JPH11305439A - Positive type photosensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive type photosensitive compsn. excellent in the rate of a residual film and resist profile to ArF excimer laser light and causing no defects in development by incorporating a polymer contg. units having a cycloaliphatic hydrocarbon skeleton structure, a photo-acid generating agent, a heterocyclic compd. having a specified structure, a nitrogen-contg. basic compd. and a fluorine- and/or silicon-contg. surfactant. SOLUTION: The photosensitive compsn. contains a polymer which contains a cycloaliphatic hydrocarbon skeleton structure, is decomposed by the action of an acid and becomes alkali-soluble, a compd. which generates the acid when irradiation with active rays of light or radiation, a heterocyclic compd. having a partial structure represented by the formula and a mol.wt. of <=1,000, a nitrogen-contg. basis compd. and a fluorine- and/or silicon contg. surfactant. In the formula, Z1 is O or S and Z2 is H or hydroxyl. Preferably the photosensitive compsn. further contains a low molecular acid-decomposable dissolution inhibiting compd. having groups decomposable by the action of the acid, increasing its alkali solubility by the action of the acid and having a mol.wt. of <=2,000.

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. . More specifically, the present invention relates to a positive photosensitive resin composition suitably used for fine processing of a semiconductor element using light energy rays having a short wavelength such as far ultraviolet rays, X-rays, and electron beams, and particularly to a semiconductor using an ArF excimer laser. The present invention relates to a positive photosensitive composition suitably used for fine processing of a device.

[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 the integrated circuits has reached a sub-half micron region, and further miniaturization has been 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, to manufacture DRAMs with a degree of integration up to 64 Mbits, the i-line (36
5 nm) has been used as a light source. For the mass production process of 256Mbit DRAM, KrF excimer laser (248
nm) has been put into practical use as an exposure light source.Furthermore, for the purpose of manufacturing a DRAM having an integration degree of 1 Gbit or more, a light source of a shorter wavelength is being studied, and an ArF excimer laser (193 nm), F
( ₂ ) Use of excimer laser (157 nm), X-rays, and electron beams is considered to be effective (Takumi Ueno et al., `` 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 etch resistance.For example, a novolak resin-based resist or a polyvinylphenol-based resist is used. 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 the ArF excimer laser light, it is difficult to expose even the bottom of the resist film. A good pattern with no cross-sectional shape could not be obtained.

It is known that one of the solutions to the problem of resist transparency is to use an aliphatic polymer containing no aromatic ring, for example, polymethyl methacrylate (J. Vac. Sci. Technol. , B9, 3357 (1991)). However, such a polymer cannot be practically used because sufficient dry etching resistance cannot be expected. Thus ArF
In developing resist materials for excimer laser exposure, it is the greatest challenge to achieve both improved transparency and high dry etching resistance. Therefore, a resist containing an alicyclic hydrocarbon group instead of an aromatic ring shows the same dry etching resistance as an aromatic group, and 193n
The small absorption of m was reported in Proc. SPIE, 1672, 66 (1992), and the use of the polymer has been studied energetically in recent years.

Originally, attempts to apply a polymer containing an alicyclic hydrocarbon group to a resist have been made for a long time. For example, Japanese Patent Application Laid-Open Nos. 60-195542, 1-217453, 2-59751
Discloses a norbornene-based polymer, and 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
In JP-A-9-221526, a compound in which an aliphatic cyclic hydrocarbon group having 7 to 12 carbon atoms having a bridged cyclic hydrocarbon group is linked to a side chain of a polymer, for example, tricyclo [5,2, 1,02.6]
A decane dimethylene group, a tricyclo [5,2,1,02.6] decanediyl group, a norbornanediyl group, a norbornanedimethyl group, and an adamantanediyl group are disclosed in
No. 67 discloses a compound in which a tricyclodecanyl group, a dicyclopentenyl group, a dicyclopentenyloxyethyl group, a norbornyl group, and a cyclohexyl group are linked to a side chain of a polymer.

Further, JP-A-9-325498 discloses a polymer having a cyclohexane and isobornyl skeleton in the main chain, and further disclosed in JP-A-9-230595, JP-A-9-244247, JP-A-10-10739 and WO97. -33198, EP794458, EP789278 disclose polymers in which various cyclic olefins such as dicycloolefins are introduced into the main chain, and JP-A-8-82925 and JP-A-9-230597 disclose a terpenoid skeleton. It is disclosed that a compound having a methyl group, a menthyl group or a menthyl derivative group is preferable.

[0007] Defects caused by the lithography process are one of the major factors for lowering the yield.
Recently, it has become a particularly important issue. For example, it is said that development defects are generally caused by bubbles at the time of liquid replenishment and microbubbles due to dissolved gas in the developer (Hirano et al .; Proceedings of the 42nd JSAP 27p-ZW) -9
(1996)). Recently, as the diameter of the wafer has increased and the discharge amount of the developer has increased, it has become more important to take measures against bubbles. As a countermeasure against these air bubbles, improvement of the device to discharge the developing solution softly (Science Forum Publishing, ULSI manufacturing contamination control technology, 41 (1
Attempts have been made to reduce bubbles by adding a dissolved gas degassing mechanism (see 992)), but this is not at a satisfactory level.

