JP5039345B2 - Positive resist composition and pattern forming method using the same - Google Patents

Description

  The present invention relates to a positive resist composition suitably used in an ultramicrolithography process such as the manufacture of VLSI and high-capacity microchips and other photo-publishing processes, and a pattern forming method using the same. More specifically, the present invention relates to a positive resist composition capable of forming a highly refined pattern using an electron beam, X-ray, EUV light (Extreme Ultraviolet: wavelength of around 13 nm), and a pattern forming method using the same. In addition, the present invention relates to a positive resist composition that can be suitably used for microfabrication of a semiconductor device using electron beam, X-ray, EUV light, and the like, and a pattern forming method using the same.

  Conventionally, in the manufacturing process of semiconductor devices such as IC and LSI, fine processing by lithography using a resist composition has been performed. In recent years, with the high integration of integrated circuits, the formation of ultrafine patterns in the submicron region and the quarter micron region has been required. Along with this, there is a tendency for the exposure wavelength to be shortened from g-line to i-line, and further to KrF excimer laser light. Furthermore, at present, in addition to excimer laser light, lithography using electron beams, X-rays, or EUV light is also being developed.

  Lithography using an electron beam or EUV light is positioned as a next-generation or next-generation pattern forming technology, and a positive resist with high sensitivity and high resolution is desired. In particular, high sensitivity is a very important issue for shortening the wafer processing time. However, in positive resists for electron beams and EUV, if high sensitivity is to be pursued, not only the resolution will be lowered. As a result, the line edge roughness deteriorates, and it is strongly desired to develop a resist that satisfies these characteristics simultaneously. Here, the line edge roughness means that when the pattern is viewed from directly above because the resist pattern and the edge of the substrate interface vary irregularly in the direction perpendicular to the line direction due to the characteristics of the resist. Say that the edge looks uneven. The unevenness is transferred by an etching process using a resist as a mask, and the electrical characteristics are deteriorated, so that the yield is lowered. Particularly in the ultrafine region of 0.25 μm or less, the line edge roughness is an extremely important improvement issue. High sensitivity, high resolution, good pattern shape, and good line edge roughness are in a trade-off relationship, and it is very important how to satisfy them simultaneously.

  Similarly, in lithography using X-rays or EUV light, it is important to achieve high sensitivity, and it is necessary to solve these problems.

  As a resist suitable for a lithography process using such an electron beam, X-ray or EUV light, a chemically amplified resist using an acid catalyst reaction is mainly used from the viewpoint of high sensitivity. Is a polymer having a property of being insoluble or hardly soluble in an alkaline aqueous solution and soluble in an alkaline aqueous solution by the action of an acid (hereinafter sometimes abbreviated as an acid-decomposable resin), and an acid generator. The chemically amplified composition is effectively used.

  Regarding a positive resist for electron beam or X-ray, for example, Patent Document 1 (Japanese Patent Laid-Open No. 4-219757) discloses that 20 to 70% of the phenolic hydroxy group of poly (p-hydroxystyrene) is an acetal group. Resist compositions containing substituted polymers are disclosed.

Patent Document 2 (Japanese Patent Application Laid-Open No. 2002-55457) discloses a method of forming a pattern by radiation or electron beam having a short wavelength (less than about 160 nm) using a photoresist composition containing 5% by mass or more of an acid generator. Is disclosed.

Patent Document 3 (Japanese Patent Laid-Open No. 2003-177537) discloses a resist composition for positive electron beam, X-ray or EUV containing a resin having an acetal structure having an ether linking group.
Further, Patent Document 4 (Japanese Patent Laid-Open No. 2000-347412) discloses a resist material containing a dendripolymer or a hyperbranched polymer of a hydroxystyrene derivative.

  However, even with the above technology, the present situation is that the resolution, line edge roughness, sensitivity, and pattern shape are not satisfied at the same time.

  Further, when EUV is used as a light source, the wavelength of light belongs to the extreme ultraviolet region and has high energy, and thus there has been a problem such as a decrease in contrast due to concerted photochemical reactions such as negation due to EUV light.

  Also, unlike conventional light sources, when high-energy rays such as EUV light are irradiated, the compounds in the resist film are destroyed by fragmentation and volatilized as low-molecular components during exposure, contaminating the environment inside the exposure machine. Outgassing problems become significant. Various researches have been conducted on the reduction of outgas, and a radical trap agent that suppresses the volatilization of low-molecular compounds by providing a topcoat layer (see, for example, Patent Document 5) or a polymer that suppresses decomposition of a polymer. Various attempts such as addition (see, for example, Patent Document 6) have been tried, and an contrivance for reducing the outgas is also desired for the acid generator.

  Moreover, the conventional resist composition is desired to be further improved in terms of PEB temperature dependency.

JP-A-4-219757 JP 2002-55457 A JP 2003-177537 A Japanese Patent Application Laid-Open No. 2000-347412 European Patent No. 1480078 specification US Pat. No. 6,680,157

  An object of the present invention is to solve the problems of performance improvement technology in microfabrication of a semiconductor device using high energy rays, particularly KrF excimer laser, electron beam, X-ray or EUV light, and the sensitivity, resolution, line edge It is an object of the present invention to provide a positive resist composition that simultaneously satisfies roughness, pattern shape, contrast, PEB temperature dependency, and outgas during exposure, and a pattern forming method using the same.

一般式（ＢＩ）において、
Ｒ^1b、Ｒ^2b及びＲ^3bは、各々独立に、アルキル基、シクロアルキル基又はアリール基を表す。ただし、化合物（Ｒ^1b−Ｈ）、（Ｒ^2b−Ｈ）、及び（Ｒ^3b−Ｈ）の沸点は、全て１９０℃以上（１気圧）である。Ｘ^-は、非求核性アニオンを表す。
＜２＞
前記一般式（ＢＩ）において、Ｒ ^1b 、Ｒ ^2b 及びＲ ^3b が、アリール基を表し、化合物（Ｒ ^1b −Ｈ）、（Ｒ ^2b −Ｈ）、及び（Ｒ ^3b −Ｈ）の沸点が、全て２００℃以上（１気圧）であることを特徴とする＜１＞に記載のポジ型レジスト組成物。
＜３＞
前記一般式（ＢＩ）において、Ｒ ^1b 〜Ｒ ^３ｂ それぞれに含まれる炭素数が8個以下であることを特徴とする＜１＞又は＜２＞に記載のポジ型レジスト組成物。
＜４＞
更に、プロトンアクセプター性官能基を有し、且つ、活性光線又は放射線の照射により分解してプロトンアクセプター性が低下、消失、又はプロトンアクセプター性から酸性に変化した化合物を発生する化合物を含有することを特徴とする＜１＞〜＜３＞のいずれか１項に記載のポジ型レジスト組成物。
＜５＞
ポリマー（Ａ）が、くし型ポリマーであることを特徴とする＜１＞〜＜４＞のいずれか１項に記載のポジ型レジスト組成物。
＜６＞
ポリマー（Ａ）を形成するポリマー鎖のうち少なくとも１つが、ビニル型繰り返し単位からなることを特徴とする＜１＞〜＜５＞のいずれか一項に記載のポジ型レジスト組成物。
＜７＞
該ビニル型繰り返し単位として、スチレン誘導体に由来する繰り返し単位または／および（メタ）アクリル酸誘導体に由来する繰り返し単位を有することを特徴とする＜６＞に記載のポジ型レジスト組成物。
＜８＞
一般式（ＢＩ）において、Ｒ^1b、Ｒ^2b及びＲ^3bのそれぞれに含まれる炭素数が８以下であることを特徴とする＜１＞〜＜７＞のいずれか一項に記載のポジ型レジスト組成物。
＜９＞
＜１＞〜＜８＞のいずれか一項に記載のポジ型レジスト組成物から形成されるレジスト膜。
＜１０＞
＜９＞に記載のレジスト膜を露光、現像することを特徴とするパターン形成方法。
本発明は、上記＜１＞〜＜１０＞に記載の構成を有するものであるが、以下、他の事項も含めて記載している。 That is, the present invention has the following configuration.
<1>
(A) at least one via the branching unit having a polymer chain of three or more, the polymer over及 beauty of increasing the solubility in an alkali developing solution under action of acid (B) an actinic ray or a compound which generates an acid when exposed to radiation as a positive resist composition, characterized by containing a compound represented by the following general formula (BI).

In general formula (BI):
R ^1b , R ^2b and R ^3b each independently represents an alkyl group, a cycloalkyl group or an aryl group. However, the boiling point of the compound ^{(R 1b -H), (R} 2b -H), and (R ^3b -H) are all 1 9 0 ° C. or more (1 atm). X ⁻ represents a non-nucleophilic anion .
<2>
In the general formula (BI), R ^1b , R ^2b, and R ^3b represent an aryl group , and the boiling points of the compounds (R ^1b -H), (R ^2b -H), and (R ^3b -H) are all The positive resist composition as described in <1>, which is 200 ° C. or higher (1 atm).
<3>
The positive resist composition as described in <1> or <2>, wherein in the general formula (BI), R ^{1b to} R ^3b each have 8 or less carbon atoms.
<4>
In addition, it contains a compound that has a proton acceptor functional group and generates a compound that decomposes upon irradiation with actinic rays or radiation to decrease, disappear, or change the proton acceptor property to acidic. it characterized by <1> - positive resist composition according to any one of <3>.
<5>
Polymer (A) is, it characterized in that it is a comb polymer <1> - positive resist composition according to any one of <4>.
<6>
At least one of the polymer chain forming a polymer (A), but you characterized by comprising a vinyl-type repeating unit <1> - positive resist composition according to any one of <5>.
<7>
As the vinyl-type repeating units, repeating units and / or (meth) The positive resist composition according to you characterized by having a repeating unit derived from acrylic acid derivative <6> derived from styrene derivatives.
<8>
In the general formula (BI), R ^1b, you wherein the number of carbon atoms contained in each of R ^2b and R ^3b is 8 or less <1> to positive according to any one of <7> Resist composition.
<9>
A resist film formed from the positive resist composition according to any one of < 1> to <8>.
<10>
< 9> A pattern forming method comprising exposing and developing the resist film according to [9].
Although this invention has the structure as described in said <1>-<10>, it is described below also including other matters.

(1) (A) a polymer having three or more polymer chains via at least one branching portion, and a polymer whose solubility in an alkaline developer is increased by the action of an acid; and (B) an acid is generated by irradiation with actinic rays or radiation. As a compound, the following general formula (BI)
A positive resist composition comprising a compound represented by the formula:

In general formula (BI):
R ^1b , R ^2b and R ^3b each independently represents an alkyl group, a cycloalkyl group or an aryl group. However, the boiling points of the compounds (R ^1b —H), (R ^2b —H), and (R ^3b —H) are all 160 ° C. or higher (1 atm).
X ⁻ represents a non-nucleophilic anion.

  (2) Furthermore, a compound having a proton acceptor functional group and decomposed by irradiation with actinic rays or radiation to reduce or disappear the proton acceptor, or generate a compound changed from proton acceptor to acidic The positive resist composition as described in (1), which comprises a compound.

  (3) The positive resist composition as described in (1) or (2), wherein the polymer (A) is a comb polymer.

  (4) The positive resist composition as described in (1) or (2), wherein the polymer (A) is a star polymer.

  (5) The positive resist composition as described in (1) or (2), wherein the polymer (A) is a hyperbranched polymer.

  (6) The positive resist composition as described in any one of (1) to (5), wherein at least one of the polymer chains forming the polymer (A) is composed of a vinyl-type repeating unit.

  (7) The positive resist composition as described in (6), wherein the vinyl-type repeating unit includes a repeating unit derived from a styrene derivative and / or a repeating unit derived from a (meth) acrylic acid derivative.

  (8) A pattern forming method comprising: forming a resist film from the positive resist composition according to any one of (1) to (7); and exposing and developing the resist film.

Further preferred embodiments include the following configurations.
(9) The surfactant according to (1) to (7) above, wherein the surfactant is contained in a ratio of 0.0001% by mass to 2% by mass per 100% by mass of the solid content in the positive resist composition. The positive resist composition according to any one of the above.
(10) The polymer (A) contains a repeating unit having a group that decomposes by the action of an acid and a group having at least one of an alicyclic ring and an aromatic ring is eliminated to form an alkali-soluble group. The positive resist composition according to any one of (1) to (7) and (9) above.
(11) The positive resist composition as described in any one of (1) to (7), (9) and (10) above, which is exposed by electron beam, X-ray or EUV.
(12) The positive resist composition as described in any one of (1) to (7), (9) and (10), wherein the actinic ray or radiation is ultraviolet light having a wavelength of 100 to 300 nm.
(13) The positive resist composition as described in any one of (1) to (7), (9) and (10), wherein the actinic ray or radiation is an ultraviolet ray having a wavelength of 200 to 300 nm.

