JP5263424B2 - Positive photosensitive resin composition, method for producing resist pattern, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive photosensitive resin composition developable with an aqueous alkaline solution, which has further improved sensitivity and resolution. <P>SOLUTION: A positive photosensitive resin composition contains (A) an alkali-soluble resin having a phenolic hydroxyl group, (B) a compound generating an acid with light, (C) an elastomer, (D) a low molecular weight compound having a phenolic hydroxyl group and (E) a solvent, where the (D) component is 2,2-bisä3,5-bis(hydroxymethyl)-4-hydroxyphenyl}-1,1,1,3,3,3-hexafluoropropane or 1,1-bisä3,5-bis(methoxymethyl)-4-hydroxyphenyl}methane. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a positive photosensitive resin composition, a method for producing a resist pattern, and an electronic device.

  In recent years, semiconductor devices have been highly integrated and increased in size, and there has been a demand for thinner and smaller sealing resin packages. Along with this, it is required to form the surface protective layer and interlayer insulating film of the semiconductor element and the rewiring layer of the semiconductor package with materials having more excellent electrical characteristics, heat resistance, mechanical characteristics, and the like. Polyimide resin is one of the materials that can satisfy such required characteristics. For example, use of photosensitive polyimide obtained by imparting photosensitive characteristics to polyimide resin has been studied. When photosensitive polyimide is used, there is an advantage that a pattern forming process is simplified and a complicated manufacturing process can be shortened (for example, refer to Patent Documents 1 and 2).

  The polyimide resin film is generally formed by thinning a solution of a polyimide precursor (polyamic acid) obtained by reacting tetracarboxylic dianhydride and diamine (so-called varnish) by a method such as spin coating, and thermally dehydrating and ring-closing. (For example, refer nonpatent literature 1). The polyimide resin is cured through this dehydration ring closure process. However, in the case of a polyimide resin using a polyimide precursor, there is a problem that volume shrinkage due to dehydration (imidization) occurs during curing, resulting in a loss of film thickness and a decrease in dimensional accuracy. In addition, recently, a film formation process at a low temperature is desired, and a polyimide resin that can perform dehydration and ring closure at a low temperature but has properties comparable to those obtained by dehydration and ring closure at high temperatures. Is required. However, when the polyimide precursor is cured at a low temperature, imidization is incomplete, so that the formed cured film becomes brittle and the physical properties thereof are lowered.

  On the other hand, photosensitive resins using other polymers that do not require dehydration and ring closure like a polyimide precursor and have high heat resistance have been studied (for example, Non-Patent Document 2 and Patent Documents 3 to 7). Particularly in recent years, in applications such as a rewiring layer of a semiconductor package, a positive photosensitive resin composition capable of forming a pattern having high heat resistance while being developable with an alkaline aqueous solution is required from the viewpoint of reducing environmental burden. ing.

JP-A-49-115541 JP 59-108031 A International Publication No. 2004/006020 Pamphlet JP 2006-106214 A JP 2004-2754 A Japanese Patent Laid-Open No. 2004-190008 Japanese Patent No. 3812654

Japan Polyimide Study Group "Latest Polyimides-Fundamentals and Applications" (2002) J. et al. Photopolym. Sci. Technol. 2005, Volume 18, p. 321-325

  However, the conventional positive photosensitive resin composition that can be developed with an alkaline aqueous solution has some good characteristics in terms of heat resistance and the like, but further improvements have been required in terms of sensitivity and resolution.

  Therefore, an object of the present invention is to further improve sensitivity and resolution in a positive photosensitive resin composition that can be developed with an alkaline aqueous solution. Further, the present invention provides a method for forming a resist pattern having good heat resistance with sufficiently high sensitivity and resolution using a positive photosensitive resin composition, and an electron having a resist pattern formed by such a method. An object is to provide an electronic device including a component.

  The positive photosensitive resin composition of the present invention comprises (A) an alkali-soluble resin having a phenolic hydroxyl group, (B) a compound that generates an acid by light, (C) an elastomer, and (D) a low molecule having a phenolic hydroxyl group. A compound and (E) a solvent.

  According to such a positive photosensitive resin composition, it is possible to form a resist pattern with sufficiently high sensitivity and resolution. The reason why such an effect can be obtained by the positive photosensitive resin composition of the present invention is not necessarily clear, but the present inventors consider as follows.

  That is, the positive photosensitive resin composition of the present invention is considered to have sufficiently high sensitivity because the dissolution rate of the exposed portion in the alkaline aqueous solution increases when the resist pattern is produced. Furthermore, in the positive photosensitive resin composition of the present invention, it is easy to dissolve the exposed portion with an alkaline aqueous solution when producing a resist pattern, so the solubility of the unexposed portion and the exposed portion in the alkaline aqueous solution is increased. It is considered that the difference between the two increases and the resolution improves.

  The component (A) is preferably a phenol resin because of its low cost and small volume shrinkage during curing. The component (A) is also preferably a vinyl polymer containing a monomer unit having a phenolic hydroxyl group because of excellent electrical characteristics (insulating properties) and small volume shrinkage during curing.

  In the positive photosensitive resin composition of the present invention, since the resolution at the time of forming a resist pattern is further improved, 1 to 50 parts by weight of component (D) with respect to 100 parts by weight of component (A). It is preferable to contain.

  The component (B) is preferably an o-quinonediazide compound because sensitivity at the time of forming a resist pattern is further improved.

  The positive photosensitive resin composition of the present invention preferably further contains (F) a compound that generates an acid by heating. According to this, it becomes possible to generate an acid when heating the photosensitive resin film, the reaction between the component (A) and the component (D), that is, the thermal crosslinking reaction is promoted, and the heat resistance of the cured film is increased. improves.

  Further, the method for producing a resist pattern of the present invention comprises a step of exposing a photosensitive resin film comprising the above-described positive photosensitive resin composition, and patterning the exposed photosensitive resin film by developing with an alkaline aqueous solution. And a step of heating the patterned photosensitive resin film. According to such a manufacturing method, since the positive photosensitive resin composition described above is used, a resist pattern having good heat resistance can be formed with sufficiently high sensitivity and resolution.

  In the method for producing a resist pattern of the present invention, the patterned photosensitive resin film is preferably heated to 200 ° C. or lower. Thereby, the damage by the heat | fever with respect to an electronic device can fully be prevented.

  Furthermore, the electronic device of the present invention includes an electronic component having a resist pattern formed by the above-described manufacturing method as an interlayer insulating film or a surface protective layer. Since such an electronic device has a resist pattern formed from the above-described positive photosensitive resin composition, it exhibits excellent effects.

  The present invention provides a positive photosensitive resin composition capable of forming a resist pattern having a good shape, having a sufficiently high sensitivity and resolution, good adhesion during development and good heat resistance. . According to the positive photosensitive resin composition of the present invention, since a resist pattern can be formed by a low-temperature heating process of 200 ° C. or lower, damage to an electronic device due to heat can be prevented, and the reliability is high. Electronic components can be provided with high yield.

  Further, the present invention provides a method for forming a resist pattern having good heat resistance with sufficiently high sensitivity and resolution using a positive photosensitive resin composition, and an electron having a resist pattern formed by such a method. An electronic device having a component is provided. The resist pattern formed by the method of the present invention has a good shape and characteristics, and has a small dimensional stability because of a small volume shrinkage during curing.

It is a schematic sectional drawing explaining one Embodiment of the manufacturing process of a semiconductor device. It is a schematic sectional drawing explaining one Embodiment of the manufacturing process of a semiconductor device. It is a schematic sectional drawing explaining one Embodiment of the manufacturing process of a semiconductor device. It is a schematic sectional drawing explaining one Embodiment of the manufacturing process of a semiconductor device. It is a schematic sectional drawing explaining one Embodiment of the manufacturing process of a semiconductor device. It is a schematic sectional drawing which shows one Embodiment of an electronic component (semiconductor device). It is a schematic sectional drawing which shows one Embodiment of an electronic component (semiconductor device).

  Hereinafter, an embodiment of a positive photosensitive resin composition, a resist pattern manufacturing method, and an electronic component according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the following embodiment.

[Positive photosensitive resin composition]
The positive photosensitive resin composition of the present invention comprises (A) an alkali-soluble resin having a phenolic hydroxyl group, (B) a compound that generates an acid by light, (C) an elastomer, and (D) a low molecule having a phenolic hydroxyl group. A compound and (E) a solvent. Hereinafter, each component contained in the positive photosensitive resin composition will be described.

<(A) component>
The component (A) is a resin having a phenolic hydroxyl group in the molecule and soluble in alkali. Specific examples thereof include a vinyl polymer containing a monomer unit having a phenolic hydroxyl group such as poly (hydroxystyrene), a phenol resin, a polybenzoxazole precursor, poly (hydroxyamide), poly (hydroxyphenylene) ether, polynaphthol. Is mentioned.

