JP4564977B2 - Photosensitive resin composition, method for producing resist pattern, laminate, and device - Google Patents

Description

  The present invention relates to a photosensitive resin composition, a method for producing a resist pattern, a laminate, and a device, and in particular, has high sensitivity and high chemical stability capable of forming a fine resist pattern having a high film thickness and a high aspect ratio. The present invention relates to a photosensitive resin composition having the above, a method for producing a resist pattern using the same, a laminate obtained by the production method, and a device including the laminate.

  In recent years, MEMS (Micro Electro Mechanical System), which is attracting attention as a mass-productivity system that integrates fine parts in the same chip using semiconductor manufacturing technology and realizes high performance and high integration, Expansion to various fields such as automobiles, consumer devices, medical care and biotechnology is expected. The demand for downsizing in each of these fields is increasing, and development of a photosensitive resin composition capable of forming a fine resist pattern having a high film thickness and a high aspect ratio is required.

  However, the conventional photosensitive resin composition containing the novolak resin and the photoacid generator diazonaphthoquinone cannot obtain a profile having a high aspect ratio under a high film thickness. The diazonaphthoquinone photoacid generator exhibits high absorption for near-ultraviolet light used for exposure, and the resulting resin pattern has a tapered profile as a result of significantly different exposure intensity at the top and bottom of the thick film. This is because they are distorted or distorted.

  On the other hand, a photosensitive resin composition containing an epoxy resin and an acid generator has been proposed as a photosensitive resin composition capable of forming a fine resist pattern having a high film thickness and a high aspect ratio. Specifically, a photosensitive resin composition comprising an acid generator such as an epoxy-functional novolak resin or a triarylsulfonium salt and a diluent capable of reacting with an epoxy reactive group is disclosed (for example, see Patent Document 1). ). Also disclosed is a photosensitive resin composition comprising a multifunctional bisphenol A formaldehyde-novolak resin, an acid generator triphenylsulfonium hexafluoroantimonate, and a cyclopentanone solvent, and capable of forming a thick film ( For example, see Patent Document 2).

  On the other hand, besides the diazonaphthoquinone type photoacid generator, a photosensitive resin composition capable of forming a fine resist pattern having a high film thickness and a high aspect ratio has been proposed. For example, a photosensitive resin composition using an epoxy resin and an aromatic sulfonium cation polymerization initiator is disclosed (see Patent Documents 3 and 4). Moreover, the permanent film resist composition containing the cationic polymerization initiator which has absorption in the exposure light of 360 nm or more is disclosed (refer patent document 5).

The cationic polymerization initiator described above is usually composed of a cation part and an anion part. Examples of the anion moiety include SbF ₆ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , BF ₄ ^{− and the} like, and the order of sensitivity is known to be SbF ₆ ⁻ > AsF ₆ ⁻ > PF ₆ ⁻ > BF ₄ ^−. ing. Therefore, antimony (Sb) -based and arsenic (As) -based cationic polymerization initiators having high sensitivity are widely used.
Japanese Patent Publication No. 7-78628 US Pat. No. 6,391,523 JP 9-268205 A JP 2005-055865 A JP-A-10-097068

However, since antimony (Sb) is a deleterious substance and arsenic (As) is a toxic substance, the use of antimony (SbF ₆ ⁻ ) and arsenic (AsF ₆ ⁻ ) is preferable from the viewpoint of safety. I can not say. Phosphorus (PF ₆ ⁻ ) and boron (BF ₄ ⁻ ) cationic polymerization initiators require an exposure amount 10 times or more that of antimony to obtain permanent film properties equivalent to those of antimony. It was not expensive. In addition, the cationic polymerization initiator having SbF ₆ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , and BF ₄ ⁻ as an anion moiety liberates a fluorine atom from the anion moiety depending on the conditions of moisture and temperature, and from iron, aluminum and copper Corrosion of the board and wiring part.

  The present invention has been made in view of the above problems, and its purpose is to provide a high sensitivity, high sensitivity, excellent chemical stability, and capable of forming a fine resist pattern. It is in providing a conductive resin composition.

  As a result of intensive studies to achieve the above object, the present inventors have solved the above problems by using a polyfunctional epoxy resin and an onium salt-based cationic polymerization initiator having an anion portion having a specific structure. The present inventors have found that this can be done and have completed the present invention. Specifically, the present invention provides the following.

