydric alcohols include 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, and 4-methyl-2- Examples include pentanol, 1-heptanol, 1-octanol, 2-hexanol, cyclopentanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, and 4-octanol. Examples of the monohydric alcohol having 5 or more carbon atoms include 1-hexanol, 2-hexanol, 4-methyl-2-pentanol, 1-pentanol, and 3-methyl-1-butanol.

  Each of the above components may be used as a mixture of two or more, or may be used as a mixture with an organic solvent other than the above.

  The water content of the rinsing liquid is preferably less than 10% by mass, preferably less than 5% by mass, and more preferably less than 3% by mass. That is, the amount of the organic solvent used in the rinse liquid is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, based on the total amount of the rinse liquid. It is particularly preferable that the content is not less than 100% by mass. By setting the water content of the rinse liquid to less than 10% by mass, even better development characteristics can be achieved.

The vapor pressure of the rinse liquid is preferably 0.05 kPa to 5 kPa at 20 ° C., more preferably 0.1 kPa to 5 kPa, and more preferably 0.12 kPa to 3 kPa. Is more preferable. By setting the vapor pressure of the rinsing liquid to 0.05 kPa or more and 5 kPa or less, temperature uniformity in the wafer surface is improved, and swelling due to penetration of the rinsing liquid is suppressed, and dimensional uniformity in the wafer surface is achieved. It improves.
An appropriate amount of a surfactant may be added to the rinse solution.

  In the rinsing step, the developed wafer is cleaned using the above rinsing liquid. The method of the cleaning process is not particularly limited. For example, a method of continuing to discharge the rinse liquid onto the substrate rotating at a constant speed (rotary coating method), and immersing the substrate in a bath filled with the rinse liquid for a certain period of time. Examples thereof include a method (dip method) and a method (spray method) in which a rinse liquid is sprayed onto the substrate surface. Among these, it is preferable to remove the rinse liquid from the substrate by performing a cleaning process by a spin coating method and then rotating the substrate at a rotational speed of 2000 rpm to 4000 rpm.

  The pattern formation method according to the present invention may include a development step (positive pattern formation step) using an alkaline developer in addition to a development step using a developer containing an organic solvent. There is no particular limitation on the order of the development step using an alkali developer and the development step using a developer containing an organic solvent, but development using an alkali developer was performed using a developer containing an organic solvent. More preferably, it is performed before development. Moreover, it is preferable to accompany a heating process before each image development process.

  The type of alkali developer is not particularly limited, but an aqueous solution of tetramethylammonium hydroxide is usually used. An appropriate amount of alcohol and / or surfactant may be added to the alkaline developer.

  The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass. The pH of the alkali developer is usually from 10.0 to 15.0. As the alkali developer, it is particularly preferable to use a 2.38% by mass aqueous solution of tetramethylammonium hydroxide.

  When rinsing is performed after development using an alkaline developer, pure water is typically used as the rinse. An appropriate amount of a surfactant may be added to the rinse solution.

<Acid-decomposable resin>
The following resins (P-1) to (P-12) were synthesized as shown below. Moreover, the following resin (CP-1) was prepared.

In Table 3 below, the weight average molecular weight Mw, the dispersity Mw / Mn, and the composition ratio of each repeating unit (corresponding in order from the left) in the resins (P-1) to (P-12) and (CP-1) are shown. Put together.

[Synthesis Example 1: Resin (P-1)]
Under a nitrogen stream, 200 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. In this way, solvent 1 was obtained. Next, the following monomer-1 (29.7 g) and monomer-2 (71.4 g) were dissolved in cyclohexanone (372 g) to prepare a monomer solution. Furthermore, 6.6 mol% of polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the total amount of monomers, and the dissolved solution was added dropwise to the solvent 1 over 6 hours. After completion of dropping, the reaction was further continued at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then added dropwise to a mixed solvent of heptane 7736 g / ethyl acetate 859 g, and the precipitated powder was collected by filtration and dried to obtain 73 g of resin (A-1). The weight average molecular weight of the obtained resin (P-1) was 10,500, the dispersity (Mw / Mn) was 1.88, and the composition ratio measured by ¹³ C-NMR was 40/60.