  Among these, a phenol resin is preferable and a novolac type phenol resin is particularly preferable because of low cost and small volume shrinkage at the time of curing. In addition, a vinyl polymer containing a monomer unit having a phenolic hydroxyl group, particularly poly (hydroxystyrene) is also preferred because of excellent electrical characteristics (insulating properties) and small volume shrinkage during curing.

(Phenolic resin)
As a phenol resin, what is obtained by condensing (reaction) a phenol derivative and aldehydes in presence of catalysts, such as an acid or a base, can be used, for example. Among these, a phenol resin obtained when an acid catalyst is used is particularly referred to as a novolac type phenol resin.

  Examples of the phenol derivative used for obtaining the phenol resin include phenol; o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, and m-butylphenol. P-butylphenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, Alkylphenols such as 3,4,5-trimethylphenol; alkoxyphenols such as methoxyphenol and 2-methoxy-4-methylphenol; alkenylphenols such as vinylphenol and allylphenol; aralkylphenols such as benzylphenol; Alkoxycarbonylphenols such as toxylcarbonylphenol; Arylcarbonylphenols such as benzoyloxyphenol; Halogenated phenols such as chlorophenol; Polyhydroxybenzenes such as catechol, resorcinol and pyrogallol; Bisphenols such as bisphenol A and bisphenol F; α- or β A naphthol derivative such as naphthol; a hydroxyalkylphenol such as p-hydroxyphenyl-2-ethanol, p-hydroxyphenyl-3-propanol and p-hydroxyphenyl-4-butanol; a hydroxyalkylcresol such as hydroxyethylcresol; Ethylene oxide adducts; alcoholic hydroxyl group-containing phenols such as bisphenol monopropylene oxide adducts Carboxyl derivatives such as p-hydroxyphenylacetic acid, p-hydroxyphenylpropionic acid, p-hydroxyphenylbutanoic acid, p-hydroxycinnamic acid, hydroxybenzoic acid, hydroxyphenylbenzoic acid, hydroxyphenoxybenzoic acid, diphenolic acid, etc. And group-containing phenol derivatives. Further, methylolated products of the above phenol derivatives such as bishydroxymethyl-p-cresol may be used as the phenol derivative.

  Furthermore, the phenol resin may be a condensation polymerization product of the above-described phenol derivative and a compound other than phenol such as m-xylene. In this case, the molar ratio of the compound other than phenol to the phenol derivative used for the condensation polymerization is preferably less than 0.5.

  Compounds other than the above-described phenol derivatives and phenol compounds are used singly or in combination of two or more.

  The aldehydes used to obtain the phenol resin include formaldehyde, acetaldehyde, furfural, benzaldehyde, hydroxybenzaldehyde, methoxybenzaldehyde, hydroxyphenylacetaldehyde, methoxyphenylacetaldehyde, crotonaldehyde, chloroacetaldehyde, chlorophenylacetaldehyde, acetone, glyceraldehyde, Glyoxylic acid, methyl glyoxylate, phenyl glyoxylate, hydroxyphenyl glyoxylate, formyl acetic acid, methyl formyl acetate, 2-formylpropionic acid, methyl 2-formylpropionate, pyruvic acid, repric acid, 4-acetylbutyric acid, acetone dicarboxylic acid Acid and 3,3′-4,4′-benzophenone tetracarboxylic acid And the like. In addition, a formaldehyde precursor such as paraformaldehyde or trioxane may be used in the reaction. These are used singly or in combination of two or more.

  Specific examples of phenol resins obtained from such phenol derivatives and aldehydes include phenol / formaldehyde novolak resin, cresol / formaldehyde novolak resin, xylylenol / formaldehyde novolak resin, resorcinol / formaldehyde novolak resin, phenol-naphthol / formaldehyde novolak. Examples thereof include resins.

(Poly (hydroxystyrene))
As poly (hydroxystyrene), for example, the ethylenically unsaturated double bond of hydroxystyrene introduced with a protecting group is polymerized (vinyl polymerization) in the presence of a catalyst (radical initiator) and further deprotected. What is obtained by this can be used. Further, branch type poly (hydroxystyrene) such as PHS-B (trade name of DuPont) may be used.

  Here, as the protective group for hydroxystyrene, conventionally known ones such as an alkyl group and a silyl group can be used. Further, styrene, (meth) acrylic acid ester, and the like can be copolymerized with hydroxystyrene having a protective group introduced.

  The molecular weight of the component (A) is preferably 1,000 to 500,000, and more preferably 2,000 to 200,000 in terms of weight average molecular weight in consideration of solubility in an aqueous alkali solution and balance between the photosensitive properties and the cured film properties. Here, the weight average molecular weight is a value obtained by measuring by a gel permeation chromatography method and converting from a standard polystyrene calibration curve.

<(B) component>
(B) The compound which produces | generates an acid by the light of a component is used as a photosensitive agent. Such a component (B) has a function of generating an acid by light irradiation and increasing the solubility of the irradiated portion in an alkaline aqueous solution. As the component (B), a compound generally called a photoacid generator can be used. Specific examples of the component (B) include o-quinonediazide compounds, aryldiazonium salts, diaryliodonium salts, and triarylsulfonium salts. Of these, o-quinonediazide compounds are preferred because of their high sensitivity.

  As the o-quinonediazide compound, for example, a compound obtained by subjecting o-quinonediazidesulfonyl chloride to a hydroxy compound, an amino compound or the like in the presence of a dehydrochlorinating agent can be used.

  Examples of the o-quinonediazidesulfonyl chloride used in the reaction include benzoquinone-1,2-diazide-4-sulfonyl chloride, naphthoquinone-1,2-diazide-5-sulfonyl chloride, and naphthoquinone-1,2-diazide-4- And sulfonyl chloride.

  Examples of the hydroxy compound used in the reaction include hydroquinone, resorcinol, pyrogallol, bisphenol A, bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 2,3,4- Trihydroxybenzophenone, 2,3,4,4′-tetrahydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,3,4,2 ′, 3′-pentahydroxybenzophenone, 2,3 , 4,3 ′, 4 ′, 5′-hexahydroxybenzophenone, bis (2,3,4-trihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) propane, 4b, 5,9b, 10-tetrahydro-1,3,6,8-tetrahydroxy-5,10-dimethyli De Bruno [2,1-a] indene, tris (4-hydroxyphenyl) methane, tris (4-hydroxyphenyl) ethane, and the like.

  Examples of the amino compound used in the reaction include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, and 4,4 ′. -Diaminodiphenyl sulfide, o-aminophenol, m-aminophenol, p-aminophenol, 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, Bis (3-amino-4-hydroxyphenyl) propane, bis (4-amino-3-hydroxyphenyl) propane, bis (3-amino-4-hydroxyphenyl) sulfone, bis (4-amino-3-hydroxyphenyl) Sulfone, bis (3-amino-4-hydroxypheny ) Hexafluoropropane, bis (4-amino-3-hydroxyphenyl) hexafluoropropane, and the like.

  Examples of the dehydrochlorination agent used in the reaction include sodium carbonate, sodium hydroxide, sodium hydrogen carbonate, potassium carbonate, potassium hydroxide, trimethylamine, triethylamine, pyridine and the like. Moreover, as a reaction solvent, dioxane, acetone, methyl ethyl ketone, tetrahydrofuran, diethyl ether, N-methylpyrrolidone, or the like is used.

  o-quinonediazidosulfonyl chloride and hydroxy compound and / or amino compound are blended so that the total number of moles of hydroxy group and amino group is 0.5 to 1 per mole of o-quinonediazidesulfonyl chloride. It is preferred that A preferred blending ratio of the dehydrochlorinating agent and o-quinonediazide sulfonyl chloride is in the range of 0.95 / 1 molar equivalent to 1 / 0.95 molar equivalent.

  In addition, the preferable reaction temperature of the above-mentioned reaction is 0-40 degreeC, and preferable reaction time is 1 to 10 hours.

  The blending amount of the component (B) is preferably 3 to 100 parts by weight with respect to 100 parts by weight of the component (A) from the viewpoint of the difference in dissolution rate between the exposed part and the unexposed part and the allowable width of sensitivity. 5 to 50 parts by weight is more preferable, and 5 to 30 parts by weight is most preferable.

<(C) component>
The elastomer of component (C) is used for imparting flexibility to the cured product of the positive photosensitive resin composition. Conventionally known elastomers can be used as the elastomer, but it is preferable that the polymer constituting the elastomer has a Tg of 20 ° C. or lower.

  Examples of such elastomers include styrene elastomers, olefin elastomers, urethane elastomers, polyester elastomers, polyamide elastomers, acrylic elastomers, and silicone elastomers. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of the styrenic elastomer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene block copolymer, and styrene-butadiene-methacrylate block. Examples thereof include polymers. As a component constituting the styrene-based elastomer, styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, and 4-cyclohexylstyrene can be used in addition to styrene.

