JP4210862B2 - Pattern formation method - Google Patents

Description

  The present invention provides a pattern forming method suitable for microfabrication technology, in particular, good developer wettability in a resist material using a highly water-repellent polymer containing fluorine atoms and silicon atoms, and no pattern defects occur after development. The present invention relates to a pattern forming method.

  With the high integration and high speed of LSI, pattern rule miniaturization is progressing rapidly. The background of rapid progress in miniaturization includes higher NA of projection lenses, improved resist performance, and shorter wavelengths. In particular, the shortening of the wavelength from i-line (365 nm) to KrF (248 nm) has brought about a major change, and the mass production of 0.18 μm rule devices has become possible. A chemically amplified positive resist material using acid as a catalyst for increasing the resolution and sensitivity of the resist (described in Patent Documents 1 and 2: JP-B-2-27660, JP-A-63-27829, etc.) Has excellent characteristics and has become a mainstream resist material particularly for deep ultraviolet lithography.

Resist materials for KrF excimer lasers are generally used in 0.3 micron processes, passed through the 0.25 micron rule, and are now applied to mass production of the 0.18 micron rule. Has started, and the momentum of miniaturization has been accelerated. The shortening of the wavelength from KrF to ArF (193 nm) is expected to make the design rule finer to 0.13 μm or less, but novolak and polyvinylphenol resins that have been used in the past are around 193 nm. Since it has very strong absorption, it cannot be used as a base resin for resist. In order to ensure transparency and necessary dry etching resistance, acrylic and cycloolefin-based alicyclic resins have been studied (Patent Documents 3 to 6: JP-A-9-73173 and JP-A-10-10739). No. 9-230595, WO 97/33198). Furthermore, for F ₂ (157 nm), which can be expected to be refined to 0.10 μm or less, it becomes increasingly difficult to ensure transparency, acrylics do not transmit light at all, and cycloolefins have carbonyl bonds. Was found to have strong absorption. On the other hand, a polymer having a fluorine atom or a siloxane bond has a relatively high transmittance for the improvement of the transmittance, and the present applicant previously contains various fluorine and silicon as a resist material for F ₂ excimer laser. Proposed a polymer (Japanese Patent Application No. 11-11447, Patent Document 7: Japanese Patent Application Laid-Open No. 2001-133799, Patent Document 8: Japanese Patent Application Laid-Open No. 2001-139541, Patent Document 9: Japanese Patent Application Laid-Open No. 2001-146505, Patent Document 10: JP 2001-163945 A, Patent Document 11: JP 2001-181346 A, Japanese Patent Application No. 11-256220, Patent Document 12: JP 2001-228605 A, Patent Document 13: JP Japanese Patent Application Laid-Open No. 2001-302735, Japanese Patent Application Laid-Open No. 2002-12623, Japanese Patent Application Laid-Open No. 2001-30272. JP).

  However, fluorine and siloxane are also materials with high water repellency, and the problem of repelling alkaline water developer has surfaced. That is, since the contact angle with respect to the developing solution is high, the developing solution is not deposited on the entire surface of the wafer, or a developing defect in which the space portion is not removed due to poor penetration of the developing solution has occurred. In particular, the surface tension of the fluoropolymer was low, and in the paddle development, not only did the developer not get wet on the entire wafer surface, but in a severe case, a phenomenon that the developer bounced like a ball fell off the wafer was observed.

JP-B-2-27660 JP 63-27829 A JP-A-9-73173 Japanese Patent Laid-Open No. 10-10739 Japanese Patent Laid-Open No. 9-230595 WO97 / 33198 Japanese Patent Laid-Open No. 2001-133799 JP 2001-139441 A JP 2001-146505 A JP 2001-163945 A JP 2001-181346 A JP 2001-228605 A JP 2001-302735 A JP 2002-12623 A JP 2001-302726 A

  The present invention has been made in order to improve the above-mentioned circumstances, and even in a resist containing a base polymer having fluorine or silicon with high water repellency, the developer wettability is good and there is no occurrence of defects after development. An object is to provide a pattern forming method.