［化学式（ｂ１）中、Ｘ、Ｙ、及びＺは、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を示す。］ That is, the first aspect of the present invention is a photosensitive resin composition comprising (a) a polyfunctional epoxy resin, (b) a cationic polymerization initiator, and (d) a sensitizer.
The said (b) component contains the onium salt which has an anion part represented by following Chemical formula (b1), It is a photosensitive resin composition characterized by the above-mentioned.

[In the chemical formula (b1), X, Y, and Z each independently represent an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom. ]

  The second aspect of the present invention includes a lamination step of applying the photosensitive resin composition of the present invention on a support to obtain a thick film resist layer, and selectively active after the thick film resist layer is dried. An exposure step of irradiating light or radiation, a development step of developing after the exposure step to obtain a resin pattern, and a heat treatment step of obtaining a resist pattern made of a cured resin of a predetermined shape by heat-treating the resin pattern. This is a method for producing a resist pattern.

  A third aspect of the present invention is a laminate including a resist pattern and a support obtained by the method for producing a resist pattern of the present invention.

  4th aspect of this invention is a device containing the laminated body of this invention.

  According to the present invention, by using a polyfunctional epoxy resin and a photosensitive resin composition containing an onium salt-based cationic polymerization initiator having an anion moiety represented by the chemical formula (b1), safety is high. It is possible to obtain a photosensitive resin composition having a high sensitivity and excellent chemical stability and capable of forming a fine resist pattern.

  Hereinafter, embodiments of the present invention will be described in detail.

  The photosensitive resin composition according to the present invention is characterized by containing (a) a polyfunctional epoxy resin, (b) a cationic polymerization initiator, and (d) a sensitizer as described later.

<(A) Polyfunctional epoxy resin>
The (a) polyfunctional epoxy resin used in the photosensitive resin composition according to the present invention is not particularly limited as long as it is an epoxy resin having sufficient epoxy groups in one molecule to form a thick film resist pattern. Not. Examples of such polyfunctional epoxy resins include polyfunctional phenol / novolak type epoxy resins, polyfunctional orthocresol novolac type epoxy resins, polyfunctional triphenyl type novolac type epoxy resins, polyfunctional bisphenol A novolac type epoxy resins and the like. . Of these, polyfunctional bisphenol A novolac type epoxy resins are preferably used. The functionality is preferably 5 or more. For example, “Epicoat 157S70” manufactured by Japan Epoxy Resin Co., Ltd. and “Epicron N-865” manufactured by Dainippon Ink & Chemicals, Inc. are commercially available and particularly preferably used. .

The polyfunctional bisphenol A novolac type epoxy resin is represented by the following chemical formula (a1).

The polyfunctional bisphenol A novolac type epoxy resin of the chemical formula (a1) may be a polymer of a bisphenol A type epoxy resin or a bisphenol A novolac type epoxy resin and an epoxy group-containing component. In chemical formula (a1), R _{1 to} R ₆ are H or CH ₃ . n is an integer of 0-5.

  The softening point of the polyfunctional epoxy resin is not particularly limited as long as it is solid at room temperature. Usually, it is preferably about 50 ° C to about 100 ° C, more preferably about 60 ° C to about 80 ° C. .

  The content of the polyfunctional epoxy resin in the photosensitive resin composition is preferably 75% by mass to 99.9% by mass, and preferably 80% by mass to 99.9% by mass in the total solid content. More preferably, it is more preferably 92% by mass to 99.4% by mass. As a result, a thick resist layer with high sensitivity and appropriate hardness can be obtained when it is coated on the support.

<(B) Cationic polymerization initiator>
The cationic polymerization initiator (b) used in the photosensitive resin composition according to the present invention generates a cation moiety upon irradiation with an excimer laser such as ultraviolet ray, far ultraviolet ray, KrF or ArF, X-ray or electron beam. It is a compound whose cation part can serve as a polymerization initiator.

