JP2003177538A - Positive resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition which prevents falling of a pattern and ensures improved edge roughness, density dependence and surface roughness in etching. <P>SOLUTION: The positive resist composition comprises a resin containing a repeating unit having a dihydroxy- or trihydroxyadamantyl group and a repeating unit having an acid-decomposable alicyclic group at a specified composition molar ratio and capable of increasing the velocity of dissolution in an alkali developer by the action of an acid and a compound capable of generating an acid upon irradiation with an actinic ray or a radiation. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive resist composition used in an ultra-microlithography process such as production of an ultra-LSI or a high-capacity microchip and other photofabrication processes.

[0002]

2. Description of the Related Art In recent years, the degree of integration of integrated circuits has increased, and it has become necessary to process ultrafine patterns having a line width of less than half a micron in the manufacture of semiconductor substrates such as VLSI. Has become. In order to meet the need, the wavelength used in the exposure apparatus used for photolithography is becoming shorter and shorter, and now it is considered to use excimer laser light (XeCl, KrF, ArF, etc.) having a short wavelength even among deep ultraviolet rays. Is getting up.
A chemically amplified resist is used as a pattern for lithography in this wavelength region.

Generally, chemically amplified resists can be roughly classified into three types, commonly called two-component type, 2.5-component type and three-component type. The two-component system combines a compound that generates an acid by photolysis (hereinafter referred to as a photoacid generator) and a binder resin. The binder resin is a resin having in its molecule a group (also referred to as an acid-decomposable group) that decomposes by the action of an acid to increase the solubility of the resin in an alkaline developer. The 2.5-component system further contains a low-molecular compound having an acid-decomposable group in such a 2-component system. The three-component system contains a photo-acid generator, an alkali-soluble resin and the above-mentioned low molecular weight compound.

The above chemically amplified resist is suitable as a photoresist for irradiation with ultraviolet rays or deep ultraviolet rays, but among them, it is necessary to meet the required characteristics in use. As a photoresist composition for an ArF light source, a resin in which an alicyclic hydrocarbon site is introduced for the purpose of imparting dry etching resistance has been proposed, but the system is extremely hydrophobic as an adverse effect of introducing the alicyclic hydrocarbon site. Therefore, it is difficult to develop with an aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH), which has been widely used as a resist developing solution in the related art, and the resist peels off from the substrate during development. Can be seen. In order to deal with such hydrophobicization of the resist, measures such as mixing an organic solvent such as isopropyl alcohol into the developing solution have been studied, and although some results have been seen, the concern about swelling of the resist film and the process become complicated. It cannot be said that the problem has been solved. In the resist improvement approach, many measures have been taken to supplement various hydrophobic alicyclic hydrocarbon moieties by introducing hydrophilic groups.

On the other hand, JP-A-11-109632 describes the use of a resin containing a polar group-containing alicyclic functional group and an acid-decomposable group in a radiation-sensitive material. Further, Japanese Patent No. 3042618 describes a photoresist composition containing a polymer obtained by copolymerizing a (meth) acrylate derivative having a lactone structure with another polymerizable compound.

As described above, the resin containing an acid-decomposable group used in a photoresist for exposure to deep ultraviolet rays generally contains an aliphatic cyclic hydrocarbon group in the molecule at the same time. For this reason, the resin becomes hydrophobic and there is a problem caused by it. Various means for improving it have been studied, but the above-mentioned technique is still insufficient in many points, and improvement is desired.

Further, Japanese Patent Laid-Open No. 2001-109154 discloses a positive type photo-resist having a high sensitivity and a high resolution by a copolymer resin of an alicyclic lactone monomer and a monohydroxyadamantane monomer and having an improved edge roughness of a pattern. Although a resist composition is described, it has not been sufficiently improved with respect to the problem of pattern collapse and surface roughness during etching. Here, “pattern collapse” means that the pattern collapses at the time of forming the line pattern so as to be broken near the interface of the substrate.

Further, JP-A-2000-338674 and JP-A-2001-1883836 describe resist compositions containing a copolymer resin of a dihydroxyadamantane monomer and an acid-decomposed adamantane monomer. Still, it was not sufficiently improved in terms of collapse, surface roughness during etching, edge roughness, and dependency of density.

[0009]

Therefore, the object of the present invention is that it can be suitably used in an ultra-microlithography process such as the production of an ultra-LSI or a high-capacity microchip and other photofabrication processes.
It is intended to provide a positive resist composition in which pattern collapse is prevented, edge roughness, sparse / dense dependency, and surface roughness during etching are improved.

[0010]

Means for Solving the Problems The inventors of the present invention have made extensive studies as to the constituent material of a positive-type chemically amplified resist composition, and as a result, by using an acid-decomposable resin containing a specific repeating unit in a specific ratio, The present invention has been accomplished by knowing that the object of the present invention can be achieved. That is, the above object is achieved by the following configurations.

(1) (A) It contains at least a repeating unit A1 having a dihydroxyadamantyl group or a trihydroxyadamantyl group and a repeating unit A2 having an acid-decomposable alicyclic group as constitutional units, and is alkali-developed by the action of an acid. Resins that increase the rate of dissolution in liquid,
And (B) a positive resist composition containing a compound capable of generating an acid upon irradiation with actinic rays or radiation,
The composition molar ratio A1 / A2 of the repeating unit A1 and the repeating unit A2 in the resin (A) is 0.15 or more and 1.0 or less, and the total of the repeating unit A1 and the repeating unit A2 in the resin (A). Content is 40-70 mol%, The positive resist composition characterized by the above-mentioned. (2) The composition according to (1) above, wherein A1 / A2 is 0.35 or more and 1.0 or less. (3) The repeating unit A1 having a dihydroxyadamantyl group or a trihydroxyadamantyl group is a repeating unit represented by the following general formula (I) (1)
Alternatively, the composition according to (2).

[Chemical 4] In the general formula (I), R ₁ is a hydrogen atom, an alkyl group,
It represents a halogen atom or a cyano group, and R ₂ represents a hydrogen atom or a hydroxyl group. (4) The repeating unit A2 having an acid-decomposable alicyclic group is
The composition according to any one of (1) to (3) above, which is selected from the group of repeating units having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI). .

[Chemical 5] (In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z represents an alicyclic hydrocarbon group together with a carbon atom. Represents an atomic group necessary to form R _12.
To R ₁₆ each independently represent a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R _{12 to} R ₁₄ or R _15; ,
One of R ₁₆ represents an alicyclic hydrocarbon group. R ₁₇ ~ R ₂₁
Each independently represents a hydrogen atom, a straight-chain or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group,
However, at least one of R _{17 to} R ₂₁ represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ has 1 to 1 carbon atoms.
Represents four linear or branched alkyl groups or alicyclic hydrocarbon groups. R _{22 to} R ₂₅ each independently have 1 to 1 carbon atoms.
It represents four linear or branched alkyl groups or alicyclic hydrocarbon groups, provided that at least one of R _{22 to} R ₂₅ represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may combine with each other to form a ring. (5) The composition according to any one of (1) to (4) above, wherein the resin (A) further contains an alicyclic lactone repeating unit A3 as a constituent unit. (6) The composition according to (5) above, wherein the alicyclic lactone repeating unit A3 is a repeating unit having a group represented by any one of the following general formulas (V-1) to (V-4).

