JP2007293249A - Positive resist composition and pattern forming method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition simultaneously satisfying high sensitivity, high resolution, excellent pattern shape and line edge roughness. <P>SOLUTION: The positive resist composition contains (Z) a compound having sulfonium cation having a structure expressed by general formula (Z-I), and (T) a low molecule compound increasing solubility to an alikali developer by action of acid. A pattern forming method using the positive resist composition is provided. In the general formula (Z-I), Y<SB>1</SB>-Y<SB>13</SB>each denote a hydrogen atom or a substitution group, and may be coupled by adjacent ones to form a ring. Z is single coupling or a bivalent coupling group. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resist composition that is suitably used in an ultramicrolithography process such as the manufacture of VLSI and high-capacity microchips and other photofabrication processes. More specifically, the present invention relates to a photoresist capable of forming a high-definition pattern using electron beam, X-ray, EUV light, etc., and preferably used for ultrafine processing of semiconductor elements using electron beam, X-ray, EUV light. 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 photoresist composition has been performed. In recent years, with the high integration of integrated circuits, the formation of ultrafine patterns in the sub-micron region and quarter-micron region has been required. Along with this trend, the exposure wavelength tends to be shortened from g-line to i-line, and further to KrF excimer laser light.

  Furthermore, in addition to excimer laser light, development of lithography using electron beams, X-rays, or EUV light is also progressing. In particular, lithography using EUV as a light source is positioned as a powerful pattern formation technology of the next generation or the next generation, and intensive research is being conducted. The required performance of the resist used includes high sensitivity, high resolution, and good line edge roughness. However, since the above performance is in a trade-off relationship, it is important how to satisfy these simultaneously. Here, line edge roughness means that when the pattern is viewed from directly above because the edge of the resist pattern and the substrate interface irregularly fluctuate 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. In particular, line edge roughness is an extremely important improvement problem in an ultrafine region of 0.25 μm or less. Such a problem is equally important in lithography using X-rays or electron beams.

  In addition to the above requirements, when a light source such as an electron beam, X-ray, or EUV is used, a resist decomposed by a low-boiling compound such as a solvent or high energy in order to perform exposure under vacuum. The problem of outgassing, in which the material volatilizes and contaminates the exposure apparatus, has also become important. In recent years, various studies have been conducted on the reduction of outgas, and a top trap layer is provided to suppress volatilization of low molecular weight compounds (see, for example, Patent Document 1) or radical traps to suppress polymer decomposition. Various attempts have been made, such as adding an agent (see, for example, Patent Document 2), but it is also desired to devise an outgas reduction method for the acid generator.

  Until now, as a resist suitable for a lithography process using electron beam, X-ray, or EUV light, a chemically amplified resist using mainly an acid-catalyzed reaction has been used from the viewpoint of high sensitivity. In a positive resist, a chemically amplified resist composition comprising a phenolic 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 and an acid generator as main components. Has been considered. However, the conventional photoresist based on a polymer compound has a problem that its molecular shape is reflected in the pattern shape and line edge roughness.

  On the other hand, in recent years, it has been proposed to use a low molecular material from the viewpoint of pattern miniaturization and low line edge roughness. For example, a phenolic compound derivative having a specific structure (see, for example, Patent Document 6 and Patent Documents 3 to 5), a calixarene having a specific structure (for example, see Patent Documents 6 and 7), a calix resorcinarene (for example, Patent Documents 7 and 8) and resist compositions using phenolic dendrimers (see, for example, Patent Document 9) having calixresorcinarene as a mother nucleus are disclosed.

However, simply using a low molecular weight material cannot simultaneously satisfy high sensitivity, high resolution, and good line edge roughness in an ultrafine region. Furthermore, regarding the outgas suppression, which is a particularly important required performance in EUV lithography, the current situation is that sufficient studies have not been made.
European Patent No. 1480078 specification US Pat. No. 6,680,157 JP-A-10-83073 JP 2000-305270 A JP 2003-183227 A JP-A-10-120610 JP-A-11-322656 JP 2003-321423 A JP-A-10-310545

  An object of the present invention is to solve the problem of performance improvement technology in microfabrication of a semiconductor device using actinic rays or radiation such as high energy rays, X-rays, electron beams or EUV light. An object of the present invention is to provide a resist composition that satisfies image quality and good line edge roughness, and at the same time satisfies a reduction in outgas, and a pattern forming method using the same.

The present invention is as follows.
As a result of intensive studies, the inventors of the present invention contain a photoacid generator having a specific structure, a compound that generates a compound having a specific structure by irradiation with actinic rays or radiation, and a group that generates an alkali-soluble group by the action of an acid. This was achieved by a resist composition in combination with a low molecular compound having a specific structure.
That is, the present invention is achieved by the following configuration.

(1)
(Z) comprising a compound having a sulfonium cation having a structure represented by the general formula (Z-I), and (T) a low molecular weight compound whose solubility in an alkali developer is increased by the action of an acid. Positive resist composition.

In general formula (Z-I),
Y ^{1 to} Y ¹³ each independently represent a hydrogen atom or a substituent, and adjacent ones may be bonded to each other to form a ring.
Z represents a single bond or a divalent linking group.
(2)
(A) The positive resist composition according to (1), which contains a compound that generates a compound having a structure represented by the following general formula (AI) upon irradiation with actinic rays or radiation.
_{Q 1 -X 1 -NH-X 2} -Q 2 (A-I)
In general formula (AI), Q ₁ and Q ₂ each independently represents a monovalent organic group. However, either Q ₁ or Q ₂ contains 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 —.
(3)
The positive resist composition as described in (2), wherein the compound having a structure represented by the general formula (AI) includes a compound having a structure represented by the following general formula (A-II): object.
_{Q 1 -X 1 -NH-X 2} -A- (X 3) n -B-Q 3 (A-II)
In general formula (A-II), Q ₁ and Q ₃ each independently represents a monovalent organic group. However, _one of Q ₁ and Q ₃ contains 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.
(4)
The positive resist composition as described in any one of (1) to (3), wherein the low molecular compound (T) is a compound having a structure represented by the following general formula (TI).

In the general formula (TI),
R ₁ , R ₂ , R ₃ and R ₄ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. A plurality of R ₁ may combine to form a ring. A plurality of R ₂ may combine to form a ring. A plurality of R ₃ may combine to form a ring. A plurality of R ₄ may combine to form a ring. A plurality of R ₁ , R ₂ , R ₃ and R ₄ may be the same or different.
R ₅ and R ₆ each independently represent a hydrogen atom or an organic group, and a plurality of R ₅ and R ₆ may be the same or different from each other. Further, at least one of the plurality of R ₅ and R ₆ is an acid-decomposable group.
W represents a group consisting of a single bond, an alkylene group, a cycloalkylene group or an arylene group, and any combination thereof.
x represents a positive integer.
y represents an integer of 0 or more. When W is a single bond, y is 0.
z represents an integer of 0 or more.
v represents an integer of 0 or more.
m1, m3, and m4 each independently represent a positive integer.
m2 and m5 each independently represent an integer of 0 or more. However, m1 + m2 + z = 5, m3 + v = 3, m4 + m5 = 5, and m2 + m5 ≧ 2.
(5)
The positive type according to (4), wherein the compound represented by the general formula (TI) is a compound represented by any one of the following general formulas (T-II) to (T-IV): Resist composition.

