JP2001166485A - Positive photoresist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive photoresist composition which gives a photoresist pattern having high sensitivity and high resolution and having a square cross section in the production of a semiconductor device. SOLUTION: The composition contains an acid-decomposable polysiloxane having both of a recurring structural unit expressed by general formula (I), e.g. formula (III) and a recurring structural unit expressed by general formula (II), e.g. formula (IV). Particularly, the composition preferably contains the aforementioned acid-decomposable polysiloxane, a compound which decomposes and produces an acid by exposure and a solvent which can dissolve both of them.

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 Streeter,
Kodak Micro electronics S
eminer Proceedings, 116 (19
1975) and the like, and an alkali-developable positive photoresist based on an alkali-soluble novolak resin is the mainstream of the current process. However, in recent years, as electronic devices have become more multifunctional and sophisticated, there has been a strong demand for finer patterns in order 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. Many of these problems have been found to be eliminated by using a multilayer resist system. For multi-layer resist systems, see Solid State Technology, 74 (19
81) [Solid State Technology
y, 74 (1981)],
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.
O2RIE for organic planarization film using inorganic intermediate layer as mask
(Reactive ion etching). 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.

[0005] In contrast to the three-layer resist method, the two-layer resist method requires the use of a resist having the properties of both 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. From the above background, a high-sensitivity, high-resolution positive-type photoresist excellent in oxygen plasma resistance that can be used as an upper-layer resist such as a two-layer resist method, particularly, an alkali-developing type resist that can be used without changing the current process. Development was desired.

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.

[0008]

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 pattern 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.

[0009]

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 repeating structural unit represented by the general formula (I),
A positive photoresist composition comprising an acid-decomposable polysiloxane having both repeating structural units represented by the general formula (II).

[0010]

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L is -A-NHCO-, -A-NHCOO
At least one selected from-, -A-NHCONH-
Represents two divalent linking groups. A represents a single bond, an alkylene group or an arylene group. X represents a single bond or a divalent linking group. Z is

[0012]

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Represents one of the groups represented by Y represents a hydrogen atom, or Y represents an alkyl group, an aryl group, or an aralkyl group. The atomic group represented by Y may be linear, branched, or cyclic. R represents a hydrogen atom. Alternatively, R represents a group capable of decomposing with an acid. l is 1
An integer of 1 to 3, and m also represents an integer of 1 to 3.

[0014]

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A ', X', and Z 'each refer to the same range as A, X, and Z in the general formula (I). (2) In the above general formula (I), L is - (CH _{2) 3}
-The positive photoresist composition according to the above (1), which is -NHCO-. (3) (a) the acid-decomposable polysiloxane according to the above (1) or (2), (b) a compound which decomposes upon exposure to generate an acid, and (c) the above (a) (b) A solvent capable of being dissolved together with the positive photoresist composition. (4) The positive photoresist composition as described in (3) above, wherein at least a part of the phenolic hydroxyl group contained in the molecule contains a phenolic compound protected by an acid-decomposable group. (5) The positive photoresist as described in (3) above, wherein at least a part of the carboxyl group contained in the molecule contains an aromatic or aliphatic carboxylic acid compound protected by an acid-decomposable group. Composition.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the polysiloxane used in the positive photoresist composition of the present invention will be described.
In the general formula (I), L represents -A-NHCO-, -A-
It represents NHCOO- or -A-NHCONH-. Among them, -A-NHCO- is preferable. A of the general formula (I) and A ′ of the general formula (II) represent a single bond, an alkylene group or an arylene group. Among them, an alkylene group having 1 to 6 carbon atoms or a phenylene group is preferable, and a propylene group is more preferable. X in the general formula (I) and
X ′ in (II) represents a single bond or a divalent linking group. Specific examples of the divalent linking group include, for example, 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, 6 ~
10 selected from the group consisting of 10 aromatic ring groups, aralkylene groups having 7 to 11 carbon atoms, ether groups, thioether groups, carbonyl groups, ester groups, amide groups, sulfonamide groups, urethane groups, urea groups, and sulfone groups Alternatively, a linking group composed of a combination of two or more is exemplified. Preferably it is a single bond or a C1-C6 alkylene group, More preferably, it is a C1-C4 linear alkylene group. Z of general formula (I) and general formula (II)
Z is

