JPH11295895A - Positive photoresist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resist compsn. having high sensitivity, high resolution and an excellent pattern profile to be used for a short wavelength light source by combining a specified structure of a resin and a photobase producing agent. SOLUTION: The positive photoresist compsn. used contains a compd. (a) having groups expressed by the formula which are decomposed by an acid to increase the solubility in an alkali developer, a compd. (b) which is decomposed by irradiation of active rays or radiation to produce an acid, and a compd. (c) which is decomposed by irradiation of active rays or radiation to produce a base. In the formula, R1 is a hydrogen atom or methyl group, R2 is a methyl group or ethyl group, and R3 is 1-4C alkyl group. The compd. (a) includes two kinds of an alkali-soluble resin (polymer type dissolution inhibiting compd.) containing groups expressed by the formula which can be decomposed by an acid, and a nonpolymer dissolution inhibiting compd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a super microlithography process such as the manufacture of a super LSI and a high capacity micro chip, and other photofabrication processes. More specifically, excimer laser
The present invention relates to a positive photoresist composition capable of forming a high-definition pattern using a far ultraviolet region including light.

[0002]

2. Description of the Related Art In a photofabrication process such as lithographic printing, manufacture of semiconductors such as ICs, and manufacture of circuit boards such as thermal heads, spin coating is performed on a substrate such as a semiconductor wafer, glass, ceramic, or metal. Alternatively, apply a photoresist to a thickness of 0.5 to 2.5 μm by a roller coating method, heat it, dry it, bake a circuit pattern or the like with an active light such as ultraviolet rays through an exposure mask, and after exposing as necessary. After baking, development is performed to form a resist image. Further, pattern processing on the substrate can be performed by etching using this image as a mask.

One of the positive photoresist compositions is a chemically amplified resist composition described in US Pat. No. 4,491,628 and European Patent 249,139. The chemically amplified positive resist composition generates an acid in the exposed area by irradiation with radiation such as deep ultraviolet light, and the reaction using the acid as a catalyst dissolves the active radiation irradiated area and the non-irradiated area in the developing solution. This is a composition that changes the properties and forms a pattern on a substrate.

Japanese Patent Application Laid-Open No. 9-127 discloses an example of a resin to be combined with a compound that generates an acid by photolysis.
Japanese Patent No. 698 discloses polyhydroxystyrene substituted with a specific acetal group and a t-butoxycarbonyloxy group, which can improve high sensitivity, high resolution, high heat resistance, and further improve the depth of focus characteristic. Are listed. However, there is still room for improvement in resolution,
The resolution was still lacking.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a positive photoresist composition which comprises:
In particular, by solving the problem of the performance improvement technology inherent in microphotofabrication using excimer laser light, high sensitivity, high resolving power, and excellent pattern profile are obtained for use of this short wavelength light source. Development of a resist composition. Among them, improvement of resolution (limit resolution) is a main object of the present invention.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a positive type chemically amplified resist composition has
The present inventors have found that the above-mentioned various objects of the present invention can be achieved by a combination of a specific constitution of a resin and a photobase generator, and have accomplished the present invention. That is, the present invention is achieved by a method having the following configuration.

(1) (a) a compound having a group decomposed by an acid represented by the following general formula (I), decomposed by the action of an acid to increase the solubility in an alkaline developer, (b) actinic ray Alternatively, a positive photoresist composition comprising: a compound which decomposes upon irradiation with radiation to generate an acid; and (c) a compound which decomposes upon irradiation with actinic rays or radiation to generate a base.

[0008]

Embedded image

In the formula, R ₁ represents a hydrogen atom or a methyl group. R ₂ represents a methyl group or an ethyl group, and R ₃ represents an alkyl group having 1 to 4 carbon atoms. (2) The compound (a) wherein the hydroxyl group in poly (p-hydroxystyrene) or a copolymer containing the same is substituted with a group represented by the general formula (I). The positive photoresist composition according to 1). (3) The positive resist composition as described in (1) or (2) above, which contains a compound in which a hydroxyl group of a phenolic compound having a molecular weight of 3000 or less is substituted with a group that decomposes under the action of an acid. (4) The positive resist composition according to any one of (1) to (3), further comprising an organic basic compound.

In a resist composition, a technique using a photobase generator instead of a photoacid generator has been proposed.
For example, JP-A-4-330444, "Polymer",
46, No. 6, pages 242 to 248 (1997), and U.S. Pat. No. 5,627,101. These photobase generators have been proposed for negative photoresists. In a positive photoresist composition, by using a photoacid generator and a photobase generator together with a resin having a specific structure, the inadequate resolution of a specific acid-decomposable group in the present invention is excellently resolved, and the sensitivity is also higher. We were able to hold on level. When the positive photoresist composition of the present invention is used as a resist for forming a contact hole, a contact hole with few defects can be formed, and the effects of the present invention can be particularly exhibited.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the compounds used in the present invention will be described in detail. (A) A compound having an acid-decomposable group represented by the above general formula (I), which is decomposed by the action of an acid to increase the solubility in an alkali developer will be described. Specific examples of the acid-decomposable group represented by the general formula (I) include, for example, 1-methoxyethoxy group, 1-ethoxyethoxy group, 1-n-propoxyethoxy group, 1-isopropoxyethoxy group,
1-n-butoxyethoxy group, 1-isobutoxyethoxy group, 1-t-butoxyethoxy group, 1- (1,1-dimethylethoxy) -1-methylethoxy group, 1-methoxy-1-methylethoxy group, 1-ethoxy-1-methylethoxy group, 1-n-propoxy-1-methylethoxy group, 1-isobutoxy-1-methylethoxy group, 1-methoxy-n-propoxy group, 1-ethoxy-n-propoxy group, etc. Is mentioned. Among them, a 1-ethoxyethoxy group, a 1-isobutoxyethoxy group, a 1-t-butoxyethoxy group, and a 1-methoxy-n-propoxy group are particularly preferred because sensitivity and resolution are improved in a well-balanced manner.

The above-mentioned compound (a) includes two kinds of alkali-soluble resins (polymer-type dissolution inhibiting compounds) containing the acid-decomposable group of the general formula (I) and non-polymeric dissolution-inhibiting compounds. In the present invention, these polymer-type dissolution inhibiting compounds and non-polymer-type dissolution inhibiting compounds may be used in combination. When only the non-polymeric dissolution inhibiting compound is contained as the compound of the general formula (I), it is preferable to contain an alkali-soluble resin as the binder.

The polymer-type dissolution-inhibiting compound containing an acid-decomposable group represented by the general formula (I) is a compound having a molecular weight distribution obtained by polymerizing a monomer. A compound having an introduced structure and becoming alkali-soluble by the action of an acid. The non-polymeric dissolution inhibiting compound having an acid-decomposable group represented by the general formula (I) includes 3
It is a compound having a certain molecular weight of 000 or less, a compound having a single structure and a structure in which an acid-decomposable group of the general formula (I) is introduced, and being alkali-soluble by the action of an acid.

(A) -1 Polymeric dissolution-inhibiting compound containing an acid-decomposable group of the general formula (I) The polymer-type dissolution-inhibiting compound used in the present invention is prepared by adding an acid-decomposable group of the general formula (I) to a resin. Is a resin having a main chain or a side chain, or both a main chain and a side chain. Of these,
Resins having an acid-decomposable group of the formula (I) in the side chain are more preferred. The polymer-type dissolution inhibiting compound containing an acid-decomposable group represented by the general formula (I) includes poly-p-hydroxystyrene partially containing a structural unit protected by the general formula (I) or a copolymer containing the same. Is more preferable, and more preferably, the resin is a resin having a crosslinked structure. More preferably, such a resin is represented by the following general formula (a):
(B) a resin containing a repeating structural unit represented by (c), and a resin having a crosslinked structure with a linking group represented by general formula (d) in the repeating structural unit represented by general formula (c), or And a resin represented by the following general formula (e).

[0015]

Embedded image

In the formulas (a), (b), (c) and (d), R
_{1 to} R ₃ are as defined above. R _X represents a hydrogen atom or a methyl group; Rd, Re, Rg, and Rh each independently represent a hydrogen atom, a linear alkyl group having 1 to 8 carbon atoms,
Eight branched alkyl groups and cyclic alkyl groups having 3 to 6 carbon atoms (provided that Rd, Re, Rg, and Rh do not simultaneously represent a hydrogen atom. Further, Rd and Re, or Rg and Rh are each a bond. May form a ring.).

