JP2005284208A - Photosensitive resin composition and pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition, capable of forming a resist pattern having a cross section of inverted tapered shape, markedly superior in heat resistance and in adhesion, even with respect to a substrate having high smoothness, without deteriorating the storage stability. <P>SOLUTION: The photosensitive resin composition comprises an alkali-soluble resin, a crosslinking component, which crosslinks the alkali-soluble resin upon irradiation with actinic ray, or irradiation with the actinic ray and the subsequent heat treatment, a compound which absorbs an actinic ray, and a polyvinyl alkyl ether. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photosensitive resin composition used as a resist material in the photolithography technical field, and more specifically, in addition to being capable of forming a resist pattern having a reverse tapered cross section and excellent heat resistance, The present invention relates to a photosensitive resin composition in which adhesion between a resist pattern and a highly smooth substrate is remarkably improved and storage stability is excellent. The present invention also relates to a pattern forming method using the photosensitive resin composition.

  The photosensitive resin composition of the present invention includes an electrically insulating partition wall forming material in an organic electroluminescence display panel (hereinafter referred to as “organic EL display element”), and a pattern forming resist having a reverse tapered cross section by a lift-off method. Suitable as a material.

  In a photolithography technique using a resist material, a resist material capable of forming a resist pattern profile having a reverse taper in cross section may be required. Specifically, there are a case where a pattern is formed by a lift-off method and a case where an electrically insulating partition wall of an organic EL display element is formed.

  The lift-off method is applied to, for example, formation of a conductor pattern, formation of a thermal head heating element, correction of a white defect in a photomask, and the like. In order to form a conductor pattern using a resist material by the lift-off method, (1) a step of forming a resist film on a substrate, (2) the resist film is exposed in a pattern, developed, and a negative resist pattern (Negative image) forming step, (3) forming a deposited film by depositing metal on the entire surface of the substrate including the negative resist pattern, and (4) immersing the entire substrate in the solution to form a negative resist pattern. The conductor pattern is formed on the substrate by a series of steps including the step of swelling and dissolving the substrate. In the step (4), together with the negative resist pattern, the deposited film thereon is also removed, and only the deposited film on the substrate remains in a pattern.

  In the step (2), as shown in FIG. 1, if a negative resist pattern 2 having a reverse taper cross section is formed on the substrate 1, a metal deposition film is formed on the entire surface of the substrate in the next step (3). When formed, the vapor deposition film 3 and the vapor deposition film 3 ′ are independently formed on the substrate 1 and the negative resist pattern 2. Therefore, if the negative resist pattern 2 is removed in the step (4), the vapor deposition film 3 ′ thereon is also removed, and only the pattern of the vapor deposition film 3 remains on the substrate 1.

  On the other hand, when the resist pattern profile has a cross-sectional shape such as a rectangle, a forward taper shape, or a skirt shape, in the step (3), when a metal vapor deposition film is formed on the entire surface of the substrate, the resist pattern profile is also formed on the side surface of the resist pattern. Since the deposited film is formed, the deposited film on the substrate and the deposited film on the resist pattern are continuously formed. For example, as shown in FIG. 5, when the cross-sectional shape of the resist pattern 52 formed on the substrate 51 is a forward taper shape, if the metal vapor deposition film 53 is formed on the entire surface of the substrate, the vapor deposition film is also formed on the side surface of the pattern. Is formed. For this reason, when the resist pattern 52 is removed in the step (4), not only the deposited film formed on the resist pattern 52 but also part or all of the deposited film on the substrate continuous thereto is peeled off.

  In the pattern formation by the lift-off method, not only a typical reverse tapered cross-section resist pattern, but also a resist pattern 42 having an overhang cross section having an overhang portion 43 on a substrate 41 as shown in FIG. Also good. Therefore, in the present invention, the “reverse taper shape” includes a case where the cross-sectional shape is an overhang shape.