（化学式（ｂ１）中、Ｘ、Ｙ、及びＺは、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を示す。）
で表されるアニオン部を有するオニウム塩系のカチオン重合開始剤である。 Specifically, the cationic polymerization initiator (b) used in the photosensitive resin composition according to the present invention has the following chemical formula (b1):

(In the chemical formula (b1), X, Y, and Z each independently represent an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom.)
An onium salt-based cationic polymerization initiator having an anion moiety represented by the formula:

  Here, in the anion moiety represented by the chemical formula (b1), X, Y, and Z each independently represent an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. The alkyl group has 1 to 10 carbon atoms, preferably 1 to 7 carbon atoms, and more preferably 1 to 3 carbon atoms. Specific examples of the alkyl group include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl and octyl; branched alkyl groups such as isopropyl, isobutyl, sec-butyl and tert-butyl; and cyclopropyl, cyclobutyl and cyclopentyl. And the ratio of the hydrogen atom of the alkyl group substituted by a fluorine atom is preferably 50% or more, more preferably 80% or more, and most preferably 100%. Sensitivity to actinic rays and radiation of the thick film resist layer formed containing such a cationic polymerization initiator depends on the substitution rate of fluorine atoms rather than the number of carbon atoms of the alkyl group. By setting the ratio to at least%, the effect of the cationic polymerization initiating ability of the onium salt-based cationic polymerization initiator can be sufficiently obtained, and the photosensitivity of the thick film resist layer can be maintained.

Particularly preferred X, Y, and Z are linear or branched perfluoroalkyl groups having 1 to 3 carbon atoms and a fluorine atom substitution rate of 100%. Specific examples include CF ₃ , CF _{3 CF 2, (CF 3)} 2 CF, include _CF 3 CF ₂ CF 2. Among them, it is most preferable that all of X, Y, and Z are CF ₃ groups. By making all of X, Y, and Z a CF ₃ group having a strong electron-withdrawing property, the stability of the carbanion can be further increased.

（化学式（ｂ２）中、Ａは原子価ｍの硫黄原子、ヨウ素原子、リン原子、炭素原子、セレン原子、又は窒素原子を表し、ｍは１〜４である。特に好ましいＡは硫黄原子及びヨウ素原子であり、このときのｍは１〜２である。ｎは括弧内の構造の繰り返し単位数を表し、０〜３の整数である。ＲはＡに結合している有機基であり、炭素数６〜３０のアリール基、炭素数４〜３０の複素環基、炭素数１〜３０のアルキル基、炭素数２〜３０のアルケニル基、又は炭素数２〜３０のアルキニル基を表し、Ｒはアルキル、ヒドロキシ、アルコシキ、アルキルカルボニル、アリールカルボニル、アルコシキカルボニル、アリールオキシカルボニル、アリールチオカルボニル、アシロキシ、アリールチオ、アルキルチオ、アリール、複素環、アリールオキシ、アルキルスルフィニル、アリールスルフィニル、アルキルスルホニル、アリールスルホニル、アルキレンオキシ、アミノ、シアノ、ニトロの各基、及びハロゲンからなる群より選ばれる少なくとも１種で置換されていてもよい。Ｒの個数はｍ＋ｎ（ｍ−１）＋１であり、Ｒはそれぞれ互いに同じであっても異なっていてもよい。また、２個以上のＲが互いに直接、又は−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ_２−、−ＮＨ−、−ＮＲ’−、−ＣＯ−、−ＣＯＯ−、−ＣＯＮＨ−、炭素数１〜３のアルキレン基若しくはフェニレン基を介して結合し、Ａを含む環構造を形成してもよい。Ｒ’は炭素数１〜５のアルキル基又は炭素数６〜１０のアリール基である。
Ｄは下記化学式（ｂ３）で表される構造であり、

化学式（ｂ３）中、Ｅは炭素数１〜８のアルキレン基、炭素数６〜２０のアリーレン基、又は炭素数８〜２０の複素環化合物の２価の基を表し、Ｅは炭素数１〜８のアルキル、炭素数１〜８のアルコキシ、炭素数６〜１０のアリール、ヒドロキシ、シアノ、ニトロの各基、及びハロゲンからなる群より選ばれる少なくとも１種で置換されていてもよい。Ｇは−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ_２−、−ＮＨ−、−ＮＲ’−、−ＣＯ−、−ＣＯＯ−、−ＣＯＮＨ−、炭素数１〜３のアルキレン基、又はフェニレン基を表す。ａは０〜５の整数である。ａ＋１個のＥ及びａ個のＧはそれぞれ同一であっても異なっていてもよい。Ｒ’は前記のものと同じである。）
で表されることが好ましい。 On the other hand, although it does not specifically limit as a cation part of (b) component, following chemical formula (b2):

