JPH11327144A - Positive photosensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive photosensitive composition having a high sensitivity to an ArF eximer laser beam and a sufficinet dry etching resistance by containing resin containing a polymer including a specified structure as a structure unit and optical acid generating agent. SOLUTION: This composition contains a compound generating acid when being irradiated with an active optical beam or radiation, and resin having a divalent multi-ring fat ring type unit in the principal chain in its polymer. In the formulae, R1 -R4 are independently hydrogen atom, halogen atom, group dissolved by the action of acid, or -Z-COOR5 , respectively, and R5 is hydrogen atom or alkyl group, Z is single bond, or -CH2 - group, R7 , R8 are independently hydrogen atom or methyl group, respectively, Y is oxygen atom, sulfur atom or -N(R6 )- group, R6 is hydrogen atom, alkyl group, group dissolved with the action of acid, or -X-COOR5 group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photosensitive composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal and a thermal head, and other photofabrication processes. Is far ultraviolet,
The present invention relates to a positive photosensitive composition suitably used for fine processing of a semiconductor device using short-wavelength light energy rays such as X-rays and electron beams, and particularly suitable for fine processing of a semiconductor device using an ArF excimer laser. The present invention relates to a positive photosensitive composition used.

[0002]

2. Description of the Related Art In recent years, high integration of semiconductor integrated circuits has progressed, and LSIs and VLSIs have been put into practical use, and the minimum pattern width of integrated circuits has reached a sub-half micron area.
Further miniaturization is progressing. Therefore, the demand for photolithography technology for forming a fine pattern is becoming more and more severe. As one of means for miniaturizing a pattern, it is known to shorten the wavelength of exposure light used when forming a resist pattern. For example, in the manufacture of a DRAM having a degree of integration of up to 64 Mbits, an i-line (365 nm) of a high-pressure mercury lamp has been used as a light source until now. In the mass production process of 256 Mbit DRAM, KrF excimer laser (248 nm) is put to practical use as an exposure light source instead of i-line, and a shorter wavelength light source is studied for the purpose of manufacturing a DRAM having an integration degree of 1 Gbit or more. ArF excimer laser (193n)
m), the use of F ₂ excimer laser (157 nm), X-rays and electron beams is considered to be effective (Takumi Ueno,
"Short Wavelength Photoresist Materials-Fine Processing for ULSI-", Bunshin Publishing, 1988).

In particular, an ArF excimer laser is positioned as a next-generation exposure technology, and development of a resist having high sensitivity, high resolution, and excellent dry etching resistance for ArF excimer laser exposure is desired. As a conventional resist material for i-line and KrF excimer laser exposure, a resist containing an aromatic polymer is widely used in order to obtain high dry etching resistance. For example, a novolak resin-based resist or a polyvinylphenol-based resist is used. Chemically amplified resists are known. However, since the aromatic ring introduced for the purpose of imparting dry etching resistance hardly transmits light in the wavelength range of ArF excimer laser light, it is difficult to expose even the bottom of the resist film. Did not provide a good pattern in cross section.

As a solution to the problem of resist transparency, it is known that an aliphatic polymer containing no aromatic ring, for example, polymethyl methacrylate may be used (J. Vac. Sci. Technol., B9, 3357 (1991)). However, such a polymer cannot be practically used because sufficient dry etching resistance cannot be expected. As described above, in developing a resist material for ArF excimer laser exposure, it is the greatest challenge to achieve both improved transparency and high dry etching resistance. Therefore, the fact that a resist containing an alicyclic hydrocarbon group instead of an aromatic ring shows the same resistance to dry etching as an aromatic group and has a small absorption at 193 nm, Proc. SPIE,
1672, 66 (1992), and in recent years the use of this polymer has been energetically studied.

[0005] Originally, attempts to apply a polymer containing an alicyclic hydrocarbon group to a resist have been made for a long time. For example, JP-A-60-195542, JP-A-1-174743, and JP-A-2-5975.
No. 1 discloses norbornene-based polymers,
JP-A-2-46045 discloses various alkali-soluble resins having a cyclic aliphatic hydrocarbon skeleton and a maleic anhydride unit. Further, JP-A-5-80515 discloses a copolymer of norbornene and an acrylic acid ester protected with an acid-decomposable group, JP-A-4-39665, JP-A-5-265212,
JP-A-5-80515, JP-A-7-234511 discloses a copolymer having an adamantane skeleton in a side chain, and JP-A-7-252324
JP-A-9-221526 discloses a compound in which an aliphatic cyclic hydrocarbon group having a carbon number of 7 to 12 having a bridged cyclic hydrocarbon group is linked to a side chain of a polymer, for example, tricyclo [5,2,
1,0 ^2,6 ] decane dimethylene group, tricyclo [5,
2,1,0 ^2,6 ] decanediyl group, norbornanediyl group, norbornanedimethyl group and adamantanediyl group are disclosed. JP-A-7-199467 discloses tricyclodecanyl group, dicyclopentenyl group, dicyclopentenyloxy group. A compound in which an ethyl group, a norbornyl group, or a cyclohexyl group is linked to a side chain of a polymer is disclosed.

Further, JP-A-9-325498 discloses a polymer having a cyclohexane and isobornyl skeleton in the main chain. Further, JP-A-9-230595 and JP-A-9-244247 disclose a polymer.
No., JP-A-10-10739, WO97 / 33198, EP794458, EP7892
No. 78 discloses a polymer in which various cyclic olefins such as dicycloolefin are introduced into the main chain.
No. 5, JP-A-9-230597 discloses that a compound having a menthyl group or a menthyl derivative group in a terpenoid skeleton is preferable. However, since the system becomes extremely hydrophobic as a detrimental effect of introducing an alicyclic hydrocarbon moiety, tetramethylammonium hydroxide (hereinafter referred to as TMAH), which has been widely used as a resist developing solution, is conventionally used.
There are phenomena such as difficulty in developing with an aqueous solution and peeling of the resist from the substrate during development.

[0007] In order to cope with such hydrophobicity of the resist, studies have been made to mix an organic solvent such as isopropyl alcohol in a developing solution. Although some results have been obtained, there is concern about swelling of the resist film and the process becomes complicated. However, the problem has not always been solved. In the approach of improving the resist itself, many measures have been taken to supplement hydrophobic alicyclic hydrocarbon sites by introducing a hydrophilic group. In general, measures have been taken to copolymerize monomers having a carboxylic acid moiety such as acrylic acid or methacrylic acid with monomers having an alicyclic hydrocarbon group. Although there is a direction to improve the dry etching resistance, dry etching resistance deteriorates,
Furthermore, there are many problems such as a significant decrease in resist film thickness, and the above problem has not been solved. Furthermore,
In JP-A-7-234511, a monomer having a hydroxyl group or a cyano group in the molecule instead of a carboxylic acid group such as HEMA or acrylonitrile is copolymerized with a monomer having an alicyclic hydrocarbon group. Has tried to solve the developing property, but the result has been completely insufficient without seeing the solution.