In general formulas (T-II) to (T-IV),
R ₁ , R ₂ , R ₅ , R ₆ , x, z, m1 and m2 have the same meaning as those in formula (TI).
R ₇ represents a hydrogen atom, an alkyl group or a cycloalkyl group. A plurality of R ₇ may combine to form a ring. A plurality of R ₇ may be the same as or different from each other.
u represents a positive integer. However, u + X = 3.
r represents a positive integer.
W ₀ represents an arylene group.
W ₁ represents a single bond, an alkylene group or a cycloalkylene group.
A represents a group having a structure represented by the following general formula (a).

In the general formula (a), R ₃ , R ₄ , R ₆ , m4 and m5 have the same meaning as those in the general formula (TI).
(6)
The positive resist composition as described in any one of (1) to (3), wherein the low molecular compound (T) is a compound having a structure represented by the following general formula (T-V).

In the general formula _{(T-V), R 1} , R 2, R 3, R 5, m4, m5 and x have the same meanings as those in formula (T-I).
(7)
The compound that generates the compound having the structure represented by the general formula (AI) is a sulfonium salt compound of the compound having the structure represented by the general formula (AI), represented by the general formula (AI). The positive resist composition as described in any one of (2) to (6), which is an iodonium salt compound of a compound having a structure as described above.
(8)
A resist pattern forming method, comprising: applying a positive resist composition according to any one of (1) to (7) to a substrate to obtain a resist film; and exposing and developing to form a resist pattern. .

  Furthermore, the following structures are mentioned as a preferable aspect.

(9)
The positive resist composition as described in any one of (1) to (7) above, further comprising (C) a basic compound and / or (D) fluorine and / or a silicon-based surfactant. .

(10)
(E) a compound in which the basic compound has a structure selected from an imidazole structure, a diazabicyclo structure, an onium hydroxy structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure and a pyridine structure, an alkyl having a hydroxyl group and / or an ether bond The photosensitive compound according to (9), which is an amine derivative or an aniline derivative having a hydroxyl group and / or an ether bond.

  The present invention is to solve the problem of the performance improvement technology in the microfabrication of semiconductor elements using high energy rays, X-rays, electron beams or EUV light, and has high sensitivity, high resolution, good pattern shape, In addition, a resist composition that simultaneously satisfies good line edge roughness and a pattern forming method therefor are provided.

Hereinafter, the present invention will be described in detail.
In addition, in the description of a group (atomic group) in this specification, the description which does not describe substituted and unsubstituted includes what has a substituent with what does not have 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).

  The positive resist composition of the present invention has (Z) a compound having a sulfonium cation having a structure represented by the general formula (ZI) and (T) an acid developer having a low solubility that increases solubility in an alkali developer by the action of an acid. Containing molecular compounds. Moreover, it is preferable to contain (A) the compound which generate | occur | produces an acid by irradiation of actinic light or a radiation.

[1] (Z) A compound having a sulfonium cation having a structure represented by the general formula (ZI) (hereinafter also referred to as “compound (Z)” or “(Z) component”)

In general formula (Z-I),
Y ^{1 to} Y ¹³ each independently represent a hydrogen atom or a substituent, and adjacent ones may be bonded to each other to form a ring.
Z represents a single bond or a divalent linking group.
In the general formula (ZI), the substituent of Y ^{1 to} Y ¹³ may be any one and is not particularly limited. For example, a halogen atom, an alkyl group, a cycloalkyl group (bicycloalkyl group, trialkyl group) Cycloalkyl groups), alkenyl groups (including cycloalkenyl groups and bicycloalkenyl groups), alkynyl groups, aryl groups, heterocyclic groups (also referred to as heterocyclic groups), cyano groups, hydroxyl groups, nitro groups, Carboxyl group, alkoxy group (including cycloalkoxy group), aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group (including cycloalkoxycarbonyloxy group), aryloxycarbonyloxy Group, amino group (including anilino group), ammonio group, acyl Mino group, aminocarbonylamino group, alkoxycarbonylamino group (including cycloalkoxycarbonylamino group), aryloxycarbonylamino group, sulfamoylamino group, alkyl, cycloalkyl or arylsulfonylamino group, mercapto group, alkylthio group ( Cycloalkylthio group), arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl, cycloalkyl or arylsulfinyl group, alkyl, cycloalkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group (Including cycloalkoxycarbonyl group), carbamoyl group, aryl or heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group Phosphinylamino group, a phosphono group, a silyl group, a hydrazino group, a ureido group, boronic acid group (-B (OH) _2), phosphato group (-OPO (OH) _2), a sulfato group (-OSO ₃ H), Other known substituents can be mentioned.

Y ^{1 to} Y ¹³ are preferably a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group (including a bicycloalkyl group or a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group or a bicycloalkenyl group), alkynyl Group, aryl group, cyano group, hydroxyl group, carboxyl group, alkoxy group (including cycloalkoxy group), aryloxy group, acyloxy group, carbamoyloxy group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group (cycloalkoxy group) Carbonylamino group), aryloxycarbonylamino group, sulfamoylamino group, alkyl, cycloalkyl or arylsulfonylamino group, alkylthio group (including cycloalkylthio group), arylthio group, sulfamoy Group, (including cycloalkoxy group) alkyl, cycloalkyl or aryl-sulfonyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an imido group, a silyl group, a ureido group.

Y ^{1 to} Y ¹³ are more preferably a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group (including a bicycloalkyl group or a tricycloalkyl group), a cyano group, a hydroxyl group, or an alkoxy group (including a cycloalkoxy group). ), Acyloxy group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group (including cycloalkoxycarbonylamino group), alkyl, cycloalkyl or arylsulfonylamino group, alkylthio group (including cycloalkylthio group), sulfamoyl group, An alkyl, cycloalkyl or arylsulfonyl group, an alkoxycarbonyl group (including a cycloalkoxycarbonyl group), and a carbamoyl group;

Y ^{1 to} Y ¹³ are particularly preferably a hydrogen atom, an alkyl group, a cycloalkyl group (including a bicycloalkyl group and a tricycloalkyl group), a cyano group, a hydroxyl group, an alkoxy group (including a cycloalkoxy group), and an alkyl group. A sulfonyl group.
Examples of the ring formed by bonding the adjacent ones of Y ^{1 to} Y ¹³ include aromatic, non-aromatic hydrocarbon rings, heterocyclic rings, and polycyclic condensed rings obtained by further combining these, For example, benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring, pyrazine ring, Pyrimidine ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole ring, phenant Lysine ring, acridine ring, Ntororin ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothiazine ring, phenazine ring, and the like.

Examples of the divalent linking group in Z include, for example, an alkylene group, an arylene group, an ether group, a thioether group, an amino group, —CH═CH—, —C≡C—, a carbonyl group, a sulfide group, a sulfone group, and a sulfoxide group. , -COO-, -CONH-, -SO ₂ NH-, -CF _2- , -CF ₂ CF _2- , -OCF ₂ O-, -CF ₂ OCF _2- , -SS-, -CH ₂ SO ₂ CH _2- , -CH ₂ COCH _2- , -COCF ₂ CO-, -COCO-, -OCOO-, -OSO ₂ O-.
Z is preferably a single bond, an alkylene group (preferably a methylene group), an ether group, a thioether group, a carbonyl group, a sulfide group, a sulfone group, —COO—, —CONH—, —SO ₂ NH—, —CF ₂ —. , —CF ₂ CF ₂ —, —COCO—, more preferably a single bond, an ether group, a thioether group, a carbonyl group, a sulfide group, or a sulfone group, and particularly preferably a single bond or a sulfone group.