Further, in order to reduce development defects, a nonionic surfactant is added to the developer to improve the wettability of the developer and promote bubble desorption, and the interface in the novolak resist is improved. Attempts have been made to improve affinity by optimizing the type and amount of activator (Tasushima et al .;
Proceedings of the 2nd JSAP, 27p-ZW-7 (1996)). However, in order to reduce development defects of the chemically amplified resist for ArF using a non-aromatic polymer as described above,
These methods are not only satisfactory, but may even be counterproductive, and there has been no guidance on how to address them to reduce development defects. Moreover, when the hydrophilicity of the resist is improved to reduce development defects, the residual film ratio and the profile tend to be deteriorated, and it has been extremely difficult to achieve compatibility.

Furthermore, in a conventional positive type chemically amplified resist for KrF using an aromatic polymer, for example, Prooc.
PIE 1672,46, (1992), Prooc.SPIE 2438,551, (1995), P
rooc.SPIE, 2438,563 (1995), Prooc.SPIE 1925,14, (199
3), J. Photopolym.Sci.Tech.Vol.8.No.4,535 (1995), J.
Photopolym.Sci.Tech.Vol.5.No.1,207 (1992), J.Photop
olym.Sci.Tech.Vol.8.No.4,561 (1995), Jpn.J.Appl.Phy
As reported in s.33, 7023 (1994), etc., as the standing time from exposure to heat treatment (PEB) becomes longer, the generated acid diffuses, and the resist is exposed to basic impurities in the atmosphere. There is a problem that the acid on the surface is deactivated and the sensitivity and the profile and line width of the resist pattern after development are changed.

As a means for solving these problems, a technique of adding a basic compound such as an amine to a chemically amplified resist using an aromatic polymer is disclosed in Japanese Patent Application Laid-Open No. 63-14964.
No. 0, JP-A-5-249662, JP-A-5-127369, JP-A 5-2
No. 89322, JP-A-5-249683, JP-A-5-289340, JP-A-5-232706, JP-A-5-257282, JP-A-6-242605,
JP-A-6-242606, JP-A-6-266100, JP-A-6-266110
No., JP-A-6-317902, JP-A-7-120929, JP-A-7-14
No. 6558, JP-A-7-319163, JP-A-7-508840, JP-A-7-508840
7-333844, JP-A-7-219217, JP-A-7-92678, JP-A-7-28247, JP-A-8-22120, JP-A-8-110638,
JP-A-8-123030, JP-A-9-274312, JP-A-9-66871
No., JP-A-9-292708, JP-A-9-325496, JP-T-Hei 7-50
There are many disclosures in publications such as 8840, US5525453, US5629134 and US5667938, which are well known. However, when these amines are added to a chemically amplified resist for ArF using a non-aromatic polymer having a cycloaliphatic hydrocarbon skeleton structure, indeed, as in the case of using a non-aromatic polymer, PED is added. Is effective for the change in sensitivity and the change in the profile and line width of the resist pattern after development, but the above-mentioned development defects are extremely poor.

On the other hand, for the purpose of improving sensitivity and improving the shape of a resist pattern, it is known to add a carboxylic acid compound to a chemically amplified resist composition for excimer laser light for KrF as disclosed in JP-A-7-92679 and JP-A-5-181279. JP-A-6-214391, JP-A-9-5987, WO94 / 0
No. 1805 discloses that an amide compound or an imide compound is added.

Japanese Patent Application Laid-Open No. 9-6001 discloses a method in which an amine and a carboxylic acid compound are added to improve the sensitivity and the resolving power, and to improve the stability over time between exposure and PEB. . However, a strongly basic low-boiling amine (eg, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine) and an aromatic carboxylic acid (eg, salicylic acid, nitrobenzoic acid) disclosed in JP-A-9-6001 are preferred. Acid, phthalic acid) is added to a chemically amplified resist for ArF using a non-aromatic polymer having a cycloaliphatic hydrocarbon skeleton structure. Indeed, an excimer laser for KrF using a non-aromatic polymer As in the case of the chemically amplified resist composition for light, although an effect is seen on the stability over time between the exposure and the PEB, the development defect is extremely poor, and a countermeasure has been desired. Also, low boiling amines are
Due to the tendency to evaporate during the PEB, process effects such as no effect of the addition of the amine at all or contamination of the equipment used for semiconductor production such as a hot plate with the amine have been caused.

[0013]

SUMMARY OF THE INVENTION An object of the present invention has been made in view of the above problems, and has been made in consideration of deep ultraviolet light, in particular,
An object of the present invention is to provide a positive photosensitive composition which has excellent residual film ratio and resist profile with respect to ArF excimer laser light and does not cause a problem of development defects.