Recently, J. Photopolym. Sci., Tech.,
Vol.9,509 (1996) and J.Photopolym.Sci., Tech., Vol.1
As described in U.S. Pat. No. 0,545 (1997), improvement in substrate adhesion has been studied by focusing on a lactone structure such as mevalonic lactone. However, the developing property is insufficient, such as the necessity of an overcoat layer which complicates the process for securing the developing property, and the substrate adhesion is also insufficient.
In JP-A-8-289626, a monomer having both a carboxylic acid group and an alicyclic hydrocarbon moiety in the molecule has been studied, and dry etching resistance, developability, and substrate adhesion have been improved. However, it has encountered problems such as lack of substrate adhesion and lack of suitability for a standard developer due to extremely high solubility of the developer.

Further, J. Photopolym. Sci., Tech., Vol. 1
Although improvements have been made by copolymerizing alicyclic hydrocarbon monomers having an alcoholic hydroxyl group as described in U.S. Pat. No. 5,561 (1997), they have not yet reached a satisfactory level. Report of introduction of hydroxyl group into norbornene polymer main chain from the viewpoint of imparting substrate adhesion (J. Photopoly
m.Sci., Tech., Vol.10,529 (1997), J.Photopolym.Sci., Te
ch., Vol. 10, 521 (1997)), but satisfactory results were not obtained in both developability and substrate adhesion. Apart from these basic resist properties, when a resin having an alicyclic ring structure in the main chain is used for the resist, the film thickness dependency may be deteriorated in some cases. The film thickness dependency means that the resolving power is significantly deteriorated at a certain specific film thickness, and the shape of the resist pattern is deteriorated. As described above, while having high transparency to deep ultraviolet rays of ArF excimer laser light, having high dry etching resistance, being uniformly dissolved in an alkali developing solution, and having excellent adhesion to a substrate,
Moreover, a photosensitive composition having good film thickness dependency has not been obtained yet.

[0010]

SUMMARY OF THE INVENTION The object of the present invention has been made in view of the above problems, and has a high sensitivity to deep ultraviolet rays, particularly ArF excimer laser light.
An object of the present invention is to provide an excellent positive photosensitive composition that has excellent resolution and resist profile, has sufficient dry etching resistance, and can form a resist pattern that does not peel off from a substrate.

[0011]

Means for Solving the Problems The present inventors have conducted intensive studies on the constituent materials of a positive type chemically amplified resist composition, and as a result, have found that a resin containing a polymer containing a specific structure as a structural unit and a photoacid generator The present inventors have found that the object can be achieved by the combination of agents, and have reached the present invention. That is, the present invention is achieved by the following configurations. (1) (A) a compound that generates an acid upon irradiation with actinic rays or radiation, and (B) a divalent polycyclic alicyclic unit represented by the following general formula (I) or (II) A positive photosensitive composition comprising a resin having a polymer in the main chain of the polymer.

[0012]

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(In the above formula (I) or (II), R _{1 to} R ₄ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a cyclic alkyl group or an alkoxy group, an acid group capable of decomposing by the action of representing, or -Z-COOR _5,. the and at least two members out of _{R 1 ~R 4, -Z-C} (= O) -Y-C
A ring may be formed by forming a divalent linking group represented by (＝ O) —. R ₅ represents a hydrogen atom or an alkyl group, and Z represents a single bond or a —CH ₂ — group. R ₇ ,
R ₈ each independently represents a hydrogen atom or a methyl group. Y represents an oxygen atom, a sulfur atom or a —N (R ₆ ) — group, and R ₆ represents a hydrogen atom, an alkyl group, an alkoxy group, a group decomposed by the action of an acid, or a —Z-COOR ₅ group. . (2) The positive photosensitive composition as described in (1) above, wherein the resin has a group that is decomposed by the action of an acid. (3) It further has a group that can be decomposed by the action of an acid, and the alkali solubility is increased by the action of an acid.
The positive photosensitive composition as described in the above item (1), comprising a low-molecular acid-decomposable dissolution inhibiting compound having a molecular weight of 00 or less. (4) The positive photosensitive composition as described in any one of the above items (1) to (3), wherein far-ultraviolet light having a wavelength of 220 nm or less is used as an exposure light source.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the compounds used in the present invention will be described in detail. First, the resin of one component (B) of the present invention will be described. In the general formula (I), the group (also referred to as an acid-decomposable group) decomposed by the action of an acid in R ₁ , R ₂ , R ₃ , R ₄ , and R ₆ is-(CH
_{2) n-COORa} group or - (CH _{2) n} -OCO
Rb group. Here, Ra represents a hydrocarbon group having 2 to 20 carbon atoms, and examples of the hydrocarbon group include a t-butyl group, a norbornyl group, and a cyclodecanyl group. Rb represents an alkoxyethyl group such as a tetrahydrofuranyl group, a tetrahydropyranyl group, an ethoxyethyl group, an isopropylethyl group, a lactone group, or a cyclohexyloxyethyl group. n represents 0 or 1.
The alkyl group for R ₁ , R ₂ , R ₃ , and R ₄ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group,
Isopropyl group, n-butyl group, isobutyl group, sec
-Butyl group and t-butyl group.

The cyclic alkyl group for R ₁ , R ₂ , R ₃ , and R ₄ includes cyclopropyl, cyclopentyl, cyclohexyl, adamantyl, 2-methyl-2-adamantyl, norbornyl, boronyl, and isobornyl. Group, tricyclodecanyl group, dicyclopentenyl group, nobornane epoxy group, menthyl group, isomenthyl group, neomenthyl group, neomenthyl group, tetracyclododecanyl group and the like. Examples of the alkoxy group in R ₁ , R ₂ , R ₃ , R ₄ , and R ₆ include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

Further substituents in the above alkyl group, cyclic alkyl group and alkoxy group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group and an acyloxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group, examples of the acyl group include a formyl group and an acetyl group, and examples of the acyloxy group include an acetoxy group. Respectively. The alkyl group for R ₅ and R ₆ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group. Group, sec-butyl group and t-butyl group. As Y, an oxygen atom is preferable.

The resin in the present invention has the following general formula (II)
Ring-opening polymerization of the norbornene derivative, norbornadiene derivative and cyclic olefin represented by I) or (IV) to obtain a polymer represented by the following general formula (V) or (VI), and then the polymer Is obtained by hydrogenation of
In the case of an acid anhydride derivative, after ring-opening polymerization and hydrogenation, the acid anhydride may be ring-opened by modifying the alkali-treated product obtained by treatment with an alkali compound as necessary with an acid. Alternatively, the ring-opened acid anhydride may be further modified.

[0018]

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(In the general formulas (III) to (VI),
R ₁ , R ₂ , R ₃ , R ₄ , R ₇ , R ₈ , Z, and Y are the same as defined in the general formulas (I) and (II). In the present invention, the general formula (II) used as a starting material
The monomers represented by I) or (IV) include diene compounds such as cyclopentadiene and dicyclopentadiene and a vinyl compound containing a carboxyl group, a vinyl compound containing a carboxylic anhydride group, and N-substituted compounds. Or an unsubstituted cyclic imide compound or the like by a Diels-Alder reaction (HL Holmes, Organic Reactions, Vol. 4, p60
173 (1948)).