(In the chemical formula (b2), A represents a sulfur atom, an iodine atom, a phosphorus atom, a carbon atom, a selenium atom, or a nitrogen atom having a valence m, and m is 1 to 4. Particularly preferred A is a sulfur atom and iodine. In this case, m is 1 to 2. n is the number of repeating units in the parenthesis and is an integer of 0 to 3. R is an organic group bonded to A, carbon Represents an aryl group having 6 to 30 carbon atoms, a heterocyclic group having 4 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, or an alkynyl group having 2 to 30 carbon atoms; Alkyl, hydroxy, alkoxy, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, arylthiocarbonyl, acyloxy, arylthio, alkylthio, aryl, heterocycle, aryloxy , Alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl, alkyleneoxy, amino, cyano, nitro groups, and halogen may be substituted with at least one selected from the group consisting of m + n ( m-1) +1, and each R may be the same as or different from each other, and two or more R's may be directly each other, or -O-, -S-, -SO-, -SO _2. -, -NH-, -NR'-, -CO-, -COO-, -CONH-, bonded via an alkylene group having 1 to 3 carbon atoms or a phenylene group to form a ring structure containing A R ′ is an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 10 carbon atoms.
D is a structure represented by the following chemical formula (b3),

In chemical formula (b3), E represents an alkylene group having 1 to 8 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a divalent group of a heterocyclic compound having 8 to 20 carbon atoms, and E represents 1 to 1 carbon atoms. It may be substituted with at least one selected from the group consisting of 8 alkyls, C 1-8 alkoxys, C 6-10 aryls, hydroxy, cyano, nitro groups, and halogens. G is -O -, - S -, - SO -, - SO 2 -, - NH -, - NR '-, - CO -, - COO -, - CONH-, alkylene group having 1 to 3 carbon atoms, or Represents a phenylene group. a is an integer of 0-5. a + 1 E and a G may be the same or different. R ′ is the same as described above. )
It is preferable to be represented by

  The cation part of the component (b) is particularly preferably iodonium or sulfonium. By using iodonium or sulfonium as the cation part, the adhesion of the thick film resist layer to the support is enhanced, and the dissolution of the thick film resist layer in the developer is suppressed to form a finer resist pattern with high accuracy. Can do.

  (B) Preferable specific examples of onium ions constituting the cation part of the cationic polymerization initiator include triphenylsulfonium, tri-p-tolylsulfonium, 4- (phenylthio) phenyldiphenylsulfonium, bis [4- (diphenylsulfonio). ) Phenyl] sulfide, bis [4- {bis [4- (2-hydroxyethoxy) phenyl] sulfonio} phenyl] sulfide, bis {4- [bis (4-fluorophenyl) sulfonio] phenyl} sulfide, 4- (4 -Benzoyl-2-chlorophenylthio) phenylbis (4-fluorophenyl) sulfonium, 4- (4-benzoylphenylthio) phenyldiphenylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracene- 2-Ildi-p Tolylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldiphenylsulfonium, 2-[(diphenyl) sulfonio] thioxanthone, 4- [4- (4-tert-butylbenzoyl) ) Phenylthio] phenyldi-p-tolylsulfonium, 4- (4-benzoylphenylthio) phenyldiphenylsulfonium, diphenylphenacylsulfonium, 4-hydroxyphenylmethylbenzylsulfonium, 2-naphthylmethyl (1-ethoxycarbonyl) ethylsulfonium, 4 -Hydroxyphenylmethylphenacylsulfonium, octadecylmethylphenacylsulfonium, bis (4-tert-butylphenyl) iodonium, diphenyliodonium, di-p-tolyl Dodonium, bis (4-dodecylphenyl) iodonium, bis (4-methoxyphenyl) iodonium, (4-octyloxyphenyl) phenyliodonium, bis (4-decyloxy) phenyliodonium, 4- (2-hydroxytetradecyloxy) phenyl Examples include phenyliodonium, 4-isopropylphenyl (p-tolyl) iodonium, or 4-isobutylphenyl (p-tolyl) iodonium.