[Chemical 6] In the general formulas (V-1) to (V-4), R _{1b to} R _1b
5b's each independently represent hydrogen or an alkyl group, cycloalkyl group or alkenyl group which may have a substituent.
Two of R _{1b to} R _5b may combine with each other to form a ring.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The components used in the present invention will be described in detail below. [1] (A) A resin whose dissolution rate in an alkali developing solution is increased by the action of an acid (also referred to as “acid-decomposable resin”).

In the present invention, the repeating unit A1 having a dihydroxyadamantyl group or a trihydroxyadamantyl group is preferably a repeating unit represented by the above general formula (I).

In the general formula (I), the alkyl group represented by R ₁ may be a linear or branched alkyl group, which may have a substituent. The linear or branched alkyl group is preferably a linear or branched alkyl group having 1 to 12 carbon atoms, and more preferably a linear or branched alkyl group having 1 to 10 carbon atoms. , And more preferably methyl group, ethyl group, propyl group, isopropyl group, n-
A butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group and a decyl group.

Further, in the general formula (I), examples of the halogen atom represented by R ₁ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

The acid-decomposable alicyclic group in the present invention is a structural unit for protecting an alkali-soluble group with a residue capable of leaving under acidic conditions, and the protecting group residue after deprotection has an alicyclic structure. Are included. Examples of the alkali-soluble group include carboxylic acid, sulfonic acid, sulfonamide, N-sulfonylimide, disulfonylimide and the like, and a carboxyl group is particularly preferable from the viewpoint of transmittance and exposure margin. Examples of the alicyclic group include the cyclic hydrocarbon structure described below.

In the present invention, the repeating unit A2 having an acid-decomposable alicyclic group is preferably the above general formula (pI) to
It is selected from the group of repeating units having a partial structure containing an alicyclic hydrocarbon represented by general formula (pVI).

In the general formulas (pI) to (pVI), R
The alkyl group in _{12 to} R ₂₅ represents a linear or branched alkyl group having 1 to 4 carbon atoms, which may be substituted or unsubstituted. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group,
Examples thereof include sec-butyl group and t-butyl group. Further, the further substituent of the above alkyl group has 1 carbon atom
To 4 alkoxy groups, halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl group, acyloxy group, cyano group, hydroxyl group, carboxy group, alkoxycarbonyl group, nitro group and the like.

The alicyclic hydrocarbon group for R _{11 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples thereof include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6 to 30, and particularly preferably 7 to 25. These alicyclic hydrocarbon groups may have a substituent. Below, the structural example of an alicyclic part is shown among alicyclic hydrocarbon groups.

[0020]

[Chemical 7]

[0021]

[Chemical 8]

[0022]

[Chemical 9]

In the present invention, the alicyclic moiety is preferably adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclohexyl group. , A cycloheptyl group, a cyclooctyl group,
Examples thereof include a cyclodecanyl group and a cyclododecanyl group. More preferred are an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.

Examples of the substituent of these alicyclic hydrocarbon groups include an alkyl group, a substituted 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 and a butyl group, more preferably a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group and an isopropyl group. Represent Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as methoxy group, ethoxy group, propoxy group and butoxy group.

In the above resins, the general formulas (pI) to (pV)
The structure represented by I) can be used for protection of alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field. Specific examples thereof include carboxylic acid, sulfonic acid, sulfonamide, N-sulfonylimide, disulfonylimide and the like, but a carboxyl group is particularly preferable from the viewpoint of transmittance and exposure margin. General formulas (pI) to (p in the above resin
The alkali-soluble group protected by the structure represented by VI) is preferably the following general formulas (pVII) to (pX).
The group represented by I) may be mentioned.

[0026]

[Chemical 10]

Here, R _{11 to} R ₂₅ and Z are the same as defined above. In the above resin, the repeating unit having an alkali-soluble group protected by the structures represented by the general formulas (pI) to (pVI) is preferably a repeating unit represented by the following general formula (pA).

[0028]

[Chemical 11]

Here, R represents a hydrogen atom, a halogen atom or a substituted or unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different. A represents a single bond or a divalent linking group. As the divalent linking group, an alkylene group,
It represents a single group or a combination of two or more groups selected from the group consisting of a substituted alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, and a urea group. _Ra
Represents any group of the above formulas (pI) to (pVI).

Specific examples of the monomer corresponding to the repeating unit represented by the general formula (pA) are shown below.

[0031]

[Chemical 12]

[0032]

[Chemical 13]

[0033]

[Chemical 14]

[0034]

[Chemical 15]

[0035]

[Chemical 16]

[0036]

[Chemical 17]

In the acid-decomposable resin (A) of the present invention, the composition molar ratio A1 / A2 of the repeating unit A1 having a dihydroxyadamantyl group or trihydroxyadamantyl group and the repeating unit A2 having an acid-decomposable alicyclic group is 0. .15 or more and 1.0 or less, preferably 0.35 or more 1.
0 or less, and the total content of A1 and A2 is 40 to
It should be 70 mol%. The composition ratio A1 / A2 is 0.
If it is less than 15, the pattern collapse prevention property and the surface roughness prevention property during etching deteriorate. In addition, the pattern collapse prevention property and the surface roughness prevention property during etching are further improved,
Further, A1 / A2 is preferably 0.35 or more from the viewpoint of satisfying the edge roughness and the density dependency. On the other hand, when it exceeds 1.0, the pattern collapse prevention property deteriorates, which is not preferable. Further, if the total content of A1 and A2 is less than 40 mol%, the resolution and the edge roughness are deteriorated to 70 mol%.
Even if it exceeds the range, the density dependency, the surface roughness prevention property during etching, and the pattern collapse prevention property deteriorate, which is not preferable. More preferably, the ratio of A1 / A2 is 0.4
It is above 0.8 and below. On the other hand, the total content of A1 and A2 is more preferably 45 to 65 mol%. Also,
More preferably, A1 / A2 is 0.4 or more and 0.8 or less, and the total content of A1 and A2 is 45 to 65 mol%.

The acid-decomposable resin (A) of the present invention preferably further contains an alicyclic lactone repeating unit A3 as a structural unit in the repeating units A1 and A2. As the alicyclic lactone repeating unit A3, general formula (V-1) to
Examples thereof include a repeating unit having a group represented by any of (V-4) and a repeating unit having a group represented by the general formula (VI). The alicyclic lactone repeating unit is
It is preferable from the viewpoint of pattern collapse and surface roughness of etching as compared with a repeating unit having a general lactone residue. Content of alicyclic lactone repeating unit is 5 to 65 m
ol% is preferable, more preferably 10 to 60 mol
%, And more preferably 15 to 55 mol%. Further, among the alicyclic lactone repeating units, general formula (V-1) to
A repeating unit having a group represented by any of (V-4) is preferable from the viewpoint of pattern collapse.