The compound of component (Z) has a counter anion. The counter anion is preferably an organic anion. An organic anion is an anion having at least one carbon atom. Furthermore, the organic anion is preferably a non-nucleophilic 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.
Examples of the non-nucleophilic anion include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

Examples of the non-nucleophilic sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, a camphor sulfonate anion, and the like. Examples of the non-nucleophilic carboxylate anion include an aliphatic carboxylate anion, an aromatic carboxylate anion, and an aralkylcarboxylate anion.
The aliphatic moiety in the aliphatic sulfonate anion may be an alkyl group or a cycloalkyl group, preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms, for example, Methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, 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, etc. .

The aromatic group in the aromatic sulfonate anion is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group.
Examples of the substituent of the alkyl group, cycloalkyl group and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion include, for example, a nitro group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), 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 having 2 to 7 carbon atoms), acyl group (preferably having 2 to 12 carbon atoms), alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms) and the like can be mentioned. 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 aliphatic moiety in the aliphatic carboxylate anion include the same alkyl group and cycloalkyl group as in the aliphatic sulfonate anion.
Examples of the aromatic group in the aromatic carboxylate anion include the same aryl groups as in the aromatic sulfonate anion.
The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 6 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylmethyl group.
Examples of the substituent of the alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion include, for example, the same halogen as in the aromatic sulfonate anion. Atoms, alkyl groups, cycloalkyl groups, alkoxy groups, alkylthio groups and the like 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 for these alkyl groups include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, and an alkylthio group.
Examples of other non-nucleophilic anions include fluorinated phosphorus, fluorinated boron, and fluorinated antimony.

The counter anion of the compound of component (Z) is preferably a sulfonate anion, and more preferably an aromatic sulfonate anion.
Specific examples of counter anions include methane sulfonate anion, trifluoromethane sulfonate anion, pentafluoroethane sulfonate anion, heptafluoropropane sulfonate anion, perfluorobutane sulfonate anion, perfluorohexane sulfonate anion, perfluoro. Octane sulfonate anion, pentafluorobenzene sulfonate anion, 3,5-bistrifluoromethylbenzene sulfonate anion, 2,4,6-triisopropylbenzene sulfonate anion, perfluoroethoxyethane sulfonate anion, 2, 3, 5 , 6-tetrafluoro-4-dodecyloxybenzenesulfonate anion, p-toluenesulfonate anion, pentafluorobenzenesulfonate anion, camphorsulfonate anion and the like.

The counter anion that the compound of the (Z) component has together with the sulfonium cation represented by the general formula (ZI) may be monovalent or divalent. When the counter anion is divalent or more, the compound of the (Z) component can have two or more sulfonium cations represented by the general formula (Z-I).
The content of the component (Z) is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably 1 to 7%, based on the total solid content of the positive resist composition. % By mass.
The compound of component (Z) is an acid generator that generates an acid upon irradiation with actinic rays or radiation.

  Specific examples of the sulfonium salt (Z) represented by the general formula (Z-I) are shown below, but are not limited thereto.

[2] (A) A compound that generates a compound having a structure represented by the following general formula (AI) by irradiation with actinic rays or radiation (hereinafter also referred to as “compound (A)”)

_{Q 1 -X 1 -NH-X 2} -Q 2 (A-I)

In general formula (AI), Q ₁ and Q ₂ each independently represents a monovalent organic group. However, either Q ₁ or Q ₂ contains 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 —.
The monovalent organic group as Q ₁ and Q _{2 in the} general formula (AI) preferably has 1 to 40 carbon atoms, and examples thereof include 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 number of carbon atoms is preferably 4 to 30, and examples of the group containing such a structure 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 (AI), it is preferable that at least one of X ₁ and X ₂ is —SO ₂ —.
The compound having a structure represented by the general formula (AI) preferably includes a compound having a structure represented by the following general formula (A-II).

_{Q 1 -X 1 -NH-X 2} -A- (X 3) n -B-Q 3 (A-II)

In general formula (A-II),
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 (AI).
Examples of the organic group of Q ₃ include the same organic groups as Q ₁ and Q ₂ in formula (AI).

  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-II), X ₁ , X ₂ and X ₃ are preferably —SO ₂ —.
Hereinafter, although the specific example of a compound which has a structure represented by general formula (AI) is shown, this invention is not limited to this.

The compound that generates the compound having the structure represented by the general formula (AI) upon irradiation with actinic rays or radiation is a sulfonium salt compound of the compound having the structure represented by the general formula (AI) or the general formula It is preferable that it is an iodonium salt compound of the compound which has a structure represented by (AI).
The compound that generates a compound having a structure represented by the general formula (AI) upon irradiation with actinic rays or radiation is more preferably a compound represented by the following general formula (A1) or (A2).

In general formula (A1),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X < ^- > represents an anion of the compound represented by the general formula (AI) or (A-II).
The carbon number of the organic group as 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 as 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 a triarylsulfonium compound, a diarylalkylsulfonium compound, a diarylcycloalkylsulfonium compound, an aryldialkylsulfonium compound, an aryldicycloalkylsulfonium compound, and an arylalkylcycloalkylsulfonium compound.

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like. 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 aromatic ring-free organic group 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, An alkoxycarbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group. The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 20 carbon atoms, an ethyl group, a propyl 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.
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is a 2-oxocycloalkyl group is more preferable.

The linear or branched 2-oxoalkyl group as 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 as 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 as 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 on the 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 an anion of the compound represented by the general formula (AI) or (A-II).
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.

The alkyl group as R ₂₁₄ , R ₂₁₅ , Y ₂₀₁ and Y ₂₀₂ is preferably a linear or branched alkyl group having 1 to 20 carbon atoms. The alkyl group as Y ₂₀₁ and Y ₂₀₂ is 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), or a carboxyalkyl group. More preferred.
The cycloalkyl group as R ₂₁₄ , R ₂₁₅ , Y ₂₀₁ and Y ₂₀₂ is preferably a cycloalkyl group having 3 to 20 carbon atoms.

The aryl group as Y ₂₀₁ and Y ₂₀₂ is preferably a phenyl group or a naphthyl group.
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 general formula (A2),
_R204 and _R205 each independently represents an aryl group, an alkyl group or a cycloalkyl group.
X < ^- > represents an anion of the compound represented by the general formula (AI) or (A-II).
The aryl group of R ₂₀₄ and R _205, a phenyl group, a naphthyl group, more preferably a phenyl group. The aryl group of R ₂₀₄ and R ₂₀₅ may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like.

The alkyl group as _R204 and _R205 may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group).
The cycloalkyl group as R ₂₀₄ and R ₂₀₅ can preferably be mentioned a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
_R204 and _R205 may have a substituent. Examples of the substituent that R ₂₀₄ and R ₂₀₅ may have include, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 6 carbon atoms). 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

The compound (A) is preferably a compound represented by the general formula (A1), and more preferably a compound represented by the general formulas (A1a) to (A1c).
Hereinafter, although the specific example of a compound (A) is given, this invention is not limited to this.