Examples of the vinyl compound containing a carboxyl group include one or more addition-polymerizable unsaturated bonds selected from acrylic acid, methacrylic acid, acrylic esters, methacrylic esters, crotonic esters and the like.
And specifically, for example, an alkyl acrylate having 1 to 8 carbon atoms, methyl acrylate,
Ethyl acrylate, propyl acrylate, t-acrylate
Butyl, amyl acrylate, cyclohexyl acrylate, 2-hydroxyethyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, t-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, adamantyl methacrylate, methacryl 2-hydroxyethyl acid,
Phenyl methacrylate, naphthyl methacrylate, tricyclodecanyl acrylate, tricyclodecyl acrylate, tetrahydropyranyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, methoxypropyl methacrylate, cyclohexylethyl methacrylate, adamantyl methacrylate Oxyethoxyethyl, adamantylcarbonyl oxyethoxyethyl methacrylate, 1-paramenthyl methacrylate, 3-oxocyclohexyl methacrylate, menthyl methacrylate, methyl crotonate and the like can be mentioned.

Examples of the vinyl compound containing a carboxylic acid anhydride group include maleic anhydride, itaconic anhydride, citraconic anhydride, α-methylglutaconic anhydride and the like. Examples of the N-substituted or unsubstituted imide compounds include N-substituted phthalimides, and the vinyl compounds containing a diene such as cyclopentadiene and dicyclopentadiene and a carboxylic acid anhydride group.
After the Diels-Alder reaction, a primary amine compound is reacted to obtain an amic acid, which can be easily obtained by imidation.

The ring-opening (co) polymerization of the norbornene derivative, norbornadiene derivative and cyclic olefin represented by the general formula (III) or (IV) is carried out in an organic solvent or a non-organic solvent in the presence of a metathesis catalyst. By ring-opening polymerization. Ring opening (co) polymerization is described, for example, in W.
L. Truett et al .; J. Am. Chem. Soc., 82, 2337 (1960) and A. Pacrea
u; Macromol.Chem., 188, 2585 (1987) and JP-A-51-318.
No. 00, JP-A-1-197460, JP-A-2-42094 and the like can be easily polymerized. The metathesis catalyst used herein is, for example, edited by The Society of Polymer Science, Japan: Synthesis and Reaction of Polymers (1), Kyoritsu Shuppan, p375-381 (1992) and JP-A-49-779.
No. 99, specifically, a catalyst system comprising a halogen compound of a transition metal such as tungsten and / or molybdenum and an organoaluminum compound or a combination thereof with a third component is used.

Specific examples of the above-mentioned tungsten and molybdenum compounds include molybdenum pentachloride, tungsten hexachloride and tungsten oxytetrachloride, and examples of the organic aluminum compounds include triethylaluminum, triisobutylaluminum, trihexylaluminum, and diethylaluminum monochloride. Ride, di-n-butylaluminum monochloride, ethylaluminum sesquichloride, diethylaluminum monobutoxide and triethylaluminum
Water (molar ratio 1: 0: 5).

In carrying out the ring-opening polymerization, the use ratio of the organoaluminum compound to 1 mol of the above-mentioned tungsten or molybdenum compound is preferably 0.5 mol or more. As a catalyst of the third component used for the purpose of improving polymerization activity and the like, water, hydrogen peroxide, an oxygen-containing organic compound, a nitrogen-containing organic compound, a halogen-containing organic compound,
Examples thereof include a phosphorus-containing organic compound, a sulfur-containing organic compound, and a metal-containing organic compound, which are used together in a proportion of 5 mol or less based on 1 mol of a tungsten or molybdenum compound. The use ratio of the catalyst to the monomer depends on the kind thereof, but is usually used in a ratio of 0.1 to 20 mol per 100 mol of the monomer.

The polymerization temperature in the ring-opening (co) polymerization is -40.
C. to + 150.degree. C., preferably in an inert gas atmosphere. Specific examples of the solvent used include aliphatic hydrocarbons such as pentane, hexane, heptane and octane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, and aromatic hydrocarbons such as benzene, toluene and xylene. , Methylene chloride, 1,1-dichloroethane,
1,2-dichloroethylene, 1-chloropropane, 1-
Chlorobutane, 1-chloropentane, chlorobenzene,
Examples include halogenated hydrocarbons such as bromobenzene, o-dichlorobenzene, and m-dichlorobenzene, and ether compounds such as diethyl ether and tetrahydrofuran.

The resin used in the present invention is obtained by hydrogenating the resin represented by the above general formula (V) or (VI) obtained by such ring-opening (co) polymerization. As the catalyst used in the hydrogenation reaction, those used in the usual hydrogenation reaction of olefinic compounds can be used. For example, examples of the heterogeneous catalyst include a solid catalyst in which a noble metal catalyst such as palladium, platinum, nickel, ruthenium, and rhodium is supported on a carrier such as carbon, silica, alumina, and titania. Examples of homogeneous catalysts include nickel / triethylaluminum naphthenate, nickel acetylacetonate / triethylaluminum, cobalt / n-butyllithium octoate, titanocene dichloride / diethylaluminum monochloride, rhodium acetate, and chlorotris (triphenylphosphine) rhodium. And rhodium catalysts.

Among these catalysts, it is advantageous to use a heterogeneous catalyst since the reaction activity is higher, the catalyst can be easily removed after the reaction, and the resulting polymer does not color. The hydrogenation reaction is carried out at normal pressure to 300 atm, preferably 3 to 20 atm.
Under a hydrogen gas atmosphere of 0 atm, the temperature is 0 to 200.
C, preferably in the range of 20 to 180C. The hydrogenation rate is usually at least 50%, preferably at least 70%, more preferably at least 80%. If the hydrogenation rate is less than 50%, the thermal stability and the aging stability of the resist are undesirably deteriorated.

In the following, examples of the repeating unit of the (co) polymer used in the present invention obtained as described above include the following (a) to (p), but the present invention is limited by these examples. It is not something to be done.

[0029]

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[0030]

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After the reaction for a predetermined time, it is preferable to carry out a purification treatment such as distillation under reduced pressure for the purpose of separating the obtained resin of the present invention from unreacted monomer components, solvents and the like. The thus obtained resin of the present invention is measured for its retention time by gel permeation chromatography equipped with a refractive index detector, using polystyrene having a known molecular weight as a control, and the weight average molecular weight is determined.

In the resin of the present invention, the content of the repeating unit represented by the general formula (I) or (II) is preferably at least 10 mol%, more preferably at least 20 mol%, of the repeating units of all monomers. The content is more preferably 30 mol% or more. When the resin of the present invention contains an acid-decomposable group, the content of the acid-decomposable group-containing repeating unit is preferably from 10 to 90 mol% in the repeating units of all the monomers,
More preferably 15 to 85 mol%, even more preferably 20 to
~ 80 mol%.