[0017]

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Represents one of the groups represented by R
Is a group that decomposes with an acid. In the -OR group in the formula Z, an ester group or the like may be formed together with the oxygen atom to which R is directly bonded, whereby the acid may be decomposed with an acid. An acid-decomposable atomic group may be partially contained to constitute a group which is decomposed by an acid.

Preferred examples of the alkylene group include methylene, ethylene, propylene, butylene and the like. 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 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, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group,
t-butyl group, n-pentyl group, i-pentyl group, n-
Examples include a hexyl group, a cyclohexyl group, a phenyl group, a naphthyl group, a benzyl group, a phenethyl group, and a naphthylmethyl group. Among them, a hydrogen atom and a methyl group are preferred.

L 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 group represented by the acid-decomposable group R of the acid-decomposable polysiloxane represented by the general formula (I) is -CR ¹
Examples include a group represented by R ² (OR ³ ), a methoxymethyl group, an ethoxymethyl group, a t-butyl group, a t-amyl group, a 1-methylcyclohexyl group, a trimethylsilyl group, and a t-butyldimethylsilyl group. The above R ¹ , 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 represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. It is. 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.

[0023]

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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 —CR ⁵ R
^{A group represented by 6} (OR ⁷ ), a t-butoxycarbonyl group,
t-butoxycarbonylmethyl group, t-butyl group, t-
Examples thereof include an amyl group, a 1-methylcyclohexyl group, a trimethylsilyl group, and a 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 a cyclic alkyl group. Further, R ⁶ and 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-butoxycarbonyl group, a t-butyl group, a trimethylsilyl group, a t-butyldimethylsilyl group, and a group represented by the following formula.

[0025]

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

The acid-decomposable polysiloxane of the present invention comprises
20 to 100 mol% in total of the structures of (I) and (II)
It is preferably contained, more preferably 40 to 100 mol%. The content ratio of (I) / (II) is 80/20
-20/80 is desirable. In the acid-decomposable polysiloxane of the present invention, the proportion of the phenolic OH protected by the acid-decomposable group is 10 to 90 mol%, more preferably 20 to 80%, particularly preferably 40 to 75%. . In this case, the term "mol%" means that the total of the phenolic structural units contained in the polysiloxane and the structural units that are decomposed by an acid to form phenolic OH groups is 100%, and the total Shows the mol% of the structural unit that becomes a phenolic OH group.

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

[0029]

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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.

The acid-decomposable polysiloxane having the structural unit represented by the general formula (I) or (II) is obtained by first synthesizing an alkali-soluble polysiloxane having a phenol structure at the terminal, and then decomposing the OH group by acid decomposition. It can be obtained by protecting with a sex group. The synthesis of an alkali-soluble polysiloxane as an intermediate is performed by converting a carboxylic acid compound having a phenol structure and a monosubstituted trialkoxysilane having an amino group at a terminal by a DCC method or a mixed acid anhydride method to form a phenol structure with a trialkoxysilane. After the amide linkage to the structure, if desired, the compound represented by the general formula (II)
It is obtained by adding a monosubstituted trialkoxysilane or a disubstituted dialkoxysilane to give structural units represented by I) to (IV), followed by condensation polymerization in the presence of water and an acid, or water and a base catalyst. Can be