(14) The positive resist composition as described in any one of (1) to (7) and (9) to (13), which contains an organic basic compound (C).
(15) The component (B) contains (B1) a compound capable of generating an organic sulfonic acid by the action of actinic rays or radiation. (1) to (7) and (9) to (14) The positive resist composition according to any one of the above.
(16) (1) to (7) and (9) to (14), wherein the component (B) contains (B2) a compound capable of generating an arylsulfonic acid by the action of actinic rays or radiation. The positive resist composition according to any one of the above.
(17) The positive resist composition as described in any one of (1) to (7) and (9) to (16), which further contains a solvent.

(18) The positive resist composition as described in (17) above, which contains propylene glycol monomethyl ether acetate as the solvent.
(19) The positive resist composition as described in (18), further containing propylene glycol monomethyl ether as the solvent.
(20) Furthermore, the acetal compound represented by the following general formula (A) and / or the acetal compound represented by the general formula (B) is contained (1) to (7) and (9) -The positive resist composition in any one of (19).

In general formulas (A) and (B),
R ₁ ′ and R ₂ ′ each independently represents an organic group.

According to the present invention, a positive resist composition is excellent in sensitivity and resolving power as well as pattern shape and line edge roughness with respect to pattern formation by irradiation with actinic rays or radiation, preferably irradiation with electron beam, EUV light or X-ray. An object and a pattern forming method using the same can be provided.
Furthermore, the present invention provides a positive resist composition that has sufficiently good contrast under EUV light irradiation, has no problem of outgassing during exposure, and has good PEB temperature dependency, and a pattern forming method using the same. it can.

Hereinafter, the positive resist composition of the present invention will be described in detail.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. . For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

[1] (A) A polymer (hereinafter referred to as “acid-decomposable polymer (A) having three or more polymer chains via at least one branch portion”, which is decomposed by the action of an acid to increase the solubility in an alkaline developer. ) ")
The acid-decomposable polymer (A) is a resin (acid-decomposable resin) that has three or more polymer chains via at least one branch part and decomposes by the action of an acid to increase the solubility in an alkali developer. And a repeating unit having a group (acid-decomposable group) that decomposes by the action of an acid as described later and generates an alkali-soluble group such as a carboxy group or a hydroxyl group.

The acid-decomposable polymer (A) used in the present invention is a so-called branched polymer having three or more polymer chains via at least one branched part, and one conventionally used polymer chain. The structure is different from that of a linear polymer composed only of Regarding branched polymers, edited by Koji Ishizu, “Nanotechnology of Branched Polymers” (IPC) Chapter 1, Chapter 6, Chapter 7 and Takuhei Nose, Seiichi Nakahama, Kiyozo Miyata “Graduate Polymer Chemistry” ( Kodansha) p. 39. In general, since a branched polymer has physical properties derived from a branched (branched) structure, it is known that a solution and a solid physical property are greatly different from a normal linear polymer.
The molecular weight of each polymer chain is preferably 50 or more, more preferably 100 or more, and still more preferably 200 or more.
The polymer chain has a plurality of repeating units.

Examples of the branched polymer include a comb polymer (A1), a star polymer (A2), and a hyperbranched polymer (A3). The comb polymer is a branched polymer in which a large number of branches appear on the trunk at equal intervals. Among comb polymers, those having a side chain (branch) having a different configuration or arrangement from the main chain (trunk) are called graft polymers. A star-shaped polymer is a branched polymer with a structure in which atoms or atomic groups are the core and a plurality of three or more branched chains extend radially. A hyperbranched polymer is a total of two types of substituents in one molecule. It is a multi-branched polymer obtained by polymerization of so-called AB _x type molecules having three or more. For the comb type, graft, star type and hyperbranched polymer, see “Graduate Polymer Chemistry” p. 39-43.

Examples of the method for confirming the presence or absence of the branched chain of the branched polymer include a method by GPC (gel permeation chromatography) -light scattering measurement. That is, GPC / MALLS (multi-angle light scattering) measurement of the polymer is performed, and at each elution position, <R ² > ^1/2 (square root of the mean square of the radius R) is obtained from the slope of the scattered light intensity, and the scattered light The weight average molecular weight Mw is obtained from the intensity intercept, the logarithm of <R ² > ^1/2 and Mw is plotted, and the slope α is calculated by the least square method. A slope α _x of a certain polymer X and a linear polymer having the same monomer composition as that of the polymer X and having a similar copolymer composition (for example, an error in the copolymer composition is within 10%, that is, in each of the two polymers When the slope α _{l in} the case of the difference in content (mol%) of the same repeating unit containing the largest amount (within 10 mol%) is compared, when (α _l / α _x )> 1, the polymer X is branched When a chain is present and the value of (α _l / α _x ) is larger than 1, the proportion of branching in the polymer X molecule is larger. When (α _l / α _x ) ≦ 1, the polymer X has a branched chain. Evaluate not. When the slope obtained from the above plot is α _b when the branched polymer of the present invention is used, the value of (α _l / α _b ) is preferably 1.02 or more, more preferably 1.03 or more, still more preferably Is 1.04 or more, most preferably 1.05 or more.

  Regarding polymerization of each polymer chain (not limited to the trunk and branches) forming the branched polymer, conventional techniques (radical polymerization, cationic polymerization, anionic polymerization, or living radical polymerization, living cationic polymerization, living anionic polymerization, chain polymerization) Chain polymerization is preferred. That is, each polymer chain forming the branched polymer is preferably composed of a vinyl-type repeating unit. As the polymerization method, radical polymerization and living radical polymerization are particularly preferable among chain polymerizations.

  The vinyl-type repeating unit is preferably a styrene derivative represented by the following formula (I) or a (meth) acrylic acid derivative represented by the following formula (II).

In the formula (I), Z represents a hydrogen atom or an organic group (acid-decomposable or non-acid-decomposable). Y represents a hydrogen atom or an organic group (acid-decomposable or non-acid-decomposable). R ₁ represents a hydrogen atom, a halogen atom or an alkyl group. a, b and c are integers and satisfy a ≧ 0, b ≧ 0, c ≧ 0, and 0 ≦ a + b + c ≦ 5.
Among the organic groups of Z, as the acid-decomposable group, —C (R ₁₁ ) (R ₁₂ ) (R ₁₃ ), —C (R ₁₄ ) (R ₁₅ ) (OR ₁₆ ), — [C (R ₁₇ ) (R _{18)] n -CO-OC (R 11)} (R 12) (R 13) are preferred. R _{11 to} R ₁₃ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group. R ₁₄ , R ₁₅ , R ₁₇ and R ₁₈ each independently represent a hydrogen atom or an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group. R ₁₆ represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group. Two of R ₁₁ , R ₁₂ and R ₁₃ , two of R ₁₄ , R ₁₅ and R ₁₆ , or two of R ₁₇ and R ₁₈ may be bonded to form a ring.
The alkyl group, the cycloalkyl group, the alkenyl group, and the aralkyl group each include —O—, —S—, —CO ₂ —, —CO—, —CONH—, —SO ₂ —, in each alkylene chain. -SO- or a combination thereof may be included.
Of the organic groups of Y, the acid-decomposable group is preferably —C (R ₁₁ ) (R ₁₂ ) (R ₁₃ ) or —C (R ₁₄ ) (R ₁₅ ) (OR ₁₆ ).

In formula (II), R ₂ represents a hydrogen atom or an alkyl group. X ₁ represents —ORa, —SRb or —N (Rc) Rb. Ra represents a hydrogen atom or an organic group (acid-decomposable or non-acid-decomposable). Rb represents a hydrogen atom or a non-acid-decomposable organic group. Rc represents a hydrogen atom or an alkyl group.
Among the organic groups of Ra, the acid-decomposable group includes -C (R ₁₁ ) (R ₁₂ ) (R ₁₃ ), -C (R ₁₄ ) (
R ₁₅ ) (OR ₁₆ ) is preferred.

The non-acid-decomposable organic group for Ra or Rb is an organic group that is not decomposed by the action of an acid, such as an alkyl group, a cycloalkyl group, an aryl group, that is not decomposed by the action of an acid, Examples thereof include an aralkyl group, an alkoxy group, an alkoxycarbonyl group, an amide group, and a cyano group. The alkyl group and cycloalkyl group preferably have 1 to 10 carbon atoms. For example, methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, hexyl group, 2-ethylhexyl group, octyl group, cyclohexane A propyl group, a cyclobutyl group, a cyclohexyl group, an adamantyl group, etc. can be mentioned. The aryl group is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthracenyl group. The aralkyl group is preferably an aralkyl group having 6 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a cumyl group. The alkoxy group in the alkoxy group and the alkoxycarbonyl group is preferably an alkoxy group having 1 to 5 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, and an isobutoxy group.
The alkyl group of R ₂ and Rc is preferably an alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group or the like is preferable. Can be mentioned.

  Examples of the substituent that each of the above groups may have include, for example, those having active hydrogen such as amide group, ureido group, urethane group, hydroxyl group, carboxyl group, and halogen atoms (fluorine atom, chlorine atom, bromine atom). , Iodine atom), alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), thioether group, acyl group (acetyl group, propanoyl group, benzoyl group, etc.), acyloxy group (acetoxy group, propanoyloxy group, Benzoyloxy group etc.), alkoxycarbonyl group (methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group etc.), cyano group, nitro group and the like.

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

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

Next, a method for synthesizing each branched polymer will be described.
The method for synthesizing the comb polymer (A1) is not limited as long as it can synthesize a polymer having a structure that matches the definition of the comb polymer. Specifically, a polymerization starting point is generated in some way by a polymer that becomes a trunk, a monomer that is a trunk is polymerized therefrom, and branches are formed, and a polymer having an activity such as a living polymer is made into a backbone polymer. The method of making it react, the method of polymerizing the polymer (macromonomer) which has a polymerizable functional group at the terminal, etc. are mentioned. Of the above synthesis methods, the macromonomer method is preferred. The synthesis of macromonomers and the synthesis of polymers using them are described in Chapters 2 and 3 of “Macromonomer Chemistry and Industry” edited by Yuya Yamashita.

The synthesis method of star polymer (A2) includes the arm-first method in which a polymer that becomes a branched chain (branch) is first synthesized and then bonded to a nucleus atom or atomic group (hereinafter referred to as a core), The core-first method of synthesizing a polyfunctional initiator as a core and then synthesizing a polymer as a branch can be roughly divided into two types, and either method may be used. The method for synthesizing the star polymer (A2) is described in Chapter 1 of Koji Ishizu, “Nanotechnology of Branched Polymers” (IPC).
The synthesis method of the hyperbranched polymer (A3) is a method of applying a condensation reaction used in the synthesis of a linear polymer to a polyfunctional molecule (AB _x type monomer) when using condensation polymerization.
In the case of using chain polymerization, a method of synthesizing by a cationic polymerization or radical polymerization of a monomer in which a compound having a double bond has a reaction point serving as an initiator can be mentioned, and the latter is preferable. The method for synthesizing the hyperbranched polymer (A3) is described in Chapter 6 of Koji Ishizu, “Nanotechnology of Branched Polymers” (IPC).
In addition, when trying to synthesize a normal linear polymer by radical polymerization, it suddenly occurs due to the influence of chain transfer, etc., and it is generated from a growing radical having two or more radical active sites in one molecule. The polymer is completely different from the branched polymer of the present invention because the structure of the branched chain and the degree of generation of the branched chain are completely irregular and the structure cannot be defined. Such polymers are not included in the branched polymer of the present invention.

The acid-decomposable polymer (A) of the present invention does not contain a dendrimer. The acid-decomposable polymer (A) of the present invention contains a mixture of branched (branched) units and linear units, but dendrimers contain only branched repeating units regardless of generation. The acid-decomposable polymer (A) of the present invention is polydisperse and exhibits a molecular weight dispersity of at least 1.08, but the dendrimer is a monodisperse type (generally having a dispersity of less than about 1.02). It has a clear outline. Therefore, the acid-decomposable polymer (A) of the present invention and the dendrimer can be distinguished.

  Specific examples of the comb polymer (A1), star polymer (A2), and hyperbranched polymer (A3) are shown below, but are not limited thereto.

[Comb type polymer (A1)]

[Star polymer (A2)]

[Hyperbranched polymer (A3)]

  m1 is a number greater than 0, and each of m2, m, n1, n2, and n is a number greater than or equal to 0.

  The acid-decomposable polymer (A) preferably contains 5 mol% or more, more preferably 10 mol% or more of the repeating unit represented by the general formula (I) or the general formula (II) in all repeating units. Preferably it is 20 mol% or more. Moreover, you may contain another repeating unit collectively as needed. Examples of the monomer corresponding to the other repeating unit include maleic acid derivatives, maleic anhydride derivatives, (meth) acrylonitrile, vinyl pyrrolidone, vinyl pyridine, and vinyl acetate.