Rf represents a linear alkylene group having 1 to 6 carbon atoms, a branched alkylene group having 3 to 8 carbon atoms,
Cyclic alkylene groups, or

[0018]

Embedded image

## EQU1 ## Here, Ri and Rj each independently represent a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms, or a cyclic alkyl group having 3 to 6 carbon atoms.

[0020]

Embedded image

In the formula (e), R _X , R ₁ , R ₂ and R ₃ are
It is the same as the above. l + m = 100, 0.10 ≦ m / (l + m) ≦ 0.95.

In the above general formulas (a) to (d) and (e), the straight-chain alkyl having 1 to 8 carbon atoms includes methyl, ethyl, propyl, butyl, pentyl, A hexyl group, a heptyl group, and an octyl group are exemplified, and a linear alkyl group having 1 to 4 carbon atoms is particularly preferable. Examples of the branched alkyl group having 3 to 8 carbon atoms include isopropyl, isobutyl, t-butyl, neopentyl, 2-methylbutyl, 3-methylpentyl, 2-ethylbutyl, and 1,1-dimethyl- Examples thereof include a 2-methylpropyl group, a 1-methylhexyl group, a 2-ethylpentyl group, a 2-ethyl-3-methylbutyl group, and a 2-ethylhexyl group, and a branched alkyl group having 3 to 5 carbon atoms is particularly preferable. . Examples of the cyclic alkyl group having 3 to 6 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group, and among them, a cyclopentyl group and a cyclohexyl group are preferable.
Rd and Re or Rg and Rh may be bonded to each other to form a ring, and examples of the ring include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.

In Rf, a linear alkylene group having 1 to 6 carbon atoms, a branched alkylene group having 3 to 8 carbon atoms,
As the 6 to 6 cyclic alkylene groups, each having the above carbon number of 1
Examples thereof include divalent groups corresponding to the specific examples described above for a straight-chain alkyl group having 6 to 6 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms, and a cyclic alkyl group having 3 to 6 carbon atoms.

The molar ratio of the repeating structural units represented by formulas (a), (b) and (c) is 0.01 ≦ formula (b)
/ Expression [(a) + (b) + (c)] ≦ 0.70, preferably 0.05 ≦ expression (b) / expression [(a) + (b) +
(C)] ≦ 0.50, and 0 ≦ formula (c) / [formula (a)
+ (B) + (c)] ≦ 0.20, preferably 0.005
≦ expression (c) / expression [(a) + (b) + (c)] ≦ 0.1
5, particularly preferably 0.007 ≦ formula (c) / formula [(a)
+ (B) + (c)] ≦ 0.10.

A repeating structural unit represented by the general formula (a), (b) or (c), wherein the repeating structural unit represented by the general formula (c) is linked by the general formula (d) The weight average molecular weight of the resin having a crosslinked structure by a group is preferably 5,000 to 100,000, and more preferably 7000 to 50,000. The weight average molecular weight of the resin represented by the general formula (e) is 5,000 to 1,000.
00, more preferably 7000 to 10,000
0.

In the present invention, a resin represented by the general formula (e) and / or a repeating structural unit represented by the general formulas (a), (b) and (c), The amount of the resin having a cross-linked structure formed by the linking group represented by the general formula (d) in the repeating structural unit represented by the general formula (d) in the resist composition is from 20% by weight to 9% by weight based on the total solid content.
It is 9% by weight, preferably 40% to 97% by weight.

In the polymer type dissolution inhibiting compound of the present invention, in addition to the acid-decomposable group represented by the above general formula (I),
It may contain another acid-decomposable group. Such other acid-decomposable groups include an alkoxycarbonyloxy group or an alkoxycarbonylmethoxy group. Among them, tert-butoxycarbonyloxy, sec-butoxycarbonyloxy, tert-butoxycarbonylmethoxy and sec-butoxycarbonyloxy are particularly preferred.
It is a structural unit having a c-butoxycarbonylmethoxy group as a protecting group. Specific examples of the polymer-type dissolution inhibiting compound in the present invention are shown below, but the present invention is not limited thereto. Further, in the following specific examples, k, l, m,
The proportions of n and p are determined by the above equations (a), (b) and (c).
The relationship is the same. The specific numerical values are shown for each compound in the synthesis examples.

[0028]

Embedded image

[0029]

Embedded image

[0030]

Embedded image

[0031]

Embedded image

[0032]

Embedded image

[0033]

Embedded image

(A) -2 Non-polymeric dissolution-inhibiting compound containing an acid-decomposable group of the general formula (I) In the present invention, the acid-decomposable group of the non-polymeric dissolution-inhibiting compound is represented by the general formula (I) Is an acid-decomposable group represented by However, various acid-decomposable groups other than the acid-decomposable group represented by the general formula (I) can also be used. Hereinafter, non-polymeric dissolution inhibiting compounds having an acid-decomposable group, including the acid-decomposable group of the general formula (I), which can be used in the present invention will be described.

The non-polymeric dissolution inhibiting compound used in the present invention has at least two groups which can be decomposed by an acid in its structure, and at the position where the distance between the acid-decomposable groups is the longest, At least 8 bonding atoms excluding decomposable groups
Compound. In the present invention, preferably, the non-polymeric dissolution-inhibiting compound has at least two groups capable of being decomposed by an acid in its structure, and at the position where the distance between the acid-decomposable groups is the longest, the acid-decomposable group A compound having at least 10, preferably at least 11, and more preferably at least 12 bonding atoms excluding the above, or a position where the distance between the acid-decomposable groups is the longest, having at least three acid-decomposable groups Is a compound having at least 9, preferably at least 10, and more preferably at least 11 bonding atoms excluding an acid-decomposable group.
The preferred upper limit of the number of the bonding atoms is 50, more preferably 30. In the present invention, when the non-polymer type dissolution inhibiting compound has three or more, preferably four or more acid-decomposable groups, and even if it has two acid-decomposable groups, the acid-decomposable groups are mutually present. If the distance is more than a certain distance, the dissolution inhibiting property with respect to the resin is remarkably improved.
In addition, the distance between the acid-decomposable groups in the present invention is represented by the number of via bond atoms excluding the acid-decomposable groups. For example, in the case of the following compounds (1) and (2), the distance between the acid-decomposable groups is
Each has 4 bonding atoms, and compound (3) has 1 bonding atom
There are two.

[0036]

Embedded image

The non-polymeric dissolution inhibiting compound of the present invention may have a plurality of acid-decomposable groups on one benzene ring, but preferably has one acid-decomposable group on one benzene ring.
It is a compound composed of a skeleton having two acid-decomposable groups. Further, the molecular weight of the non-polymeric acid-decomposable dissolution inhibiting compound of the present invention is 3,000 or less, preferably 500
~ 3,000, more preferably 1,000 ~ 2,500
It is.

In a preferred embodiment of the present invention, an acid
A group which can be decomposed by, ie, -COO-A⁰, -OB⁰
As a group containing a group, -R⁰-COO-A⁰Or -A
r-OB⁰The group shown by these is mentioned. Where A
⁰Is -C (R⁰¹) (R⁰²) (R⁰³), -Si (R⁰¹)
(R⁰²) (R ⁰³) Or -C (R⁰⁴) (R⁰⁵) -O-
R⁰⁶Represents a group. B⁰Is A⁰Or -CO-OA⁰Base
Show. R⁰¹, R⁰², R⁰³, R⁰⁴And R⁰⁵Are the same
May be different from each other, and may include a hydrogen atom, an alkyl group,
Represents a chloroalkyl, alkenyl, or aryl group
Then R⁰⁶Represents an alkyl group or an aryl group. However
Then R⁰¹~ R⁰³At least two are groups other than hydrogen atoms
And R⁰¹~ R⁰³, And R⁰⁴~ R⁰⁶Two of
The groups may combine to form a ring. R⁰Has a substituent
Divalent or higher aliphatic or aromatic hydrocarbons
Represents a group, -Ar- has a monocyclic or polycyclic substituent
And a divalent or higher aromatic group which may be present.

The alkyl group is preferably a group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group and a t-butyl group. Preferred are those having 3 to 10 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclohexyl group and adamantyl group, and alkenyl groups having 2 to 2 carbon atoms such as vinyl group, propenyl group, allyl group and butenyl group. Preferably, the aryl group has 6 to 1 carbon atoms such as phenyl, xylyl, toluyl, cumenyl, naphthyl and anthracenyl.
Four are preferred.