  The resist material for forming an electrically insulating partition in an organic EL display element is required to be able to form a reverse tapered resist pattern profile. The organic EL display element is a self-luminous type that has no viewing angle limitation, high brightness, can thin the panel, can be driven at a low voltage, has a fast reaction speed, and has three primary colors of RGB (red blue green). It is possible to make it full color. However, since the organic EL material has low resistance to the organic solvent, the etching process cannot be performed. Therefore, it has been difficult to form a matrix structure as a display element by applying fine processing by a photolithography technique. Therefore, the organic EL display element is mainly used as a backlight for a liquid crystal display.

  In recent years, new proposals have been made regarding the formation technology of display elements using organic EL materials. Specifically, (1) A plurality of stripe patterns made of indium tin oxide (ITO) are formed on a transparent substrate and used as a first display electrode (anode). (2) From above Then, a negative resist composition is applied to the entire surface of the substrate to form a resist film, and (3) exposure is performed through a striped photomask orthogonal to the ITO striped pattern, followed by post-exposure heat treatment (Post Exposure Baking; PEB) and developing to form a striped negative resist pattern. (4) Organic EL materials (hole transport material and electron transport material) are sequentially deposited on this substrate. (5) Furthermore, a method for manufacturing an organic EL display element by vapor-depositing a metal such as aluminum has been proposed (Patent Document 1).

  In this organic EL display element, the negative resist pattern serves as an electrically insulating partition. That is, as shown in FIG. 2, an ITO film (anode) 22 patterned in a stripe shape is formed on a transparent substrate 21, and then a striped negative resist pattern 23 perpendicular to the ITO film is formed. If the negative resist pattern has a reverse taper cross section, when an organic EL material is vapor-deposited thereon, a stripe-shaped organic EL material vapor deposition film 24 orthogonal to the ITO film 22 is independently formed on the substrate 21. It is formed. Even when the organic EL material is deposited on the negative resist pattern, the deposited film 24 'is independent of the deposited film 24 on the substrate.

  Further, when a metal such as aluminum is vapor-deposited thereon, independent metal vapor deposition films 25 and 25 are formed on the organic EL material vapor deposition film 24 on the substrate and the organic EL material vapor deposition film 24 'on the negative resist pattern, respectively. 'Is formed. The metal vapor deposition film 25 formed on the vapor deposition film 24 of the organic EL material becomes the second display electrode (cathode). Adjacent second display electrodes (cathodes) are separated from each other by a negative resist pattern and electrically insulated. The ITO film (anode) 22 and the metal vapor-deposited film (cathode) 25 are separated by the vapor-deposited film 24 of the organic EL material and do not short-circuit.

  When the organic EL material is vapor-deposited by sequentially depositing the organic EL materials of each color of RGB using a vapor deposition mask, the vapor-deposited film 34a of the organic EL material of each color is formed on the transparent substrate 31 and the ITO film 32 as shown in FIG. (R), 34b (G), and 34c (B) are formed. When the negative resist pattern is covered with a vapor deposition mask, a vapor deposition film of an organic EL material is hardly formed thereon. Further, when a metal such as aluminum is vapor-deposited thereon, metal vapor-deposited films 35 and 35 'are independently formed on the vapor-deposited film of each color organic EL material and on the negative resist pattern.

  In the organic EL display element having such a structure, the first display electrode and the second display electrode intersect with each other, and a vapor deposition film portion of the organic EL material sandwiched between both electrodes serves as a light emitting portion. The negative resist pattern is left as an electrically insulating partition without being removed.

  Conventionally, a method of forming a reverse tapered resist pattern by an image reversal method using a positive photoresist made of a novolak resin and a quinonediazide compound is known. However, in this image reversal method, in addition to the complicated operation, the allowable range of the heating temperature during the heat treatment (amine diffusion and heating) is narrow, and it is difficult to obtain a resist pattern having a good shape. .

  Conventionally, there has been proposed a negative resist composition containing at least one component that crosslinks by light exposure or exposure and subsequent heat treatment, an alkali-soluble resin, and a compound that absorbs light to be exposed, and an alkaline aqueous solution as a developer. (Patent Document 2). When this negative resist composition is used, it is possible to form a resist pattern having a reverse taper in cross section suitable for the lift-off method.

