JP2001100417A - Positive type photoresist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a positive type photoresist composition having high sensitivity and high resolving power of <=0.2 μm in the production of a semiconductor device, having a rectangular shape and less liable to cause a dimensional shift in pattern transfer to a lower layer in an oxygen plasma etching step when the composition is used as the upper layer resist of a two-layer resist system. SOLUTION: The positive type photoresist composition contains a polysiloxane containing at least a siloxane structural unit of formula I [where L is a single bond or arylene, A is an aromatic ring or an alicyclic structure which may have a substituent and (n) is an integer of 1-6] and a siloxane structural unit having a group which is decomposed by an acid and generates an alkali-soluble group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photoresist composition used for manufacturing semiconductor integrated circuit elements, masks for manufacturing integrated circuits, printed wiring boards, liquid crystal panels, and the like.

[0002]

2. Description of the Related Art As a pattern forming method for manufacturing electronic components such as a semiconductor device, a magnetic bubble memory, and an integrated circuit, a method utilizing a photoresist which is sensitive to ultraviolet light or visible light has been widely used. Have been. There are two types of photoresist: a negative type, in which the irradiated part is insoluble in the developer by light irradiation, and a positive type, in which the exposed part is solubilized.The negative type has higher sensitivity than the positive type and is necessary for wet etching. Until recently, photoresists occupied the mainstream because of their excellent adhesion to substrates and chemical resistance.

However, with the increase in density and integration of semiconductor devices and the like, the line width and spacing of patterns have become extremely small.
In addition, since dry etching has been adopted for etching the substrate, photoresists have been desired to have high resolution and high dry etching resistance,
At present, positive photoresists occupy the majority. In particular, among positive photoresists, sensitivity,
Because of its excellent resolution and dry etching resistance, for example, JC Strieta, Kodak Microelectronics Seminar Proceedings, p. 116 (1976) (JC Strieter, Kodak Micro)
electronics Seminar Proceedings, 116 (1976
) And the like, and an alkali-developing positive photoresist based on an alkali-soluble novolak resin is the mainstream of the current process.

However, in recent years, multifunctional electronic devices have been
As the sophistication increases, there is a strong demand for finer patterns to achieve higher densities and higher integration. That is, since the vertical dimension of the integrated circuit is not much reduced as compared with the horizontal dimension of the integrated circuit, the ratio of the height to the width of the resist pattern has to be increased. For this reason, it has become more difficult to suppress the dimensional change of the resist pattern on a wafer having a complicated step structure as the pattern becomes finer.

[0005] Further, in various exposure methods, a problem has arisen as the minimum size is reduced. For example, in light exposure, the interference effect of reflected light due to the step of the substrate has a great effect on dimensional accuracy, whereas in electron beam exposure, the fine resist is exposed due to the proximity effect caused by backscattering of electrons. It is no longer possible to increase the height to width ratio of the pattern.

[0006] It has been found that many of these problems are eliminated by using a multilayer resist system. For a description of multilayer resist systems, see Solid State Technology, 74 (1981) [Solid State Technolog
y, 74 (1981)], but many other studies on this system have been published. Generally, a multilayer resist method includes a three-layer resist method and a two-layer resist method. In the three-layer resist method, an organic flattening film is applied on a stepped substrate, an inorganic intermediate layer and a resist are stacked thereon, and the resist is patterned. Then, the inorganic intermediate layer is dry-etched using the resist as a mask. This is a method of patterning an organic planarization film by O ₂ RIE (reactive ion etching) using the inorganic intermediate layer as a mask. Basically, this method has been studied from an early stage because conventional techniques can be used, but the process is very complicated, or the organic film, the inorganic film, and the organic film have different three-layer physical properties. The problem is that cracks and pinholes are likely to occur in the intermediate layer due to the overlapping of the objects.

In contrast to the three-layer resist method, the two-layer resist method uses a resist having both properties of the resist and the inorganic intermediate layer in the three-layer resist method, that is, a resist having oxygen plasma resistance. In addition, the generation of cracks and pinholes is suppressed, and the process is simplified because the number of layers is reduced from three to two. However, in the three-layer resist method, a conventional resist can be used as the upper resist, whereas in the two-layer resist method, there is a problem that a new resist having oxygen plasma resistance has to be developed.

[0008] From the above background, it has excellent oxygen plasma resistance which can be used as an upper layer resist such as a two-layer resist method.
There has been a demand for the development of a high-sensitivity, high-resolution positive photoresist, in particular, an alkali developing type resist that can be used without changing the current process.

On the other hand, a polysiloxane having alkali solubility added to a conventional orthoquinonediazide photosensitive material,
Or a photosensitive composition combining a silicone polymer such as polysilmethylene, for example, JP-A-61-144639, JP-A-61-256347, JP-A-62-159141, and JP-A-6-159141.
2-191849, 62-220949, 62
-229136, 63-90534, 63-9
1654 and U.S. Pat. No. 4,722,881 and a photosensitive composition obtained by combining an effective amount of an onium salt with a polysiloxane / carbonate block copolymer described in JP-A-62-136638. Proposed.

However, any of these silicone polymers has a phenolic OH group or a silanol group (≡Si
-OH) is introduced to impart alkali solubility, and when alkali solubility is imparted by introduction of a phenolic OH group, the production becomes extremely difficult. There was a problem that the film was not good, or the film loss after development was large, and rectangular properties could not be obtained. Also, Japanese Patent No. 2736939 and Japanese Patent Application Laid-Open No. 9-274319
Discloses a photoresist containing a polysiloxane having in its molecule a group that can be decomposed by the action of an acid. However, these photoresists have a problem that the resolution is low, the shape is not rectangular, and the size shift is large when transferring the pattern to the lower layer in the next oxygen plasma process.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device having a high sensitivity and a high sensitivity of 0.2 μm.
An object of the present invention is to provide a positive photoresist composition having a high resolution of not more than m and providing a photoresist having a rectangular shape. Another object of the present invention is to provide a positive photoresist composition having a small dimensional shift during pattern transfer to a lower layer in an oxygen plasma etching step when used as an upper layer resist in a two-layer resist system. . Still another object of the present invention is to provide a polysiloxane capable of imparting the above excellent properties to a positive photoresist composition.

[0012]

According to the present invention, the above-mentioned object of the present invention is achieved by providing the following polysiloxane and positive photoresist composition.