In the general formulas (V-1) to (V-4),
R _{1b to} R _5b each independently represent a hydrogen atom or an optionally substituted alkyl group, cycloalkyl group or alkenyl group. Two of R _{1b to} R _5b may combine with each other to form a ring.

In the general formulas (V-1) to (V-4),
Examples of the alkyl group for R _{1b to} R _5b include linear and branched alkyl groups, which may have a substituent. The linear or branched alkyl group has 1 to 1 carbon atoms.
12 straight chain or branched alkyl groups are preferred,
More preferably, it is a linear or branched alkyl group having 1 to 10 carbon atoms, and even more preferably, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t. -Butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group,
It is a decyl group.

The cycloalkyl group in R _{1b to} R _5b is preferably a cycloalkyl group having 3 to 8 carbon atoms such as cyclopropyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. The alkenyl group in R _{1b to} R _5b is preferably an alkenyl group having a carbon number of 2 to 6, such as a vinyl group, a propenyl group, a butenyl group and a hexenyl group. Examples of the ring formed by combining two members out of R _{1b to} R _5b include a 3- to 8-membered ring such as a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, and a cyclooctane ring. In addition, general formula (V-1)-
R _{1b to} R _5b in (V-4) may be linked to any of the carbon atoms constituting the cyclic skeleton.

Preferred substituents that the alkyl group, cycloalkyl group and alkenyl group may have are alkoxy groups having 1 to 4 carbon atoms, halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine). Atom), an acyl group having 2 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, a cyano group, a hydroxyl group, a carboxy group, an alkoxycarbonyl group having 2 to 5 carbon atoms, a nitro group and the like.

The repeating unit having a group represented by any one of the general formulas (V-1) to (V-4) is represented by the following general formula (AI).
The repeating unit represented by

[0044]

[Chemical 18]

In the general formula (AI), R _b0 represents a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group represented by R _b0 may have include those represented by the general formula (V-1) to
Examples of the preferable substituent that the alkyl group as R _1b in (V-4) may have include those exemplified above. Examples of the halogen atom of R _b0 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R
_b0 is preferably a hydrogen atom. A'represents a single bond or a divalent linking group. The divalent linking group represents an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these. B ₂ is a general formula (V-1).
~ Represents a group represented by any one of (V-4).
In A ′, examples of the combined divalent group include those represented by the following formulas.

[0046]

[Chemical 19]

In the above formula, R _ab and R _bb represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group or an alkoxy group, and they may be the same or different. The alkyl group is preferably a lower alkyl group such as methyl group, ethyl group, propyl group, isopropyl group and butyl group, and more preferably selected from methyl group, ethyl group, propyl group and isopropyl group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom, and an alkoxy group having 1 to 4 carbon atoms. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as methoxy group, ethoxy group, propoxy group and butoxy group. Examples of the halogen atom include chlorine atom, bromine atom, fluorine atom, iodine atom and the like. r
1 represents an integer of 1 to 10, preferably an integer of 1 to 4.
m represents an integer of 1 to 3, preferably 1 or 2.

Specific examples of the repeating unit represented by formula (AI) are shown below, but the contents of the present invention are not limited to these.

[0049]

[Chemical 20]

[0050]

[Chemical 21]

[0051]

[Chemical formula 22]

[0052]

[Chemical formula 23]

[0053]

[Chemical formula 24]

[0054]

[Chemical 25]

[0055]

[Chemical formula 26]

The acid-decomposable resin of the present invention may further contain a repeating unit represented by the following general formula (VI).

[0057]

[Chemical 27]

In the general formula (VI), A ₆ represents a single bond or a divalent linking group. The divalent linking group represents a single group or a combination of two or more groups selected from the group consisting of an alkylene group, a cycloalkylene group, an ether group, a thioether group, a carbonyl group and an ester group. R _6a
Represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, or a halogen atom.

In the general formula (VI), examples of the alkylene group represented by A ₆ include groups represented by the following formula. -[C (Rnf) (Rng)] r- In the above formula, Rnf and Rng are each a hydrogen atom, an alkyl group,
It represents a substituted alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, and they may be the same or different. The alkyl group is preferably a lower alkyl group such as methyl group, ethyl group, propyl group, isopropyl group and butyl group, and more preferably selected from methyl group, ethyl group, propyl group and isopropyl group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as methoxy group, ethoxy group, propoxy group and butoxy group. Examples of the halogen atom include chlorine atom, bromine atom, fluorine atom, iodine atom and the like. r is an integer of 1-10. General formula (VI)
In the above, examples of the cycloalkylene group represented by A ₆ include those having 3 to 10 carbon atoms.
Examples thereof include a cyclohexylene group and a cyclooctylene group.

The bridged alicyclic ring containing Z ₆ may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (preferably having 1 to 4 carbon atoms), an alkoxycarbonyl group (preferably having 1 to 5 carbon atoms), an acyl group (eg, formyl group, benzoyl group), an acyloxy group ( Examples thereof include a propylcarbonyloxy group, a benzoyloxy group), an alkyl group (preferably having a carbon number of 1 to 4), a carboxyl group, a hydroxyl group, an alkylsulfonylsulfamoyl group (-CONHSO ₂ CH ₃ etc.). still,
The alkyl group as a substituent may be further substituted with a hydroxyl group, a halogen atom, an alkoxy group (preferably having a carbon number of 1 to 4) or the like.

In the general formula (VI), the oxygen atom of the ester group bonded to A ₆ may be bonded at any position of the carbon atoms constituting the bridged alicyclic ring structure containing Z _6. Good.

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

[0063]

[Chemical 28]

[0064]

[Chemical 29]

The acid-decomposable resin (A) of the present invention may further contain a repeating unit having a lactone structure represented by the following general formula (IV).

[0066]

[Chemical 30]

In the general formula (IV), R1a represents a hydrogen atom or a methyl group. W ₁ represents a single bond or a divalent linking group. The divalent linking group represents a single group or a combination of two or more groups selected from the group consisting of an alkylene group, an ether group, a thioether group, a carbonyl group and an ester group. Ra ₁ , Rb ₁ , Rc ₁ , Rd ₁ and Re ₁ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
m and n each independently represent an integer of 0 to 3, and m + n is 2
The above is 6 or less.

Examples of the alkyl group having 1 to 4 carbon atoms represented by Ra _{1 to} Re ₁ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group and the like. Can be mentioned.

In the general formula (IV), examples of the alkylene group for W ₁ include groups represented by the following formula. — [C (Rf) (Rg)] r ₁ — In the above formula, Rf and Rg represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, and both may be the same or different. Good. The alkyl group is preferably a lower alkyl group such as methyl group, ethyl group, propyl group, isopropyl group and butyl group, and more preferably selected from methyl group, ethyl group, propyl group and isopropyl group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as methoxy group, ethoxy group, propoxy group and butoxy group. Examples of the halogen atom include chlorine atom, bromine atom, fluorine atom, iodine atom and the like. r ₁ is an integer of ₁ to 10.