[0014]

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 polymer containing an alicyclic hydrocarbon skeleton structural unit, a photoacid generator, The present inventors have found that the object can be achieved by a combination of a nitrogen-containing basic compound having a specific structure having a molecular weight of 1000 or less, a fluorine-based and / or silicon-based surfactant, and a solvent, and have accomplished the present invention. That is, the present inventor is achieved by a method having the following configuration. (1) (A) a polymer containing a cyclic aliphatic hydrocarbon skeleton structure, which is decomposed by the action of an acid and becomes alkali-soluble, (B) a compound which generates an acid upon irradiation with actinic rays or radiation, (C) A heterocyclic compound having a partial structure represented by (Formula-1) and having a molecular weight of 1,000 or less, (D)
A positive photosensitive composition comprising a nitrogen-containing basic compound and (E) a fluorine-based and / or silicon-based surfactant.

[0015]

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(In the formula, Z ₁ represents an oxygen atom or a sulfur atom, and Z ₂ represents a hydrogen atom or a hydroxyl group.) (2) It further has a group which can be decomposed by the action of an acid, and has alkali solubility. Increased molecular weight by the action of 2000
The positive photosensitive composition according to the above (1), comprising the following low-molecular acid-decomposable dissolution inhibiting compound. (3) The positive photosensitive composition as described in any of (1) and (2) above, wherein far-ultraviolet light having a wavelength of 220 nm or less is used as an exposure light source.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the compounds used in the present invention will be described in detail. First, in the present invention, (A) having a cyclic aliphatic hydrocarbon skeleton structure, as a polymer that is decomposed by the action of an acid and becomes alkali-soluble, a conventionally known polymer can be used. As a specific example, for example, a group having a cyclic aliphatic hydrocarbon skeleton unit in the main chain represented by the following (a-1) to (a-15) and decomposing by the action of an acid (acid-decomposable group) The following (b-1) having a polymer having a cyclic aliphatic hydrocarbon skeleton in the side chain
And a polymer having an acid-decomposable group and a repeating unit represented by (b-7). In addition, the following (a-1)-(a-
15), structural units having a cyclic aliphatic hydrocarbon skeleton structure such as structural units represented by (b-1) to (b-7) are indispensable for the polymer according to the present invention, the following ( The structural units represented by c-1) to (c-4) may be included as copolymer components.

[0018]

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[0019]

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In the structural units represented by (a-1) to (a-15) and (b-1) to (b-7), A and B each independently represent a hydrogen atom,
Hydroxyl group, carboxyl group, alkoxycarbonyl group, substituted or unsubstituted alkyl group having 1 to 10 carbon atoms,
Represents an alkoxy group or an alkenyl group, and A and B may combine to form a ring; X and Y each independently represent a group decomposed by the action of an acid. Formulas (b-1) to (b-7), (c-
In 1) to (c-4), R represents a hydrogen atom, a methyl group or other alkyl group having 1 to 3 carbon atoms. Z represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkoxycarbonyl group, or a group decomposed by the action of an acid. )

In the above, examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group and a butoxycarbonyl group. 1 carbon
~ 10 alkyl groups may be substituted,
A straight-chain, branched or cyclic alkyl group is mentioned, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, t-butyl group, cyclopentyl group,
Examples include a cyclohexyl group, a hydroxymethyl group, and a hydroxyethyl group. Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, an n-butoxy group, a t-butoxy group, a propoxy group and an isopropoxy group. Examples of the alkenyl group having 2 to 10 carbon atoms include a vinyl group, an allyl group, and a 2-propenyl group. The ring formed by A and B bonded to each other includes -C (= O) -OC (= O)-, -C
(= O) -NH-C ( = O) -, - CH 2 -C (= O)
-OC (= O)-, etc. to form a ring.

The group decomposed by the action of an acid includes-
A (CH ₂ ) _n —COORa group or — (CH ₂ ) _n —
OCORb groups. Here, Ra has 2 to 2 carbon atoms.
Represents 20 hydrocarbon groups, and the hydrocarbon groups include:
Examples include a t-butyl group, a norbornyl group, and a cyclodecanyl group. Rb is a tetrahydrofuranyl group,
Represents an alkoxyethyl group such as a tetrahydropyranyl group, an ethoxyethyl group, an isopropylethyl group, a lactone group, or a cyclohexyloxyethyl group. n represents 0 or 1.

Further substituents in the above groups include:
Examples include a halogen atom, a cyano group, and a nitro group.