  As a result of intensive studies to achieve the above-mentioned object, the present inventor has exposed the surface of the resist film containing fluorine atoms or silicon atoms in the base polymer, post-exposure baking (PEB), and before developing the surface tension. It is effective to perform a pre-wet treatment in which an aqueous solution having a pH of 25 dyne / cm or less (25 ° C.) and a pH of 7 or less (25 ° C.) is contained. Thus, in photolithography using a photoresist, fluorine or silicon is contained. Thus, the inventors have found that it is possible to improve the wettability of a developing solution of a resist film containing a polymer having a high water repellency, and to form a resist pattern free from pattern defects after development, and have made the present invention.

  Accordingly, the present invention provides the following pattern forming method.

（式中、ａ，ｂは１〜２０の整数、ｃ，ｄ，ｅ，ｆ，ｇ，ｈ，ｉ，ｊ，ｋ，ｌ，ｍ，ｎは０〜１５の整数、ｏ，ｔは０〜１００、ｐ，ｕは１〜１００、ｑ，ｒ，ｓは０〜１５の整数である。ｖ，ｗは０＜ｖ＜１、０＜ｗ＜１、ｖ＋ｗ＝１である。Ｒ¹は、互いに同一であっても異なっていてもよく、水素原子、又は炭素数１〜４のアルキル基もしくはフッ素化されたアルキル基を示す。Ｒ²は炭素数１〜２０の直鎖状、分岐状もしくは環状のアルキル基であり、分子中に少なくとも１個以上のフッ素原子を含む。Ｒ³は水素原子、又は炭素数１〜４のアルキル基、Ｒ⁴は炭素数１〜８の２価のアルキレン基、Ｍはアミン化合物である。） Claim 1:
A resist material containing fluorine atoms or silicon atoms in a base polymer is applied to a substrate to form a resist film, and then the resist film is exposed at an exposure wavelength of 180 nm or less, post-exposure baked, and then carboxylic acid or A resist surface treating agent composition comprising an aqueous solution containing a fluorosurfactant having an amine salt of sulfonic acid as a hydrophilic group, having a surface tension at 25 ° C. of 25 dyne / cm or less and a pH at 25 ° C. of 7 or less. A pattern forming method, wherein development is performed after pre-wetting treatment in (1).
Claim 2:
The pattern forming method according to claim 1, wherein the fluorosurfactant is one or more selected from those represented by the following general formulas (1) to (18).

(Wherein, a and b are integers of 1 to 20, c, d, e, f, g, h, i, j, k, l, m, and n are integers of 0 to 15, and o and t are 0 to 0. 100, p, .R ¹ u is 1~100, q, r, s is an integer of 0~15 .v, w is 0 <v <1,0 <w < 1, v + w = 1 is, May be the same as or different from each other, and represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a fluorinated alkyl group, and R ² is linear, branched or 1 to 20 carbon atoms A cyclic alkyl group containing at least one fluorine atom in the molecule, R ³ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁴ is a divalent alkylene group having 1 to 8 carbon atoms. , M is an amine compound.)

  In the present invention, the resist film using the base polymer containing fluorine atoms or silicon atoms is subjected to a prewetting treatment for making the resist surface hydrophilic before development. This is the resist surface before development. In this method, a water-soluble compound is treated with a method such as spin coating or spraying to make it hydrophilic. In this case, increasing the wettability of the developer by pre-wetting with pure water before development is almost effective in pure water treatment because the water repellency is very high in the case of fluorine-based polymers and silicon-based polymers. Absent. That is, in order to improve the wettability of the developer, it is effective to hydrophilize the resist surface before development. It is effective to wet the surface with an aqueous solution having a low surface tension in order to make it evenly hydrophilic. When the base polymer contains fluorine, the surface water repellency is high and the surface tension is low, so that sufficient wettability cannot be exhibited unless the surface tension of the treating agent on the resist surface is lowered to 25 dyne / cm or less. . In this case, a fluorosurfactant is effective for reducing the surface tension of water. Furthermore, in this prewetting method, the resist is developed by prewetting unless the pH of the aqueous solution is set to an acidity of 7 or less. If the development proceeds before the original development, there may be a problem in the line width control and sensitivity stability after the development.

