JP2005274878A - Positive type resist composition for electron beam, x ray or euv ray, and pattern forming method using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive type resist composition for pattern formation by the action of an electron beam, an X ray or EUV rays (Extreme Ultraviolet, with a wavelength in the vicinity of 13 nm), which is excellent in its sensitivity, resolution and pattern shape, has little line edge roughness and further is excellent in its sensitivity and surface roughness even under EUV irradiation, and a pattern forming method using the same. <P>SOLUTION: The positive type resist composition for the electron beam, the X ray or the EUV rays is the resist composition including at least two kinds of resins of which the solubility in an alkali developer is increased by the action of an acid (A) and a compound which generates an acid by the irradiation of the electron beam, the X ray or the EUV rays (B). and is characterized by having the two kinds of resins each containing repeating units with completely identical structures, each having specified repeating units and having mutually different contents of the specified repeating units. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a positive resist composition for electron beam, X-ray or EUV light used for manufacturing semiconductor integrated circuit elements, integrated circuit manufacturing masks and the like.

  A chemically amplified positive resist composition, known as a positive photoresist composition, generates an acid in an exposed area by irradiation with radiation such as far ultraviolet light, and is irradiated with actinic radiation by a reaction using this acid as a catalyst. This is a pattern forming material for changing the solubility of the portion and the non-irradiated portion in the developer to form a pattern on the substrate.

  The chemically amplified positive resist composition comprises a three-component system comprising an alkali-soluble resin, a compound that generates an acid upon exposure to radiation (photoacid generator), and a dissolution-inhibiting compound for the alkali-soluble resin having an acid-decomposable group. A two-component system composed of a resin having a group that is decomposed by reaction with an acid and becomes alkali-soluble and a photoacid generator, a resin having a group that is decomposed by reaction with an acid and becomes alkali-soluble, and acid-decomposable It can be roughly classified into a hybrid system comprising a low-molecular dissolution inhibiting compound having a group and a photoacid generator.

In Patent Document 1 (Japanese Patent Laid-Open No. 9-319092), a resin having an acetal group having an oxy linkage introduced therein is disclosed as having an effect of reducing standing waves.
Patent Document 2 (Japanese Patent Laid-Open No. 10-221854) discloses a resin having a unit of a substituted acetal group.

Patent Document 3 (Japanese Patent Laid-Open No. 2002-323768) and Patent Document 4 (Japanese Patent Laid-Open No. 2003-177537) describe an electron beam and an X-ray using an acid-decomposable PHS polymer having a specific bulky acetal structure. , A positive resist composition for EUV light is disclosed.
Further, as EUV exposure resists, resists containing an acid-decomposable resin having an acetal structure (Cited document 5), resists containing a resin containing (meth) acrylic acid ester (cited document 6), and the like have been proposed. .

However, when these resins having an acetal group are used as an electron beam resist, the influence of electron beam backscattering appears strongly, and the resulting resist pattern has a reverse taper profile. Furthermore, improvement in sensitivity, resolution, and improvement in the shape of the line edge portion (line edge roughness) have been desired.
Further, in pattern formation by EUV irradiation, improvement in surface roughness as well as high sensitivity has been desired.

JP 9-319092 A JP-A-10-221854 JP 2002-323768 A JP 2003-177537 A JP 2003-280199 A JP 2003-140361 A

The object of the present invention is to form an electron beam, X-ray or EUV (Extreme Ultraviolet: wavelength of around 13 nm) for pattern formation. The sensitivity, resolution and pattern shape are good, the line edge roughness is small, and further, in EUV irradiation. Another object of the present invention is to provide a positive resist composition having good sensitivity and surface roughness and a pattern forming method using the same.

As a result of intensive studies in view of the present situation, the present inventor has found that the above object can be achieved by using two kinds of resins having specific repeating units and consisting of completely common repeating units. .
That is, the positive resist composition and the pattern formation method using the same according to the present invention have the following configurations.

  (1) (A) contains at least two resins whose solubility in an alkaline developer is increased by the action of an acid, and (B) a compound that generates an acid upon irradiation with an electron beam, X-ray or EUV light. It is a resist composition, and the two types of resins have the same repeating unit structure, and have a repeating unit represented by the general formula (A1) and a repeating unit represented by the general formula (A2). However, a positive resist composition for electron beam, X-ray or EUV, wherein the content of the repeating unit represented by formula (A2) is different.

In general formulas (A1) and (A2),
Z represents a hydroxyl group, a halogen atom, a cyano group, a nitro group, an acyl group or an acyloxy group.
A ₁ represents a group containing a cyclic carbon structure and decomposing by the action of an acid.
m and n each independently represent 0-4.

  (2) The group represented by the group represented by the following general formula (X1) and the group represented by the general formula (X2) as the repeating unit represented by the general formula (A2) in at least one of the two resins (A) The positive resist composition for electron beam, X-ray or EUV according to the above (1), characterized by comprising at least one of the following.

In formulas (X1) and (X2),
R ₁ and R ₂ each independently represents a hydrogen atom or an alkyl group (preferably having 1 to 4 carbon atoms).
R ₃ and R ₄ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
m represents an integer of 0 to 20.
W represents a divalent linking group.
Y represents —O—, —OCO—, —COO—, —NHCO—, —CONH—, —S—, —SO ₂ —, or —SO ₃ —.
Z _a represents a group having a cycloalkyl group or a group having an aryl group.

  (3) In the positive resist composition as described in (1) or (2) above, the content of the repeating unit represented by the general formula (A2) is different by 5 to 50 mol% for the two types of resins (A). The positive resist composition for electron beam, X-ray or EUV described in (1) or (2) above.

