JP2003015301A - Positive type resist composition and method for forming resist film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive type resist composition suitable for use under a light source for exposure which emits light of <=160 nm, particularly F2 excimer laser light (157 nm) and a method for forming a resist film and to concretely provide a positive type resist composition which exhibits satisfactory transmittance when a light source of 157 nm is used and has good contrast by dissolution and good critical resolving power and a method for forming a resist film. SOLUTION: The positive type resist composition contains (A) a resin which has at least one repeating unit with a specified structure and is decomposed by the action of an acid to increase its solubility in an alkali developing solution, (B) a compound which generates the acid when irradiated with active light or radiation and (C) a solvent. The method for forming a resist film uses the positive type resist composition.

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 and a method for forming a resist film, which are suitable for use in microlithography processes such as manufacturing of ultra-LSIs and high-capacity microchips, and other photofabrication processes. It is about. More specifically, 1
The present invention relates to a positive resist composition and a method for forming a resist film, which can form a highly refined pattern using vacuum ultraviolet light of 60 nm or less.

[0002]

2. Description of the Related Art The degree of integration of integrated circuits is increasing more and more, and in the manufacture of semiconductor substrates such as VLSI, it has become necessary to process ultrafine patterns having a line width of less than quarter micron. It was As one of means for achieving a finer pattern, it is known to shorten the wavelength of an exposure light source used when forming a resist pattern.

For example, to manufacture a semiconductor device with an integration degree of up to 64 Mbits, up to now, the i-line (365n) of a high pressure mercury lamp has been used.
m) has been used as a light source. As a positive resist compatible with this light source, many compositions containing a novolac resin and a naphthoquinonediazide compound as a photosensitive material have been developed, and have achieved sufficient results in processing line widths up to about 0.3 μm. . Further, KrF excimer laser light (248 nm) has been adopted as an exposure light source instead of the i-line in the manufacture of a semiconductor device having an integration degree of 256 Mbits or more. Furthermore, for the purpose of manufacturing semiconductors with a degree of integration of 1 Gbit or more, the use of ArF excimer laser light (193 nm), which is a light source with a shorter wavelength in recent years, has a
The use of F ₂ excimer laser light (157 nm) has been studied to form a pattern of m or less.

With the shortening of the wavelength of these light sources, the constituent components of the resist material and the compound structure thereof have changed greatly. That is, in the conventional resist containing a novolac resin and a naphthoquinonediazide compound, since absorption in the far ultraviolet region of 248 nm is large, it is difficult for light to reach the bottom of the resist, and only a tapered pattern with low sensitivity can be obtained. To solve such problems, 24
Composition in which a compound (photo-acid generator) that generates an acid by irradiation with far-ultraviolet light is used by using as a main component a resin that has a basic skeleton of poly (hydroxystyrene) having a small absorption in the 8 nm region and is protected by an acid-decomposing group. The thing, what is called a chemically amplified resist, came to be developed. Since the chemically amplified resist changes its solubility in a developing solution due to the catalytic decomposition reaction of the acid generated in the exposed portion, a highly sensitive and high resolution pattern can be formed.

However, when ArF excimer laser light (193 nm) is used, since the compound having an aromatic group essentially has a large absorption in the wavelength region of 193 nm, sufficient performance cannot be obtained even with the above chemically amplified resist. It was

To solve this problem, an acid-decomposable resin having a basic skeleton of poly (hydroxystyrene) is used as an acid-decomposable resin in which an alicyclic structure having no absorption at 193 nm is introduced into the polymer main chain or side chain. Instead, the chemically amplified resist is being improved.

However, the absorption of F ₂ excimer laser light (157 nm) in the 157 nm region is large even in the alicyclic resin described above, and the target 0.1 μm
It was found to be insufficient to obtain the following pattern. On the other hand, a resin having a fluorine atom (perfluoro structure) introduced may have sufficient transparency at 157 nm.
Proc. SPIE. Vol.3678. 13 (1999), the structure of the effective fluororesin is Proc. SPIE. Vol.3999. 330 (2000), 357 (2000), 365 ( 2000), WO-
It has been proposed in No. 00/17712. However, the resist containing these fluororesins,
The dissolution contrast and the limit resolution of the exposed and unexposed areas were not always sufficient.

[0008]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to obtain a light of 160 nm or less, especially F ₂ excimer laser light (1
(57 nm) exposure light source, and a method for forming a positive resist composition and a resist film suitable for use with the exposure light source. Specifically, it exhibits sufficient transparency when using a 157 nm light source, and has a dissolution contrast and a limit. It is an object of the present invention to provide a positive resist composition having a good resolution and a method for forming a resist film.

[0009]

Means for Solving the Problems The inventors of the present invention, as a result of diligent study in consideration of the above-mentioned various characteristics, have found that the object of the present invention can be successfully achieved by using the following specific composition. Has reached the present invention. That is, the present invention has the following configuration.

(1) (A) a resin having at least one repeating unit represented by the following general formula (I), which decomposes by the action of an acid and increases the solubility in an alkali developing solution, (B) an actinic ray or radiation. Containing a compound that generates an acid upon irradiation with (C) and a solvent at 110 ° C during film formation
The positive resist composition as described above is used by heating to a temperature of 150 ° C. or lower.

[0011]

[Chemical 10]

In the general formula (I), R ₁ represents a hydrogen atom, a fluorine atom or an alkyl group which may have a substituent.
R ₂ and R ₃ may be the same or different and may have a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group or a substituent, an alkoxy group, an acyl group, an alkyl group, a cycloalkyl group, It represents an alkenyl group, an aralkyl group or an aryl group. R ₄ represents a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group, an acyl group, an alkoxycarbonyl group or a group of the following general formula (II).

[0013]

[Chemical 11]

In the general formula (II), R_FiveAnd R₆Is the same
May be different from each other and have a hydrogen atom or a substituent.
May represent an alkyl group or a cycloalkyl group.
You R ₇Is an alkyl group which may have a substituent,
Cycloalkyl group, aralkyl group or aryl group
Represent Also, R_Five~ R₇Two of them combine to form a ring
May be.

(2) The positive resist composition as described in (1), wherein the resin (A) further has at least one repeating unit represented by the following general formula (III).

[0016]

[Chemical 12]

In the general formula (III), R₈And R₉Is the same
Or they may be different, such as hydrogen atom, halogen atom,
Shows an alkyl group which may have an ano group or a substituent.
You R _TenHas a hydrogen atom, a halogen atom, and a substituent
Alkyl group which may be present or -A ₁Represents a -CN group. A
₁Is a single bond or a divalent alkane which may have a substituent.
A xylene group, an alkenylene group, a cycloalkylene group
Is an arylene group or -O-CO-R₁₁-, -CO-O
-R₁₂-, -CO-N (R₁₃) -R₁₄Represents-. R₁₁,
R₁₂And R₁₄Can be the same or different,
Compound or ether group, ester group, amide group, urethane group
Or a divalent alkylene which may have an ureido group
Group, alkenylene group, cycloalkylene group or aryle
Represents a group. R ₁₃Is a hydrogen atom, even if it has a substituent
Good alkyl group, cycloalkyl group, aralkyl group or
Represents an aryl group.

(3) The resin of (A) further has at least one repeating unit represented by the following general formulas (IV) to (XII), wherein (1) or (2) is satisfied. Positive resist composition.

[0019]

[Chemical 13]

In the general formulas (IV) to (XII), R₁₅as well as
R₁₆May be the same or different and may be hydrogen atom,
Elementary atom, optionally substituted alkyl group, cyclo
Represents an alkyl group or an aryl group. R₁₇~ R₁₉Is the same
Same or different and may have a substituent
Represents an alkyl group, a cycloalkyl group or an aryl group.
You Also, R₁₅And R₁₆, R₁₅And R₁₇, R₁₈And R₁₉Is
They may combine with each other to form a ring. R₂₀Is the hydrogen source
Child, optionally substituted alkyl group, cycloalkyl group
Alkyl group, acyl group, alkoxycarbonyl group or hetero group
Represents a ring group. R_{twenty one}, R_{twenty two}And R_{twenty three}Is the same or different
May have a hydrogen atom, a halogen atom, or a substituent
It may represent an alkyl group or an alkoxy group. R_{twenty four}
Has a hydrogen atom, a halogen atom, a cyano group or a substituent.
Represents an optionally substituted alkyl group. R _{twenty five}Has a substituent
Optionally, alkyl group, cycloalkyl group, ara
It represents a alkyl group or an aryl group. B₁And B₂Is the same
May be different, and may have a single bond or a substituent.
Divalent alkylene group, alkenylene group, cycloal
Xylene group, arylene group or -O-CO-R
₂₆-, -CO-OR₂₇-Or-CO-N (R₂₈)
-R₂₉Represents-. R₂₆, R₂₇And R₂₉Is the same but different
May be a single bond or an ether group, an ester group,
It may have an amide group, a urethane group or a ureido group.
Divalent alkylene group, alkenylene group, cycloal
It represents a xylene group or an arylene group. R₂₈Is a hydrogen atom,
Optionally substituted alkyl group, cycloalkyl
Represents a group, an aralkyl group or an aryl group. n is 0 or 1
Represents

(4) The resin according to any one of (1) to (3), wherein the resin (A) further has at least one repeating unit represented by the following general formula (XIII). Type resist composition.