  According to the present invention, it is possible to improve the wettability of a resist film using a base polymer containing a fluorine atom or a silicon atom with respect to a developing solution, and it is possible to form a resist pattern free from defects due to poor development.

Hereinafter, the present invention will be described in more detail.
The resist surface treating agent composition (pre-wetting agent) of the present invention forms a resist film by applying a resist material containing fluorine atoms or silicon atoms in a base polymer to a substrate, and then exposing the resist film to post-exposure. It is used for pre-wetting treatment after post-exposure bake and before development when performing baked (PEB) and then developing. Surface tension at 25 ° C. is 25 dyne / cm or less, preferably 24 dyne / cm or less More preferably, it is 12-23 dyne / cm. Moreover, pH at 25 degreeC is 7 or less, Preferably it is 1-7, More preferably, it is 1-6, More preferably, it is 2-5.

  Here, as described above, the surface tension needs to be 25 dyne / cm or less in order to make the resist surface evenly hydrophilic, but in order to reduce the surface tension of the prewetting agent to 25 dyne / cm or less, a fluorine-based material is required. It is effective to add a surfactant. In this case, the hydrophilic group of the surfactant is classified into an anionic type, a cationic type, a nonionic type, and a betaine type. As characteristics of the prewetting liquid, it is necessary not to mix with the resist surface and not to dissolve the surface. Therefore, the nonionic type added to the resist, the cationic type containing a basic group, and the betaine type are not desirable. Even in the anion type, those containing an alkali metal are not preferable because they lead to metal contamination during device fabrication. Accordingly, amine salts of carboxylic acid or sulfonic acid are the most preferred hydrophilic groups. Such a fluorosurfactant is preferably an anionic perfluoro compound containing carboxylic acid or sulfonic acid and an amine compound as a counter anion, and those represented by the following formulas (1) to (18) are preferable. It is.

（式中、ａ，ｂは１〜２０の整数、ｃ，ｄ，ｅ，ｆ，ｇ，ｈ，ｉ，ｊ，ｋ，ｌ，ｍ，ｎは０〜１５の整数、ｏ，ｔは０〜１００、ｐ，ｕは１〜１００、ｑ，ｒ，ｓは０〜１５の整数である。ｖ，ｗは０＜ｖ＜１、０＜ｗ＜１、ｖ＋ｗ＝１である。Ｒ¹は、互いに同一であっても異なっていてもよく、水素原子、又は炭素数１〜４のアルキル基もしくはフッ素化されたアルキル基を示す。Ｒ²は炭素数１〜２０の直鎖状、分岐状もしくは環状のアルキル基であり、分子中に少なくとも１個以上のフッ素原子を含む。Ｒ³は水素原子、又は炭素数１〜４のアルキル基、Ｒ⁴は炭素数１〜８の２価のアルキレン基、Ｍはアミン化合物である。）

(Wherein, a and b are integers of 1 to 20, c, d, e, f, g, h, i, j, k, l, m, and n are integers of 0 to 15, and o and t are 0 to 0. 100, p, .R ¹ u is 1~100, q, r, s is an integer of 0~15 .v, w is 0 <v <1,0 <w < 1, v + w = 1 is, May be the same as or different from each other, and represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a fluorinated alkyl group, and R ² is linear, branched or 1 to 20 carbon atoms A cyclic alkyl group containing at least one fluorine atom in the molecule, R ³ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁴ is a divalent alkylene group having 1 to 8 carbon atoms. , M is an amine compound.)

Here, the alkyl groups of R ¹ and R ³ are a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and the like. Those in which some or all of the hydrogen atoms are substituted with fluorine atoms, such as difluoromethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoro A propyl group, 2,2,3,3-tetrafluoropropyl group, 2,2,3,3,3-pentafluoropropyl group and the like can be mentioned. Examples of the alkyl group for R ² include methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group, decyl group. Groups and the like. Examples of the alkylene group for R ⁴ include a methylene group, an ethylene group, a propylene group, a trimethylene group, and a tetramethylene group.