(4) The above (1), wherein the content of the compound (B) that generates an acid upon irradiation with electron beam, X-ray or EUV light is 6 to 20% by mass with respect to the total solid content of the resist composition. The positive resist composition for electron beam, X-ray or EUV according to any one of (1) to (3).
(5) Compound (B) that generates acid upon irradiation with electron beam, X-ray or EUV light, and compound that generates sulfonic acid upon irradiation with electron beam, X-ray or EUV light, and electron beam, X-ray or EUV light A positive resist composition for electron beam, X-ray or EUV according to any one of the above (1) to (4), which comprises a compound that generates a carboxylic acid upon irradiation of.
(6) A pattern forming method, wherein the positive resist composition according to any one of (1) to (5) is irradiated with an electron beam, an X-ray or EUV light and developed.

  According to the present invention, it is possible to provide a positive resist composition that is excellent in sensitivity and resolution as well as pattern shape and line edge roughness with respect to pattern formation by irradiation with an electron beam, X-ray or EUV light.

Hereinafter, the present invention will be described in detail.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what 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).

[1] (A) A resin containing two types of resins that decomposes by the action of an acid and increases the solubility in an alkali developer. Decomposes by the action of the acid of the present invention and increases the solubility in an alkali developer. The resin (resin A) contains two types of resins having the same repeating unit structure. That is, the resin (A) has a repeating unit represented by the general formula (A1) and a repeating unit represented by the general formula (A2), and the structure of the repeating unit is the same, and the general formula (A1) And the total content rate of the repeating unit represented by (A2) is the same, but contains 2 types of resin from which the content rate ratio of (A1) and (A2) differs.

In general formulas (A1) and (A2), Z represents a hydroxyl group, a halogen atom, a cyano group, a nitro group, an acyl group, or an acyloxy group.
The acyl group as Z preferably has 1 to 10 carbon atoms, and examples thereof include a formyl group, an acetyl group, and a propanoyl group.
The acyloxy group as Z preferably has 2 to 15 carbon atoms, and examples thereof include an acetoxy group, a propanoyloxy group, and a benzoyloxy group.
A ₁ represents a group containing a cyclic carbon structure that is decomposed by the action of an acid (a group that is decomposed by the action of an acid to produce an alkali-soluble group), and preferably has 6 to 20 carbon atoms.
m and n each independently represent 0-4.

The general formula (A2) preferably has a group represented by the general formula (X1) or (X2). In particular, the group constituted as —OA ₁ in the general formula (A2) is preferably a group represented by the general formula (X1) or (X2).
The group represented by the general formula (X1) or (X2) preferably has 6 to 20 carbon atoms.

The alkyl group as R ₁ and R ₂ in the general formula (X1) is preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a t-butyl group. Groups and the like.
At least one of R ₁ and R ₂ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms.

R ₃ and R ₄ may be the same or different and each represents a hydrogen atom, an alkyl group or a cycloalkyl group.
The alkyl group as R ₃ and R ₄ may be linear or branched. As a linear alkyl group, Preferably it is C1-C30, More preferably, it is 1-20, for example, a methyl group, an ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl. Group, n-heptyl group, n-octyl group, n-nonyl group, n-decanyl group and the like. As a branched alkyl group, Preferably it is C1-C30, More preferably, it is 1-20, for example, i-propyl group, i-butyl group, t-butyl group, i-pentyl group, t-pentyl group, Examples include i-hexyl group, t-hexyl group, i-heptyl group, t-heptyl group, i-octyl group, t-octyl group, i-nonyl group, t-decanoyl group and the like.
The cycloalkyl group as R ₃ and R ₄ preferably has 3 to 30 carbon atoms, more preferably 3 to 20, for example, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl. Group, cyclononyl group, cyclodecanoyl group and the like.