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

Compound (A) is a novel compound.
Compound (A) 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 (AI) 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 by an amine or alcohol containing a partial structure represented by the general formula (AI). . An amine or alcohol containing a partial structure represented by the general formula (AI) 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.

[3] (T) A low molecular compound whose solubility in an alkaline developer is increased by the action of an acid (hereinafter sometimes referred to as “T component”).

  The low molecular compound (T) which decomposes by the action of an acid used in the present invention and increases the solubility in an alkaline developer is a compound formed from an aromatic ring and an alkylene chain or a cycloalkylene chain, and containing an acid-decomposable group (Binder). Especially, it is preferable that there exists a part formed by the coupling | bonding of an aromatic ring-alkylene chain-aromatic ring.

The low molecular weight compound (T) whose solubility in an alkaline developer is increased by the action of an acid used in the present invention is not a polymer. That is, a mother nucleus compound having a single molecular skeleton is substituted with a protecting group such as an acid-decomposable group. Or, it does not exhibit the molecular weight dispersion found in polymers.
Or it is a compound which has the characteristics that it does not have ten or more repeating units derived from a polymerizable monomer.
The compound of component (T) used in the present invention is preferably a compound having a structure represented by the following general formula (TI).

In the general formula (TI),
R ₁ , R ₂ , R ₃ and R ₄ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. A plurality of R ₁ may combine to form a ring. A plurality of R ₂ may combine to form a ring. A plurality of R ₃ may combine to form a ring. A plurality of R ₄ may combine to form a ring. A plurality of R ₁ , R ₂ , R ₃ and R ₄ may be the same or different.
R ₅ and R ₆ each independently represent a hydrogen atom or an organic group, and a plurality of R ₅ and R ₆ may be the same or different from each other. Further, at least one of the plurality of R ₅ and R ₆ is an acid-decomposable group.

W represents a group consisting of a single bond, an alkylene group, a cycloalkylene group or an arylene group, and any combination thereof.
x represents a positive integer.
y represents an integer of 0 or more. When W is a single bond, y is 0.
z represents an integer of 0 or more.
v represents an integer of 0 or more.
m1, m3, and m4 each independently represent a positive integer.
m2 and m5 each independently represent an integer of 0 or more. However, m1 + m2 + z = 5, m3 + v = 3, m4 + m5 = 5, and m2 + m5 ≧ 2.

The alkyl group in R ₁ , R ₂ , R ₃ and R ₄ may be linear or branched, and preferably has a carbon number such as a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a hexyl group or an octyl group. 1-10 things are mentioned.
The cycloalkyl group in R ₁ , R ₂ , R ₃ and R ₄ may be monocyclic or polycyclic. Examples thereof include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The number of carbon atoms is preferably 6 to 30, and particularly preferably 7 to 25. For example, an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group Cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecanyl group, cyclododecanyl group and the like. These alicyclic hydrocarbon groups may have a substituent.

Examples of the substituent that the alkyl group or cycloalkyl group may have include a hydroxyl group, a carboxyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), an alkoxy group (methoxy group, ethoxy group, propoxy group). , Butoxy group, etc.).
The organic group in R ₅ and R ₆ preferably represents an acid-decomposable or non-acid-decomposable group. In this invention, 1-30 acid-decomposable groups are contained in 1 molecule. The number of acid-decomposable groups contained in one molecule is preferably 3 to 25, more preferably 4 to 20.

The acid-decomposable organic group in R ₅ and R ₆ is an organic group (acid-decomposable group) that is decomposed by the action of an acid to generate an alkali-soluble group, and examples thereof include groups described later.

The non-acid-decomposable organic group in R ₅ and R ₆ is an organic group that is not decomposed by the action of an acid, such as an alkyl group, an aryl group, an aralkyl group that is not decomposed by the action of an acid, An alkoxy group, an alkoxycarbonyl group, an amide group, a cyano group, etc. can be mentioned. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group. For example, methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, hexyl group, 2-ethylhexyl group, octyl Group, cyclopropyl group, cyclobutyl group, cyclohexyl group, adamantyl group and the like. 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 alkylene group in W may be linear or branched and preferably has 1 to 10 carbon atoms, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, and an isobutylene group.
The cycloalkylene group in W may be monocyclic or polycyclic, and examples of the alkylene group forming the ring include a cycloalkylene group having 3 to 8 carbon atoms (for example, a cyclopentylene group and a cyclohexylene group). be able to.
Each of the above groups may further have a substituent, and examples of the substituent include an alkyl group (preferably having a carbon number of 1 to 10, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group). Group, sec-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc.), alkoxy group (preferably having 1 to 4 carbon atoms such as methoxy group, ethoxy group, Propoxy group, butoxy group, etc.), fluorine atom, chlorine atom, bromine atom, iodine atom and the like.

In addition, an alkylene chain or a cycloalkylene chain includes —O—, —OC (═O) —, —OC (═O) O—, —N (R) —C (═O) —, —N in the alkylene chain. (R) —C (═O) O—, —S—, —SO—, —SO ₂ — may be included. Here, R represents a hydrogen atom or an alkyl group (preferably having a carbon number of 1 to 10, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group). Group, hexyl group, heptyl group, octyl group, nonyl group, decyl group and the like.
The cyclic arylene group in W is preferably a group having 6 to 15 carbon atoms such as a phenylene group, a tolylene group, and a naphthylene group.

  The compound represented by the general formula (TI) is preferably a compound represented by any one of the following general formulas (T-II) to (T-IV).

In general formulas (T-II) to (T-IV),
R ₁ , R ₂ , R ₅ , R ₆ , X, z, m1 and m2 have the same meanings as those in the general formula (TI).
R ₇ represents a hydrogen atom, an alkyl group or a cycloalkyl group. A plurality of R ₇ may combine to form a ring. A plurality of R ₇ may be the same as or different from each other.
u represents a positive integer. However, u + X = 3.
r represents a positive integer.
W ₀ represents an arylene group.
W ₁ represents a single bond, an alkylene group or a cycloalkylene group.

  A represents the following structure.

In general formula (a), R < ₃ >, R < ₄ >, R < ₆ >, m4 and m5 are synonymous with those in general formula (TI).
The compound of component (T) used in the present invention is also preferably a calixarene derivative and calixresorcinarene derivative having a structure represented by the following general formula (T-V).

In the general formula _{(T-V), R 1} , R 2, R 3, R 5, m4, m5, and X have the same meanings as those in formula (T-I).
The low molecular weight compound (T) is obtained by reacting a phenolic hydroxyl group of a compound serving as a mother nucleus (mother nucleus compound) such as a polyhydric phenol compound with a protective reactant, and converting the phenolic hydroxyl group of the mother nucleus compound into an acid-decomposable group. It can be synthesized by protecting with. The protecting reagent here refers to a compound used in carrying out a reaction for introducing a protecting group. In addition, the ratio of the phenolic hydroxyl group protected with the acid-decomposable group with respect to the total number of phenolic hydroxyl groups contained in the mother nucleus compound is called a protection rate.
Specific examples of the mother nucleus compound of compound (T) are shown below, but the present invention is not limited thereto.