  Specific examples of the styrene-based elastomer include Tufprene, Solprene T, Asaprene T, Tuftec (manufactured by Asahi Kasei Kogyo Co., Ltd.), Elastomer AR (manufactured by Aron Kasei Co., Ltd.), Kraton G, Califlex (manufactured by Shell Japan Co., Ltd.), JSR-TR, TSR-SIS, Dynalon (above, manufactured by JSR), Denka STR (manufactured by Denki Kagaku), Quintac (manufactured by Zeon Corporation), TPE-SB series (manufactured by Sumitomo Chemical), Lavalon (Mitsubishi Chemical) ), Septon, Hybler (above, Kuraray Co., Ltd.), Sumiflex (Sumitomo Bakelite Co., Ltd.), Rheostomer, Actimer (above, Riken Vinyl Kogyo Co., Ltd.), Paraloid EXL series (Rohm and Haas Co., Ltd.), etc. Can be mentioned.

  Examples of the olefin elastomer include copolymers of α-olefins having 2 to 20 carbon atoms (for example, ethylene-propylene copolymer (EPR), ethylene-propylene-diene copolymer (EPDM)), and carbon number 2 Copolymer of ~ 20 dienes and α-olefin, carboxy-modified NBR obtained by copolymerizing epoxidized polybutadienebutadiene-acrylonitrile copolymer with methacrylic acid, ethylene-α-olefin copolymer rubber, ethylene-α-olefin -Diene copolymer rubber, propylene-α-olefin copolymer rubber, butene-α-olefin copolymer rubber, and the like. Specific examples of the α-olefin having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-hexene and 4-methyl-1-pentene. Specific examples of the dienes having 2 to 20 carbon atoms Include dicyclopentadiene, 1,4-hexadiene, cyclooctanediene, methylene norbornene, ethylidene norbornene, butadiene, isoprene and the like.

  Specific examples of olefin elastomers include milastoma (Mitsui Petrochemical Co., Ltd.), EXACT (Exxon Chemical Co., Ltd.), ENGAGE (Dow Chemical Co., Ltd.), Nipol series (Nihon Zeon Co., Ltd.), hydrogenated styrene-butadiene rubber DYNABON. HSBR (manufactured by JSR), butadiene-acrylonitrile copolymer NBR series (manufactured by JSR), XER series (both terminal carboxyl group-modified butadiene-acrylonitrile copolymers having a crosslinking point (manufactured by JSR), partially polybutadiene Examples thereof include epoxidized epoxidized polybudadiene BF-1000 (manufactured by Nippon Soda Co., Ltd.), liquid butadiene-acrylonitrile copolymer HYCAR series (manufactured by Ube Industries, Ltd.), and the like.

  Urethane elastomers are composed of structural units of a hard segment composed of low molecular (short chain) diol and diisocyanate and a soft segment composed of high molecular (long chain) diol and diisocyanate. Examples of the polymer (long chain) diol include polypropylene glycol, polytetramethylene oxide, poly (1,4-butylene adipate), poly (ethylene-1,4-butylene adipate), polycaprolactone, and poly (1,6-hexene). Xylene carbonate), poly (1,6-hexylene-neopentylene adipate) and the like. The number average molecular weight of the polymer (long chain) diol is preferably 500 to 10,000. Examples of the low molecular (short chain) diol include ethylene glycol, propylene glycol, 1,4-butanediol, and bisphenol A. The number average molecular weight of the short-chain diol is preferably 48 to 500.

  Specific examples of the urethane-based elastomer include PANDEX T-2185, T-2983N (manufactured by Dainippon Ink & Chemicals, Inc.), sylactolan E790, and the Hitaroid series (manufactured by Hitachi Chemical Co., Ltd.).

  The polyester elastomer is obtained by polycondensation of a dicarboxylic acid or a derivative thereof and a diol compound or a derivative thereof. Specific examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and aromatic dicarboxylic acids in which hydrogen atoms of these aromatic rings are substituted with a methyl group, an ethyl group, a phenyl group, and the like, Examples thereof include aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid and dodecanedicarboxylic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. These compounds can be used alone or in combination of two or more. Specific examples of the diol compound include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, and 1,4-cyclohexanediol; Examples include alicyclic diol, bisphenol A, bis- (4-hydroxyphenyl) -methane, bis- (4-hydroxy-3-methylphenyl) -propane, resorcin and the like. These compounds can be used individually by 1 type or in combination of 2 or more types.

  In addition, a multi-block copolymer having an aromatic polyester (eg, polybutylene terephthalate) portion as a hard segment component and an aliphatic polyester (eg, polytetramethylene glycol) portion as a soft segment component is used as a polyester elastomer. You can also. Polyester elastomers are available in various grades depending on the types and ratios of hard segments and soft segments, and differences in molecular weight.

  Specific examples of polyester elastomers include Hytrel (Du Pont-Toray), Perprene (Toyobo), Espel (Hitachi Chemical Industries), and the like.

  Polyamide elastomers are composed of hard segments made of polyamide and soft segments made of polyether or polyester, and are roughly divided into two types: polyether block amide type and polyether ester block amide type. The Examples of the polyamide include polyamide 6, polyamide 11, and polyamide 12. Examples of the polyether include polyoxyethylene, polyoxypropylene, polytetramethylene glycol and the like.

  Specific examples of polyamide-based elastomers include UBE polyamide elastomer (manufactured by Ube Industries), Daiamide (manufactured by Daicel Huls), PEBAX (manufactured by Toray Industries, Inc.), Grilon ELY (manufactured by MMS Japan), Novamid (manufactured by Mitsubishi Chemical Corporation). ), Glase (Dainippon Ink Chemical Co., Ltd.) and the like.

  Acrylic elastomers are acrylic esters such as ethyl acrylate, butyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, monomers having an epoxy group such as glycidyl methacrylate, allyl glycidyl ether, and / or vinyls such as acrylonitrile and ethylene. It is obtained by copolymerizing with a monomer.

  Examples of such acrylic elastomers include acrylonitrile-butyl acrylate copolymer, acrylonitrile-butyl acrylate-ethyl acrylate copolymer, acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer, and the like.

  Silicone elastomers are mainly composed of organopolysiloxane, and are classified into polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane. Further, a part of organopolysiloxane modified with a vinyl group, an alkoxy group or the like may be used.

  Specific examples of such silicone elastomers include the KE series (manufactured by Shin-Etsu Chemical Co., Ltd.), SE series, CY series, SH series (manufactured by Toray Dow Corning Silicone Co., Ltd.) and the like.

  In addition to the above-described elastomer, a rubber-modified epoxy resin can also be used. The rubber-modified epoxy resin includes, for example, a part or all of epoxy groups such as bisphenol F type epoxy resin, bisphenol A type epoxy resin, salicylaldehyde type epoxy resin, phenol novolac type epoxy resin, or cresol novolac type epoxy resin, It is obtained by modifying with a terminal carboxylic acid-modified butadiene-acrylonitrile rubber, a terminal amino-modified silicone rubber or the like.

  The component (C) may be a fine particle elastomer (hereinafter also referred to as “elastomer fine particles”). The elastomer fine particles are elastomers dispersed in a fine particle state in a positive photosensitive resin composition, and include elastomers that are islands in a sea-island structure by phase separation in an incompatible system, elastomers that are so-called microdomains, and the like. Is.

  The elastomer fine particles are obtained by copolymerizing a crosslinkable monomer having two or more unsaturated polymerizable groups and one or more other monomers selected so that the Tg of the elastomer fine particles is 20 ° C. or less (so-called cross-linking). Fine particles) are preferred. As other monomers, those obtained by copolymerizing monomers having a functional group other than a polymerizable group, for example, a functional group such as a carboxyl group, an epoxy group, an amino group, an isocyanato group, and a hydroxyl group are preferably used.

  Examples of the crosslinkable monomer include divinylbenzene, diallyl phthalate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, polyethylene glycol di Examples thereof include compounds having a plurality of polymerizable unsaturated groups such as (meth) acrylate and polypropylene glycol di (meth) acrylate. Of these, divinylbenzene is preferred.

  The crosslinkable monomer used for producing the elastomer fine particles is preferably used in an amount of 1 to 20% by weight, more preferably 2 to 10% by weight, based on the total monomers used for copolymerization.