As the substituent, a hydroxyl group, a halogen atom (fluorine, chlorine, bromine, iodine), a nitro group, a cyano group, the above-mentioned alkyl group, methoxy group, ethoxy group, hydroxyethoxy group, propoxy group, hydroxypropoxy group Alkoxy groups such as groups, n-butoxy group, isobutoxy group, sec-butoxy group, t-butoxy group, alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group, aralkyl groups such as benzyl group, phenethyl group and cumyl group, Aralkyloxy group, formyl group, acetyl group, butyryl group, benzoyl group, cyanyl group, acyl group such as valeryl group, acyloxy group such as butyryloxy group, the above alkenyl group, vinyloxy group, propenyloxy group, allyloxy group, butenyloxy group Alkenyloxy groups such as Serial aryl group, an aryloxy group such as phenoxy group, and an aryloxycarbonyl group such as benzoyloxy group.

The acid-decomposable group is preferably a silyl ether group, a cumyl ester group, an acetal group, a tetrahydropyranyl ether group, an enol ether group, an enol ester group, a tertiary alkyl ether group, or a tertiary alkyl group. Alkyl ester groups, tertiary alkyl carbonate groups and the like. In the present invention, the acid-decomposable group contained in the non-polymeric acid-decomposable dissolution inhibiting compound is more preferably an acetal group, a tertiary alkyl ester group, a tertiary alkyl carbonate group, a cumyl ester group, a tetrahydropyranyl ether. Group.

The non-polymer type dissolution inhibiting compound is preferably a compound described in JP-A-1-289946 and JP-A-1-28.
9947, JP-A-2-2560, JP-A-3-128
959, JP-A-3-158855, JP-A-3-17
9353, JP-A-3-191351, JP-A-3-2
00251, JP-A-3-200252, JP-A-3-20052
No. 200253, JP-A-3-200254, JP-A-3
JP-A-200255, JP-A-3-259149, JP-A-3-279958, JP-A-3-279959, JP-A-4-1650, JP-A-4-1651, and JP-A-4-165
No. 11260, JP-A-4-12356, JP-A-4-1
No. 2357, Japanese Patent Application No. 3-33229, Japanese Patent Application No. 3-23
No. 0790, Japanese Patent Application No. 3-320438, Japanese Patent Application No. 4-2
No. 5157, Japanese Patent Application No. 4-52732, Japanese Patent Application No. 4-10
3215, Japanese Patent Application No. 4-104542, Japanese Patent Application No. 4-1
No. 07885, Japanese Patent Application No. 4-107889, 4-15
A part or all of the phenolic OH group of the polyhydroxy compound described in the specification such as No. 2195 or the like is bonded by the above-mentioned group, -R ⁰ -COO-A ⁰ or B ⁰ group,
Includes protected compounds.

More preferably, JP-A-1-289946.
JP-A-3-128959, JP-A-3-15885
5, JP-A-3-179353, JP-A-3-2002
No. 51, JP-A-3-200252, JP-A-3-200
255, JP-A-3-259149, JP-A-3-27
9958, JP-A-4-1650, JP-A-4-112
No. 60, JP-A-4-12356, JP-A-4-1235
7, Japanese Patent Application No. 4-25157, Japanese Patent Application No. 4-10321
No. 5, Japanese Patent Application No. 4-104542, Japanese Patent Application No. 4-1078
No. 85, Japanese Patent Application Nos. 4-107889 and 4-15219
No. 5 using the polyhydroxy compound described in the specification.

More specifically, general formulas [I] to [XV]
The compound represented by I] is mentioned.

[0045]

Embedded image

[0046]

Embedded image

[0047]

Embedded image

[0048]

Embedded image

R ¹⁰¹ , R ¹⁰² , R ¹⁰⁸ , R ¹³⁰ may be the same or different, and represent a hydrogen atom, —R ⁰ —COO—C
( ^R01 ) ( ^R02 ) ( ^R03 ) or -CO-OC ( ^R01 )
^{(R 0 2) (R 03} ), provided that the definition of R ^0, R ^01, R ⁰² and R ⁰³ are as defined above. R ¹⁰⁰ : -CO-, -COO-, -NHCONH-,-
NHCOO-, -O-, -S-, -SO-, -SO
_2- , -SO _3- , or

[0050]

Embedded image

[0051] Here, G = 2 to 6, provided that at least one alkyl group of R ^0.99, R ¹⁵¹ when the ^{G = 2, R 150, R} 151: may be the same or different, a hydrogen atom, an alkyl Group, alkoxy group, -OH, -COOH,
-CN, halogen atom, -R ¹⁵² -COOR ^{15 3} or ^{-R 154 -OH, R 152, R} 154: an alkylene group, R ^153: a hydrogen atom, an alkyl group, an aryl group or an aralkyl group,, R ^99, R ¹⁰³ To R ¹⁰⁷ , R ¹⁰⁹ , R ^{111 to} R ¹¹⁸ , R
^{121 to} R ¹²³ , R ^{128 to} R ¹²⁹ , R ^{131 to} R ¹³⁴ , R
^{138 to} R ¹⁴¹ and R ¹⁴³ may be the same or different and include a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, an aryloxy group, an aralkyl group, an aralkyloxy group, a halogen atom, nitro Group, carboxyl group, cyano group, or -N ( ^R155 ) ( ^R156 ) ( ^R155 , ^R156 : H, alkyl group, or aryl group) ^R110 : single bond, alkylene group, or

[0052]

Embedded image

R ¹⁵⁷ and R ¹⁵⁹ may be the same or different, and represent a single bond, an alkylene group, —O—, —S—, —CO
— Or a carboxyl group, R ¹⁵⁸ : a hydrogen atom, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, a nitro group, a hydroxyl group, a cyano group, or a carboxyl group, provided that the hydroxyl group is an acid-decomposable group (for example, t-butoxycarbonylmethyl group, tetrahydropyranyl group, 1-ethoxy-1-ethyl group,
(1-t-butoxy-1-ethyl group). R ^119, R ^120: may be the same or different, a methylene group, a lower alkyl-substituted methylene group, halomethylene group or a haloalkyl group, with the proviso The lower alkyl group herein refers to an alkyl group having 1 to 4 carbon atoms, R ¹²⁴ To R ¹²⁷ : identical or different, a hydrogen atom or an alkyl group; R ^{135 to} R ¹³⁷ : identical or different, a hydrogen atom,
An alkyl group, an alkoxy group, an acyl group, or an acyloxy group, R ¹⁴² : a hydrogen atom, —R ⁰ —COO—C (R ⁰¹ )
( ^R02 ) ( ^R03 ) or -CO-OC ( ^R01 ) ( ^R02 )
(R ⁰³ ), or

[0054]

Embedded image

R ¹⁴⁴ and R ¹⁴⁵ may be the same or different and represent a hydrogen atom, a lower alkyl group, a lower haloalkyl group,
Or an aryl group, R ^{146 to} R ¹⁴⁹ : may be the same or different, and may be hydrogen, hydroxyl, halogen, nitro, cyano, carbonyl, alkyl, alkoxy, alkoxycarbonyl, aralkyl, aralkyloxy A group, an acyl group, an acyloxy group, an alkenyl group, an alkenyloxy group, an aryl group, an aryloxy group, or an aryloxycarbonyl group, provided that the four substituents having the same symbols do not have to be the same group. : —CO— or —SO ₂ —, Z, B: single bond or —O—, A: methylene group, lower alkyl-substituted methylene group, halomethylene group, or haloalkyl group; E: single bond or oxymethylene group , A to z, a1 to y1: when plural, the groups in () may be the same or different; a to q, s, t, v, g1 to i1, k1 m1, o1, q1, s1, u1: 0 or an integer of 1 to 5, r, u, w, x, y, z, a1~f1, p1, r1, t1, v1~x1: 0 or 1
An integer of 4, j1, n1, z1, a2, b2, c2, d2: an integer of 0 or 1 to 3, z1, a
2, at least one of c2, d2 is 1 or more, y1: an integer of 3 to 8, (a + b), (e + f + g), (k + l + m), (q + r + s ), (w + x + y), (c1 + d1), (g1 +
h1 + i1 + j1), (o1 + p1), (s1 + t1) ≧ 2, (j1 + n1) ≦ 3, (r + u), (w + z), (x + a1), (y + b1), (c1 + e1), (d1 + f1), (p1 + r1),
(t1 + v1), (x1 + w1) ≦ 4, except for general formula [5] where (w +
z), (x + a1) ≦ 5, (a + c), (b + d), (e + h), (f + i), (g + j), (k + n), (l + o), (m + p), (q
+ t), (s + v), (g1 + k1), (h1 + l1), (i1 + m1), (o1 + q1), (s1 + u1)
≦ 5.