The polymer having the structural units represented by the above (a-1) to (a-6) can be prepared by, for example, opening a cyclic olefin in an organic solvent or a non-organic solvent in the presence of a metathesis catalyst. It is obtained by ring polymerization. Ring-opening (co) polymerization is described, for example, in WLTruett et al .; J. Am. Chem. Soc., 82, 2337 (1960) and
A. Pacreau; Macromol.Chem., 188, 2585 (1987) and JP-A-51-31800, JP-A-1-197460, JP-A-2-42094, E
It can be easily polymerized by the synthesis method described in P0789278 and the like. The metathesis catalyst used here is, for example, edited by The Society of Polymer Science of Japan: Synthesis and Reaction of Polymers (1), Kyoritsu Shuppan, p375-381 (19
92) and JP-A-49-77999, 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 tungsten or molybdenum compound is preferably 0.5 mol or more. Water, hydrogen peroxide, oxygen-containing organic compounds, nitrogen-containing organic compounds, halogen-containing organic compounds, phosphorus-containing organic compounds, sulfur-containing organic compounds, metals such as metal, Organic compounds are included, and are used in a proportion of 5 mol or less per 1 mol of the tungsten or molybdenum compound. The usage 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 ° C., preferably in an inert gas atmosphere. Specific examples of the solvent used include pentane,
Aliphatic hydrocarbons such as hexane, heptane, octane,
Alicyclic hydrocarbons such as cyclopentane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, methylene chloride, 1,1-dichloroethane, 1,2-dichloroethylene, 1-chloropropane, 1-chlorobutane, 1 Halogenated hydrocarbons such as -chloropentane, chlorobenzene, bromobenzene, o-dichlorobenzene and m-dichlorobenzene; and ether compounds such as diethyl ether and tetrahydrofuran.

The polymer used in the present invention is obtained by hydrogenating the resin 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. In addition, as the homogeneous catalyst, nickel naphthenate / triethyl aluminum, nickel acetylacetonate
And rhodium catalysts such as triethylaluminum, cobalt octenoate / n-butyllithium, titanocene dichloride / diethylaluminum monochloride, rhodium acetate, and chlorotris (triphenylphosphine) rhodium. Of these catalysts, the use of a heterogeneous catalyst is advantageous because the reaction activity is higher, the catalyst can be easily removed after the reaction, and the resulting polymer is not colored. The hydrogenation reaction is carried out at normal pressure to 300 atm, preferably 3 to 20 atm.
The reaction can be performed at 0 to 200 ° C., preferably 20 to 180 ° C. in a hydrogen gas atmosphere at 0 atm. Hydrogenation rate is usually 5
It is at least 0%, preferably at least 70%, more preferably at least 80%. If the hydrogenation ratio is less than 50%, the thermal stability and the temporal stability of the resist are undesirably deteriorated.

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

The polymers represented by (a-7) to (a-15) are usually synthesized by, for example, radical (co) polymerization of a cyclic aliphatic hydrocarbon monomer in the presence of an effective amount of a free radical initiator. it can. Specifically, J. Macromol. Sci. Chem. A-
5 (3) 491 (1971), A-5 (8) 1339 (1971), Polym.Lett.Vol.
2,469 (1964), US3143533, US3261815, US3510461
, US3793501, US3703501, and JP-A-2-46045. Preferred initiators used for radical (co) polymerization include 2,2'-azobis (2-methylpropanenitrile), benzoyl peroxide, dicumyl peroxide and the like. Usually, the concentration of the initiator will range from about 0.01 to 10% by weight, preferably from about 0.1 to 5% by weight, based on the total weight of the monomers. The reaction temperature can be changed to a high range, usually in the range of room temperature to 250 ° C, preferably in the range of 40 ° C to 200 ° C, more preferably in the range of 60 ° C to 160 ° C.

The polymerization or copolymerization is preferably carried out in an organic solvent. Solvents which dissolve the starting materials at a given temperature and also dissolve the product mixture are preferred. Preferred solvents vary depending on the type of monomers to be copolymerized, but include, for example, aromatic hydrocarbons such as toluene, aliphatic or aromatic esters such as ethyl acetate, and aliphatic ethers such as tetrahydrofuran. And the like. After the reaction for a predetermined time, it is preferable to perform distillation under reduced pressure and purification for the purpose of separating the obtained resin of the present invention from unreacted monomer components, solvents and the like. The thus obtained polymer used in the present invention is measured by gel permeation chromatography equipped with a refractive index detector by comparing the retention time with that of polystyrene having a known molecular weight, and the weight average molecular weight is determined.

Polymers having the structural units (b-1) to (b-7) or copolymer components (c-1) to (c-4)
Can be synthesized by radical (co) polymerization in the presence of an effective amount of a free radical initiator. In the polymer used in the present invention, the content of the repeating unit containing a cyclic aliphatic hydrocarbon skeleton structure is based on the repeating units of all monomers,
10 mol% or more is preferable, more preferably 20 mol% or more,
It is more preferably at least 30 mol%. In the polymer used in the present invention, the content of the repeating unit having an acid-decomposable group is 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 15 to 85 mol% in the repeating units of all monomers. 20-80 mol%. Further, in the polymer used in the present invention, (c)
The content of other copolymerization components such as the units represented by -1) to (c-4) is preferably 3 to 60 mol%, more preferably 5 to 55 mol%, of the repeating units of all monomers. More preferably, it is 10 to 50 mol%.