[0022]

[Chemical 14]

In formula (XIII), R ₃₀ represents a hydrogen atom, an optionally substituted alkyl group, a cycloalkyl group or an aryl group.

(5) The resin (A) further comprises at least one of the repeating units represented by the following general formulas (XIV) and (XV) (1) to (4).
The positive resist composition as described in any one of 1.

[0025]

[Chemical 15]

In the general formulas (XIV) and (XV), R₃₁Over
And R₃₂May be the same or different and may be a hydrogen atom,
Rogen atom, cyano group or an optionally substituted group
Represents a rukyl group. R₃₃Is a hydrogen atom or -C (R₃₄)
(R₃₅) (R₃₆), -C (R₃₄) (R₃₅) (OR₃₇),
Alternatively, it represents a group represented by the following general formula (XVI). R
₃₄~ R₃₇May be the same or different and may be a hydrogen atom or
Is an optionally substituted alkyl group, cycloalkyl
Kill group, alkoxycarbonyl group, alkenyl group, ara
It represents a alkyl group or an aryl group. R₃₄, R₃₅, R₃₆
2 out of, or R₃₄, R₃₅, R₃₇Two of the
To form a ring. R in the general formula (XVI)₃₈Is
Optionally substituted alkyl group, cycloalkyl
Group, alkenyl group, alkynyl group, aralkyl group
Represents an aryl group. Z is a monocyclic ring together with a carbon atom or
Represents an atomic group constituting a polycyclic alicyclic group. A₂Is simple
, A divalent alkylene group which may have a substituent,
Cycloalkylene group, alkenylene group or aryle
Group or -O-CO-R₃₉-, -CO-OR₄₀-,
-CO-N (R₄₁) -R₄₂Represents-. R₃₉, R₄₀as well as
R₄₂Can be the same or different and can be a single bond or
Tellur group, ester group, amide group, urethane group or urethane group
A divalent alkylene group which may have a raid group, cyclo
Represents an alkylene group, alkenylene group or arylene group
You R₄₁Is a hydrogen atom, which may have a substituent,
It represents a rualkyl group, an aralkyl group or an aryl group. R₁,
R₂And R₃Is R in the general formula (I)₁, R₂And R₃
Is synonymous with.

[0027]

[Chemical 16]

(6) The positive resin as set forth in any one of (1) to (5), wherein the resin (A) further has at least one repeating unit represented by the following general formula (XVII). Type resist composition.

[0029]

[Chemical 17]

In the general formula (XVII), R ₄₃ , R ₄₄ and R
₄₅ may be the same or different and represents a hydrogen atom, a halogen atom, a cyano group or an alkyl group, an alkoxycarbonyl group or an alkoxy group which may have a substituent. _R46 is -C ( _R47 ) ( _R48 ) ( _R49 ), -C.
(R ₄₇ ) (R ₄₈ ) (OR ₅₀ ), or the following general formula (X
Represents a group represented by VIII). R _{47 to} R _{50, which} may be the same or different, each represents a hydrogen atom or a substituent, which represents an alkyl group, a cycloalkyl group, an alkoxycarbonyl group, an alkenyl group, an aralkyl group or an aryl group. Two of R ₄₇ , R ₄₈ , and R ₄₉ , or R
Two of ₄₇ , R ₄₈ and R ₅₀ may combine to form a ring. In general formula (XVIII), R ₅₁ represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aralkyl group or an aryl group, which may have a substituent. Za represents an atomic group constituting a monocyclic or polycyclic alicyclic group together with a carbon atom. n represents 0 or 1.

[0031]

[Chemical 18]

In the present invention, as a preferred embodiment,
Furthermore, the following aspects can be mentioned. (7) 1-methoxy-2-propanol acetate and / or 1-methoxy-2-propanol is contained as a solvent of (C), The positive in any one of (1)-(6) characterized by the above-mentioned. Type resist composition. (8) A method for forming a resist film, which comprises applying the positive resist composition as described in any one of (1) to (7) onto a substrate and heating at 110 to 150 ° C.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The compounds used in the present invention are described in detail below. [1] Resin of the present invention (A) The resin of the present invention (A) has at least one repeating unit represented by the general formula (I), decomposes by the action of an acid, and increases the solubility in an alkali developing solution. It is a resin. The resin in the present invention (A) may preferably further have at least one repeating unit represented by the general formulas (III) to (XV) and (XVII).

In the general formula (I), R ₁ represents a hydrogen atom, a fluorine atom or an optionally substituted alkyl group.
R ₂ and R ₃ may be the same or different and may have a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group or a substituent, an alkoxy group, an acyl group, an alkyl group, a cycloalkyl group, It represents an alkenyl group, an aralkyl group or an aryl group. R ₄ represents a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group, an acyl group, an alkoxycarbonyl group or a group of the above general formula (II).

In the general formula (II), R_FiveAnd R₆Is the same
May be different from each other and have a hydrogen atom or a substituent.
May represent an alkyl group or a cycloalkyl group.
You R ₇Is an alkyl group which may have a substituent,
Cycloalkyl group, aralkyl group or aryl group
Represent Also, R_Five~ R₇Two of them combine to form a ring
May be.

In the general formula (III), R₈And R₉Is the same
Or they may be different, such as hydrogen atom, halogen atom,
Shows an alkyl group which may have an ano group or a substituent.
You R _TenHas a hydrogen atom, a halogen atom, and a substituent
Alkyl group which may be present or -A ₁Represents a -CN group. A
₁Is a single bond or a divalent alkane which may have a substituent.
A xylene group, an alkenylene group, a cycloalkylene group
Is an arylene group or -O-CO-R₁₁-, -CO-O
-R₁₂-, -CO-N (R₁₃) -R₁₄Represents-. R₁₁,
R₁₂And R₁₄Can be the same or different,
Compound or ether group, ester group, amide group, urethane group
Or a divalent alkylene which may have an ureido group
Group, alkenylene group, cycloalkylene group or aryle
Represents a group. R ₁₃Is a hydrogen atom, even if it has a substituent
Good alkyl group, cycloalkyl group, aralkyl group or
Represents an aryl group.

In the general formulas (IV) to (XII), R₁₅as well as
R₁₆May be the same or different and may be hydrogen atom,
Elementary atom, optionally substituted alkyl group, cyclo
Represents an alkyl group or an aryl group. R₁₇~ R₁₉Is the same
Same or different and may have a substituent
Represents an alkyl group, a cycloalkyl group or an aryl group.
You Also, R₁₅And R₁₆, R₁₅And R₁₇, R₁₈And R₁₉Is
They may combine with each other to form a ring. R₂₀Is the hydrogen source
Child, optionally substituted alkyl group, cycloalkyl group
Alkyl group, acyl group, alkoxycarbonyl group or hetero group
Represents a ring group. R_{twenty one}, R_{twenty two}And R_{twenty three}Is the same or different
May have a hydrogen atom, a halogen atom, or a substituent
It may represent an alkyl group or an alkoxy group. R_{twenty four}
Has a hydrogen atom, a halogen atom, a cyano group or a substituent.
Represents an optionally substituted alkyl group. R _{twenty five}Has a substituent
Optionally, alkyl group, cycloalkyl group, ara
It represents a alkyl group or an aryl group. B₁And B₂Is the same
May be different, and may have a single bond or a substituent.
Divalent alkylene group, alkenylene group, cycloal
Xylene group, arylene group or -O-CO-R
₂₆-, -CO-OR₂₇-Or-CO-N (R₂₈)
-R₂₉Represents-. R₂₆, R₂₇And R₂₉Is the same but different
May be a single bond or an ether group, an ester group,
It may have an amide group, a urethane group or a ureido group.
Divalent alkylene group, alkenylene group, cycloal
It represents a xylene group or an arylene group. R₂₈Is a hydrogen atom,
Optionally substituted alkyl group, cycloalkyl
Represents a group, an aralkyl group or an aryl group. n is 0 or 1
Represents

In formula (XIII), R ₃₀ represents a hydrogen atom, an optionally substituted alkyl group, a cycloalkyl group or an aryl group.