Among the onium salt-based (b) cationic polymerization initiators that satisfy the above requirements, triphenylsulfonium tris (trifluorosulfonyl) carbonate represented by the following chemical formulas (b4) and (b5), and bis (4-tert -Butylphenyl) iodonium tris (trifluorosulfonyl) carbonate is particularly preferably used.

  In the photosensitive resin composition according to the present invention, only one type of onium salt-based (b) cationic polymerization initiator having an anion moiety represented by the above chemical formula (b1) may be used. You may use together. Moreover, you may use together with another conventionally well-known cationic polymerization initiator. The ratio in the case of using two or more types in combination is arbitrary and is not particularly limited. Although the use ratio in the case of using other cationic polymerization initiators together may be arbitrary, usually 10 to 900 parts by mass of other cationic polymerization initiators, preferably 25 to 100 parts by mass of (b) cationic polymerization initiator. It is -400 mass parts.

  It is preferable that content of the said (b) cationic polymerization initiator is 0.5-20 mass parts with respect to 100 mass parts of said (a) polyfunctional epoxy resins. (B) By setting the content of the cationic polymerization initiator to 0.5 parts by mass or more, sufficient photosensitivity can be obtained. On the other hand, the permanent film characteristic of a thick resist layer increases by setting it as 20 mass parts or less. Specifically, water absorption and thermal decomposition temperature characteristics are improved.

Unlike the conventional antimony (SbF ₆ ⁻ ) and arsenic (AsF ₆ ⁻ ) cationic polymerization initiators used in the present invention, (b) cationic polymerization initiators have high safety to the human body. Further, (b) a cationic polymerization initiator having a high chemical stability of an anion portion containing carbanion, like a conventional cationic polymerization initiator composed of SbF ₆ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , and BF ₄ ⁻ Fluorine atoms are not liberated, and substrates and wiring parts made of iron, aluminum, and copper are not corroded and damaged.

  The photosensitive resin composition containing (a) a polyfunctional epoxy resin and (b) a cationic polymerization initiator of the present invention is as sensitive as an antimony polymerization initiator and has a fine resist pattern. Can be formed.

<(C) Bifunctional epoxy resin>
The photosensitive resin composition according to the present invention may contain (c) a bifunctional epoxy resin for improving film formability. Specifically, bisphenol A type epoxy or bisphenol F type epoxy is polymerized, and preferably has an average molecular weight of 1,000 to 7,000, more preferably 1,000 to 5,000, still more preferably. 1,000 to 3,000. When the average molecular weight is 1,000 or more, the film forming property is improved, and when the average molecular weight is 7,000 or less, the compatibility with the (a) polyfunctional epoxy resin can be maintained. For example, “Epicoat 1009” (average molecular weight 3,750) manufactured by Japan Epoxy Resin and “jER1004” (average molecular weight 1,650) manufactured by Japan Epoxy Resin are preferably used. In addition, the content of (c) the bifunctional epoxy resin is preferably added in the range of 1 to 30 parts by mass, and in the range of 10 to 25 parts by mass with respect to 100 parts by mass of the (a) polyfunctional epoxy resin. Is more preferable. The film-formability improves by setting it as 1 mass part or more, and it can balance with another component, especially (a) polyfunctional epoxy resin component by setting it as 30 mass parts or less.

<(D) Sensitizer>
The photosensitive resin composition according to the present invention may contain, as (d) a sensitizer, a sensitizer comprising a naphthalene derivative or anthracene or a derivative thereof that can be crosslinked with the above-mentioned (a) polyfunctional epoxy resin. preferable. By such a sensitizing function of the sensitizer, it is possible to further increase the sensitivity of the photosensitive resin composition even when the (b) cationic polymerization initiator that does not absorb I rays is used. . Among these, it is particularly preferable to contain a sensitizer composed of dihydroxynaphthalene having two hydroxyl groups or anthracene. Since these sensitizers have a plurality of aromatic rings, the thick film resist layer can have a high Tg, a high hardness, and a low coefficient of thermal expansion.

  Specific examples of the (d) sensitizer used in the present invention include 2,3-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1-naphthol, and anthracene. Among these, 1,5-dihydroxynaphthalene, 1-naphthol, and anthracene can be preferably used. By using these alone or in combination, the thick film resist layer can be made more sensitive. Content of these (d) sensitizers is 1-50 mass parts with respect to 100 mass parts of said (a) polyfunctional epoxy resins. By setting it as such a composition ratio, a desired effect is acquired, without deteriorating a resist pattern shape.