(1) A polysiloxane containing at least a siloxane structural unit represented by the following general formula (I) and a siloxane structural unit having a group capable of decomposing with an acid to generate an alkali-soluble group. Positive photoresist composition.

[0014]

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In the formula (I), L represents a single bond or an arylene group. A represents an aromatic ring or an alicyclic structure, each of which may have a substituent. n represents an integer of 1 to 6.

(2) The structural unit represented by the general formula (I) is derived from a monomer component synthesized by reacting a silane compound having an amino group with an aromatic acid anhydride or an alicyclic acid anhydride. The positive photoresist composition according to (1) above,

(3) The polysiloxane contains a structural unit represented by the following general formula (II) as a siloxane structural unit having a group capable of decomposing with an acid to generate an alkali-soluble group. The positive photoresist composition according to 1).

[0018]

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In the formula (II), L 'is -A-OCO-, -A
-COO-, -A-NHCO-, -A-NHCOO-,
-A-NHCONH-, -A-CONH- and -AS
Represents at least one divalent linking group selected from-. A represents a single bond or an arylene group. X represents a divalent linking group. Z is

[0020]

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R represents a group which can be decomposed by an acid. Y represents a hydrogen atom, a linear, branched or cyclic alkyl, aryl or aralkyl group. l is an integer of 1 to 3, m is 1
And n represents an integer of 1 to 6.

(4) The above-mentioned (1), wherein the polysiloxane contains a structural unit represented by the following general formula (III) as a siloxane structural unit having a group capable of decomposing with an acid to generate an alkali-soluble group. The positive photoresist composition as described in (1).

[0023]

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In the formula (III), L ″ represents —B—OCO—,
B-COO-, -B-NHCO-, -B-NHCOO
-, -B-NHCONH-, -B-CONH- and -B
Represents at least one divalent linking group selected from -S-. B represents a single bond or an arylene group. X represents a divalent linking group. Q represents an acid-decomposable group. n represents an integer of 1 to 6.

(5) The polysiloxane has the general formula (II)
(1) wherein both the structural unit represented by the general formula (III) and the structural unit represented by the general formula (III) contain a siloxane unit having a group capable of decomposing with an acid to generate an alkali-soluble group. Positive photoresist composition.

(6) (a) An acid-decomposed polysiloxane as described in any of (1) to (5) above, and (b) a compound which decomposes upon exposure to light to generate an acid. Positive photoresist composition.

(7) Further, (c) a phenolic compound (c1) in which at least a part of the phenolic hydroxyl group contained in the molecule is protected by an acid-decomposable group, or at least a carboxyl group contained in the molecule. (6) The positive photoresist composition as described in (6) above, which partially contains an aromatic or aliphatic carboxylic acid compound protected by an acid-decomposable group.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the polysiloxane of the present invention will be described. The polysiloxane of the present invention comprises at least a siloxane unit of the above general formula (I) and a group capable of decomposing with an acid to generate an alkali-soluble group (hereinafter also simply referred to as an acid-decomposable group).
Is a copolymerized siloxane unit having the formula: The siloxane unit having an acid-decomposable group is represented by the general formula (I
The siloxane units represented by I) and / or (III) are preferred.

In the general formula (I), L represents a single bond or an arylene group. The arylene group is preferably an arylene group having 6 to 11 carbon atoms including a substituent. Specifically, the arylene group may have an ortho, meta, or paraphenylene group which may have a substituent, and may have a substituent. And a naphthylene group. Preferred are a paraphenylene group and a naphthylene group.

A represents an aromatic or alicyclic structure, preferably a benzene ring which may have a substituent, a naphthalene ring which may have a substituent or a cyclo which may have a substituent. Represents an olefin ring, more preferably a benzene ring, an alkyl-substituted benzene ring, a naphthalene ring, a cyclohexane ring, a cyclohexene ring, an alkyl-substituted cyclohexane ring, a norbornane ring, or a norbornene ring.

L 'in the general formula (II) is -A-OC
O-, -A-COO-, -A-NHCO-, -A-NH
COO-, -A-NHCONH-, -A-CONH-,
-A-OCONH-, -A-CONHCO- and -A-
S- (wherein A represents a single bond or an arylene group.) Represents at least one divalent linking group selected from Karakara group consisting, inter alia _{-OCO -, - C 6 H 4} -OCO-
Is particularly preferable, and -OCO- is particularly preferable. The arylene group is preferably an arylene group having 6 to 11 carbon atoms including a substituent. Specifically, the arylene group may have an ortho, meta, or paraphenylene group which may have a substituent, and may have a substituent. And a naphthylene group. Preferred are a paraphenylene group and a naphthylene group.

X in the general formulas (II) and (III) is
Represents a single bond or a divalent linking group. Specific examples of the divalent linking group include a linear alkylene group having 1 to 6 carbon atoms, a branched alkylene group having 1 to 6 carbon atoms, a cycloalkylene group having 6 to 10 carbon atoms, and a 6 to 6 carbon atoms. Examples include a linking group composed of one kind selected from 10 arylene groups and an aralkylene group having 7 to 11 carbon atoms, and a linking group in which two or more kinds are linked. X represents -O-, -CO-, -S between X and Z.
-, - SO ₂ -, and may contain one or more groups selected from -CH = CH-. Preferred examples of the alkylene group include methylene, ethylene, propylene, and butylene. Preferred examples of the cycloalkylene group include cyclohexylene. Preferable examples of the arylene group include a phenylene group and a naphthylene group. Preferable examples of the aralkylene group include a phenylenemethylene group.

Y in the general formula (II) represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. The alkyl group may be linear, branched, or cyclic. The alkyl group preferably has 1 to 10 carbon atoms, the aryl group preferably has 6 to 10 carbon atoms, and the aralkyl group preferably has 7 to 11 carbon atoms. Specific examples of Y include a hydrogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group, i-
-Pentyl, n-hexyl, cyclohexyl, phenyl, naphthyl, benzyl, phenethyl, naphthylmethyl and the like. Above all, hydrogen atom,
A methyl group is preferred.

In the general formulas (I) to (III), n is 1
-6, preferably 1-3. In the formula (II), 1 represents an integer of 1 to 3, preferably 1 to 2, and m represents an integer of 1 to 3, preferably 1 to 2.