The acid-decomposable polymer (A) preferably contains 5 to 90 mol% of repeating units having an acid-decomposable group in all repeating units, more preferably 7 to 80 mol%, still more preferably 10 to 70 mol%. %. As the repeating unit having an acid-decomposable group, a structure in which Z is —C (R ₁₄ ) (R ₁₅ ) (OR ₁₆ ) in the formula (I), or X in the formula (II) is —ORa, and Ra is A structure of —C (R ₁₁ ) (R ₁₂ ) (R ₁₃ ) or —C (R ₁₄ ) (R ₁₅ ) (OR ₁₆ ) is preferred.

In addition, the acid-decomposable polymer (A) is a repeating unit having an acid-decomposable group, and a group having an alkali-soluble group by removing a group having at least one of an alicyclic ring and an aromatic ring by the action of an acid. It is preferable to have a unit.
As such a repeating unit, for the repeating units represented by the general formulas (I) and (II), an acid-decomposable organic group as Y and Z in the general formula (I) and the general formula (II) The case where the acid-decomposable organic group as Ra is a group having at least one of an alicyclic ring and an aromatic ring is mentioned.
The acid-decomposable polymer (A) is decomposed by the action of an acid, a group having at least one of an alicyclic ring and an aromatic ring is eliminated, and the content of the repeating unit having a group that generates an alkali-soluble group is acid-decomposable. It is 3-95 mol% normally with respect to all the repeating units which comprise a polymer (A), Preferably it is 5-80 mol%.
Further, the acid-decomposable organic group as Y and Z in the general formula (I) and the acid-decomposable organic group as Ra in the general formula (II) preferably have a total carbon number of 4 to 50, preferably 5 to 45. Is more preferable, and 6 to 40 is particularly preferable.

  As a method for introducing an acid-decomposable group in the acid-decomposable polymer (A), a method in which a monomer in which an alkali-soluble group such as a phenolic hydroxyl group or a carboxyl group is previously protected with an acid-decomposable group is copolymerized and introduced, There is a method in which a polymer skeleton containing an alkali-soluble group is constructed, and then the alkali-soluble group is introduced after protecting with an acid-decomposable group. Either method may be used. An example of the latter method is a method in which a part of the phenolic hydroxyl group of a polymer having a phenolic hydroxyl group is obtained by an acetalization reaction using a corresponding vinyl ether compound and an acid catalyst. An acetal group can be introduced by the method described in JP-A-5-249682, JP-A-8-123032 and JP-A-10-221854. It is also possible to introduce a desired acetal group using S. Malik's acetal exchange reaction described in J. Photo Polym. Sci. Tech., 11 (3) 431 (1998).

That is, it is a method in which a polymer having a phenolic hydroxyl group is reacted with a vinyl ether compound represented by the following general formula (C) and an alcohol compound represented by the following general formula (D) in the presence of an acid catalyst. Here, as an acid catalyst, p-toluenesulfonic acid, p-toluenesulfonic acid pyridinium salt, etc. can be used. In this method, for example, as shown in the following reaction formula, a resin having a phenolic hydroxyl group, a vinyl ether compound represented by the following general formula (C) and an alcohol compound represented by the following general formula (D) are present in the presence of an acid catalyst. By reacting, only R ₃ ′ and R ₄ ′ or R ₄ ′ can be introduced as an acetal group as shown in the following general formula (F).

  The acid-decomposable polymer (A) may have one or more acid-decomposable groups.

The weight average molecular weight of the acid-decomposable polymer (A) is preferably 1000 to 200,000, and particularly preferably 1,500 to 20,000. That is, a molecular weight of 200,000 or less is preferable from the viewpoint of solubility and resolving power. Here, the weight average molecular weight is a value obtained by gel permeation chromatography (GPC) by light scattering detection.
The lower limit of the molecular weight dispersity (weight average molecular weight / number average molecular weight) of the acid-decomposable polymer (A) is 1.1 as described above. Regarding the upper limit, the higher the molecular weight dispersibility of the acid-decomposable polymer (A), the more likely the line edge roughness tends to be worse, so it is generally 3.0 or less, preferably 2.5 or less, more preferably 2 0.0 or less, more preferably 1.5 or less, and most preferably 1.3 or less.

  For such polymers with low molecular weight dispersibility, the polymer synthesis conditions (amount of polymerization solvent, amount of polymerization initiator) and polymer purification conditions (type / amount of reprecipitation solvent, number of reprecipitation operations) are variously changed. Can be obtained. For example, the molecular weight can be adjusted by changing the amount of the polymerization solvent or initiator, and the degree of dispersion of the resin can be reduced by changing the reprecipitation solvent or increasing the number of reprecipitation operations. As the reprecipitation solvent, it is preferable to use a mixture of two or more kinds of solvents, or to carry out the reprecipitation operation twice or more, and to perform the reprecipitation operation using a reprecipitation solvent in which two or more kinds of solvents are mixed. More preferably, it is performed more than once. Alternatively, a polymer having a low molecular weight dispersity can also be synthesized via a living anion, living radical, or living cation polymerization method.

(A1) when the comb polymer and the average degree of polymerization of the partial (backbone) of the stem and n _m,
n _m is the weight average molecular weight of the polymer may be any range as long as within the range described above. Further, when the average polymerization degree of the branched chains extending from the branching repeating units and n _b, preferably n _b ≧ 3 is the lower limit of n _b, more preferably n _b ≧ 5, more preferably from n _b ≧ 10. When _nb is too small, it becomes close to a normal linear polymer, and the effect of the present invention cannot be obtained. Regarding the upper limit of n _b, but the weight average molecular weight of the polymer may be any range as long as within the range of the, n _b ≦
15 _nm is preferred, more preferably n _b ≦ 13 _nm , and even more preferably n _b ≦ _{10 nm} . If _nb is too large with respect to _nm , the solubility is remarkably slow, and the effects of the present invention cannot be obtained.
Moreover, when the average number of branch points in one polymer molecule is x, x is 0.05 _nm ≦ x ≦ 0.
. 8 _nm is preferable, more preferably 0.1 _nm ≤ x ≤ 0.7 _nm , and still more preferably 0.8 _nm .
It is 15 _nm <= x <= 0.6 _nm . If x is too small, it becomes almost the same as a normal linear polymer, and if x is too large, the solubility is remarkably slow, and neither of the effects of the present invention can be obtained.

(A2) In the case of a star polymer, y is 3 or more by definition, where y is the average number of branches (branches) extending from the core portion. The upper limit of y is preferably y ≦ 20, more preferably y ≦ 17, and still more preferably y ≦ 14. Further, assuming that the average degree of polymerization of each branched chain is n _h , n _h is preferably 5 ≦ n _h ≦ 1000, more preferably 10 ≦ n _h ≦, assuming that the weight average molecular weight of the polymer falls within the above range. 800, more preferably 15 ≦ n _h ≦ 600. The molecular weight of the core portion is preferably 2000 or less, more preferably 1800 or less, and still more preferably 1500 or less. The lower limit of the molecular weight of the core portion is not particularly limited. However, when the value of y is 4 or more, a structure in which the connecting portions with a plurality of branched chains existing in the core portion are separated and are not close to each other is preferable. . Specifically, a structure having one or more monocyclic or polycyclic aromatic rings is preferable.

  (A3) In the case of a hyperbranched polymer, the average molar ratio of a repeating unit having a branching point and a repeating unit having no branching point in one polymer molecule (for example, in the structure of the hyperbranched polymer exemplified above) Is (average of (m1 + m2 + ...) :( n1 + n2 + ...)) is usually 1:99 to 99: 1, preferably 5:95 to 95: 5, more preferably 10:90 to 90:10. It is.

  As content in the composition of an acid-decomposable polymer (A), it is 70-98 mass% normally with respect to the mass of the total solid of this composition, Preferably it is 75-96 mass%, More preferably Is 80-96 mass%.

[2] (B) Compound Represented by General Formula (BI) The positive resist composition of the present invention is represented by the following general formula (BI) as a compound that generates an acid upon irradiation with actinic rays or radiation. Contains compounds.

In general formula (BI),
R ^1b , R ^2b and R ^3b each independently represents an alkyl group, a cycloalkyl group or an aryl group. However, the boiling points of the compounds (R ^1b —H), (R ^2b —H) and (R ^3b —H) are all 160 ° C. or higher (1 atm).
X ⁻ represents a non-nucleophilic anion.

In the general formula (BI), the alkyl group represented by R ^{1b to} R ^3b is preferably an alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a sec-butyl group. Group, t-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group and the like.
As a cycloalkyl group of R ^{< 1b} > -R < ^3b >, a C3-C15 cycloalkyl group is preferable, for example, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group etc. can be mentioned.
The aryl group for R ^{1b to} R ^3b is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group and a naphthyl group.
R ^{1b to} R ^3b are preferably aryl groups.

The alkyl group, cycloalkyl group and aryl group of R ^{1b to} R ^3b may further have a substituent. Examples of the substituent include a halogen atom and an alkyl group (here, a cycloalkyl group and a bicycloalkyl group). , Including tricycloalkyl groups), alkenyl groups (including cycloalkenyl groups and bicycloalkenyl groups here), alkynyl groups, aryl groups, cyano groups, hydroxyl groups, nitro groups, carboxyl groups, alkoxy groups, aryloxy groups Silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino Group, mercapto group, alkylthio group, arylthio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, imide group, silyl group And ureido groups.

Further, the substituent for R ^{1b to} R ^3b is preferably an aryl group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, acyloxy group, aminocarbonylamino group, alkoxycarbonylamino group. , Aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, An aryloxycarbonyl group, an alkoxycarbonyl group, and a carbamoyl group, particularly preferably a cyano group, an alkoxy group, an acyl group, an alkoxycarbonyl group, and a carbamoyl group.

The number of carbon atoms contained in each of R ^{1b to} R ^3b is preferably 12 or less, more preferably 8 or less, and particularly preferably 7 or less.

Compounds (R ^1b —H), (R ^2b —H) and (R ^3b —H) are compounds formed by bonding a hydrogen atom to a monovalent group represented by R ^{1b to} R ^3b , respectively. In other words, the compound represented by the general formula (AII) corresponds to a compound generated as a decomposition product upon irradiation with EUV light.
The boiling points of the compounds (R ^1b —H), (R ^2b —H) and (R ^3b —H) at 1 atm are all 160 ° C. or higher, preferably 180 ° C. or higher, and more preferably 190 ° C. It is more than 200 degreeC, Most preferably, it is 200 degreeC or more.

X ⁻ is a non-nucleophilic anion, and the non-nucleophilic anion is an anion having a remarkably low ability to cause a nucleophilic reaction, and is an anion capable of suppressing degradation over time due to an intramolecular nucleophilic reaction. Examples of the non-nucleophilic anion include a sulfonate anion, a carboxylate anion, and a bissulfonylimide anion, and a sulfonate anion is preferable. Examples of the sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.

  Specific preferred sulfonate anions include trifluoromethane sulfonate anion, pentafluoroethane sulfonate anion, heptafluoropropane sulfonate anion, perfluorobutane sulfonate anion, perfluorohexane sulfonate anion, perfluorooctane sulfonate. Anion, pentafluorobenzenesulfonate anion, 3,5-bistrifluoromethylbenzenesulfonate anion, 2,4,6-triisopropylbenzenesulfonate anion, perfluoroethoxyethanesulfonate anion, 2,3,5,6- Examples include tetrafluoro-4-dodecyloxybenzenesulfonate anion.

  Hereinafter, although the specific example of a cation part in the compound represented by general formula (BI) is given, this invention is not limited to this.

Regarding the compound (R ^1b —H), the compound (R ^2b —H), and the compound (R ^3b —H) in the specific examples of the cation moiety, the following table shows the boiling point (measured value) of the compound and the literature value of the boiling point. It is shown in 1. For the literature value of the boiling point, “Dictionary of compounds (Asakura Shoten Co., Ltd., November 20, 1997, first edition)” was referred to. The boiling point (measured value) is determined by the method described in the 4th edition Experimental Chemistry Course (editor: The Chemical Society of Japan, publisher: Maruzen Co., Ltd., issued on February 5, 1992). Was measured.

  Specific examples of the compound represented by the general formula (BI) are shown below, but the present invention is not limited thereto.

The compound represented by the general formula (BI) (also referred to as “compound (BI)”) can be synthesized by a known method after selecting substituents in R ^{1b to} R ^3b to satisfy the above requirements. it can. Commercially available products can also be used.

  The content of the compound (BI) in the positive resist composition of the present invention is preferably 0.001 to 40% by mass, more preferably 0.01 to 20% by mass, based on the total solid content of the composition. Especially preferably, it is 0.1-10 mass%. In addition, one type of acid generator may be used, or two or more types may be used.

(Combination acid generator)
In the present invention, in addition to the compound (BI), a compound (acid generator) that decomposes upon irradiation with actinic rays or radiation to generate an acid (acid generator) may be further used.

  The amount of the photoacid generator that can be used in combination is usually 100/0 to 20/80, preferably 100/0 to 40/60, and more preferably in molar ratio (compound (BI) / other acid generator). 100/0 to 50/50.