  Examples of the amine compound of M include primary, secondary, and tertiary aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, and sulfonyl groups. A nitrogen-containing compound having a hydroxy group, a nitrogen-containing compound having a hydroxy group, a nitrogen-containing compound having a hydroxyphenyl group, an alcoholic nitrogen-containing compound, an amide derivative, an imide derivative, and the like. Particularly, an aliphatic amine is preferably used.

  Specifically, primary aliphatic amines include ammonia, methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, pentylamine, tert- Amylamine, cyclopentylamine, hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, dodecylamine, cetylamine, methylenediamine, ethylenediamine, tetraethylenepentamine, etc. are exemplified as secondary aliphatic amines. Dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, dipentylamine, disi Lopentylamine, dihexylamine, dicyclohexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, didodecylamine, dicetylamine, N, N-dimethylmethylenediamine, N, N-dimethylethylenediamine, N, N-dimethyltetraethylenepenta Examples of tertiary aliphatic amines include trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-sec-butylamine, and tripentylamine. , Tricyclopentylamine, trihexylamine, tricyclohexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, tridodecylamine, Cetylamine, N, N, N ′, N′-tetramethylmethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethyltetraethylenepentamine, triethylenediamine (DABCO) etc. are illustrated.

  Examples of hybrid amines include dimethylethylamine, methylethylpropylamine, benzylamine, phenethylamine, and benzyldimethylamine. Specific examples of aromatic amines and heterocyclic amines include aniline derivatives (eg, aniline, N-methylaniline, N-ethylaniline, N-propylaniline, N, N-dimethylaniline, 2-methylaniline, 3- Methylaniline, 4-methylaniline, ethylaniline, propylaniline, trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,5- Dinitroaniline, N, N-dimethyltoluidine, etc.), diphenyl (p-tolyl) amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole derivatives (eg pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4-dim Lupyrrole, 2,5-dimethylpyrrole, N-methylpyrrole, etc.), oxazole derivatives (eg oxazole, isoxazole etc.), thiazole derivatives (eg thiazole, isothiazole etc.), imidazole derivatives (eg imidazole, 4-methylimidazole, 4 -Methyl-2-phenylimidazole, etc.), pyrazole derivatives, furazane derivatives, pyrroline derivatives (eg pyrroline, 2-methyl-1-pyrroline etc.), pyrrolidine derivatives (eg pyrrolidine, N-methylpyrrolidine, pyrrolidinone, N-methylpyrrolidone etc.) ), Imidazoline derivatives, imidazolidine derivatives, pyridine derivatives (eg pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 4- (1-butylpentyl) pyridine, dimethyl) Lysine, trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, 4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridine, 4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine, 2- (1-ethylpropyl) pyridine, aminopyridine, dimethylaminopyridine, etc.), pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine Derivatives, piperazine derivatives, morpholine derivatives, indole derivatives, isoindole derivatives, 1H-indazole derivatives, indoline derivatives, quinoline derivatives (eg quinoline, 3-quinoline carbo Nitriles), isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxaline derivatives, phthalazine derivatives, purine derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenazine derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine Examples include derivatives, guanine derivatives, guanosine derivatives, uracil derivatives, uridine derivatives and the like.

  Furthermore, examples of the nitrogen-containing compound having a carboxy group include aminobenzoic acid, indolecarboxylic acid, amino acid derivatives (for example, nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine, methionine. , Phenylalanine, threonine, lysine, 3-aminopyrazine-2-carboxylic acid, methoxyalanine and the like) and nitrogen-containing compounds having a sulfonyl group include 3-pyridinesulfonic acid, pyridinium p-toluenesulfonate, and the like. , Nitrogen-containing compounds having a hydroxy group, nitrogen-containing compounds having a hydroxyphenyl group, and alcoholic nitrogen-containing compounds include 2-hydroxypyridine, aminocresol, 2,4-quinolinediol, 3-indoleme Nord hydrate, monoethanolamine, diethanolamine, triethanolamine, N-ethyldiethanolamine, N, N-diethylethanolamine, triisopropanolamine, 2,2'-iminodiethanol, 2-aminoethanol, 3-amino-1 -Propanol, 4-amino-1-butanol, 4- (2-hydroxyethyl) morpholine, 2- (2-hydroxyethyl) pyridine, 1- (2-hydroxyethyl) piperazine, 1- [2- (2-hydroxy) Ethoxy) ethyl] piperazine, piperidine ethanol, 1- (2-hydroxyethyl) pyrrolidine, 1- (2-hydroxyethyl) -2-pyrrolidinone, 3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2 -Propanediol, 8-hydroxy Yurolidine, 3-cuincridinol, 3-tropanol, 1-methyl-2-pyrrolidine ethanol, 1-aziridine ethanol, N- (2-hydroxyethyl) phthalimide, N- (2-hydroxyethyl) isonicotinamide, etc. Illustrated. Examples of amide derivatives include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide and the like. Examples of imide derivatives include phthalimide, succinimide, maleimide and the like.