The acid-decomposable group as a protective group for protecting the phenolic hydroxyl group of the alkali-soluble polysiloxane represented by the general formula (II) to form an acid-decomposable polysiloxane is -CR ¹ R ² (OR ³ ), T-butoxycarbonyl group, t-butoxycarbonylmethyl group, t-
-Butyl group, t-amyl group, 1-methylcyclohexyl group, trimethylsilyl group and t-butyldimethylsilyl group. R ¹ and R ² are the same or different and each represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ³ is a linear or branched alkyl group having 1 to 10 carbon atoms. Or it is a cyclic alkyl group. Further R ²
And R ³ may combine to form a ring structure, preferably a ring structure having 6 ring members. Specific examples of preferred acid-decomposable groups include a t-butoxycarbonyl group, a t-butyl group, a trimethylsilyl group, a t-butyldimethylsilyl group, and a group represented by the following formula.

[0036]

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R ^{4 in the} above formula is methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl or t-
-Represents a butyl group.

R in the general formula (II) is the acid-decomposable group described above, and two or more different acid-decomposable groups may be combined.

The acid-decomposable group serving as a protective group for protecting the carboxyl group of the alkali-soluble polysiloxane represented by the general formula (III) to form an acid-decomposable polysiloxane is -CR ⁵ R ⁶ (OR ⁷ ) A tetrahydropyranyl group, a methoxymethyl group, an ethoxymethyl group, t
-Butyl group, t-amyl group, 1-methylcyclohexyl group, trimethylsilyl group and t-butyldimethylsilyl group. R ⁵ and R ⁶ are the same or different and each represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ⁷ is a linear or branched alkyl group having 1 to 10 carbon atoms. Or it is a cyclic alkyl group. Further R ⁶
R ⁷ may combine to form a ring structure, preferably a ring structure having 6 ring members. Specific examples of preferred acid-decomposable groups include a t-butyl group, a trimethylsilyl group, a t-butyldimethylsilyl group, an ethoxymethyl group, and a group represented by the following formula.

[0040]

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R ^{8 in the} above formula is methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl or t-butyl.
-Represents a butyl group.

Q in the general formula (III) is the acid-decomposable group described above, and two or more different acid-decomposable groups may be combined.

The siloxane unit having a group capable of decomposing with an acid to generate an alkali-soluble group used in the present invention includes:
In addition to the siloxane units represented by the above general formulas (II) and (III), siloxane units represented by the following (IV) and (V) are exemplified.

[0044]

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Here, Q is the same as the above Q, and p is 1
And an integer q is an integer of 1-3.

The acid-decomposable polysiloxane of the present invention has the following general formula (V) for controlling the solubility of a solvent and the solubility of an alkali.
The structural units of I) and / or (VII) may be co-condensed.

[0047]

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Here, X, X ¹ and X ² each represent a group having neither alkali solubility nor acid decomposability. Specifically, it may have a linear group having 1 to 10 carbon atoms which may have a substituent, may have a branched group having 3 to 10 carbon atoms which may have a substituent, or may have a substituent. A cyclic alkyl group having 6 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms which may have a substituent; or an aralkyl group having 7 to 11 carbon atoms which may have a substituent. . Preferred examples of these groups include methyl, ethyl, n-propyl, i-propyl,
n-butyl, i-butyl, t-butyl, n-pentyl,
Examples thereof include n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, cyclohexyl, phenyl, naphthyl, benzyl and naphthylmethyl.
The substituents of these groups include a halogen atom,
To 6 alkoxy groups, phenoxy groups, hydroxyl groups and the like. X ¹ and X ² may be the same or different.

The polysiloxane of the present invention is obtained by mixing at least a trialkoxysilane having a structure represented by the general formula (I) and a trialkoxysilane having a group capable of decomposing with an acid separately synthesized to generate an alkali-soluble group. And optionally adding a monosubstituted trialkoxysilane or a disubstituted dialkoxysilane to give a structural unit represented by the general formula (VI) and / or (VII), and then adding water and an acid, or water and a base catalyst. It can be obtained by condensation polymerization in the presence. The trialkoxysilane that gives the structural unit represented by the general formula (I) can be obtained from a monosubstituted trialkoxysilane having an amino group at a terminal and a cyclic acid anhydride.

Specifically, cyclohexanedicarboxylic anhydride, methylcyclohexyldicarboxylic anhydride, tetrahydrophthalic anhydride, norbornenedicarboxylic anhydride, norbornanedicarboxylic anhydride, cantharidin, methylnorbornenedicarboxylic anhydride, phthalic acid Anhydride, methylphthalic anhydride, dichlorophthalic anhydride, tetrachlorophthalic anhydride, hydroxyphthalic anhydride, nitrophthalic anhydride, naphthalenedicarboxylic acid anhydride, etc. It can be obtained by reacting a monosubstituted trialkoxysilane having a group (for example, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminophenyltrimethoxysilane).

On the other hand, as a trialkoxysilane compound having a group capable of decomposing with an acid to generate an alkali-soluble group, for example, when L ′ is —OCO— in the above general formula (II), (chloroalkyl) trialkoxy Silane and
After reacting a carboxylic acid compound having a phenol structure at the terminal thereof in the presence of a base catalyst (at this time, a salt such as potassium iodide or tetramethylammonium iodide may be added to accelerate the reaction), It is obtained by protecting a hydroxyl group with an acid-decomposable group. In the general formula (III), L ″ is, for example, —B—OCO—
Is a single bond, after reacting a trialkoxysilane having an amino group at the terminal with a cyclic acid anhydride at room temperature or lower, and then protecting the remaining carboxyl group with an acid-decomposable group.

The polysiloxane of the present invention may alternatively be
After the co-condensation polymerization of the alkoxysilane, a carboxylic acid having a phenol structure at the terminal is similarly reacted to obtain an alkali-soluble polysiloxane, and then an alkali-soluble polysiloxane and a vinyl ether compound corresponding to the acid-decomposable group. , Or a base-catalyzed reaction with di-t-butyl dicarbonate, trimethylsilyl chloride, or t-butyldimethylsilyl chloride.

L 'is -COO-, -NHCO-, -NH
COO-, -NHCONH-, -CONH- or -S-
Can be obtained in the same manner by using a trialkoxysilane having a carboxyl group, an amino group or a mercapto group at each terminal.

In the present invention, the content of the structural unit of the formula (I) and the structural unit of the formula (II) and / or the formula (III) is as follows:
The range of 30/70 to 80/20 (molar ratio) is preferable,
More preferably, it is in the range of 40/60 to 60/40 (molar ratio).

Specific examples of the structural units of the polysiloxane of the present invention, that is, the alkali-soluble polysiloxane and the acid-decomposable polysiloxane are shown below, but the present invention is not limited to these.