  However, the above inversely tapered resist pattern has a problem that heat resistance is not sufficient. Formation of the metal vapor deposition film by the lift-off method is performed at a high temperature. The electrically insulating partition in the organic EL display element must withstand the steps of vapor deposition of organic EL material and metal vapor deposition under high temperature conditions and maintain the shape thereof. In particular, when an organic EL material is deposited, in order to widen a sublimation temperature margin (allowable range), it is required to improve the heat resistance of an electrically insulating partition made of a resist pattern. Furthermore, since the organic EL display element is used for portable devices, on-vehicle devices, and the like, it is required to have durability enough to withstand high temperature conditions such as temperature rise in the vehicle. However, such a requirement cannot be met with a resist pattern having low heat resistance.

  In view of this, various proposals have been made on resist materials that can form a pattern having a reverse taper cross section and good heat resistance. For example, (1) a radiation-sensitive resin composition for forming partition walls of an EL display element containing an alkali-soluble resin, melamines, and trihalomethyltriazines and / or onium salts (Patent Document 3), (2) methylolated A method of forming a reverse-tapered resist pattern using a negative photosensitive resin composition containing an alkali-soluble resin obtained by polycondensation of a bisphenol compound and a phenol compound with an aldehyde (Patent Document 4) (3) In a negative photosensitive resin composition containing an alkali-soluble novolak resin, a crosslinking agent, and a photoacid generator, the alkali-soluble novolak resin is an alkali having a molecular weight ratio of 500 or less by fractionation. It is preferably used as an electrode partition material for organic EL displays, which is a soluble novolak resin. A negative photosensitive resin composition having a wide process margin (Patent Document 5), (4) an alkali-soluble resin, a component that crosslinks an alkali-soluble resin by irradiation with actinic rays or actinic rays and subsequent heat treatment, and actinic rays There has been proposed a resist composition (Patent Document 6) containing a compound that absorbs water, wherein the alkali-soluble resin is a resin composition of polyvinylphenol and a novolac resin.

  However, the present situation is that a sufficiently satisfactory photosensitive resin composition has not been obtained even by these conventional techniques. For example, in order to form an electrically insulating partition of an organic EL display element using a photosensitive resin composition, on a transparent substrate (hereinafter sometimes referred to as “ITO substrate”) having an ITO film patterned in a stripe shape. In this case, a stripe-like resist pattern is formed so as to be orthogonal to the stripe-like ITO film. However, since the ITO substrate used for manufacturing the organic EL display element is very smooth compared to the ITO substrate for a liquid crystal display element (LCD), the anchor effect is difficult to obtain, and the resist pattern and the ITO substrate surface The adhesion between the two tends to be insufficient.

  Patent Document 3 describes that a compound containing two or more epoxy groups in the molecule, such as an epoxy resin or a polyglycidyl ether, is added to improve the adhesion of the radiation-sensitive resin composition. Has been. Patent Document 4 describes that hexamethyldisilazane or chloromethylsilane is added as an adhesion assistant to the negative photosensitive resin composition.

  However, since epoxy compounds, hexamethyldisilazane, and chloromethylsilane are reactive with acids, bases, moisture, etc., they reduce the storage stability of the photosensitive resin composition. In the first place, since all of the resist materials are actinic radiation amplification type photosensitive resin compositions, a chain chemical reaction is likely to occur, and the storage stability is not sufficient. Therefore, in order to improve the adhesion to the ITO substrate, blending additives having reactivity with each component of the photosensitive resin composition and moisture impairs the storage stability of the photosensitive resin composition. It is necessary to avoid it.

JP-A-8-315981 JP-A-5-165218 JP 2002-83687 A Japanese Patent No. 3320395 JP 2002-278067 A Republished patent WO01 / 064101

  The problem of the present invention is that, in addition to being able to form a resist pattern having a reverse tapered cross section and excellent heat resistance, the adhesion between the resist pattern and a highly smooth substrate is remarkably improved and stored. It is providing the photosensitive resin composition excellent also in stability. The other subject of this invention is providing the pattern formation method using the photosensitive resin composition excellent in such various characteristics.