For the purpose of improving the performance of the resin of the present invention,
Other ring-opening polymerizable monomers may be copolymerized within a range that does not significantly impair the transparency of 220 nm or less and the dry etching resistance of the resin. Examples of these other ring-opening polymerizable monomers include the following cyclic olefins, for example, cyclopentene, cycloheptene,
Monocyclic olefinic compounds such as cyclooctene and cyclododecene, 1,5-cyclooctadiene, cyclopentadiene, 1,5,9-cyclododecatriene, 1-
Chloro-1,5-cyclooctadiene, dicyclopentadiene, ethylidene norbornene,

Also, methyl 5-norbornene-2-carboxylate, dimethyl 5-norbornene 2,3-dicarboxylate, t-butyl 5-norbornene-2-carboxylate,
-Norbornene 2,3-dicarboxylic acid, 5-norbornene-2-nitrile, 5-norbornene-2-carboxylic acid amide, N, N-dimethyl-5-norbornene 2-carboxylic acid amide, 5-norbornene 2,3-dicarboxylic acid Acid imide, Nt-butyl-5-norbornene 2,3-dicarboxylic imide, 5-chloro-2-norbornene,
-Norbornene-2,3-dicarboxylic anhydride (hymic anhydride), 2-methyl-5-norbornene-2,3
-Dicarboxylic anhydride, 1,4,5,8-dimethano 1,
2,3,4,4a, 5,8-octahydronaphthalene 2,3 dicarboxylic anhydride, norbornadiene, 5-carboxycyclohexylbicyclo [2,2,1] -2-
Heptene, 5-carboxymethylbicyclo [2,2,
1] -2-heptene, 5-carboxylbicyclo [2,
2,1] -2-heptene,

Further, 5-carboxy t-butylbisic
B [2,2,1] -2-heptene, 5-methyl-5-ca
Ruboxyl t-butylbicyclo [2,2,1] -2-hep
Ten, 8-methyl-8-carboxymethyltetracyclo
[4,4,0,1^2,5, 1^{7, Ten}] -3-dodecene, 8-
Carboxytetracyclo [4,4,0,1^2,5, 1
^7,10] -3-dodecene, 8-methyl-8-carboxyt
-Butyltetracyclo [4,4,0,1^2,5, 1^7,10]
-3-Dodecene, 8-carboxyadamantyl-2'-
Bicyclo [2,2,1] -2-heptene, 8-methyl-
8-carboxypentacyclo [6.6.1.1^3,6. 0
^2,7. 0^9,14] -4'-tetracyclo [4,4,0,1
^2,5, 1^7,10] -Carbon-carbon double bonds such as 3-dodecene
Non-conjugated cyclic polyene compounds having two or more
I can do it. Corresponds to the ring-opening polymerizable monomer as described above
As the content of the repeating unit in the resin, the total repeating unit
Is preferably 60 mol% or less, more preferably
Is at most 50 mol%, more preferably at most 40 mol%.
You.

The weight average molecular weight of the resin used in the present invention is preferably in the range of 1500 to 100,000, more preferably in the range of 2000 to 70000, and particularly preferably in the range of 3000 to 50,000. When the molecular weight is less than 1500, the dry etching resistance, heat resistance, and adhesion to the substrate are insufficient, and the molecular weight is 1,000.
If it exceeds 00, the resist sensitivity is undesirably lowered. The degree of dispersion (Mw / Mn) is preferably 1.0 to
6.0, more preferably 1.0 to 4.0, and the smaller the smaller, the better the heat resistance and image performance (resist profile, defocus latitude, etc.).

In the present invention, the photosensitive composition of the above resin
(Excluding solvent)
It is 0 to 99.7% by weight, preferably 70 to 99% by weight. In the present invention, in addition to the resin in the present invention, if necessary, another polymer can be used in combination, in this case, a preferred range of other polymers used in combination,
The amount is at most 70 parts by weight, particularly preferably at most 50 parts by weight, per 100 parts by weight of the resin in the present invention.

When the resin of the present invention contains an acid-decomposable group, the alkali solubility increases due to the action of an acid, and the resin may or may not contain a low-molecular acid-decomposable dissolution inhibiting compound having a molecular weight of 1,000 or less. Preferably, when the resin does not contain an acid-decomposable group, the resin preferably contains the low-molecular acid-decomposable dissolution inhibiting compound. That is, in order to increase the ratio of dissolution rate to alkali in the unexposed area and the exposed area and to obtain high resolution, it is effective to add a compound which increases the alkali solubility by the action of an acid.

Next, the component (A) in the positive photosensitive composition of the present invention, and a compound capable of decomposing upon irradiation with actinic rays or radiation to generate an acid (also referred to as a photoacid generator) will be described. 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, Photochromic or ultraviolet light,
A known photoacid generator and a mixture thereof are appropriately selected and used for a microphotoresist which generates acid by far ultraviolet rays, KrF excimer laser light, ArF excimer laser light, electron beam, X-ray, molecular beam or ion beam. can do.

Of these, preferred for use in the present invention are photoacid generators which generate an acid with light having a wavelength in the range of 220 nm or less. Any photoacid generator may be used as long as the mixture is sufficiently soluble in an organic solvent. Further, they may be used alone or as a mixture of two or more kinds, or may be used in combination with an appropriate sensitizer. Examples of photoacid generators that can be used include, for example, J. Org. Chem. Vol. 43, N0.15, 3055
(1978) and other onium salts (sulfonium salt, iodonium salt, phosphonium salt, diazonium salt, ammonium salt) described in Japanese Patent Application No. 9-279071.

Specific examples of the onium salt include diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, diphenyliodonium hexafluoroantimonate, triphenyliodonium hexafluoroantimonate and triphenyliodonium hexafluoroantimonate. Sulfonium naphthalene sulfonate, triphenylsulfonyumcamphorsulfonium, (4-methoxyphenyl) phenyliodonium trifluoromethanesulfonate, bis (t-butylphenyl) iodonium trifluoromethanesulfonate and the like can be mentioned.

Further, JP-A-3-103854, JP-A-3-103856
Diazodisulfones and diazoketosulfones described in JP-A-4-210960, JP-A-64-18143, JP-A-2-24
Iminosulfonates described in 5756, JP-A-2-71270
The disulfones described in (1) can also be suitably used.
Further, USP 3849137, JP-A-63-26653, JP-A-62-692
No. 63, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, etc. Alternatively, a compound introduced into a side chain can also be used.
No. 6, JP-A-7-28237, JP-A-7-92675, JP-A 8-
No. 27120, aliphatic alkylsulfonium salts having a 2-oxocyclohexyl group and N-hydroxysuccinimide sulfonates, and furthermore, J. Photopolym.Sc
The sulfonium salts described in i., Tech., Vol. 7, No. 3, 423 (1994) can also be suitably used, and these compounds can be used alone or in combination of two or more.

The amount of the compound capable of decomposing upon irradiation with actinic rays or radiation to generate an acid is usually 0.1 to 10% based on the total weight of the photosensitive composition (excluding the coating solvent).
The range is preferably from 001 to 40% by weight, more preferably from 0.01 to 20% by weight, even more preferably from 0.1 to 5% by weight. When the amount of the photoacid generator is less than 0.001% by weight, the sensitivity is low, and when the amount is more than 40% by weight, the light absorption is too high,
It is not preferable because the profile is deteriorated and the process (especially baking) margin is narrowed.