Examples of the aryl group of the Z _a in the general formula (X1), preferably 6 to 30 carbon atoms, more preferably from 6 to 20 carbon atoms, e.g., phenyl, 4-methylphenyl, 3-methylphenyl group 2-methylphenyl group, 4-ethylphenyl group, 3-ethylphenyl group, 2-ethylphenyl group, 4-n-propylphenyl group, 3-n-propylphenyl group, 2-n-propylphenyl group, 4 -I-propylphenyl group, 3-i-propylphenyl group, 2-i-propylphenyl group, 4-cyclopropylphenyl group, 3-cyclopropylphenyl group, 2-cyclopropylphenyl group, 4-n-butylphenyl Group, 3-n-butylphenyl group, 2-n-butylphenyl group, 4-i-butylphenyl group, 3-i-butylphenyl group, 2-i- Tilphenyl group, 4-t-butylphenyl group, 3-t-butylphenyl group, 2-t-butylphenyl group, 4-cyclobutylphenyl group, 3-cyclobutylphenyl group, 2-cyclobutylphenyl group, 4- Cyclopentylphenyl group, 4-cyclohexylphenyl group, 4-cycloheptenylphenyl group, 4-cyclooctanylphenyl group, 2-cyclopentylphenyl group, 2-cyclohexylphenyl group, 2-cycloheptenylphenyl group, 2-cycloocta Nylphenyl, 3-cyclopentylphenyl, 3-cyclohexylphenyl, 3-cycloheptenylphenyl, 3-cyclooctanylphenyl, 4-cyclopentyloxyphenyl, 4-cyclohexyloxyphenyl, 4-cyclohept Tenyloxyphenyl group Crooctanyloxyphenyl group, 2-cyclopentyloxyphenyl group, 2-cyclohexyloxyphenyl group, 2-cycloheptenyloxyphenyl group, 2-cyclooctanyloxyphenyl group, 3-cyclopentyloxyphenyl group, 3-cyclohexyloxy Phenyl group, 3-cycloheptenyloxyphenyl group, 3-cyclooctanyloxyphenyl group, 4-n-pentylphenyl group, 4-n-hexylphenyl group, 4-n-heptenylphenyl group, 4-n- Octanylphenyl group, 2-n-pentylphenyl group, 2-n-hexylphenyl group, 2-n-heptenylphenyl group, 2-n-octanylphenyl group, 3-n-pentylphenyl group, 3-n -Hexylphenyl group, 3-n-heptenylphenyl group, 3-n-octanyl group Nyl group, 2,6-di-isopropylphenyl group, 2,3-di-isopropylphenyl group, 2,4-di-isopropylphenyl group, 3,4-di-isopropylphenyl group, 3,6-di-t -Butylphenyl group, 2,3-di-t-butylphenyl group, 2,4-di-t-butylphenyl group, 3,4-di-t-butylphenyl group, 2,6-di-n-butyl Phenyl group, 2,3-di-n-butylphenyl group, 2,4-di-n-butylphenyl group, 3,4-di-n-butylphenyl group, 2,6-di-i-butylphenyl group 2,3-di-i-butylphenyl group, 2,4-di-i-butylphenyl group, 3,4-di-i-butylphenyl group, 2,6-di-t-amylphenyl group, 2 , 3-di-t-amylphenyl group, 2,4-di-t-amylphenyl group, 3 4-di-t-amylphenyl group, 2,6-di-i-amylphenyl group, 2,3-di-i-amylphenyl group, 2,4-di-i-amylphenyl group, 3,4- Di-i-amylphenyl group, 2,6-di-n-pentylphenyl group, 2,3-di-n-pentylphenyl group, 2,4-di-n-pentylphenyl group, 3,4-di- n-pentylphenyl group, 4-adamantylphenyl group, 2-adamantylphenyl group, 4-isoboronylphenyl group, 3-isoboronylphenyl group, 2-isobornylphenyl group, 4-cyclopentyloxyphenyl group, 4 -Cyclohexyloxyphenyl group, 4-cycloheptenyloxyphenyl group, 4-cyclooctanyloxyphenyl group, 2-cyclopentyloxyphenyl group, 2-cyclohexyloxyphenyl group Group, 2-cycloheptenyloxyphenyl group, 2-cyclooctanyloxyphenyl group, 3-cyclopentyloxyphenyl group, 3-cyclohexyloxyphenyl group, 3-cycloheptenyloxyphenyl group, 3-cyclooctenyloxyphenyl group Group, 4-n-pentyloxyphenyl group, 4-n-hexyloxyphenyl group, 4-n-heptenyloxyphenyl group, 4-n-octanyloxyphenyl group, 2-n-pentyloxyphenyl group, 2 -N-hexyloxyphenyl group, 2-n-heptenyloxyphenyl group, 2-n-octanyloxyphenyl group, 3-n-pentyloxyphenyl group, 3-n-hexyloxyphenyl group, 3-n- Heptenyloxyphenyl group, 3-n-octanyloxyphenyl group, 2,6-di-isopropyl Pyroxyphenyl group, 2,3-di-isopropyloxyphenyl group, 2,4-di-isopropyloxyphenyl group, 3,4-di-isopropyloxyphenyl group, 2,6-di-t-butyloxyphenyl group 2,3-di-t-butyloxyphenyl group, 2,4-di-t-butyloxyphenyl group, 3,4-di-t-butyloxyphenyl group, 2,6-di-n-butyloxy Phenyl group, 2,3-di-n-butyloxyphenyl group, 2,4-di-n-butyloxyphenyl group, 3,4-di-n-butyloxyphenyl group, 2,6-di-i- Butyloxyphenyl group, 2,3-di-i-butyloxyphenyl group, 2,4-di-i-butyloxyphenyl group, 3,4-di-i-butyloxyphenyl group, 2,6-di- t-Amyloxyphenyl 2,3-di-t-amyloxyphenyl group, 2,4-di-t-amyloxyphenyl group, 3,4-di-t-amyloxyphenyl group, 2,6-di-i-amyloxy Phenyl group, 2,3-di-i-amyloxyphenyl group, 2,4-di-i-amyloxyphenyl group, 3,4-di-i-amyloxyphenyl group, 2,6-di-n- Pentyloxyphenyl group, 2,3-di-n-pentyloxyphenyl group, 2,4-di-n-pentyloxyphenyl group, 3,4-di-n-pentyloxyphenyl group, 4-adamantyloxyphenyl group , 3-adamantyloxyphenyl group, 2-adamantyloxyphenyl group, 4-isoboronyloxyphenyl group, 3-isoboronyloxyphenyl group, 2-isoboronyloxyphenyl group, etc. These may be further substituted as long as they are within the above range, and are not limited to substituents other than the above examples.

Cycloalkyl group Z _a have, even monocyclic, may be a polycyclic, it may be a bridged type. For example, the cycloalkyl group may have a bridged structure. Moreover, these groups may have a substituent. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These cycloalkyls may have a substituent. Specific examples of the alicyclic structure of the cycloalkyl group include cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclododecane, and the following structures.