The polymer used in the present invention preferably has a weight average molecular weight in the range of 1,500 to 100,000, more preferably in the range of 2,000 to 70,000, particularly preferably 3,000.
It is in the range of ~ 50000. If the molecular weight is less than 1500, the dry etching resistance, heat resistance, and adhesion to the substrate are insufficient, and if the molecular weight exceeds 100,000, the resist sensitivity is undesirably reduced. Further, the degree of dispersion of the polymer used in the present invention (Mw / Mn) is preferably 1.0 to 6.0, more preferably
The heat resistance and the image performance (resist profile, defocus latitude, etc.) are better as the ratio is 1.0 to 4.0 and is smaller.

In the present invention, the amount of the polymer (A) in the photosensitive composition (excluding the solvent) is 50 to 99.7% by weight, preferably 70 to 99% by weight, based on the total solid content. is there. In the present invention, other polymers can be used in combination with the above-mentioned polymer of the present invention, if necessary.
Such other polymer may be any as long as it is compatible with the polymer of the above (A), and examples thereof include poly p-hydroxystyrene, hydrogenated poly p-hydroxystyrene, and novolak resin. In the composition of the present invention,
The preferred use range of the other polymer is 30 parts by weight or less, preferably 20 parts by weight or less, particularly preferably 10 parts by weight or less, per 100 parts by weight of the polymer in the present invention.

Next, the compound (B) of the positive photosensitive composition of the present invention which is decomposed by 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 agent, or ultraviolet light, far ultraviolet light, KrF excimer laser light, ArF excimer laser light,
A known photoacid generator and a mixture thereof can be appropriately selected and used for a microphotoresist that generates an acid by an electron beam, an X-ray, a molecular beam, or an ion beam.

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 with the polymer is sufficiently dissolved in the 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 (1
978) and other onium salts (sulfonium salt, iodonium salt, phosphonium salt, diazonium salt, ammonium salt) described in Japanese Patent Application No. 9-279071 can also be used. Specific examples of onium salts include diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzene sulfonate,
Triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, diphenyliodonium hexafluoroantimonate, triphenylsulfonium naphthalene sulfonate, triphenylsulfonyum camphorsulfonium, (4-methoxyphenyl) phenyliodonium trifluoromethanesulfonate, bis (t -Butylphenyl) iodonium trifluoromethanesulfonate;

Further, JP-A-3-103854, JP-A-3-103856
Diazodisulfones and diazoketosulfones represented by JP-A-4-1210960, JP-A-64-18143, JP-A-2-
Iminosulfonates described in 245756, JP-A-2-7127
Disulfones described in No. 0 can also be suitably used. Further, USP 3849137, JP-A-63-26653, JP-A-62
-692 63, JP-A-63-146038, JP-A-63-163452,
JP-A-62-153853, compounds in which a group capable of generating an acid by light described in JP-A-63-146029, etc. introduced into a main chain or a side chain of a polymer can also be used, and JP-A-7-25846 can be used.
No., JP-A-7-28237, JP-A-7-92675, JP-A-8-2712
Aliphatic alkylsulfonium salts having a 2-oxocyclohexyl group described in No. 0, and N-hydroxysuccinimide sulfonates, and also J. Photopolym.Sci., Tec
h., Vol. 7, No. 3, 423 (1994), etc. can also be suitably used, and they are 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 0.001 based on the total weight of the photosensitive composition (excluding the coating solvent).
Used in the range of 1 to 40% by weight, preferably 0.01 to 20% by weight
%, More preferably 0.1 to 5% by weight. If the added amount of the photoacid generator is less than 0.001% by weight, the sensitivity becomes low, and if the added amount is more than 40% by weight, the light absorption of the resist becomes too high and the profile deterioration and the process (especially baking) margin are narrow. It is not preferable.

Next, (C) a heterocyclic compound having a partial structure represented by the above formula (1) and having a molecular weight of 1,000 or less, which is used in the positive photosensitive composition of the present invention, will be described. The molecular weight is preferably from 80 to 1,000, and more preferably from 100 to 800. The partial structure represented by the above (Formula-1) is -C (= O) -NH-,
Or, -C (= O) -N (OH)-is preferable. Examples of such a heterocyclic compound (C) include, for example, o-
Benzoic acid sulfimide, 5,5-diphenylthiohydantoin, hydantoin, 5-methylthiazoline-2-thione, 10-pyrido [3,2-b] [1,4] -benzothiazine, glycine anhydride, urazole, 1-hydroxy Benzotriazole, alloxan, barbituric acid,
Examples thereof include maleimide, azauracil, azacyclononan-2-one, and those having the following structural formulas.

[0039]

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[0040]

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[0041]

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[0042]

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The amount of the compound (C) used is usually 0.001 to 100 parts by weight of the photosensitive composition (excluding the solvent).
It is 15 parts by weight, preferably 0.01 to 10 parts by weight. If the amount is less than 0.001 part by weight, the effect of the present invention cannot be sufficiently obtained. On the other hand, if it exceeds 15 parts by weight, the residual film ratio is undesirably reduced. These compounds can be used as a mixture of two or more kinds.

In addition, as long as the effects of the present invention are not impaired,
In the composition of the present invention, a low-molecular aliphatic acyclic carboxylic acid or an aromatic carboxylic acid may be mixed, but a polymer having a carboxyl group, for example, a styrene-acrylic acid copolymer,
The addition of oligomers such as a styrene-methacrylic acid copolymer and a carboxyl group-substituted norbornene polymer is not preferable because it deteriorates the resist profile.