  Furthermore, it can also be set as the basic compound shown by the following general formula (19) and (20).

（式中、Ｒ⁴¹、Ｒ⁴²、Ｒ⁴³、Ｒ⁴⁷、Ｒ⁴⁸はそれぞれ独立して直鎖状、分岐鎖状又は環状の炭素数１〜２０のアルキレン基、Ｒ⁴⁴、Ｒ⁴⁵、Ｒ⁴⁶、Ｒ⁴⁹、Ｒ⁵⁰は水素原子、炭素数１〜２０のアルキル基又はアミノ基を示し、Ｒ⁴⁴とＲ⁴⁵、Ｒ⁴⁵とＲ⁴⁶、Ｒ⁴⁴とＲ⁴⁶、Ｒ⁴⁴とＲ⁴⁵とＲ⁴⁶、Ｒ⁴⁹とＲ⁵⁰はそれぞれ結合して環を形成してもよい。Ｓ、Ｔ、Ｕはそれぞれ０〜２０の整数を示す。但し、Ｓ、Ｔ、Ｕ＝０のとき、Ｒ⁴⁴、Ｒ⁴⁵、Ｒ⁴⁶、Ｒ⁴⁹、Ｒ⁵⁰は水素原子を含まない。）

Wherein R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁷ and R ⁴⁸ are each independently a linear, branched or cyclic alkylene group having 1 to 20 carbon atoms, R ⁴⁴ , R ⁴⁵ , R ⁴⁶ , R ⁴⁹ and R ⁵⁰ represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an amino group, R ⁴⁴ and R ⁴⁵ , R ⁴⁵ and R ⁴⁶ , R ⁴⁴ and R ⁴⁶ , R ⁴⁴ and R ⁴⁵ and R ⁴⁶ , R ⁴⁹ and R ⁵⁰ may be bonded to each other to form a ring, and S, T and U each represent an integer of 0 to 20, provided that when S, T and U = 0, R ⁴⁴ , R ⁴⁵ , R ⁴⁶ , R ⁴⁹ and R ⁵⁰ do not contain a hydrogen atom.)

Here, the alkylene group for R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁷ and R ⁴⁸ has 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms. Specifically, , Methylene group, ethylene group, n-propylene group, isopropylene group, n-butylene group, isobutylene group, n-pentylene group, isopentylene group, hexylene group, nonylene group, decylene group, cyclopentylene group, cyclohexylene group Etc.

The alkyl group for R ⁴⁴ , R ⁴⁵ , R ⁴⁶ , R ⁴⁹ , and R ⁵⁰ has 1 to 20 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and these are linear. , Branched or annular. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, hexyl group, nonyl group, decyl group, dodecyl Group, tridecyl group, cyclopentyl group, cyclohexyl group and the like.

Further, when R ⁴⁴ and R ⁴⁵ , R ⁴⁵ and R ⁴⁶ , R ⁴⁴ and R ⁴⁶ , R ⁴⁴ and R ⁴⁵ and R ⁴⁶ , and R ⁴⁹ and R ⁵⁰ form a ring, the number of carbon atoms in the ring is 1 to 20 More preferably, it is 1-8, More preferably, it is 1-6, Moreover, the C1-C6, especially 1-4 alkyl group may branch these rings.