In the general formulas (XIV) and (XV), R₃₁Over
And R₃₂May be the same or different and may be a hydrogen atom,
Rogen atom, cyano group or an optionally substituted group
Represents a rukyl group. R₃₃Is a hydrogen atom or -C (R₃₄)
(R₃₅) (R₃₆), -C (R₃₄) (R₃₅) (OR₃₇),
Alternatively, it represents a group represented by the above general formula (XVI). R
₃₄~ R₃₇May be the same or different and may be a hydrogen atom or
Is an optionally substituted alkyl group, cycloalkyl
Kill group, alkoxycarbonyl group, alkenyl group, ara
It represents a alkyl group or an aryl group. R₃₄, R₃₅, R₃₆
2 out of, or R₃₄, R₃₅, R₃₇Two of the
To form a ring. R in the general formula (XVI)₃₈Is
Optionally substituted alkyl group, cycloalkyl
Group, alkenyl group, alkynyl group, aralkyl group
Represents an aryl group. Z is a monocyclic ring together with a carbon atom or
Represents an atomic group constituting a polycyclic alicyclic group. A₂Is simple
, A divalent alkylene group which may have a substituent,
Cycloalkylene group, alkenylene group or aryle
Group or -O-CO-R₃₉-, -CO-OR₄₀-,
-CO-N (R₄₁) -R₄₂Represents-. R₃₉, R₄₀as well as
R₄₂Can be the same or different and can be a single bond or
Tellur group, ester group, amide group, urethane group or urethane group
A divalent alkylene group which may have a raid group, cyclo
Represents an alkylene group, alkenylene group or arylene group
You R₄₁Is a hydrogen atom, which may have a substituent,
It represents a rualkyl group, an aralkyl group or an aryl group. R₁,
R₂And R₃Is R in the general formula (I)₁, R₂And R₃
Is synonymous with.

In the general formula (XVII), R ₄₃ , R ₄₄ and R
₄₅ may be the same or different and represents a hydrogen atom, a halogen atom, a cyano group or an alkyl group, an alkoxycarbonyl group or an alkoxy group which may have a substituent. _R46 is -C ( _R47 ) ( _R48 ) ( _R49 ), -C.
(R ₄₇ ) (R ₄₈ ) (OR ₅₀ ), or the general formula (X
Represents a group represented by VIII). R _{47 to} R _{50, which} may be the same or different, each represents a hydrogen atom or a substituent, which represents an alkyl group, a cycloalkyl group, an alkoxycarbonyl group, an alkenyl group, an aralkyl group or an aryl group. Two of R ₄₇ , R ₄₈ , and R ₄₉ , or R
Two of ₄₇ , R ₄₈ and R ₅₀ may combine to form a ring. In general formula (XVIII), R ₅₁ represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aralkyl group or an aryl group, which may have a substituent. Za represents an atomic group constituting a monocyclic or polycyclic alicyclic group together with a carbon atom. n represents 0 or 1.

Examples of the above-mentioned alkyl group include linear and branched alkyl groups. The linear and branched alkyl groups are, for example, alkyl groups having 1 to 8 carbon atoms, specifically, methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, hexyl group. Base, 2
-Ethylhexyl group and octyl group are preferred. The cycloalkyl group may be monocyclic or polycyclic. The monocyclic type has 3 to 8 carbon atoms, and preferred examples thereof include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. The polycyclic type has 6 to 20 carbon atoms, and includes, for example, an adamantyl group, a norbornyl group, an isobornyl group, a camphanyl group, a dicyclopentyl group, an a-pinel group, a tricyclodecanyl group, a tetracyclododecyl group, An androstanyl group and the like can be preferably mentioned.

The aryl group has, for example, 6 to 1 carbon atoms.
5 aryl groups, specifically, a phenyl group,
Tolyl group, dimethylphenyl group, 2,4,6-trimethylphenyl group, naphthyl group, anthryl group, 9,10-
Preferred examples thereof include a dimethoxyanthryl group. The aralkyl group is, for example, an aralkyl group having a carbon number of 7 to 12, and specific examples thereof include a benzyl group, a phenethyl group and a naphthylmethyl group.

The alkenyl group has, for example, 2 to 2 carbon atoms.
8 alkenyl groups, specifically vinyl groups,
An allyl group, a butenyl group, and a cyclohexenyl group can be preferably mentioned. The alkoxy group is, for example, an alkoxy group having 1 to 8 carbon atoms, and specifically, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, a butoxy group, a pentoxy group, an allyloxy group, an octoxy group. A group and the like can be preferably mentioned.

The acyl group has, for example, 1 to 10 carbon atoms.
Specific examples of the acyl groups include formyl group, acetyl group, propanoyl group, butanoyl group, pivaloyl group, octanoyl group and benzoyl group. The alkoxycarbonyl group may be t-
Butoxycarbonyl group, t-amyloxycarbonyl group,
Examples thereof include tertiary alkoxycarbonyl groups such as 1-methyl-1-cyclohexyloxycarbonyl group. Examples of the alkynyl group include ethynyl group, propynyl group, butynyl group and the like. As a heterocyclic group,
Examples thereof include a tetrahydrofuryl group and a tetrahydropyryl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.

Examples of the alkylene group include linear and branched alkylene groups which may have a substituent. Examples of the linear and branched alkylene groups include those having 1 to 8 carbon atoms such as methylene group, ethylene group, propylene group, butylene group, hexylene group and octylene group. Examples of the cycloalkylene group include those having 5 to 8 carbon atoms such as a cyclopentylene group and a cyclohexylene group. As the alkenylene group, those having 2 to 6 carbon atoms such as an ethenylene group, a propenylene group and a butenylene group, which may have a substituent, can be mentioned. The arylene group is preferably an arylene group having a carbon number of 6 to 15, such as a phenylene group, a tolylene group and a naphthylene group which may have a substituent.

Two of R _{5 to} R ₇ , R ₁₅ and R ₁₆ , R ₁₅ and R ₁₇ , R ₁₈ and R ₁₉ , and two of R _{34 to} R ₃₆ , R ₃₄ ,
Two of R ₃₅ and R ₃₇ , two of R _{47 to} R ₄₉ or R
_The ring formed by combining two members of ₄₇ , R ₄₈ and R ₅₀ with each other is, for example, a 3- to 8-membered ring, and specifically includes a cyclopropane ring, a cyclopentane ring, a cyclohexane ring, a tetramethylene oxide ring. , Pentamethylene oxide ring,
Hexamethylene oxide ring, furan ring, pyran ring, dioxonol ring, 1,3-dioxolane ring and the like can be mentioned. Z and Za each represent an atomic group constituting a monocyclic or polycyclic alicyclic group, and the alicyclic group formed is a monocyclic type having 3 to 8 carbon atoms, for example, A cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group can be preferably mentioned. The polycyclic type has 6 to 20 carbon atoms and includes, for example, an adamantyl group, a norbornyl group, an isobornyl group, a camphanyl group, a dicyclopentyl group, an a-pinel group, a tricyclodecanyl group, a tetracyclododecyl group, An androstanyl group and the like can be preferably mentioned.

The alkyl group, cycloalkyl group, alkoxy group, acyl group, alkenyl group, aralkyl group, aryl group, alkoxycarbonyl group and the like may have a substituent. Substituents substituted on these groups include those having active hydrogen such as amino group, amide group, ureido group, urethane group, hydroxyl group and carboxyl group,
Halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), thioether group, acyl group (acetyl group, propanoyl group, benzoyl group, etc.), Acyloxy group (acetoxy group, propanoyloxy group, benzoyloxy group, etc.), alkoxycarbonyl group (methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, etc.), alkyl group (butyl group, cyclohexyl group), cyano group, nitro group Etc.