The positive photosensitive composition of the present invention may contain, if necessary, an acid-decomposable dissolution inhibiting compound, an organic basic compound, and a compound capable of promoting the solubility in a developing solution. . As the low-molecular acid-decomposable dissolution-inhibiting compound used in the present invention, a compound that does not decrease the transmittance to light having a wavelength of 220 nm or less, the dry etching resistance, and the heat resistance is preferable. For example, Proc.SPIE,
2724,355 (1996) and JP-A-8-15865, US5310619, US
As described in No. 5372912, derivatives of cholic acid containing acid-decomposable groups, dehydrocholic acid derivatives, deoxycholic acid derivatives, lithocholic acid derivatives, ursocholic acid derivatives, and abietic acid derivatives containing acid-decomposable groups Such alicyclic compounds can also be preferably used.

The low-molecular acid-decomposable dissolution-inhibiting compounds described in JP-A-6-51519 can also be used in an addition range which does not deteriorate the transmittance to light having a wavelength of 220 nm, and 1,2-naphthoquinone Diazite compounds can also be used. In the present invention, when the low-molecular acid-decomposable dissolution inhibiting compound is used, its addition amount is usually in the range of 1 to 50% by weight, based on the total weight of the photosensitive composition (excluding the coating solvent). Preferably it is in the range of 3 to 40% by weight, more preferably 5 to 30% by weight.

The positive photosensitive composition of the present invention may contain, if necessary, an organic basic compound and a compound which promotes solubility in a developer. Preferred organic basic compounds that can be used in the present invention include compounds having a higher basicity than phenol, and among them, nitrogen-containing basic compounds are preferable. The organic basic compound is added mainly for the purpose of improving the stability with time and the adhesion property of the acid scavenger and the resist.

For example, JP-A-63-149640, JP-A-5-24
No. 9662, JP-A-6-242605, JP-A-6-242606, JP
Basic compounds described in JP-A-6-266100, JP-A-7-120929, JP-A-9-274312 and JP-A-7-508840 are mentioned, and those which do not vaporize or sublime are preferably used. Among these, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [2.2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, N-methylformamide, piperidine, hexamethylenetetramine and imidazoles are particularly preferably used.

Also, JP-A-6-242606, JP-A-6-242605
, A basic ammonium salt or a sulfonium salt described in JP-A-8-110635, or an internal salt such as betaine can also be used. Among these, pyridinium p-
Toluenesulfonate, 2,4,6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate, tetrabutylammonium lactate and the like are particularly preferably used. 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 usually 0.00.0 parts by weight per 100 parts by weight of the photosensitive composition (excluding the solvent).
The amount is from 0.01 to 10 parts by weight, preferably from 0.01 to 5 parts by weight. If the amount is less than 0.001 part by weight, the effect of adding the nitrogen-containing basic compound cannot be obtained. On the other hand, if it exceeds 10 parts by weight, the sensitivity tends to decrease and the developability of the non-exposed area tends to be significantly deteriorated.

Examples of the compound capable of accelerating dissolution in a developer which can be used in the present invention include compounds having two or more phenolic hydroxyl groups described in JP-A-3-206458,
Naphthols such as naphthol or JP-A-3-179355
No., JP-A-5-181279, JP-A-9-6001, JP-A-9-2743
No. 18, US5374500, DE4214363, compounds having one or more carboxyl groups, carboxylic anhydrides,
Low molecular weight compounds having a molecular weight of 1000 or less, such as sulfonamide compounds and sulfonylimide compounds described in 9-279071, can be mentioned.

Among these, a dissolution accelerating compound which does not deteriorate the transmittance for light having a wavelength of 220 nm is preferable.
For example, steroids, norsteroids, and terpenoids are preferable, and in particular, adamantanecarboxylic acid, cholic acid, norcholanic acid, abietic acid, and agatendicarboxylic acid are mentioned. The addition amount of the dissolution accelerating compound to the developer in the composition is the total weight of the composition (solid content)
30 parts by weight or less, more preferably 2 parts by weight
0 parts by weight or less. The positive photosensitive composition of the present invention may further contain, if necessary, an antihalation agent, a plasticizer, a surfactant, a photosensitizer, an adhesion aid, a crosslinking agent, a photobase generator, and the like. .

As a suitable antihalation agent, a compound which efficiently absorbs the irradiated radiation is preferable, and substituted benzenes such as fluorene, 9-fluorenone and benzophenone, anthracene, anthracene-9-methanol, and anthracene-9-carboxy. Examples thereof include polycyclic aromatic compounds such as ethyl, phenanthrene, perylene, and azylene. Of these, polycyclic aromatic compounds are particularly preferable. These antihalation agents exhibit the effect of improving the standing wave by reducing the reflected light from the substrate and reducing the influence of multiple reflection in the resist film.

In order to improve the rate of acid generation upon exposure, the following photosensitizers can be added. Suitable photosensitizers include, specifically, benzophenone, P
-P 'tetramethyldiaminobenzophenone, 2-chlorothioxanthone, anthrone, 9-ethoxyanthracene, pyrene, phenothiazine, benzyl, benzoflavin, acetophenone, phenanthrene, benzoquinone, anthraquinone, 1,2-naphthoquinone, and the like. It is not limited to these. These photosensitizers can also be used as the antihalation agent.

To the photosensitive composition of the present invention, the following surfactants can be added for the purpose of improving coating properties and developing properties. Examples of such surfactants include:
For example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, polyoxyethylene sorbitan monostearate, sorbitan monolaurate, etc. Nonionic surfactant, F-Top EF
301, EF303, (Shin-Akita Chemical Co., Ltd.), Florard FC430,
431 (manufactured by Sumitomo 3M Limited), Mega Fuck F171, F17
3 (Dainippon Ink Co., Ltd.), Surflon S-382, SC101, 10
Fluorosurfactants such as 2,103,104,105,106 (manufactured by Asahi Glass Co., Ltd.) and polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.).

The amount of these surfactants is usually 2 parts by weight or less, preferably 1 part by weight or less, per 100 parts by weight of the solids in the composition of the present invention. These surfactants can be added alone or in combination of two or more. The positive photosensitive composition of the present invention may further contain a plasticizer, an adhesion aid, a crosslinking agent, a photobase generator, an antifoaming agent, and the like, if necessary.