The compound containing an acid-decomposable group in one molecule of the low molecular compound (T) used in the present invention and increasing the solubility in an alkali developer by the action of an acid preferably contains an alkali-soluble group.
Examples of the alkali-soluble group include a hydroxyl group, a sulfonic acid group, a phenol group, a carboxylic acid group, and a hexafluoroisopropanol group [—C (CF ₃ ) ₂ OH]. Preferred are a phenol group, a carboxyl group, and a hexafluoroisopropanol group, and more preferred are a phenol group and a carboxyl group.
The acid-decomposable group is a substituent that replaces the hydrogen atom of OH in the alkali-soluble groups listed above, and is —C (R _11a ) (R _12a ) (R _13a ), —C (R _14a ) (R _15a ). (OR _16a ) and —CO—OC (R _11a ) (R _12a ) (R _13a ) are preferred. Here, R _{11a to} R _13a each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, or an aryl group.
R _14a and R _15a each independently represents a hydrogen atom or an alkyl group. R _16a represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group.
Two of R _11a , R _12a and R _13a , or two of R _14a , R _15a and R _16a may be bonded to form a ring.

Further, the R ₅ or R ₆ in the general formula (T-I), it can be introduced to a group having an acid-decomposable group. For example, the following groups can be exemplified.
-[C ( _R17a ) ( _R18a )] _p- CO-OC ( _R11a ) ( _R12a ) ( _R13a )
Here, R _17a and R _18a each independently represent a hydrogen atom or an alkyl group.
Moreover, p is an integer of 1-4.

  Although the preferable specific example of an acid-decomposable group is shown below, this invention is not limited to these.

  The molecular weight of the mother nucleus compound as component (T) is usually 200 to 5000, preferably 300 to 4000, more preferably 400 to 3000, and particularly preferably 400 to 1500. The mother nucleus compound of component (T) is commercially available from, for example, Honshu Chemical Industry Co., Ltd., and can be used. It can also be synthesized by condensation of various mother nucleus compounds with various aldehydes and ketones.

  The content of the component (T) is usually 50% by mass to 99.5% by mass, preferably 60% by mass to 99.0% by mass, and more preferably based on the total solid content of the positive resist composition. It is 70 mass%-98.0 mass%.

A resin (polymer) may be further added to the resist composition of the present invention. The resin to be added is an alkali-soluble resin (containing no acid-decomposable group) or an acid-decomposable resin. As the alkali-soluble resin, a homopolymer or copolymer of p-hydroxystyrene, a homopolymer or copolymer of (meth) acrylic acid, p- (1,1,1,3,3,3-hexafluoro- 2-Hydroxypropyl) styrene homopolymer or copolymer. Examples of the acid-decomposable resin include a resin obtained by protecting the alkali-soluble resin with an acid-decomposable group.
Content of resin to add is 1-50 mass% normally with respect to the solid content whole quantity of a positive resist composition, Preferably it is 5-40 mass%, More preferably, it is 10-30 mass%.

<Other components> [4] (C) Basic compound In the present invention, depending on the combination of the compound (Z), the compound (A), the low molecular compound (T) used, and the additive resin described later, (C ) It may be better to contain a basic compound.
Preferred structures of the basic compound (C) include structures represented by the following general formulas (a) to (e).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl having 1 to 20 carbons, a cycloalkyl group having 3 to 20 carbons or an aryl group having 6 to 20 carbons, R ²⁵⁰ and R ²⁵¹ may combine with each other to form a ring. These may have a substituent. 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, and 1 to 1 carbon atoms. A 20 hydroxyalkyl group or a C 3-20 hydroxycycloalkyl group is preferred.
These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.

In the formula, R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represent an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms.
Preferable compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine, and may have a substituent. More preferable compounds include compounds having an imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, trialkylamine structure, aniline structure or pyridine structure, alkylamine derivatives having a hydroxyl group and / or an ether bond, hydroxyl groups and / or Or the aniline derivative which has an ether bond etc. can be mentioned.

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, and the like. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4,0. ] Undec-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. However, when the amount of component (B) used is 0.05% by mass or more, the basic substance may or may not be used. When a basic compound is used, the amount used is usually 0.001 to 10% by mass, preferably 0.01 to 5% by mass, based on the solid content of the positive resist composition. 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.

[5] (D) Fluorine 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, It is preferable to contain any one of surfactants containing both fluorine atoms and silicon atoms, or two or more thereof.
When the positive resist composition of the present invention contains fluorine and / or a silicon-based surfactant, adhesion and development defects are obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It is possible to provide a resist pattern with less.

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

  Examples of commercially available surfactants that can be used include 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. It 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 fluorine and / or silicon 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). It is.

[6] (F) Organic solvent The positive resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent.
Examples of the organic solvent that can be used 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 -Dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc.

(Fa) Ketone solvent The solvent used in the present invention is preferably a solvent having at least one ketone structure.
Examples of the solvent having a ketone structure include a chain ketone solvent and a cyclic ketone solvent, and a compound having a total carbon number of 5 to 8 is preferable because of good coatability.
Examples of chain ketone solvents include 2-heptanone, methyl ethyl ketone, and methyl isobutyl ketone, with 2-heptanone being preferred.

Examples of the cyclic ketone solvent include cyclopentanone, 3-methyl-2-cyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, cycloheptanone, cyclooctanone, and isophorone. Are cyclohexanone and cycloheptanone.
The solvent is preferably used as a solvent having a ketone structure alone or as a mixed solvent with other solvents. Examples of the solvent to be mixed (combined solvent) include propylene glycol monoalkyl ether carboxylate, alkyl lactate, propylene glycol monoalkyl ether, alkyl alkoxypropionate, and lactone compound.

Examples of the propylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether acetate and the like.
Examples of the alkyl lactate include methyl lactate and ethyl lactate.
Examples of the propylene glycol monoalkyl ether include propylene glycol monomethyl ether and propylene glycol monoethyl ether.

Examples of the alkyl alkoxypropionate include methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, and ethyl ethoxypropionate.
Examples of the lactone compound include γ-butyrolactone.
Preferred examples of the combined solvent include propylene glycol monoalkyl ether carboxylate, alkyl lactate, and propylene glycol monoalkyl ether. More preferable examples of the combined solvent include propylene glycol monomethyl ether acetate.

By mixing the ketone solvent and the combined solvent, substrate adhesion, developability, DOF, and the like are improved.
The ratio (mass ratio) of the ketone solvent and the combined solvent is preferably 10/90 to 95/5, more preferably 20/80 to 80/20, still more preferably 30/70 to 70/30.
Moreover, you may mix the high boiling point solvent of 200 degreeC or more of boiling points, such as ethylene carbonate and a propylene carbonate, from a viewpoint of improving film thickness uniformity and development defect performance.
The addition amount of these high-boiling solvents is usually 0.1 to 15% by mass, preferably 0.5 to 10% by mass, and more preferably 1 to 5% by mass in the total solvent.

  In the present invention, the solvent is used alone, preferably two or more kinds of solvents are used, and the solid content concentration is usually 3 to 25% by mass, preferably 5 to 22% by mass, more preferably 5 to 5% by mass. A 15% by mass positive resist composition is prepared.

<Other additives>
The positive resist composition of the present invention further contains a dye, a plasticizer, a surfactant other than the above component (D), a photosensitizer, and a compound that promotes solubility in a developer as necessary. Can be made.
In the present invention, a surfactant other than the (D) fluorine-based and / or silicon-based surfactant may be added. Specifically, nonionic interfaces such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan aliphatic esters, polyoxyethylene sorbitan aliphatic esters, etc. Mention may be made of activators.
These surfactants may be added alone or in some combination.