Here, in order to increase the yield of the reaction, OH
A carboxylic acid compound having a phenol structure in which a group is protected and a monosubstituted trialkoxysilane having an amino group at a terminal are subjected to amide linkage of a phenol structure to a trialkoxysilane structure by a DCC method or a mixed acid anhydride method. , Followed by deprotection of the protecting group followed by condensation polymerization in the presence of water and an acid or water and a base catalyst, or amidation followed by condensation polymerization in the presence of a water and an acid or water and a base catalyst After that, deprotection may be performed. As the protecting group for OH, t-butoxycarbonyl (BOC), acetyl, alkoxy, benzyloxycarbonyl (Z) trialkylsilyl and the like can be used. Next, the OH group of the obtained alkali-soluble polysiloxane is protected with an acid-decomposable 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. Use of a siloxane unit having a structural unit represented by the above (III) or (IV) is preferable in view of solvent solubility, sensitivity, resolution, and rectangularity of a pattern. 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.

[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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[0041]

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[0042]

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[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, (d) a phenolic compound in which at least a part of the phenolic hydroxyl group contained in the (d1) molecule is protected by an acid-decomposable group, or (d2) 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 positive photoresist composition of the present invention contains an alkali-soluble polysiloxane having the same structure as the structure in which all the acid-decomposable groups of the acid-decomposable polysiloxane of the present invention are dissociated by acid decomposition. The content is preferably in the range of 5 to 50% by weight of the composition,
More preferably, it is 10 to 30% by weight.

