JP2001100420A - 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, giving a photoresist of 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 an acid decomposable polysiloxane containing at least a structural unit of formula I [where L is -A-OCO-, -A-COO-, -A-NHCO-, -A-NHCOO-, -A-NHCONH-, -A- CONH-,-A-OCONH- or -A-S-, A is a single bond or arylene, X is a divalent combining group, Q is H or an acid decornposable group (all symbols Q in the polysiloxane are not H) and (n) is an integer of 1-6].

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 the density and integration of semiconductor devices and the like, the line width and spacing of patterns have become extremely small.
Since dry etching has been adopted for substrate etching, high resolution and high dry etching resistance have been demanded for photoresists, and the majority of positive photoresists are nowadays. Was. In particular, among the positive photoresists, they have excellent sensitivity, resolution and dry etching resistance. For example, JC Strieta, Kodak Microelectronics Seminar Proceedings, No. 11
6 (1976) (JC Strieter, Kodak Micro ele
ctronics Seminar Proceedings, 116 (1976)
And the like, alkali-developable positive photoresists based on alkali-soluble novolak resins are the mainstream of current processes.

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. Further, in various types of exposure methods, there is a problem with the reduction of the minimum size. 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 proximity effect caused by backscattering of electrons causes the fine resist pattern The height to width ratio can no longer be increased.

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 flattening film by O2 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.

[0007] 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 imparted 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.

[0010]

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.

[0011]

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 positive photoresist composition comprising at least an acid-decomposable polysiloxane containing a structural unit represented by the following general formula (I).

[0012]

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In the formula (I), L is -A-OCO-, -A-
COO-, -A-NHCO-, -A-NHCOO-,-
A-NHCONH-, -A-CONH-, -A-OCO
Represents at least one divalent linking group selected from NH- and -AS-. A represents a single bond or an arylene group. X represents a divalent linking group. Q represents a hydrogen atom or an acid-decomposable group, but in the polysiloxane containing the formula (I), not all Q are hydrogen atoms. n represents an integer of 1 to 6.

(2) The positive photoresist composition according to the above (1), wherein in the structural unit represented by the general formula (I), X is an aromatic ring group or an alicyclic group.

(3) An acid-decomposable polysiloxane containing at least both a structural unit represented by the general formula (I) described in the above (1) and a structural unit represented by the following general formula (II): A positive photoresist composition comprising:

[0016]

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

[0018]

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R represents a hydrogen atom or a group capable of decomposing with an acid. Y represents a hydrogen atom, a linear, branched or cyclic alkyl, aryl or aralkyl group. l represents an integer of 1 to 3, m represents an integer of 1 to 3, and n represents an integer of 1 to 6.

(4) (a) An acid-decomposable polysiloxane as described in any of (1) to (3) above, and (b) a compound which decomposes upon exposure to generate an acid. Positive photoresist composition.

(5) Further, (c) a phenolic compound in which a phenolic hydroxyl group contained in the molecule is partially or completely protected by a group capable of being decomposed by an acid, or a carboxyl group contained in the molecule is an acid. (4) characterized in that it contains an aromatic or aliphatic carboxylic acid compound partially or completely protected by a group capable of decomposing.
The positive photoresist composition as described in the above.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the polysiloxane of the present invention will be described. The acid-decomposable polysiloxane of the present invention contains at least the siloxane structural unit represented by the general formula (I), and may further contain the siloxane structural unit represented by the general formula (II) as a copolymer component. .