Action of acid contained in the resin of the present invention (A)
Examples of the group that is decomposed by and shows alkali solubility include
-OC (R₃₄) (R₃₅) (R₃₆), -OC (R₃₄)
(R ₃₅) (OR₃₇), -O-COO-C (R₃₄)
(R₃₅) (R₃₆), -OC (R₀₁) (R₀₂) COO-
C (R₃₄) (R₃₅) (R₃₆), -COO-C (R₃₄)
(R₃₅) (R₃₆), -COO-C (R₃₄) (R₃₅) (O
R₃₇) And the like. R₃₄~ R₃₇Is synonymous with the above (however
, Except hydrogen atom), and R₀₁, R₀₂Is the hydrogen source
Child, alkyl optionally having substituents shown above
Group, alkenyl group, aralkyl group, or aryl group
Represents

A preferred specific example is a t-butyl group,
t-amyl group, 1-alkyl-1-cyclohexyl group,
2-alkyl-2-adamantyl group, 2-adamantyl-2-propyl group, 2- (4-methylcyclohexyl)
Ether group or ester group of tertiary alkyl group such as 2-propyl group, acetal group or acetal ester group such as 1-alkoxy-1-ethoxy group, tetrahydropyranyl group, t-alkyl carbonate group, t-alkylcarbonyl A methoxy group and the like are preferable. More preferably, it is an acetal group such as a 1-alkoxy-1-ethoxy group or a tetrahydropyranyl group. In the case of an acetal group, the acid decomposability is large, the range of selection of the acid generating compound to be used in combination is widened, and it is effective in terms of the improvement of sensitivity, performance fluctuation with the elapse of time after exposure and heating. Particularly preferred is an acetal group containing an alkoxy group derived from the above perfluoroalkyl group as the 1-alkoxy component of the acetal group. In this case, the transmittance of short-wave exposure light (for example, 157 nm of F ₂ excimer laser light) can be further improved.

The content of the repeating unit represented by the general formula (I) is generally 0.1 to 1 in the total polymer composition.
It is used in an amount of 00 mol%, preferably 0.5 to 80 mol%, and more preferably 1 to 70 mol%. General formula (I
The content of the repeating unit represented by II) is generally 0.1 to 50 mol%, preferably 1 to 40 mol%, more preferably 1.5 to 35 mol% in the total polymer composition.
Used in the range of. The content of the repeating units represented by formulas (IV) to (IX) is generally 0.1 to 50 mol%, preferably 1 to 40 in the total polymer composition.
It is used in the range of mol%, more preferably 1.5 to 35 mol%. The content of the repeating unit represented by the general formula (X) is generally 0.1 to 30 in the total polymer composition.
It is used in the range of mol%, preferably 1 to 20 mol%, more preferably 1.5 to 15 mol%. General formula (X
The content of the repeating unit represented by I) is generally 0.1 to 30 mol%, preferably 1 to 20 mol%, more preferably 1.5 to 15 mol% in the total polymer composition. used. The content of the repeating unit represented by the general formula (XII) is generally 0.1 to 30 mol%, preferably 1 to 20 mol%, more preferably 1.5 to 15 mol% in the total polymer composition. Used in the range of. The content of the repeating unit represented by the general formula (XIII) is generally 0.1 to 30 mol%, preferably 1 to 20 mol%, more preferably 1.5 in the total polymer composition.
Used in the range of ~ 15 mol%. The content of the repeating unit represented by the general formula (XIV) is generally 0.1 to 60 mol%, preferably 1 to 5 in the total polymer composition.
It is used in an amount of 0 mol%, more preferably 1.5 to 40 mol%. The content of the repeating unit represented by the general formula (XV) is generally 0.1 to 0.1 in the total polymer composition.
It is used in the range of 60 mol%, preferably 1 to 50 mol%, more preferably 1.5 to 40 mol%. General formula (X
The content of the repeating unit represented by VII) is generally in the range of 0.1 to 40 mol%, preferably 1 to 30 mol%, and more preferably 1.5 to 20 mol% in the total polymer composition. used.

The resin of the present invention (A) may be copolymerized with other polymerizable monomers in addition to the above repeating structural units for the purpose of further improving the performance of the positive resist of the present invention. .

Copolymerizable monomers that can be used include those shown below. For example, addition-polymerizable unsaturated bonds selected from acrylic acid esters, acrylamides, methacrylic acid esters, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, crotonic acid esters, etc. other than the above It is a compound having one.

Specifically, for example, acrylic acid esters such as alkyl (wherein the alkyl group has 1 to 1 carbon atoms).
0 is preferred) Acrylate (eg, methyl acrylate, ethyl acrylate, propyl acrylate, amyl acrylate, cyclohexyl acrylate, ethylhexyl acrylate, octyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate 2,
2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.) Aryl acrylate (eg phenyl acrylate etc.);

Methacrylic acid esters, for example, alkyl (alkyl groups preferably having 1 to 10 carbon atoms) methacrylate (for example, methyl methacrylate,
Ethylmethacrylate, propylmethacrylate, isopropylmethacrylate, amylmethacrylate, hexylmethacrylate, cyclohexylmethacrylate,
Benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate,
5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, etc., aryl methacrylate (for example, phenyl methacrylate) , Cresyl methacrylate, naphthyl methacrylate, etc.);

Acrylamides such as acrylamide, N-alkylacrylamide, and the like (alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, butyl, t-butyl, and heptyl. Group, octyl group, cyclohexyl group, benzyl group, hydroxyethyl group, benzyl group, etc.), N-arylacrylamide (as the aryl group, for example, phenyl group, tolyl group, nitrophenyl group, naphthyl group,
There are cyanophenyl group, hydroxyphenyl group, carboxyphenyl group and the like. ), N, N-dialkylacrylamide (the alkyl group has 1 to 10 carbon atoms, for example, methyl group, ethyl group, butyl group, isobutyl group, ethylhexyl group, cyclohexyl group, etc.), N, N-diarylacrylamide (an aryl group includes, for example, a phenyl group), N-methyl-N-phenylacrylamide, N-hydroxyethyl-N-methylacrylamide, N-2-acetamidoethyl-N-acetylacrylamide, etc. ;

Methacrylamides, such as methacrylamide, N-alkylmethacrylamides (wherein the alkyl group is one having 1 to 10 carbon atoms, such as methyl group, ethyl group, t-butyl group, ethylhexyl group, hydroxyethyl group). Group, cyclohexyl group, etc.), N
-Aryl methacrylamide (an aryl group includes a phenyl group, etc.), N, N-dialkyl methacrylamide (an alkyl group includes an ethyl group, a propyl group, a butyl group, etc.), N, N-diaryl. Methacrylamide (such as a phenyl group as an aryl group), N-hydroxyethyl-N-methylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-ethyl-N-phenylmethacrylamide, etc .;
Allyl compounds, such as allyl esters (eg, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate), allyloxyethanol Such;

Vinyl ethers such as 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 aryl ether (eg vinyl phenyl ether, vinyl tolyl ether, vinyl chlorophenyl ether, vinyl-
2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl anthranyl ether, etc.);

Vinyl esters such as vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl barrate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate. , Vinyl phenylacetate, vinyl acetoacetate, vinyl lactate, vinyl-β-
Phenyl butyrate, vinyl cyclohexyl carboxylate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate, etc .;

Styrenes such as styrene, alkylstyrenes (eg methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, decylstyrene, benzylstyrene, chloromethyl). Styrene, trifluoromethylstyrene, ethoxymethylstyrene, acetoxymethylstyrene, etc.), alkoxystyrene (eg, methoxystyrene, 4-methoxy-3-methylstyrene, dimethoxystyrene, etc.), halogen styrene (eg, chlorostyrene, dichlorostyrene). , Trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromstyrene, dibromostyrene, iodostyrene, fluoros Ren, trifluoromethyl styrene, 2
-Bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene, etc.), carboxystyrene, vinylnaphthalene;

Crotonic acid esters, for example, alkyl crotonic acid (eg, butyl crotonic acid, hexyl crotonic acid, glycerin monocrotonate, etc.); Dialkyl itaconic acid (eg, dimethyl itaconic acid, diethyl itaconic acid, dibutyl itaconic acid, etc.) ); Dialkyl esters of maleic acid or fumaric acid (eg,
Dimethyl maleate, dibutyl fumarate, etc.) and the like. In addition, any addition-polymerizable unsaturated compound that is generally copolymerizable may be used.