  Examples of other monomers include diene compounds such as butadiene, isoprene, dimethylbutadiene, chloroprene, and 1,3-pentadiene; (meth) acrylonitrile, α-chloroacrylonitrile, α-chloromethylacrylonitrile, α-methoxyacrylonitrile, α- Unsaturated nitrile compounds such as ethoxyacrylonitrile, crotonic acid nitrile, cinnamic acid nitrile, itaconic acid dinitrile, maleic acid dinitrile, and fumaric acid dinitrile; (meth) acrylamide, N, N′-methylenebis (meth) acrylamide, N, N '-Ethylenebis (meth) acrylamide, N, N'-hexamethylenebis (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide Unsaturated amides such as N, N-bis (2-hydroxyethyl) (meth) acrylamide, crotonic acid amide, cinnamic acid amide; methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid (Meth) acrylic esters such as propyl, butyl (meth) acrylate, hexyl (meth) acrylate, lauryl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate; styrene, α- Aromatic vinyl compounds such as methylstyrene, o-methoxystyrene, p-hydroxystyrene, p-isopropenylphenol; diglycidyl ether of bisphenol A, diglycidyl ether of glycol, (meth) acrylic acid, hydroxyalkyl (meta ) With acrylate etc. Epoxy (meth) acrylate obtained by reaction; urethane (meth) acrylates obtained by reaction of hydroxyalkyl (meth) acrylate and polyisocyanate; containing epoxy groups such as glycidyl (meth) acrylate and (meth) allyl glycidyl ether Unsaturated compounds; (meth) acrylic acid, itaconic acid, succinic acid-β- (meth) acryloxyethyl, maleic acid-β- (meth) acryloxyethyl, phthalic acid-β- (meth) acryloxyethyl, hexa Unsaturated acid compounds such as hydrophthalic acid-β- (meth) acryloxyethyl; Amino group-containing unsaturated compounds such as dimethylamino (meth) acrylate and diethylamino (meth) acrylate; (meth) acrylamide, dimethyl (meth) acrylamide Desaturation containing amide groups such as Examples thereof include hydroxyl group-containing unsaturated compounds such as compounds, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate.

  Among these, butadiene, isoprene, (meth) acrylonitrile, (meth) acrylic acid alkyl esters, styrene, p-hydroxystyrene, p-isopropenylphenol, glycidyl (meth) acrylate, (meth) acrylic acid, hydroxyalkyl (Meth) acrylates and the like are preferably used.

  As such other monomers, it is preferable to use at least one diene compound, specifically, butadiene. Such a diene compound is preferably used in an amount of 20 to 80% by weight, more preferably 30 to 70% by weight, based on all monomers used for copolymerization. By using the diene compound at such a ratio, the elastomer fine particles become rubber-like soft fine particles, and in particular, it is possible to prevent cracks from occurring in the obtained cured film and to obtain a cured film having excellent durability. it can.

  The average particle diameter of the elastomer fine particles is preferably 30 to 500 nm, more preferably 40 to 200 nm, and still more preferably 50 to 120 nm. The method for controlling the particle size of the elastomer fine particles is not particularly limited. For example, when the elastomer fine particles are synthesized by emulsion polymerization, the number of micelles during the emulsion polymerization is controlled by the amount of the emulsifier to be used. Can be controlled.

  The amount of such component (C) is preferably 1 to 50 parts by weight, more preferably 5 to 30 parts by weight per 100 parts by weight of component (A). If the amount of the elastomer blended is less than 1 part by weight, the thermal shock resistance of the resulting cured film tends to decrease, and if it exceeds 50 parts by weight, the resolution and the heat resistance of the cured film to be obtained may decrease. There is a tendency for the compatibility and dispersibility to decrease.

<(D) component>
The low molecular weight compound having a phenolic hydroxyl group as component (D) is used for increasing the dissolution rate of the exposed area when developing with an alkaline aqueous solution and improving the sensitivity. Furthermore, by containing the component (D), when the photosensitive resin film after pattern formation is heated and cured, the component (D) reacts with the component (A) to form a bridge structure. Thereby, brittleness of the film and melting of the film can be prevented.

  The molecular weight of such a low molecular compound having a phenolic hydroxyl group is preferably 2000 or less. In consideration of the solubility in an aqueous alkali solution and the balance between the photosensitive properties and the physical properties of the cured film, the number average molecular weight is preferably 94 to 2000, more preferably 108 to 2000, and most preferably 108 to 1500.

  As the low molecular weight compound having a phenolic hydroxyl group, conventionally known compounds can be used, but the compound represented by the following general formula (I) is effective in promoting the dissolution of the exposed area and curing the photosensitive resin film. It is particularly preferred because of its excellent balance of effects for preventing melting.

In formula (I), X represents a single bond or a divalent organic group, R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom or a monovalent organic group, and s and t are each Independently represents an integer of 1 to 3, and u and v each independently represent an integer of 0 to 4.

  In general formula (I), the compound in which X is a single bond is a biphenol (dihydroxybiphenyl) derivative. Examples of the divalent organic group represented by X include alkylene groups having 1 to 10 carbon atoms such as methylene group, ethylene group and propylene group, alkylidene groups having 2 to 10 carbon atoms such as ethylidene group, and phenylene groups. Arylene groups having 6 to 30 carbon atoms, such as groups in which some or all of the hydrogen atoms of these hydrocarbon groups are substituted with halogen atoms such as fluorine atoms, sulfone groups, carbonyl groups, ether bonds, thioether bonds, amide bonds Etc. Among these, a divalent organic group represented by the following general formula (II) is preferable.

  In the formula (II), X ′ is a single bond, an alkylene group (for example, an alkylene group having 1 to 10 carbon atoms), an alkylidene group (for example, an alkylidene group having 2 to 10 carbon atoms), or one of these hydrogen atoms. A group, a sulfone group, a carbonyl group, an oxy group, a thio group, or an amide group, part or all of which is substituted with a halogen atom; R ″ represents a hydrogen atom, a hydroxy group, an alkyl group, or a haloalkyl group; Represents an integer of -10, and a plurality of R ″ may be the same or different from each other.

  The blending amount of the component (D) is preferably 1 to 50 parts by weight with respect to 100 parts by weight of the component (A) from the viewpoints of the development time, the allowable width of the unexposed part remaining film ratio, and the characteristics of the cured film. 2 to 30 parts by weight is more preferable, and 3 to 25 parts by weight is most preferable.

<(E) component>
(E) A component is a solvent. Specific examples thereof include γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether acetate, benzyl acetate, n-butyl acetate, ethoxyethyl propionate, 3-methylmethoxypropionate, N-methyl-2-pyrrolidone, N , N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphorylamide, tetramethylene sulfone, diethyl ketone, diisobutyl ketone, methyl amyl ketone, cyclohexanone, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol Examples thereof include monobutyl ether and dipropylene glycol monomethyl ether.

  These solvents can be used alone or in combination of two or more. Moreover, the compounding quantity of (C) component is although it does not specifically limit, It is preferable to adjust so that the ratio of the solvent in a positive type photosensitive resin composition may be 20 to 90 weight%.

<(F) component>
In addition to the components (A) to (E), the positive photosensitive resin composition described above may further contain (F) a compound that generates an acid by heating. By using the component (F), it is possible to generate an acid when the photosensitive resin film is heated, and the reaction between the component (A) and the component (D), that is, the thermal crosslinking reaction is promoted, and the cured film The heat resistance of is improved. In addition, since the component (F) generates an acid even when irradiated with light, the solubility of the exposed portion in the alkaline aqueous solution increases. Therefore, the difference in solubility in the alkaline aqueous solution between the unexposed area and the exposed area is further increased, and the resolution is improved.

  It is preferable that such (F) component produces | generates an acid by heating to 50-250 degreeC, for example. Specific examples of the component (F) include salts formed from strong acids such as onium salts and bases, and imide sulfonates.

  Examples of the onium salt include diaryliodonium salts such as aryldiazonium salts and diphenyliodonium salts; diaryliodonium salts and di (alkylaryl) iodonium salts such as di (t-butylphenyl) iodonium salts; trimethylsulfonium salts and the like. A trialkylsulfonium salt; a dialkylmonoarylsulfonium salt such as dimethylphenylsulfonium salt; a diarylmonoalkyliodonium salt such as diphenylmethylsulfonium salt; and a triarylsulfonium salt. Among these, di (t-butylphenyl) iodonium salt of paratoluenesulfonic acid, di (t-butylphenyl) iodonium salt of trifluoromethanesulfonic acid, trimethylsulfonium salt of trifluoromethanesulfonic acid, dimethyl of trifluoromethanesulfonic acid Phenylsulfonium salt, diphenylmethylsulfonium salt of trifluoromethanesulfonic acid, di (t-butylphenyl) iodonium salt of nonafluorobutanesulfonic acid, diphenyliodonium salt of camphorsulfonic acid, diphenyliodonium salt of ethanesulfonic acid, benzenesulfonic acid Dimethylphenylsulfonium salt and diphenylmethylsulfonium salt of toluenesulfonic acid are preferred.

  Moreover, as a salt formed from a strong acid and a base, the salt formed from the following strong acids and a base other than the above-mentioned onium salt, for example, a pyridinium salt can also be used. Strong acids include p-toluenesulfonic acid, arylsulfonic acid such as benzenesulfonic acid, camphorsulfonic acid, trifluoromethanesulfonic acid, perfluoroalkylsulfonic acid such as nonafluorobutanesulfonic acid, methanesulfonic acid, ethanesulfonic acid And alkylsulfonic acids such as butanesulfonic acid. Examples of the base include pyridine, alkylpyridines such as 2,4,6-trimethylpyridine, N-alkylpyridines such as 2-chloro-N-methylpyridine, and halogenated-N-alkylpyridines.