The present invention is equivalent to a highly sensitive antimony (SbF ₆ ⁻ ) in order to provide a highly sensitive and high resolution photosensitive resin composition capable of forming a fine resist pattern having a high film thickness and a high aspect ratio. As a cationic polymerization initiator capable of obtaining a permanent film property, an onium salt-based cationic polymerization initiator having an anion moiety represented by the above chemical formula (b1) is used. Therefore, by using the above sensitizer together, a photosensitive resin composition having higher sensitivity and higher resolution can be provided.

<(E) Solvent>
The (e) solvent used for the photosensitive resin composition of this invention is not specifically limited, A conventionally well-known solvent can be used. Examples include γ-butyrolactone, ethyl lactate, propylene carbonate, propylene glycol monomethyl ether acetate, methyl isobutyl ketone, butyl acetate, methyl amyl ketone, 2-heptanone, ethyl acetate, and methyl ethyl ketone.

  Among the above solvents, in the case of a liquid resist, ethyl lactate, γ-butyrolactone, and propylene carbonate are preferable from the viewpoint of reacting and being incorporated into a thick film resist layer. In the case of a dry film, From the viewpoint of wettability and surface tension, propylene glycol monomethyl ether acetate, methyl isobutyl ketone, butyl acetate, and methyl amyl ketone are preferably used. These solvents may be used independently and may mix 2 or more types.

<(F) Other components>
The photosensitive resin composition of the present invention contains an oxetane derivative or an epoxy derivative from the viewpoint of improving the flexibility of the photosensitive resin composition before curing without reducing the physical properties after curing of the photosensitive resin composition. You may let them. Among these, the curability of the thick film resist layer can be further increased by including the oxetane derivative in the photosensitive resin composition.

  Further, if desired, miscible additives such as additional resins, plasticizers, stabilizers, colorants, coupling agents, leveling agents and the like conventionally known for improving the performance of the resist pattern may be used. It can be contained as appropriate. For example, with respect to 100 parts by mass of the (a) polyfunctional epoxy resin, 0.5 to 30 parts by mass of a coupling agent made of epoxy silane and 0.01 to 0.1 parts by mass of a leveling agent are added. it can.

<Method for producing resist pattern>
The photosensitive resin composition constituted as described above may be applied directly on a support to form a thick film resist layer to produce a resist pattern, or a thick film resist formed from the photosensitive resin composition The both surfaces of the layer may be protected with a protective film to form a dry film, which may be affixed on a support to produce a resist pattern. As the protective film for the dry film, it is preferable to use a polymer film of any one of a polyethylene terephthalate film, a polypropylene film, and a polyethylene film.

  The support on which the photosensitive resin composition is applied or the dry film is attached is not particularly limited, and a conventionally known one can be used. For example, a substrate for an electronic component or a predetermined wiring pattern on the substrate. Can be exemplified. Examples of the substrate include a metal substrate such as silicon, silicon nitride, titanium, tantalum, palladium, titanium tungsten, copper, chromium, iron, and aluminum, a glass substrate, and the like. In particular, the photosensitive resin composition of the present invention can satisfactorily form a resist pattern on a support made of copper, iron, and aluminum, particularly preferably on a copper or aluminum substrate. As a material for the wiring pattern, for example, copper, solder, chromium, aluminum, nickel, gold or the like is used.

  When a photosensitive resin composition is directly coated on a support to form a thick film resist layer, the photosensitive resin composition is coated with a spin coater and dried, and then actinic rays or radiation is used. By performing pattern exposure and developing with a developer, a resist pattern made of a cured resin that is faithful to the mask pattern and good can be formed without depending on the support to be used.

  When a dry film is attached on a support to form a resist pattern, a desired pattern can be formed more easily using the photosensitive resin composition of the present invention. Specifically, one of the protective films of the dry film is removed to expose one surface of the thick film resist layer, and the laminated surface is attached to the support to expose the other surface. After removing the film, perform an exposure process of pattern exposure using actinic rays or radiation, etc., perform a development process of developing this with a developer, and perform a heat treatment process of heat-treating the obtained resin pattern Thus, a drying process can be omitted, and a resist pattern made of a cured resin that is faithful to the mask pattern and good can be formed. The exposure process may be performed first in a state where the dry film is attached to the support, and then the other protective film may be removed.