The photosensitive composition of the present invention is usually dissolved, for example, in a solvent having a pore diameter of 0.05 μm
It is prepared as a solution by filtering with a filter of about 0.2 μm. As the solvent used herein, for example, ethylene glycol monoethyl ether acetate, cyclohexanone, 2-heptanone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether acetate, Methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl β-methoxyisobutyrate, ethyl butyrate, propyl butyrate, methyl isobutyl ketone, ethyl acetate, isoamyl acetate, ethyl lactate,

Further, toluene, xylene, cyclohexyl acetate, diacetone alcohol, N-methylpyrrolidone, N, N-dimethylformamide, γ-butyrolactone, N, N-dimethylacetamide and the like can be mentioned.
These solvents are used alone or in a mixture of a plurality.
The choice of the solvent is important because it affects the solubility in the composition, the applicability to the substrate, the storage stability, and the like, and the moisture contained in the solvent also affects these performances. Further, the photosensitive composition of the present invention contains 10% of metal impurities such as metal and impurity components such as chlorion.
It is preferable to reduce it to 0 ppb or less. The presence of these impurities is not preferable because it causes operation failure, defects, and a decrease in yield in manufacturing a semiconductor device.

The photosensitive composition prepared by satisfying the above-mentioned various conditions is coated on a substrate by a suitable coating means such as a spinner or a coater, and then prebaked (pre-exposure baking) and passed through a predetermined mask to reach a thickness of 220 nm or less. A good resist pattern can be obtained by exposing with exposure light having a wavelength of, performing PEB (bake after exposure), and developing. The substrate used here may be any substrate usually used in semiconductor devices and other manufacturing equipment,
For example, a silicon substrate, a glass substrate, a non-magnetic ceramic substrate and the like can be mentioned.

Further, on these substrates, if necessary, additional layers such as a silicon oxide layer, a metal layer for wiring,
An interlayer insulating film, a magnetic film, an antireflection film layer, and the like may be present, and various wirings, circuits, and the like may be formed. Furthermore, these substrates may be subjected to a hydrophobic treatment according to a conventional method in order to enhance the adhesion of the resist film. Suitable hydrophobizing agents include, for example, 1,1,1,
3,3,3-hexamethyldisilazane (HMDS) and the like. The thickness of the resist applied on the substrate is preferably in the range of about 0.1 μm to 10 μm, and in the case of ArF exposure, a thickness of 0.1 μm to 1.5 μm is recommended.

The resist film applied on the substrate is about 60
It is preferred to pre-bake at a temperature of １６０160 ° C. for about 30 to 300 seconds. If the pre-baking temperature is low and the time is short, the amount of residual solvent in the resist film becomes relatively large, and adverse effects such as deterioration of adhesion are caused, which is not preferable. On the other hand, if the prebaking temperature is high and the time is long, adverse effects such as decomposition of components such as the binder and the photoacid generator of the photosensitive composition occur, which is not preferable.

[0061] As apparatus for exposing a resist film after prebaking, a commercially available ultraviolet exposure apparatus, X-ray exposure apparatus, an electron beam exposure apparatus, KrF excimer exposure apparatus, ArF excimer exposure system, F ₂ excimer exposure device and the like are used Particularly, in the present invention, an apparatus using an ArF excimer laser as an exposure light source is preferable. The baking treatment after the exposure is performed for the purpose of causing elimination of a protecting group using an acid as a catalyst, for eliminating a standing wave, or for diffusing an acid generator or the like into a film. The post-exposure bake can be performed in the same manner as the pre-bake. For example, the baking temperature is about 60-160C, preferably about 90-150C.

As the developer for the photosensitive composition of the present invention,
Sodium hydroxide, potassium hydroxide, sodium carbonate,
Inorganic alkalis such as sodium silicate and aqueous ammonia,
Primary amines such as ethylamine and n-propylamine;
Secondary amines such as diethylamine and di-n-butylamine; and tertiary amines such as triethylamine and methyldiethylamine.
Amines, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, trimethylhydroxyethyl Quaternary ammonium salts such as ammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo- [5,
4,0] -7-undecene, 1,5-diazabicyclo-
An aqueous alkaline solution such as a cyclic amine such as [4,3,0] -5-nonane can be used.

Further, an appropriate amount of a hydrophilic organic solvent such as alcohols or ketones, a nonionic or anionic surfactant, a cationic surfactant or an antifoaming agent may be added to the alkaline aqueous solution. Can be used. These additives may be used to improve the performance of the resist, increase the adhesion to the substrate, reduce the amount of developer used, or reduce defects caused by bubbles during development. Added to the aqueous solution.

[0064]

The present invention will be described in more detail with reference to examples including synthesis examples, but the present invention is not limited thereto. Synthesis Example 1 Synthesis of Monomer a: 4,5-Cyclohexenedicarboxylic anhydride and dicyclopentadiene were converted to ordinary Di
els-Alder reaction ("Organic Reactions" by HL Holmes
4, p60-173 (1948), published by John Wiley and Sons), and processed into 5,8-methano-
1,2,3,4,4a, 5,8,8a-octahydronaphthalene-1,2-dicarboxylic anhydride was synthesized.

[0065]

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Synthesis Example 2 Synthesis of Monomer b: 4-methyl-4,5-cyclohexenedicarboxylic anhydride and dicyclopentadiene were reacted in the same manner as in Synthesis Example 1 to give 5,8-methano-1- having the following structure: Methyl-1,2,3,4,4
a, 5,8,8a-Octahydronaphthalene-2,3-
Dicarboxylic anhydride was synthesized.

[0067]

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Synthesis Example 3 Synthesis of Monomer c: (4-carboxy-5-cyclohexenyl) acetic anhydride and dicyclopentadiene were reacted in the same manner as in Synthesis Example 1 to give 2-oxa-1,3-having the following structure: Dioxo-1,2,3,4,4
a, 5,8,8a, 9,9a, 10,10a-dodecahydroanthracene was synthesized.

[0069]

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Synthesis Example 4 Synthesis of Monomer d: Cyclopentadiene and 4-methyl-4- (t-butoxycarbonyl) -cyclohexene were reacted in the same manner as in Synthesis Example 1,
A monomer d having the following structure was synthesized.

[0071]

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Synthesis Example 5 Synthesis of Monomer e: Cyclopentadiene and 4-methyl-4- (tetrahydropyranylcarbonyl) -cyclohexene were reacted in the same manner as in Synthesis Example 1 to synthesize a monomer e having the following structure.

[0073]

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Synthesis Example 6 Synthesis of Monomer f N-hydroxy-5,8-methano-1,2,3,4,4
a, 8,8a-Octahydronaphthalene-2,3-dicarboximide and dicyclopentadiene are converted to ordinary Diels-
Alder reaction (edited by John D. Roberts; Organic Syntheses No. 41)
Vol., Pp. 93-95 (1961), published by John Wiley and Sons) to synthesize a monomer f having the following structure.

[0075]

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Synthesis Example 7 Synthesis of Monomer g According to the method of Cristol et al. (J. Am. Chem. Soc., 81, 655 (1959)), dicyclopentadiene and 2-carbobutoxycyclopentene were treated by the Diels-Alder reaction. 1,2-Dihydro-endo-dicyclopentadiene (monomer g) having the following structure was synthesized.

[0077]

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Synthesis Example 8 Synthesis of Copolymerizable Monomer h Dicyclopentadiene and t-butyl methacrylate were reacted in the same manner as in Synthesis Example 1 to give 8-methyl-8-
Carboxy tert-butyl tetracyclo [4.4.0.1
^2,5 . 1 ^7,10 ] -3-dodecene was synthesized.