L in the general formulas (I) and (II) is-
A-OCO-, -A-COO-, -A-NHCO-,-
A-NHCOO-, -A-NHCONH-, -A-CO
NH-, -A-OCONH- and -AS- (where A
Represents a single bond or an arylene group), and represents a divalent linking group selected from the group consisting of -NHCO- and-
NHCONH- is preferred, and -NHCO- is particularly preferred. 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 (I) and (II) 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, an alicyclic 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 aromatic ring groups and an aralkylene group having 7 to 11 carbon atoms, and a linking group in which two or more kinds are linked. Note that X is X
And Z may contain one or more groups selected from —O—, —CO—, —S—, —SO ₂ —, and —CH ＝ CH—. Preferred examples of the alkylene group include methylene, ethylene, propylene, and butylene. Preferable examples of the alicyclic group include a cyclohexylene group and a norbornene group. Preferable examples of the aromatic ring 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) and (II), n is 1
-6, preferably 1-3. In the general formula (II), 1 represents an integer of 1 to 3, preferably 1 to 2,
m represents an integer of 1 to 3, preferably 1 to 2.

The acid-decomposable group of the acid-decomposable polysiloxane represented by the general formula (I) includes a group represented by -CR ¹ R ² (OR ³ ), a methoxymethyl group, an ethoxymethyl group, a 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 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-butyl group, a trimethylsilyl group, a t-butyldimethylsilyl group, an ethoxymethyl group, and a group represented by the following formula.

[0028]

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

The acid-decomposable group of the acid-decomposable polysiloxane represented by the general formula (II) includes a group represented by —CR ⁵ R ⁶ (OR ⁷ ), a t-butoxycarbonyl group and a t-butoxycarbonylmethyl Group, t-butyl group, t-amyl group, 1
-Methylcyclohexyl group, trimethylsilyl group, t-
A butyldimethylsilyl group can be mentioned. The above R ⁵ R ⁶ , which may be the same or different, are a hydrogen atom or a C 1-6
R ^{7 is} a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. Further, R ⁶ R ⁷ may be bonded to form a ring structure, preferably a ring structure having 6 ring members. Specific examples of preferred acid-decomposable groups include t-butoxycarbonyl group, t-
Examples thereof include a butyl group, a trimethylsilyl group, a t-butyldimethylsilyl group, and a group represented by the following formula.

[0031]

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

The acid-decomposable polysiloxane of the present invention comprises 10 structural units in which at least a part of the carboxyl group of the structural unit represented by the general formula (I) is protected by an acid-decomposable group.
１００100 mol%, preferably from 30 to 70 mol%.
More preferably, it is contained by mol%. Further, the acid-decomposable polysiloxane containing both the structural units of the general formulas (I) and (II) has a structural unit of the general formula (I) of 10 to 9%.
It is preferable to contain 0 mol%, and 10 to 90 mol% of a unit in which at least a part of the phenolic hydroxyl group of the structural unit represented by the general formula (II) is protected by an acid-decomposable group.

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

[0035]

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Here, W, W ¹ and W ² represent groups 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 specific examples of these groups include methyl, ethyl, n-propyl, i-propyl, n
-Butyl, i-butyl, t-butyl, n-pentyl, n
-Hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, cyclohexyl, phenyl, naphthyl, benzyl, naphthylmethyl.
The substituents of these groups include a halogen atom,
To 6 alkoxy groups, phenoxy groups, hydroxyl groups and the like. Note that W ¹ and W ² may be the same or different.

When L is —NHCO—, the acid-decomposable polysiloxane having a structural unit represented by the general formula (I) is obtained by combining a monosubstituted trialkoxysilane having an amino group at a terminal with an acid anhydride. After the reaction, if necessary, a monosubstituted trialkoxysilane or a disubstituted dialkoxysilane for providing a structural unit represented by the general formula (III) and / or (IV) is added, and then water and an acid, or It can be obtained by protecting an alkali-soluble polysiloxane obtained by condensation polymerization in the presence of water and a base catalyst with an acid-decomposable group.