  As the imide sulfonate, for example, naphthoyl imide sulfonate or phthalimide sulfonate can be used.

As the component (F), a compound having a structure represented by the following general formula (III) or a compound having a sulfonamide structure represented by the following general formula (IV) can be used in addition to the above-described compounds. .
R ⁵ R ⁶ C═N—O—SO ₂ —R ⁷ (III)
—NH—SO ₂ —R ⁸ (IV)

In formula (III), R ⁵ is, for example, a cyano group, and R ⁶ is, for example, a methoxyphenyl group, a phenyl group, or the like. R ⁷ is, for example, an aryl group such as p-methylphenyl group or phenyl group, an alkyl group such as methyl group, ethyl group or isopropyl group, or a perfluoroalkyl group such as trifluoromethyl group or nonafluorobutyl group. is there.

R ⁸ is, for example, an alkyl group such as a methyl group, an ethyl group or a propyl group, an aryl group such as a methylphenyl group or a phenyl group, a perfluoroalkyl group such as a trifluoromethyl group or nonafluorobutyl. Examples of the group bonded to the N atom of the sulfonamide structure represented by the general formula (IV) include 2,2′-bis (4-hydroxyphenyl) hexafluoropropane and 2,2′-bis (4-hydroxy). Phenyl) propane, di (4-hydroxyphenyl) ether.

  (F) As for the compounding quantity of component, 0.1-30 weight part is preferable with respect to 100 weight part of (A) component, 0.2-20 weight part is more preferable, 0.5-10 weight part is further preferable.

  In addition to the above components (A) to (F), the positive photosensitive resin composition described above includes (1) a compound having an epoxy group, (2) a dissolution accelerator, (3) a dissolution inhibitor, (4) You may further contain components, such as a coupling agent and (5) surfactant or a leveling agent.

<(1) Compound having epoxy group>
By blending a compound having an epoxy group with the above-mentioned positive photosensitive resin, when the photosensitive resin film after pattern formation is heated and cured, it reacts with the component (A) to form a bridge structure. Thereby, brittleness of the film and melting of the film can be prevented. A conventionally well-known thing can be used as a compound which has an epoxy group. Specific examples thereof include bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, alicyclic epoxy resin, glycidyl amine, heterocyclic epoxy, and polyalkylene glycol diglycidyl ether.

  When blending such a compound having an epoxy group, the blending amount is preferably 1 to 30 parts by weight with respect to 100 parts by weight of component (A) from the viewpoint of solubility in an aqueous alkali solution and physical properties of the cured film. 3 to 25 parts by weight is more preferable.

<(2) Dissolution promoter>
By adding a dissolution accelerator to the positive photosensitive resin described above, as in the case of the component (D), the dissolution rate of the exposed area when developing with an aqueous alkaline solution is increased, and the sensitivity and resolution are improved. be able to. A conventionally well-known thing can be used as a dissolution promoter. Specific examples thereof include compounds having a carboxyl group, a sulfonic acid, and a sulfonamide group.

  When such a dissolution accelerator is blended, the blending amount can be determined by the dissolution rate with respect to the alkaline aqueous solution, for example, 0.01 to 30 parts by weight with respect to 100 parts by weight of component (A). be able to.

<(3) Dissolution inhibitor>
A dissolution inhibitor is a compound that inhibits the solubility of the component (A) in an alkaline aqueous solution, and is used to control the remaining film thickness, development time, and contrast. Specific examples thereof include diphenyliodonium nitrate, bis (p-tert-butylphenyl) iodonium nitrate, diphenyliodonium bromide, diphenyliodonium chloride, diphenyliodonium iodide and the like. When blending a dissolution inhibitor, the blending amount is preferably 0.01 to 20 parts by weight, preferably 0.01 to 15 parts per 100 parts by weight of component (A), from the viewpoints of sensitivity and allowable width of development time. Part by weight is more preferred, and 0.05 to 10 parts by weight is even more preferred.

<(4) Coupling agent>
By mix | blending a coupling agent with the above-mentioned positive photosensitive compound, the adhesiveness with the board | substrate of the cured film formed can be improved. Examples of the coupling agent include organic silane compounds and aluminum chelate compounds.

  Examples of the organic silane compound include vinyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, urea propyltriethoxysilane, methylphenylsilanediol, ethylphenylsilanediol, n- Propylphenylsilanediol, isopropylphenylsilanediol, n-butylsiphenylsilanediol, isobutylphenylsilanediol, tert-butylphenylsilanediol, diphenylsilanediol, ethylmethylphenylsilanol, n-propylmethylphenylsilanol, isopropylmethylphenylsilanol , N-butylmethylphenylsilanol, isobutylmethylphenylsilanol, tert-butylmethylphenylsilanol , Ethyl n-propylphenylsilanol, ethylisopropylphenylsilanol, n-butylethylphenylsilanol, isobutylethylphenylsilanol, tert-butylethylphenylsilanol, methyldiphenylsilanol, ethyldiphenylsilanol, n-propyldiphenylsilanol, isopropyldiphenylsilanol , N-butyldiphenylsilanol, isobutyldiphenylsilanol, tert-butyldiphenylsilanol, phenylsilanetriol, 1,4-bis (trihydroxysilyl) benzene, 1,4-bis (methyldihydroxysilyl) benzene, 1,4-bis (Ethyldihydroxysilyl) benzene, 1,4-bis (propyldihydroxysilyl) benzene, 1,4-bis (butyldi) Droxysilyl) benzene, 1,4-bis (dimethylhydroxysilyl) benzene, 1,4-bis (diethylhydroxysilyl) benzene, 1,4-bis (dipropyldroxysilyl) benzene, 1,4-bis (dibutylhydroxy) And silyl) benzene.

  In the case of using such a coupling agent, the blending amount is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of component (A).

<(5) Surfactant or leveling agent>
By blending a surfactant or a leveling agent with the above-mentioned positive photosensitive compound, coatability, for example, striation (film thickness unevenness) can be prevented, and developability can be improved. Examples of such surfactants or leveling agents include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, and the like, and Megafax F171 is a commercially available product. F173, R-08 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.), Florard FC430, FC431 (trade name, Sumitomo 3M), organosiloxane polymers KP341, KBM303, KBM403, KBM803 (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) ) And the like.

  In the case of using such a surfactant or leveling agent, the total blending amount is preferably 0.001 to 5 parts by weight, and 0.01 to 3 parts by weight with respect to 100 parts by weight of component (A). More preferred.

  The positive photosensitive resin composition described above can be developed using an aqueous alkaline solution such as tetramethylammonium hydroxide (TMAH). Furthermore, by using the above-mentioned positive photosensitive resin composition, it is possible to form a resist pattern having a good shape having good adhesion and heat resistance with sufficiently high sensitivity and resolution.

[Method for producing resist pattern]
Next, a method for producing a resist pattern will be described. The method for producing a resist pattern of the present invention comprises a step of exposing a photosensitive resin film comprising the above-described positive photosensitive resin composition, and a step of patterning the exposed photosensitive resin film by developing with an aqueous alkali solution. Heating the patterned photosensitive resin film. Hereinafter, each step will be described.

(Coating / drying (film formation) process)
First, the positive photosensitive resin composition described above is applied onto a support substrate and dried to form a photosensitive resin film. In this step, first, the positive photosensitive resin composition described above is used on a support substrate such as a glass substrate, a semiconductor, a metal oxide insulator (eg, TiO ₂ , SiO ₂ ), or silicon nitride, using a spinner or the like. And spin coat to form a coating film. The support substrate on which the coating film has been formed is dried using a hot plate, oven, or the like. Thereby, a photosensitive resin film is formed on the support substrate.

(Exposure process)
Next, in the exposure step, the photosensitive resin film formed on the support substrate is irradiated with actinic rays such as ultraviolet rays, visible rays, and radiations through a mask. In the positive photosensitive resin composition described above, the component (A) is highly transparent to i-line, so i-line irradiation can be suitably used. In addition, after exposure, post-exposure heating (PEB) can be performed as necessary. The post-exposure heating temperature is preferably 70 ° C. to 140 ° C., and the post-exposure heating time is preferably 1 minute to 5 minutes.

(Development process)
In the development process, the photosensitive resin film is patterned by removing the exposed portion of the photosensitive resin film after the exposure process with a developer. As the developer, for example, an alkaline aqueous solution such as sodium hydroxide, potassium hydroxide, sodium silicate, ammonia, ethylamine, diethylamine, triethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH) is preferably used. The base concentration of these aqueous solutions is preferably 0.1 to 10% by weight. Furthermore, alcohols and surfactants can be added to the developer and used. Each of these can be blended in the range of preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the developer.

(Heat treatment process)
Next, in the heat treatment step, the patterned photosensitive resin film is subjected to heat treatment, whereby a resist pattern made of the photosensitive resin film after heating can be formed. The heating temperature in the heat treatment step is desirably 250 ° C. or less, more desirably 225 ° C. or less, and further desirably 140 to 200 ° C. from the viewpoint of sufficiently preventing damage to the electronic device due to heat.