Further substituents in the above alkyl group include a carboxyl group, an acyloxy group, a cyano group, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a substituted alkoxy group, an acetylamide group, an alkoxycarbonyl group, An acyl group can be mentioned. Examples of the alkyl group include lower alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a cyclopropyl group, a cyclobutyl group and a cyclopentyl group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. Examples of the substituent of the substituted alkoxy group include an alkoxy group and the like. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as methoxy group, ethoxy group, propoxy group and butoxy group. An acetoxy group etc. are mentioned as an acyloxy group. Examples of the halogen atom include chlorine atom, bromine atom, fluorine atom, iodine atom and the like.

Specific examples of the monomer corresponding to the repeating unit represented by the general formula (IV) are shown below, but the invention is not limited thereto.

[0072]

[Chemical 31]

[0073]

[Chemical 32]

[0074]

[Chemical 33]

In the specific example of the above general formula (IV), from the viewpoint that the exposure margin becomes better (IV-17) to
(IV-36) is preferred. Further, as the structure of the general formula (IV), a structure having an acrylate structure is preferable from the viewpoint of good edge roughness.

The acid-decomposable resin (A) of the present invention may further contain a repeating unit having a group represented by the following general formula (VII).

[0077]

[Chemical 34]

In the general formula (VII), R _3c represents a hydroxyl group,
R _2c and R _4c each independently represent a hydrogen atom or an alkyl group. The alkyl group preferably has 1 to 4 carbon atoms.

Examples of the repeating unit having a group represented by the general formula (VII) include a repeating unit represented by the following general formula (AII).

[0080]

[Chemical 35]

In formula (AII), R _1c represents a hydrogen atom or a methyl group. R _3c represents a hydroxyl group, and R _2c and R _4c each independently represent a hydrogen atom or an alkyl group. The alkyl group preferably has 1 to 4 carbon atoms.

The specific examples of the repeating units having the structure represented by formula (AII) are shown below, but the invention is not limited thereto.

[0083]

[Chemical 36]

The acid-decomposable resin which is the component (A) has, in addition to the above repeating units, dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution which is a general required property of resist. Various repeating units can be contained for the purpose of adjusting heat resistance, sensitivity and the like.

Examples of such repeating units include, but are not limited to, repeating structural units corresponding to the following monomers. This allows
Performance required of acid-decomposable resin, in particular, (1) solubility in coating solvent, (2) film-forming property (glass transition point),
Fine adjustments such as (3) alkali developability, (4) film slippage (hydrophilicity / hydrophobicity, selection of alkali-soluble groups), (5) adhesion of the unexposed area to the substrate, and (6) dry etching resistance are possible. . Examples of such monomers include acrylic acid esters, methacrylic acid esters, acrylamides,
Examples thereof include compounds having one addition-polymerizable unsaturated bond selected from methacrylamides, allyl compounds, vinyl ethers, vinyl esters and the like.

Specifically, the following monomers can be mentioned. Acrylic esters (preferably alkyl acrylates having an alkyl group having 1 to 10 carbon atoms): methyl acrylate, ethyl acrylate, propyl acrylate,
Amyl acrylate, cyclohexyl acrylate, ethylhexyl acrylate, octyl acrylate, t-octyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane Monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.

Methacrylic acid esters (preferably alkyl methacrylate having an alkyl group having 1 to 10 carbon atoms): methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate,
Cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, penta Erythritol monomethacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, etc.

Acrylamides: Acrylamide, N-
Alkyl acrylamide (Alkyl group has 1 carbon
10 to, for example, methyl group, ethyl group, propyl group, butyl group, t-butyl group, heptyl group, octyl group, cyclohexyl group, hydroxyethyl group and the like. ), N, N-dialkylacrylamide (alkyl group having 1 to 10 carbon atoms, such as methyl group, ethyl group, butyl group, isobutyl group, ethylhexyl group,
(Eg, cyclohexyl group), N-hydroxyethyl-
N-methyl acrylamide, N-2-acetamidoethyl-N-acetyl acrylamide and the like.

Methacrylamides: Methacrylamides,
N-alkylmethacrylamide (alkyl group having 1 to 10 carbon atoms, for example, methyl group, ethyl group, t-
Butyl group, ethylhexyl group, hydroxyethyl group, cyclohexyl group, etc.), N, N-dialkylmethacrylamide (alkyl groups include ethyl group, propyl group, butyl group, etc.), N-hydroxyethyl-N-
Methylmethacrylamide, etc.

Allyl compounds: Allyl esters (eg, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate), allyloxyethanol. etc.

Vinyl ethers: alkyl vinyl ethers (eg hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1
-Methyl-2,2-dimethylpropyl vinyl ether,
2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether,
Dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, etc.

Vinyl esters: vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl barrate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinyl. Acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate and the like.

Dialkyl itaconates: dimethyl itaconate, diethyl itaconate, dibutyl itaconate and the like. Dialkyl esters or monoalkyl esters of fumaric acid; dibutyl fumarate and the like.

Others Crotonic acid, itaconic acid, maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleironitrile and the like.

In addition, an addition-polymerizable unsaturated compound copolymerizable with the monomers corresponding to the above various repeating units may be copolymerized.

In the acid-decomposable resin, the molar ratio of each repeating unit depends on the dry etching resistance of the resist, suitability for a standard developing solution, substrate adhesion, resist profile, and resolution and heat resistance which are general required performances of the resist. ,
It is appropriately set to adjust the sensitivity and the like.

The content of the alicyclic lactone repeating unit A3 in the acid-decomposable resin is preferably 5 to 65 mol%, more preferably 10 to 60 mol%, and further preferably 15 to 55 mol% in all repeating units. is there. In acid-decomposable resin, repeating unit A1 (repeating unit represented by general formula (I))
The content of is preferably 5 to 30 mol% in all repeating units, more preferably 10 to 28 mol%, and further preferably 15 to 25 mol%. In the acid-decomposable resin, the content of the repeating unit A2 (repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pVI)) is 24 to 55 mol in all repeating units. %, More preferably 26 to 50 mol%, further preferably 28 to
It is 45 mol%.

The content of the repeating unit based on the monomer of the additional copolymerization component in the resin can also be appropriately set according to the desired performance of the resist. A repeating unit having a group represented by any one of (V-1) to (V-4) and the above general formula (pI) to
It is preferably 99 mol% or less based on the total total number of moles of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by (pVI) and the repeating unit represented by the general formula (I), and It is preferably 90 mol% or less, more preferably 80 mol% or less.