  As a result of intensive studies to achieve the above object, the present inventors have found that an alkali-soluble resin, a crosslinking component that crosslinks the alkali-soluble resin by irradiation with actinic rays or irradiation with actinic rays and subsequent heat treatment, and actinic rays. In a photosensitive resin composition containing a compound to be absorbed, by containing polyvinyl alkyl ether, a resist pattern that can exhibit sufficient adhesion even to an ITO substrate having high smoothness without impairing storage stability The present inventors have found that a photosensitive resin composition capable of forming a film is obtained.

  When a resist pattern is formed on a substrate using the photosensitive resin composition of the present invention, a resist pattern having a reverse taper section, excellent heat resistance, and excellent adhesion to the substrate can be formed. The photosensitive resin composition of the present invention is suitably used as a negative resist material because the molecular weight of the alkali-soluble resin in the exposed region is increased by the action of the crosslinking component, and the dissolution rate is extremely reduced in an alkali developer. It is done. The present invention has been completed based on these findings.

  According to the present invention, an alkali-soluble resin (a), a crosslinking component (b) that crosslinks the alkali-soluble resin by irradiation with actinic rays or actinic rays and subsequent heat treatment, a compound (c) that absorbs actinic rays, and polyvinyl A photosensitive resin composition containing an alkyl ether (d) is provided.

  The photosensitive resin composition of this invention can improve adhesiveness with a board | substrate, without impairing storage stability by containing polyvinyl alkyl ether. When the photosensitive resin composition of the present invention is used, it is possible to form a resist pattern having a reverse taper section, excellent heat resistance, and excellent adhesion to the substrate.

  Since the photosensitive resin composition of the present invention can form a resist pattern with excellent adhesion even on an ITO substrate with high smoothness for organic EL display elements, it can form an electrically insulating partition. Is preferred. In addition, the photosensitive resin composition of the present invention can be used for a wide range of applications as a resist material for pattern formation having a reverse taper-shaped cross section by a lift-off method.

1. Alkali-soluble resin:
As alkali-soluble resin, what is used in this technical field, such as novolak resin and polyvinylphenol, can be used. In the present invention, from the viewpoint of the heat resistance of the resist pattern, it is preferable to use a resin composition containing polyvinylphenol and a novolac resin as the alkali-soluble resin. The proportion of polyvinylphenol in the alkali-soluble resin is usually 30 to 95% by weight, preferably 35 to 90% by weight, and more preferably 40 to 80% by weight. Therefore, the proportion of the novolak resin is 5 to 70% by weight, preferably 10 to 65% by weight, and more preferably 20 to 60% by weight.

  If the proportion of polyvinylphenol is too large, the resist pattern may be easily peeled off from the substrate, or a protrusion-like shape abnormality may occur on the side wall of the resist pattern. When the ratio of polyvinyl phenol is too small, the heat resistance is insufficient. A photosensitive resin composition capable of forming a resist pattern having an inversely tapered cross section, excellent heat resistance, and suppressed peeling from the substrate, when the blending ratio of polyvinylphenol and novolac resin is within the above range. You can get things.

  Examples of polyvinylphenol include vinylphenol homopolymers and copolymers of vinylphenol and monomers copolymerizable therewith. Examples of the monomer copolymerizable with vinylphenol include isopropenylphenol, acrylic acid, methacrylic acid, styrene, maleic anhydride, maleic imide, and vinyl acetate. As the polyvinylphenol, a vinylphenol homopolymer is preferable, and a p-vinylphenol homopolymer is more preferable.