  S, T, and U are each an integer of 0 to 20, more preferably 1 to 10, and still more preferably an integer of 1 to 8.

  Specific examples of the compounds of the above formulas (19) and (20) include tris {2- (methoxymethoxy) ethyl} amine, tris {2- (methoxyethoxy) ethyl} amine, tris [2-{(2-methoxy Ethoxy) methoxy} ethyl] amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, Tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2-{(2-hydroxyethoxy) ethoxy} ethyl] amine, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo [8.8.8] hexacosane, 4,7,13,18-tetraoxa-1,10-diazabicyclo [8.5.5] eicosane 1,4,10,13-tetraoxa-7,16-diazabicyclooctadecane, 1-aza-12-crown-4, 1-aza-15-crown-5, 1-aza-18-crown-6, etc. Can be mentioned. Especially tertiary amines, aniline derivatives, pyrrolidine derivatives, pyridine derivatives, quinoline derivatives, amino acid derivatives, nitrogen-containing compounds having a hydroxy group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amide derivatives, imide derivatives, Tris {2- (methoxymethoxy) ethyl} amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris [2-{(2-methoxyethoxy) methyl} ethyl] amine, 1-aza-15-crown -5 etc. are preferred.

  Here, the pH of the prewetting agent of the present invention may be adjusted by adding an acid or an alkali, but the pH can be controlled by the mixing ratio of perfluoroalkylcarboxylic acid or sulfonic acid and amine. . Increasing the ratio of amine to perfluoroalkylcarboxylic acid or sulfonic acid increases the pH and increases the basicity. If the basicity is too high, the exposed portion of the resist after wet processing will dissolve, and if the resist dissolves before development, it will be difficult to control dissolution during development, resulting in variations in pattern dimensions within the wafer and changes in sensitivity. Happens.

  On the other hand, when the ratio of amine is small, the pH is lowered and an acidic aqueous solution is obtained. If the wet processing aqueous solution is acidic, the exposed portion of the resist is not dissolved, and dissolution proceeds only by development. However, if the amount of amine added is too small, the fluorosurfactant becomes insoluble in water.

  The addition amount of the fluorosurfactant in the prewetting agent of the present invention may be used so that the surface tension at 25 ° C. is 25 dyne / cm or less, but is usually 0.0001 to 10% by weight, particularly 0.001. Used to a concentration of ˜5% by weight. If the amount of the fluorosurfactant is too small, the wettability may be insufficient. If the amount is too large, the resist surface may be dissolved or mixed with the resist layer and the pattern shape may be reduced or the T-top may be formed. .

  In order to improve the film-forming property, the prewetting agent includes various water-soluble polymers such as polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, polyvinylpyrrolidone, polyethylene oxide, amylose, dextran, cellulose, and pullulan. It is optional to add 0 to 1,000 parts by weight with respect to 100 parts by weight of the surfactant.

  The water-soluble material easily generates bubbles (Matthew et al., J. of Coating Technology, 27, Vol. 66, No. 83 March (1994)). Have been reported (42th Applied Physics Lecture 29P-S-5, 43rd Applied Physics Lecture 27P-2W-7, 27P-2W-9). In order to reduce microbubbles, a method of adding an antifoaming agent is common. In general, antifoaming agents for aqueous solutions include soybean oil, corn oil, olive oil, linseed oil, castor oil, lard oil and other natural fats and oils, long-chain alcohols such as amyl alcohol and octyl alcohol, and silicone resins. Although generally known, these are materials that have low or no hydration. The material is excellent in defoaming properties, but when it is added to a water-soluble material and film formation is performed by spin coating, uneven coating occurs and film formation cannot be performed uniformly. In order to form a film uniformly by spin coating, an antifoaming agent having high hydration properties is required. Examples of highly dehydrating antifoaming agents include alcohols such as methanol, ethanol, isopropyl alcohol, n-butyl alcohol, n-hexyl alcohol, and ethylene glycol, or acetylenes represented by the following general formulas (21) and (22) An antifoaming agent can be used.