The acid-decomposable resin used in the present invention can be synthesized by a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer species is charged in a batch or in the middle of the reaction into a reaction vessel, and if necessary, a reaction solvent, for example, tetrahydrofuran, 1,4-dioxane, ethers such as diisopropyl ether or methyl ethyl ketone, Ketones such as methyl isobutyl ketone, ester solvents such as ethyl acetate, and further homogenized by dissolving in a solvent dissolving the composition of the present invention such as propylene glycol monomethyl ether acetate described later, nitrogen, argon, etc. If necessary, heating is performed in an inert gas atmosphere, and polymerization is initiated using a commercially available radical initiator (azo initiator, peroxide, etc.).
If desired, an initiator is added or added in portions, and after completion of the reaction, the reaction mixture is put into a solvent to recover the desired polymer by a method such as powder or solid recovery. Reaction concentration is 20% by weight
It is at least 30% by weight, preferably at least 40% by weight. Reaction temperature is 10 ° C to 150
C., preferably 30 to 120.degree. C., more preferably 50 to 100.degree.

The weight average molecular weight of the resin according to the present invention is G
The polystyrene conversion value by the PC method is preferably 1,000 to 200,000. When the weight average molecular weight is less than 1,000, heat resistance and dry etching resistance are deteriorated, which is not preferable, and when it exceeds 200,000, developability is deteriorated and film forming property is deteriorated due to extremely high viscosity. It produces less favorable results.

The degree of dispersion of the resin according to the present invention (Mw /
The Mn) is preferably in the range of 1.4 to 3.5, and 1.5
The range of -3.3 is more preferable, and the range of 1.7-2.8 is particularly preferable.

In the positive resist composition of the present invention,
The blending amount of all the resins according to the present invention in the entire composition is
The total solid content of the resist is preferably 40 to 99.99% by weight, more preferably 50 to 99.97% by weight.

[2] (B) Compound that Generates Acid upon Irradiation with Actinic Rays or Radiation (Photoacid Generator) The photoacid generator used in the present invention is a compound that generates an acid upon irradiation with actinic rays or radiation. Is.

Examples of the photo-acid generator used in the present invention include:
Photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photobleaching agents for dyes, photochromic agents, or known light used for micro resists (400 to 200 n
m ultraviolet rays, far ultraviolet rays, particularly preferably g rays, h rays,
Compounds that generate an acid by i-ray, KrF excimer laser light), ArF excimer laser light, electron beam, X-ray, molecular beam or ion beam, and mixtures thereof can be appropriately selected and used.

Other photoacid generators used in the present invention include, for example, diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, arsonium salts, and other onium salts,
Organic halogen compounds, organic metal / organic halides, o
Examples thereof include a photoacid generator having a nitrobenzyl-type protecting group, a compound represented by iminosulfonate and the like, which photolyzes to generate a sulfonic acid, a disulfone compound, a diazoketosulfone, a diazodisulfone compound.
Further, a group in which an acid-generating group or a compound is introduced into the main chain or side chain of a polymer can be used.

Furthermore, VNR Villai, Synthesis, (1), 1 (198
0), A. Abad et al, Tetrahedron Lett., (47) 4555 (1971),
DHR Barton et al., J. Chem. Soc., (C), 329 (1970), U.S. Pat. No. 3,779,778, European Patent 126,712 and the like which generate an acid by light can also be used.

Among the compounds which decompose to generate an acid upon irradiation with actinic rays or radiation, other photoacid generators that are particularly effectively used together will be described below. (1) An oxazole derivative represented by the following general formula (PAG1) or an S-triazine derivative represented by the general formula (PAG2) substituted with a trihalomethyl group.

[0108]

[Chemical 37]

In the formula, R ²⁰¹ is a substituted or unsubstituted aryl group or alkenyl group, R ₂₀₂ is a substituted or unsubstituted aryl group, alkenyl group, alkyl group or —C (Y) ₃
Indicate. Y represents a chlorine atom or a bromine atom. The following compounds can be specifically mentioned, but the compounds are not limited to these.

[0110]

[Chemical 38]

(2) An iodonium salt represented by the following general formula (PAG3) or a sulfonium salt represented by the following general formula (PAG4).

[0112]

[Chemical Formula 39]

Here, the formulas Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. R ²⁰³ ,
^R204 and ^R205 each independently represent a substituted or unsubstituted alkyl group or aryl group.

Z-represents a counter anion, for example, B
F ₄ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , SiF ₆ ²⁻ , Cl
Condensed polynuclear aromatic sulfonate anion such as perfluoroalkane sulfonate anion such as O ₄ ⁻ and CF ₃ SO ₃ ⁻ , pentafluorobenzene sulfonate anion, naphthalene-1-sulfonate anion, anthraquinone sulfonate anion, sulfonate group Examples thereof include dyes contained therein, but are not limited thereto.

Two of R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ and Ar ¹ and Ar ² may be bonded via a single bond or a substituent.

Specific examples include, but are not limited to, the compounds shown below.

[0117]

[Chemical 40]

[0118]

[Chemical 41]

[0119]

[Chemical 42]

[0120]

[Chemical 43]

[0121]

[Chemical 44]

[0122]

[Chemical formula 45]

[0123]

[Chemical formula 46]

[0124]

[Chemical 47]

[0125]

[Chemical 48]

[0126]

[Chemical 49]

[0127]

[Chemical 50]

[0128]

[Chemical 51]

[0129]

[Chemical 52]

[0130]

[Chemical 53]

[0131]

[Chemical 54]

In the above, Ph represents a phenyl group.
The onium salts represented by the general formulas (PAG3) and (PAG4) are known and can be synthesized by the method described in, for example, U.S. Pat. Nos. 2,807,648 and 4,247,473, and JP-A-53-101,331. .

(3) A disulfone derivative represented by the following general formula (PAG5) or an iminosulfonate derivative represented by the general formula (PAG6).

[0134]

[Chemical 55]

In the formula, Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group. R ²⁰⁶ represents a substituted or unsubstituted alkyl group or aryl group. A represents a substituted or unsubstituted alkylene group, alkenylene group, or arylene group.

Specific examples include, but are not limited to, the compounds shown below.

[0137]

[Chemical 56]

[0138]

[Chemical 57]

[0139]

[Chemical 58]

[0140]

[Chemical 59]

[0141]

[Chemical 60]

(4) A diazodisulfone derivative represented by the following general formula (PAG7).

[0143]

[Chemical formula 61]

Here, R represents a linear, branched or cyclic alkyl group or an optionally substituted aryl group. Specific examples thereof include the compounds shown below, but the invention is not limited thereto.

[0145]

[Chemical formula 62]

[0146]

[Chemical formula 63]

The addition amount of these photo-acid generators is usually in the range of 0.01 to 30% by weight, preferably 0.3 to 20% by weight, and more preferably, based on the solid content in the composition. Is used in the range of 0.5 to 10% by weight. If the addition amount of the photo-acid generator is less than 0.001% by weight, the sensitivity tends to be low, and if the addition amount is more than 30% by weight, the light absorption of the resist becomes too high, resulting in deterioration of the profile and process. (Especially bake) Margin tends to be narrow.