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 that generate an acid upon irradiation with actinic rays or radiation used in the present invention include, for example, S.I. I. Schlesinger, Ph
otogr. Sci. Eng. , 18, 387 (19
74); S. Bal etal, Polymer,
21, 423 (1980); U.S. Pat. Nos. 4,069,055 and 4,069,
Nos. 056 and 27,992, JP-A-3-140140
Ammonium salts described in No. 1 and the like; C. Necker
et al, Macromolecules, 17, 2
468 (1984), C.I. S. Wen et al, T
eh, Proc. Conf. Rad. Curing A
SIA, p. 478 Tokyo, Oct (198
8), U.S. Patent Nos. 4,069,055 and 4,06
A phosphonium salt described in JP-A-9,056 and the like; V. C
riverello et al, Macromorecu
les, 10 (6), 1307 (1977), Che
m. & Eng. News, Nov. 28, p.
31 (1988); European Patent Nos. 104,143, 339,049, 410,201;
Iodonium salts described in J. 50848, JP-A-2-296514 and the like; V. Crivello etal,
Polymer J. et al. 17, 73 (1985),
J. V. Crivello et al. J. Org.
Chem. 43, 3055 (1978); R. W
att et al, J.A. Polymer Sci. ,
Polymer Chem. Ed. , 22,1789
(1984); V. Crivello et a
1, Polymer Bull. , 14, 279 (19
85); V. Crivello et al, Ma
cromorecules, 14 (5), 1141 (1
981); V. Crivello et al,
J. Polymer Sci. , Polymer Ch
em. Ed. , 17, 2877 (1979), European Patent Nos. 370,693, 161 and 811, and 41.
Nos. 0, 201, 339, 049 and 233, 567
Nos. 297,443 and 297,442; U.S. Pat. Nos. 3,902,114 and 4,933,377;
No. 4,760,013, No. 4,734,444, No. 2,833,827, Dokoku Patent No. 2,904,626
Nos. 3,604,580 and 3,604,581
, Sulfonium salts described in JP-A-7-28237, JP-A-8-27102 and the like. V. Crivello e
tal, Macromorecules, 10
(6), 1307 (1977); V. Crivel
lo et al. Polymer Sci. , Po
lymer Chem. Ed. , 17, 1047 (19
79) and the like. S. Wen e
tal, Teh, Proc. Conf. Ra
d. Curing ASIA, p. 478 Tokyo
o, Oct (1988), etc., onium salts such as arsonium salts, U.S. Pat. No. 3,905,815, JP-B-46-4605, JP-A-48-36281, JP-A-55-3270, JP-A-60-239736,
JP-A-61-169835, JP-A-61-16983
7, JP-A-62-258241, JP-A-62-212
No. 401, JP-A-63-70243, JP-A-63-2
Organic halogen compounds described in K. 98339 and the like; M
eieret al, J. et al. Rad. Curing, 13
(4), 26 (1986); P. Gill et
al, Inorg. Chem. , 19, 3007 (1
980); Astruc, Acc. Chem. Re
s. , 19 (12), 377 (1896);
Organic metal / organic halides described in JP-A-161445 and the like; Hayase et al, J. Mol. Polyme
r Sci. , 25, 753 (1987); Re
ichmanis et al, J. Mol. Polyme
r Sci. , Polymer Chem. Ed. ,
23, 1 (1985); Q. Zhu et a
1, J .; Photochem. , 36,85,39,3
17 (1987); Amit et al, Tet
rahedron Lett. , (24) 2205 (1
973); H. R. Barton et al,
J. Chem Soc. , 3571 (1965);
M. Collins et al, J. Mol. Che
m. Soc. , Perkin I, 1695 (1
975); Rudinstein et al, T
etrahedron Lett. , (17), 144
5 (1975); W. Walker et al
J. Am. Chem. Soc. , 110, 7170 (1
988); C. Busman et al, J. M .; I
imagingTechnol. , 11 (4), 191
(1985); M. Houlihan et a
1, Macromolecules, 21, 2001
(1988); M. Collinsetal,
J. Chem. Soc. Chem. Commun. ,
532 (1972); Hayase et a
1, Macromolecules, 18, 1799
(1985); Reichmanis et a
1, J .; Electrochem. Soc. , Soli
dState Sci. Technol. , 130
(6), F.R. M. Houlihan et al, Ma
cromolcules, 21, 2001 (198
8), European Patent Nos. 0290,750 and 046,08
Nos. 3,156,535, 271,851,0,388,343, U.S. Pat. No. 3,901,710
No. 4,181,531, JP-A-60-19853
8, a photoacid generator having an O-nitrobenzyl-type protecting group described in JP-A-53-133022 and the like; TUNO
OKA et al, Polymer Preprin
ts Japan, 35 (8); Berner
et al, J.A. Rad. Curing, 13 (4),
W. J. Mijs et al, Coating T
echnol. , 55 (697), 45 (198
3), Akzo, H .; Adachiet al, Pol
ymer Preprints, Japan, 37
(3), European Patent Nos. 0199,672 and 84,51
No. 5, No. 044, No. 115, No. 618, 564, No. 0
No. 101,122; U.S. Pat. No. 4,371,605;
No. 4,431,774, JP-A-64-18143
JP-A-2-245756, JP-A-3-14010
Compounds which generate sulfonic acid upon photolysis, such as iminosulfonate described in JP-A No. 9-91, etc.
66544, JP-A-2-71270 and the like, and disulfone compounds described in JP-A-3-103854 and 3-1.
And diazoketosulfone and diazodisulfone compounds described in JP-A Nos. 03856 and 4-210960.

Further, a group capable of generating an acid by these lights,
Alternatively, a compound having a compound introduced into the main chain or side chain of a polymer, for example, M.P. E. FIG. Woodhouse et
al, J. et al. Am. Chem. Soc. , 104,55
86 (1982); P. Pappas et a
1, J .; Imaging Sci. , 30 (5), 2
18 (1986); Kondo et al, Ma
cromol. Chem. , Rapid Commu
n. , 9, 625 (1988); Yamadaet
al, Makromol. Chem. , 152, 15
3, 163 (1972); V. Crivello
et al, J.A. Polymer Sci. , Pol
ymer Chem. Ed. , 17, 3845 (197
9), U.S. Pat. No. 3,849,137, Dokoku Patent No. 3
914407, JP-A-63-26653, JP-A-55
JP-A-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452,
JP-A-62-153853, JP-A-63-14602
Compounds described in No. 9 and the like can be used.