The acid anhydride includes succinic anhydride,
Methyl succinic anhydride, dimethyl succinic anhydride, cyclohexane dicarboxylic anhydride, methyl cyclohexyl dicarboxylic anhydride, itaconic anhydride, tetrahydrophthalic anhydride, norbornene dicarboxylic anhydride, cantharidin, methyl norbornene dicarboxylic anhydride,
Maleic anhydride, citraconic acid anhydride, bromomaleic anhydride, dichloromaleic anhydride, aconitic anhydride, glutaric anhydride, methylglutaric anhydride, dimethylglutaric anhydride, ethylmethylglutaric anhydride Use of tetramethylene glutaric anhydride, phthalic anhydride, methyl phthalic anhydride, dichlorophthalic anhydride, tetrachlorophthalic anhydride, hydroxyphthalic anhydride, nitrophthalic anhydride, naphthalenedicarboxylic anhydride Can be.

The acid-decomposable polysiloxane having the structural units represented by the above general formulas (I) and (II) includes, for example, when L is —OCO—, a (chloroalkyl) trialkoxysilane and a phenol structure In the presence of a base catalyst (in this case, a salt such as potassium iodide may be added to accelerate the reaction)
After that, trialkoxysilane to give the general formula (I) is optionally added to the above-mentioned general formula (III) and / or (I
After adding a monosubstituted trialkoxysilane or a disubstituted dialkoxysilane to give the structural unit represented by V), condensation polymerization is performed in the presence of water and an acid, or water and a base catalyst, and then an acid-decomposable group is formed. It can be obtained by introducing.

L is -COO-, -NHCO-, -NHC
OO-, -NHCONH-, -CONH-, -OCON
In the case of H- or -S-, a carboxyl group at each terminal,
It can be obtained by using a trialkoxysilane having an amino group or a mercapto group.

Examples of the method for introducing the acid-decomposable group include an acid-catalyzed reaction with a vinyl ether compound corresponding to the acid-decomposable group, di-t-butyl dicarbonate, trimethylsilyl chloride,
Alternatively, it can be obtained by using a known reaction such as a base catalyzed reaction with t-butyldimethylsilyl chloride.

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

[0043]

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[0044]

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[0045]

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[0046]

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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 a carboxyl group contained in the molecule. Some may contain an aromatic or aliphatic carboxylic acid compound protected by an acid-decomposable group.

Further, the compounds represented by the general formulas (III) and / or (I
Use of a polysiloxane having a structural unit represented by V) is preferable in terms of solvent solubility, sensitivity, resolution, and rectangularity of the pattern. Further, the acid-decomposable polysiloxane of the present invention may contain an alkali-soluble polysiloxane from which all the acid-decomposable groups have been removed in the range of 5 to 50% by weight 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.