Preferred examples of the alicyclic moiety include an adamantyl group, a noradamantyl group, a decalin group, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecanyl group. And cyclododecanyl group. More preferred are an adamantyl group, a decalin group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, a cyclododecanyl group, and a tricyclodecanyl group.

  Examples of the substituent of these alicyclic structures include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably a methyl group, an ethyl group, a propyl group, or an isopropyl group. Preferred examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the substituent that the alkyl group and the alkoxy group may have include a hydroxyl group, a halogen atom, and an alkoxy group (preferably having 1 to 4 carbon atoms).

  Further, the further substituents that the above group may have include a hydroxyl group, a halogen atom (fluorine, chlorine, bromine, iodine), a nitro group, a cyano group, the above alkyl group, a methoxy group, an ethoxy group, Hydroxyethoxy group, propoxy group, hydroxypropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, alkoxy group such as t-butoxy group, alkoxycarbonyl group such as methoxycarbonyl group, ethoxycarbonyl group, benzyl group, phenethyl Group, aralkyl group such as cumyl group, aralkyloxy group, formyl group, acetyl group, butyryl group, benzoyl group, cyanamyl group, acyl group such as valeryl group, acyloxy group such as butyryloxy group, the above alkenyl group, vinyloxy group, Such as propenyloxy group, allyloxy group, butenyloxy group, etc. Rukeniruokishi group, said aryl group, an aryloxy group such as phenoxy group, and an aryloxycarbonyl group such as benzoyloxy group.

The Z substituent optionally possessed alicyclic structure cycloalkyl group has as _a is preferably an alkyl group having 1 to 20 carbon atoms, an aryl group or a carbon of 6 to 20 carbon atoms 7-20 Is an aralkyl group. These substituents may further have a substituent.

  Specific examples of the group represented by the general formula (X1) are shown below, but are not limited thereto.

In general formula (X2),
The alkyl group as R ₁ and R ₂ are the same alkyl group as R ₁ and R ₂ in the general formula (X1) and the like.
The divalent linking group as W preferably has 1 to 10 carbon atoms, and includes, for example, a linear, branched or cyclic alkylene group, an arylene group, a heteroarylene group, an aralkylene group, and —S—, —C. (═O) —, —N (R ₇ ) —, —SO—, —SO ₂ —, —CO ₂ —, —N (R ₇ ) SO ₂ — or a divalent combination of two or more of these groups The group can be mentioned. Here, R ₇ can include a hydrogen atom or an alkyl group (specific examples of the alkyl group include those similar to the above R ₁ ).

Z _a in the general formula (X2) has the same definition as Z _a in the formula (X1).

In the general formula (X2), at least _one of R ₁ and R ₂ is preferably a linear or branched alkyl group having 2 to 4 carbon atoms.

  Specific examples of the group represented by the general formula (X2) are shown below, but are not limited thereto.

  Specific examples of the repeating unit represented by formula (A2) are shown below, but are not limited thereto.

As for content of the repeating unit shown by general formula (A2) in resin (A), 10-60 mol% is preferable with respect to all the repeating units, More preferably, it is 15-35 mol%.
As for content of the repeating unit shown by general formula (A1) in resin (A), 50-90 mol% is preferable with respect to all the repeating units, More preferably, it is 60-85 mol%.
The repeating unit represented by the general formula (A1) and the repeating unit represented by (A2) are usually 50:50 to 92: 8, preferably 60:40 to 90:10 in terms of molar ratio (A1: A2). Preferably it is 70: 30-85: 15.

The total amount of the repeating unit represented by the general formula (A1) and the repeating unit represented by the general formula (A2) in the resin (A) is preferably 50 to 100 mol%, more preferably based on all repeating units. Is 80 to 100 mol%.
The repeating unit that the resin (A) may contain in addition to the repeating unit represented by the general formula (A1) or (A2) is not particularly limited.

Two or more kinds of resins (A) contained in the resist composition of the present invention are common to all kinds of repeating units contained, but the content of each repeating unit is at least two kinds of resins. Among (A), the molar content of the repeating unit represented by the general formula (A2) is different, and is preferably different by 5 mol% or more.
Here, regarding the two types of resins (A), the molar content of the repeating unit represented by the general formula (A2) is different by 5 mol% or more. That is, the resins A ₁ and A which are the two types of resins (A) For each of ₂ , the content of the repeating unit represented by the general formula (A2) with respect to all repeating units constituting the resin is A ₁ and A ₂ (mol%), respectively.
| A ₁ −A ₂ | ≧ 5 mol%.
About 2 types of resin (A), it is preferable that the molar content rate of the repeating unit represented by general formula (A2) differs 5 to 50 mol%, More preferably, it is 10 to 30 mol%.

  The resin (A) may contain other acid-decomposable groups in addition to the group represented by the general formula (X1) or (X2).

  Specific examples of the resin having the repeating unit represented by the general formula (A1) and the repeating unit represented by the general formula (A2) and having increased solubility in an alkali developer by the action of an acid are shown below. However, it is not limited to these.

Resin (A) can be obtained by synthesizing the corresponding vinyl ether and reacting it with a phenolic hydroxyl group-containing alkali-soluble resin dissolved in an appropriate solvent such as tetrahydrofuran by a known method. The reaction is usually carried out in the presence of an acidic catalyst, preferably an acidic ion exchange resin, hydrochloric acid, p-toluenesulfonic acid, or a salt such as pyridinium tosylate. The corresponding vinyl ether can be synthesized from an active raw material such as chloroethyl vinyl ether by a method such as a nucleophilic substitution reaction or can be synthesized using a mercury or palladium catalyst.
As another method, it can also be synthesized by a method of acetal exchange using a corresponding alcohol and vinyl ether. In this case, the substituent to be introduced is given to the alcohol, the vinyl ether is mixed with a relatively unstable vinyl ether such as t-butyl vinyl ether, and the reaction is carried out in the presence of an acid such as p-toluenesulfonic acid or pyridinium tosylate. .