Further, V. N. R. Pilai, Syn
thesis, (1), 1 (1980); Abad
et al, Tetrahedron Lett. ,
(47) 4555 (1971); H. R. Bar
ton et al, J.M. Chem. Soc. ,
(C), 329 (1970); U.S. Pat.
No. 778, EP 126,712 and the like, compounds which generate an acid by light 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 are each independently
It represents a substituted or unsubstituted alkyl group or aryl group.
Preferably, an aryl group having 6 to 14 carbon atoms, 1 to 1 carbon atoms
And substituted derivatives thereof. Preferred substituents are those having 1 to 8 carbon atoms for the aryl group.
And an alkyl group having 1 to 8 carbon atoms, a nitro group, a carboxyl group, a hydroxy group and a halogen atom. The alkyl group is an alkoxy group having 1 to 8 carbon atoms, a carboxyl group or an alkoxycarbonyl group. is there.

[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.

[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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[0080]

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[0081]

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[0082]

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The onium salts represented by the general formulas (PAG3) and (PAG4) are known. W. Kn
apczyk et al, J. Mol. Am. Chem. So
c. , 91, 145 (1969); L. Mayco
k et al, J. et al. Org. Chem. , 35,2
532, (1970); Goethas eta
1, Bull. Soc. Chem. Belg. , 73,
546, (1964); M. Leicester,
J. Am. Chem. Soc. , 51, 3587 (19
29); V. Crivello et al, J. Mol.
Polym. Chem. Ed. , 18, 2677 (19
80), U.S. Pat. Nos. 2,807,648 and
No. 247,473 and JP-A-53-101,331.

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

[0085]

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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.

[0087]

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[0088]

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[0089]

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[0090]

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[0091]

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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.

In the phenolic compound used in the present invention, the phenolic hydroxyl group contained in the molecule (d) is partially or completely protected by an acid-decomposable group (acid-decomposable group). As the aromatic or aliphatic carboxylic acid compound in which the carboxyl group contained is partially or completely protected by a group capable of being decomposed 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.

The amount of the component (d) is preferably 2 to 50% by weight, more preferably 5 to 40% by weight, based on the polysiloxane of the present invention.
Particularly preferably, it is 10 to 30% by weight. Specific examples of the component (d) include the following compounds.

[0096]

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[0097]

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[0110]

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[0111]

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[0112]

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[0113]

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[0114]

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

[0116]

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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. )

[0118]

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[0119]

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[0120]

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[0121]

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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).

[0123]

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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.

[0125]

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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, by adding a spectral sensitizer as described below and sensitizing the photoacid generator to be used in a longer wavelength region than the deep ultraviolet where the photoacid generator used has no absorption, the chemically amplified positive resist of the present invention is obtained. 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
(C) A solution in which each of the above components is dissolved in a solvent in which the components are dissolved, and the solution is coated on a support. , 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, methoxypropionic acid Methyl, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate,
Propyl pyruvate, N, N-dimethylformamide,
Dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable, and these (c) solvents are used alone or as a mixture.

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 further the component (c), but an alkali-soluble resin may be added in order to further improve the film properties and heat resistance. As such an alkali-soluble resin, preferably, a phenolic hydroxyl group, a carboxylic acid group, a sulfonic acid group, an imide group, a sulfonamide group, an N-sulfonylamide group,
-A polymer having an acidic hydrogen atom having a pKa of 11 or less, such as a sulfonyl urethane 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 above-described resist composition film pattern 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.