[0056]

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[0057]

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[0058]

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[0059]

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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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[0073]

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[0074]

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[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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The weight average molecular weight of the polysiloxane of the present invention is from 500 to 10,000 as a polystyrene equivalent value measured by gel permeation chromatography.
0 is preferable, 700 to 50,000 is more preferable, and 800 to 20,000 is particularly preferable.

Next, the positive photoresist composition of the present invention will be described. The positive photoresist composition of the present invention contains (a) the above polysiloxane, and (b) a compound (photoacid generator) which decomposes upon exposure to generate an acid.

Further, (c) a phenolic compound in which at least a part of the phenolic hydroxyl group contained in the (c1) molecule is protected by an acid-decomposable group, or (c2) at least one of the carboxyl groups contained in the molecule. Part is an aromatic or aliphatic carboxylic acid compound protected by an acid-decomposable group,
May be contained.

As the acid-decomposable polysiloxane, use of a polysiloxane having a structural unit represented by the general formula (III) is preferable in view of solvent solubility, sensitivity, resolution, and rectangularity of the pattern. Further, the composition may contain an alkali-soluble polysiloxane from which all the acid-decomposable groups of the acid-decomposable polymer of the present invention are removed, in an amount of 50% by weight or less in the present composition.

The photoacid generator (b) used in the present invention comprises:
A compound that generates an acid upon irradiation with actinic rays or radiation. Examples of the compound used in the present invention, which decomposes upon irradiation with actinic rays or radiation to generate an acid, include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, and a photodiscoloration agent. Agents or known light used in micro resists (400 to 200 nm ultraviolet light,
Far ultraviolet rays, particularly preferably g-line, h-line, i-line, KrF
Excimer laser light), ArF excimer laser light, an electron beam, an X-ray, a compound generating an acid by a molecular beam or an ion beam, and a mixture thereof can be appropriately selected and used.

Further, examples of the compound capable of generating an acid upon irradiation with actinic rays or radiation used in the present invention include, for example, SI Schlesinger, Photogr. Sci. Eng.,
18, 387 (1974), TS Bal et al, Polymer, 21, 423
(1980) diazonium salts described in U.S. Pat.No.4,069,05
No. 5, 4,069,056, 27,992, ammonium salts described in JP-A-3-140140, etc., DC Necker et al, Macrom
olecules, 17, 2468 (1984), CSWen et al, Teh, Pro
c. Conf. Rad. Curing ASIA, p.478 Tokyo, Oct (198
8), U.S. Pat.Nos. 4,069,055 and 4,069,056, phosphonium salts described in JVCrivello et al, Macromorecul
es, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 28,
p.31 (1988), European Patent Nos. 104,143 and 339,049,
410,201, JP-A-2-150848, iodonium salts described in JP-A-2-29514, etc., JV Crivelloet al, Polymer
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Sci., Polymer Chem. Ed., 22,1789 (1984), JV Cri
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JV Crivello et al, J. Polymer. Sci., Polymer C
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No. 61,811, No. 410,201, No. 339,049, No. 233,567,
No. 297,443, No. 297,442, U.S. Pat.No. 3,902,114,
4,933,377, 4,760,013, 4,734,444, 2,8
No. 33,827, Dokoku Patent No. 2,904,626, No. 3,604,580,
3,604,581, JP-A-7-28237, sulfonium salts described in JP-A-8-27102, etc., JV Crivello et al, Macromorec
ules, 10 (6), 1307 (1977), JV Crivello et al, J.
Selenonium salts described in Polymer.Sci., Polymer Chem.Ed., 17, 1047 (1979), CS Wen et al, Teh, Pro
c. Conf. Rad. Curing ASIA, p.478 Tokyo, Oct (1988)
Onium salts such as arsonium salts described in U.S. Pat.
3,905,815, JP-B-46-4605, JP-A-48-36281, JP-A-55-32070, JP-A-60-239736, JP-A-61-169835
No., JP-A-61-169837, JP-A-62-58241, JP-A-62-58241
212401, JP-A-63-70243, organic halogen compounds described in JP-A-63-298339, etc., K. Meier et al, J. Rad.
Curing, 13 (4), 26 (1986), TP Gill et al, Inorg.
Chem., 19, 3007 (1980), D. Astruc, Acc.
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21, 2001 (1988), European Patent Nos. 0290,750 and 046,083,
No. 156,535, No. 271,851, No. 0,388,343, U.S. Pat.No. 3,901,710, No. 4,181,531, JP-A-60-198538,
A photoacid generator having an O-nitrobenzyl-type protecting group described in JP-A-53-133022 and the like, M. TUNOOKA et al, Polymer P
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No. 5, 044,115, No. 618,564, No. 0101,122, U.S. Pat.Nos. 4,371,605, 4,431,774, JP-A-64-1814
No. 3, JP-A-2-245756, JP-A-3-140109, etc., compounds that generate sulfonic acid by photolysis, such as iminosulfonate, JP-A-61-166544, JP-A-2 -
Disulfone compound described in 71270, etc., JP-A-3-103854
And diazoketosulfone and diazodisulfone compounds described in JP-A Nos. 3-103856 and 4-210960.

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, ME Woodhouse et al, J. Am. Che.
m. Soc., 104, 5586 (1982), SP Pappas et al, J. I.
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da et al, Makromol.Chem., 152, 153, 163 (1972);
V. Crivello et al, J. Polymer Sci., Polymer Chem.
Ed., 17, 3845 (1979), U.S. Patent No. 3,849,137, Dokoku Patent No. 3,914,407, JP-A-63-26653, JP-A-55-164824.
No., JP-A-62-69263, JP-A-63-146038, JP-A-63-1
Compounds described in JP-A-63452, JP-A-62-153853, JP-A-63-146029 and the like 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 3,779,778, European Patent 1
Compounds that generate an acid by light described in No. 26,712 and the like can also be used.

Among the compounds capable of decomposing upon irradiation with actinic rays or radiation to generate an acid, those 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 (PAG)
An S-triazine derivative represented by 2).

[0089]

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

[0091]

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[0092]

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[0093]

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

[0095]

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Here, the formulas Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. 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, 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, 1 to 8 carbon atoms
And substituted derivatives thereof. Preferred substituents include an aryl group, an alkoxy group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms, a nitro group,
A carboxyl group, a hydroxy group and a halogen atom, and an alkyl group is an alkoxy group having 1 to 8 carbon atoms, a carboxyl group and an alkoxycarbonyl group.