[0056]

Embedded image

[0057]

Embedded image

[0058]

Embedded image

[0059]

Embedded image

Specific examples of preferred compound skeletons are shown below.

[0061]

Embedded image

[0062]

Embedded image

[0063]

Embedded image

[0064]

Embedded image

[0065]

Embedded image

[0066]

Embedded image

[0067]

Embedded image

[0068]

Embedded image

[0069]

Embedded image

[0070]

Embedded image

[0071]

Embedded image

[0072]

Embedded image

[0073]

Embedded image

[0074]

Embedded image

[0075]

Embedded image

[0076]

Embedded image

[0077]

Embedded image

[0078]

Embedded image

[0079]

Embedded image

R in the compounds (1) to (63) is a hydrogen atom,

[0081]

Embedded image

Represents the following. However, at least two or three depending on the structure are groups other than hydrogen atoms, and each substituent R
Need not be the same group.

In the present invention, the amount of the non-polymeric dissolution inhibiting compound to be added is 3 to 50% by weight, preferably 5 to 5% by weight, based on the total weight of the photosensitive composition (excluding the solvent).
-40% by weight, more preferably 10-35% by weight.

In the positive photoresist composition of the present invention,
Is a polymer-type dissolution inhibiting compound, in addition to a few other
Use at least one resin partially protected with acid-decomposable groups
can do. Preferred groups that can be decomposed by acid
Is -COOA⁰, -OB⁰And these are
The group to be contained is -R⁰-COOA⁰Or -A_r-O
-B⁰The group shown by these is mentioned. Where A⁰Is -C
(R⁰¹) (R⁰²) (R⁰³), -Si (R⁰¹) (R⁰²)
(R ⁰³) Or -C (R⁰⁴) (R⁰⁵) -OR⁰⁶Base
Show. B⁰Is -A⁰Or -CO-OA⁰Indicates a group
(R⁰, R⁰¹~ R⁰⁶, And Ar are as defined below).

The acid-decomposable group is preferably a silyl ether group, cumyl ester group, tetrahydropyranyl ester group, enol ester group, tertiary alkyl ether group, tertiary alkyl ester group, tertiary alkyl group. And a carbonate group. More preferred are a tertiary alkyl ester group, a tertiary alkyl carbonate group and a cumyl ester group.

Resins having such an acid-decomposable group are disclosed in European Patent No. 2,485,853 and JP-A-2-25850.
No. 3,223,860, 4-251259, etc., an alkali-soluble resin is reacted with a precursor of an acid-decomposable group, or an acid-decomposable group is bonded thereto. It can be obtained by copolymerizing an alkali-soluble resin monomer with various monomers.

Specific examples of the resin having a group decomposable with an acid used in the present invention are shown below, but the present invention is not limited to these.

[0088]

Embedded image

[0089]

Embedded image

[0090]

Embedded image

[0091]

Embedded image

The content of acid-decomposable groups is determined by the number of acid-decomposable groups in the resin (B) and the number of alkali-soluble groups not protected by acid-decomposable groups (S). B /
It is represented by (B + S). The content is preferably 0.01 to
It is 0.70, more preferably 0.05 to 0.60, and still more preferably 0.05 to 0.50. B / (B + S)>
A value of 0.70 is not preferable because it causes film shrinkage after PEB, poor adhesion to the substrate, film reduction phenomenon and scum. On the other hand, B
If /(B+S)<0.01, it is not preferable because standing waves may remarkably remain on the pattern side wall.

The weight average molecular weight (Mw) of such a resin having a group decomposable with an acid is 2,000 to 200,0.
It is preferably in the range of 00. If it is less than 2,000, the film loss is large due to the development of the unexposed portion, and
If the ratio exceeds the above range, the dissolution rate of the alkali-soluble resin itself in alkali becomes slow, and the sensitivity is lowered. More preferably, it is in the range of 5,000 to 100,000, and still more preferably in the range of 8,000 to 50,000. Further, the degree of dispersion (Mw / Mn) is preferably 1.0 to 4.0.
0, more preferably 1.0 to 2.0, particularly preferably 1.0 to 1.6, and the smaller the degree of dispersion, the higher the heat resistance,
Image formability (pattern profile, defocus latitude, etc.) is improved. Here, the weight average molecular weight is defined as a polystyrene equivalent value of gel permeation chromatography.

These resins having a group decomposable with an acid may be used as a mixture of two or more kinds. The amount of these other resins that can be used in combination in the present invention is 50% by weight or less, preferably 30% by weight or less based on the total weight of the resist composition (excluding the solvent). Further, in order to adjust the alkali solubility, an alkali-soluble resin described below having no group decomposable with an acid may be mixed.

Alkali-soluble resin usable in the present invention In the present invention, a water-insoluble resin soluble in an aqueous alkali solution (hereinafter also referred to as an alkali-soluble resin) can be used. The alkali dissolution rate of the alkali-soluble resin was measured using a 0.261N tetramethylammonium hydroxide (TMAH) (23 ° C.) and was 20 ° /
Seconds or more are preferred. It is particularly preferably at least 200 ° / sec (Å is Angstroms).

Examples of the alkali-soluble resin used in the present invention include novolak resin, hydrogenated novolak resin, acetone-pyrogallol resin, o-polyhydroxystyrene, m-polyhydroxystyrene, p-polyhydroxystyrene, and hydrogenated polyhydroxy resin. Styrene, halogen or alkyl-substituted polyhydroxystyrene, hydroxystyrene-N-substituted maleimide copolymer, o /
p- and m / p-hydroxystyrene copolymers, partially O-alkylated compounds based on hydroxyl groups of polyhydroxystyrene (for example, 5 to 30 mol% of O-methylated products, O-
(1-methoxy) ethylated product, O- (1-ethoxy) ethylated product, O-2-tetrahydropyranylated product, O-
(T-butoxycarbonyl) methylated compound) or O
-Acylated products (e.g., 5 to 30 mol% o-acetylated product, O- (t-butoxy) carbonylated product, etc.), styrene-maleic anhydride copolymer, styrene-hydroxystyrene copolymer, α-methylstyrene -Hydroxystyrene copolymer, carboxyl group-containing methacrylic resin and derivatives thereof, but are not limited thereto.

Particularly preferred alkali-soluble resins are novolak resins and o-polyhydroxystyrene, m-polyhydroxystyrene, p-polyhydroxystyrene and copolymers thereof, alkyl-substituted polyhydroxystyrene, and a part of O-hydroxypolystyrene. Alkylated or O-acylated products, styrene-hydroxystyrene copolymers, and α-methylstyrene-hydroxystyrene copolymers. The novolak resin is obtained by subjecting a given monomer as a main component to addition condensation with an aldehyde in the presence of an acidic catalyst.

As the predetermined monomer, phenol, m
Cresols such as -cresol, p-cresol and o-cresol, xylenols such as 2,5-xylenol, 3,5-xylenol, 3,4-xylenol and 2,3-xylenol, m-ethylphenol, p- Alkylphenols such as ethylphenol, o-ethylphenol, pt-butylphenol, p-octylphenol, 2,3,5-trimethylphenol, p-methoxyphenol, m-methoxyphenol, 3,5-dimethoxyphenol, Alkoxyphenols such as -methoxy-4-methylphenol, m-ethoxyphenol, p-ethoxyphenol, m-propoxyphenol, p-propoxyphenol, m-butoxyphenol and p-butoxyphenol, 2-methyl-4-isopropyl Fenault Bis-alkylphenols etc., m
Hydroxychloro compounds such as -chlorophenol, p-chlorophenol, o-chlorophenol, dihydroxybiphenyl, bisphenol A, phenylphenol, resorcinol, and naphthol can be used alone or as a mixture of two or more, but are not limited thereto. It is not something to be done.