  The weight average molecular weight of the resin (A) is preferably 3000 to 80000, more preferably 5000 to 50000. The range of molecular weight distribution (Mw / Mn) is 1.01 to 4.0, preferably 1.05 to 3.00. In order to obtain a polymer having such a molecular weight distribution, it is preferable to use a technique such as anionic polymerization or radical polymerization.

  Further, the dispersity (Mw / Mn) is preferably 1.0 to 4.0, more preferably 1.0 to 3.5, and particularly preferably 1.0 to 3.0. , Heat resistance and image formability (pattern profile, defocus latitude, etc.) are improved.

[2] (B) Compound that generates acid upon irradiation with electron beam, X-ray or EUV light As a compound (acid generator) that generates acid upon irradiation with electron beam, X-ray or EUV light that can be used in the present invention Is a photo-initiator for photo-cationic polymerization, photo-initiator for photo-radical polymerization, photo-decoloring agent for dyes, photo-discoloring agent, or activity such as electron beam, X-ray or EUV light used in micro-resist Known compounds that generate an acid upon irradiation with light or radiation and mixtures thereof can be appropriately selected and used.

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

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

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

  Among the compounds that generate an acid upon irradiation with electron beam, X-ray or EUV light, compounds represented by the following general formula (ZI), (ZII) or (ZIII) can be exemplified.

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

X ⁻ represents a non-nucleophilic anion.

The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.

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

The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (Z1-1), (Z1-2) and (Z1-3) described later.

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

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

Compound (Z1-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.

Arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be an aryl group or a part of R ₂₀₁ to R ₂₀₃ is an aryl group and the remainder may be an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkyl or cycloalkylsulfonium compound, and an aryldialkyl or dicycloalkylsulfonium compound.

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

The alkyl group that the arylsulfonium compound has as necessary has 1 to 15 carbon atoms.
The linear or branched alkyl group is preferably, for example, methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, t-butyl group and the like.

  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 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 (Eg, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be included as a substituent. Preferred substituents are an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms, and most preferably an alkyl group having 1 to 4 carbon atoms and 1 carbon atom. It is an alkoxy group of ~ 4. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Alkyl groups R ₂₀₁ to R ₂₀₃ are aryl groups, the same cycloalkyl groups as substituents for a cycloalkyl group, an aryl group, an alkoxy group, a halogen atom, a hydroxyl group or a phenylthio group.

Examples of the non-nucleophilic anion of X ⁻ include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.
A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction, and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the resist.

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

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

  The aliphatic hydrocarbon group in the aliphatic sulfonate anion is preferably an alkyl group having 1 to 30 carbon atoms, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl. Group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, Examples thereof include an eicosyl group, and preferably a cycloalkyl group having 3 to 30 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, and a boronyl group.

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

  The alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent.

Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, and an alkylthio group.

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

  As the alkyl group, for example, preferably an alkyl group having 1 to 15 carbon atoms, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group Hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, etc. it can.

  As an alkoxy group, Preferably a C1-C5 alkoxy group, for example, a methoxy group, an ethoxy group, a propoxy group, a butoxy group etc. can be mentioned, for example.

  As the alkylthio group, for example, preferably an alkylthio group having 1 to 15 carbon atoms, such as methylthio group, ethylthio group, propylthio group, isopropylthio group, n-butylthio group, isobutylthio group, sec-butylthio group, pentylthio group, Neopentylthio, hexylthio, heptylthio, octylthio, nonylthio, decylthio, undecylthio, dodecylthio, tridecylthio, tetradecylthio, pentadecylthio, hexadecylthio, heptadecylthio, octadecylthio, nonadecylthio Group, eicosylthio group and the like. The alkyl group, alkoxy group, and alkylthio group may be further substituted with a halogen atom (preferably a fluorine atom).

  Examples of the aliphatic hydrocarbon group in the aliphatic carboxylate anion include those similar to the aliphatic hydrocarbon group in the aliphatic sulfonate anion.

  Examples of the aromatic group in the aromatic carboxylate anion include the same aromatic 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.

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

  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. These alkyl groups may have a substituent, and examples of the substituent include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, and the like, which are substituted with a fluorine atom. Alkyl groups are preferred.

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

As the non-nucleophilic anion of X ⁻ , an aliphatic sulfonate anion substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group substituted with a fluorine atom A bis (alkylsulfonyl) imide anion and a tris (alkylsulfonyl) methide anion in which the alkyl group is substituted with a fluorine atom are preferred. The non-nucleophilic anion of X ⁻ is more preferably a fluorine-substituted aliphatic sulfonate anion having 4 to 8 carbon atoms, particularly preferably a nonafluorobutane sulfonate anion or a perfluorooctane sulfonate anion.

  Next, the compound (Z1-2) will be described.

Compound (Z1-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

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

R _{201 to} R ₂₀₃ are each independently preferably an aliphatic hydrocarbon group, more preferably a linear, branched, cyclic 2-oxoalkyl group or alkoxycarbonylmethyl group, most preferably a linear, branched 2- An oxoalkyl group;

The aliphatic hydrocarbon group as R _{201 to} R ₂₀₃ may be a linear or branched alkyl group or a cycloalkyl group, and preferably a linear or branched alkyl group having 1 to 10 carbon atoms ( Examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group) and a cycloalkyl group having 3 to 10 carbon atoms (a cyclopentyl group, a cyclohexyl group, and a norbornyl group). As the aliphatic hydrocarbon group, a 2-oxoalkyl group and an alkoxycarbonylmethyl group are more preferable.