  As such photoacid generators that can be used in combination, they are used in photocationic photoinitiators, photoinitiators of radical photopolymerization, photodecolorants of dyes, photochromic agents, or microresists. Known compounds that generate acids upon irradiation with actinic rays or radiation and mixtures thereof can be appropriately selected and used.

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

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

  Among the compounds capable of decomposing upon irradiation with actinic rays or radiation that may be used in combination, preferred compounds include compounds represented by the following general formulas (ZI), (ZII), and (ZIII). it can.

In the above 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 to 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. This improves the temporal stability of the resist.

  Examples of the sulfonate anion include an alkyl sulfonate anion, an aryl sulfonate anion, and a camphor sulfonate anion.

  Examples of the carboxylate anion include an alkylcarboxylate anion, an arylcarboxylate anion, and an aralkylcarboxylate anion.

  The alkyl moiety in the alkyl sulfonate anion may be an alkyl group or a cycloalkyl group, and preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms, such as a methyl group or an ethyl group. 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, boronyl group and the like.

  The aryl group in the aryl 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.

  Examples of the substituent of the alkyl group, cycloalkyl group and aryl group in the alkyl sulfonate anion and aryl sulfonate anion include, for example, a nitro group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group, Hydroxyl group, amino group, cyano group, alkoxy group (preferably 1 to 5 carbon atoms), cycloalkyl group (preferably 3 to 15 carbon atoms), aryl group (preferably 6 to 14 carbon atoms), alkoxycarbonyl group (preferably May include 2 to 7 carbon atoms, an acyl group (preferably 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably 2 to 7 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.

  Examples of the alkyl moiety in the alkylcarboxylate anion include the same alkyl group and cycloalkyl group as in the alkylsulfonate anion.

  Examples of the aryl group in the arylcarboxylate anion include the same aryl groups as in the arylsulfonate anion.

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

  Examples of the alkyl group, cycloalkyl group, aryl group and aralkyl group substituent in the alkylcarboxylate anion, arylcarboxylate anion and aralkylcarboxylate anion include, for example, the same halogen atom, alkyl group as in the arylsulfonate anion, A cycloalkyl group, an alkoxy group, an alkylthio group, etc. can be mentioned.

  Examples of the sulfonylimide anion include saccharin anion.

The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methyl anion is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, An isobutyl group, a sec-butyl group, a pentyl group, a neopentyl group, and the like can be given. Examples of the substituent of these alkyl groups include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, and an alkylthio group, and an alkyl group substituted with a fluorine atom is preferable.

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

Examples of the non-nucleophilic anion of Z ⁻ include an alkanesulfonic acid anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, an arylsulfonic acid anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group having a fluorine atom And a tris (alkylsulfonyl) methide anion in which the alkyl group is substituted with a fluorine atom. The non-nucleophilic anion is particularly preferably a perfluoroalkanesulfonic acid anion having 4 to 8 carbon atoms, a benzenesulfonic acid anion having a fluorine atom, most preferably nonafluorobutanesulfonic acid anion, perfluorooctanesulfonic acid anion, penta Fluorobenzenesulfonate anion, 3,5-bis (trifluoromethyl) benzenesulfonate anion.

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include, for example, a compound described later (Z1-1
), (Z1-2) and (Z1-3), the corresponding groups.

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

  More preferable examples of the (ZI) component include compounds (Z1-1), (Z1-2), and (Z1-3) described below.

Compound (Z1-1) 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 R ₂₀₁
Some of to R ₂₀₃ is an aryl group and the remainder may be an alkyl group or a cycloalkyl group.

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

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. 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 hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, most 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 (Z1-2) will be described.
Compound (Z1-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

The organic group 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, most 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 alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, butyl group, pentyl 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 hydroxyl group, a cyano group, or a nitro group.

Two members out of R _{201 to} R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. 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).

  The compound (Z1-3) is a compound represented by the following general formula (Z1-3), and is a compound having a phenacylsulfonium salt structure.

R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c represent a hydrogen atom, an alkyl group, or a cycloalkyl group.
R _x and R _y each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom, a sulfur atom, an ester bond, and an amide bond. May be included.

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

The alkyl group as R _{1c to} R _{5c 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. The cycloalkyl group is, for example, a cyclic group 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 one of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _1c to R _5c is 2 to 2. 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group and cycloalkyl group as R _x and R _y include the same alkyl group and cycloalkyl group as in R _{1c to} R _5c, and include a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxy group. A carbonylmethyl group is more preferred.

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 _5c .

Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as in R _{1c to} R _5c .

Examples of the group formed by combining R _x and R _y include a butylene group and a pentylene group.

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.

In the general formula (ZII) and (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.

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).

The R ₂₀₄ to R ₂₀₇ are substituents which may have, 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 (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

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

  Of the compounds that decompose upon irradiation with actinic rays or radiation that may be used in combination, preferred compounds further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI). be able to.

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

R ₂₀₆ , R ₂₀₇ and R _{208 each} 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 compounds that may be used in combination and decompose upon irradiation with actinic rays or radiation to generate an acid, compounds represented by general formulas (ZI) to (ZIII) are more preferable.
Further, as a compound that decomposes upon irradiation with actinic rays or radiation that may be used in combination, a compound that generates a sulfonic acid having one sulfonic acid group is preferable, and a monovalent perfluoroalkanesulfone is more preferable. A compound that generates an acid, or a compound that generates an aromatic sulfonic acid substituted with a fluorine atom or a group containing a fluorine atom, particularly preferably a sulfonium salt of monovalent perfluoroalkanesulfonic acid.

  Of the compounds that decompose upon irradiation with actinic rays or radiation that may be used in combination, particularly preferred examples are listed below.

Alkali-soluble resin In addition to the acid-decomposable polymer (A), an alkali-soluble resin that does not contain an acid-decomposable group can be added to the resist composition of the present invention, thereby improving sensitivity. .

An alkali-soluble resin that does not contain an acid-decomposable group (hereinafter simply referred to as “alkali-soluble resin”) is a resin that is soluble in an alkali developer, and is an acid-decomposable group in the acid-decomposable polymer (A) of the present invention. In addition to resins that are all deprotected in terms of form, polyhydroxystyrene, novolak resins and derivatives thereof can be preferably exemplified. In addition to these, a copolymer resin containing a p-hydroxystyrene unit can also be used if it is alkali-soluble.

  In the present invention, the addition amount in the composition of the alkali-soluble resin not containing the acid-decomposable group is preferably 2 to 60% by mass, more preferably, based on the total mass of the solid content of the composition. It is 5-30 mass%.

A compound that has a proton acceptor functional group and decomposes by irradiation with actinic rays or radiation to generate a compound whose proton acceptor property is lowered, disappears, or is changed from proton acceptor property to acidic. Type resist composition has a proton acceptor functional group and is decomposed by irradiation with actinic rays or radiation to generate a compound in which the proton acceptor property decreases, disappears, or changes from proton acceptor property to acidity It is preferable to contain the compound (henceforth "compound (A)") which carries out.

  The compound (A) is generated by decomposing upon irradiation with actinic rays or radiation, and the proton acceptor property is lowered, disappears, or is changed from the proton acceptor property to an acid by the following general formula (AI). Mention may be made of the compounds represented.

In general formula (AI),
A represents a divalent linking group.
Q represents a sulfo group (—SO ₃ H) or a carboxyl group (—CO ₂ H).
X represents —SO ₂ — or —CO—.
n represents 0 or 1.
B represents a single bond, an oxygen atom or -N (Rx)-.
Rx represents a hydrogen atom or a monovalent organic group.
R represents a monovalent organic group having a proton acceptor functional group or a monovalent organic group having an ammonium group.

  The divalent linking group in A is preferably a divalent linking group having 2 to 12 carbon atoms, and examples thereof include an alkylene group and a phenylene group. More preferably, it is an alkylene group having at least one fluorine atom, and a preferable carbon number is 2 to 6, more preferably 2 to 4. The alkylene chain may have a linking group such as an oxygen atom or a sulfur atom. The alkylene group is particularly preferably an alkylene group in which 30 to 100% of the number of hydrogen atoms are substituted with fluorine atoms, and more preferably, the carbon atom bonded to the Q site has a fluorine atom. Further, a perfluoroalkylene group is preferable, and a perfluoroethylene group, a perfluoropropylene group, and a perfluorobutylene group are more preferable.

The monovalent organic group in Rx preferably has 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group.
The alkyl group for Rx may have a substituent, and preferably has 1 to 1 carbon atoms.
20 linear and branched alkyl groups, which may have an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group, etc. And a branched alkyl group such as isopropyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, 2-ethylhexyl group.
Examples of the alkyl group having a substituent include groups in which a linear or branched alkyl group is substituted with a cycloalkyl group (for example, an adamantylmethyl group, an adamantylethyl group, a cyclohexylethyl group, a camphor residue, etc.). .
The cycloalkyl group in Rx may have a substituent, preferably a cycloalkyl group having 3 to 20 carbon atoms, and may have an oxygen atom in the ring. Specific examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
The aryl group in Rx may have a substituent and is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group and a naphthyl group.
The aralkyl group in Rx may have a substituent, preferably an aralkyl group having 7 to 20 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, a naphthylmethyl group, and a naphthylethyl group.
The alkenyl group in Rx may have a substituent, and examples thereof include a group having a double bond at an arbitrary position of the alkyl group mentioned as Rx.

  The proton acceptor functional group in R is a group capable of electrostatically interacting with protons or a functional group having electrons, such as a functional group having a macrocyclic structure such as a cyclic polyether. Or a functional group having a nitrogen atom with a lone electron pair that does not contribute to π conjugation. The nitrogen atom having a lone electron pair that does not contribute to π conjugation is, for example, a nitrogen atom having a partial structure represented by the following general formula.

Preferable partial structures of the proton acceptor functional group include, for example, crown ether, azacrown ether, tertiary amine, secondary amine, primary amine, pyridine, imidazole, pyrazine structure and the like.
Preferred examples of the partial structure of the ammonium group include tertiary ammonium, secondary ammonium, primary ammonium, pyridinium, imidazolinium, and pyrazinium structures.
The group containing such a structure preferably has 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group.
The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, the alkyl group in the alkenyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group, which contain a proton acceptor functional group or an ammonium group in R, are represented by Rx. These are the same as the alkyl group, cycloalkyl group, aryl group, aralkyl group and alkenyl group mentioned.

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

When B is -N (Rx)-, R and Rx are preferably bonded to form a ring. By forming the ring structure, the stability is improved, and the storage stability of the composition using the ring structure is improved. The number of carbon atoms forming the ring is preferably 4 to 20, and may be monocyclic or polycyclic, and may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the ring.
Examples of the monocyclic structure include a 4-membered ring, a 5-membered ring, a 6-membered ring, a 7-membered ring, and an 8-membered ring containing a nitrogen atom. Examples of the polycyclic structure include a structure composed of a combination of two or three or more monocyclic structures. The monocyclic structure and polycyclic structure may have a substituent, for example, a halogen atom, a hydroxyl group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), Aryl group (preferably having 6 to 14 carbon atoms), alkoxy group (preferably having 1 to 10 carbon atoms), acyl group (preferably having 2 to 15 carbon atoms), acyloxy group (preferably having 2 to 15 carbon atoms), alkoxycarbonyl A group (preferably having 2 to 15 carbon atoms), an aminoacyl group (preferably having 2 to 20 carbon atoms) and the like are preferable. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having 1 to 15 carbon atoms). As for the aminoacyl group, examples of the substituent include 1 or 2 alkyl groups (preferably having 1 to 15 carbon atoms).

  Of the compounds represented by the general formula (AI), a compound in which the Q site is a sulfonic acid can be synthesized by using a general sulfonamidation reaction. For example, a method in which one sulfonyl halide part of a bissulfonyl halide compound is selectively reacted with an amine compound to form a sulfonamide bond and then the other sulfonyl halide part is hydrolyzed, or a cyclic sulfonic acid anhydride is used. It can be obtained by a method of ring-opening by reacting with an amine compound.

  Hereinafter, although the specific example of a compound represented by general formula (AI) is shown, this invention is not limited to this.

The compound represented by the following general formula (A-II), which is generated by the decomposition of the compound (A) by irradiation with actinic rays or radiation and the proton acceptor property is lowered, disappears, or is changed from proton acceptor property to acidity. ) Can be mentioned.

In general formula (A-II),
Q ₁ and Q ₂ each independently represents a monovalent organic group. However, either _one of Q ₁ and Q ₂ has a proton acceptor functional group. Q ₁ and Q ₂ may combine to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ and X ₂ each independently represent —CO— or —SO ₂ —.