Examples of the aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-
Phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde, o -Methylbenzaldehyde, m-methylbenzaldehyde,
p-Methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde, furfural, chloroacetaldehyde and their acetal forms, for example, chloroacetaldehyde diethyl acetal, among which formaldehyde is used Is preferred. These aldehydes are used alone or in combination of two or more. As the acidic catalyst, hydrochloric acid, sulfuric acid, formic acid, acetic acid, oxalic acid and the like can be used.

The novolak resin thus obtained preferably has a weight average molecular weight in the range of 1,000 to 30,000. If it is less than 1,000, the film loss of the unexposed portion after development is large, and if it exceeds 30,000, the developing speed is reduced. Particularly preferred are 2,000-20,
000. In addition, the weight average molecular weight of the polyhydroxystyrene other than the novolak resin, its derivative, and the copolymer is 2,000 or more, preferably 5,000.
~ 200,000, more preferably 10,000-1000
00. Further, from the viewpoint of improving the heat resistance of the resist film, 25,000 or more is preferable. here,
The weight average molecular weight is defined as a value in terms of polystyrene by gel permeation chromatography. In the present invention, these alkali-soluble resins may be used as a mixture of two or more kinds. The amount of alkali-soluble resin used is
Based on the total weight of the resist composition (excluding solvent),
It is 0 to 50% by weight, preferably 0 to 30% by weight.

(B) Photoacid Generator The photoacid generator used in the present invention is a compound (photoacid generator) that decomposes upon irradiation with actinic rays or radiation to generate an acid. Specifically, the following compounds can be used as the photoacid generator.

In the present invention, the photoacid generator includes a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization,
A photo-decoloring agent, a photo-discoloring agent, or a known compound that generates an acid by light used in a micro resist or the like and a mixture thereof can be appropriately selected and used.

For example, SISchlesinger, Photogr.Sci.E
ng., 18,387 (1974), TSBal etal, Polymer, 21,423 (198
0) etc., U.S. Pat.No.4,069,055
No. 4,069,056, Re 27,992, JP-A-3-140,140
Salt, DCNecker etal, Macrom
olecules, 17, 2468 (1984), CSwen et al, Teh, Proc. Con
f.Rad.Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat.Nos. 4,069,055, 4,069,056, etc.
(1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent Nos. 104,143, 339,049, 410,201, JP-A-2-150,848, JP-A-2-296,514, etc. Iodonium salt, JVCrivello etal, Polymer J. 17, 73 (1985)
, JVCrivelloetal.J.Org.Chem., 43, 3055 (1978), W.
R. Watt et al, J. Polymer Sci., Polymer Chem. Ed., 22, 178
9 (1984), JVCrivello et al., Polymer Bull., 14, 279 (1
985), JVCrivello etal, Macromorecules, 14 (5), 1141
(1981), JVCrivello etal, J. PolymerSci., Polymer C
hem.Ed., 17, 2877 (1979), European Patent Nos. 370,693, 16
1,811, 410,201, 339,049, 233,567
Nos. 297,443 and 297,442; U.S. Pat.No.4,933,377
Nos. 3,902,114, 4,760,013, 4,734,444
No. 2,833,827, Dokoku Patent No. 2,904,626, No. 3,60
Nos. 4,580 and 3,604,581, etc.
JVCrivello etal, Macromorecules, 10 (6), 1307 (1977)
, JVCrivello etal, J. PolymerSci., Polymer Chem. E
d., 17,1047 (1979), etc., selenonium salts, CSWen
etal, Teh, Proc.Conf.Rad.Curing ASIA, p478 Tokyo, Oct
(1988) etc., onium salts such as arsonium salts, U.S. Pat.No. 3,905,815, JP-B-46-4605, JP-A-48-3
No. 6281, JP-A-55-32070, JP-A-60-239736, JP-A-61-169835, JP-A-61-169837, JP-A-62-58241
No., JP-A-62-212401, JP-A-63-70243, JP-A-63
-298339, K. Meier et.
al, J. Rad. Curing, 13 (4), 26 (1986), TPGill et al, Ino
rg.Chem., 19,3007 (1980), D.Astruc, Acc.Chem.Res., 19
(12), 377 (1896), organometallic / organic halides described in JP-A-2-14145, S. Hayase et al., J. PolymerSc
i., 25,753 (1987), E.Reichmanis et al., J.Pholymer Sc
i., Polymer Chem. Ed., 23, 1 (1985), QQ Zhu et al., J. Pho
tochem., 36, 85, 39, 317 (1987), B. Amit etal, Tetrahedro
n Lett., (24) 2205 (1973), DHR Barton et al., J. Chem So
c., 3571 (1965), PMCollins et al., J. Chem.SoC., Perkin
I, 1695 (1975), M. Rudinstein et al., Tetrahedron Lett.,
(17), 1445 (1975), JWWalker etal J. Am. Chem. Soc., 11
0,7170 (1988), SCBusman et al., J. Imaging Technol., 1
1 (4), 191 (1985), HMHoulihan et al, Macormolecules, 2
1,2001 (1988), PMCollins et al., J. Chem. Soc., Chem. Com
mun., 532 (1972), S. Hayase et al, Macromolecules, 18, 179.
9 (1985), E. Reichmanis et al., J. Electrochem. Soc., Soli
d State Sci.Technol., 130 (6), FMHoulihan et al, Mac
romolcules, 21, 2001 (1988), European Patent No. 0290,750, ibid.
46,083, 156,535, 271,851, 0,388,343
Nos., U.S. Pat.Nos. 3,901,710 and 4,181,531,
No. 60-198538, JP-A-53-133022, etc., a photoacid generator having an o-nitrobenzyl-type protecting group, M. TUNOOKA e
tal, Polymer Preprints Japan, 35 (8), G. Berner et al., J.
Rad.Curing, 13 (4), WJMijs etal, Coating Technol., 5
5 (697), 45 (1983), Akzo, H. Adachi et al, Polymer Prep
rints, Japan, 37 (3), European Patent Nos. 0199,672 and 84515
No. 044,115, No. 618,564, No. 0101,122, U.S. Pat.Nos. 4,371,605 and 4,431,774, JP-A-64-18143
Compounds which generate sulfonic acid by photodecomposition represented by iminosulfonate described in JP-A-2-245756, Japanese Patent Application No. 3-140109, etc., described in JP-A-61-166544, etc. Disulfone compounds can be mentioned.

Further, a group which generates an acid by these lights,
Alternatively, a compound having a compound introduced into a main chain or a side chain of a polymer, for example, MEWoodhouse et al., J. Am. Chem.
c., 104, 5586 (1982), SPPappas et al, J. Imaging Sc
i., 30 (5), 218 (1986), S. Kondoetal, Makromol.Chem., Ra
pid Commun., 9,625 (1988), Y.Yamada et al., Makromol.C
hem., 152, 153, 163 (1972), JVCrivello etal, J. Polym
erSci., Polymer Chem. Ed., 17,3845 (1979), U.S. Patent No. 3,849,137, Dokoku Patent No. 3,914,407, JP-A-63-266.
No. 53, JP-A-55-164824, JP-A-62-69263, JP-A-Showa
63-146038, JP-A-63-163452, JP-A-62-153853
And the compounds described in JP-A-63-146029 and the like can be used.

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

Among the compounds capable of decomposing upon irradiation with actinic rays or radiation to generate an acid, those which are particularly effectively used are described below. (1) The following general formula (PAG) substituted with a trihalomethyl group
The oxazole derivative represented by 1) or the general formula (PA)
An S-triazine derivative represented by G2).

[0107]

Embedded image

In the formula, R ²⁰¹ is a substituted or unsubstituted aryl group or alkenyl group, and R ²⁰² is a substituted or unsubstituted aryl group, alkenyl group, alkyl group, —C (Y) ₃
Show Y represents a chlorine atom or a bromine atom. Specific examples include the following compounds, but the present invention is not limited thereto.

[0109]

Embedded image

[0110]

Embedded image

[0111]

Embedded image

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

[0113]

Embedded image

In the formula, Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. Here, preferred 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,
And mercapto groups and halogen atoms.

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, 1 to 8 carbon atoms
And substituted derivatives thereof. Preferred substituents are those having 1 to 8 carbon atoms for the aryl group.
And an alkyl group having 1 to 8 carbon atoms, a nitro group, a carboxyl group, a hydroxy group and a halogen atom. The alkyl group is an alkoxy group having 1 to 8 carbon atoms, a carboxyl group or an alkoxycarbonyl group. is there.