[0079]

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Synthesis Example 9 Synthesis of acid-decomposable low molecular weight compound a A mixture of 112.7 g (0.3 mol) of cholic acid and 120 ml of thionyl chloride was refluxed for 1 hour. Excess thionyl chloride was removed, the obtained solid was dissolved in 150 ml of tetrahydrofuran, 40 g (0.35 mol) of potassium tert-bucitoxide was gradually added, the reaction mixture was refluxed for 6 hours, cooled, and then cooled in water. Poured into. The obtained solid was collected by filtration, washed with water, dewatered, and dried under reduced pressure. The purified product was recrystallized from n-hexane to obtain tert-butyl cholate of the following formula in a yield of 70%.

[0081]

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Synthesis Example 10 (Synthesis of Polymer A of the Present Invention) In a 1 L autoclave purged with nitrogen, 150 g of the monomer a synthesized in Synthesis Example 1 above, 600 ml of 1,2-dichloroethane, 0.02 mol per 100 ml 23.3 ml of a 1,2-dichloroethane solution containing tungsten hexachloride and 0.06 mol of acetaldehyde diethyl acetal (4.6 mmol of tungsten hexachloride)
After that, the reaction system was heated to 60 ° C. To this reaction system, 27.9 ml of a toluene solution of diethyl aluminum chloride (concentration: 0.1 mol / l) (27.6 mmol of diethyl aluminum chloride in the solution) was further added, and the temperature was maintained at 60 ° C. while stirring. The polymerization was carried out by heating for 2 hours, and the polymerization was further continued at room temperature for 18 hours.

[0083] was filtered off polymer obtained in the above polymerization reaction, 1L
After washing with 1,2-dichloroethane at 50 ° C.
After drying under reduced pressure for 134 hours, 134 g of a polymer 1b (the following formula) was obtained. 82 g of this polymer 1b was placed in a 1 L flask,
800 g of distilled water containing 40 g of sodium hydroxide was added, and the mixture was reacted at room temperature with stirring for about 4 hours. After completion of the reaction, water was distilled off from the reaction system under reduced pressure, and the product was dried at 60 ° C. under reduced pressure to obtain a sodium hydroxide-treated polymer 1c (the following formula). 11.3 g of this polymer 1c was added to 3
In a 00 ml flask, about 100 ml of distilled water was added, and 120 ml of 1N hydrochloric acid was added with stirring. 3
After stirring at 0 ° C. for 48 hours, the resulting polymer was separated by filtration, washed well with distilled water, and dried under reduced pressure at 50 ° C. for 24 hours to obtain a modified hydrochloric acid polymer 1d (the following formula). . The hydrochloric acid modified polymer 1d obtained above and thionyl chloride 36m
After the mixture was refluxed for 2 hours, excess thionyl chloride was removed and the resulting solid was treated with tetrahydrofuran 5
0 ml, and add potassium-t-bucitoxide 1
2 g was gradually added, the mixture was refluxed for 6 hours, cooled, and then poured into water. The generated solid was separated by filtration, washed with water, and dried under reduced pressure. The resulting purified product was recrystallized from n-hexane, and 89% of the carboxyl groups were modified to COO (CH ₃ ) ₃ groups to obtain a polymer A (the following formula). The weight average molecular weight of this polymer A determined by gel permeation chromatography was 13,200, and the degree of dispersion was 3.9.

[0084]

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Synthesis Example 11 (Synthesis of Polymer B of the Present Invention) Polymer B of the present invention was synthesized in the same manner as in Synthesis Example 10 except that monomer a in Synthesis Example 10 was changed to monomer b. 91% of the carboxyl groups were replaced by COO (CH ₃ ) ₃ groups). The weight average molecular weight by gel permeation chromatography was 9,600, and the degree of dispersion was 3.3.
Met.

[0086]

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Synthesis Example 12 (Synthesis of Polymer C of the Present Invention) 70 parts by weight of the monomer a of Synthesis Example 10 and 30 parts by weight of the monomer c obtained in Synthesis Example 3 were charged.
Polymer C of the present invention (the following formula; 90% of carboxyl groups were substituted with COO (CH ₃ ) ₃ groups) was obtained. The weight average molecular weight by gel permeation chromatography was 8,200, and the degree of dispersion was 3.3.

[0088]

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Synthesis Example 13 (Synthesis of Copolymer D of the Present Invention) 85 parts by weight of monomer d obtained in Synthesis Example 4 and 15 parts by weight of monomer a obtained in Synthesis Example 1 were used as molecular weight regulators.
Using hexene with a catalyst consisting of tungsten hexachloride-p-aldehyde-triisobutylaluminum,
The reaction was carried out in 1,2-dichloroethane for 6 hours. After completion of the reaction, 50 parts by weight of the obtained copolymer was dissolved in 1000 parts by weight of THF, hydrogenated using 1 part by weight of a Pd / C hydrogenation catalyst, and the catalyst was filtered off. To precipitate a copolymer. It was dried at 60 ° C. under reduced pressure to obtain a copolymer D of the present invention (following formula). The weight average molecular weight by gel permeation chromatography is 6
At 200, the dispersity was 2.7.

[0090]

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Synthesis Example 14 (Synthesis of Copolymer E of the Present Invention) Synthesis was performed in the same manner as in Synthesis Example 13 except that monomer d was changed to monomer e and monomer a was changed to monomer f. An inventive copolymer E (following formula) was obtained. The weight average molecular weight by gel permeation chromatography was 8,800, and the degree of dispersion was 3.3.

[0092]

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Synthesis Example 15 (Synthesis of Polymer F of the Present Invention) In a dry box purged with nitrogen according to the literature (Kobayashi et al., Ring Opening Polymerization Method described in Kogaku Kagaku Magazine, Vol. 70, No. 3, (1967)) Then, take a predetermined amount of WCl ₆ into a polymerization test tube, add 1 ml of toluene thereto, and dilute 10 times the volume of AlEt ₃
Was added and the mixture was aged at 0 ° C. for 10 minutes. 3 mol / l of the monomer g synthesized in Synthesis Example 7
After adding to the catalyst system as a toluene solution of
For 1 hour. After the polymerization, the content was transferred to a methanol solution to which a small amount of phenyl-β-naphthylamine was added to precipitate the polymer. The polymer was further washed several times with methanol and dried. Thereafter, hydrogenation was carried out in the same manner as in Synthesis Example 14 to obtain a polymer F of the present invention (following formula). The weight average molecular weight by gel permeation chromatography was 3,600, and the dispersity was 2.5.

[0094]

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Synthesis Example 16 (Synthesis of Copolymer G of the Present Invention) 30 parts by weight of monomer b synthesized in Synthesis Example 2, 40 parts by weight of monomer d synthesized in Synthesis Example 4, and 40 parts by weight of Synthesis Example 8 Assuming that the synthesized monomer h is 30 parts by weight,
The copolymer was treated and polymerized in the same manner as in Synthesis Example 13 to obtain a copolymer G (the following formula) of the present invention. The weight average molecular weight by gel permeation chromatography was 7,700, and the degree of dispersion was 3.0.