Other compounds which generate an acid upon irradiation with actinic rays or radiation used in the present invention include, for example, SI Schlesinger, Photogr. Sci. En.
g., 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), CS Wen et al, Teh, Pr.
oc.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 JV Crivello et al, Macromorec
ules, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 2
8, p. 31 (1988), EP 104,143, EP 339,049,
No. 410,201, JP-A-2-150848, iodonium salts described in JP-A-2-296514, etc., JV Crivello et al, Poly
mer J. 17, 73 (1985), JV Crivello et al. J. Org.
Chem., 43, 3055 (1978), WR Watt et al, J. Polyme
r Sci., Polymer Chem. Ed., 22, 1789 (1984), JVC
rivello et al, Polymer Bull., 14, 279 (1985), JV
Crivello et al, Macromorecules, 14 (5), 1141 (198
1), JV Crivello et al, J. Polymer Sci., Polymer
Chem. Ed., 17, 2877 (1979), EP 370,693,
Nos. 161,811, 410,201, 339,049, 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,
No. 3,604,581, JP-A-7-28237, sulfonium salts described in JP-A-8-27102, etc., JV Crivello etal, Macromorecu
les, 10 (6), 1307 (1977), JV Crivello et al, J. P.
olymerSci., Polymer Chem.Ed., 17, 1047 (1979) and the like, CS Wen et al, Teh, Proc.
Onium salts such as arsonium salts described in Conf. Rad. Curing ASIA, p. 478 Tokyo, Oct (1988), U.S. Pat.
5,815, JP-B-46-4605, JP-A-48-36281, JP-A-Showa
No. 55-32070, JP-A-60-239736, JP-A-61-169835,
JP-A-61-169837, JP-A-62-58241, JP-A-62-2124
No. 01, JP-A-63-70243, and organic halogen compounds described in JP-A-63-298339, K. Meier et al, J. Rad. Curi
ng, 13 (4), 26 (1986), TP Gill et al, Inorg.
m., 19, 3007 (1980), D. Astruc, Acc. Chem. Res., 19
(12), 377 (1896), and organometallic / organic halides described in JP-A-2-14145, S. Hayase et al, J. Polymer
Sci., 25, 753 (1987), E. Reichmanis et al, J. Pholyme
r Sci., Polymer Chem. Ed., 23, 1 (1985), QQ Zhu et
al, J. Photochem., 36, 85, 39, 317 (1987), B. Amit
et al, Tetrahedron Lett., (24) 2205 (1973), DHR
Barton et al, J. Chem Soc., 3571 (1965), PM Coll
ins et al, J. Chem. Soc., Perkin I, 1695 (1975), M.
Rudinstein et al, Tetrahedron Lett., (17), 1445 (19
75), JW Walker et al J. Am. Chem. Soc., 110, 717
0 (1988), SC Busman et al, J. Imaging Technol., 1
1 (4), 191 (1985), HM Houlihan et al, Macormolecul
es, 21, 2001 (1988), PM Collinsetal, J. Chem. So
c., Chem. Commun., 532 (1972), S. Hayase et al, Macro
molecules, 18, 1799 (1985), E. Reichmanis et al, J.
Electrochem. Soc., Solid State Sci. Technol., 130
(6), FM Houlihan et al, Macromolcules, 21, 2001 (1
988), European Patent Nos. 0290,750, 046,083, 156,535
No. 271,851, No. 0,388,343, U.S. Pat.No. 3,901,71
No. 0, 4,181,531, JP-A-60-198538, JP-A-53-13
No. 3022, etc., a photoacid generator having an O-nitrobenzyl-type protecting group, M. TUNOOKA et al, Polymer Preprints Ja
pan, 35 (8), G. Berner et al, J. Rad. Curing, 13 (4),
WJ Mijs et al, Coating Technol., 55 (697), 45 (1
983), Akzo, H. Adachi et al, Polymer Preprints, Jap
an, 37 (3), European Patent Nos. 0199,672, 84,515, 044,
No. 115, No. 618,564, No. 0101,122, U.S. Pat.No. 4,371,
605, 4,431,774, JP-A-64-18143, JP-A 2-2
No. 45756, compounds that generate sulfonic acid upon photodecomposition represented by iminosulfonate and the like described in JP-A-3-140109 and the like, described in JP-A-61-166544, JP-A-2-71270 and the like Disulfone compound, JP-A-3-103854, JP-A-3-103856
And the diazoketosulfone and diazodisulfone compounds described in JP-A Nos. 4-210960 and 4-210960.

Further, a group capable of generating 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.
maging Sci., 30 (5), 218 (1986), S. Kondo et al, Mak
romol. Chem., Rapid Commun., 9, 625 (1988), Y. Yama
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 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 (PAG)
An S-triazine derivative represented by 2).

[0056]

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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
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.

[0058]

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[0059]

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[0060]

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

[0062]

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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.

[0065] 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 through a single bond or a substituent.

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

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The above-mentioned 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. G.
oethas et al, Bull. Soc. Chem. Belg., 73, 546, (19
64), HM Leicester, J. Am. Chem. Soc., 51, 3587.
(1929), JV Crivello et al, J. Polym. Chem. Ed.,
18, 2677 (1980), U.S. Pat.Nos. 2,807,648 and 4,24
No. 7,473, 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).

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Where 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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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) 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.