[0098] Z ^- represents a counter anion, for example BF ₄ ^{-,
_{AsF 6 -, PF 6 -,}} SbF 6 -, SiF 6 2-, ClO 4 -,
CF ₃ SO ₃ ^-, etc. perfluoroalkane sulfonate anion, pentafluorobenzenesulfonic acid anion, condensed polynuclear aromatic sulfonic acid anion such as naphthalene-1-sulfonic acid anion, anthraquinone sulfonic acid anion, a sulfonic acid group-containing dyes Examples include, but are not limited to:

Further, 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 the following compounds, but are not limited thereto.

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[0115]

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The above onium salts represented by the general formulas (PAG3) and (PAG4) are known, 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, (19
64), H.M.Leicester, J. Am. Chem. Soc., 51, 3587 (1
929), JV Crivello et al, J. Polym. Chem. Ed., 1
8, 2677 (1980); U.S. Pat.Nos. 2,807,648 and 4,247,4
No. 73, JP-A-53-101,331 and the like.

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

[0118]

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In the formula, Ar^Three, Ar^FourAre each independently substituted
Or an unsubstituted aryl group. R ²⁰⁶Is replaced or
It represents 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.

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[0121]

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[0122]

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[0123]

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[0124]

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In the present invention, the photoacid generator (b) is preferably an onium salt, disulfone, 4-position DNQ (diazonaphthoquinone) sulfonic acid ester, or a triazine compound.

The amount of the photoacid generator (b) to be added is usually in the range of 0.001 to 40% by weight based on the total weight of the positive photoresist composition of the present invention (excluding the coating solvent). It is preferably used in the range of 0.01 to 20% by weight, more preferably 0.1 to 5% by weight. If the amount of the compound that decomposes upon irradiation with actinic rays or radiation to generate an acid is less than 0.001% by weight, the sensitivity becomes low. If the amount is more than 40% by weight, the light absorption of the resist becomes high. This is not preferable because the profile is deteriorated and the process (especially baking) margin is narrowed.

(C) The phenolic compound in which at least a part of the phenolic hydroxyl group contained in the molecule (c1) is protected by an acid-decomposable group, or (c)
2) As an aromatic or aliphatic carboxylic acid compound in which at least a part of the carboxyl group contained in the molecule is protected by an acid-decomposable group, for example, a compound having a molecular weight of 186 to 1500 containing 2 to 7 aromatic rings Aromatic compound or GP
The weight average molecular weight measured by the method C is 2000 to 2000
Compounds in which 20 to 100% of the hydroxyl groups of the phenolic compound selected from the hydroxystyrene copolymer in the range of 0 are protected by an acid-decomposable group can be exemplified. Here, the acid-decomposable group is the same as the acid-decomposable group as a protective group in which the phenolic hydroxyl group of the alkali-soluble polysiloxane represented by the general formula (II) is protected to form an acid-decomposable polysiloxane. The details have already been described.

The addition amount of the component (c) is preferably within the following range. (A) The positive photoresist composition of the present invention comprises (a)
When an acid-decomposable polysiloxane is contained as the polysiloxane, the component (c) is preferably 1 to 40% by weight, more preferably 2 to 30% by weight, based on the polysiloxane.
%, Particularly preferably 5 to 20% by weight. (B) The positive photoresist composition of the present invention comprises (a)
When an alkali-soluble polysiloxane and an acid-decomposable polysiloxane are contained as the polysiloxane, the component (c) is preferably 1 to 30% by weight, more preferably 2 to 25% by weight based on the polysiloxane, Particularly preferably, it is 5 to 15% by weight.

As the component (c), the following compounds are specifically mentioned.

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

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A group selected from the following. However, at least two or three depending on the structure are groups other than hydrogen atoms, and each substituent R may not be the same group. )

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The composition of the present invention may contain an organic basic compound. This is preferable because the storage stability is improved and the line width change due to PED is reduced. 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).

[0157]

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Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are the same or different and are a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aminoalkyl group having 1 to 6 carbon atoms, a hydroxyalkyl having 1 to 6 carbon atoms. Group or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, wherein R ²⁵¹ and R ²⁵² may be bonded to each other to form a ring.

[0159]

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In the above formula (E), R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ are the same or different and represent an alkyl group having 1 to 6 carbon atoms.

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 are substituted or unsubstituted guanidine,
Substituted or unsubstituted aminopyridine, substituted or unsubstituted aminoalkylpyridine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted indazole, substituted or unsubstituted pyrazole, substituted or unsubstituted pyrazine, substituted or unsubstituted Pyrimidine, substituted or unsubstituted purine, substituted or unsubstituted imidazoline, substituted or unsubstituted pyrazoline, substituted or unsubstituted piperazine, substituted or unsubstituted aminomorpholine, substituted or unsubstituted aminoalkylmorpholine, etc. Is mentioned. Preferred substituents are an 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 It is.

As particularly preferred compounds, guanidine and
1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine , 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-
6-methylpyridine, 3-aminoethylpyridine, 4-
Aminoethylpyridine, 3-aminopyrrolidine, piperazine, N- (2-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-
Examples include (2-aminoethyl) morpholin and the like, but are not limited thereto.

These nitrogen-containing basic compounds are used alone or in combination of two or more. The amount of the nitrogen-containing basic compound to be used is the photosensitive resin composition (excluding the solvent) 1
The amount is usually 0.001 to 10 parts by weight, preferably 0.01 to 5 parts by weight, based on 00 parts by weight. If the amount is less than 0.001 part by weight, the above effects cannot be obtained. On the other hand, if it exceeds 10 parts by weight, the sensitivity tends to decrease and the developability of the unexposed part tends to deteriorate.

The positive photoresist composition of the present invention may further contain, if necessary, a phenolic OH group which promotes solubility in a surfactant, a dye, a pigment, a plasticizer, a photosensitizer and a developer. Compounds having two or more compounds can be contained.

Suitable surfactants include, specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether,
Polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene alkyl allyl ethers such as polyoxyethylene octyl phenol ether and polyoxyethylene nonyl phenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate ,
Sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan fatty acid esters such as sorbitan tristearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; F-Top EF301, EF303;
EF352 (manufactured by Shin-Akita Chemical Co., Ltd.), MegaFac F1
71, F173 (manufactured by Dainippon Ink Co., Ltd.), Florado FC430, FC431 (manufactured by Sumitomo 3M Limited),
Asahi Guard AG710, Surflon S-382, SC
101, SC102, SC103, SC104, SC1
05, SC106 (manufactured by Asahi Glass Co., Ltd.), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), acrylic acid or methacrylic acid (co) polymerized polyflow No. 75, no. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and the like.