In the general formula (A-II), the monovalent organic groups as Q ₁ and Q ₂ preferably have 1 to 40 carbon atoms, such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, An alkenyl group etc. can be mentioned.
The alkyl group in Q ₁ and Q ₂ may have a substituent, preferably a linear or branched alkyl group having 1 to 30 carbon atoms, and an oxygen atom, sulfur atom, nitrogen atom in the alkyl chain You may have. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group, etc. And a branched alkyl group such as isopropyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, 2-ethylhexyl group.
The cycloalkyl group in Q ₁ and Q ₂ may have a substituent, preferably a cycloalkyl group having 3 to 20 carbon atoms, and may have an oxygen atom or a nitrogen atom in the ring. Good. Specific examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
The aryl group in Q ₁ and Q ₂ may have a substituent, and preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group and a naphthyl group.
The aralkyl group in Q ₁ and Q ₂ may have a substituent, and preferably an aralkyl group having 7 to 20 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, or a naphthylethyl group. Is mentioned.
The alkenyl group for Q ₁ and Q ₂ may have a substituent, and examples thereof include a group having a double bond at an arbitrary position of the alkyl group.
Examples of the substituent that each group may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), and an aryl group (preferably Has 6 to 14 carbon atoms, an alkoxy group (preferably 1 to 10 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 10 carbon atoms), an alkoxycarbonyl group (preferably C2-C20), an aminoacyl group (preferably C2-C10) etc. are mentioned. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having 1 to 10 carbon atoms). As for the aminoacyl group, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 10). Examples of the alkyl group having a substituent include perfluoroalkyl groups such as a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, and a perfluorobutyl group.

One of the monovalent organic groups of Q ₁ and Q ₂ has a proton acceptor functional group.
The proton acceptor functional group is a group that can electrostatically interact with a proton or a functional group having a lone pair of electrons, such as a functional group having a macrocyclic structure such as a cyclic polyether, or π A functional group having a nitrogen atom having a lone electron pair with little conjugation contribution can be given. Examples of the nitrogen atom having a lone electron pair with little contribution of π conjugation include a nitrogen atom having a partial structure represented by the following general formula.

  Preferable partial structures of the proton acceptor functional group include, for example, crown ether, azacrown ether, tertiary amine, secondary amine, primary amine, pyridine, imidazole, pyrazine, aniline structure and the like. The group containing such a structure preferably has 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. The alkyl group, cycloalkyl group, aryl group, aralkyl group and alkenyl group are the same as those mentioned above.

  Examples of the substituent that each group may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), and an aryl group (preferably Has 6 to 14 carbon atoms, an alkoxy group (preferably 1 to 10 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 10 carbon atoms), an alkoxycarbonyl group (preferably C2-C20), an aminoacyl group (preferably C2-C20) etc. are mentioned. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 20). As for the aminoacyl group, examples of the substituent further include an alkyl group (preferably having 1 to 20 carbon atoms).

  The proton acceptor functional group may be substituted with an organic group having a bond that is cleaved by an acid. Examples of the organic group having a bond that can be cleaved by an acid include an amide group, an ester group (preferably a tertiary alkyloxycarbonyl group), an acetal group (preferably a 1-alkyloxy-alkyloxy group), and a carbamoyl group. Group, carbonate group and the like.

Examples of the structure in which Q ₁ and Q ₂ are bonded to form a ring and the formed ring has a proton acceptor functional group include, for example, an organic group of Q ₁ and Q ₂ is further an alkylene group, an oxy group And a structure bonded with an imino group or the like.

In general formula (A-II), it is preferable that at least one of X ₁ and X ₂ is —SO 2 —.

  The compound represented by the general formula (A-II) is preferably a compound represented by the following general formula (A-III).

In general formula (A-III),
Q ₁ and Q ₃ each independently represents a monovalent organic group. However, _one of Q ₁ and Q ₃ has a proton acceptor functional group. Q ₁ and Q ₃ may combine to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ , X ₂ and X ₃ each independently represent —CO— or —SO ₂ —.
A represents a divalent linking group.
B represents a single bond, an oxygen atom, or —N (Qx) —.
Qx represents a hydrogen atom or a monovalent organic group.
When B is —N (Qx) —, Q ₃ and Qx may combine to form a ring.
n represents 0 or 1.

Q ₁ has the same meaning as Q _{1 in} formula (A-II).
Examples of the organic group of Q ₃ include the same organic groups as Q ₁ and Q ₂ in formula (A-II).

  The divalent linking group in A is preferably a divalent linking group having 1 to 8 carbon atoms, for example, an alkylene group having 1 to 8 carbon atoms, a phenylene group having a fluorine atom. Etc. An alkylene group having a fluorine atom is more preferable, and a preferable carbon number is 2 to 6, more preferably 2 to 4. The alkylene chain may have a linking group such as an oxygen atom or a sulfur atom. The alkylene group is preferably an alkylene group in which 30 to 100% of the number of hydrogen atoms are substituted with fluorine atoms, more preferably a perfluoroalkylene group, and particularly preferably a perfluoroethylene group, a perfluoropropylene group, or a perfluorobutylene group. .

  The monovalent organic group in Qx is preferably an organic group having 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. Examples of the alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group are the same as those described above.

In the general formula (A-III), X ₁ , X ₂ and X ₃ are preferably —SO ₂ —.

  Hereinafter, although the specific example of a compound represented by general formula (A-II) is shown, this invention is not limited to this.

  As the compound (A), a sulfonium salt compound of the compound represented by the general formula (AI), (A-II) or (A-III), the general formula (AI), (A-II) or The iodonium salt compound of the compound represented by (A-III) is preferable, and the compound represented by the following general formula (A1) or (A2) is more preferable.

In general formula (A1),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a sulfonate anion or carboxylate anion from which a hydrogen atom of the —SO ₃ H site or —COOH site of the compound represented by the general formula (AI) is removed, or a general formula (A-II) or (A -III) represents an anion of the compound represented by

The carbon number of the organic group in R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
It is also possible to form the two members ring structure of the R ₂₀₁ to R _203, 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).
Specific examples of the organic group for R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (A1a), (A1b) and (A1c) described later.
In addition, the compound which has two or more structures represented by general formula (A1) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (A1) is at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (A1) It may be a compound.

  More preferred components (A1) include compounds (A1a), (A1b), and (A1c) described below.

Compound (A1a) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (A1), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.
Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, diarylcycloalkylsulfonium compounds, aryldialkylsulfonium compounds, aryldicycloalkylsulfonium compounds, arylalkylcycloalkylsulfonium compounds, and the like.
The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.
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 hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, most preferably They are a C1-C4 alkyl group and a C1-C4 alkoxy group. The substituent may be substituted on any one of three R ₂₀₁ to R _203, or may be substituted on 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 (A1b) will be described.
The compound (A1b) is a compound in which R _{201 to} R ₂₀₃ in the general formula (A1) each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring having a hetero atom.
The organic group not having an aromatic ring in R ₂₀₁ to R _203, generally from 1 to 30 carbon atoms, preferably an organic group having 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, An alkoxycarbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.
The alkyl group in R _{201 to} R ₂₀₃ may be linear or branched, and is preferably a linear or branched alkyl group having 1 to 20 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ is a straight-chain or branched 2-oxoalkyl group, an alkoxycarbonylmethyl group are preferred.
Preferred examples of the cycloalkyl group for R _{201 to} R ₂₀₃ include cycloalkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is a 2-oxocycloalkyl group is more preferable.
The linear or branched 2-oxoalkyl group in R _{201 to} R ₂₀₃ may have a double bond in the chain, and preferably has> C═O at the 2-position of the alkyl group. The group can be mentioned.
The 2-oxocycloalkyl group in R _{201 to} R ₂₀₃ may have a double bond in the chain, and preferably includes a group having> C═O at the 2-position of the cycloalkyl group. be able to.
The alkoxy group in the alkoxycarbonylmethyl group of R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), an alkoxycarbonyl group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group. .

  The compound (A1c) is a compound represented by the following general formula (A1c), and is a compound having an arylacylsulfonium salt structure.

In general formula (A1c):
_R213 represents an aryl group which may have a substituent, and is preferably a phenyl group or a naphthyl group. Preferred substituents in R _213, an alkyl group, an alkoxy group, an acyl group, a nitro group, a hydroxyl group, an alkoxycarbonyl group and a carboxy group.
R ₂₁₄ and R ₂₁₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Y ₂₀₁ and Y ₂₀₂ each independently represents an alkyl group, a cycloalkyl group, an aryl group, or a vinyl group.
X ⁻ represents a sulfonate anion or carboxylate anion from which a hydrogen atom of the —SO ₃ H site or —COOH site of the compound represented by the general formula (AI) is removed, or a general formula (A-II) or (A -III) represents an anion of the compound represented by
R ₂₁₃ and R ₂₁₄ may be bonded to form a ring structure, R ₂₁₄ and R ₂₁₅ may be bonded to form a ring structure, and Y ₂₀₁ and Y ₂₀₂ are bonded to each other. To form a ring structure. These ring structures may contain an oxygen atom, a sulfur atom, an ester bond, or an amide bond. Examples of the group R ₂₁₃ and R _214, R ₂₁₄ and R _215, Y ₂₀₁ and Y ₂₀₂ are formed by combined include a butylene group and a pentylene group.

As the alkyl group for R ₂₁₄ , R ₂₁₅ , Y _201, and Y ₂₀₂ , a linear or branched alkyl group having 1 to 20 carbon atoms is preferable. Examples of the alkyl group for Y ₂₀₁ and Y ₂₀₂ include a 2-oxoalkyl group having> C═O at the 2-position of the alkyl group, an alkoxycarbonylalkyl group (preferably an alkoxy group having 2 to 20 carbon atoms), and a carboxyalkyl group. More preferred.
The cycloalkyl group for R ₂₁₄ , R ₂₁₅ , Y ₂₀₁ and Y ₂₀₂ is preferably a cycloalkyl group having 3 to 20 carbon atoms.

Y ₂₀₁ and Y ₂₀₂ are preferably an alkyl group having 4 or more carbon atoms, more preferably an alkyl group having 4 to 6, and further preferably 4 to 12.
In addition, at least one of R ₂₁₄ or R ₂₁₅ is preferably an alkyl group, and more preferably both R ₂₁₄ and R ₂₁₅ are alkyl groups.

In the general formula (A2),
_R204 and _R205 each independently represents an aryl group, an alkyl group or a cycloalkyl group.
X ⁻ represents a sulfonate anion or carboxylate anion from which a hydrogen atom of the —SO ₃ H site or —COOH site of the compound represented by the general formula (AI) is removed, or a general formula (A-II) or (A -III) represents an anion of the compound represented by

The aryl group of R ₂₀₄ and R _205, a phenyl group, a naphthyl group, more preferably a phenyl group.
The alkyl group in R ₂₀₄ and R ₂₀₅ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group).
Preferred examples of the cycloalkyl group for R ₂₀₄ and R ₂₀₅ include cycloalkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group).
_R204 and _R205 may have a substituent. Examples of the substituent that R204 and R205 may have include, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), and an aryl group (for example, 6 to 15 carbon atoms). , Alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups, and the like.

  The compound that generates the compound represented by the general formula (AI), (A-II), or (A-III) upon irradiation with actinic rays or radiation is preferably represented by the general formula (A1). A compound, more preferably compounds (A1a) to (A1c).

Compound (A) decomposes upon irradiation with actinic rays or radiation to generate, for example, a compound represented by general formula (A-1) or (A-2).
The compound represented by the general formula (A-1) has a sulfo group or a carboxyl group together with a proton acceptor functional group, so that the proton acceptor property decreases or disappears compared to the compound (A), or the proton acceptor. It is a compound that has changed from scepter to acidic.
The compound represented by the general formula (A-2) has an organic sulfonylimino group or an organic carbonylimino group together with a proton acceptor functional group, so that the proton acceptor property decreases and disappears compared to the compound (A). Or a compound that is changed from proton acceptor property to acidity.
In the present invention, the acceptor property is lowered when the non-covalent complex which is a proton adduct is formed from a compound having a proton acceptor functional group and a proton, and the equilibrium constant in the chemical equilibrium is reduced. Means.
Proton acceptor property can be confirmed by measuring pH.

  Hereinafter, although the specific example of the compound (A) which generate | occur | produces the compound represented by general formula (AI) by irradiation of actinic light or a radiation is given, this invention is not limited to this.

  These compounds are synthesized from a compound represented by the general formula (AI) or a lithium, sodium or potassium salt thereof and a hydroxide, bromide or chloride of iodonium or sulfonium, etc. Or a salt exchange method described in JP-A No. 2003-246786.

Hereinafter, although the specific example of the compound (A) which generate | occur | produces the compound represented by general formula (A-II) by irradiation of actinic light or a radiation is given, this invention is not limited to this.