The (c) phenolic compound used in the present invention in which the phenolic hydroxyl group contained in the molecule is partially or completely protected by a group capable of decomposing by an acid (acid-decomposable group), or As the aromatic or aliphatic carboxylic acid compound in which the carboxyl group contained is partially or completely protected by a group capable of decomposing by an acid (acid-decomposable group), for example, a molecular weight containing 2 to 7 aromatic rings 1
86 to 1500 aromatic compounds, or 20 to 100% of hydroxyl groups of a phenolic compound selected from hydroxystyrene copolymers having a weight average molecular weight in the range of 2000 to 20,000 as measured by GPC method, wherein an acid-decomposable group is contained. And the like protected by the above.

Here, the acid-decomposable group is represented by the general formula (II)
Is the same as the acid-decomposable group as the protective group in which the phenolic hydroxyl group of the alkali-soluble polysiloxane represented by is protected to form an acid-decomposable polysiloxane, the details of which have already been described.

The amount of the component (c) is preferably from 1 to 40% by weight, more preferably from 2 to 30% by weight, particularly preferably from 5 to 20% by weight, based on the polysiloxane of the present invention. It is.

Specific examples of the component (c) include the following compounds.

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

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This is 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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An organic basic compound can be added to the composition of the present invention. 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).

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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.

[0127]

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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.

Particularly preferred compounds are 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.

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 the wavelength region longer than 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 which promote the solubility in a developer include polyhydroxy compounds. 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.

The developer for the positive photoresist composition of the present invention includes, for example, 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, the organic polymer film is etched as a second step. 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 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.

[0146]

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-4 ′) 22.1 g of 3-aminopropyltrimethoxysilane was
After adding to 200 ml of dried N, N-dimethylacetamide, 16.1 g of norbornene dicarboxylic anhydride was added.
Was added. The reaction was carried out at 100 ° C. for 5 hours in a dry nitrogen atmosphere, and the reaction solution was returned to room temperature (this is called a reaction intermediate A solution). 20 g of phenyltrimethoxysilane, 2 g of dimethylaminopyridine and 15 g of distilled water were added to solution A,
For 3 hours and then at 130 to 140 ° C. for 12 hours. After the reaction solution was neutralized with dilute hydrochloric acid, it was poured into 3 L of distilled water with 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 with stirring,
The lower layer was reprecipitated in 2 L of distilled water to obtain a white polymer. When the average molecular weight of this polymer was measured by GPC (polystyrene standard), the weight average molecular weight was 3900, and the content of components having a molecular weight of 1,000 or less was 14% by GPC area ratio.

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Synthesis Example 2: Synthesis of Polysiloxane (C-4) 20 g of vacuum-dried polysiloxane (C-4 ′) was added to TH.
After dissolving in 100 ml of F, 4.3 g of tetrahydropyranyl ether and 20 g of p-toluenesulfonic acid monohydrate 20
mg was added and reacted at room temperature for 10 hours. After quenching the reaction 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 desired polysiloxane (C-4). N
The degree of protection with tetrahydropyranyl ether as determined by MR was 91%. When the average molecular weight of this polymer was measured in the same manner as in Synthesis Example 1, the weight average molecular weight was 4,600.

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Synthesis Example 3: Synthesis of polysiloxane (C-11 ′) After adding 20 g of 3-chloropropyltrimethoxylane to 200 ml of dry N, N-dimethylacetamide, 38.7 g of diphenolic acid and iodide Potassium 3.0
g and DBU (1,8-diazabicyclo [5.4.0]
1-7Og of (-7-undecene). The reaction was carried out at 70 ° C. to 90 ° C. for 5 hours in a dry nitrogen atmosphere (this is referred to as a reaction intermediate B liquid). After the solution B was returned to room temperature, 2 g of dimethylaminopyridine and 15 g of distilled water were added to the solution A described in Synthesis Example 1 above, and the mixture was added at 50 ° C. for 3 hours.
Then, the reaction was carried out at 130 to 140 ° C. for 12 hours. After neutralizing the reaction solution with dilute hydrochloric acid, it was poured into 3 L of distilled water with stirring.
A white powdery polymer was obtained. This is acetone 200m
Then, distilled water was added with stirring to remove the oligomer component of the polymer, and the lower layer was reprecipitated in 2 L of distilled water to obtain a white polymer. When the average molecular weight of this polymer was measured by GPC (polystyrene standard), the weight average molecular weight was 3300, and the content of components having a molecular weight of 1,000 or less was 8% by GPC area ratio.
%Met.