  The heat treatment can be performed using an oven such as a quartz tube furnace, a hot plate, rapid thermal annealing, a vertical diffusion furnace, an infrared curing furnace, an electron beam curing furnace, and a microwave curing furnace. In addition, either air or an inert atmosphere such as nitrogen can be selected. However, it is preferable to perform the process under nitrogen because the oxidation of the pattern can be prevented. Since the above-mentioned desirable heating temperature range is lower than the conventional heating temperature, damage to the support substrate and the electronic device can be suppressed to a small level. Therefore, by using the resist pattern manufacturing method of the present invention, electronic devices can be manufactured with high yield. It also leads to energy savings in the process. Furthermore, according to the positive photosensitive resin composition of the present invention, since the volume shrinkage (curing shrinkage) in the heat treatment step found in photosensitive polyimide and the like is small, it is possible to prevent a reduction in dimensional accuracy.

  The heat treatment time in the heat treatment step may be a time sufficient for the positive photosensitive resin composition to cure, but is preferably about 5 hours or less in view of work efficiency.

  The heat treatment can be performed using a microwave curing device or a variable frequency microwave curing device in addition to the above-described oven. By using these apparatuses, it is possible to effectively heat only the photosensitive resin film while keeping the temperature of the substrate and the electronic device at, for example, 200 ° C. or lower.

  In the variable frequency microwave curing apparatus, the microwave is irradiated in pulses while changing its frequency, so that standing waves can be prevented and the substrate surface can be heated uniformly. In addition, when a metal wiring is included as an electronic component to be described later as a substrate, the occurrence of discharge from the metal can be prevented by irradiating microwaves in a pulsed manner while changing the frequency, and the electronic component is protected from destruction. This is preferable. Furthermore, it is preferable to heat using a frequency-variable microwave because the cured film properties do not deteriorate even when the curing temperature is lowered as compared with the case of using an oven (J. Photopolym. Sci. Technol., 18, 327-332 (2005). )reference).

  The frequency of the frequency variable microwave is in the range of 0.5 to 20 GHz, but is practically preferably in the range of 1 to 10 GHz, and more preferably in the range of 2 to 9 GHz. In addition, it is desirable to continuously change the frequency of the microwave to be irradiated, but actually the irradiation is performed by changing the frequency stepwise. At that time, the shorter the time for irradiating a single-frequency microwave, the less likely it is to generate a standing wave or a metal discharge. Therefore, the irradiation time is preferably 1 millisecond or less, particularly preferably 100 microseconds or less.

  The output of the microwave to be irradiated varies depending on the size of the apparatus and the amount of the object to be heated, but is generally in the range of 10 to 2000 W, practically preferably 100 to 1000 W, more preferably 100 to 700 W, further preferably 100 to 700 W. 500 W is most preferred. If the output is 10 W or less, it is difficult to heat the object to be heated in a short time, and if it is 2000 W or more, a rapid temperature rise tends to occur.

  Moreover, it is preferable to irradiate the microwave by turning it on / off in a pulsed manner. By irradiating the microwaves in a pulsed manner, it is preferable in that the set heating temperature can be maintained and damage to the cured film and the substrate can be avoided. Although the time for irradiating the pulsed microwave at one time varies depending on the conditions, it is preferably about 10 seconds or less.

  According to the method for producing a resist pattern as described above, a resist pattern having good heat resistance can be obtained with sufficiently high sensitivity and resolution.

[Semiconductor device manufacturing process]
Next, as an example of the resist pattern manufacturing method of the present invention, a semiconductor device manufacturing process will be described with reference to the drawings. 1 to 5 are schematic sectional views showing an embodiment of a manufacturing process of a semiconductor device having a multilayer wiring structure.

  First, the structure 100 shown in FIG. 1 is prepared. The structure 100 includes a semiconductor substrate 1 such as an Si substrate having circuit elements, a protective film 2 such as a silicon oxide film covering the semiconductor substrate 1 having a predetermined pattern from which the circuit elements are exposed, and on the exposed circuit elements. And the interlayer insulating film 4 made of a polyimide resin or the like formed on the protective film 2 and the first conductor layer 3 by a spin coating method or the like.

  Next, by forming the photosensitive resin layer 5 having the window portion 6A on the interlayer insulating film 4, the structure 200 shown in FIG. 2 is obtained. The photosensitive resin layer 5 is formed, for example, by applying a photosensitive resin such as chlorinated rubber, phenol novolac, polyhydroxystyrene, or polyacrylate ester by a spin coating method. The window portion 6A is formed so that a predetermined portion of the interlayer insulating film 4 is exposed by a known photolithography technique.

  After the interlayer insulating film 4 is etched to form the window 6B, the photosensitive resin layer 5 is removed to obtain a structure 300 shown in FIG. For etching the interlayer insulating film 4, dry etching means using a gas such as oxygen or carbon tetrafluoride can be used. By this etching, the portion of the interlayer insulating film 4 corresponding to the window portion 6A is selectively removed, and the interlayer insulating film 4 provided with the window portion 6B so that the first conductor layer 3 is exposed is obtained. Next, the photosensitive resin layer 5 is removed using an etching solution that corrodes only the photosensitive resin layer 5 without corroding the first conductor layer 3 exposed from the window 6B.

  Furthermore, the 2nd conductor layer 7 is formed in the part corresponding to the window part 6B, and the structure 400 shown in FIG. 4 is obtained. A known photolithography technique can be used to form the second conductor layer 7. As a result, the second conductor layer 7 and the first conductor layer 3 are electrically connected.

  Finally, the surface protective layer 8 is formed on the interlayer insulating film 4 and the second conductor layer 7 to obtain the semiconductor device 500 shown in FIG. In the present embodiment, the surface protective layer 8 is formed as follows. First, the positive photosensitive resin composition according to the above-described embodiment is applied onto the interlayer insulating film 4 and the second conductor layer 7 by spin coating, and dried to form a photosensitive resin film. Next, after light irradiation through a mask on which a pattern corresponding to the window 6C is drawn at a predetermined portion, the photosensitive resin film is patterned by developing with an alkaline aqueous solution. Thereafter, the photosensitive resin curtain is cured by heating to form a film as the surface protective layer 8. The surface protective layer 8 protects the first conductor layer 3 and the second conductor layer 7 from external stress, α rays, and the like, and the obtained semiconductor device 500 is excellent in reliability.

  In the above-described embodiment, the method for manufacturing a semiconductor device having a two-layer wiring structure is shown. However, when a multilayer wiring structure having three or more layers is formed, the above steps are repeated to form each layer. Can do. That is, it is possible to form a multilayer pattern by repeating each step of forming the interlayer insulating film 4 and each step of forming the surface protective layer 8. In the above example, not only the surface protective layer 8 but also the interlayer insulating film 4 can be formed using the positive photosensitive resin composition of the present invention.

[Electronic parts]
Next, the electronic component of the present invention will be described. The electronic component of the present invention has a resist pattern formed by the above-described manufacturing method as an interlayer insulating film or a surface protective layer. Here, the electronic component includes a semiconductor device, a multilayer wiring board, various electronic devices, and the like. The resist pattern can be used specifically as a surface protective layer or an interlayer insulating film of a semiconductor device, an interlayer insulating film of a multilayer wiring board, or the like. The electronic component of the present invention is not particularly limited except that it has a surface protective layer and an interlayer insulating film formed using the above-described positive photosensitive resin composition, and can have various structures.

  Moreover, since the above-mentioned positive photosensitive resin composition is excellent in stress relaxation property, adhesiveness, etc., it can also be used as various structural materials in packages having various structures developed in recent years. 6 and 7 show a cross-sectional structure of an example of such a semiconductor device.

  FIG. 6 is a schematic cross-sectional view showing a wiring structure as an embodiment of the semiconductor device. The semiconductor device 600 shown in FIG. 6 includes a silicon chip 23, an interlayer insulating film 11 provided on one surface side of the silicon chip 23, and an Al having a pattern including the pad portion 15 formed on the interlayer insulating film 11. A wiring layer 12, an insulating layer 13 (for example, a P-SiN layer) and a surface protective layer 14, which are sequentially stacked on the interlayer insulating film 11 and the Al wiring layer 12 while forming an opening on the pad portion 15, and a surface protective layer 14 in contact with the pad portion 15 in the openings of the insulating layer 13 and the surface protective layer 14 and the surface of the core 18 opposite to the surface protective layer 14. And a rewiring layer 16 extending on the surface protective layer 14. Further, the semiconductor device 600 is formed so as to cover the surface protective layer 14, the core 18, and the rewiring layer 16, and a cover coat layer 19 in which an opening is formed in a portion of the rewiring layer 16 on the core 18. The conductive ball 17 connected to the rewiring layer 16 with the barrier metal 20 interposed therebetween in the opening of the layer 19, the collar 21 that holds the conductive ball, and the cover coat layer 19 around the conductive ball 17 are provided. The underfill 22 is provided. The conductive ball 17 is used as an external connection terminal and is formed of solder, gold or the like. The underfill 22 is provided to relieve stress when the semiconductor device 600 is mounted.