[0166] These surfactants may be added alone or in some combination. A preferable addition amount is 100 parts of the composition (excluding the solvent).
0.0005 to 0.01 parts by weight with respect to parts by weight. Suitable dyes include oily dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green B
G, oil blue BOS, oil blue # 603, oil black BY, oil black BS, oil black T-505 (all manufactured by Orient Chemical Co., Ltd.), crystal violet (CI42555), methyl violet (CI42535), rhodamine B (CI45)
170B), malachite green (CI42000),
Methylene blue (CI52015) and the like can be mentioned.

Further, the following spectral sensitizers are added to sensitize the photoacid generator to be used in a longer wavelength region than in the deep ultraviolet where the photoacid generator used has no absorption, thereby obtaining the chemically amplified positive resist of the present invention. Can be made sensitive to i or g rays. Examples of suitable spectral sensitizers include benzophenone, p, p'-tetramethyldiaminobenzophenone, p, p'-tetraethylethylaminobenzophenone, 2-chlorothioxanthone, anthrone, 9-ethoxyanthracene, anthracene and pyrene. , Perylene,
Phenothiazine, benzyl, acridine orange, benzoflavin, cetoflavin-T, 9,10-diphenylanthracene, 9-fluorenone, acetophenone, phenanthrene, 2-nitrofluorene, 5-nitroacenaphthene, benzoquinone, 2-chloro-4-nitro Aniline, N-acetyl-p-nitroaniline, p-nitroaniline, N-acetyl-4-nitro-1-naphthylamine, viclamide, anthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1,
2-benzanthraquinone, 3-methyl-1,3-diaza-1,9-benzanthrone, dibenzalacetone,
Examples include, but are not limited to, 1,2-naphthoquinone, 3,3'-carbonyl-bis (5,7-dimethoxycarbonylcoumarin) and coronene.

Examples of the compound having two or more phenolic hydroxyl groups that promote solubility in a developer include a polyhydroxy compound. Preferably, the polyhydroxy compound includes phenols, resorcin, phloroglucin, phloroglucside, 2,3 , 4-trihydroxybenzophenone, 2,3,4,4′-tetrahydroxybenzophenone, α, α ′, α ″ -tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene,
Tris (4-hydroxyphenyl) methane, Tris (4
-Hydroxyphenyl) ethane, 1,1'-bis (4-
(Hydroxyphenyl) cyclohexane.

The positive photoresist composition of the present invention comprises
The above components are dissolved in a solvent that dissolves the components, and coated on a support. Examples of the solvent that can be used include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, and ethylene glycol. Monomethyl ether,
Ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate , Methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, tetrahydrofuran, and the like, and these solvents are used alone or in combination.

The positive photoresist composition of the present invention is applied onto a substrate (eg, silicon / silicon dioxide coating) such as used in the production of precision integrated circuit devices by a suitable application method such as a spinner or a coater. By exposing through a predetermined mask, baking and developing, a good resist pattern can be obtained.

Examples of the developing solution for the positive photoresist composition of the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium phosphate, sodium metasilicate, and aqueous ammonia. , Ethylamine, primary amines such as n-propylamine, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, and alcoholamines such as dimethylethanolamine and triethanolamine. , Amides such as formamide and acetamide, tetramethylammonium hydroxide, trimethyl (2-hydroxyethyl) ammonium hydroxide, tetraethylammonium hydroxide, tributylmethylammonium hydroxide, Ethanol ammonium hydroxide, methyl triethanol ammonium hydroxide,
Quaternary ammonium salts such as benzylmethyldiethanolammonium hydroxide, benzyldimethylethanolammonium hydroxide, benzyltriethanolammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide; cyclic amines such as pyrrole and piperidine; There are aqueous solutions of alkalis.

The positive photoresist composition of the present invention comprises
Basically, it is composed of the components (a) and (b) described above and the component (c). In order to further improve the film properties and heat resistance, an alkali-soluble resin other than the component (a) is added. May be. As such an alkali-soluble resin, preferably, a phenolic hydroxyl group, a carboxylic acid group,
It is a polymer having an acidic hydrogen atom having a pKa of 11 or less, such as a sulfonic acid group, an imide group, a sulfonamide group, an N-sulfonylamido group, an N-sulfonylurethane group and an active methylene group.

Suitable alkali-soluble polymers include:
Novolak phenol resins, specifically, phenol formaldehyde resins, o-cresol-formaldehyde resins, m-cresol-formaldehyde resins, p-cresol-formaldehyde resins, xylenol-formaldehyde resins, or co-condensates thereof. Further, as described in JP-A-50-125806, t
A condensate of phenol or cresol substituted with an alkyl group having 3 to 8 carbon atoms, such as -butylphenol formaldehyde resin, and formaldehyde may be used in combination. Also, a polymer having a phenolic hydroxy group-containing monomer such as N- (4-hydroxyphenyl) methacrylamide as a copolymer component, p-hydroxystyrene, o-hydroxystyrene, m-isopropenylphenol, p-isopropenylphenol Or a homo- or copolymerized polymer, or a polymer in which these polymers are partially etherified or partially esterified.

When the resist of the positive photoresist composition of the present invention is used as the upper resist of a two-layer resist, the lower organic polymer film is etched by oxygen plasma using the upper resist pattern as a protective mask. The upper resist has sufficient resistance to oxygen plasma. Although the oxygen plasma resistance of the positive photoresist composition of the present invention depends on the silicon content of the upper resist, the etching apparatus, and the etching conditions, the etching selectivity (the etching rate ratio between the lower resist and the upper resist) is 10%. It can be taken as a sufficiently large value of ~ 100.