(Pattern formation method)
The positive resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, and applying the solution on a predetermined support as follows.
For example, a positive resist composition is coated on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by a suitable coating method such as a spinner or a coater, and dried to form a photosensitive film. Form.
The photosensitive film is irradiated with actinic rays or radiation through a predetermined mask, preferably baked (heated) and developed. Thereby, a good pattern can be obtained.
Exposure (immersion exposure) may be performed by filling a liquid having a higher refractive index than air between the photosensitive film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc., particularly preferably ArF excimer laser, F ₂ excimer laser, EUV (13.5 nm), electron beam.
In the development step, an alkaline developer is used as follows. As an alkaline developer of the resist composition, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and 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, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like Alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and pihelidine can be used.

Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, the content of this invention is not limited by this.

<Synthesis Example 1 Synthesis of 10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonate (Z-1)>
10 g of thioxanthen-9-one was stirred in 40 ml of trifluoroacetic acid, and a solution prepared by mixing 5.4 ml of 30% aqueous 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. 10-Tolyl-9-oxothioxanthenium nonafluorobutanesulfonate (Z-1) is obtained by adding diisopropyl ether to the reaction solution to precipitate crystals and recrystallizing with a mixed solvent of ethyl acetate and diisopropyl ether. 3.9g was obtained.
¹ H-NMR (400 MHz, CDCl ₃ ) σ2.38 (s, 3H), 7.34 (d, 2H), 7.72 (m, 2H), 7.95 (m, 4H), 8.28 (m, 2H), 8.63 (d , 2H)

<Synthesis Example 2 Synthesis of 10-tolyl-9-oxothioxanthenium 3,5-bistrifluoromethylbenzenesulfonate (Z-2)>
To 1.5 g of 10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonate (Z-1) obtained in Synthesis Example 1, 10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonic acid 1.5 g of salt is dissolved in a methanol / water = 1/1 solution and passed through an ion exchange resin (Amberlite IRA402Cl in which anion is replaced with OH with NaOH water), 1 g of 3,5-bistrifluoromethylbenzenesulfonic acid And extracted with chloroform to obtain 1.7 g of 10-tolyl-9-oxothioxanthenium 3,5-bistrifluoromethylbenzenesulfonate (A2) having a different counter salt.
¹ H-NMR (400 MHz, CDCl ₃ ) σ2.37 (s, 3H), 7.34 (d, 2H), 7.79 (m, 3H), 7.93 (m, 4H), 8.34 (m, 4H), 8.62 (d , 2H)

<Synthesis Example 3 Synthesis of 2-acetyl-10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonate (Z-8)>
15 g of thiosalicylic acid and 20 g of 4-bromoacetophenone were stirred in 170 ml of dimethylformamide in the presence of 12 g of sodium carbonate and 0.2 g of copper catalyst for 6 hours at 170 ° C. Then, the reaction solution was poured into an aqueous hydrochloric acid solution and collected by filtration. The obtained crystals were recrystallized from acetonitrile to obtain 16 g of sulfide. 10 g of the obtained sulfide was stirred in 60 g of polyphosphoric acid at 60 degrees for 5 hours, and then poured into ice water. The crystals were collected by filtration, washed with an aqueous sodium hydrogen carbonate solution and water, and recrystallized with ethanol to obtain 5 g of 2-acetyl-9H-thioxan-9-one. Further, 3 g of the obtained 2-acetyl-9H-thioxan-9-one was stirred in 12 ml of trifluoroacetic acid under ice-cooling, and a mixed solution of 1.4 ml of 30% hydrogen peroxide and 2.7 ml of trifluoroacetic acid was slowly added. added. After the addition, the mixture was stirred for 30 minutes under ice cooling, followed by stirring at room temperature for 1 hour to complete the reaction. The reaction solution was poured into water, and separated with ethyl acetate and an aqueous sodium hydroxide solution, and the organic layer was distilled off under reduced pressure to obtain 3.6 g of a sulfoxide form. It was stirred in 15 g of toluene, 3.3 ml of trifluoroacetic anhydride and 1.9 ml of nonafluorobutanesulfonic acid were added under ice cooling, and the mixture was stirred at room temperature for 30 minutes and at room temperature for 1 hour. Diisopropyl ether is added to the reaction solution for crystallization, and the resulting crystal is recrystallized with a mixed solvent of ethyl acetate and diisopropyl ether to give 2-acetyl-10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonic acid. 1 g of salt (A8) was obtained.
¹ H-NMR (400 MHz, CDCl ₃ ) σ2.39 (s, 3H), 2.74 (s, 3H), 7.37 (d, 2H), 7.72 (m, 2H), 7.97 (m, 2H), 8.19 (m , 1H), 8.39 (m, 2H), 8.67 (d, 1H), 9.09 (s, 1H)

<Synthesis Example 4 (Z-40)>
20 g of thianthrene was refluxed in 300 ml of acetic acid, and 36 ml of diluted nitric acid was slowly added dropwise thereto. After reacting for 5 hours, the reaction solution was poured into 1.2 l of water to precipitate crystals. The crystals were filtered and recrystallized from acetonitrile to obtain 12 g of thianslene-S-oxide.
¹ H-NMR (400 MHz, CDCl ₃ ) σ7.42 (t, 2H), 7.56 (t, 2H), 7.63 (d, 2H), 7.93 (d, 2H)
Thianthrene-S-oxide (2 g) was dissolved in 10 ml of toluene and cooled on ice. Thereto, 2.8 ml of trifluoroacetic anhydride and 1.2 ml of nonafluorobutanesulfonic acid were added and stirred for 1 hour. Diisopropyl ether was added and the supernatant was removed, followed by purification with a silica gel column (chloroform / methanol = 19/1) to obtain 4.4 g of 5- (p-tolyl) thianthrenium nonafluorobutanesulfonate.
¹ H-NMR (400 MHz, CDCl ₃ ) σ2.34 (s, 3H), 7.08 (d, 2H), 7.22 (d, 2H), 7.78 (m, 6H), 8.65 (d, 2H)

2 g of 5- (p-tolyl) thianthrenium nonafluorobutanesulfonate was suspended in 6 ml of trifluoroacetic acid, and 0.75 ml of 30% aqueous hydrogen peroxide was added dropwise at room temperature. Then, it stirred at 80 degreeC for 1 hour, water and chloroform were added and liquid separation was performed. After the chloroform layer was distilled off under reduced pressure, purification was performed with a silica gel column (chloroform / methanol = 19/1) to obtain 1.2 g of (Z-40).
¹ H-NMR (400 MHz, CDCl ₃ ) σ2.47 (s, 3H), 7.47 (d, 2H), 7.66 (d, 2H), 7.98 (t, 2H), 8.04 (t, 2H), 8.40 (d , 2H), 8.43 (d, 2H)

<Synthesis of Synthesis Example 5 (Z-73)>
1 g of thianslene-S-oxide was mixed with 1.1 ml of ethoxybenzene and cooled on ice. Thereto were added 1.2 ml of trifluoroacetic anhydride and 0.71 ml of nonafluorobutanesulfonic acid, and the mixture was stirred for 15 minutes. Diisopropyl ether was added and the supernatant was removed, followed by separation with chloroform and water. The chloroform layer was distilled off under reduced pressure to obtain 2.5 g of 5- (p-ethoxybenzene) thianthrenium nonafluorobutanesulfonate.
¹ H-NMR (400 MHz, CDCl ₃ ) σ1.38 (t, 3H), 4.00 (q, 2H), 6.92 (d, 2H), 7.29 (d, 2H), 7.75 (m, 6H), 8.56 (d , 2H)