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

[0062]

[Chemical 19]

[0063]

[Chemical 20]

[0064]

[Chemical 21]

[0065]

[Chemical formula 22]

[0066]

[Chemical formula 23]

Specific examples of the repeating structural units represented by formulas (III) to (XV) and (XVII) are shown below, but the invention is not limited thereto.

[0068]

[Chemical formula 24]

[0069]

[Chemical 25]

[0070]

[Chemical formula 26]

[0071]

[Chemical 27]

[0072]

[Chemical 28]

[0073]

[Chemical 29]

[0074]

[Chemical 30]

[0075]

[Chemical 31]

[0076]

[Chemical 32]

[0077]

[Chemical 33]

[0078]

[Chemical 34]

[0079]

[Chemical 35]

[0080]

[Chemical 36]

[0081]

[Chemical 37]

[0082]

[Chemical 38]

[0083]

[Chemical Formula 39]

[0084]

[Chemical 40]

The repeating structural units represented by the above specific examples may be used alone or in combination of two or more. The preferred molecular weight of the resin (A) of the present invention having the repeating structural unit is 1,000 to 2 on a weight average basis.
0,000, and more preferably 3,000 to 2
Used in the range of 10,000. Molecular weight distribution is 1-10
And preferably in the range of 1 to 3, more preferably 1 to 2. The smaller the molecular weight distribution,
The resolution, the resist shape, and the side wall of the resist pattern are smooth, and the roughness is excellent. The addition amount of the resin (A) of the present invention is generally in the range of 50 to 99.5% by weight, preferably 60 to 98% by weight, more preferably 65 to 95% by weight, based on the total solid content of the composition. Used in.

[2] The compound of the present invention (B) which generates an acid upon irradiation with actinic rays or radiation. The compound used in the present invention which decomposes upon irradiation with actinic rays or radiation to generate an acid is light. Photoinitiators for cationic polymerization, photoinitiators for photoradical polymerization, photobleaching agents for dyes, photochromic agents, or known light used for micro resists (4
Ultraviolet rays of from 0 to 200 nm, deep ultraviolet rays, particularly preferably g rays, h rays, i rays, KrF excimer laser light),
A compound that generates an acid by ArF excimer laser light, an electron beam, an X-ray, a molecular beam or an ion beam, and a mixture thereof can be appropriately selected and used.

Other compounds which generate an acid upon irradiation with actinic rays or radiation used in the present invention include SI Schlesinger, Photogr. Sci. En.
g., 18,387 (1974), TS Bal et al, Polymer, 21, 4
23 (1980) and the like diazonium salt, U.S. Pat.No. 4,069,
055, 4,069,056, Re 27,992, JP-A-3-401
Ammonium salts described in No. 40, DC Necker et al,
Macromolecules, 17, 2468 (1984), CS Wen et al, T
eh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1
988), U.S. Pat.Nos. 4,069,055 and 4,069,056 and other phosphonium salts, JV Crivello et al, Macromorec
ules, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 2
8, p31 (1988), European Patent Nos. 104,143, 339,049, 410,201, JP-A 2-150848, JP-A-2-296514, etc., iodonium salts, JVCrivello et al, Polym
er J. 17, 73 (1985), JV Crivello et al., J. Org.
Chem., 43, 3055 (1978), WR Watt et al, J. Polyme.
r Sci., Polymer Chem. Ed., 22, 1789 (1984), JV Cr
ivello et al, Polymer Bull., 14, 279 (1985), JV
Crivello et al, Macromorecules, 14 (5), 1141 (198)
1), JV Crivello et al, J. Polymer Sci., Polymer
Chem. Ed., 17, 2877 (1979), European Patent No. 370,693,
161,811, 410,201, 339,049, 233,567
No. 297,443, 297,442, U.S. Pat.No. 4,933,377
Issue 3,902,114, Issue 4,760,013, Issue 4,734,444,
No. 2,833,827, Dokoku Patent No. 2,904,626, No. 3,604,580
Nos. 3,604,581, etc., sulfonium salts, JVC
rivello et al, Macromorecules, 10 (6), 1307 (1977),
JV Crivello et al, J. Polymer Sci., Polymer Che
m. Ed., 17, 1047 (1979) etc., selenonium salt, C.
S. Wen et al, Teh, Proc.Conf. Rad. Curing ASIA, p
478 Tokyo, Oct (1988) and other onium salts such as arsonium salts, U.S. Pat.No. 3,905,815, Japanese Patent Publication No. 46-4605,
JP-A-48-36281, JP-A-55-32070, JP-A-60-23973
6, JP 61-169835, JP 61-169837, JP 6
2-58241, JP-A-62-212401, JP-A-63-70243, JP-A-63-298339 and the like, organic halogen compounds, K. Me
ier et al, J. Rad. Curing, 13 (4), 26 (1986), TPG
ill et al, Inorg. Chem., 19, 3007 (1980), D. Astru
c, Acc. Chem. Res., 19 (12), 377 (1896), JP-A-2-161
No. 445, etc., Organometallic / Organohalide, S. Haya
se et al, J. Polymer Sci., 25, 753 (1987), E. Reich
manis et al, J. Pholymer Sci., Polymer Chem. Ed.,
23, 1 (1985), QQ Zhuetal, J. Photochem., 36, 85,
39, 317 (1987), B. Amit et al, Tetrahedron Lett., (2
4) 2205 (1973), DHR Barton et al, J. Chem Soc.,
3571 (1965), PM Collins et al, J. Chem. Soc., P
erkin I, 1695 (1975), M. Rudinstein et al, Tetrahed.
ron Lett., (17), 1445 (1975), JW Walker et al,
J. Am. Chem. Soc., 110, 7170 (1988), SC Busman e
t al, J. Imaging Technol., 11 (4), 191 (1985), HM
Houlihan et al, Macromolecules, 21, 2001 (1988),
PMCollins et al, J. Chem. Soc., Chem. Commun., 5
32 (1972), S. Hayase et al, Macromolecules, 18, 179.
9 (1985), E. Reichmanis et al, J. Electrochem. Soc.,
Solid State Sci. Technol., 130 (6), FM Houlihan
et al, Macromolcules, 21, 2001 (1988), European Patent No. 02
90,750, 046,083, 156,535, 271,851,
0,388,343, U.S. Pat.No. 3,901,710, 4,181,531
M.TU, a photoacid generator having a 0-nitrobenzyl type protective group described in JP-A No. 60-198538, JP-A No. 53-133022 and the like.
NOOKA et al, Polymer Preprints Japan, 35 (8), G. Be
rner et al, J. Rad. Curing, 13 (4), WJ Mijs et
al, Coating Technol., 55 (697), 45 (1983), Akzo, H.A.
dachi et al, Polymer Preprints, Japan, 37 (3), European Patents 0199,672, 84515, 044,115, 618,56.
4, No. 0101,122, U.S. Patent Nos. 4,371,605, 4,431,
774, JP-A-64-18143, JP-A-2-245756, JP-A
Compounds which generate sulfonic acid by photolysis, represented by iminosulfonates described in JP-A 3-140109, and the like.
-166544 etc. can be mentioned.

A group in which an acid-generating group or a compound is introduced into the main chain or side chain of a polymer, for example, ME Woodho
useet al, J. Am. Chem. Soc., 104, 5586 (1982), S.
P. Pappas et al, J. Imaging Sci., 30 (5), 218 (198
6), S. Kondo et al, Makromol. Chem., Rapid Commu
n., 9, 625 (1988), Y. Yamada et al, Makromol. Che
m., 152, 153, 163 (1972), JV Crivello et al, J.
Polymer Sci., Polymer Chem. Ed., 17, 3845 (1979),
U.S. Pat.No. 3,849,137, United States Patent No. 3914407, JP-A-63
-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-15385
The compounds described in JP-A No. 3 and JP-A No. 63-146029 can be used.

Further, VNR Pillai, Synthesis, (1),
1 (1980), A. Abad et al, Tetrahedron Lett., (47) 45.
55 (1971), DHR Barton et al, J. Chem. Soc.,
(C), 329 (1970), U.S. Patent No. 3,779,778, European Patent No. 1
The compounds which generate an acid by the light described in No. 26,712 and the like can also be used.

Among the compounds which decompose to generate an acid upon irradiation with actinic rays or radiation, those which are particularly effectively used are described below. (1) The following general formula (PAG) substituted with a trihalomethyl group
1) an oxazole derivative or a general formula (PAG
An S-triazine derivative represented by 2).