Next, the nitrogen-containing basic compound (D) used in the positive photosensitive composition of the present invention will be described. As the nitrogen-containing basic compound, an organic amine or a basic ammonium salt or a sulfonium salt is used, as long as it does not deteriorate the sublimation or the resist performance. Amines are preferred, and solid amines having a melting point of 100 ° C. or higher are particularly preferred.

That is, JP-A-63-149640, JP-A-5-24966
No. 2, JP-A-5-127369, JP-A-5-289322, JP-A 5-2
No. 49683, JP-A-5-289340, JP-A-5-232706, JP-A-5-257282, JP-A-6-242605, JP-A-6-242606,
JP-A-6-266100, JP-A-6-266110, JP-A-6-317902
No., JP-A-7-120929, JP-A-7-146558, JP-A-7-31
No. 9163, JP-A-7-508840, JP-A-7-333844, JP-A
7-219217, JP-A-7-92678, JP-A-7-28247, JP-A-8-22120, JP-A-8-110638, JP-A-8-123030,
JP-A-9-274312, JP-A-9-66871, JP-A-9-292708
No., JP-A-9-325496, JP-T7-508840, US5525453
Nos., US5629134, US5667938, etc., organic amines and basic ammonium salts and sulfonium salts are used as long as they do not deteriorate sublimation or resist performance, and are high if they are liquid at room temperature. An amine having a boiling point of 150 ° C. is preferable, and a solid amine having a melting point of 100 ° C. or higher is particularly preferable.

Specifically, 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, piperidine, hexamethylenetetramine, imidazoles, piperazine, 4,4 ′
-Methylenebis (cyclohexylamine), tris (hydroxymethylaminomethane), 2-amino-2-methyl-1,3-propanediol, 4,4'-diaminodiphenyl ether, pyridinium p-toluenesulfonate, 2,4, 6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate, tetrabutylammonium lactate and the like can be mentioned. The amount of the nitrogen-containing basic compound used is the photosensitive composition (excluding the solvent) of 100.
Usually, 0.001 to 10 parts by weight, preferably 0.0
1 to 5 parts by weight. If the amount is less than 0.001 part by weight, the effect of the present invention cannot be sufficiently 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 be remarkably deteriorated. These compounds may be used alone or in combination of two or more.

Next, the fluorine-based and / or silicon-based surfactant (D) used in the positive photosensitive composition of the present invention will be described. Examples of the fluorine-based surfactant and / or the silicon-based surfactant include a surfactant containing a fluorine atom, a surfactant containing a silicon atom, and a surfactant containing both a fluorine atom and a silicon atom. For example, JP-A-62-36663, JP-A-61
-226746, JP-A-61-226745, JP-A-62-170950,
JP-A-63-34540, JP-A-7-230165, JP-A-8-62834
And the known fluorine-based and / or silicon-based surfactants described in JP-A-9-54432 and JP-A-9-5988, and the following commercially available surfactants can be used as they are.

For example, F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florado FC430, 431 (manufactured by Sumitomo 3M Limited), Megafac F171, F173, F176, F189,
R08 (Dainippon Ink Co., Ltd.), Surflon S-382, SC1
01, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.) and other fluorine-based and / or silicon-based surfactants, polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. Can be. Among these surfactants, a surfactant having both a fluorine atom and a silicon atom in the present invention is particularly excellent in improving development defects.

The amount of these surfactants is usually 0.01 to 2 parts by weight, preferably 0.01 to 1 part by weight, per 100 parts by weight of the solids in the composition of the present invention. It is added in proportions. These surfactants may be used alone or in some combination.

It is not well understood why the positive photosensitive composition of the present invention is specifically superior against the above-mentioned development defects. However, it is difficult to identify a heterocyclic compound having a molecular weight of 1,000 or less and a nitrogen-containing basic compound. It is thought that it was expressed by a combination of surfactants. For example, the effect cannot be realized by a combination of the nitrogen-containing basic compound and a surfactant other than the present invention, specifically, a combination of a nonionic surfactant and the like.

The positive photosensitive composition of the present invention has a group which can be decomposed by the action of an acid, if necessary, and increases the alkali solubility by the action of an acid. Blocking compounds can be included. For example, Pro
c.SPIE, 2724, 355 (1996) and JP-A-8-15865, US5310619
No., US5372912, J. Photopolym. Sci., Tech., Vol. 10, N
o.3,511 (1997)) containing acid-decomposable groups, such as cholic acid derivatives, dehydrocholic acid derivatives, deoxycholic acid derivatives, lithocholic acid derivatives, ursocholic acid derivatives and abietic acid derivatives. An alicyclic compound or an aromatic compound such as a naphthalene derivative containing an acid-decomposable group can also be used.
Further, a low-molecular acid-decomposable dissolution inhibiting compound described in JP-A-6-51519 can be used in an addition range that does not deteriorate the transmittance at 220 nm, and a 1,2-naphthoquinonediazide compound can also be used.