These compounds can be easily synthesized by using a general sulfonic acid esterification reaction or sulfonamidation reaction. For example, one sulfonyl halide part of a bissulfonyl halide compound is selectively reacted with an amine or alcohol containing a partial structure represented by the general formula (A-II) to form a sulfonamide bond or a sulfonate bond Then, the other sulfonyl halide moiety can be hydrolyzed, or the cyclic sulfonic acid anhydride can be opened with an amine or alcohol containing a partial structure represented by the general formula (A-II). . An amine or alcohol containing a partial structure represented by the general formula (A-II) is an amine, an alcohol such as (R′O ₂ C) ₂ O or an anhydride such as R′O ₂ CCl, acid It can be synthesized by reacting with a chloride compound.

  The content of the compound (A) in the positive resist composition of the present invention is preferably from 0.1 to 20 mass%, more preferably from 0.1 to 10 mass%, based on the solid content of the composition.

Basic Compound The positive resist composition of the present invention preferably contains a basic compound in order to reduce the change in performance over time from exposure to heating.
Preferable structures include structures represented by the following formulas (A) to (E).

In formulas (A) to (E), R ²⁵⁰ , R ²⁵¹ and R ²⁵² each independently represent a hydrogen atom, a carbon number of 1 to
20 alkyl groups, cycloalkyl groups having 3 to 20 carbon atoms, or aryl groups having 6 to 20 carbon atoms, wherein R ²⁵⁰ and R ²⁵¹ may be bonded to each other to form a ring. Examples of the alkyl group and cycloalkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, an aminocycloalkyl group having 3 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, and a 3 to 20 carbon atom. A hydroxycycloalkyl group is preferred.
These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.
R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represent an alkyl group or cycloalkyl group having 1 to 20 carbon atoms.

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

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

  These basic compounds are used alone or in combination of two or more. The usage-amount of a basic compound is 0.001-10 mass% normally on the basis of solid content of a positive resist composition, Preferably it is 0.01-5 mass%. In order to obtain a sufficient addition effect, 0.001% by mass or more is preferable, and 10% by mass or less is preferable in terms of sensitivity and developability of the non-exposed area.

Fluorine-based and / or silicon-based surfactant The positive resist composition of the present invention further comprises a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant and silicon-based surfactant, fluorine atom and silicon atom It is preferable to contain either one or two or more surfactants containing both.
When the positive resist composition of the present invention contains the above-described surfactant, a resist pattern with good adhesion and low development defects can be obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It becomes possible.

As these surfactants, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540 No. 7, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A 2002-277862, US Pat. No. 5,405,720. , No. 5,360,692, No. 5,529,881, No. 5,296,330, No. 5,543,098, No. 5,576,143, No. 5,294,511, No. 5,824,451. The following commercially available surfactants can also be used as they are.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). 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 (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

  The amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the positive resist composition (excluding the solvent).

Acetal Compound The positive resist composition of the present invention preferably further contains an acetal compound represented by the following general formula (A) and / or an acetal compound represented by the general formula (B).

In general formulas (A) and (B),
R ₁ ′ and R ₂ ′ each independently represents an organic group.

In the general formulas (A) and (B), R ₁ ′ and R ₂ ′ are preferably organic groups having 1 to 30 carbon atoms, more preferably alkyl groups, cycloalkyl groups, and alkenyl groups. , An aralkyl group and an aryl group, more preferably an alkyl group, a cycloalkyl group and an aryl group.

  The acetal compound is a compound in which the acetal is decomposed by the action of an acid and the solubility in an alkaline developer is increased.

  Hereinafter, although the specific example of an acetal compound is given, this invention is not limited to this.

  The acetal compound may be a polymer (resin) having an acetal structure. The polymer having an acetal structure may have an acetal structure in the main chain or side chain of the resin, or in both the main chain and the side chain. Among these, a polymer having an acetal structure in the side chain is more preferable.

  Hereinafter, although the specific example of the polymer which has an acetal structure is given, this invention is not limited to this.

  The addition amount of the acetal compound in the positive resist composition of the present invention is preferably 0.001 to 60% by mass, more preferably 0.01 to 40% by mass with respect to the total mass of the total solid content of the composition. Especially preferably, it is 0.1-20 mass%. Moreover, 1 type may be used for an acetal compound, and 2 or more types may be used for it.

Solvent The positive resist composition of the present invention is dissolved in a solvent that dissolves the above-described components and the components described later, and is applied onto a support. Solvents used here include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate , Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethyl Formamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable. These organic solvents can be used individually by 1 type or in combination of 2 or more types.

  Among these, preferable organic solvents include 2-heptanone, γ-butyrolactone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl. Examples include ether acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, N-methylpyrrolidone, and tetrahydrofuran.

  Among the above, it is more preferable to contain propylene glycol monomethyl ether acetate as a solvent. In addition to propylene glycol monomethyl ether acetate, it is preferable to further contain propylene glycol monomethyl ether in view of line edge roughness and performance change reduction by PED in vacuum.

Pattern Forming Method After applying the positive resist composition according to the present invention on a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit device by an appropriate coating method such as a spinner or a coater. A good resist pattern can be obtained by drying or pre-baking to form a resist film, exposing through a predetermined mask, preferably post-baking, and developing. An antireflection film may be provided on the substrate in advance.
Here, as the exposure light, for example, far ultraviolet light having a wavelength of 250 nm or less, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), EUV (13 nm), X And KrF excimer laser, electron beam, X-ray and EUV are particularly preferable.

  In the pattern formation by the positive resist composition of the present invention, as an alkaline developer used for development, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, Primary amines such as ethylamine and n-propylamine, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine Alkaline aqueous solutions such as quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide, and cyclic amines such as pyrrole and pihelidine can be used.

Furthermore, an appropriate amount of alcohol or surfactant may be added to the alkaline aqueous solution.
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.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example. In addition, Examples 1-3, 5, 14, 16-23, 25, 34-40, 42-47, 49, and 50 shall be read as a reference example.

[Synthesis example regarding polymer of component (A)]
Synthesis Example 1 Synthesis of Macromonomer 1

In a reaction vessel, 76.9 g (0.4 mol) of p- (1-ethoxyethyl) styrene (manufactured by Tosoh Corporation) and 76.9 g (0.6 mol) of t-butyl acrylate were dissolved in 250 ml of tetrahydrofuran, and the system was stirred. Nitrogen gas was allowed to flow through. Thereto were added 18.42 g (0.2 mol) of 3-mercaptoacetic acid and 12.42 g (0.05 mol) of a polymerization initiator V-65 (manufactured by Wako Pure Chemical Industries), and the reaction solution was heated to 60 ° C. After stirring with heating for 10 hours, the reaction solution was allowed to cool to room temperature and dropped into 3 L of distilled water to precipitate the polymer. The filtered solid was dissolved in 150 ml of acetone, dropped again into 3 L of distilled water, and the filtered solid was dried under reduced pressure to obtain 135.3 g of an intermediate.
100 g of the intermediate obtained above, 9.41 g of triethylamine, 8.94 g of glycidyl acrylate, 0.1 g of hydroquinone and 200 ml of methyl ethyl ketone were added to the reaction vessel, heated to 60 ° C. and stirred for 2 hours. The reaction solution was allowed to cool to room temperature and dropped into 3 L of distilled water. The filtered solid was dissolved in 150 ml of acetone, dropped again into 3 L of distilled water, and the filtered solid was dried under reduced pressure to obtain 120.3 g of macromonomer 1. The weight average molecular weight by GPC / MALLS (multi-angle light scattering) was 4300. From the 1H-NMR analysis, it was found that the ratio of p- (1-ethoxyethyl) styrene / t-butyl acrylate was 43/57, and the double bond abundance ratio was 0.215 mmol / g. Therefore, the above-described n _b (average polymerization degree of the portion to be a branched chain) is 27.6.

(Synthesis Example 2) Synthesis of polymer PA1

2.98 g of p- (1-ethoxyethyl) styrene (manufactured by Tosoh) in a reaction vessel (0.01
6 mol), 2.63 g (0.021 mol) of t-butyl acrylate and 65.12 g of macromonomer 1 (average double bond mole number 0.014 mol) were dissolved in 150 ml of tetrahydrofuran, and nitrogen gas was introduced into the system while stirring. Washed away. 0.89 g (0.0036 mol) of polymerization initiator V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto, and the reaction solution was heated to 60 ° C. After stirring with heating for 10 hours, the reaction solution was allowed to cool to room temperature and dropped into 3 L of distilled water to precipitate the polymer. The filtered solid was dissolved in 150 ml of acetone, dropped again into 3 L of distilled water and filtered to obtain a solid. This solid was added to a reaction vessel, 200 ml of methanol, 20 ml of distilled water and 1.0 g of p-toluenesulfonic acid were added, heated to 60 ° C. and stirred for 3 hours. Thereafter, the reaction solution was dropped into 3 L of distilled water, the filtered solid was dissolved in 150 ml of acetone, and the filtered solid was dropped again into 3 L of distilled water and dried under reduced pressure to obtain 38.4 g of a polymer. Thereafter, this polymer was dissolved in PGMEA to obtain a 30% by mass solution. This polymer is designated as PA1. The weight average molecular weight by GPC / MALLS was 32000. From 1H-NMR analysis, the ratio of p-hydroxystyrene / t-butyl acrylate / macromonomer 1 was 31/41/28, and the overall ratio of p-hydroxystyrene / t-butyl acrylate was 41/59. Therefore, the above-mentioned n _m (average degree of polymerization of the main portion (main chain)) is 38.0, and x (average number of branch points in one polymer molecule) is 10.6.

Synthesis Example 3 Synthesis of Multifunctional Initiator 1

In a reaction vessel, 73.10 g (0.2 mol) of 2,2-6,6-tetramethyl-1- (2-hydroxy-1-phenylethoxy) -piperidine and ml of tetrahydrofuran were added, and nitrogen was added to the system while stirring. Gas was flowed and the solution was cooled to -40 ° C. Thereto was added 4.8 g (0.2 mol) of sodium hydride, and the mixture was further stirred for 20 minutes. Thereafter, 20.24 g (0.045 mol) of 1,2,4,5-tetrakis (bromomethyl) benzene was added, and the reaction solution was gradually warmed to room temperature. Thereafter, a saturated aqueous ammonium chloride solution was added to stop and neutralize the reaction, and extraction was performed with 300 ml of ethyl acetate and 100 ml of distilled water. Magnesium sulfate was added to the ethyl acetate layer for dehydration, the solvent was distilled off, and the residue was purified by silica gel column chromatography to obtain 185.3 g of polyfunctional initiator 1.
The 2,2-6,6-tetramethyl-1- (2-hydroxy-1-phenylethoxy) -piperidine described above is journaled except that the raw material is changed from styrene to p- (1-ethoxyethyl) styrene. of American Chemical Society 1994, Vol. 116, p.11185.

  The structure of 2,2-6,6-tetramethyl-1- (2-hydroxy-1-phenylethoxy) -piperidine is as follows:

(Synthesis Example 4) Synthesis of polymer PA2

3.18 g (0.002 mol) of polyfunctional initiator 1 and 38.45 g (0.2 mol) of p- (1-ethoxyethyl) styrene (manufactured by Tosoh) were added to the reaction vessel, and the system was stirred. Nitrogen gas was flowed and the reaction solution was heated to 130 ° C. After 10 hours of heating and stirring, the reaction solution was allowed to cool to room temperature. Further, 100 ml of ethyl acetate, 20 ml of methanol, 5 ml of distilled water and 0.5 g of p-toluenesulfonic acid were added, and the reaction solution was heated to 60 ° C. and stirred for 2 hours. Thereafter, the reaction solution was dropped into 2 L of distilled water to precipitate the polymer. The filtered solid was dissolved in 100 ml of acetone, dropped again into 2 L of distilled water, filtered, and dried under reduced pressure to obtain 23.7 g of a powder. 65.1 g of this powder was dissolved in 300 g of PGMEA, this solution was depressurized to 60 mm and 20 mmHg, and about 60 g of the solvent was distilled off together with water remaining in the system. After cooling to 20 ° C., 16.03 g of 2-cyclohexaneethanol, 12.52 g of t-butoxyvinyl ether and 0.5 g of p-toluenesulfonic acid pyridinium salt were added, and the mixture was stirred at room temperature for 4 hours. Thereafter, 0.4 g of triethylamine was added for neutralization, 100 g of ethyl acetate, 10
The washing operation was performed 3 times with 0 g. Thereafter, the amount of the solvent was adjusted to obtain a 30% by mass polymer solution. This polymer is designated as PA2. The weight average molecular weight measured by GPC / MALLS (multi-angle light scattering) was 18000, 1H and 13C-NMR analysis showed that the acetal protection rate of phenolic OH was 14.5%. Therefore, y (average of the number of branched chains (branches) extending from the core portion) is 4, n _h (average degree of polymerization of each branched chain) is 31.3, and the molecular weight of the core portion is 194.