  FIG. 7 is a schematic cross-sectional view showing a wiring structure as one embodiment of a semiconductor device. In the semiconductor device 700 of FIG. 7, an Al wiring layer (not shown) and a pad portion 15 of the Al wiring layer are formed on the silicon chip 23, and an insulating layer 13 is formed on the Al wiring layer. A surface protective layer 14 is formed. A rewiring layer 16 is formed on the pad portion 15, and the rewiring layer 16 extends to an upper portion of the connection portion 24 with the conductive ball 17. Further, a cover coat layer 19 is formed on the surface protective layer 14. The rewiring layer 16 is connected to the conductive ball 17 through the barrier metal 20.

  6 and 7, the positive photosensitive resin composition described above includes not only the interlayer insulating layer 11 and the surface protective layer 14 but also the cover coat layer 19, the core 18, the collar 21, the underfill 22, and the like. It can be used as a material for forming. The cured body using the positive photosensitive resin composition described above is excellent in adhesion with a metal layer such as the Al wiring layer 12 and the rewiring layer 16 and a sealing agent, and has a high stress relaxation effect. A semiconductor device in which the body is used for the cover coat layer 19, the core 18, the collar 21 such as solder, the underfill 12 used in a flip chip or the like has extremely high reliability.

  As described above, by using the positive photosensitive resin composition described above, curing using low-temperature heating of 200 ° C. or lower is possible in the heat treatment step that conventionally required 300 ° C. or higher. . Furthermore, since the positive photosensitive resin composition of the present invention has a small volume shrinkage (curing shrinkage) in the heat treatment step found in photosensitive polyimide and the like, it can prevent a reduction in dimensional accuracy. The cured film of the positive photosensitive resin composition has a high glass transition temperature. Accordingly, the surface protective layer is excellent in heat resistance. As a result, an electronic component such as a semiconductor device having excellent reliability can be obtained with high yield and high yield.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to these examples.

(Synthesis Example: Synthesis of Alkaline Aqueous Soluble Polymer (A3))
In a 0.5 liter flask equipped with a stirrer and a thermometer, 15.48 g of 4,4′-diphenyl ether dicarboxylic acid and 90 g of N-methylpyrrolidone were charged. After cooling to 5 ° C., 12.64 g of thionyl chloride was added dropwise and reacted for 30 minutes to obtain a solution (1) of 4,4′-diphenyl ether tetracarboxylic acid chloride. Next, 87.50 g of N-methylpyrrolidone was charged into a 0.5 liter flask equipped with a stirrer and a thermometer, and 2,2-bis (3-amino-4-hydroxyphenyl) -1,1,1, 18.30 g of 3,3,3-hexafluoropropane was added. After stirring and dissolving this, 8.53 g of pyridine was added, and while maintaining the temperature at 0 to 5 ° C., the solution (4) of 4,4′-diphenyl ether dicarboxylic acid chloride was added dropwise over 30 minutes, and then 30 minutes. Stirring was continued. The solution was poured into 3 liters of water, and the precipitate was collected, washed three times with pure water, and then dried under reduced pressure to obtain polyhydroxyamide (polybenzoxazole precursor) (hereinafter referred to as “A3”). . The weight-average molecular weight determined by GPC standard polystyrene conversion of A3 was 14600, and the degree of dispersion was 1.6.

(Comparative Synthesis Example 1: Synthesis of polyamic acid (α1))
In a 0.5 liter flask equipped with a stirrer and a thermometer, 4.00 g of 4,4′-diaminodiphenyl ether was placed and dissolved in 16.68 g of sufficiently dehydrated N, N-dimethylacetamide. 8.88 g of bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride was gradually added. Then, it stirred at room temperature (25 degreeC) for 24 hours, and obtained the solution of the polyamic acid ((alpha) 1).

(Comparative Synthesis Example 2: Synthesis of polyamic acid (α2))
In a 0.5 liter flask equipped with a stirrer and a thermometer, 4.00 g of 4,4′-diaminodiphenyl ether was placed, dissolved in 16.68 g of sufficiently dehydrated N, N-dimethylacetamide, and pyromellitic anhydride 4.36 g of product was gradually added. Then, it stirred at room temperature (25 degreeC) for 24 hours, and obtained the solution of the polyamic acid ((alpha) 2).

<Preparation of positive photosensitive resin composition>
The following A1, A2, and A3 were prepared as the component (A).
A1: m-cresol / p-cresol = 60/40 (molar ratio) cresol novolak resin (polystyrene equivalent weight average molecular weight = 7000, trade name EP4050G manufactured by Asahi Organic Materials Co., Ltd.)
A2: 4-hydroxystyrene / methyl methacrylate = 50/50 (molar ratio) copolymer (weight average molecular weight in terms of polystyrene = 10000, trade name Maruka Linker CMM manufactured by Maruzen Petrochemical Co., Ltd.)
A3: Polymer synthesized in the above synthesis example

The following B1 was prepared as the component (B).
B1: 1-naphthoquinone-2-diazide-5-sulfonic acid of 1,1-bis (4-hydroxyphenyl) -1- [4- {1- (4-hydroxyphenyl) -1-methylethyl} phenyl] ethane Ester (Esterification rate of about 90%, trade name TPPA528 manufactured by AZ Electronic Materials)

As the component (C), the following C1, C2, and C3 were prepared.
C1: Modified acrylonitrile-butadiene copolymer (Zeon Corporation product name Nipol SX1503A solvent extract)
C2: Butadiene-styrene-methacrylate copolymer (Rohm and Haas product name Paraloid EXL2655)
C3: Liquid butadiene-acrylonitrile copolymer (Ube Industries, Ltd. trade name HYCAR CTBNX-1300)

As the component (D), the following D1 and D2 were prepared.
D1: 2,2-bis {3,5-bis (hydroxymethyl) -4-hydroxyphenyl} -1,1,1,3,3,3-hexafluoropropane (trade name TML-BPAF manufactured by Honshu Chemical Industry Co., Ltd.) )
D2: 1,1-bis {3,5-bis (methoxymethyl) -4-hydroxyphenyl} methane (trade name TMOM-pp-BPF manufactured by Honshu Chemical Industry Co., Ltd.)

As the component (E), the following E1 and E2 were prepared.
E1: Mixture of γ-butyrolactone and propylene glycol monomethyl ether acetate (weight ratio 90/10)
E2: Ethyl lactate

The following F1 was prepared as the component (F).
F1: Di (t-butylphenyl) iodonium-p-toluenesulfonate (trade name BBI-201, manufactured by Midori Chemical Co., Ltd.)

The following α1, α2, β1, δ1, and ε1 were prepared as comparative compounds.
α1: Polyamic acid α2 synthesized in Comparative Synthesis Example 1 above: Polyamic acid synthesized in Comparative Synthesis Example 2 β1: Methacrylic acid 2-dimethylaminoethyl ester (1 equivalent to the carboxyl group of α2) as a photocrosslinking agent 60.9% by weight), 0.5 equivalent (38.4% by weight) of adipic acid divinyl ester as a photocrosslinking aid, and 2-benzyl-2-dimethylamino-4′- as a photopolymerization initiator. Mixture of morpholinobyrophenone (1 to 7% by weight) δ1: Hexamethoxymethylmelamine (CYTEC company name CYMEL300)
ε1: N, N-dimethylacetamide

(Examples 1-7)
(A)-(F) component was mix | blended in the predetermined | prescribed ratio shown in Table 1, and also 2 weight part of 50% methanol solutions of urea propyltriethoxysilane were mix | blended as a coupling agent. This solution was subjected to pressure filtration using a 3 μm pore Teflon (registered trademark) filter to obtain positive type photosensitive resin composition solutions (M1 to M7) of Examples 1 to 7.

(Comparative Examples 1-3)
The components (A) to (F) and the compound for comparative example were blended in the predetermined proportions shown in Table 1, and 2 parts by weight of a 50% methanol solution of urea propyltriethoxysilane was blended as a coupling agent. This solution was filtered under pressure using a Teflon (registered trademark) filter having a pore size of 3 μm to obtain solutions (M8 to M10) of positive photosensitive resin compositions of Comparative Examples 1 to 3.

表中、かっこ内の数値は重量部を示す。

In the table, the values in parentheses indicate parts by weight.

<Evaluation of positive photosensitive resin composition>
[Photosensitive characteristics]
The positive photosensitive resin composition solutions (M1 to M10) obtained in Examples 1 to 7 and Comparative Examples 1 to 3 were spin-coated on a silicon substrate, heated at 100 ° C. for 5 minutes, and a film thickness of 11 A coating of ˜13 μm was formed. Thereafter, reduction projection exposure was performed with i-line (365 nm) through a mask using an i-line stepper (FPA-3000iW manufactured by Canon). After the exposure, development was performed with a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH), and development was performed so that the remaining film thickness was about 70 to 95% of the initial film thickness. Thereafter, the substrate was rinsed with water, and the minimum exposure amount necessary for pattern formation and the size of the smallest open square hole pattern were determined. Table 2 shows the results of evaluation using the minimum exposure amount as sensitivity and the size of the smallest open square hole pattern as resolution.