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Synthesis Example 4 Synthesis of Polysiloxane (C-11) After dissolving 20 g of polysiloxane (C-11 ′) dried under vacuum in 100 ml of THF, 3.3 g of ethyl vinyl ether and p-toluenesulfonic acid monohydrate were dissolved. 20mg Japanese
Was added and reacted at room temperature for 10 hours. After the reaction was quenched by adding triethylamine, the solution was poured into 2 L of distilled water with stirring to precipitate a polymer, followed by drying under reduced pressure at room temperature to obtain 17 g of the target polysiloxane (C-11).
The protection ratio by ethyl vinyl ether was determined by NMR and found to be 65%. When the average molecular weight of this polymer was measured in the same manner as in Synthesis Example 3, the weight average molecular weight was 3650.

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Synthesis Example 5: Synthesis of polysiloxane (C-18 ') The intermediate A solution of Synthesis Example 1, the intermediate B solution of Synthesis Example 3, 20 g of phenyltrimethoxysilane, 2 g of dimethylaminopyridine, and 23 g of distilled water Was added and reacted at 50 ° C. for 3 hours, and then at 130 to 140 ° C. for 12 hours. After neutralizing the reaction solution with dilute hydrochloric acid, it was poured into 3 L of distilled water with 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 with stirring, and the lower layer was distilled water 2
The precipitate was reprecipitated in L to obtain a white polymer. When the average molecular weight of this polymer was measured by GPC (polystyrene standard), it was 4500 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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Synthesis Example 6: Synthesis of Polysiloxane (C-18) Polysiloxane (C-18 ′) was dried under vacuum, and then 20 g thereof was dissolved in 100 ml of THF. Dicarbonate
After adding 4.8 g of -butyl, triethylamine 2.8 was added.
g was added dropwise over 1 hour, and further reacted at room temperature for 10 hours. After pouring into 2 L of distilled water with stirring to precipitate the polymer, the polymer was dried under reduced pressure at room temperature to obtain 18.2 g of the target polysiloxane (C-18). The t-BOC conversion was determined by NMR to be 72%. When the average molecular weight of this polymer was measured in the same manner as in Synthesis Example 5, it was 5,100.

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Example 1 2 g of polysiloxane (C-4) was used as the acid-decomposable polysiloxane (component (a)) and triphenylsulfonium was used as the compound capable of generating an acid upon exposure (component (b)).
0.08 g of 2,4,6-triisopropylphenylsulfonate and 0.012 g of triphenylimidazole
Was dissolved in 19.2 g of propylene glycol monomethyl ether acetate, and finely filtered through a 0.1 μm membrane filter. FHi-028 on silicon wafer
D resist (a resist for i-line, manufactured by Fujifilm Ohlin Co.) was applied using a coater CDS-650 manufactured by Canon, and baked at 90 ° 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 thereon, baked at 90 ° C. for 90 seconds, and applied to a thickness of 0.20 μm.

The wafer obtained in this way was 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 0.15 μm at a sensitivity of 37 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.
Those less than ° 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. Dimension shift of 0.15 μm pattern is 0.00
It was 5 μm.

Examples 2 to 14 In place of the acid-decomposable polysiloxane (component (a)) and component (b) in Example 1, the polysiloxanes (component (a)) and component (b) shown in Table 1 were used, respectively. A positive photoresist was prepared in exactly the same manner as in Example 1 except that was used, and exposed, developed and etched in the same manner as in Example 1. The obtained resist performance is summarized in Table 2.