[Synthesis Example 2: Resins (P-2) to (P-12)]
Resins (P-2) to (P-12) were synthesized in the same manner as described in Synthesis Example 1. The weight average molecular weight, dispersity (Mw / Mn), and composition ratio of these resins were as shown in Table 3 above.

<Hydrophobic resin>
The following resins (1b) to (12b) were synthesized as shown below.

Table 4 below summarizes the weight average molecular weight Mw, the degree of dispersion Mw / Mn, and the composition ratio of each repeating unit (corresponding in order from the left) in the resins (1b) to (12b).

[Synthesis Example 3: Resin (1b)]
Monomers corresponding to each repeating unit of the hydrophobic resin (1b) were charged at a ratio (molar ratio) of 60/40, dissolved in propylene glycol monomethyl ether acetate (PGMEA), and 450 g of a solution having a solid content concentration of 15% by mass was dissolved. Prepared. 10.0 mol% of Wako Pure Chemical Co., Ltd. polymerization initiator V-601 was added to this solution, and this was added dropwise to 50 g of PGMEA heated to 85 ° C. in a nitrogen atmosphere over 6 hours. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution is cooled to room temperature, dropped into a mixed solution of 5 L of methanol and 100 ml of water over 20 minutes while stirring, and the precipitated white powder is collected by filtration to recover the target resin (1b). did.

  The polymer composition ratio determined from NMR was 60/40. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 4500, and dispersion degree was 1.50.

[Synthesis Example 4: Resins (2b) to (12b)]
Resins (2b) to (12b) were synthesized in the same manner as described in Synthesis Example 3. The weight average molecular weight, dispersity (Mw / Mn) and composition ratio of these resins were as shown in Table 4 above.

<Acid generator>
The following compounds (PAG-1) to (PAG-12) were prepared as acid generators.

<Basic compound>
The following were used as basic compounds.

<Additives>
The following compounds (AD-1) to (AD-5) were prepared as additives.

<Surfactant>
The following were prepared as surfactants.
W-1: MegaFuck F176 (Dainippon Ink & Chemicals, Inc .; fluorine-based)
W-2: Megafuck R08 (Dainippon Ink & Chemicals, Inc .; fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd .; silicon-based)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-5: KH-20 (Asahi Kasei Corporation)
W-6: PolyFox PF-6320 (manufactured by OMNOVA solution inc .; fluorine-based).

<Solvent>
The following were prepared as solvents.
(Group a)
SL-1: Propylene glycol monomethyl ether acetate SL-2: Propylene glycol monomethyl ether propionate SL-3: 2-heptanone.

(Group b)
SL-4: Ethyl lactate SL-5: Propylene glycol monomethyl ether SL-6: Cyclohexanone.

(Group c)
SL-7: γ-butyrolactone SL-8: Propylene carbonate.

<Preparation of resist composition>
The components shown in Table 5 below were dissolved in the solvents shown in the same table, and each was filtered through a polyethylene filter having a pore size of 0.03 μm to prepare a resist composition. An organic antireflection film ARC29SR (manufactured by Nissan Chemical Industries, Ltd.) was applied on the silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 86 nm. A resist composition was applied thereon and baked (PB) at 100 ° C. for 60 seconds to form a resist film having a thickness of 100 nm.

An exposure mask (line) is used on the obtained wafer using an ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA 1.20, C-Quad, outer sigma 0.981, inner sigma 0.895, XY deflection). / Space = 1/1), pattern exposure was performed. At this time, ultrapure water was used as the immersion liquid. Then, it heated at 85 degreeC for 60 second (PEB). Next, the developer (butyl acetate) was paddled for 30 seconds for development, and then rinsed with a rinse solution (4-methyl-2-pentanol) for 30 seconds. Subsequently, the wafer was rotated at 4000 rpm for 30 seconds and then baked at 90 ° C. for 60 seconds. In this way, a 75 nm (1: 1) line and space resist pattern was obtained.

<Evaluation method>
[Limit resolution (space width)]
When the exposure amount that reproduces a mask pattern of 75 nm (1: 1) line and space is the optimum exposure amount, and the exposure amount is further increased from the optimum exposure amount, the line width is reduced. The width of the space (nm) that is resolved without bridging by a bridge or developing residue is defined as “limit resolution”. A smaller value indicates that a finer pattern is resolved, indicating that the resolution is superior.