2.5 g of 5- (p-ethoxybenzene) thianthrenium nonafluorobutanesulfonate was suspended in 10 ml of trifluoroacetic acid and cooled on ice. Thereto was added dropwise 0.89 ml of 30% hydrogen peroxide and stirred for 1 hour. After the reaction, the reaction solution was poured into water, and further chloroform was added for liquid separation. The chloroform layer was distilled off under reduced pressure and recrystallized with a mixed solvent of diisopropyl ether and ethyl acetate to obtain 1.3 g of (Z-73).
¹ H-NMR (400 MHz, CDCl ₃ ) σ1.47 (t, 3H), 4.20 (q, 2H), 7.26 (d, 2H), 7.91 (m, 6H), 7.98 (m, 2H), 8.39 (d , 2H)

  Compounds other than the above among (Z-1) to (Z-105) were synthesized in the same manner. On the other hand, the compounds (Z-106) to (Z-121) were synthesized by a known method described in JP-A-2003-149800 and the like.

<Synthesis Example of Compound (A)>
Synthesis Example 1 (Synthesis of Compound (A-1))
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 on ice, 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. The reaction solution was neutralized with concentrated hydrochloric acid under BR> H, 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.

16.1 g (46.9 mmol) of triphenylsulfonium bromide and 12.4 g (53.5 mmol) of silver oxide were 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 the residue was dried to obtain 20.9 g of a white solid compound (A-1).
¹ H-NMR (400 MHz, CD ₃ OD) 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 2 (Synthesis of Compound (A-6))
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-6).
¹ H-NMR (400 MHz, CD ₃ OD) δ 1.84 (s, 3H), 6.63 (d, 2H), 7.63 (d, 2H), 7.78-7.87 (m, 15H)

Synthesis Example 3 (Synthesis of Compound (A-8))
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. 25 mL of methanol and 60 mL of 1.5N HCl were neutralized, and the precipitated white solid was filtered to obtain 5.65 g of the following compound.

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 200 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-8) (4.56 g) as a white solid. Obtained.
¹ H-NMR (400 MHz, CDCl ₃ ) δ 2.32 (s, 3H), 2.50 (m, 4H), 3.55 (m, 4H), 7.65-7.80 (m, 15H)
¹⁹ F-NMR (400 MHz, CDCl ₃ ) δ -118.5 (m, 2F), -112.3 (m, 2F), -111.1 (m, 2F), -78.6 (m 3F)

  Other compounds (A) were synthesized in the same manner.

<Example of binder T synthesis>
Synthesis Example 1 (Synthesis of binder (T-1))
In the reaction vessel, 35.74 g (0.05 mol) of the mother nucleus compound (1) shown below, 200 g of PGMEA, 41.46 g (0.05 mol) of potassium carbonate, protective reactant (4) (bromoacetic acid t-Bu ester) 40 .96 g (0.21 mol) was added and the reaction solution was heated to 100 ° C. After stirring for 3 hours, the reaction solution was allowed to cool to room temperature, neutralized by adding an aqueous 0.1N HCl solution, and washed by adding 50 ml of ethyl acetate and 50 ml of distilled water. Then, it vacuum-dried and the binder (T-1) was obtained. ^{From 1} H and ¹³ C-NMR analysis, the protection rate against total phenolic OH was 46.3%.

Synthesis Example 2 (Synthesis of binder (T-2))
In the reaction vessel, 34.04 g (0.05 mol) of the mother nucleus compound (1) shown below, 150 ml of PGMEA, 25.04 g (0.2475 mol) of triethylamine, and 2.0 g of 4-dimethylaminopyridine were added and stirred. Thereafter, a 100 ml tetrahydrofuran solution of 54.02 g (0.2475 mol) of the protective reactant (5) (di-t-butyl dicarbonate) was added dropwise over 2 hours. After the addition, the mixture was further stirred for 3 hours, neutralized with 0.1N HCl aqueous solution, washed and extracted with 50 ml of ethyl acetate and 50 ml of distilled water. The organic layer was separated and then vacuum dried to obtain a binder (T-2). ^{From 1} H and ¹³ C-NMR analysis, the protection rate against total phenolic OH was 45.6%.

Synthesis example 3 (synthesis of binder (T-4))
In a reaction vessel, 44.16 g (0.05 mol) of the mother nucleus compound (2) shown below was dissolved in 200 g of propylene glycol monomethyl ether acetate (hereinafter abbreviated as PGMEA), and this solution was decompressed to 60 ° C. and 20 mmHg to about 40 g The solvent was distilled off with the water remaining in the system. After cooling to 20 ° C., 49.75 g (0.18 mol) of the protective reactant (1) and 2.5 g of p-toluenesulfonic acid were added and stirred at room temperature for 2 hours. Thereafter, 3.0 g of triethylamine was added for neutralization, and the washing operation was performed 3 times with 50 g of ethyl acetate and 50 g of water. Then, it vacuum-dried and the binder (T-4) was obtained. ^{From 1} H and ¹³ C-NMR analysis, the protection rate against total phenolic OH was 45.3%.

Other binders shown in Table 1 were also obtained in the same manner as in the above synthesis examples except that the mother nucleus compound and the protective reactant used were changed.
The structures of the phenolic compounds (1) to (6) and the protective reactants (1) to (6), which are mother nucleus compounds, are shown below.

Protective reactant (6)

When the protective reactants (1) to (3) and (6) are used, the phenolic OH in the phenol compounds (1) to (6) is protected with acetal. Further, when the protective reaction agent (4) is used, the phenolic OH in the phenol compounds (1) to (6) is protected with t-butoxycarbonylmethyl. Further, when the protective reaction agent (5) is used, the phenolic OH in the phenol compounds (1) to (6) is protected with t-butoxycarbonyl.
The phenolic compounds (1) to (6) and the protecting reagents (1) to (6) are all easily available or can be synthesized using conventional methods.
Table 1 summarizes the mother nucleus compound, the protective reactant and the protection rate used in the binder.
The protection rate is mol% with respect to total phenol OH.

[Example]

i) Preparation of resist composition (Example 3)
Binder (T-2) of the present invention: 1.0899 g
Additive resin (BT-1): 0.1211g
Compound Z (Z-33): 0.0759 g
Compound A (A-43): 0.009 g

  Surfactant: 0.002 g was dissolved in the solvent shown in Table 2 below to prepare a solution having a solid content concentration of 6.5% by mass. This solution was filtered through a 0.1 μm Teflon (registered trademark) filter to obtain a positive resist solution. Resist solutions of other examples and comparative examples were also obtained in the same manner as described above.

(Ii) Pattern fabrication and evaluation (EB)
Using a spin coater, the positive resist solution prepared as described above is uniformly applied on a silicon wafer that has been subjected to hexamethyldisilazane treatment, and is heated and dried at 120 ° C. for 90 seconds to obtain a positive film having a thickness of 0.15 μm. A mold resist film was formed. The resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750 manufactured by Hitachi, Ltd., acceleration voltage 50 KeV). 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. The obtained pattern was evaluated by the following method.