In the pattern forming method using the positive photoresist composition of the present invention, first, an organic polymer film is formed on a substrate to be processed. The organic polymer film may be various known photoresists, and examples thereof include FH series and FHi series manufactured by Fujifilm Olin Co., or OiR series manufactured by Olin Co., and PFI series manufactured by Sumitomo Chemical Co., Ltd. The formation of the organic polymer film is performed by dissolving these in an appropriate solvent and applying the resulting solution by a spin coating method, a spraying method or the like. Next, a film of the positive photoresist composition of the present invention is formed on the first layer of the organic polymer film. This is performed by dissolving the resist material in an appropriate solvent in the same manner as in the first layer, and applying the resulting solution by spin coating, spraying, or the like. The obtained two-layer resist is then subjected to a pattern forming step. As a first step, a pattern forming process is first performed on the second layer, that is, the film of the upper photoresist composition. Perform mask alignment as necessary, and irradiate high-energy radiation through this mask to make the irradiated portion of the photoresist composition soluble in an alkaline aqueous solution,
The pattern is formed by developing with an alkaline aqueous solution.

Next, as a second step, the organic polymer film is etched. This operation is performed by oxygen plasma etching using the film pattern of the resist composition as a mask to form a fine pattern having a high aspect ratio. I do. The etching of the organic polymer film by the oxygen plasma etching is exactly the same technique as the plasma ashing used when the resist film is peeled off after the etching of the substrate is completed by the conventional photoetching operation. This operation can be performed by, for example, a cylindrical plasma etching apparatus or a parallel flat slope plasma etching apparatus using oxygen as a reactive gas, that is, an etching gas. Further, the substrate is processed using this resist pattern as a mask. As a processing method, a dry etching method such as sputter etching, gas plasma etching, or ion beam etching can be used.

The etching treatment by the two-layer film resist method including the resist film of the present invention is completed by the operation of removing the resist film. The removal of the resist layer can be carried out simply by dissolving the organic polymer material of the first layer. Since this organic polymer material is an arbitrary photoresist and has not been altered (hardened or the like) at all in the photoetching operation, an organic solvent of each known photoresist itself can be used. Or,
By a process such as plasma etching, separation can be performed without using a solvent.

[0178]

Hereinafter, Synthesis Examples, Examples and Comparative Examples will be shown.
The present invention is not limited to the following examples.

Synthesis Example 1 {Synthesis of Polysiloxane (C-57 ') } 22.1 g of 3-aminopropyltrimethoxysilane was
After adding to 200 ml of dried N, N-dimethylacetamide, 16.4 g of norbornene dicarboxylic anhydride was added.
Was added. The reaction was carried out at 140 ° C. for 15 hours in a dry nitrogen atmosphere, and the reaction solution was returned to room temperature (this is called a reaction solution intermediate A solution). Separately, 20 g of 3-chloropropyltrimethoxysilane was added to 200 ml of dried N, N-dimethylacetamide and then 28.7 of diphenolic acid.
g, potassium iodide 3.0 g and DBU (1,8-diazabicyclo [5.4.0] -7-undecene) 16.0.
g was added. The reaction was carried out at 70 to 90 ° C. for 5 hours in a dry nitrogen atmosphere (this is called a reaction intermediate B liquid).

After returning the solution B to room temperature, the solution A was added, and 2 g of dimethylaminopyridine and 15 g of distilled water were added. The mixture was reacted at 50 ° C. for 3 hours and then at 130 to 140 ° C. for 12 hours. After neutralizing the reaction solution with diluted hydrochloric acid, distilled water 3
The mixture was charged into L under stirring to obtain a white powdery polymer.
After dissolving this in 200 ml of acetone, the oligomer component of the polymer was separated and removed by adding distilled water under stirring, and the lower layer was reprecipitated in 2 L of distilled water to obtain a white polymer (C-57 ′). Obtained. When the average molecular weight of this polymer was measured by GPC (polystyrene standard), it was 8300 in weight average molecular weight, and the content of components having a molecular weight of 1,000 or less was 8% in GPC area ratio.

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[0182] Synthesis Example 2 {polysiloxane synthesis of (C-57)} vacuum dried above polysiloxane (C-57 ') 20g
Was dissolved in 100 ml of THF, 4.3 g of ethyl vinyl ether and 20 mg of p-toluenesulfonic acid monohydrate were added, and the mixture was reacted at room temperature for 10 hours. After the reaction was quenched by adding triethylamine, it was added to 2 L of distilled water to precipitate a polymer, followed by vacuum drying at room temperature to obtain 19 g of the objective polysiloxane (C-2) .

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Synthesis Example 3 Synthesis of Polysiloxane (C-60) The polysiloxane (C-57 ′) obtained in Synthesis Example 1 was vacuum-dried, and 20 g thereof was dissolved in 100 ml of THF. After adding 2.8 g of di-t-butyl dicarbonate, 1.3 g of triethylamine was added dropwise over 1 hour, and the mixture was further reacted at room temperature for 10 hours. Put into 2 L of distilled water with stirring,
After precipitating the polymer, the polymer was dried under reduced pressure at room temperature to obtain 18.2 g of a target polysiloxane (C-60).

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Example 1 1.6 g of polysiloxane (C-57) as acid-decomposable polysiloxane (component (a)) and triphenylsulfonium-2,4,6-trioxane as acid-generating compound (component (b)) 0.12 g of isopropylphenylsulfonate, 0.012 g of triphenylimidazole and a compound example (6
0) (where _{R = -CH 2 COOC (CH 3} ) 3) 0.4
g was used as a component c and dissolved in 19.2 g of propylene glycol monomethyl ether acetate, followed by precision filtration with a 0.1 μm membrane filter.

A silicon wafer was coated with FHi-028D resist (i-line resist, manufactured by Fujifilm Ohlin Co.) using a coater CDS-650 manufactured by Canon Inc.
Baking was performed at 0 ° C. for 90 seconds to obtain a uniform film having a thickness of 0.83 μm. When this was further heated at 200 ° C. for 3 minutes, the film thickness became 0.71 μm. The silicon-containing resist prepared above was applied thereonto and baked at 90 ° C. for 90 seconds to form a resist.
It was applied with a film thickness of 20 μm.

The wafer obtained in this way is manufactured by Canon K
rF excimer laser stepper FPA-3000EX
3 was loaded with a resolving power mask and exposed while changing the exposure amount and focus. Then, in a clean room at 120 ° C, 9
After heating for 0 second, the film was developed with a tetramethylammonium hydroxide developer (2.38%) for 60 seconds, rinsed with distilled water and dried to obtain a pattern. Observation with a scanning electron microscope revealed that the sensitivity was 0.16 μm at 30 mJ / cm ² .
m lines / spaces were resolved. The rectangularity of the cross section was evaluated as A.