  A laminate including the resist pattern and the support thus obtained is a microfabricated device such as a gyro sensor, an image sensor, a SAW (Surface Acoustic Wave) filter, a BAW (Bulk Acoustic Wave) filter, It is preferably used for electronic paper, inkjet head, biochip, package without sealant, and sealant.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Examples 1-6, Comparative Examples 1-5>
A photosensitive resin composition containing a polyfunctional epoxy resin, a cationic polymerization initiator, a solvent, and other components was obtained according to the formulation shown in Table 1 (unit: parts by mass).

  These photosensitive resin compositions were applied onto a support made of a silicon wafer by a spin coater and then dried to obtain a photosensitive resin composition layer having a thickness of 30 μm. This photosensitive resin composition layer was pre-baked at 90 ° C. for 10 minutes using a hot plate. After pre-baking, pattern exposure (soft contact, GHI line) was performed using PLA-501F (contact aligner: manufactured by Canon), and post-exposure heating (PEB) was performed at 90 ° C. for 5 minutes using a hot plate. Then, the development process for 8 minutes was performed by the immersion method using PM Thinner. Next, the developed resin pattern was post-baked for 1 hour at 200 ° C. using an oven together with the substrate to obtain a resist pattern cured on the support.

  Here, in Comparative Examples 1 to 4, diphenyl [4- (phenylthio) phenyl] sulfonium trifluorotrispentafluoroethyl phosphate having no carbanion was used as the cationic polymerization initiator. In Comparative Example 5, a cresol novolac resin and a melamine-based crosslinking agent were used instead of the polyfunctional epoxy resin, and immersion for 5 minutes in TMAH 3.0% was performed as a development treatment.

<Evaluation>
In the evaluation of sensitivity, ultraviolet exposure was carried out stepwise in the range of 200 to 2000 mJ / cm ² , and the exposure required to form a 5 μm line pattern / 5 μm space pattern was measured. Furthermore, in the evaluation of the fine line adhesion, the formed pattern was observed with a scanning electron microscope (SEM), and the most closely adhered fine pattern width in the pattern formed with this necessary exposure amount was measured. These evaluation results are shown in Table 1.

(A-1): Multifunctional bisphenol A novolac type epoxy resin: jER157S70 (trade name, manufactured by Japan Epoxy Resin Co., Ltd.)
(A-2): Multifunctional bisphenol A novolac type epoxy resin: Epicron N-885 (trade name, manufactured by Dainippon Ink & Chemicals, Inc.)
(B-1): Cationic polymerization initiator: triphenylsulfonium tris (trifluorosulfonyl) carbonate (B-2): Cationic polymerization initiator: bis (4-tert-butylphenyl) iodonium tris (trifluorosulfonyl) carbonate ( B-3): Cationic polymerization initiator: diphenyl [4- (phenylthio) phenyl] sulfonium hexafluorophosphate (B-4): Cationic polymerization initiator: dimethyl (4,7-dihydroxynaphthalene) sulfonium nonafluorobutanesulfonate ( C): Bifunctional epoxy resin: jER1004 (trade name, manufactured by Japan Epoxy Resin Co., Ltd.)
(D-1): Sensitizer: 1-naphthol (D-2): Sensitizer: Anthracene (E-1): Solvent: γ-butyrolactone (E-2): Solvent: Ethyl lactate (F-1) : Oxetane derivative: 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene (F-2): Leveling agent: Paindad M (trade name, manufactured by Dow Corning)
(G): Cresol novolac resin: GTR-B9 (trade name, manufactured by Gunei Chemical Industry Co., Ltd.)
(H): Melamine-based crosslinking agent: MW-100LM (trade name, manufactured by Sanwa Chemical Co., Ltd.)

In Examples 1-6, when the resist pattern was formed using the cationic polymerization initiator which has an anion part represented by the said Chemical formula (b1), and a polyfunctional epoxy resin, with a small exposure amount of 300 mJ / cm < ² >. A resist pattern could be formed. The pattern width formed at this time was as fine as 6 to 10 μm.