[0116] Z ^- represents a counter anion, CF ₃ SO ₃ ^-
And the like, such as perfluoroalkanesulfonic acid anions and pentafluorobenzenesulfonic acid anions.

Further, two of R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ and Ar ¹ and Ar ² may be bonded through a single bond or a substituent.

Specific examples include the following compounds, but are not limited thereto.

[0119]

Embedded image

[0120]

Embedded image

[0121]

Embedded image

[0122]

Embedded image

[0123]

Embedded image

[0124]

Embedded image

[0125]

Embedded image

[0126]

Embedded image

[0127]

Embedded image

[0128]

Embedded image

[0129]

Embedded image

The above onium salts represented by the general formulas (PAG3) and (PAG4) are known, for example, JWKnapcz
yk etal, J. Am. Chem. Soc., 91, 145 (1969), ALMaycoke
tal, J. Org.Chem., 35, 2532, (1970), E. Goethas et al, Bu
ll.Soc.Chem.Belg., 73,546, (1964), HM Leicester,
J. Ame. Chem. Soc., 51, 3587 (1929), JVCrivello etal,
J. Polym. Chem. Ed., 18,2677 (1980), U.S. Pat.
It can be synthesized by the methods described in JP-A Nos. 8 and 4,247,473 and JP-A-53-101,331.

Among the onium salts represented by formulas (PAG3) and (PAG4), compounds represented by the following formula (1) or (2) are preferable.

[0132]

Embedded image

In the formula, R _{4 to} R ₈ each represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a hydroxy group, a halogen atom, or an —S—R ₉ group. R ₉ represents an alkyl group or an aryl group. X ⁻ represents an anion of benzenesulfonic acid, naphthalenesulfonic acid or anthracenesulfonic acid having 3 or more substituents having 1 carbon atom or having a substituent having 4 or more carbon atoms in all the substituents. .

In the formulas (1) and (2), R _{4 to} R ₉
The alkyl group of which may have a substituent includes those having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group and a t-butyl group. No. Examples of the cycloalkyl group include those having 3 to 8 carbon atoms such as a cyclopropyl group, a cyclopentyl group and a cyclohexyl group which may have a substituent. As the alkoxy group, a methoxy group, an ethoxy group,
Those having 1 to 4 carbon atoms such as a hydroxyethoxy group, a propoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group and a t-butoxy group are exemplified. As the halogen atom, a fluorine atom, a chlorine atom, a bromine atom,
An iodine atom can be mentioned. As the aryl group,
Examples thereof include those having 6 to 14 carbon atoms which may have a substituent such as a phenyl group, a tolyl group, a methoxyphenyl group, and a naphthyl group.

The substituent is preferably an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom or an iodine atom), an aryl group having 6 to 10 carbon atoms, or an alkenyl having 2 to 6 carbon atoms. Group, cyano group, hydroxy group,
Examples thereof include a carboxy group, an alkoxycarbonyl group, and a nitro group. The sulfonium or iodonium compound represented by the general formula (1) or (2) used in the present invention is a benzenesulfonic acid, a naphthalenesulfonic acid or an anthracenesulfone substituted with an alkyl group or an alkoxy group as a counter anion, X ^−. Acid anions are preferred. The alkyl or alkoxy substituent has three or more substituents having one carbon atom, or the sum of the carbon atoms of all the substituents is four or more.

[0136] In addition, X ^- in the aromatic sulfonic acid represented by, in addition to the above specific substituent, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), C6-10
It may contain as substituents aryl groups, cyano groups, sulfide groups, hydroxy groups, carboxy groups, nitro groups and the like. Counter anion, X ^- as, preferably branched or cyclic carbon number of 8 or more, more or preferably at least 1 or more 10 or more alkyl or alkoxy groups, linear, carbon branched or cyclic Benzenesulfonic acid, naphthalene sulfone having at least two or more alkyl groups or alkoxy groups of 4 to 7, or having at least three linear or branched alkyl or alkoxy groups having 1 to 3 carbon atoms It has an anion of acid or anthracene sulfonic acid. This reduces the diffusivity of the acid (benzenesulfonic acid, naphthalenesulfonic acid or anthracenesulfonic acid having the above group) generated after exposure, and improves the solvent solubility of the sulfonium or iodonium compound. In particular, from the viewpoint of reducing the diffusivity, a branched or cyclic alkyl group or alkoxy group is more preferable as the above group than a linear alkyl group or alkoxy group. When the number of the above groups is one, the difference in diffusivity between a straight chain and a branched or cyclic one becomes more remarkable.

C 8 or more, preferably C 8 to C 2
Examples of the zero alkyl group include a branched or cyclic octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group,
Examples include a tridecyl group, a tetradecyl group, and an octadecyl group. 8 or more carbon atoms, preferably 8 to 20 carbon atoms
Examples of the alkoxy group include a branched or cyclic octyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, a dodecyloxy group, a tridecyloxy group,
Examples include a tetradecyloxy group and an octadecyloxy group. Examples of the alkyl group having 4 to 7 carbon atoms include a linear, branched, or cyclic butyl group, a pentyl group, a hexyl group, and a heptyl group. Examples of the alkoxy group having 4 to 7 carbon atoms include a linear, branched, or cyclic butoxy group, a pentyloxy group, a hexyloxy group, and a heptyloxy group. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Examples of the alkoxy group having 1 to 3 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, and an isopropoxy group.

[0138] Further, similar to the above, X ^- Aromatic sulfonic acid represented by, in addition to the above specific substituent, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), 6 carbon atoms It may contain 10 aryl groups, cyano groups, sulfide groups, hydroxy groups, carboxy groups, nitro groups and the like as substituents. Hereinafter, these equations (1),
Specific examples of the compound represented by (2) include (I-1) to (I
-69) and (II-1) to (II-53), but are not limited thereto.

[0139]

Embedded image

[0140]

Embedded image

[0141]

Embedded image

[0142]

Embedded image

[0143]

Embedded image

[0144]

Embedded image

[0145]

Embedded image

[0146]

Embedded image

[0147]

Embedded image

[0148]

Embedded image

[0149]

Embedded image

[0150]

Embedded image

[0151]

Embedded image

[0152]

Embedded image

[0153]

Embedded image

[0154]

Embedded image

[0155]

Embedded image

In the specific examples, n is linear, s is secondary, t
Represents tertiary and i represents branching. General formula (1),
Compounds represented by (2), for example the corresponding Cl ^- salt and (formula (1), (X 2) ^- compounds substituted with ^- the Cl), X ^- Y ⁺ in the compound represented by (X ^- Is the same as in the general formulas (1) and (2), and Y ⁺ is H ⁺ , Na ⁺ , K
⁺ , NH ₄ ⁺ , N (CH ₃ ) ₄ ^{+ and the} like. )
Can be synthesized by salt exchange in an aqueous solution.

(3) Disulfone derivatives represented by the following formula (PAG5) or iminosulfonate derivatives represented by the following formula (PAG6).

[0158]

Embedded image

In the formula, Ar^Three, Ar^FourAre each independently substituted
Or an unsubstituted aryl group. R ²⁰⁶Is replaced or
Indicates an unsubstituted alkyl group or aryl group. A is a substitution
Or unsubstituted alkylene, alkenylene, arylene
Shows a substituent group. Specific examples include the compounds shown below.
However, the present invention is not limited to these.

[0160]

Embedded image

[0161]

Embedded image

[0162]

Embedded image

[0163]

Embedded image

[0164]

Embedded image

The amount of the photoacid generator added to the composition is preferably 0.05% by weight to 15% by weight, more preferably 0.1% to 1% by weight, based on the total weight of the composition (excluding the solvent).
0% by weight. (C) Compound that decomposes upon irradiation with actinic rays or radiation to generate a base In the present invention, the photobase generator is defined as UV, Deep-U
V, a compound that generates a base by irradiation with an active light beam such as an excimer laser beam, an electron beam, an X-ray and an ion beam. The photobase generator itself is generally neutral and generates a base (eg, an organic base such as an amine or hydroxide ion) by a photoreaction.