[0091]

[Chemical 41]

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
Indicates. Y represents a chlorine atom or a bromine atom. The following compounds can be specifically mentioned, but the compounds are not limited to these.

[0093]

[Chemical 42]

[0094]

[Chemical 43]

[0095]

[Chemical 44]

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

[0097]

[Chemical formula 45]

Here, the formulas Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. Preferable substituents include an alkyl group, a haloalkyl group, a cycloalkyl group, an aryl group, an alkoxy group, a nitro group, a carboxyl group, an alkoxycarbonyl group, a hydroxy group, a mercapto group and a halogen atom.

R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ each independently represent a substituted or unsubstituted alkyl group or aryl group. Preferably, an aryl group having 6 to 14 carbon atoms and 1 to 8 carbon atoms
Are alkyl groups and substituted derivatives thereof. Preferred substituents are an alkoxy group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, a nitro group, a carboxyl group, a mercapto group, a hydroxy group and a halogen atom for an aryl group. For an alkyl group, an alkoxy group having 1 to 8 carbon atoms, a carboxyl group, and an alkoxycarbonyl group.

Z ⁻ represents an anion, specifically, an alkyl sulfonic acid which may have a substituent, a cycloalkyl sulfonic acid, a perfluoroalkyl sulfonic acid, an aryl sulfonic acid (for example, a substituent having a substituent). Examples of each anion include benzene sulfonic acid, naphthalene sulfonic acid, anthracene sulfonic acid).

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.

[0103]

[Chemical formula 46]

[0104]

[Chemical 47]

[0105]

[Chemical 48]

[0106]

[Chemical 49]

[0107]

[Chemical 50]

[0108]

[Chemical 51]

[0109]

[Chemical 52]

[0110]

[Chemical 53]

[0111]

[Chemical 54]

[0112]

[Chemical 55]

The onium salts represented by the general formulas (PAG3) and (PAG4) are known, and for example, JW Knapcz.
yk et al, J. Am. Chem. Soc., 91, 145 (1969), AL
Maycok et al, J. Org. Chem., 35, 2532, (1970), E.
Goethas et al, Bull. Soc. Chem. Belg., 73, 546, (196
4), HM Leicester, J. Ame. Chem. Soc., 51, 3587.
(1929), JV Crivello et al, J. Polym. Chem. Ed.,
18, 2677 (1980), U.S. Pat.Nos. 2,807,648 and 4,247,
It can be synthesized by the method described in JP-A No. 473, JP-A-53-101331, etc.

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

[0115]

[Chemical 56]

In the formula, Ar³, Ar^FourReplace each independently
Or an unsubstituted aryl group. R ²⁰⁶Is replaced or
An unsubstituted alkyl group and an aryl group are shown. If A is replaced
Or unsubstituted alkylene group, alkenylene group, aryle
Group. Specific examples include the compounds shown below.
However, the present invention is not limited to these.

[0117]

[Chemical 57]

[0118]

[Chemical 58]

[0119]

[Chemical 59]

[0120]

[Chemical 60]

[0121]

[Chemical formula 61]

[0122]

[Chemical formula 62]

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

[0124]

[Chemical formula 63]

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

[0126]

[Chemical 64]

(5) An oxime sulfonate derivative represented by the following general formula (PAG8).

[0128]

[Chemical 65]

In the formula, R ₂₀₇ represents a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group or aralkyl group. R ₂₀₈ and R ₂₀₉ represent a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group, aralkyl group, cyano group or acyl group. R ₂₀₈ and R ₂₀₉ may combine to form a carbon ring or a heterocycle having an oxygen atom, a nitrogen atom or a sulfur atom. Specific examples include the compounds shown below, but the invention is not limited thereto.

[0130]

[Chemical formula 66]

The amount of the compound which generates an acid upon irradiation with actinic rays or radiation of the present invention (B) is generally 0.1 to 20% by weight based on the total solid content of the composition of the present invention. And preferably 0.5 to 10% by weight, more preferably 1 to 7% by weight. These compounds may be used alone or in combination of two or more.

[3] Solvent of the present invention (C) The composition of the present invention is dissolved in a solvent that dissolves each of the above components and coated on a support. As the solvent used here,
1-methoxy-2-propanol acetate, 1-methoxy-2-propanol, 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 monoethyl 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 and the like are preferable, and 1 -Methoxy-
2-Propanol acetate and 1-methoxy-2-propanol are more preferable. These solvents are used alone or as a mixture.

[4] Acid Diffusion Inhibitor that can be Used in the Present Invention The composition of the present invention has a performance variation (T-to-pattern of the pattern) with the passage of time from irradiation with actinic rays or radiation to heat treatment.
(P shape formation, sensitivity fluctuation, pattern line width fluctuation, etc.) and performance fluctuation with time after coating, and further, after irradiation with actinic rays or radiation, excessive diffusion of acid (deterioration of resolution) during heat treatment. Therefore, it is preferable to add an acid diffusion inhibitor. The acid diffusion inhibitor is an organic basic compound,
For example, an organic base compound containing basic nitrogen, and a compound having a pKa value of the conjugate acid of 4 or more is preferably used. Specifically, the structures of the following formulas (A) to (E) can be mentioned.

[0134]

[Chemical formula 67]

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² may be the same or different and each is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aminoalkyl group having 1 to 6 carbon atoms, or 1 carbon atom. ~ 6 hydroxyalkyl group or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, wherein R is
²⁵¹ and R ²⁵² may combine with each other to form a ring. R
²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ^{256, which} may be the same or different, each represents an alkyl group having 1 to 6 carbon atoms. More preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms having different chemical environments in one molecule, and particularly preferably both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom. It is a compound containing or a compound having an alkylamino group.

Preferred specific examples are substituted or unsubstituted guanidine, substituted or unsubstituted aminopyridine, substituted or unsubstituted aminoalkylpyridine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted indazole, imidazole, 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 Alternatively, unsubstituted aminomorpholine, substituted or unsubstituted aminoalkylmorpholine and the like can be mentioned. Preferred substituents are amino group, aminoalkyl group, alkylamino group, aminoaryl group, arylamino group, alkyl group, alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, nitro group, hydroxyl group, cyano group. Is.

Particularly preferable compounds are guanidine,
1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, imidazole, 2-methylimidazole, 4-methylimidazole, N-methylimidazole, 2-phenylimidazole, 4,5-diphenylimidazole, 2 , 4,5-Triphenylimidazole, 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-aminoethyl) 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 and the like, but not limited thereto. These nitrogen-containing basic compounds may be used alone or in combination of two or more.

The ratio of the acid generator and the organic basic compound used in the composition is preferably (acid generator) / (organic basic compound) (molar ratio) = 2.5 to 300. If the molar ratio is less than 2.5, the sensitivity may be low and the resolution may be lowered. If the molar ratio is more than 300, the resist pattern may become thicker with the lapse of time after the post-exposure heat treatment, and the resolution may be lowered. . The (acid generator) / (organic basic compound) (molar ratio) is preferably 5.0 to 200, more preferably 7.0 to 150.

[5] Fluorine-based and / or silicon-based surfactant that can be used in the present invention The positive resist composition of the present invention can contain a fluorine-based and / or silicon-based surfactant. . That is, the positive resist composition of the present invention contains at least one of a fluorine-based surfactant, a silicon-based surfactant, and a surfactant containing both a fluorine atom and a silicon atom, or two or more thereof. You can These fluorine-based and
The addition of a silicon-based surfactant is effective in suppressing development defects and improving coatability.

Examples of these surfactants include those disclosed in
62-36663, JP-A-61-226746, JP-A-61-226745,
JP 62-170950 A, JP 63-34540 A, JP 7-23016 A
5, JP 8-62834A, JP 9-54432A, JP 9-598A
8, U.S. Pat.No. 5,405,720, U.S. Pat.No. 5,360,692, U.S. Pat.No. 5,528,981, U.S. Pat.No. 5,296,330, U.S. Pat.
U.S. Patent No. 5576143, U.S. Patent No. 5296143, U.S. Patent
5294511 and US Pat. No. 5,824,451 can be mentioned, and the following commercially available surfactants can be used as they are. Examples of such commercially available surfactants include F-top EF301, EF303, EF352 (Shin-Akita Kasei)
Fluoro FC430, 431 (Sumitomo 3M Limited)
Made), MegaFac F171, F173, F176, F189, R08 (made by Dainippon Ink and Chemicals), Asahi Guard AG710, Surflon S
-382, SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (manufactured by Troy Chemical Co., Ltd.) and the like fluorine-based surfactants or silicon-based surfactants can be mentioned. . Also polysiloxane polymer KP
-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as the 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.