Synthesis Example 5 Synthesis of Intermediate 1

  In a reaction vessel, 203.0 g (1.0 mol) of 5-bromo-2-hydroxybenzyl alcohol was dissolved in 500 ml of carbon tetrachloride, and 314.75 g (1.2 mol) of triphenylphosphine was added, followed by heating under reflux for a period of time. It was. The reaction solution was allowed to cool to room temperature, and then washed and separated using a saturated aqueous sodium hydrogen carbonate solution and distilled water. Magnesium sulfate was added to the organic layer for dehydration, the solvent was distilled off, and purification was performed by silica gel column chromatography to obtain 197.6 g of Intermediate 1.

Synthesis Example 6 Synthesis of Intermediate 2

  177.18 g (0.8 mol) of Intermediate 1 obtained in Synthesis Example 5 and 200 ml of pyridine were added to the reaction vessel, and 163.34 g (1.6 mol) of acetic anhydride was added dropwise over 1 hour. After the dropwise addition, the mixture was further stirred for 2 hours, further added with 500 ml of ethyl acetate, washed twice with a 0.1N HCl aqueous solution, and the organic layer was further washed with a saturated aqueous sodium bicarbonate solution and distilled water and separated. Magnesium sulfate was added to the organic layer for dehydration, the solvent was distilled off, and purification was performed by silica gel column chromatography to obtain 202.38 g of Intermediate 2.

Synthesis Example 7 Synthesis of Monomer 1

In a reaction vessel, 131.76 g (0.5 mol) of Intermediate 2 obtained in Synthesis Example 6 was dissolved in 250 ml of dehydrated tetrahydrofuran, and the system was purged with nitrogen. 5 mol% and 10 mol% of nickel (II) chloride and triphenylphosphine were added to the intermediate 2 and stirred, and 500 ml of vinylmagnesium bromide (1.0 M tetrahydrofuran solution) was added and heated to 60 ° C. Stir for 4 hours. After returning to room temperature, washing with ethyl acetate-water,
Extraction was performed. The organic layer was dehydrated with anhydrous sodium sulfate g and the solvent was distilled off. Then, the product was purified by silica gel chromatography to obtain 84.26 g of monomer 1.

(Synthesis Example 8) Synthesis of polymer PA3

In a reaction vessel, 42.13 g (0.2 mol) of monomer 1 obtained in Synthesis Example 7 was dissolved in 100 ml of chlorobenzene, and nitrogen gas was allowed to flow through the system while stirring. Thereto, 0.2 equivalent and 0.1 equivalent of 2,2′-bipyridyl and CuCl were added to monomer 1, respectively, heated to 115 ° C. and stirred for 4 hours. The reaction solution was allowed to cool to room temperature, 100 ml of tetrahydrofuran was added, and the mixture was further stirred for 2 hours. Thereafter, the reaction solution was filtered through alumina, and the filtrate was dropped into 3 L of methanol to precipitate a polymer. The filtered solid was acetone 100
It was dissolved in ml, dropped again into 3 L of methanol, filtered, and dried under reduced pressure to obtain 27.81 g of powder. This powder was added to the reaction vessel, and further 100 ml of methanol and 0.91 g (0.01 mol) of tetramethylammonium hydroxide were added, followed by heating under reflux for 3 hours. Thereafter, 1N-HCl aqueous solution was added for neutralization, and the resulting solution was dropped into 2 L of distilled water to precipitate the polymer. The filtered solid was dissolved in 50 ml of acetone, dropped again in 2 L of distilled water, filtered, and dried under reduced pressure to obtain 19.37 g of powder. This powder was dissolved in 100 g of PGMEA, this solution was decompressed to 60 mm and 20 mmHg, and about 20 g of the solvent was distilled off with water remaining in the system.
The mixture was cooled to 20 ° C., 3.77 g of 2-phenoxyethyl vinyl ether and 1.0 g of p-toluenesulfonic acid were added, and the mixture was stirred at room temperature for 1 hour. Thereafter, 1.16 g of triethylamine was added for neutralization, and the washing operation was performed 3 times with 40 g of ethyl acetate and 40 g of water. Thereafter, the amount of the solvent was adjusted to obtain a 30% by mass polymer solution. This polymer is designated as PA3. The weight average molecular weight measured by GPC / MALLS (multi-angle light scattering) was 26000. From 1H and 13C-NMR analysis, the average molar ratio of the repeating unit having a branch point and the repeating unit having no branch point in one molecule of the polymer was 76:24. Moreover, the acetal protection rate of phenolic OH was 21.5%.

(Synthesis Example 9) Synthesis of Polymer PA4 Polymer PA4 having the following structure was synthesized in the same manner except that vinyl ether in Synthesis Example 4 was changed. The weight average molecular weight was 15000, and the protection ratio of phenolic hydroxyl group was 37.6%. y = 4, n _h = 25.5, and the molecular weight of the core part was 194.

(Synthesis Example 10) Synthesis of linear polymers T-1 to T-4 and K Using the existing method, the polymers PA1 to PA4 of the present invention have the same monomer composition and weight average molecular weight, The chain polymers T-1 to T-4 were synthesized to obtain a 30% by mass PGMEA solution.
T-4: Weight average molecular weight 15000, protection ratio of phenolic hydroxyl group: 37.5%

(Confirmation of branching degree)
Table 1 shows the weight average molecular weight (Mw) of the polymers PA1 to PA4 and T-1 to T-4 as measured by GPC / MALLS (multi-angle light scattering) and the value of α ₁ / α _x . Where α _x , α _l
Is obtained by the following definition.
α _x : slope determined by least square method from plot of <R ₂ > ^1/2 (square root of root mean square of radius R) and logarithm of Mw determined from GPC / MALLS of polymers PA1 to PA4 of the present invention α _l : Inclination obtained in the same manner as α _x above for linear polymers T-1 to T-4 corresponding to PA1 to PA4, respectively.

From the results in Table 2, it can be seen that the polymers PA1 to PA4 of the present invention all have (α ₁ / α _x )> 1, and a branched chain exists in the polymer.

[Synthesis Example of Compound of Component (B)]
Synthesis example 1
10 g of 4,4′-thiodiphenol was stirred in 40 ml of trifluoroacetic acid, and a solution prepared by mixing 5.4 ml of 30% hydrogen peroxide and 10.8 ml of trifluoroacetic acid was slowly added under ice cooling. Thereafter, the mixture was stirred for 30 minutes under ice cooling, and then stirred at room temperature for 1 hour. Further, the reaction solution was poured into water, and the precipitated crystals were collected by filtration. The obtained crystals were recrystallized from acetonitrile to obtain 4.6 g of a sulfoxide form.
3 g of the sulfoxide compound was stirred in 20 ml of toluene, and 3.7 ml of trifluoroacetic anhydride and 2.2 ml of nonafluorobutanesulfonic acid were added under ice cooling. The reaction was gradually warmed to room temperature and stirred for 1 hour. Diisopropyl ether was added to the reaction solution to precipitate crystals, and recrystallized with a mixed solvent of ethyl acetate and diisopropyl ether to obtain 3.9 g of tri (4-hydroxyphenyl) sulfonium nonafluorobutanesulfonate (B1). .
Other compounds can be synthesized similarly.

[Synthesis Example of Compound (A)]
Synthesis Example 1 (Synthesis of Compound (A-1))
Place 1,1,2,2,3,3-Hexafluoro-propane-1,3-disulfonyl difluoride 15.0 g (47.4 mmol) in a 500 mL three-necked flask equipped with a 300 mL dropping funnel and a nitrogen inlet tube, and add 150 mL of THF under nitrogen. The mixture was dissolved in ice and stirred with ice cooling, and 100 mL of a THF solution of 7.98 g (47.4 mmol) of 4-piperidinopiperidine and 9.60 g (47.4 mmol) of triethylamine was added dropwise from a dropping funnel over 1 hour. After dropping, the mixture was stirred for 1 hour under ice-cooling, and the ice bath was further removed, followed by stirring at room temperature for 4 hours. 200 ml of AcOEt and 100 ml of water were added to the reaction solution, and the precipitated solid was filtered and washed with acetone to obtain 13.1 g of a white solid having the following structure. 11.1 g of this solid was stirred in a mixed solvent of 300 mL of MeOH and 50 mL of 1M aqueous sodium hydroxide solution at room temperature for 1 hour. To this was added 8.2 g (24 mmol) of triphenylsulfonium bromide, and the mixture was stirred at room temperature for 3 hours. Chloroform 200 mL was added, the organic layer was washed several times with water, the organic layer was concentrated and vacuum dried to obtain 14.2 g of the target solid.
¹ H-NMR (300 MHz, CDCl3) δ 1.43 (m, 2H), 1.58 (m, 6H), 1.70 (m, 2H), 2.41 (t, 1H), 2.48 (m, 4H), 3.05 (t, 2H), 4.01 (d, 2H), 7.72 (m, 15H)
¹⁹ F-NMR (300 MHz, CDCl3) δ-114.4 (t, 2F), -118.0 (m, 2F), -122.9 (m, 2F)

Synthesis Example 2 (Synthesis of Compound (A-33))
Place 1,1,2,2,3,3-Hexafluoro-propane-1,3-disulfonyl difluoride 15.0 g (47.4 mmol) in a 500 mL three-necked flask equipped with a 300 mL dropping funnel and a nitrogen inlet tube, and add 150 mL of THF under nitrogen. Then, the mixture was stirred in an ice bath, and 100 mL of a THF solution of 4.75 g (47.4 mmol) of 4-methylpiperazine and 4.80 g (47.4 mmol) of triethylamine was added dropwise from a dropping funnel over 1 hour. After dropping, the mixture was stirred for 1 hour under ice-cooling, and the ice bath was further removed, followed by stirring at room temperature for 4 hours. To the reaction solution was added 50 mL of 1M aqueous sodium hydroxide solution, and the mixture was stirred at room temperature for 4 hours. Thereafter, 14.6 g (43 mmol) of triphenylsulfonium bromide was added thereto, and the mixture was stirred at room temperature for 3 hours. 300 mL of chloroform was added, the organic layer was washed several times with water, and the organic layer was concentrated and vacuum dried to obtain 14.9 g of the target solid.

¹ H-NMR (400 MHz, CDCl3) δ 2.31 (s, 3H), 2.45 (bs, 4H), 3.56 (bs, 4H), 7.72 (m, 15H)
¹⁹ F-NMR (400 MHz, CDCl3) δ-110.8 (t, 2F), -114.0 (m, 2F), -119.0 (t, 2F)

Synthesis Example 3 (Synthesis of Compound (A-39))
Triphenylsulfonium bromide 16.1 g (46.9 mmol) and silver oxide 12.4 g (53.5 mmol)
Was added to 150 mL of methanol and stirred at room temperature for 2 hours. The silver salt is removed by filtration and the filtrate is N
N-bis (2-hydroxyethyl) -2-aminoethanesulfonic acid 10.0 g (46.9 mmol) was added, and the mixture was further stirred for 1 hour. The solvent was removed and dried to obtain 22.5 g of the desired white solid.
¹ H-NMR (400 MHz, CDCl3) δ 2.615 (m, 4H), 3.005 (s, 4H), 3.583 (bs, 4H), 4.932 (bs, 2H), 7.277-7.835 (m, 15H)

Synthesis Example 4 (Synthesis of Compound (A-40))
Triphenylsulfonium bromide 16.1 g (46.9 mmol) and silver oxide 12.4 g (53.5 mmol)
Was added to 150 mL of methanol and stirred at room temperature for 2 hours. The silver salt is removed by filtration and 2% is added to the filtrate.
10.57 g (46.9 mmol) of -hydroxy-3-morpholinopropanesulfonic acid was added, and the mixture was further stirred for 1 hour. The solvent was removed and dried to obtain 20.0 g of the desired colorless oil.
¹ H-NMR (400 MHz, CDCl3) δ 2.354 (m, 1H), 2.543 (m, 5H), 2.842 (m, 1H), 3.084 (m, 1H), 3.694 (t, 4H), 4.35 (m, 1H), 5.02 (bs, 1H), 7.684-7.823 (m, 15H)

Synthesis Example 5 (Synthesis of Compound (A-42))
Triphenylsulfonium bromide 16.1 g (46.9 mmol) and silver oxide 12.4 g (53.5 mmol)
Was added to 150 mL of methanol and stirred at room temperature for 2 hours. The silver salt is removed by filtration and the filtrate is N
-Cyclohexyl-3-aminopropanesulfonic acid 10.38 g (46.9 mmol) was added, and the mixture was further stirred for 1 hour. The solvent was removed and dried to obtain 24.8 g of the desired colorless oil.
¹ H-NMR (400 MHz, CDCl3) δ 0.98-1.28 (m, 6H), 1.61 (d, 1H), 1.69 (d, 2H), 1.85 (d, 2H), 2.42 (m, 1H), 2.73 ( t, 2H), 2.88 (m, 2H), 7.72 (m, 9H), 7.85 (m, 6H)

Synthesis Example 6 (Synthesis of Compound (A-59))
Add 34.4 g (200 mmol) of sulfanilamide to a 1000 mL three-necked flask equipped with a 100 mL dropping funnel and a nitrogen inlet tube, dissolve in 200 mL of 10% -NaOH, stir with ice cooling, and add 55.3 g of 1-octanesulfonyl chloride from the dropping funnel. 200 mmol) was added dropwise over 1 hour. After dropping, the mixture was stirred for 1 hour under ice cooling, and the ice bath was further removed, followed by stirring at room temperature for 3 hours. Concentrated hydrochloric acid was added dropwise to the reaction solution to neutralize it, and the precipitated white solid was filtered. This solid was recrystallized from water / methanol to obtain 45.1 g of the following compound as plate-like crystals.