In the present invention, when the above-mentioned low-molecular acid-decomposable dissolution inhibiting compound is used, the amount thereof is usually in the range of 1 to 50% by weight, based on the total weight of the photosensitive composition (excluding the coating solvent). And preferably in the range of 3 to 40% by weight, more preferably 5 to 30% by weight. It has been found that the addition of these low-molecular acid-decomposable dissolution inhibiting compounds not only further improves the development defects but also has an effect on improving the dry etching resistance.

The positive photosensitive composition of the present invention may further contain, if necessary, a compound capable of accelerating dissolution in a developer, an antihalation agent, a plasticizer, a surfactant, a photosensitizer, an adhesion aid, a crosslinking agent, It may contain a photobase generator and the like.

As a suitable antihalation agent, a compound that 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 effect of multiple reflection in the resist film.

In the photosensitive composition of the present invention, the following surfactants can be used in combination for the purpose of improving coatability and developing property. Examples of such surfactants include, for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate,
Nonionic surfactants such as polyethylene glycol distearate, polyoxyethylene sorbitan monostearate, and sorbitan monolaurate are exemplified.

In order to improve the acid generation rate by 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, etc., but are not limited thereto. Absent. These photosensitizers can also be used as the antihalation agent.

After the photosensitive composition of the present invention is dissolved in a solvent capable of dissolving each of the above components, it is usually prepared, for example, with a pore size of 0.05 μm to 0.2 μm.
It is adjusted as a solution by filtering through a filter of about μm. Examples of the solvent used herein include 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, 3 -Methyl methoxypropionate, ethyl 3-ethoxypropionate, methyl β-methoxyisobutyrate, ethyl butyrate, propyl butyrate, methyl isobutyl ketone, ethyl acetate, isoamyl acetate, ethyl lactate, toluene, xylene, cyclohexyl acetate, diacetone alcohol, N -Methylpyrrolidone, N, N-dimethylformamide, γ-butyrolactone, N, N-dimethylacetamide and the like. These solvents are used alone or as a mixture. 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 resin composition of the present invention contains 10% of metal impurities such as metal and impurity components such as chlorine ion.
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 above photosensitive composition is applied on a substrate by a suitable application method such as a spinner or a coater, and then prebaked.
(Heating before exposure), exposure with exposure light having a wavelength of 220 nm or less through a predetermined mask, PEB (bake after exposure), and development can provide a good resist pattern. The substrate used here may be a substrate usually used in a semiconductor device or other manufacturing apparatus, and examples thereof include a silicon substrate, a glass substrate, and a non-magnetic ceramic substrate. 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 on these substrates. , A circuit, etc. may be built in. 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 film thickness of the resist applied on the substrate is about 0.
The range is preferably 1 μm to 10 μm, and in the case of ArF exposure, 0.1 μm
μm to 1.5 μm thickness is recommended. The resist film applied on the substrate is preferably pre-baked at a temperature of about 60 to 160 ° 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.

[0062] Commercially available UV exposure apparatus as the resist film to expose a device prebaked, X-rays exposure apparatus, an electron beam exposure apparatus, KrF excimer exposure apparatus, ArF excimer exposure system, F ₂ excimer exposure apparatus or the like is used, Particularly, in the present invention, an apparatus using an ArF excimer laser as an exposure light source is preferable. The post-exposure bake is performed for the purpose of causing the elimination of the protecting group using an acid as a catalyst, for eliminating the standing wave, and for diffusing an acid generator or the like into the film. This post-exposure bake can be performed in the same manner as the previous pre-bake. For example, the baking temperature is about 60-160 ° C, preferably about 90 ° C.
~ 150 ° C.

Examples of the developer for the photosensitive resin composition of the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, and aqueous ammonia; and 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, dimethylethanolamine, alcoholamines such as triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (T
EAH), quaternary ammonium salts such as trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo- [5,4,0] -7 -Undecene,
An aqueous alkaline solution such as a cyclic amine such as 1,5-diazabicyclo- [4,3,0] -5-nonane can be used.

Further, a suitable 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.

[0065]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. [Synthesis Example 1] Synthesis of polymer A: JP-A-9-244247, No. 4
A polymer obtained by hydrogenating the ring-opening polymer of the norbornene derivative described in the examples (the following structure) was synthesized according to the method described in EP0789278. The weight average molecular weight was 22,000.

[0066]

Embedded image

[Synthesis Example 2] Synthesis of polymer B: JP-A-9-24
No. 4247, a polymer obtained by hydrogenating the ring-opening polymer of the norbornene derivative described in the first example (the following structure) was synthesized according to the method described in EP0789278. Weight average molecular weight is 17000
Met.

[0068]

Embedded image

[Synthesis Example 3] Synthesis of polymer C: a copolymer of norbornene, maleic anhydride, t-butyl acrylate and acrylic acid (the following structure) was prepared by the method described in JP-A-10-10739, No. 7
It was synthesized according to the method described in the examples. The weight average molecular weight is 7
The molar ratio of each repeating unit is 50/25/25 (from the left in the following formula).