In the step of forming a pattern on a resist film in the production of precision integrated circuit devices, etc., first, the present invention is applied to a substrate (eg, silicon / silicon dioxide covering, glass substrate, transparent substrate such as ITO substrate). The positive type resist composition is applied and heated to form a resist film. The heating temperature may be 110 to 150 ° C., preferably 130
To 150 ° C, more preferably 140 to 150 ° C. If the heating temperature is lower than 110 ° C, the amount of residual solvent may increase, and a sufficient effect may not be obtained. On the other hand, if the heating temperature exceeds 150 ° C., the resin and the photo-acid generator may be thermally decomposed and a pattern may not be formed. The heating time may be 10 to 400 seconds, preferably 20 to 300 seconds, more preferably 30 to 200 seconds.
Seconds. Then, irradiation with an actinic ray or radiation drawing device is performed, and heating, development, rinsing, and drying are performed to form a good resist pattern.

The developer for the positive resist composition of the present invention includes sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, inorganic alkalis such as aqueous ammonia, ethylamine, n-propylamine. Primary amines such as diethylamine, di-
Secondary amines such as n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and primary amines such as choline. An aqueous solution of alkali such as quaternary ammonium salt, cyclic amines such as pyrrole and piperidine, and the like can be used. Furthermore, alcohols such as isopropyl alcohol and surfactants such as nonionic surfactants may be added to the aqueous solution of the above alkalis in appropriate amounts. Of these developers, quaternary ammonium salts are preferable, and tetramethylammonium hydroxide and choline are more preferable.

[0145]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the contents of the present invention are not limited thereto.

1. Synthesis Example [Synthesis Example 1] 13.5 g (0.05 mol) of 4- [bis (trifluoromethyl) -hydroxymethyl] styrene,
Methacrylonitrile (3.4 g, 0.05 mol) was dissolved in 1-methoxy-2-propanol (60 ml), and 2,2'-azobis (2,4-dimethylvaleronitrile) was used as a polymerization initiator (Wako Pure Chemical Industries ( Co., Ltd .; trade name V-65)
0.25g was added. This solution was added to 10 ml of 1-methoxy-2-propanol heated to 70 ° C. under a nitrogen stream,
The mixture was added dropwise with stirring for 2 hours. After the dropping, stirring was continued for another 4 hours. Then, the reaction solution was poured into 1 L of methanol / ion-exchanged water (1/1) with vigorous stirring. The precipitated resin was washed with deionized water, filtered, and dried under vacuum to obtain 14.8 g of a white resin. NMR
According to the measurement, this resin is structural example (I-1) / (III-
2) = 52/48 resin, and it was confirmed by GPC measurement that the weight average molecular weight (polystyrene standard) was 8,900. This resin was dissolved in 100 ml of THF, 2.9 g (0.04 mol) of ethyl vinyl ether was added, and a catalytic amount of p-toluenesulfonic acid was added, followed by stirring at room temperature for 8 hours. P- was added to the reaction solution
The reaction was stopped by adding twice the amount of the toluenesulfonic acid catalyst, and the mixture was put into 3 L of ion-exchanged water with vigorous stirring. The precipitated resin is separated by filtration and dried to obtain the resin (1) of the present invention.
15.3 g was obtained. According to GPC measurement, the molecular weight of the resin (1) was 9,100 in weight average (Mw). Also H
When the composition of the resin (1) was examined by -NMR, C-NMR, and IR measurement, the structural example (I-1) / (I
-4) / (III-2) = 10/42/48.
Similarly, the resins of the present invention shown in Table 1 were synthesized.

[0147]

[Table 1]

2. Example (Measurement of Transmittance) In Table 2, 1.36 g of the resin shown in Table 2 and 0.04 g of triphenylsulfonium naphthalate salt were added, and propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) were shown in Table 2. A resist solution was prepared by dissolving in 8.5 g of a mixed solvent mixed at the weight ratio (PGMEA / PGME) shown.
Each resist solution was filtered through a 0.1 μm Teflon (registered trademark) filter, and then applied on a calcium fluoride disk by a spin coater, and dried by heating at a heating temperature shown in Table 2 for 90 minutes to give a 0.2. A resist film of 1 μm was obtained. The absorption of the coating film was measured with an Acton CAMS-507 spectrometer and the transmittance at 157 nm was calculated. The results are shown in Table 2. Comparative Examples 1 and 2
Polymer A used in KrF resist as:
p-Hydroxystyrene / p- (1-ethoxyethoxystyrene) (70/30) was similarly prepared and the transmittance was measured. Further, as Comparative Examples 3 to 5, the resin of the present invention was used, and the heating temperature was changed to measure the transmittance.

[0149]

[Table 2]

From the results in Table 2, using the composition of the present invention,
The resist film heated to 110 to 150 ° C during film formation is 1
It can be seen that it has sufficient transparency at 57 nm.

3. Example (Measurement of Dissolution Contrast) Using the resins shown in Table 3, a resist solution was prepared in the same manner as in the above example. After filtering each resist solution with a Teflon filter of 0.1 μm, it was applied on a silicon wafer treated with hexamethyldisilazane by a spin coater, and at a heating temperature shown in Table 3, on a vacuum type hot plate for 90 seconds. By heating and drying with, a resist film having a film thickness of 0.1 μm was obtained. 157n for the obtained resist film
Laser exposure / dissolution behavior analyzer VUVES-45
00 (manufactured by Lithotec Japan) was used to measure the dissolution contrast of the exposed and unexposed areas at 157 nm.
However, in Comparative Examples 1 and 2, KrF polymer was used and KrF exposure was performed. In addition, as Comparative Examples 3 to 5, the resin of the present invention was used, and the heating temperature was changed to measure the dissolution contrast. The results are shown in Table 3.

[0152]

[Table 3]

From the results in Table 3, using the composition of the present invention,
It can be seen that the resist film heated to 110 to 150 ° C. at the time of film formation has a dissolution contrast, that is, an image forming property, which is equal to or higher than that of the resist practically used for the KrF excimer of the comparative example.

4. Example (Measurement of limit resolution) Using the resins shown in Table 4, a resist solution was prepared in the same manner as in the above example. After filtering each resist solution with a 0.1 μm Teflon filter, it was applied on a silicon wafer treated with hexamethyldisilazane by a spin coater, and at a heating temperature shown in Table 4, on a vacuum adsorption type hot plate for 90 seconds. Then, it was dried by heating to obtain a resist film of 0.15 μm. 157n for the obtained resist film
m F ₂ laser exposure machine (Ultratech XLS157: NA0.6
Exposure was performed using 0, σ = 0.70). After exposure, heat on a 120 ° C hot plate for 90 seconds and immediately add 0.26N
Tetramethylammonium hydroxide (TMA
H) Immersed in the aqueous solution for 60 seconds, rinsed with water for 30 seconds, and then dried. The pattern on the silicon wafer thus obtained was observed with an electron microscope to obtain the resist performance (critical resolution). Evaluation of the limit resolution is 150 nmL
When the mask pattern corresponding to / S (1: 1) is irradiated with laser, the actual formation size on the wafer is 150.
At the exposure dose of nm, the index was used to determine how finely sized the pattern was separated and resolved. The results are shown in Table 4.

[0155]

[Table 4]

From the results in Table 4, using the composition of the present invention,
It can be seen that the resist film heated to 110 to 150 ° C. during film formation has a good limit resolution.

[0157]

According to the present invention, it is possible to form a resist film having sufficient transmittance even at a short wavelength of 157 nm, and having a good dissolution contrast and a limiting resolution.