[0144]

EXAMPLES Synthesis Example 1 <Synthesis of Polysiloxane (1 ′)>

[0145]

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After adding 28.7 g of diphenolic acid and 10.0 g of triethylamine to 200 ml of dried N, N-dimethylacetamide, the mixture was cooled to -20 ° C.
Thereto, 13.7 g of isobutyl chloroformate was added dropwise over 2 hours. The reaction was performed at 0 ° C. for 2 hours in a dry nitrogen atmosphere.
20 g of 3-aminopropyltrimethoxysilane was dripped there over 2 hours. Thereafter, the mixture was reacted at room temperature under a dry nitrogen atmosphere for 5 hours (this is referred to as a reaction solution A). Separately, 17.2 g of chloromethyltrimethoxysilane was added to 200 ml of dried N, N-dimethylacetamide, 15.2 g of 4-hydroxyphenylacetic acid, 3.0 g of potassium iodide and 16.0 g of DBU (1,8-diazabicyclo [5.4.0] -7-undecene) were added. The reaction was performed at 70 to 90 ° C. for 5 hours in a dry nitrogen atmosphere (this is referred to as a reaction liquid B). After the solution B was returned to room temperature, the above solution A was added, and 2 g of dimethylaminopyridine and 15 g of distilled water were added.
The reaction was performed at 30 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 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 5300, and the molecular weight was 100.
The content of the component of 0 or less was 5% by GPC area ratio.

<Synthesis of Polysiloxane (1)>

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Vacuum dried polysiloxane (1 ′) 20
g was dissolved in 100 ml of THF. After adding 4.8 g of t-butyl dicarbonate, 2.8 g of triethylamine was added dropwise over 1 hour, and further reacted at room temperature for 10 hours. The polymer was precipitated by adding it to 2 L of distilled water with stirring, and then dried in vacuum at room temperature to obtain the desired acid-decomposable polysiloxane 18.
g was obtained. The protection ratio of the OH group by ethyl vinyl ether was determined by NMR, which was 58%. The weight average molecular weight of this polymer was determined by GPC to be 610.
It was 0. The following polysiloxane was synthesized in the same manner.

[0150]

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[0151]

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Example 1 2 g of polysiloxane (1) as an acid-decomposable polysiloxane (component (a)) and triphenylsulfonium-2,4,6 as a compound capable of generating an acid upon exposure (component (b)) 0.08 g of triisopropylphenylsulfonate and 0.012 g of triphenylimidazole are dissolved in 19.2 g of propylene glycol monomethyl ether acetate, and 0.1 μm
Microfiltration was performed with a membrane filter. FHi-028D resist (Fujifilm Ohlin Co., Ltd., i-line resist) on silicon wafer, Canon Coater CDS
It was applied using -650 and baked at 90 ° C. for 90 seconds to obtain a uniform film having a thickness of 0.83 μm. Add another 200
After heating at 3 ° C. for 3 minutes, the film thickness became 0.71 μm.
Apply the silicon-containing resist prepared above on this,
The film was baked at 90 ° C. for 90 seconds and applied in a thickness of 0.20 μm. The wafer thus obtained was exposed to a KrF excimer laser stepper FPA-3000EX3 manufactured by Canon Inc. while changing the exposure amount and focus by mounting a resolving power mask. Thereafter, the film was heated in a clean room at 120 ° C. for 90 seconds, 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 a 0.15 μm line / space was resolved with a sensitivity of 32 mJ / cm ² . The rectangularity of the cross section is evaluated A
Met. 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 A was evaluated from 80 ° to 90 °, B was evaluated from 70 ° to less than 80 °, and C was evaluated from less than 70 °. Further, the wafer was subjected to an etching gas of oxygen using a ULVAC-made parallel plate type reactive ion etching apparatus at a pressure of 20 mTorr,
Etching was performed for 15 minutes under the conditions of an applied power of 100 mW / cm ² . The results were observed with a scanning electron microscope. 0.007μ dimensional shift for 0.15μm pattern
m.

Examples 2 to 14 The components (a) and (b) shown in Table 1 were used in place of the acid-decomposable polysiloxane (a) and the acid generator (b) in Example 1. A positive photoresist was prepared in the same manner as in Example 1 except for the above, and exposed, developed, and etched in the same manner as in Example 1. The results are summarized in Table 2.