[Development defects]
The exposure amount and focus for forming a 75 nm (1: 1) line-and-space resist pattern are the optimum exposure amount and the optimum focus, respectively. Residual defects of the pattern obtained under the conditions of the optimum exposure amount and the optimum focus are Using a defect inspection apparatus (KLA-Tencor 2360), each 8 inch wafer was digitized. Residual defects were evaluated according to the following criteria.

◎ (Excellent): 0-50 pieces;
○ (Good): 51-100 pieces;
△ (Fair): 101-150 pieces;
× (Insufficient): 151 or more.

(Immersion defect)
About the obtained sample wafer, the development defect site | part was detected with KLA2360 machine (made by KLA Tencor Co., Ltd.). The detected development defect site was observed using a length measurement SEM (Hitachi S9380), and the number of immersion defects was determined. Here, the immersion defect is a defect (bubble defect) due to bubble biting during immersion exposure as illustrated in FIG. 1 or a defect (water remaining defect) caused by remaining immersion liquid on the wafer surface. These are generic names, and the total number of these is called the number of immersion defects. In this case, the number of immersion defects is 0 (Excellent) when the number of immersion defects is 0 / cm ² , ○ (Good) when the number is more than 0 / cm ^{2 and not} more than 0.01 / cm ² , 0.01 / greater than cm ² 0.1 / cm ² or less of those of △ (Fair), it was × (Insufficient) those more than 0.1 pieces / cm ^2.

[Pattern shape]
The cross-sectional pattern was observed using a length measuring SEM (Hitachi S9380). The rectangular pattern was ○ (Good), and the T-top shape was partially observed △ (Fair). The result was taken as x (Insufficient).
These evaluation results are shown in Table 6 below.

  As can be seen from Table 6, the compositions according to the examples were superior in development defect performance, immersion defect performance, and limit resolving power as compared with the compositions according to the comparative examples. Moreover, when the composition which concerns on an Example was used, it turned out that the pattern with a more favorable shape can be formed compared with the case where the composition which concerns on a comparative example is used.

Moreover, the following points became clear from the results shown in Table 6.
(1) From comparison between Reference Examples 5 and 6 and other examples, it was found that particularly excellent development defect performance can be achieved by using a hydrophobic resin containing a repeating unit having a carboxy group.

  (2) According to a comparison between Examples 2, 3, Reference Examples 4, 6, Examples 9, 10 and Reference Example 13 and other examples, it does not contain a repeating unit having an acid-decomposable group, or It was found that particularly excellent limiting resolution can be achieved when a hydrophobic resin having a content of 20 mol% or less with respect to all repeating units is used.

  (3) Comparison between Example 2 and Reference Examples 4, 5 and 8 and other examples shows that when a solvent containing a liquid having a standard boiling point of 180 ° C. or higher is used, particularly excellent immersion defect performance can be achieved. I understood.

Claims (13)