[0096]

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Synthesis Example 17 (Synthesis of Polymer H for Comparison) EP0789 was obtained by hydrogenating a ring-opened polymer of a norbornene derivative described in Example 4 of JP-A-9-244247.
The compound was synthesized according to the method described in No. 278.

[0098]

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Synthesis Example 18 (Synthesis of Polymer I for Comparison) EP0789 was obtained by hydrogenating a ring-opened polymer of a norbornene derivative described in the first example of JP-A-9-244247 (the following formula).
The compound was synthesized according to the method described in No. 278.

[0100]

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Example 1-7-A (Measurement of Optical Density) Polymers A to G obtained in Synthesis Examples 10 to 16, acid-decomposable low molecular weight compound a obtained in Synthesis Example 9, onium salt and solvent Were mixed and dissolved at the ratios shown in Table 1. To this, 0.1% of triethylamine in solid content, fluorine surfactant F1
77P (manufactured by Dainippon Ink and Chemicals, Inc.)
m was added and dissolved to prepare a photosensitive composition. This was filtered through a 0.1 μm Teflon filter, and the filtrate obtained was uniformly coated on a quartz substrate using a spin coater, and heated and dried on a hot plate at 100 ° C. for 90 seconds to obtain a 1.00 μm A resist film was formed. The optical absorption of the obtained film with respect to ArF excimer laser light (193 nm) was measured with an ultraviolet spectrophotometer. The results are as shown in Table 2. The optical density at 193 nm of each resist was 0.5 or less, and the measured optical density of the resist using the resin of the present invention was the value obtained by the poly (hydroxystyrene) of Comparative Example 1. It was found to be smaller and had sufficient transparency to 193 nm light.

[0102]

[Table 1]

[0103]

[Table 2]

Example 1-7-B (Measurement of Dry Etching Resistance) The photosensitive compositions of the present invention of Examples 1 to 7 in Table 1 were filtered with a 0.1 μm Teflon filter. Each of the obtained filtrates was uniformly coated on a silicon substrate using a spin coater, and dried by heating on a hot plate at 100 ° C. for 90 seconds to form a 0.7 μm resist film. The resulting respective films manufactured by ULVAC reactive ion etching apparatus (CSE-1110) using, CF _4/0
The etching rate for ₂ (8/2) gases was measured.
Table 3 shows the results. The etching rate of the resist using the resin of the present invention was sufficiently smaller than that of poly (methyl methacrylate) of Comparative Example 2 described later, and it was revealed that the resist had sufficient dry etching resistance.

[0105]

[Table 3]

Example 8 (Evaluation of Image) The photosensitive compositions of the present invention of Examples 1 to 7 in Table 1 were filtered with a 0.1 μm Teflon filter. Using a spin coater, each of the obtained filtrates was uniformly applied onto a hexamethyldisilazane-treated silicon substrate, and dried by heating on a hot plate at 120 ° C. for 90 seconds to form a 0.5 μm resist film. Were respectively formed. Each of the resist films is exposed to ArF excimer laser light through a mask, and immediately after the exposure,
After heating on a hot plate at 0 ° C. for 90 seconds, the film was further developed with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and dried.

The pattern obtained here was observed with a scanning electron microscope, and the sensitivity, profile, critical resolution, and adhesion were examined. Table 4 shows the results. The sensitivity was represented by an exposure amount for reproducing a 0.30 μm mask pattern. The critical resolution was defined as the critical resolution at an exposure amount that reproduced a 0.30 μm mask pattern. Adhesion is 0.20μm
Were examined for the adhesion of 30 dot patterns, and the number of pattern peelings was determined. The results are summarized in Table 4. As is clear from Table 4, the resists using the polymer of the present invention were excellent in sensitivity and resolution, and all formed rectangular profiles. In addition, no peeling of the pattern was observed, and there was no problem in adhesion.

[0108]

[Table 4]

Comparative Example 1 A resist film was formed in the same manner as in Example 1 except that the polymer A in Example 1 was replaced with poly (hydroxystyrene) having a molecular weight of 8000. The optical absorption of the obtained film was measured by an ultraviolet spectrophotometer.
The optical density at 3 nm was 1.50 or more. Comparative Example 2 A resist film was formed in the same manner as in Example 2 except that the polymer A of Example 1 was replaced with a poly (methyl methacrylate) molecular weight of 12,000, and the etching rate was measured. The results are shown in Table 3 as 1250 ° / min. Met.

Comparative Example 3 Using the polymer H obtained in Synthesis Example 17, a resist was prepared in the same manner as in Example 1, and the performance was examined. As shown in Table 4, the sensitivity, resolution, and adhesion of the resist were inferior to those of Examples 1 to 7 containing the resin of the present invention. Comparative Example 4 A resist was prepared in the same manner as in Example 1 using the polymer I obtained in Synthesis Example 18, and the performance was examined. As shown in Table 4, the sensitivity, resolution, and adhesion of the resist were inferior to those of Examples 1 to 7 containing the resin of the present invention.

[0111]

As is apparent from the above description, the positive photosensitive composition using the resin of the present invention has high transparency especially to far ultraviolet light of 220 nm or less, and is resistant to dryness. Good etching properties. In particular, when an ArF excimer laser beam is used as an exposure light source, it exhibits high sensitivity, high resolution, a good pattern profile, and excellent adhesion to a substrate. Therefore, it can be effectively used for forming a fine pattern required for manufacturing a semiconductor device, and it is extremely large that it contributes to the technology in this kind of field.

Claims (4)

[Claims] 1. A compound which generates an acid upon irradiation with actinic rays or radiation, and (B) a divalent polycyclic alicyclic ring represented by the following formula (I) or (II): A positive photosensitive composition comprising a resin having a formula unit in the main chain of the polymer. Embedded image In the above general formula (I) or general formula (II), R _{1 to} R ₄ are each independently decomposed by the action of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a cyclic alkyl group or an alkoxy group, and an acid. Group, or-
Representing the Z-COOR _5. Further, at least two of R _{1 to} R ₄ are bonded to form -ZC (= O) -YC (= O)
A divalent linking group represented by-may be formed to form a ring. R ₅ represents a hydrogen atom or an alkyl group, and Z represents a single bond or a —CH ₂ — group. R ₇ and R ₈ each independently represent a hydrogen atom or a methyl group. Y represents an oxygen atom, a sulfur atom or a —N (R ₆ ) — group, and R ₆ represents a hydrogen atom, an alkyl group, an alkoxy group, a group decomposed by the action of an acid, or a —Z-COOR ₅ group. . 2. The positive photosensitive composition according to claim 1, wherein the resin has a group that is decomposed by the action of an acid. 3. A low molecular weight acid-decomposable dissolution inhibiting compound having a molecular weight of 1,000 or less, which further has a group decomposable by the action of an acid and has an increased alkali solubility by the action of an acid. Item 6. The positive photosensitive composition according to Item 1. 4. The positive photosensitive composition according to claim 1, wherein a far ultraviolet light having a wavelength of 220 nm or less is used as an exposure light source.