[0154]

[Table 1]

[0155]

[Table 2]

Example 15 As an acid-decomposable siloxane (component (a)), 1.9 g of polysiloxane (1) was used.
As an acid generating compound (component (b)), 0.12 g of triphenylsulfonium-2,4,6-triisopropylphenylsulfonate, 0.01 of triphenylimidazole
2 g and compound example (18) (where R = —CH ₂ COO
A positive photoresist was prepared in the same manner as in Example 1 except that 0.19 g of C (CH ₃ ) ₃ ) 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.

[0157]

[Table 3]

[0158]

[Table 4]

Examples 16 to 28 In place of the acid-decomposable polysiloxane (a), the acid generator (b) and the solvent (c) in Example 15, the components (a) and (c) shown in Table 3 were used. A positive photoresist was prepared in the same manner as in Example 15 except that the components (b) and (c) were used, and exposed, developed and etched in the same manner as in Example 15. The results are summarized in Table 4.

Comparative Example 1 The following polysiloxane D-1 (Mw = 1380) was used instead of the polysiloxane of Example 1.
A positive photoresist was prepared in the same manner as in Example 1 except that 0) was used.
Etching was performed, and then observed with a scanning electron microscope as in Example 1. Table 5 shows the results.

Comparative Example 2 The following polysiloxane D-2 (Mw = 1030) was used instead of the polysiloxane of Example 1.
A positive photoresist was prepared in the same manner as in Example 1 except that 0) was used.
Etching was performed, and then observed with a scanning electron microscope as in Example 1. Table 5 shows the results.

Comparative Example 3 The following polysiloxane D-2 (Mw = 1030) was used in place of the polysiloxane of Example 15.
Except that (0) was used, a positive photoresist was prepared in the same manner as in Example 15, exposed, developed, and etched in the same manner as in Example 1, and then subjected to scanning electron microscopy as in Example 1. Observed. Table 5 shows the results.

[0163]

[Table 5]

The polysiloxane used in the above comparative example was
It is as follows.

[0165]

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From the results shown in Tables 1 to 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, Comparative Examples 1 to 3 not using the polysiloxane of the present invention
In the case of 3, the balance of the above characteristics is poor.

[0167]

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 F term (reference) 2H025 AA01 AA02 AA06 AA14 AB15 AB16 AB17 AC01 AD03 BE00 BE10 BG00 CB33 CB41 CB42 CC03 DA11 FA35

Claims (5)

[Claims] 1. A positive photoresist comprising an acid-decomposable polysiloxane having both a repeating structural unit represented by the general formula (I) and a repeating structural unit represented by the general formula (II). Composition. Embedded image L is -A-NHCO-, -A-NHCOO-, -AN
Represents at least one divalent linking group selected from HCONH-. A represents a single bond, an alkylene group or an arylene group. X represents a single bond or a divalent linking group. Z
Is Represents one of the groups represented by Y represents a hydrogen atom, or Y represents an alkyl group, an aryl group, or an aralkyl group. The atomic group represented by Y may be linear,
It may be branched or annular. R represents a hydrogen atom.
Alternatively, R represents a group capable of decomposing with an acid. l is an integer of 1 to 3,
m also represents an integer of 1 to 3. Embedded image A ′, X ′, and Z ′ each represent A of the general formula (I);
The same range as X and Z is generically referred to. 2. In the general formula (I), L is-(C
H _{2) 3} positive photoresist composition according to claim 1, wherein it is characterized in a -NHCO-. 3. A combination of (a) the acid-decomposable polysiloxane according to claim 1 or 2; (b) a compound capable of decomposing upon exposure to generate an acid; and (c) the above (a) and (b). And a solvent capable of being dissolved. 4. The positive photoresist composition according to claim 3, wherein at least a part of the phenolic hydroxyl group contained in the molecule contains a phenolic compound protected by an acid-decomposable group. 5. The positive-type photo according to claim 3, wherein at least a part of the carboxyl group contained in the molecule contains an aromatic or aliphatic carboxylic acid compound protected by an acid-decomposable group. Resist composition.