On the other hand, when a cationic polymerization initiator having a phosphorus-based (PF ₆ ⁻ ) anion part and a polyfunctional epoxy resin were used as in Comparative Examples 1 to 4, the exposure amount increased to 1500 mJ / cm ² , The pattern width sometimes formed was as coarse as 12 to 16 μm. Further, when a resin different from the polyfunctional epoxy resin was used as in Comparative Example 5, the exposure amount was further increased to 2000 mJ / cm ^2, and at this time, a fine line having a pattern width of 20 μm did not adhere to the support.

In addition, as in Comparative Example 6, when a cationic polymerization initiator having a sulfonic acid (C ₄ F ₉ SO ₃ ⁻ ) anion portion was used, even when the exposure amount was 1000 mJ / cm ² , The irradiated portion of the thick resist layer was dissolved in the developer. Even when the exposure amount was 2000 mJ / cm ² , a so-called solid film was only formed on the support. Even when the exposure amount was 4000 mJ / cm ² , the thin resist pattern with a pattern width of 120 μm did not adhere to the support.

Moreover, about the photosensitive resin composition of Example 1 and the comparative example 1, the resist pattern was formed by the method similar to the above except having used the aluminum sputter wafer for the support body, and the pressure cooker test was done. The corrosion of the aluminum sputtered wafer after 96 hours under the conditions of 121 ° C.-95% RH and 1.0 kgf / cm ² was observed with a metal microscope. In the photosensitive resin composition of Example 1, no corrosion was observed on the support, but in the photosensitive resin composition of Comparative Example 1, corrosion was observed on the support.

  From the above, it was proved that the photosensitive resin composition of the present invention has high safety and good sensitivity (more than 5 times that of the comparative example). Further, the fine line adhesion is good, a finer resist pattern can be obtained, and the substrate is not corroded. Therefore, it can be suitably used for various devices subjected to microfabrication such as for MEMS.

Claims (9)

A photosensitive resin composition comprising (a) a polyfunctional epoxy resin, (b) a cationic polymerization initiator, and (d) a sensitizer,
The component (a) is a polyfunctional bisphenol A novolac type epoxy resin,
The said (b) component contains the onium salt which has an anion part represented by following Chemical formula (b1), The photosensitive resin composition characterized by the above-mentioned.

[In the chemical formula (b1), X, Y, and Z each independently represent an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom. ] Further, (c) the photosensitive resin composition of claim 1 comprising a bifunctional epoxy resin. The photosensitive resin composition according to claim 1 or 2 , wherein the cation part of the component (b) is at least one selected from iodonium and sulfonium. Dry film characterized by comprising forming a duplex in the protective film of the thick-film resist layer formed from the photosensitive resin composition according to any one of claims 1 to 3. A lamination step of obtaining a thick resist layer by applying the photosensitive resin composition according on a support in any of claims 1 to 3,
A drying step of drying the thick film resist layer;
An exposure step of selectively irradiating the dried thick resist layer with actinic rays or radiation; and
A development step of developing the thick resist layer after the exposure step to obtain a resin pattern;
And a heat treatment step of obtaining a resist pattern made of a cured resin having a predetermined shape by heat-treating the resin pattern. A lamination step of removing one of the protective films of the dry film according to claim 4 to expose one surface of the thick film resist layer, and affixing the exposed surface on a support;
An exposure step of selectively irradiating the thick resist layer with actinic rays or radiation after removing the other protective film of the dry film;
A development step of developing the thick resist layer after the exposure step to obtain a resin pattern;
A heat treatment step of heat-treating the resin pattern to obtain a resist pattern made of a cured resin having a predetermined shape. A lamination step of removing one of the protective films of the dry film according to claim 4 to expose one surface of the thick film resist layer, and affixing the exposed surface on a support;
An exposure step of selectively irradiating the thick film resist layer with actinic rays or radiation; and
After removing the other protective film of the dry film, developing the thick film resist layer to obtain a resin pattern; and
A heat treatment step of heat-treating the resin pattern to obtain a resist pattern made of a cured resin having a predetermined shape. The laminated body containing the resist pattern and support body which were obtained by the manufacturing method in any one of Claim 5 to 7 . A device comprising the laminate according to claim 8 .