  The 2-oxoalkyl group may be linear, branched or cyclic, and preferably includes a group having> C = O at the 2-position of the above alkyl group or cycloalkyl group.

  The alkoxy group in the alkoxycarbonylmethyl group is preferably an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, butyl group, pentyl group).

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

Two members out of R _{201 to} R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

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

R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.

R _6c and R _7c represent a hydrogen atom, an alkyl group, or a cycloalkyl group.

R _x and R _y each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

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

Zc ⁻ represents a non-nucleophilic anion and is the same as the non-nucleophilic anion of X ^{− in} formula (ZI).

The alkyl group as R _{1c to} R _{5c may} be either linear or branched, for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably a straight chain having 1 to 12 carbon atoms. Examples thereof include a chain or branched alkyl group (for example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group).

Examples of the cycloalkyl group as R _{1c to} R _5c include a cycloalkyl group having 3 to 20 carbon atoms, preferably a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group and a cyclohexyl group). .

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

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

Examples of the alkyl group and cycloalkyl group as R _x and R _y include the same as the alkyl group and cycloalkyl group as R _{1c to} R _5c , and a 2-oxoalkyl group and an alkoxycarbonylmethyl group are more preferable. preferable.

Examples of the 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _5c .

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

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

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

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

Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.

The alkyl group represented by R _{204 to} R ₂₀₇ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group). Butyl group, pentyl group).

Cycloalkyl groups R ₂₀₄ to R ₂₀₇ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).

Aryl group R ₂₀₄ to R _207, an alkyl group, a cycloalkyl group may have a substituent, an aryl group of R ₂₀₄ to R _207, an alkyl group, substituent that the cycloalkyl group have As, for example, an alkyl group (for example, carbon number 1-15), a cycloalkyl group (for example, carbon number 3-15), an aryl group (for example, carbon number 6-15), an alkoxy group (for example, carbon number 1-15), A halogen atom, a hydroxyl group, a phenylthio group, etc. can be mentioned.

X ⁻ represents a non-nucleophilic anion and is the same as the non-nucleophilic anion of X ^{− in} formula (ZI).

  Further, among the other compounds that are decomposed by irradiation with electron beam, X-ray or EUV light used in the present invention, those which are particularly effectively used are represented by the following formulas (ZIV) to (ZVII). What is represented.

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

R ₂₀₆ represents an alkyl group, a cycloalkyl group or an aryl group.

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

  R represents an alkyl group, a cycloalkyl group, or an aryl group.

_R207 represents an electron-withdrawing group, and preferably represents a cyano group or a fluoroalkyl group.

R ₂₀₈ represents an alkyl group, a cycloalkyl group, or an aryl group.

  Among the compounds that generate an acid upon irradiation with electron beam, X-ray or EUV light, compounds represented by general formulas (ZI) to (ZIII) are more preferable.

Of the compounds that generate an acid upon irradiation with electron beam, X-ray or EUV light, more preferred is a sulfonium salt represented by the general formula (ZI), particularly preferred is a sulfonium salt having a carbonyl group, most preferred. is a compound or a compound represented by the general formula (Z1-3) with either the 2-oxoalkyl group R ₂₀₁ to R ₂₀₃ in the compound (Z1-2). The sensitivity is particularly improved by using a compound having a carbonyl group.

  Among the compounds that generate an acid upon irradiation with electron beam, X-ray or EUV light, examples of particularly preferable compounds are listed below.

  The addition amount of the acid generator is usually 2 to 25% by mass, preferably 4 to 20% by mass, more preferably 6 to 20% by mass, and particularly preferably 6 to 15% by mass with respect to the total solid content of the resist composition. %.

[3] Polyhydroxy compound The resin (A) used in the present invention is a cross-linking in which a polyhydroxy compound is added in the synthesis stage to adjust the alkali dissolution rate and improve the heat resistance, and the polymer main chain is linked with a polyfunctional acetal group. Sites may be introduced.

  The addition amount of the polyhydroxy compound is 0.01 to 10 mol%, preferably 0.05 to 8 mol%, more preferably 0.1 to 5 mol%, based on the number of hydroxyl groups in the resin.

Examples of the polyhydroxy compound include those having 2 to 6 phenolic hydroxyl groups or alcoholic hydroxyl groups, preferably 2 to 4 hydroxyl groups, more preferably 2 or 3 hydroxyl groups. is there.
Specific examples are shown below, but the present invention is not limited thereto.

[4] (C) Fluorine-based and / or silicon-based surfactant The positive resist composition of the present invention further comprises (C) a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant and silicon-based interface). It is preferable to contain any one or two or more of activators and surfactants containing both fluorine atoms and silicon atoms.

  When the positive resist composition of the present invention contains the above-mentioned (C) surfactant, a resist having good sensitivity and resolution and less adhesion and development defects when using an exposure light source of 250 nm or less, particularly 220 nm or less. A pattern can be given.

  As these (C) surfactants, for example, JP-A 62-36663, JP-A 61-226746, JP-A 61-226745, JP-A 62-170950, JP No. 63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A 2002-277862, US Pat. No. 5,405,720 , No. 5,360,692, No. 5,529,881, No. 5,296,330, No. 5,436,098, No. 5,576,143, No. 5,294,511, No. 5,824,451 The following commercially available surfactants can also be used as they are.

  Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

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

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

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

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

[5] (D) Basic compound The positive resist composition of the present invention preferably contains (D) a basic compound in order to reduce a change in performance over time from exposure to heating.

  Preferable structures include structures represented by the following formulas (A) to (E).

In formulas (A) to (E), R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or 6 to 6 carbon atoms. 20 aryl groups, wherein R ²⁵⁰ and R ²⁵¹ may combine with each other to form a ring. Examples of the alkyl group and cycloalkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, an aminocycloalkyl group having 3 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, and a 3 to 20 carbon atom. A hydroxycycloalkyl group is preferred.

  These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.

R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represent an alkyl group or cycloalkyl group having 1 to 6 carbon atoms.

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

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

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

[6] 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.

  In the present invention, the organic solvent may be used alone or in combination, but it is preferable to use a mixed solvent in which a solvent containing a hydroxyl group in the structure and a solvent not containing a hydroxyl group are mixed. . Thereby, the generation of particles during storage of the resist solution can be reduced.

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

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

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

  In the manufacture of precision integrated circuit elements, the pattern forming process on the resist film is carried out by applying the positive resist composition of the present invention on a substrate (eg, a transparent substrate such as a silicon / silicon dioxide covering, a glass substrate, an ITO substrate). A good resist pattern can be formed by applying an object, drying, forming a resist film, and then irradiating with electron beam, X-ray or EUV light, and preferably heating, developing, rinsing and drying. it can.

  The film thickness of the resist film formed by applying and drying the positive resist composition of the present invention on a substrate is preferably 50 to 200 nm. By setting the thickness of the resist film to 50 to 200 nm, it is possible to improve the dry etching resistance and the pattern profile and increase the transmittance of the resist film.

  The film thickness of the resist film can be adjusted by the solid content concentration excluding the solvent of the composition, the preferable solid content concentration is 5 to 18% by mass, the more preferable solid content concentration is 7 to 15% by mass, and the particularly preferable solid content is The partial concentration is 9-14% by mass.

  Examples of the alkaline developer of the positive resist composition of the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, ethylamine, and n-propylamine. Primary amines, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, An aqueous solution of alkalis such as quaternary ammonium salts such as tetraethylammonium hydroxide and choline, cyclic amines such as pyrrole and piperidine, and the like can be used. Furthermore, an appropriate amount of an alcohol such as isopropyl alcohol or a nonionic surfactant may be added to the alkaline aqueous solution.

  Among these alkaline developers, quaternary ammonium salts are preferable, and tetramethylammonium hydroxide and an aqueous solution of choline are more preferable.

  The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass, and the pH of the alkali developer is usually from 10.0 to 15.0.

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

1. Synthetic Examples of Constituent Materials (i) Synthetic Examples of Resin Synthesis 1: Synthetic Examples of Polymer (P-1) Poly (p-hydroxystyrene-co-pt-butyl acrylate) (Copolymer composition molar ratio 90:10) 20 g and 3.6 g of benzyl vinyl ether were added to tetrahydrofuran (TH
F) It melt | dissolved in 100 ml, 0.01 g of p-toluenesulfonic acid was added to this, and it was made to react at room temperature for 18 hours. The reaction solution was added dropwise to 5 L of distilled water while stirring, and the precipitated powder was filtered and dried to obtain a polymer (P-1). The weight average molecular weight of this polymer was 9600.
Other resins were synthesized in the same manner.

(Ii) Synthesis of acid generator The acid generators used in the examples of the present invention were all synthesized by a known synthesis method.

[Example 1]
(I) Preparation and coating of positive resist (component A1): Resin (P-1) Composition ratio 69/21/10 0.52 g
(A2 component): Resin (P-1) Composition ratio 51/39/10 0.40 g
(Component B): Acid generator z5 0.08 g
Is dissolved in 8.5 g of propylene glycol monomethyl ether acetate, and 0.003 g of E-1 (see below) as a nitrogen-containing basic compound is dissolved in 7.0 g of propylene glycol monomethyl ether acetate and 1.5 g of propylene glycol monomethyl ether. Furthermore, 0.001 g of MegaFac F176 (Dainippon Ink Chemical Co., Ltd., hereinafter abbreviated as W-1) was added and dissolved as a surfactant, and the resulting solution was precisely filtered with a membrane filter having a pore size of 0.1 μm. Filtration gave a resist solution. This resist solution was applied onto a 6-inch silicon wafer using a spin coater Mark8 manufactured by Tokyo Electron, and baked at 110 ° C. for 90 seconds to obtain a uniform film having a thickness of 0.30 μm. The composition ratio is a molar ratio.

(Ii) Production and Evaluation of Positive Resist Pattern This resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750, acceleration voltage 50 KeV manufactured by Hitachi, Ltd.). After irradiation, the substrate 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-4300, manufactured by Hitachi, Ltd.). Sensitivity was defined as the minimum irradiation energy when resolving a 0.15 μm line (line: space = 1: 1).
[Resolution]
The resolving power was defined as the limiting resolving power (line and space were separated and resolving) at the irradiation dose showing the above sensitivity.
[Pattern shape]
Using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.), observe the cross-sectional shape of the 0.15 μm line pattern at the irradiation dose showing the above sensitivity, and perform a three-step evaluation of rectangular, slightly tapered, and tapered. It was.
[Line edge roughness]
The line width was measured at any 30 points in the length direction of 50 μm of the 0.15 μm line pattern at the irradiation dose showing the above sensitivity, and the variation was evaluated by 3σ.