[0070]

Embedded image

[Synthesis Example 4] Synthesis of polymer D: A copolymer of adamantyl methacrylate and t-butyl acrylate was synthesized according to the method described in JP-A-7-234511, first example.
The weight average molecular weight is 5000, and the molar ratio of each repeating unit is 58/42 (from the left in the following formula).

[0072]

Embedded image

Synthesis Example 5 Synthesis of Acid Decomposable Low Molecular Weight Compound a A mixture of 122.7 g (0.3 mol) of cholic acid and 120 ml of thionyl chloride was refluxed for 1 hour. Excess thionyl chloride was removed, the solid obtained was dissolved in 150 ml of tetrahydrofuran, 40 g (0.35 mol) of potassium-t-butoxide were added slowly, the reaction mixture was refluxed for 6 hours, cooled and poured into water. The resulting solid was collected by filtration, washed with water and dried under reduced pressure. The purified product was recrystallized from n-hexane to obtain t-butyl cholate (the following formula) in a yield of 70%.

[0074]

Embedded image

[Examples and Comparative Examples] (Evaluation of the number of development defects) 10 g of the resin obtained in Synthesis Examples 1 to 4, 0.06 g of triphenylsulfonium triflate (PAG-1), 0.25 g of a heterocyclic compound, and acid A 0.1 μm Teflon filter made of a photosensitive composition containing 0.5 g of decomposable low-molecular compound, 0.10 g of nitrogen-containing basic compound, 0.05 g of surfactant, and 57.4 g of propylene glycol monomethyl ether acetate as a solvent with the composition shown in Table 1. By filtration. Using a spin coater, the resist was uniformly coated on a hexamethyldisilazane-treated silicon substrate, and dried by heating on a hot plate at 120 ° C. for 90 seconds to form a 0.50 μm resist film. This resist film was exposed to ArF excimer laser light through a mask, and immediately after exposure, heated on a hot plate at 110 ° 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 sample on which the contact hole pattern thus obtained was formed was subjected to KLA Tencor Co., Ltd.
The number of development defects is measured by KLA2112 machine (Threshold12, Pix
cel Size = 0.39) (the number of development defects−I). For comparison, the number of development defects was measured in the same manner for the sample developed and rinsed without exposure (Threshold 12, Pixel Si
ze = 0.39) (the number of development defects−II). Table 2 shows the results.

[0077]

[Table 1]

PAG-1: triphenylsulfonium triflate H-1: benzoxazine H-2: phthalazone H-3: saccharin H-4: benzoxazolinone H-5: benzothiazolone H-6: rhodanine H-7: Benzamide H-8: Benzanilide H-9: N-methyl-2-pyrrolidone N-1: Hexamethylenetetramine N-2: 1,5-diazabicyclo [4.3.0] -5-nonene N-3: 1,8- Diazabicyclo [5.4.0] -7-undecene N-4: 1,4-diazabicyclo [2.2.2] octane N-5: Triethylamine W-1: Megafac F176 (manufactured by Dainippon Ink Co., Ltd.) (fluorine-based interface Activator) W-2: Megafac R08 (Dai Nippon Ink Co., Ltd.) (fluorine and silicone surfactant) W-3: Polysiloxane polymer KP-341 (Shin-Etsu Chemical Co., Ltd.) (silicone type) Surfactant) W-4: Polyoxyethylene nonyl phenyl ether S-1: Propylene glycol monomethyl ether acetate

[0079]

[Table 2]

As is evident from the results in Table 2, the compositions of the present invention showed very few development defects.

[0081]

As is clear from the above, the positive photosensitive composition of the present invention has very few development defects.
Therefore, it can be effectively used particularly for forming a fine pattern required for manufacturing a semiconductor device using an ArF excimer laser beam as an exposure light source.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C08L 45/00 H01L 21/30 502R

Claims (3)

[Claims] 1. A polymer containing a cyclic aliphatic hydrocarbon skeleton structure, which is decomposed by the action of an acid to become alkali-soluble, (B) a compound which generates an acid upon irradiation with actinic rays or radiation, A) a heterocyclic compound having a partial structure represented by the following (formula-1) and having a molecular weight of 1000 or less;
(D) a nitrogen-containing basic compound, and (E) a fluorine-based compound and / or
Alternatively, a positive photosensitive composition comprising a silicon-based surfactant. Embedded image (Wherein, Z ₁ represents an oxygen atom or a sulfur atom, Z ₂
Represents a hydrogen atom or a hydroxyl group. ) 2. A low molecular weight acid-decomposable dissolution inhibiting compound having a molecular weight of 2000 or less, which further has a group decomposable by the action of an acid, and has an alkali solubility increased by the action of an acid. Item 6. The positive photosensitive composition according to Item 1. 3. The positive photosensitive composition according to claim 1, wherein far-ultraviolet light having a wavelength of 220 nm or less is used as an exposure light source.