[sensitivity]
The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4800, manufactured by Hitachi, Ltd.). The minimum irradiation energy when resolving a 150 nm line (line: space = 1: 1) was defined as sensitivity.

[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]
A cross section of a part having a line width of 150 nm (line / space = 1: 1) was observed with an SEM (S-8840, manufactured by Hitachi, Ltd.) and evaluated according to the following criteria.
A: When the angle between the pattern side wall and the substrate and the angle between the pattern side wall and the pattern surface are both 90 ± 2 degrees.
B: The angle between the pattern side wall and the substrate is 90 ± 2 degrees, but the angle between the pattern side wall and the pattern surface is 85 degrees or more and less than 88 degrees or 92 degrees or more and less than 95 degrees. Alternatively, the angle between the pattern side wall and the pattern surface is 90 ± 2 degrees, but the angle between the pattern side wall and the substrate is 85 degrees or more and less than 88 degrees or 92 degrees or more and less than 95 degrees.
C: When the angle between the pattern side wall and the substrate and the angle between the pattern side wall and the pattern surface are both 85 degrees or more and less than 88 degrees or 92 degrees or more and less than 95 degrees.
D: When the angle between the pattern side wall and the substrate is less than 85 degrees or 95 degrees or more, when the T-top shape is seen, or when the entire pattern surface is rounded.

[Line edge roughness (LER)]
The distance from the reference line where there should be an edge using a scanning electron microscope (S-9220, manufactured by Hitachi, Ltd.) at any 30 points in the length direction of 50 μm of the 150 nm line pattern at the irradiation dose showing the sensitivity described above. Was measured, the standard deviation was obtained, and 3σ was calculated. A smaller value means better performance.

[Outgas]
Evaluation was performed based on the fluctuation rate of the film thickness when the minimum irradiation energy was applied when resolving the 150 nm line (line: space = 1: 1).
Outgas: ((film thickness before exposure) − (film thickness after exposure)) / (film thickness before exposure) × 100 The smaller this value, the better the performance.
The evaluation results are shown in Table 2.

The abbreviations shown in Table 2 are shown below.
Additive resin

  Acid generator

Basic compound N-1: Trioctylamine N-2: 1,5-diazabicyclo [4.3.0] -5-nonene N-3: 2,4,6-triphenylimidazole

Surfactant W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.)
W-3: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-4: Polyoxyethylene lauryl ether

Solvent S-1: Propylene glycol monomethyl ether acetate S-2: Propylene glycol monomethyl ether S-3: Ethyl lactate

  As shown in Table 2, the resist composition of the present invention exhibits superior characteristics with respect to changes in sensitivity, resolution, pattern shape, line edge roughness, and line width in PED in vacuum, as compared with the composition of the comparative example.

Using the resist compositions of Examples 4, 16, 17, 29, 30, 35, 44 and Comparative Examples 1 to 5, resist films were obtained in the same manner as in Example 1. The obtained resist film was subjected to surface exposure using EUV light (wavelength: 13.5 nm) while changing the exposure amount by 0.5 mJ in the range of 0 to 10.0 mJ, and further baked at 110 ° C. for 90 seconds. Then, using a 2.38% 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. These results were made into Examples 52-58 and Comparative Examples 6-10, respectively.
The evaluation results are shown in Table 4.

  As can be seen from the results shown in Table 4, the resist composition of the present invention is excellent in sensitivity, dissolution contrast, and outgas suppression.

Claims (8)

(Z) comprising a compound having a sulfonium cation having a structure represented by the general formula (Z-I), and (T) a low molecular weight compound whose solubility in an alkali developer is increased by the action of an acid. Positive resist composition.

In general formula (Z-I),
Y ^{1 to} Y ¹³ each independently represent a hydrogen atom or a substituent, and adjacent ones may be bonded to each other to form a ring.
Z represents a single bond or a divalent linking group. (A) The positive resist composition according to claim 1, comprising a compound that generates a compound having a structure represented by the following general formula (AI) upon irradiation with actinic rays or radiation.
_{Q 1 -X 1 -NH-X 2} -Q 2 (A-I)
In general formula (AI), Q ₁ and Q ₂ each independently represents a monovalent organic group. However, either Q ₁ or Q ₂ contains 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 —. The positive resist composition according to claim 2, wherein the compound having the structure represented by the general formula (AI) includes a compound having a structure represented by the following general formula (A-II). object.
_{Q 1 -X 1 -NH-X 2} -A- (X 3) n -B-Q 3 (A-II)
In general formula (A-II), Q ₁ and Q ₃ each independently represents a monovalent organic group. However, _one of Q ₁ and Q ₃ contains 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. The positive resist composition according to claim 1, wherein the low molecular compound (T) is a compound having a structure represented by the following general formula (TI).

In the general formula (TI),
R ₁ , R ₂ , R ₃ and R ₄ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. A plurality of R ₁ may combine to form a ring. A plurality of R ₂ may combine to form a ring. A plurality of R ₃ may combine to form a ring. A plurality of R ₄ may combine to form a ring. A plurality of R ₁ , R ₂ , R ₃ and R ₄ may be the same or different.
R ₅ and R ₆ each independently represent a hydrogen atom or an organic group, and a plurality of R ₅ and R ₆ may be the same or different from each other. Further, at least one of the plurality of R ₅ and R ₆ is an acid-decomposable group.
W represents a group consisting of a single bond, an alkylene group, a cycloalkylene group or an arylene group, and any combination thereof.
x represents a positive integer.
y represents an integer of 0 or more. When W is a single bond, y is 0.
z represents an integer of 0 or more.
v represents an integer of 0 or more.
m1, m3, and m4 each independently represent a positive integer.
m2 and m5 each independently represent an integer of 0 or more. However, m1 + m2 + z = 5, m3 + v = 3, m4 + m5 = 5, and m2 + m5 ≧ 2. The compound represented by the general formula (TI) is a compound represented by any one of the following general formulas (T-II) to (T-IV). Resist composition.

In general formulas (T-II) to (T-IV),
R ₁ , R ₂ , R ₅ , R ₆ , x, z, m1 and m2 have the same meaning as those in formula (TI).
R ₇ represents a hydrogen atom, an alkyl group or a cycloalkyl group. A plurality of R ₇ may combine to form a ring. A plurality of R ₇ may be the same as or different from each other.
u represents a positive integer. However, u + X = 3.
r represents a positive integer.
W ₀ represents an arylene group.
W ₁ represents a single bond, an alkylene group or a cycloalkylene group.
A represents a group having a structure represented by the following general formula (a).

In the general formula (a), R ₃ , R ₄ , R ₆ , m4 and m5 have the same meaning as those in the general formula (TI). The positive resist composition according to claim 1, wherein the low molecular compound (T) is a compound having a structure represented by the following general formula (T-V).

In the general formula _{(T-V), R 1} , R 2, R 3, R 5, m4, m5 and x have the same meanings as those in formula (T-I).   The compound that generates the compound having the structure represented by the general formula (AI) is a sulfonium salt compound of the compound having the structure represented by the general formula (AI), represented by the general formula (AI). The positive resist composition according to claim 2, wherein the positive resist composition is an iodonium salt compound of a compound having a structure as described above.   A resist pattern forming method, comprising: applying a positive resist composition according to claim 1 to a substrate to obtain a resist film; and exposing and developing to form a resist pattern.