(Iii) Evaluation Results The results of Example 1 were very good with a sensitivity of 5.5 μC / cm ² , a resolving power of 0.09 μm, a pattern shape of a rectangle, and line edge roughness of 6.0 nm.

[Examples 2 to 8]
Using the compounds shown in Table 1, resist preparation / coating and electron beam exposure evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Comparative Examples 1 and 2]
(A1 component): Resin (P-1) Composition ratio 69/21/10 0.52 g
(A2 component): Resin (P-1) Composition ratio 51/39/10 0.40 g
Instead of 0.92 g of resin (P-1: composition ratio 60/30/10) (Comparative Example 1) or 0.92 g of resin (P-13: composition ratio 87/13) (Comparative Example 2) was used. Except for the above, resist preparation / coating and electron beam exposure evaluation were carried out in the same manner as in Example 1.

Other compounds used in Examples and Comparative Examples are shown below.
[Acid generator]
Corresponds to those exemplified above.

[Nitrogen-containing basic compound]
E-1: Tri-n-hexylamine E-2: 2,4,6-triphenylimidazole E-3: Tetra- (n-butyl) ammonium hydroxide [Surfactant]
W-1: Fluorosurfactant, MegaFuck F-176
(Dainippon Ink Chemical Co., Ltd.)
W-2: Fluorine / silicone surfactant, MegaFac R08
(Dainippon Ink Chemical Co., Ltd.)

The evaluation results are shown in Table 1. In addition, the numerical value in () of Table 1 represents the mass% in resist solid content.

From Table 1, the positive resist composition of the present invention has a higher sensitivity and higher resolution with respect to pattern formation by electron beam irradiation than the composition of the comparative example, and is excellent in pattern shape and line edge roughness. I understand that.

<Evaluation by EUV exposure>
[Examples 9 to 10 and Comparative Examples 3 to 4]
A resist film was obtained in the same manner as in Example 1 using the resist compositions in Examples 1 and 2 and Comparative Examples 1 and 2. However, the resist film thickness was 0.15 μm. The obtained resist film was subjected to surface exposure using EUV light (wavelength 13 nm) while changing the exposure amount by 0.5 mJ in the range of 0 to 5.0 mJ, and further baked at 110 ° C. for 90 seconds. Thereafter, using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, the dissolution rate at each exposure amount was measured to determine the sensitivity. The cases where the resist compositions of Examples 1 and 2 were used were designated as Examples 9 and 10, respectively, and the cases where the resist compositions of Comparative Examples 1 and 2 were used were designated as Comparative Examples 3 and 4, respectively.

  Next, a sample irradiated with EUV light having an exposure amount equivalent to 1/2 of the sensitivity obtained in the above experiment was prepared, and the resist film surface after 60 seconds development with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution Were observed with an AFM (atomic force microscope). The results are shown in Table 2. A indicates good, B indicates slightly good, and C indicates that the roughness is large and poor.

  From Table 2, it can be seen that the positive resist composition of the present invention has a smaller surface roughness and is superior to the composition of the comparative example in the property evaluation by irradiation with EUV light.

Claims (6)

(A) at least two resins whose solubility in an alkaline developer is increased by the action of an acid; and
(B) A resist composition containing a compound that generates an acid upon irradiation with an electron beam, X-ray or EUV light, wherein the two types of the resins have the same repeating unit structure, and the general formula ( An electron beam having a repeating unit represented by A1) and a repeating unit represented by the general formula (A2), wherein the content of the repeating unit represented by the general formula (A2) is different; X A positive resist composition for wire or EUV.
In general formulas (A1) and (A2),
Z represents a hydroxyl group, a halogen atom, a cyano group, a nitro group, an acyl group or an acyloxy group.
A ₁ represents a group containing a cyclic carbon structure and decomposing by the action of an acid.
m and n each independently represent 0-4. The repeating unit represented by the general formula (A2) in at least one of the two types of resins (A) is at least one of the group represented by the following general formula (X1) and the group represented by the general formula (X2). The positive resist composition for electron beam, X-ray or EUV according to claim 1, wherein
In formulas (X1) and (X2),
R ₁ and R ₂ each independently represents a hydrogen atom or an alkyl group.
R ₃ and R ₄ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
m represents an integer of 0 to 20.
W represents a divalent linking group.
Y represents —O—, —OCO—, —COO—, —NHCO—, —CONH—, —S—, —SO ₂ —, or —SO ₃ —.
Z _a represents a group having a cycloalkyl group or a group having an aryl group.   The positive resist composition according to claim 1 or 2, wherein the content of the repeating unit represented by the general formula (A2) is different by 5 to 50 mol% for the two types of resins (A). Item 3. The positive resist composition for electron beam, X-ray or EUV according to item 1 or 2.   The content of the compound (B) that generates an acid upon irradiation with electron beam, X-ray or EUV light is 6 to 20% by mass based on the total solid content of the resist composition. The positive resist composition for electron beam, X-ray or EUV described in any one.   Compound (B) that generates acid upon irradiation with electron beam, X-ray or EUV light, compound that generates sulfonic acid upon irradiation with electron beam, X-ray or EUV light, and irradiation with electron beam, X-ray or EUV light The positive resist composition for electron beam, X-ray or EUV according to any one of claims 1 to 4, comprising a compound capable of generating a carboxylic acid.   A pattern forming method comprising developing the positive resist composition according to claim 1 by irradiating the positive resist composition with an electron beam, an X-ray or EUV light.