(A) does not contain a fluorine atom and / or an aromatic group, and a tree fat solubility in a developer containing an organic solvent is reduced by the action of an acid,
(B) a compound that generates an acid upon irradiation with an actinic ray or radiation;
(C) an actinic ray-sensitive or radiation-sensitive resin composition containing a hydrophobic resin,
The resin (a) is a resin containing only a repeating unit (P) having a group that decomposes by the action of an acid to generate an alcoholic hydroxy group as a repeating unit having an acid-decomposable group,
The compound (b), at least, an active ray or radiation actinic ray-sensitive or radiation-sensitive resin composition is a compound which generates an acid containing no fluorine atom upon irradiation with.   (A) a resin which does not contain a fluorine atom and / or an aromatic group and whose solubility in a developer containing an organic solvent is reduced by the action of an acid;
  (B) a compound that generates an acid upon irradiation with an actinic ray or radiation;
  (C) a hydrophobic resin and
An actinic ray-sensitive or radiation-sensitive resin composition containing
  The resin (a) is a repeating unit having an acid-decomposable group, and has at least one repeating unit (P) having a group capable of decomposing by the action of an acid to generate an alcoholic hydroxy group. A resin containing only one type of repeating unit (B) having a group that generates a carboxy group,
  The actinic ray-sensitive or radiation-sensitive resin composition, wherein the compound (b) is a compound that generates an acid containing no fluorine atom when irradiated with actinic rays or radiation. The composition according to claim 1 or 2 , wherein the hydrophobic resin (c) contains at least one of a fluorine atom and a silicon atom. The hydrophobic resin (c) does not contain a repeating unit having a group decomposing by the action of an acid, or contains the repeating unit having a group decomposing by the action of an acid, and the content thereof is all The composition according to any one of claims 1 to 3, which is 20 mol% or less based on the repeating unit. The composition according to any one of claims 1 to 4 , further comprising a solvent, wherein the solvent includes a liquid having a normal boiling point of 180 ° C or higher. The composition according to any one of claims 1 to 5 , wherein the repeating unit (P) is represented by at least one selected from the group consisting of the following general formulas (I-1) to (I-10). object.
Where
Each Ra independently represents a hydrogen atom, an alkyl group, or a group represented by —CH ₂ —O—Ra ₂ . Here, Ra2 represents a hydrogen atom, an alkyl group, or an acyl group.
R ₁ represents an (n + 1) valent organic group.
R ₂ independently represents a single bond or an (n + 1) -valent organic group when m ≧ 2.
OP each independently represents the above group which decomposes by the action of an acid to produce an alcoholic hydroxy group. When n ≧ 2 and / or m ≧ 2, two or more OPs may be bonded to each other to form a ring.
W represents a methylene group, an oxygen atom or a sulfur atom.
n and m represent an integer of 1 or more.
l represents an integer of 0 or more.
L ₁ represents a linking group represented by —COO—, —OCO—, —CONH—, —O—, —Ar—, —SO ₃ — or —SO ₂ NH—. Here, Ar represents a divalent aromatic ring group.
Each R independently represents a hydrogen atom or an alkyl group.
R ₀ represents a hydrogen atom or an organic group.
L ₃ represents a (m + 2) -valent linking group.
R ^L each independently represents an (n + 1) -valent linking group when m ≧ 2.
R ^S each independently represents a substituent when p ≧ 2. For p ≧ 2, plural structured R ^S may be bonded to each other to form a ring.
p represents an integer of 0 to 3. The groups decompose to produce an alcoholic hydroxyl group by the action of an acid, according to claim 1 to 6 are represented by at least one selected from the group consisting of the following general formula (II-1) to (II-9) The composition according to any one of the above.
Where
R ₃ each independently represents a hydrogen atom or a monovalent organic group. Two R _{3 s} may be bonded to each other to form a ring.
R ₄ each independently represents a monovalent organic group. At least two R ₄ may be bonded to each other to form a ring. R ₃ and R ₄ may be bonded to each other to form a ring.
R ₅ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, or an alkynyl group. At least two R ₅ may be bonded to each other to form a ring. However, when one or two of the three R ₅ are hydrogen atoms, at least one of the remaining R ₅ represents an aryl group, an alkenyl group, or an alkynyl group.
R ₆ each independently represents a hydrogen atom or a monovalent organic group. R ₆ may be bonded to each other to form a ring. The composition according to any one of claims 1 to 7 , wherein the repeating unit (P) is represented by the following general formula (III).
Where
R ₁ represents an (n + 1) valent organic group.
Ra represents a hydrogen atom, an alkyl group, or a group represented by —CH ₂ —O—Ra ₂ . Here, Ra2 represents a hydrogen atom, an alkyl group, or an acyl group.
R ₃ each independently represents a hydrogen atom or a monovalent organic group. R ₃ may be bonded to each other to form a ring.
R ₄ each independently represents a monovalent organic group when n ≧ 2. R ₄ may be bonded to each other to form a ring. R ₃ and R ₄ may be bonded to each other to form a ring.
n represents an integer of 1 or more. The low molecular compound (D) having a group represented by the following general formula (d-1) on a nitrogen atom and further having a nitrogen atom and a group capable of leaving by the action of an acid. The composition according to any one of the above.
  Where
  R ′ each independently represents a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkoxyalkyl group. R ′ may be bonded to each other to form a ring. Resist pattern formed by using a composition according to any one of claims 1 to 9. (A) forming a film using the composition according to any one of claims 1 to 9 ,
(B) exposing the film;
(C) A pattern forming method including developing the exposed film. The method of claim 11 , wherein the exposure is performed via an immersion liquid. The method according to claim 11 or 12 , wherein the development is performed using a developer containing an organic solvent.