Example 15 As an acid-decomposable siloxane (component (a)), 1.9 g of polysiloxane (C-11) 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 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 3 shows the prepared resists, and Table 4 shows the evaluation results.

Examples 16 to 28 Except that the siloxane, component (b) and component (c) shown in Table 3 were used instead of the acid-decomposable siloxane, component (b) and component (c) in Example 15, respectively. Is Example 1
A positive photoresist was prepared exactly in the same manner as in Example 5, and exposed, developed and etched in the same manner as in Example 15. Table 4 summarizes the obtained resist properties.

Comparative Example 1 A resist shown in Table 7 was prepared by using the following polysiloxane D-1 instead of the polysiloxane of Example 1. Coating, exposure, development and etching were performed in exactly the same manner as in Example 1, and observed with a scanning electron microscope as in Example 1. The results are shown in Table 8.

Comparative Example 2 The following polysiloxane D-2 was used in place of the polysiloxane of Example 1 to prepare a resist shown in Table 7. The coating, exposure, development, and etching treatments were performed in the same manner as in Example 1. Then, it was observed with a scanning electron microscope in the same manner as in Example 1. The results are shown in Table 8. The polysiloxane used in the above comparative example is as follows.

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[0167]

[Table 1]

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[Table 2]

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[Table 3]

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[Table 4]

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[Table 5]

[0172]

[Table 6]

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[Table 7]

[0174]

[Table 8]

From the results shown in Tables 2, 4 and 5, the following is clear. The positive photoresist composition of the present invention 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.

[0176]

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 the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/027 H01L 21/30 502R 573 F Term (Reference) 2H025 AA01 AA02 AA03 AA09 AB08 AB15 AB16 AB17 AD03 BE00 BE10 BG00 CC20 DA13 FA03 FA12 FA17 FA41 4J002 CP03W CP03X CP05W CP05X CP09W CP09X EJ017 EU186 EU226 FD206 FD207 GP03 5F046 NA05 NA17

Claims (5)

[Claims] 1. A positive photoresist composition comprising an acid-decomposable polysiloxane containing at least a structural unit represented by the following general formula (I). Embedded image In the formula (I), L represents -A-OCO-, -A-COO-,-
A-NHCO-, -A-NHCOO-, -A-NHCO
NH-, -A-CONH-, -A-OCONH- and-
Represents at least one divalent linking group selected from AS-. A represents a single bond or an arylene group. X represents a divalent linking group. Q represents a hydrogen atom or an acid-decomposable group, but not all Qs are hydrogen atoms in the polysiloxane containing the general formula (I). n represents an integer of 1 to 6. 2. The positive photoresist composition according to claim 1, wherein in the structural unit represented by the general formula (I), X is an aromatic ring group or an alicyclic group. 3. A compound of the formula (I) according to claim 1
A positive photoresist composition comprising an acid-decomposable polysiloxane containing both a structural unit represented by the following general formula (II) and a structural unit represented by the following general formula (II): Embedded image In the formula (II), L represents -A-OCO-, -A-COO-,-
A-NHCO-, -A-NHCOO-, -A-NHCO
NH-, -A-CONH-, -A-OCONH- and-
Represents at least one divalent linking group selected from AS-. A represents a single bond or an arylene group. X represents a divalent linking group. Z is R represents a hydrogen atom or a group capable of decomposing with 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. A positive-type photo-curable composition comprising: (a) the acid-decomposable polysiloxane according to claim 1, and (b) a compound capable of decomposing upon exposure to generate an acid. Resist composition. (C) a phenolic compound in which a phenolic hydroxyl group contained in the molecule is partially or completely protected by an acid-decomposable group, or a carboxyl group contained in the molecule is converted to an acid The positive photoresist composition according to claim 4, further comprising an aromatic or aliphatic carboxylic acid compound partially or completely protected by a decomposable group.