[3] Other Additives In the positive resist composition of the present invention, if necessary, an acid-decomposable dissolution inhibiting compound, a dye, a plasticizer, a surfactant,
A photosensitizer, an organic basic compound, a compound that promotes solubility in a developing solution, and the like can be contained.

The positive resist composition of the present invention preferably contains (C) a fluorine-based and / or silicon-based surfactant. The positive resist composition of the present invention preferably contains one or more of a fluorine-based surfactant, a silicon-based surfactant, and a surfactant containing both a fluorine atom and a silicon atom. . When the positive resist composition of the present invention contains the acid-decomposable resin and the surfactant, it is particularly effective when the line width of the pattern is narrower, and the development defect is further improved. Examples of these surfactants include JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, and JP-A-62-170950.
No. 63-34540, No. 7-230165, No. 8-62
834, JP 9-54432, JP 9-5988, US Patent 54
05720, 5360692, 5528918, 5296330,
The surfactants described in Nos. 5436098, 5576143, 5294511 and 5284451 can be mentioned, and the following commercially available surfactants can be used as they are. Examples of commercially available surfactants that can be used include Ftop EF301, EF303,
(Manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Ltd.), Megafac F171, F173, F176, F18
9, R08 (manufactured by Dainippon Ink and Chemicals, Inc.), Surflon S-382,
SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.),
Fluorosurfactants or silicon surfactants such as Troisol S-366 (manufactured by Troy Chemical Co., Ltd.) can be mentioned. Further, polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

The content of the surfactant is usually 0.001% by weight to 2% by weight, preferably 0.01% by weight to 1% by weight, based on the solid content in the composition of the present invention. These surfactants may be added alone or in some combinations.

Specific examples of the surfactant that can be used in addition to the above include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether and the like. Polyoxyethylene alkyl allyl ethers such as ethylene alkyl ethers, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostea Sorbitan monooleate, sorbitan trioleate, sorbitan tristearate and other sorbitan fatty acid esters, polyoxyethylene Nonionics such as polyoxyethylene sorbitan fatty acid esters such as rubitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Examples thereof include system surfactants. The amount of these other surfactants to be added is usually 2 parts by weight or less, preferably 1 part by weight or less, per 100 parts by weight of the solid content in the composition of the present invention.

The preferred organic basic compound (D) that can be used in the present invention is a compound that is more basic than phenol. Of these, nitrogen-containing basic compounds are preferable, and specific examples include compounds having the following structures.

[0153]

[Chemical 64]

R ²⁵⁰ , R ^251, and R ²⁵² are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aminoalkyl group having 1 to 6 carbon atoms, or a hydroxyalkyl having 1 to 6 carbon atoms. A group or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, in which R ²⁵¹ and R ²⁵² may combine with each other to form a ring.

[0155]

[Chemical 65]

(Wherein R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R
Each ²⁵⁶ independently represents an alkyl group having 1 to 6 carbon atoms. ) Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms of different chemical environments in one molecule,
Particularly preferred is a compound containing both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom, or a compound having an alkylamino group. Preferred specific examples include substituted or unsubstituted guanidine, substituted or unsubstituted aminopyridine, substituted or unsubstituted aminoalkylpyridine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted indazole, substituted or unsubstituted Pyrazole, substituted or unsubstituted pyrazine,
Substituted or unsubstituted pyrimidine, substituted or unsubstituted purine, substituted or unsubstituted imidazoline, substituted or unsubstituted pyrazoline, substituted or unsubstituted piperazine, substituted or unsubstituted aminomorpholine, substituted or unsubstituted amino An alkyl morpholine etc. are mentioned. Preferred substituents are amino groups, aminoalkyl groups, alkylamino groups, aminoaryl groups, arylamino groups, alkyl groups, alkoxy groups, acyl groups, acyloxy groups, aryl groups, aryloxy groups, nitro groups,
A hydroxyl group and a cyano group.

Preferred specific examples of the nitrogen-containing basic compound include guanidine, 1,1-dimethylguanidine, 1,
1,3,3-tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2
-Dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-
Amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, 4-aminoethylpyridine, 3-aminopyrrolidine, piperazine, N- (2-amino Ethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine, 1- (2-aminoethyl) Pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-
3-methyl-1-p-tolylpyrazole, pyrazine, 2
-(Aminomethyl) -5-methylpyrazine, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-
Aminomorpholine, N- (2-aminoethyl) morpholine, 1,5-diazabicyclo [4.3.0] nona
5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2.2.2]
Octane, 2,4,5-triphenylimidazole, N
-Methylmorpholine, N-ethylmorpholine, N-hydroxyethylmorpholine, N-benzylmorpholine, cyclohexylmorpholinoethylthiourea (CHMET
U) and other tertiary morpholine derivatives, JP-A-11-5257
Examples thereof include hindered amines described in JP-A No. 5 (for example, those described in the above-mentioned JP-A No. 2005-2000), but are not limited thereto.

A particularly preferred embodiment is 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo. [2.2.2] Octane, 4-dimethylaminopyridine, hexamethylenetetramine, 4,4-dimethylimidazoline, pyrroles, pyrazoles, imidazoles, pyridazines, pyrimidines, tertiary morpholines such as CHMETU, bis Examples thereof include hindered amines such as (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate. Among them, 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-
Diazabicyclo [5.4.0] undec-7-ene,
1,4-diazabicyclo [2.2.2] octane, 4-
Dimethylaminopyridine, hexamethylenetetramine,
CHMETU, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate is preferred.

These nitrogen-containing basic compounds may be used alone or in combination of two or more. The nitrogen-containing basic compound is used in an amount of usually 0.001 to 10% by weight, preferably 0.01 to 5% by weight, based on the total solid content of the photosensitive resin composition. If it is less than 0.001% by weight, the effect of adding the nitrogen-containing basic compound cannot be obtained. On the other hand, if it exceeds 10% by weight, the sensitivity tends to decrease and the developability of the unexposed area tends to deteriorate.

The positive resist composition of the present invention is dissolved in a solvent which dissolves each of the above components and coated on a support. As the solvent used here, 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 (PGMEA), toluene, ethyl acetate, acetic acid Butyl, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable, These solvents are used alone or as a mixture.

Of the above, preferred solvents include propylene glycol monomethyl ether acetate and 2-
Heptanone, γ-butyrolactone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, butyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate,
Ethyl ethoxypropionate, N-methylpyrrolidone,
Tetrahydrofuran can be mentioned.

The positive resist composition of the present invention is applied on a substrate to form a thin film. The thickness of this coating film is preferably 0.2 to 1.2 μm. The inorganic substrate that can be used in the present invention, a normal BareSi substrate, SO
Examples thereof include a G substrate, a substrate having an inorganic antireflection film described below, and the like. Further, in the present invention, if necessary, a commercially available inorganic or organic antireflection film can be used.