Here, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁷ , R ¹⁸ and R ¹⁹ are the same or different hydrogen atoms or alkyl groups having 1 to 20 carbon atoms, and R ¹⁵ , R ¹⁶ and R ²⁰ are carbon atoms. The alkylene group of number 1-10, M, N, and O are integers of 0-20. The blending amount of these antifoaming agents is preferably 0 to 1,000 parts by weight with respect to 100 parts by weight of the surfactant in the prewetting agent.

  In the pattern forming method of the present invention, a resist material containing a fluorine atom or a silicon atom in a base polymer is applied onto a substrate such as a wafer, followed by exposure and post-exposure baking (PEB). A hydrophilic treatment for treating the resist film with an agent is performed and developed.

  Here, the resist material may be a positive type or a negative type, and may be a chemical amplification type or a non-chemical amplification type, but a chemical amplification type, particularly a chemical amplification positive type is preferable. The composition of the resist material can be a normal composition corresponding to the type of the resist material. In the present invention, a resist polymer containing a fluorine atom or a silicon atom is used as the base polymer of the resist material.

Examples of such a base polymer include WO 00 / 17712A, US Pat. No. 4,963,471, JP-A No. 2001-133799, JP-A No. 2001-139541, JP-A No. 2001-146505, JP-A No. 2001-163945, and JP-A No. 2001-181346. Japanese Patent Application No. 11-256220, JP-A No. 2001-228605, JP-A No. 2001-302735, JP-A No. 2002-12623, and JP-A No. 2001-302726 are used. A polymer comprising a unit in which a part or all of hydrogen atoms such as a polyhydroxystyrene unit, a (meth) acryl unit and a cycloolefin unit are substituted with a fluorine-containing group such as a fluorine atom or a fluorinated alkyl group compounds, RSiO _3/2 units (R is an organic group) or the Some or all fluorine atoms of the hydrogen atom of the group, but a polymer compound containing a unit substituted with a fluorine-containing group such as a fluorinated alkyl group, and the like, but is not limited thereto.

  In the case of a chemically amplified positive resist material, it has a unit containing the above fluorine atom or silicon atom, has an acid labile group, is hardly soluble or insoluble in alkali before exposure, and is generated from an acid generator by exposure. A polymer compound in which an acid labile group is eliminated by an acid and becomes alkali-soluble is used as a base polymer, and an acid generator, a basic compound, and the like are blended therein.

  In addition, a surfactant conventionally used for improving the coating property can be added to the resist material of the present invention. In addition, the addition amount can be made into a normal amount in the range which does not prevent the effect of this invention.

  Examples of the surfactant include perfluoroalkyl polyoxyethylene ethanol, fluorinated alkyl ester, perfluoroalkylamine oxide, and fluorine-containing organosiloxane compound. For example, Florard “FC-430”, “FC-431” (all manufactured by Sumitomo 3M Limited), Surflon “S-141”, “S-145”, “S-381”, “S-383” (any Manufactured by Asahi Glass Co., Ltd.), Unidyne "DS-401", "DS-403", "DS-451" (all manufactured by Daikin Industries, Ltd.), MegaFuck "F-8151", "F-171" , “F-172”, “F-173”, “F-177” (all manufactured by Dainippon Ink and Co., Ltd.), “X-70-092”, “X-70-093” (all Shin-Etsu) Chemical Industry Co., Ltd.). Preferably, Florard “FC-430” (manufactured by Sumitomo 3M Co., Ltd.), “X-70-093” (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used.

In the pattern forming method of the present invention, the steps up to PEB can be carried out by a conventional method according to the type of resist material, etc., but the exposure is F ₂ , Kr ₂ , Ar ₂ excimer laser light having a wavelength of 180 nm or less, It is preferable to carry out with 1-20 nm soft X-rays. The prewetting treatment with the prewetting agent is not particularly limited, but a prewetting agent (a method of applying a hydrophilic treatment by spin coating or spraying an aqueous solution and applying a hydrophilic treatment is employed. May be at room temperature, and the treatment time is usually 0.1 to 60 seconds, particularly 0.5 to 30 seconds.