Continued front page    F term (reference) 2H025 AA00 AA02 AC04 AC08 AD03                       BE00 BG00 CC03 FA03 FA12                       FA17                 4J100 AB07P AC21R AC22R AC26R                       AC27R AD13R AE35R AE38R                       AE39R AH02R AK32R AL08Q                       AL08R AM02Q AM03Q AM07Q                       AM43S AM47S AR04R AR09R                       AR11R AR32R BA02P BA02R                       BA03P BA03R BA04P BA04R                       BA06P BA06R BA07Q BA15P                       BA20P BA20R BA22P BA22R                       BA40Q BA53R BB01Q BB07P                       BB07Q BB07R BB13P BB13R                       BB18P BB18R BB18S BC04P                       BC04R BC04S BC08R BC09S                       BC12R BC53P BC53R CA01                       CA03 CA04 CA05 CA06 JA38

Claims (6)

[Claims] 1. A method represented by the following general formula (I):
Decomposes by the action of acid that has at least one return unit
Resin that increases the solubility in an alkaline developer,
(B) Generates an acid upon irradiation with actinic rays or radiation
Contains a compound and (C) solvent, and is 110 ° C or higher during film formation.
Specially, it is used by heating to a temperature of 150 ° C or less.
A positive resist composition. [Chemical 1] In the general formula (I), R₁Is hydrogen atom, fluorine atom, substitution
Represents an alkyl group which may have a group. R₂And R
₃May be the same or different, and may be a hydrogen atom, hydro
Having a xyl group, halogen atom, cyano group or substituent
Alkoxy group, acyl group, alkyl group,
Chloroalkyl group, alkenyl group, aralkyl group or
Represents an aryl group. R_FourHas a hydrogen atom and a substituent
Alkyl group, cycloalkyl group, acyl
Group, an alkoxycarbonyl group or a compound represented by the following general formula (II)
Represents a group. [Chemical 2] In the general formula (II), R_FiveAnd R₆Are the same or different
May have a hydrogen atom or a substituent,
It represents a alkyl group or a cycloalkyl group. R ₇Is
Alkyl group, cycloalkyl, which may have a substituent
Represents a group, an aralkyl group or an aryl group. Also, R
_Five~ R₇Two of them may combine to form a ring. 2. The resin of (A) is further represented by the following general formula (II
Having at least one repeating unit represented by I)
The positive resist composition according to claim 1, wherein
Stuff. [Chemical 3] In the general formula (III), R₈And R₉Is the same or different
It may be a hydrogen atom, a halogen atom, a cyano group or a group.
It represents an alkyl group which may have a substituent. R _TenIs water
Elementary atoms, halogen atoms, and optionally substituted alkyl
Kill group or -A ₁Represents a -CN group. A₁Is a single bond, substitution
A divalent alkylene group which may have a group, alkene
Len group, cycloalkylene group or arylene group, or
Is -O-CO-R₁₁-, -CO-OR₁₂-, -CO-
N (R₁₃) -R₁₄Represents-. R₁₁, R₁₂And R₁₄Is
May be the same or different, single bond or ether group,
Ester group, amide group, urethane group or ureido group
May have a divalent alkylene group, alkenylene
Represents a group, a cycloalkylene group or an arylene group. R ₁₃
Is a hydrogen atom or an alkyl which may have a substituent.
Group, cycloalkyl group, aralkyl group or aryl group
Represent 3. The resin of (A) further has the general formula (I
V) to (XII) at least the repeating units
The one according to claim 1 or 2 having one.
Di-type resist composition. [Chemical 4] R in the general formulas (IV) to (XII)₁₅And R₁₆Is the same
Or may be different, hydrogen atom, fluorine atom, substitution
An alkyl group or a cycloalkyl group which may have a group
Alternatively, it represents an aryl group. R₁₇~ R₁₉Are the same or different
Optionally, optionally substituted, alkyl
Represents a group, a cycloalkyl group or an aryl group. Also, R
₁₅And R₁₆, R₁₅And R₁₇, R₁₈And R₁₉And is bound to each other
May form a ring. R₂₀Has a hydrogen atom or a substituent
Optionally, an alkyl group, a cycloalkyl group, an acyl group
Group, an alkoxycarbonyl group or a heterocyclic group. R
_{twenty one}, R_{twenty two}And R_{twenty three}Can be the same or different, water
An elementary atom, a halogen atom, or an optionally substituted
Represents a alkyl group or an alkoxy group. R_{twenty four}Is a hydrogen atom,
It may have a halogen atom, a cyano group or a substituent.
Represents an alkyl group. R _{twenty five}May have a substituent
An alkyl group, a cycloalkyl group, an aralkyl group or
Represents an aryl group. B₁And B₂Are the same or different
Optionally, a single bond or a divalent alkane which may have a substituent.
A xylene group, an alkenylene group, a cycloalkylene group
Is an arylene group or -O-CO-R₂₆-, -CO-O-
R₂₇-Or-CO-N (R₂₈) -R₂₉Represents-. R
₂₆, R₂₇And R₂₉Can be the same or different,
Bond or ether group, ester group, amide group, urethane
A divalent alkyle which may have a group or a ureido group
Group, alkenylene group, cycloalkylene group or aryl
Represents a len group. R₂₈May have a hydrogen atom or a substituent.
An alkyl group, a cycloalkyl group, an aralkyl group or
Represents an aryl group. n represents 0 or 1. 4. The resin of (A) is further represented by the following general formula (XI
The positive resist composition according to claim 1, which comprises at least one of the repeating units represented by II). [Chemical 5] In formula (XIII), R ₃₀ represents a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group or an aryl group which may have a substituent. 5. The resin of (A) is further represented by the following general formula (XI
V) and (XV) of the repeating units
Any one of claims 1 to 4 having one
The positive resist composition as described in 1. [Chemical 6] R in the general formulas (XIV) and (XV)₃₁And R₃₂Is the same
Same or different, a hydrogen atom, a halogen atom,
Represents a cyano group or an alkyl group which may have a substituent.
You R₃₃Is a hydrogen atom or -C (R₃₄) (R₃₅)
(R₃₆), -C (R₃₄) (R₃₅) (OR₃₇), Or
It represents a group represented by the following general formula (XVI). R ₃₄~ R₃₇
May be the same or different and each represents a hydrogen atom or a substituent.
Which may have an alkyl group, a cycloalkyl group,
Alkoxycarbonyl group, alkenyl group, aralkyl group
Alternatively, it represents an aryl group. R₃₄, R₃₅, R₃₆2 of
Or R₃₄, R₃₅, R₃₇Two of the two combine to form a ring
You can do it. R in the general formula (XVI)₃₈Is a substituent
It may have an alkyl group, a cycloalkyl group,
Lucenyl group, alkynyl group, aralkyl group or ari
Group. Z is a monocyclic or polycyclic oil together with a carbon atom.
Represents an atomic group constituting a cyclic group. A₂Is a single bond, substitution
A divalent alkylene group which may have a group, cycloalkyl
A alkylene group, an alkenylene group or an arylene group, or
Is -O-CO-R₃₉-, -CO-OR₄₀-, -CO-
N (R₄₁) -R₄₂Represents-. R₃₉, R₄₀And R₄₂Is
May be the same or different, single bond or ether group,
Ester group, amide group, urethane group or ureido group
Which may have a divalent alkylene group, cycloalkyl
Group, an alkenylene group or an arylene group. R
₄₁Is a hydrogen atom or an alkyl which may have a substituent.
Represents a group, an aralkyl group or an aryl group. R₁, R₂as well as
R₃Is R in the general formula (I)₁, R₂And R₃Synonymous with
is there. [Chemical 7] 6. The resin of (A) further has the following general formula (XV
The positive resist composition according to claim 1, which has at least one repeating unit represented by II). [Chemical 8] In formula (XVII), R ₄₃ , R ₄₄ and R ₄₅ may be the same or different, and may be a hydrogen atom, a halogen atom, a cyano group or a substituent, an alkyl group or an alkoxycarbonyl group. Alternatively, it represents an alkoxy group. R ₄₆
Is -C (R ₄₇ ) (R ₄₈ ) (R ₄₉ ), -C (R ₄₇ ) (R
₄₈ ) (OR ₅₀ ) or a group represented by general formula (XVIII) shown below. R _{47 to} R _{50, which} may be the same or different, each represents a hydrogen atom or a substituent, which represents an alkyl group, a cycloalkyl group, an alkoxycarbonyl group, an alkenyl group, an aralkyl group or an aryl group. Two of R ₄₇ , R ₄₈ , and R ₄₉ , or R ₄₇ , R ₄₈ , and
Two of R ₅₀ may combine to form a ring. In general formula (XVIII), R ₅₁ represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aralkyl group or an aryl group, which may have a substituent.
Za represents an atomic group constituting a monocyclic or polycyclic alicyclic group together with a carbon atom. n represents 0 or 1. [Chemical 9]