As the antireflection film, an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon and α-silicon, and an organic film type composed of a light absorbing agent and a polymer material can be used. The former requires equipment such as a vacuum vapor deposition apparatus, a CVD apparatus, and a sputtering apparatus for forming a film. Examples of the organic antireflection film include Japanese Patent Publication No. 7-69
No. 611, which comprises a condensate of a diphenylamine derivative and formaldehyde-modified melamine resin, an alkali-soluble resin, and a light absorber, and a reaction product of a maleic anhydride copolymer and a diamine-type light absorber described in US Pat. No. 5,294,680. A resin binder and a methylol melamine-based thermal cross-linking agent described in JP-A 6-118631; A compound comprising methylolmelamine and a benzophenone-based light absorber described in JP-A-8-87115, JP-A-8-1
The polyvinyl alcohol resin described in No. 79509 to which a low molecular weight light absorber is added may be used. As an organic antireflection film, DUV3 manufactured by Brewer Science Co., Ltd.
0 series, DUV-40 series, ARC25, Shipley AC-2, AC-3, AR19, AR20
Etc. can also be used.

The resist solution is applied to a substrate (eg, silicon / silicon dioxide coating) used for manufacturing precision integrated circuit devices (eg, a substrate optionally provided with the antireflection film), a spinner, and a coater. A good resist pattern can be obtained by applying a suitable coating method such as the above, exposing through a predetermined mask, baking and developing. Here, the exposure light is preferably 150
It is light having a wavelength of nm to 250 nm. Specifically, Kr
F excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157
nm), X-rays, electron beams and the like.

As the developing solution, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, etc.,
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. It is possible to use an alkaline aqueous solution of a quaternary ammonium salt, a cyclic amine such as pyrrole, or a pyrhelidine. Furthermore, alcohols and surfactants may be added in appropriate amounts to the alkaline aqueous solution before use.

[0166]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to the following examples.

Synthesis Example (1) Synthesis of Resin (1-1) 2-adamantyl-2-propyl methacrylate (repeating unit A2), norbornane lactone acrylate,
Dihydroxyadamantane methacrylate (repeating unit A1) was charged at a ratio of 50/40/10 and dissolved in methyl ethyl ketone / tetrahydrofuran = 9/1 to prepare 450 g of a solution having a solid content concentration of 22%. 10 mol% of V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to this solution, and this was added dropwise to 40 g of methyl ethyl ketone heated to 65 ° C. over 6 hours under a nitrogen atmosphere. After completion of dropping, the reaction solution was stirred for 4 hours. After the reaction was completed, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of methanol / ISO propyl alcohol = 3/1, and the precipitated white powder was filtered, and the obtained powder was reslurried with 1 L of methanol. Then, the objective Resin (1-1) was recovered. The polymer composition ratio determined from NMR was 46/42/12 (A1 / A2 = 0.26, A1 +
A2 = 58 mol%). Further, the weight average molecular weight in terms of standard polystyrene determined by GPC measurement is 131.
00 and the degree of dispersion Mw / Mn = 2.2.

Synthesis Example (2) Synthesis of Resin (1-2) 2-Adamantyl-2-propyl methacrylate, norbornane lactone acrylate and dihydroxyadamantan methacrylate were charged at a ratio of 50/40/10, and methyl ethyl ketone / tetrahydrofuran = 9/1.
450 g of a solution having a solid content of 22% was prepared. 10 mol% of V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to this solution, and this was added dropwise to 40 g of methyl ethyl ketone heated to 65 ° C. over 6 hours under a nitrogen atmosphere. After the dropping is completed,
The reaction was stirred for 4 hours. After the completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a hexane solvent, the precipitated white powder was filtered, dissolved again in tetrahydrofuran, and reprecipitated in 5 L of hexane to obtain the target product. Resin (1
-2) was recovered. The polymer composition ratio determined from NMR was 46/42/12 (A1 / A2 = 0.26, A1 + A2
= 58 mol%). Further, the weight average molecular weight in terms of standard polystyrene determined by GPC measurement is 1020.
The degree of dispersion was Mw / Mn = 3.5.

Synthesis Example (3) Synthesis of Resin (1-3) 2-adamantyl-2-propyl methacrylate, norbornane lactone acrylate, dihydroxyadamantan methacrylate were charged at a ratio of 50/40/10, and methyl ethyl ketone / tetrahydrofuran = 9/1.
450 g of a solution having a solid content of 22% was prepared. 10 mol% of V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to this solution, and this was added dropwise to 40 g of methyl ethyl ketone heated to 65 ° C. over 6 hours under a nitrogen atmosphere. After the dropping is completed,
The reaction was stirred for 4 hours. After the reaction was completed, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of hexane / ethyl acetate = 85/15, and the white powder precipitated was collected by filtration, dissolved again in tetrahydrofuran, and further mixed with hexane / hexane. The resin (1-3), which was a target substance, was recovered by reprecipitation in 5 L of a mixed solvent of ethyl acetate = 85/15. The polymer composition ratio determined from NMR was 45/43/12 (A1 / A2 = 0.27,
A1 + A2 = 57 mol%). Further, the weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 11,300, and the degree of dispersion Mw / Mn = 2.9.

Synthesis Example (4) Synthesis of Resin (1-4) The resin (1-1) obtained in Synthesis Example (1) was subjected to silica gel column chromatography using a hexane / acetone mixed solvent (99/1 to 50/50). Column fractionation was carried out. The polymer composition ratio determined from NMR was 45/43/12 (A1 / A
2 = 0.27, A1 + A2 = 57 mol%). Moreover, the weight average molecular weight in terms of standard polystyrene determined by GPC measurement is 11,700, and the dispersity Mw / Mn = 1.4.
Met.

Resins (2) to (12) having the composition ratios and molecular weights shown in the table below were synthesized by the same operation as in the above synthesis example. (Each repeating unit in the table is shown in the order from the left of the displayed structural formula.)

[0172]

[Table 1]

[0173]

[Table 2]

The structures of the above resins (1) to (12) are shown below.

[0175]

[Chemical formula 66]

[0176]

[Chemical formula 67]

[0177]

[Chemical 68]

Examples 1 to 27 and Comparative Examples 1 and 2 (Preparation and Evaluation of Positive Resist Composition) 2 g of each resin shown in Table 2 synthesized in the above Synthesis Example and a photoacid generator (in the table, Table 2 shows each compounding amount), an organic basic compound (amine) 4 mg, and a surfactant (10 mg) if necessary.
And dissolved in a 70/30 mixed solvent of PGMEA / ethyl lactate in a proportion of 14% by weight of solid content, respectively, and then filtered through a 0.1 μm microfilter to give Examples 1-27 and Comparative Example 1. .About.2 positive resist compositions were prepared.

The resins used in Comparative Examples 1 and 2 are those disclosed in JP-A-2
The resin (20) described in 001-109154 was used. In addition, the mixing ratio of the mixture is shown in parentheses in the column of the basic compound in the table.