The photobase generator according to the present invention is disclosed in
No. 330444, “Polymer” p242-248, 4
Volume 6, Issue 6 (1997) or US-5,627,0
Those described in No. 10 are preferably used. However, the function is not particularly limited as long as a base is generated by irradiation with actinic rays. Preferred organic compound-based photobase generators in the present invention include triphenylmethanol, photoactive carbamates such as benzyl carbamate and benzoin carbamate, O-carbamoylhydroxylamide, O-carbamoyloxime, aromatic sulfonamide, alpha-lactam, N- (2
Examples include amides such as (allylethynyl) amide and other amides and oxime esters.

The photobase generator of the present invention is more preferably represented by any one of the following formulas (PBG-1) to (PBG-
It is a compound represented by 7). O-carbamoylhydroxylamine represented by the general formula (PBG-1) R ₁₀ R ₁₁ OC (＝ O) NR ₁₂ R ₁₃ wherein R ₁₀ and R ₁₁ may be the same or different, and include an alkyl group and an aryl group. , An acyl group, R ₁₂ represents a hydrogen atom, an alkyl group, and R ₁₃ represents an alkyl group or an aryl group. O-carbamoyl oxime represented by the general formula (PBG-2) R ₁₄ R ₁₅ C (＝ N) OC (＝ O) NR ₁₆ R ₁₇ R ₁₄ and R ₁₅ may be the same or different, and a hydrogen atom, An alkyl group, an aryl group, R ₁₆ represents an alkyl group or an aryl group, and R ₁₇ represents a hydrogen atom or an alkyl group. A sulfonamide represented by the general formula (PBG-3): ArS (= O) NR ₁₈ R ₁₉ Ar is an aryl group, R ₁₈ is a hydrogen atom or an alkyl group,
R ₁₉ represents an alkyl group or an aryl group. Alpha-lactam represented by the general formula (PBG-4)

[0168]

Embedded image

R ₂₀ is an alkyl group or an aryl group, R ₂₁
Represents an alkyl group or an aryl group. N- (2-allylethynyl) amide represented by the general formula (PBG-5), or formanilide or another aryl-substituted amide R ₂₂ C (＝ O) N (R ₂₃ ) CH ＝ CHAr R ₂₂ is an alkyl group Or, an aryl group and R ₂₃ represent an alkyl group, and Ar has the same meaning as described above. Oxime ester represented by the general formula (PBG-6) CH ₃ R ₂₄ C (（N) O (（O) CCR ₂₅ R ₂₆ R ₂₇ R ₂₄ is an alkyl group or an aryl group, R ₂₅ and R ₂₆ are a hydrogen atom or The alkyl group and R ₂₇ represent an alkyl group or an aryl group.

In the above, preferred aryl groups are unsubstituted or substituted phenyl groups. Preferred alkyl groups are linear, branched or cyclic, having 1 to 15 carbon atoms, particularly preferably having 1 to 6 carbon atoms, and having a substituent in the middle of the alkyl chain. Is also good. Here, preferred substituents are a halogen atom,
An aryl group and an alkyl group. As the acyl group,-
A group represented by C (= O) R is exemplified, wherein R represents an alkyl group or an aryl group, and preferred examples thereof include those described above, and preferred acyl groups include 1 to 10 carbon atoms. Is an acyl group.

Particularly preferably, 2-hydroxy-2-phenylacetophenone N-cyclohexyl carbamate,
O-nitrobenzyl N-cyclohexyl carbamate,
N-cyclohexyl-2-naphthalenesulfonamide,
3,5-dimethoxybenzyl N-cyclohexyl carbamate, N-cyclohexyl p-toluenesulfonamide and dibensoin isophorone dicarbamate, oxime ester.

A triphenylmethanol compound represented by the general formula (PBG-7)

[0173]

Embedded image

R ₂₈ , R ₂₉ and R ₃₀ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, a phenyl group or an alkoxy group. Here, examples of the alkyl group include groups having up to 5 carbon atoms such as a methyl group, an ethyl group, and a propyl group. Examples of the alkenyl group include a vinyl group and a propylenyl group, and examples of the alkynyl group include an acetylenyl group. The phenyl group may further have a substituent. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group.

Specific examples of the compound represented by formula (PBG-7) include, for example, triphenylmethanol, tri (4-chlorophenyl) methanol, tri (4
-Methoxyphenyl) methanol, tri (4-tert)
-Butoxyphenyl) methanol, (4-methylphenyl) methanol, tri (4-isopropenylphenyl)
Methanol, di (4-methoxyphenyl) -phenylmethanol, di (4-methoxyphenyl) chlorophenylmethanol and the like can be mentioned. These compounds can be obtained by a known general method, for example, by reacting a corresponding benzophenone derivative with a Grignard compound.

Also, J. Coatings Tech., 62, 786, 63-67 (Ju
ly 1990), a metal complex such as a cobalt (III) complex is also suitably used as a photobase generator.

In the present invention, particularly preferred examples of the photobase generator include those represented by formula (PBG-
4) or a compound represented by (PBG-7).
In the present invention, the amount of the photobase generator added to the composition is based on the total weight of the composition (excluding the solvent).
It is preferably 0.01% by weight to 10% by weight, more preferably 0.01% by weight to 5% by weight, and still more preferably 0.01% by weight.
% By weight to 2% by weight.

Other Components Used in the Photoresist Composition of the Present Invention The photosensitive composition of the present invention may further contain, if necessary,
Compounds, organic chlorine compounds, dyes, pigments, plasticizers,
It may contain a surfactant, a photosensitizer, a compound having two or more phenolic OH groups for promoting solubility in a developer, and the like.

Phenolic Compounds The compounds having two or more phenolic OH groups which can be used in the present invention are preferably phenol compounds having a molecular weight of 1,000 or less. Further, it is necessary to have at least two phenolic hydroxyl groups in the molecule.
If it exceeds 0, the effect of improving the development latitude is lost. Further, the ratio of the phenolic hydroxyl group to the aromatic ring is 0.5
If it is less than 3, the film thickness dependency is large, and the development latitude tends to be narrow. If this ratio exceeds 1.4, the stability of the composition deteriorates, and it becomes difficult to obtain high resolution and good film thickness dependency, which is not preferable.

The preferable addition amount of the phenol compound is 0 to 50% by weight, more preferably 0 to 30% by weight, based on the total amount of the resin. An addition amount exceeding 50% by weight is not preferable because new development defects such as development residue deterioration and pattern deformation during development occur.

Such a phenol compound having a molecular weight of 1000 or less can be prepared by those skilled in the art by referring to the methods described in, for example, JP-A-4-122938, JP-A-2-28531, US Pat. No. 4,916,210, and EP 219294. It can be easily synthesized at Specific examples of the phenol compound are shown below, but the compounds that can be used in the present invention are not limited to these.

Resorcin, phloroglucin, 2, 3, 4
-Trihydroxybenzophenone, 2,3,4,4'-
Tetrahydroxybenzophenone, 2,3,4,3 ',
4 ', 5'-hexahydroxybenzophenone, acetone-pyrogallol condensation resin, fluoroglucoside,
4,2 ', 4'-biphenyltetrol, 4,4'-thiobis (1,3-dihydroxy) benzene, 2,2',
4,4'-tetrahydroxydiphenyl ether, 2,
2 ', 4,4'-tetrahydroxydiphenylsulfoxide, 2,2', 4,4'-tetrahydroxydiphenylsulfone, tris (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) Cyclohexane, 4,4- (α-methylbenzylidene) bisphenol, α, α ′, α ″ -tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene,
α, α ', α "-tris (4-hydroxyphenyl)-
1-ethyl-4-isopropylbenzene, 1,2,2-
Tris (hydroxyphenyl) propane, 1,1,2-
Tris (3,5-dimethyl-4-hydroxyphenyl)
Propane, 2,2,5,5-tetrakis (4-hydroxyphenyl) hexane, 1,2-tetrakis (4-hydroxyphenyl) ethane, 1,1,3-tris (hydroxyphenyl) butane, para [α, α , Α ', α'-tetrakis (4-hydroxyphenyl)]-xylene.

Dyes Suitable dyes include oil dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 1
03, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-5
05 (all manufactured by Orient Chemical Industries, Ltd.), crystal violet (CI42555), methyl violet (CI42535), rhodamine B (CI45170)
B), malachite green (CI42000), methylene blue (CI52015) and the like.