The rectangularity of the cross section was compared by a three-step evaluation as follows. That is, the angle between the substrate and the side wall of the resist pattern was measured, and the angle between 80 ° and 90 ° was A
Evaluated, those with 70 ° or more and less than 80 ° were evaluated as B, and those with less than 70 ° were evaluated as C. Further, the wafer was subjected to an etching treatment for 15 minutes under the conditions of a pressure of 20 mTorr and an applied power of 100 mW / cm ² using an etching gas of oxygen and a parallel plate type reactive ion etching apparatus manufactured by ULVAC. The results were observed with a scanning electron microscope. The dimensional shift of the 0.16 μm pattern is 0.009
μm.

Examples 2 to 16 The acid-decomposable siloxane in Example 1 (component (a)),
Exactly the same as Example 1 except that the polysiloxane (component (a)), component (b) and component (c) shown in Table-A were used instead of component (b) and component (c), respectively. In this manner, a positive photoresist was prepared, and exposed, developed and etched in the same manner as in Example 1. The obtained resist performance is summarized in Table-B.

Example 17 As an acid-decomposable siloxane (component (a)), 1.9 g of polysiloxane (C-60) and an acid-generating compound (component (b))
0.12 g of triphenylsulfonium-2,4,6-triisopropylphenylsulfonate, 0.012 g of triphenylimidazole and compound example (60)
(Where _{R = -CH 2 COOC (CH 3} ) 3) 0.143
A positive photoresist was prepared in exactly the same manner as in Example 1, except that g was used as the component (c). Further, coating, exposure, development and etching were performed in the same manner as in Example 1, and the results were observed with a scanning electron microscope. Table C shows the prepared resists, and Table D shows the evaluation results.

Examples 18 to 32 The siloxane, component (b) and component (c) shown in Table C were used in place of the acid-decomposable siloxane, component (b) and component (c) in Example 17, respectively. Except for Example 1
A positive photoresist was prepared exactly in the same manner as in Example 7, and exposed, developed and etched in the same manner as in Example 17. Table D summarizes the obtained resist properties.

Comparative Example 1 The same procedure as in Example 1 was repeated except that the following polysiloxane (D-1) was used in place of the polysiloxane of Example 1, and coating, exposure, development and etching were performed. Observed with a scanning electron microscope in the same manner as described above. The results are shown in Table-E.

Comparative Example 2 Coating, exposure, development and etching were carried out in exactly the same manner as in Example 1 except that the following polysiloxane (D-2) was used in place of the polysiloxane of Example 1. Observed with a scanning electron microscope in the same manner as described above. The results are shown in Table-E.

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[0196]

[Table 1]

[0197]

[Table 2]

[0198]

[Table 3]

[0199]

[Table 4]

[0200]

[Table 5]

[0201]

[Table 6]

[0202]

[Table 7]

[0203]

[Table 8]

The following are clear from the results shown in Tables A to E. The positive photoresist composition using the polysiloxane of the present invention provides a resist having high resolution, good rectangularity, and a small dimensional shift after etching, and has a good balance of these properties. On the other hand, in the case of Comparative Examples 1 and 2 in which the polysiloxane of the present invention was not used, the balance of the above characteristics was poor. Also,

[0205]

According to the positive photoresist composition of the present invention using the polysiloxane of the present invention, a rectangular resist having high sensitivity and high resolution can be obtained. Furthermore, when used as an upper layer resist of a two-layer resist system, a fine pattern with a small aspect shift and a high aspect ratio can be formed when transferring a pattern to a lower layer using an oxygen-based plasma etching process.

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2H025 AA00 AA01 AA02 AA03 AB08 AB15 AB16 AB20 AC01 AC04 AC08 AD03 BE00 BE10 BG00 CB17 CB33 CB41 CB43 CB45 CB52 CC20 FA17

Claims (7)

[Claims] 1. A polysiloxane containing at least a siloxane structural unit represented by the following general formula (I) and a siloxane structural unit having a group capable of decomposing with an acid to generate an alkali-soluble group. Positive photoresist composition. Embedded image In the formula (I), L represents a single bond or an arylene group. A represents an aromatic ring or an alicyclic structure, each of which may have a substituent. n represents an integer of 1 to 6. 2. The structural unit represented by the general formula (I) is derived from a monomer component synthesized by reacting a silane compound having an amino group with an aromatic acid anhydride or an alicyclic acid anhydride. The positive photoresist composition according to claim 1, which is: 3. The polysiloxane comprises a structural unit represented by the following general formula (II) as a siloxane structural unit having a group capable of decomposing with an acid to generate an alkali-soluble group. The positive photoresist composition as described in the above. Embedded image In the formula (II), L 'is -A-OCO-, -A-COO-,
-A-NHCO-, -A-NHCOO-, -A-NHC
Represents at least one divalent linking group selected from ONH-, -A-CONH- and -AS-. A represents a single bond or an arylene group. X represents a divalent linking group. Z
Is R represents a group that can be decomposed by an acid. Y represents a hydrogen atom, a linear, branched or cyclic alkyl, aryl or aralkyl group. l is an integer of 1 to 3, m is an integer of 1 to 3,
n represents an integer of 1 to 6. 4. The polysiloxane has the following general formula (III):
The positive photoresist composition according to claim 1, wherein the structural unit represented by the formula (1) is contained as a siloxane structural unit having a group capable of decomposing with an acid to generate an alkali-soluble group. Embedded image In the formula (III), L ″ is -B-OCO-, -B-COO
-, -B-NHCO-, -B-NHCOO-, -BN
It represents at least one divalent linking group selected from HCONH-, -B-CONH- and -BS-. B represents a single bond or an arylene group. X represents a divalent linking group. Q represents an acid-decomposable group. n represents an integer of 1 to 6. 5. A polysiloxane comprising a siloxane unit having a group capable of decomposing both a structural unit represented by the general formula (II) and a structural unit represented by the general formula (III) with an acid to generate an alkali-soluble group. The positive photoresist composition according to claim 1, wherein the composition comprises: 6. A positive type comprising (a) the acid-decomposable polysiloxane according to any one of claims 1 to 5, and (b) a compound capable of decomposing upon exposure to generate an acid. Photoresist composition. 7. The phenolic compound (c1) wherein at least a part of the phenolic hydroxyl group contained in the molecule (c) is protected by an acid-decomposable group, or at least one of the carboxyl groups contained in the molecule. The positive photoresist composition according to claim 6, wherein the part contains an aromatic or aliphatic carboxylic acid compound protected by an acid-decomposable group.