[0180]

[Table 3]

As the surfactant, W1: Megafac F176 (manufactured by Dainippon Ink and Chemicals, Inc.)
(Fluorine type) W2: Megafac R08 (manufactured by Dainippon Ink and Chemicals, Inc.)
(Fluorine and silicone type) W3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) W4: Polyoxyethylene nonylphenyl ether W5: Troisol S-366 (Troy Chemical Co., Ltd.)
Manufactured).

As the amine, 1 represents 1,5-diazabicyclo [4.3.0] -5-nonene (DBN),
2 is bis (1,2,2,6,6-pentamethyl-4-
Piperidyl) sebacate 3, trioctylamine 4, triphenylimidazole 5, antipyrine 6 represents 2,6-diisopropylaniline.

(Evaluation test) First, Brewer Sci
ence DUV30J is applied on a silicon wafer by a spin coater to a thickness of 160 nm and dried, and then the positive resist composition solution obtained is applied onto the silicon wafer.
Dry for 90 seconds at 30 ° C. to form a positive photoresist film of about 0.4 μm, and add an ArF excimer laser (wavelength 193 nm, NA = 0.6, manufactured by Ultratech Co., Ltd. A
It was exposed with an rF stepper). 12 heat treatments after exposure
Perform for 90 seconds at 0 ° C, develop with 2.38% tetramethylammonium hydroxide aqueous solution, rinse with distilled water,
A resist pattern profile was obtained. The resist pattern of the silicon wafer thus obtained was observed with a scanning microscope (SEM), and the resist was evaluated as follows.

[Pattern collapse] The pattern collapse is 0.
With respect to the exposure amount E1 for reproducing a mask pattern of 13 μm (L / S = 1/1), the pattern collapse when the focus is further changed by ± 0.4 μm on the overexposure side is observed by SEM, and the pattern collapse The exposure amount at which is generated is E2, and (E2-E1) x 100 / E1 (%) is used as an index of pattern collapse. The larger the value, the better the pattern collapse prevention property, while the smaller the value, the worse.

[Surface Roughness During Etching] A contact hole pattern of 0.15 μm was etched with CHF ₃ / O ₂ = 8/2 plasma or CHF ₃ / O ₂ = 13/6 plasma for 60 seconds to obtain a sample obtained. Cross-section and surface are observed by SEM and pinhole-like defects (the lower layer of the unprocessed part is etched) are shown as ×, surface roughness occurs but no defects occur, but hole deformation The samples with "A" were evaluated as "B", and the samples having a small surface roughness and no hole deformation were evaluated as "B". Table 3 shows these evaluation results.
Shown in.

[Line Edge Roughness] There is an edge in the range of 5 μm in the longitudinal direction of the 130 nm line pattern obtained by the minimum exposure amount for reproducing the 130 nm (line / space = 1/1) line pattern in the mask. The distance from the power line was measured by S-9220 manufactured by Hitachi, Ltd. at 50 points, the standard deviation was calculated, and 3σ was calculated. The smaller the value, the better the performance.

[Sparse / Dense Dependency] 150n at an exposure amount for reproducing a 130 nm mask pattern (pitch 1/1)
The line width variation rate of the m isolated line pattern was measured. The results of these evaluations are shown in Table 3.

[0188]

[Table 4]

As is clear from the results shown in Table 3, the positive resist composition of the present invention is excellent in terms of preventing pattern collapse, surface roughness during etching, line edge roughness and sparse / dense dependence.

[0190]

The positive resist composition of the present invention is excellent in preventing pattern collapse, surface roughness during etching, line edge roughness and dependency on density.
Therefore, it is preferably used for lithography using deep ultraviolet rays such as ArF excimer laser exposure. Particularly, a remarkable effect is obtained when the acid-decomposable resin A contains a repeating unit A1 having a dihydroxy or trihydroxyadamantyl group, a repeating unit A2 having an acid-decomposable alicyclic group and an alicyclic lactone repeating unit A3. .

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H025 AA03 AA04 AB16 AC04 AC08                       AD03 BE00 BE10 BG00 CB14                       CB41 CB45 FA17                 4J100 AL08P AL08Q AL08R BA02Q                       BA03P BA12Q BA12R BC02Q                       BC04Q BC08Q BC09P BC09Q                       BC12Q BC53R CA05 JA38

Claims (6)

[Claims] 1. An alkali developing solution containing (A) at least a repeating unit A1 having a dihydroxyadamantyl group or a trihydroxyadamantyl group and a repeating unit A2 having an acid-decomposable alicyclic group as constituent units, and acting by an acid. A positive resist composition containing a resin having an increased dissolution rate with respect to a resin, and (B) a compound capable of generating an acid upon irradiation with actinic rays or radiation, wherein the repeating unit A1 and the repeating unit A2 are contained in the resin (A). The composition molar ratio A1 / A2 of 0.15 or more and 1.0 or less,
A positive resist composition, wherein the total content of the repeating unit A1 and the repeating unit A2 in the resin (A) is 40 to 70 mol%. 2. The composition according to claim 1, wherein A1 / A2 is 0.35 or more and 1.0 or less. 3. A repeating unit A1 having a dihydroxyadamantyl group or a trihydroxyadamantyl group.
Is a repeating unit represented by the following general formula (I), The composition according to claim 1 or 2. [Chemical 1] In the general formula (I), R ₁ is a hydrogen atom, an alkyl group,
It represents a halogen atom or a cyano group, and R ₂ represents a hydrogen atom or a hydroxyl group. 4. A repeating unit A having an acid-decomposable alicyclic group.
The composition according to any one of claims 1 to 3, wherein 2 is selected from the group of repeating units having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI). . [Chemical 2] (In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z represents an alicyclic hydrocarbon group together with a carbon atom. Represents an atomic group necessary to form R _12.
To R ₁₆ each independently represent a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R _{12 to} R ₁₄ or R _15; ,
One of R ₁₆ represents an alicyclic hydrocarbon group. R ₁₇ ~ R ₂₁
Each independently represents a hydrogen atom, a straight-chain or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group,
However, at least one of R _{17 to} R ₂₁ represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ has 1 to 1 carbon atoms.
Represents four linear or branched alkyl groups or alicyclic hydrocarbon groups. R _{22 to} R ₂₅ each independently have 1 to 1 carbon atoms.
It represents four linear or branched alkyl groups or alicyclic hydrocarbon groups, provided that at least one of R _{22 to} R ₂₅ represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may combine with each other to form a ring. ) 5. The composition according to claim 1, wherein the resin (A) further contains an alicyclic lactone repeating unit A3 as a constituent unit. 6. The composition according to claim 5, wherein the alicyclic lactone repeating unit A3 is a repeating unit having a group represented by any one of the following general formulas (V-1) to (V-4). [Chemical 3] In the general formulas (V-1) to (V-4), R _{1b to} R _1b
5b's each independently represent hydrogen or an alkyl group, cycloalkyl group or alkenyl group which may have a substituent.
Two of R _{1b to} R _5b may combine with each other to form a ring.