[Patterning of cured film properties measurement sample]
The positive type photosensitive resin composition solutions (M1 to M10) obtained in Examples 1 to 7 and Comparative Examples 1 to 3 were spin-coated on a silicon substrate, and the temperature was 120 ° C. for 3 minutes (in Comparative Example 3). Heated at 100 ° C. for 5 minutes to form a coating film having a film thickness of about 12 to 14 μm. Thereafter, the coating films of the resins M1 to M10 were exposed at all wavelengths through a mask using a proximity exposure machine (PLA-600FA manufactured by Canon). After exposure, development was performed with a 2.38% aqueous solution of TMAH to obtain a 10 mm wide rectangular pattern. Thereafter, the coating film was heat-treated (cured) by the following method (i), (ii) or (iii) to obtain a cured film having a thickness of about 10 μm. Table 3 shows the curing conditions and the shrinkage ratio of the film thickness before and after curing ((1−film thickness after curing) / film thickness before curing) × 100) [%].
(I) Using a vertical diffusion furnace (μ-TF manufactured by Koyo Thermo System), the coating film was heat-treated in nitrogen at a temperature of 180 ° C. (heating time: 1.5 hours) for 2 hours.
(Ii) Using a vertical diffusion furnace (μ-TF manufactured by Koyo Thermo Systems Co., Ltd.), the coating film was heat-treated in nitrogen at a temperature of 200 ° C. (temperature rising time: 1.5 hours) for 2 hours.
(Iii) Using a frequency-variable microwave curing furnace (Microcure 2100 manufactured by Lambda Technology), microwave output 450 W, microwave frequency 5.9 to 7.0 GHz, temperature 170 ° C. (temperature rising time 5 minutes), heating for 2 hours Processed.

[Hardened film properties]
The cured film having a thickness of about 10 μm obtained in the above-mentioned “patterning of cured film physical property measurement sample” was peeled off from the silicon substrate, and the glass transition temperature (Tg) of the peeled film was measured with TMA / SS600 manufactured by Seiko Instruments Inc. Note that the width of the sample is 2 mm, the film thickness is 9 to 11 μm, and the distance between chucks is 10 mm. The load is 10 g, and the rate of temperature increase is 5 ° C./min. Further, the average breaking elongation (EL) of the release film was measured by an autograph AGS-H100N manufactured by Shimadzu Corporation. The width of the sample is 10 mm, the film thickness is 9 to 11 μm, and the distance between chucks is 20 mm. The pulling speed is 5 mm / min, and the measurement temperature is about room temperature (20 ° C. to 25 ° C.). Here, let the average of five or more measured values be "average breaking elongation (EL)" about the cured film obtained on the same conditions. The measured Tg and EL are shown in Table 3.

[Dielectric constant measurement]
The positive photosensitive resin composition solutions (M1 to M10) obtained in Examples 1 to 7 and Comparative Examples 1 to 3 were spin-coated on a low resistance silicon substrate and heated at 100 ° C. for 5 minutes to form a film. A coating film having a thickness of about 11 μm was formed. The coating film on the substrate was cured under the curing conditions shown in Table 3. Next, an aluminum electrode having a diameter of 2 mm was formed on the cured film using a vacuum deposition apparatus. Next, the charge capacity between the aluminum electrode and the silicon wafer was measured using a measuring apparatus in which a dielectric fixture Yokogawa Electric test fixture HP16451 was connected to the LF impedance analyzer HP4192A manufactured by Yokogawa Electric Corporation. The measurement environment was room temperature (20 ° C. to 25 ° C.), the humidity was 40% to 50% RH, the measurement frequency was 10 kHz, and the bias voltage was −35V. The relative dielectric constant of the cured film was determined from the measured charge capacity value of the electrode and the film thickness value near the electrode. The results are shown in Table 3.

  First, as apparent from Table 2, the sensitivity and resolution of the positive photosensitive resin compositions M1 to M7 of Examples 1 to 7 are high. On the other hand, in the photosensitive resin composition M8 containing no component (D) (Comparative Example 1), both sensitivity and resolution were lowered. Moreover, in the photosensitive resin composition M9 using a polyamic acid instead of the component (A), the remaining film ratio after development, the sensitivity, and the resolution were all low (Comparative Example 2). Furthermore, in the photosensitive resin composition M10 using a polyamic acid salt, it was insoluble in the developing solution used in this study, and no pattern was formed (Comparative Example 3).

  Further, as apparent from Table 3, the cured films formed from the positive photosensitive resin compositions M1 to M6 of Examples 1 to 6 all exhibited a low shrinkage of about 10%. The cured film of the positive type photosensitive resin composition M7 of Example 7 using poly (hydroxyamide) as the component (A) has a shrinkage of 15% due to the elimination of water due to the ring-closing reaction during curing. It was about. On the other hand, when polyamic acid or polyamic acid salt was used as the A component, the shrinkage rate was high and was 20% or more (Comparative Examples 2-3).

  Further, as is apparent from Table 3, the positive photosensitive resin compositions M1 to M7 of Examples 1 to 6 have good Tg (190 ° C. or higher) and EL (5% or higher) even when cured at 180 ° C. showed that. Moreover, although the positive photosensitive resin composition M7 of Example 7 was cured at 200 ° C., it exhibited good Tg and EL. Furthermore, when the positive photosensitive resin composition M1 of Example 1 was microwave-cured (curing condition iii) at 170 ° C., Tg and EL were higher than when it was thermally cured (curing condition i) at 180 ° C. Improved.

  Furthermore, as apparent from Table 3, in the case of the positive photosensitive resin compositions M5 and M6 of Examples 5 and 6 using poly (hydroxystyrene) as the component (A), the ratio of the cured film The dielectric constant was as good as 3 or less.

DESCRIPTION OF SYMBOLS 1 ... Semiconductor substrate, 2 ... Protective film, 3 ... 1st conductor layer, 4 ... Interlayer insulation film, 5 ... Photosensitive resin layer, 6A, 6B, 6C ... Window part, 7 ... 2nd conductor layer, 8 ... Surface protection 11 ... Interlayer insulating layer, 12 ... Wiring layer, 12 ... Underfill, 13 ... Insulating layer, 14 ... Surface protective layer, 15 ... Pad part, 16 ... Rewiring layer, 17 ... Conductive ball, 18 ... Core, DESCRIPTION OF SYMBOLS 19 ... Cover coat layer, 20 ... Barrier metal, 21 ... Color, 22 ... Underfill, 23 ... Silicon chip, 24 ... Connection part, 100, 200, 300, 400 ... Structure, 500 ... Semiconductor device, 600 ... Semiconductor device 700: Semiconductor device.

Claims (10)

(A) an alkali-soluble resin having a phenolic hydroxyl group,
(B) a compound that generates an acid by light,
(C) an elastomer,
(D) a low molecular compound having a phenolic hydroxyl group, and (E) a positive photosensitive resin composition containing a solvent,
The component (D) is 2,2-bis {3,5-bis (hydroxymethyl) -4-hydroxyphenyl} -1,1,1,3,3,3-hexafluoropropane or 1,1-bis A positive photosensitive resin composition which is {3,5-bis (methoxymethyl) -4-hydroxyphenyl} methane.   Positive photosensitivity in which the component (D) is 2,2-bis {3,5-bis (hydroxymethyl) -4-hydroxyphenyl} -1,1,1,3,3,3-hexafluoropropane Resin composition.   The positive photosensitive resin composition of Claim 1 or 2 whose said (A) component is a phenol resin.   The positive photosensitive resin composition according to claim 1 or 2, wherein the component (A) is a vinyl polymer containing a monomer unit having a phenolic hydroxyl group.   The positive photosensitive resin composition as described in any one of Claims 1-4 which contains 1-50 weight part of said (D) component with respect to 100 weight part of said (A) component.   The positive photosensitive resin composition as described in any one of Claims 1-5 whose said (B) component is an o-quinonediazide compound.   (F) The positive photosensitive resin composition as described in any one of Claims 1-6 which further contains the compound which produces | generates an acid by heating. A step of exposing a photosensitive resin film comprising the positive photosensitive resin composition according to any one of claims 1 to 7;
Developing and patterning the photosensitive resin film after exposure with an alkaline aqueous solution; and
Heating the patterned photosensitive resin film;
A method for producing a resist pattern comprising:   The method for producing a resist pattern according to claim 8, wherein the patterned photosensitive resin film is heated to 200 ° C or lower. An electronic device provided with the electronic component which has a resist pattern formed by the manufacturing method of the resist pattern of Claim 8 or 9 as an interlayer insulation film or a surface protective layer.

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