  After such hydrophilic treatment, development can be performed by discharging the developer from the developer nozzle. In this case, the developing solution is selected depending on the type of resist material, etc., but usually an alkaline developing solution is used, and in particular, tetramethylammonium hydroxide or a choline hydroxide 0.001 to 10% by weight aqueous solution is used. A 2.38 wt% aqueous solution is generally used. Either a developer to which a surfactant is added or a developer to which a surfactant is not added can be used. Note that conventional methods can be employed for the development method and conditions.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following example.

[Example]
0.7 mol of ethanolamine is added to 1 g of the fluorine compound of F1 to F17 shown below and 1 mol of the carboxylic acid or sulfonic acid of the fluorine compound, and sufficiently dissolved in 200 g of pure water, 0.1 μm size A pre-wet aqueous solution was prepared by filtration through a filter. Under an environment of 25 ° C., the pH value of the pre-wet aqueous solution was measured with a pH meter, and the surface tension was measured with a surface tension meter. The results are shown in Table 1.

  100 parts by weight of a polymer represented by the following general formula, 2 parts by weight of an acid generator, 0.1 part by weight of tributylamine as a basic compound are sufficiently dissolved in 1000 parts by weight of propylene glycol monomethyl ether acetate (PGMEA), and 0.1 μm. A resist solution was prepared by filtering through a size filter.

  An antireflection film (DUV-30) manufactured by Brewer Science Co., Ltd. (55 nm) is prepared on an 8-inch wafer, the resist solution is spin-coated thereon, and prebaked at 100 ° C. for 90 seconds on a hot plate. A resist film having a thickness of 200 nm was prepared. The resist substrate was exposed with a Nikon KrF excimer laser scanner (S203A, NA 0.68), baked at 110 ° C. for 90 seconds (PEB), and then the above pre-wet aqueous solution was dispensed onto the resist film, first at 300 rpm for 3 seconds. Thereafter, the resist surface was subjected to hydrophilic treatment by rotating at 4000 rpm for 5 seconds.

  Subsequently, development was performed for 60 seconds with a 2.38 wt% aqueous solution of tetramethylammonium hydroxide (TMAH) (no surfactant added). The repelling state of the developer at this time was visually observed. Further, the resist pattern shape after development (cross-sectional shape of a 0.15 μm line and space pattern) was observed by SEM.

[Comparative example]
As a comparative example, when the same resist film as in the example was formed and developed without prewetting, the hydrocarbon surfactant shown in C-1 (the amount of ethanolamine added to 1 mol of sulfonic acid was 0.7 When processed and developed with a prewet aqueous solution containing 2 moles), treated with a prewet aqueous solution in which the amount of ethanolamine added to 1 mole of carboxylic acid is 2 moles using fluorine compounds F-1 and F-2. Table 2 shows the results of development. The preparation of the prewetting aqueous solution and the measurement of pH and surface tension are the same as in the examples.

Claims (2)

  A resist material containing fluorine atoms or silicon atoms in a base polymer is applied to a substrate to form a resist film, and then the resist film is exposed at an exposure wavelength of 180 nm or less, post-exposure baked, and then carboxylic acid or A resist surface treating agent composition comprising an aqueous solution containing a fluorosurfactant having an amine salt of sulfonic acid as a hydrophilic group, having a surface tension at 25 ° C. of 25 dyne / cm or less and a pH at 25 ° C. of 7 or less. A pattern forming method, wherein development is performed after pre-wetting treatment in (1). The pattern forming method according to claim 1, wherein the fluorosurfactant is one or more selected from those represented by the following general formulas (1) to (18).

(Wherein, a and b are integers of 1 to 20, c, d, e, f, g, h, i, j, k, l, m, and n are integers of 0 to 15, and o and t are 0 to 0. 100, p, .R ¹ u is 1~100, q, r, s is an integer of 0~15 .v, w is 0 <v <1,0 <w < 1, v + w = 1 is, May be the same as or different from each other, and represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a fluorinated alkyl group, and R ² is linear, branched or 1 to 20 carbon atoms A cyclic alkyl group containing at least one fluorine atom in the molecule, R ³ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁴ is a divalent alkylene group having 1 to 8 carbon atoms. , M is an amine compound.)