Triphenylsulfonium bromide 16.1 g (46.9 mmol) and silver oxide 12.4 g (53.5 mmol)
Was added to 150 mL of methanol and stirred at room temperature for 2 hours. The silver salt was removed by filtration, 16.34 g (46.9 mmol) of the above compound was added to the filtrate, and the mixture was further stirred for 1 hour. After removing the solvent, 200 mL of chloroform was added and the organic layer was washed with water. The solvent was removed and dried to obtain 20.9 g of white solid compound (A-59).
¹ H-NMR (400 MHz, CD3OD) δ 0.93 (t, 3H), 1.34-1.46 (m, 10H), 1.81 (quin, 2H), 3.24 (t, 2H), 6.78 (d, 2H), 7.66- 7.78 (m, 17H)

Synthesis Example 7 (Synthesis of Compound (A-64))
8.01 g (23.34 mmol) of triphenylsulfonium bromide and 5.68 g (24.51 mmol) of silver oxide were added to 100 mL of methanol and stirred at room temperature for 2 hours. The silver salt was removed by filtration, and 5.0 g (23.34 mmol) of sulfaacetamide was added to the filtrate, followed by further stirring for 1 hour. The solvent was removed and dried to obtain 10.0 g of white solid compound (A-64).
¹ H-NMR (400 MHz, CD3OD) δ 1.84 (s, 3H), 6.63 (d, 2H), 7.63 (d, 2H), 7.78-7.87 (m, 15H)

Synthesis Example 8 (Synthesis of Compound (A-66))
Under a nitrogen stream, a mixture of 5.0 g (15.8 mmol) of 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonyldifluoride and 50 mL of THF was ice-cooled, and 1-methylpiperazine 1.66 was added thereto. A mixed solution of g (16.6 mmol), 10 mL of triethylamine and 50 mL of THF was added dropwise over 60 minutes. The mixture was stirred for 1 hour under ice cooling, and further stirred at room temperature for 1 hour. The organic layer was washed successively with water, a saturated aqueous ammonium chloride solution and water, and the organic layer was dried over sodium sulfate. The solvent was concentrated, 2.36 g (15.8 mmol) of trifluoromethanesulfonamide and 10 mL of triethylamine were added to the residue, transferred to a pressure-resistant glass tube, and stirred at 100 ° C. for 20 hours in a sealed tube. 100 mL of chloroform was added, the organic layer was washed with water, and the organic layer was dried over sodium sulfate to obtain a brown oil. Methanol 25mL and 1.5N-HCl 60mL were made neutral to this, and the depositing white solid was filtered, and the following compound 5.65g was obtained.

4.0 g of the above compound was dissolved in a mixed solvent of 100 mL of methanol and 40 mL of 1M NaOH, and 2.61 g (7.61 mmol) of triphenylsulfonium bromide was added and stirred at room temperature for 3 hours. Chloroform 20
0 mL was added, the organic layer was washed with water, the solvent was removed, and the residue was purified by column chromatography (SiO2, chloroform / methanol = 10/1) to obtain the target compound (A-66) (4.56 g) as a white solid. It was.
¹ H-NMR (400 MHz, CDCl3) δ 2.32 (s, 3H), 2.50 (m, 4H), 3.55 (m, 4H), 7.65-7.80 (m, 15H)
¹⁹ F-NMR (400 MHz, CDCl3) δ -118.5 (m, 2F), -112.3 (m, 2F), -111.1 (m, 2F), -78.6 (m 3F)

Examples 1-36 and Comparative Examples 1-7
Preparation, pattern formation and evaluation of positive resist Resins, acid generators, proton acceptor-containing compounds, surfactants and basic compounds shown in Tables 3 to 4 below are dissolved in propylene glycol monomethyl ether acetate, and the solid content concentration After preparing a 5.0 mass% solution, the obtained solution was microfiltered with a membrane filter having a 0.1 μm aperture to obtain a resist solution.

The obtained resist solution was applied onto a 6-inch silicon wafer using a spin coater Mark8 manufactured by Tokyo Electron, and baked at 110 ° C. for 90 seconds to obtain a uniform film having a thickness of 0.25 μm.
This resist film was subjected to EUV exposure using an EUV exposure apparatus. After irradiation, it was baked at 110 ° C. for 90 seconds, immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds, and dried to form a pattern.

〔sensitivity〕
Scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.) was used for the cross-sectional shape of the obtained pattern.
Was observed. Sensitivity was defined as the minimum irradiation energy when resolving a 0.15 μm line (line: space = 1: 1).
[Resolution]
The resolving power was defined as the limiting resolving power (line and space were separated and resolving) at the irradiation dose showing the above sensitivity.
[Pattern shape]
The cross-sectional shape of the 0.15 μm line pattern at the irradiation dose showing the above sensitivity was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.), and A (rectangular), B, C (slightly tapered) , D and E (taper) were evaluated in five stages.
[Line edge roughness (LER)]
The line width was measured at any 30 points in the length direction of 50 μm of the 0.15 μm line pattern at the irradiation dose showing the above sensitivity, and the variation was evaluated by 3σ.
The said evaluation result is shown to Tables 3-4.

Pattern preparation and evaluation Using the spin coater, the resist solution prepared as described above is uniformly applied on a silicon wafer subjected to hexamethyldisilazane treatment, and is heated and dried at 120 ° C. for 90 seconds to obtain a film thickness of 0.15 μm. A positive resist film was formed. The obtained resist film was subjected to surface exposure using EUV light (wavelength 13 nm) while changing the exposure amount in steps of 0.5 mJ within a range of 0 to 10.0 mJ, and further baked at 110 ° C. for 90 seconds. Then, using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, the dissolution rate at each exposure amount was measured to obtain a sensitivity curve. In this sensitivity curve, the exposure amount when the dissolution rate of the resist is saturated was taken as sensitivity, and the dissolution contrast (γ value) was calculated from the gradient of the linear portion of the sensitivity curve. The larger the γ value, the better the dissolution contrast.

[Evaluation of film thickness fluctuation rate after exposure]
Irradiate a dose of 2.0 times the dose (mJ / cm ² ) with the sensitivity determined by performing surface exposure with EUV light, measure the film thickness after exposure (before post-heating), and use the following formula: From this, the rate of change from the unexposed film thickness was determined.
Film thickness fluctuation rate = (film thickness at unexposed-film thickness after exposure) / film thickness at unexposed

[PEB temperature dependence]
After exposure, the difference in sensitivity was evaluated as PEB temperature dependence as shown in the following equation when heated (PEB) on a hot plate at temperatures of 107 ° C. and 113 ° C. for 90 seconds. The smaller this number, the better.
(PEB temperature dependence) = (sensitivity at 113 ° C)-(sensitivity at 107 ° C)

  The said evaluation result is shown to Tables 3-4.

Abbreviations in Tables 3 to 4 are shown below.
[Basic compounds]
C-1: Tri n-octylamine C-2: 1,5-diazabicyclo [4.3.0] -5-nonene C-3: 2,4,6-triphenylimidazole [Surfactant]
W-1: Fluorosurfactant, MegaFuck F-176 (Dainippon Ink Chemical Co., Ltd.)
W-2: Fluorine / silicone surfactant, MegaFac R08 (Dainippon Ink and Chemicals)
W-3: Silicone surfactant, polysiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.)

[Comparative acid generator]
B'1: Triphenylsulfonium pentafluorobenzenesulfonate

Regarding the (B) acid generator used, when the structure is applied to the general formula (BI), Ra ~
The boiling points at 1 atm of alkanes and arenes corresponding to Rc, that is, Ra-H, Rb-H and Rc-H are also shown. Here, for convenience, Ra-H, Rb-H, and Rc-H are selected from those having a low boiling point.

  In Tables 3-4, in the usage amount of the proton acceptor group-containing compound, 0.0393 g is the usage amount when no basic compound was used in combination, and 0.0196 g represents the basic compound. The amount used when used in combination.

  From Tables 3 to 4, it can be seen that the positive resist composition of the present invention is excellent in sensitivity, resolution, LER, and pattern shape in property evaluation by irradiation with EUV light. Moreover, it turns out that it is excellent also in the point of melt | dissolution contrast, the film thickness fluctuation rate after exposure, and PEB temperature dependency. A small film thickness variation rate means that there is little outgas. Further, by including a proton acceptor group-containing compound, high sensitivity, high resolution, and low LER are obtained.

Examples 37 to 43 and Comparative Examples 8 and 9
The resist solutions of Examples 1, 2, 18, 21, 32, 35, and 36 and Comparative Examples 4 and 6 were applied onto a 6-inch silicon wafer using a spin coater Mark8 manufactured by Tokyo Electron, and baked at 110 ° C. for 90 seconds. As a result, a resist film having a thickness of 0.30 μm was obtained.
The resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750, acceleration voltage 50 KeV manufactured by Hitachi, Ltd.). After irradiation, bake at 110 ° C for 90 seconds, 2.3
After immersing in an 8% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds, it was rinsed with water for 30 seconds and dried.
The obtained pattern was evaluated for sensitivity, resolution, LER, and pattern shape in the same manner as in Example 1.
The results are shown in Table 5 below.

  From Table 5, it can be seen that the positive resist composition of the present invention has high sensitivity and high resolving power with respect to pattern formation by electron beam irradiation, and is excellent in pattern shape and line edge roughness.

Examples 44 to 50 and Comparative Examples 10 and 11
The resist solutions of Examples 1, 2, 18, 21, 32, 35, and 36 and Comparative Examples 4 and 6 were applied onto a 6-inch silicon wafer using a spin coater Mark8 manufactured by Tokyo Electron, and baked at 110 ° C. for 90 seconds. Thus, a resist film having a thickness of 0.40 μm was obtained. The obtained resist film was subjected to pattern exposure using a KrF excimer laser stepper (FPA3000EX-5 manufactured by Canon Inc., wavelength 248 nm). The post-exposure processing was performed in the same manner as in Example 1.
The obtained pattern was evaluated for sensitivity, resolution, LER, and pattern shape in the same manner as in Example 1.
The results are shown in Table 6 below.

  From Table 6, it can be seen that the positive resist composition of the present invention is higher in sensitivity and resolution than the comparative example in terms of pattern formation by KrF excimer laser exposure, and is excellent in pattern shape and line edge roughness. .

Claims (10)

(A) at least one via the branching unit having a polymer chain of three or more, the polymer over及 beauty of increasing the solubility in an alkali developing solution under action of acid (B) an actinic ray or a compound which generates an acid when exposed to radiation as a positive resist composition, characterized by containing a compound represented by the following general formula (BI).

In general formula (BI):
R ^1b , R ^2b and R ^3b each independently represents an alkyl group, a cycloalkyl group or an aryl group. However, the boiling point of the compound ^{(R 1b -H), (R} 2b -H), and (R ^3b -H) are all 1 9 0 ° C. or more (1 atm). X ⁻ represents a non-nucleophilic anion .   In the general formula (BI), R ^1b , R ^2b And R ^3b Represents an aryl group and the compound (R ^1b -H), (R ^2b -H), and (R ^3b The positive resist composition according to claim 1, wherein the boiling points of -H) are all 200 ° C or higher (1 atm). In the general formula (BI), R ^1b ~ R ^3b 3. The positive resist composition according to claim 1, wherein each of them contains 8 or less carbon atoms. 4. In addition, it contains a compound that has a proton acceptor functional group and generates a compound that decomposes upon irradiation with actinic rays or radiation to decrease, disappear, or change the proton acceptor property to acidic. The positive resist composition according to claim 1 , wherein the positive resist composition is a positive resist composition. The positive resist composition according to any one of claims 1 to 4, wherein the polymer (A) is a comb-type polymer.   The positive resist composition according to any one of claims 1 to 5, wherein at least one of the polymer chains forming the polymer (A) is composed of a vinyl-type repeating unit.   The positive resist composition according to claim 6, wherein the vinyl-type repeating unit has a repeating unit derived from a styrene derivative and / or a repeating unit derived from a (meth) acrylic acid derivative. 8. The positive resist composition according to claim 1, wherein each of R ^1b , R ^2b, and R ^3b has 8 or less carbon atoms in the general formula (BI). .   A resist film formed from the positive resist composition according to claim 1.   A pattern forming method comprising exposing and developing the resist film according to claim 9.