Further, a spectral sensitizer as described below is added to sensitize the photosensitive composition of the present invention to a longer wavelength region than the deep ultraviolet where the photoacid generator used has no absorption. Sensitivity can be given to the i or g line. Suitable spectral sensitizers include, specifically, benzophenone,
p, p'-tetramethyldiaminobenzophenone, p,
p'-tetraethylethylaminobenzophenone, 2-
Chlorothioxanthone, anthrone, 9-ethoxyanthracene, anthracene, pyrene, perylene, phenothiazine, benzyl, acridine orange, benzoflavin, setoflavin-T, 9,10-diphenylanthracene, 9-fluorenone, acetophenone, phenanthrene, 2-nitrofluorene, 5-nitroacenaphthene, benzoquinone, 2-chloro-4-nitroaniline,
N-acetyl-p-nitroaniline, p-nitroaniline, N-acetyl-4-nitro-1-naphthylamine, picramide, anthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone 1,2-benzanthraquinone, 3-methyl-1,3-diaza-1,
9-benzanthrone, dibenzalacetone, 1,2-
Naphthoquinone, 3,3′-carbonyl-bis (5,7-
Dimethoxycarbonylcoumarin) and coronene, but are not limited thereto. Further, these spectral sensitizers can also be used as a light absorbing agent for far ultraviolet light of a light source. In this case, the light absorbing agent further reduces the light reflected from the substrate provided with the anti-reflection film, reliably removes the influence of multiple reflections in the resist film, and has the effect of eliminating standing waves.

Organic Basic Compound Preferred organic basic compounds that can be used in the present invention are compounds that are more basic than phenol. Among them, a nitrogen-containing basic compound is preferable. Preferred chemical environments include the structures of the following formulas (A) to (E).

[0186]

Embedded image

Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms having different chemical environments in one molecule, and particularly preferred is a ring structure containing a substituted or unsubstituted amino group and 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, 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 Or, unsubstituted aminomorpholine, substituted or unsubstituted aminoalkylmorpholine and the like can be mentioned. Preferred substituents are an amino group, an aminoalkyl group, an alkylamino group, an aminoaryl group, an arylamino group, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, an aryloxy group, a nitro group, a hydroxyl group, a cyano group It is.

As particularly preferred compounds, guanidine and
1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, imidazole, 2-methylimidazole, 4-methylimidazole, N-methylimidazole, 2-phenylimidazole, 4,5-diphenylimidazole, , 4,5-triphenylimidazole, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine,
-(Aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, -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-amino Ethyl) 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] -5-Nonene, 1,8-diazabicyclo [5.
4.0] -5-undecene and the like, but is not limited thereto.

These nitrogen-containing basic compounds are used alone or in combination of two or more. The ratio of the photoacid generator and the organic basic compound used in the composition is (photoacid generator) / (organic basic compound) (molar ratio) =
2.5 to 30.0. If the molar ratio is less than 2.5, the sensitivity becomes low and the resolving power decreases. If the molar ratio exceeds 30.0, the resist pattern becomes thinner over time until the heat treatment after exposure, and the resolving power also decreases. (Photoacid generator) / (organic basic compound) (molar ratio) is preferably from 3.0 to 25.0, more preferably from 5.0 to 20.0. Solvents The photosensitive composition of the present invention is dissolved in a solvent that dissolves each of the above components, and applied 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, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, ethyl pyruvate, methyl pyruvate , Pyruvate, N, N-dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc., and these solvents are used alone or in combination.

Surfactants Surfactants may be added to the above solvents. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether and the like Sorbitan such as polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate Fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopal Te - DOO, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, nonionic surfactants of polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan tristearate, Eftop EF301, E
F303, EF352 (manufactured by Shin-Akita Chemical Co., Ltd.), Megafac F171, F173 (Dainippon Ink Co., Ltd.)
), Florad FC430, FC431 (manufactured by Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, S
C104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.)
Fluorinated surfactants such as organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and acrylic or methacrylic acid (co) polymerized polyflow Nos. 7
5, No. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and the like. The amount of these surfactants is usually 2 parts by weight per 100 parts by weight of the solid content in the composition of the present invention.
It is at most 1 part by weight, preferably at most 1 part by weight. These surfactants may be added alone or in some combination.

In the production of precision integrated circuit elements, the pattern formation step on the resist film is performed by forming an anti-reflection film on a substrate (eg, a transparent substrate such as a silicon / silicon dioxide coating, a glass substrate, an ITO substrate, etc.) if necessary. Is applied by an appropriate application method such as a spinner or a coater, and baked to cure the composition for an antireflection film material to form an antireflection film. Then, apply a photoresist composition,
Next, by exposing, developing, rinsing and drying through a predetermined mask, a good resist-coated product can be obtained. Post-exposure heating (PEB: Post Exposur if necessary)
e Bake).

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

Of these developers, quaternary ammonium salts are preferred, and tetramethylammonium hydroxide and choline are more preferred.

[0195]

[Examples 1 to 11, Comparative Examples 1 and 2]

(1) Application of Resist A solution of a photoresist composition having the composition shown in Table 1 below (using propylene glycol monomethyl ether acetate as a solvent, 18% by weight of solid content) was prepared. After each sample solution is filtered through a 0.2 μm filter, it is applied on a silicon wafer using a spin coater,
The resist film was dried on a vacuum adsorption type hot plate at 120 ° C. for 90 seconds to obtain a resist film having a thickness of 0.74 μm.

(2) Preparation of resist pattern A 248 nm KrF excimer laser stepper [NSR-1505EX manufactured by Nikon (NA =
0.42)]. Immediately after the exposure, each was heated for 60 seconds on a vacuum adsorption type hot plate at 110 ° C., immediately immersed in a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 seconds, rinsed with water for 30 seconds, and dried. Thus, a resist pattern was obtained on the silicon wafer.

[0197]

[Table 1]

The materials or abbreviations used in Table 1 represent the following contents.

[0199]

Embedded image

[0200]

Embedded image

[0201]

Embedded image

[0202]

Embedded image

[0203]

Embedded image

[0204]

Embedded image

(3) Evaluation of Photoresist Pattern A resist pattern on the obtained silicon wafer was observed with a scanning electron microscope to evaluate a pattern profile. Specifically, the sidewall angle of the profile of the limit resolution pattern was evaluated as follows, and the evaluation results are shown in Table 2 below.

Sidewall Angle of Profile of Limit Resolution Pattern The side wall angle with respect to the silicon wafer in the limit resolution pattern (μm) at the exposure dose for reproducing a mask pattern of 0.40 μm was used. Here, the limit resolution pattern is
At this exposure amount, it represents the limit line width that can be resolved, that is, the minimum line width where adjacent lines do not fuse at the base as shown in FIG. The larger the side wall angle of the profile of the limit resolution pattern, the better the resolution and the rectangular pattern can be obtained.

[0207]

[Table 2]

[Explanation of Evaluation Results] According to the results shown in Table 2, Examples 1 to 11 of the present invention had sufficient sensitivity, a large side wall angle of the profile of the limit resolution pattern, and excellent resolution and pattern profile. . On the other hand, in comparison with those, in Comparative Examples 1 and 2, it can be seen that the side wall angle of the profile of the limit resolution pattern is small, and the resolution and the pattern profile are insufficient.

[0209]

According to the present invention, a short wavelength light source (in particular, KrF
Excimer laser), high sensitivity, high resolution,
It is possible to provide a positive photoresist composition having an excellent pattern profile, and among them, an improvement in resolution (limit resolution).

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a limit resolution pattern in a resist pattern.

Claims (4)

[Claims] (1) a compound having a group capable of decomposing with an acid represented by the following general formula (I), which decomposes by the action of an acid to increase the solubility in an alkali developer, (b) an actinic ray or A positive photoresist composition comprising a compound which decomposes upon irradiation with radiation to generate an acid, and (c) a compound which decomposes upon irradiation with actinic rays or radiation to generate a base. Embedded image In the formula, R ₁ represents a hydrogen atom or a methyl group. R ₂ represents a methyl group or an ethyl group, and R ₃ represents an alkyl group having 1 to 4 carbon atoms. 2. The resin according to claim 1, wherein the compound (a) is a resin in which a hydroxyl group in poly (p-hydroxystyrene) or a copolymer containing the same is substituted with a group represented by the general formula (I). The positive photoresist composition according to claim 1. 3. The positive resist composition according to claim 1, further comprising a compound in which a hydroxyl group of a phenolic compound having a molecular weight of 3000 or less is substituted with a group capable of decomposing under the action of an acid. 4. The positive resist composition according to claim 1, further comprising an organic basic compound.