  The average molecular weight of polyvinylphenol is a weight average molecular weight (Mw) in terms of monodisperse polystyrene measured by gel permeation chromatography (GPC), and is usually 3000 to 20000, preferably 4000 to 15000, and more preferably 5000 to 10,000. If the average molecular weight of polyvinylphenol is too low, the molecular weight will not increase sufficiently even if the exposed region undergoes a cross-linking reaction, so that it will be easily dissolved in an alkaline developer and the heat resistance will also be reduced. If the average molecular weight of polyvinylphenol is too large, the difference in solubility between the exposed region and the unexposed region with respect to an alkaline developer becomes small, making it difficult to obtain a good resist pattern.

  As the novolac resin, those widely used in the technical field of resists can be used. The novolak resin can be obtained, for example, by reacting phenols with aldehydes or ketones in the presence of an acidic catalyst (for example, oxalic acid).

  Examples of phenols include phenol, orthocresol, metacresol, paracresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2,4- Dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, 2-t-butylphenol, 3-t-butylphenol, 4-t-butylphenol, 2-methylresorcinol 4-methylresorcinol, 5-methylresorcinol, 4-t-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 2- Meto Shi-5-methylphenol, 2-t-butyl-5-methylphenol, thymol, and the like Isochimoru. These can be used alone or in combination of two or more.

  Examples of aldehydes include formaldehyde, formalin, paraformaldehyde, trioxane, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p- Hydroxybenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde, terephthalaldehyde, etc. It is done. Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, and diphenyl ketone. These can be used alone or in combination of two or more.

  Among the above, a novolak resin obtained by concomitant use of metacresol and paracresol and a condensation reaction of these with formaldehyde, formalin or paraformaldehyde is particularly preferable from the viewpoint of sensitivity controllability. The charging weight ratio of metacresol to paracresol is usually 80:20 to 20:80, preferably 70:30 to 50:50.

  The average molecular weight of the novolak resin is a weight average molecular weight in terms of monodisperse polystyrene measured by GPC, and is usually 1000 to 10,000, preferably 2000 to 7000, and more preferably 2500 to 6000. If the average molecular weight of the novolak resin is too low, the effect of increasing the molecular weight is small even when a crosslinking reaction occurs in the exposed area, and the novolak resin is easily dissolved in an alkali developer. If the average molecular weight of the novolak resin is too high, the difference in solubility between the exposed area and the unexposed area in the alkaline developer becomes small, and it becomes difficult to obtain a good resist pattern.

  The weight average molecular weights of polyvinylphenol and novolac resin can be controlled within a desired range by adjusting the synthesis conditions. In addition, for example, (1) a method of pulverizing a resin obtained by synthesis and solid-liquid extraction with an organic solvent having an appropriate solubility, (2) dissolving the resin obtained by synthesis in a good solvent, The weight average molecular weight can be controlled by, for example, dropping into a solvent or dropping a poor solvent to perform solid-liquid or liquid-liquid extraction.

  The measurement of the weight average molecular weight by GPC is implemented on condition of the following using SC8020 (made by TOSO) as a GPC measuring apparatus.

Column: A combination of one each of TSKGEL G3000HXL and G200HXL1000 manufactured by TOSO,
Temperature: 38 ° C
Solvent: tetrahydrofuran,
Flow rate: 1.0 ml / min,
Sample: 0.1 ml of a sample having a concentration of 0.05 to 0.6% by weight was injected.

2. Crosslinking component:
The crosslinking component used in the present invention is a component that crosslinks the alkali-soluble resin by irradiation with actinic rays or irradiation with actinic rays and subsequent heat treatment. Due to the action of the crosslinking component, the molecular weight of the alkali-soluble resin in the exposed region is increased, and the dissolution rate in the alkali developer is extremely reduced. Thereby, the photosensitive resin composition of the present invention functions as a negative resist material that can be developed with an alkaline developer.

  As a crosslinking component, (1) a photopolymerization initiator (for example, a benzophenone derivative, a benzoin derivative, a benzoin ether derivative, etc.) that generates radicals upon irradiation with actinic rays, and a compound having an unsaturated hydrocarbon group that is polymerized by the radicals A combination of [for example, pentaerythritol tetra (meth) acrylate, etc.] and, if necessary, a sensitizer for increasing the efficiency of the photoreaction, and (2) a compound that generates an acid upon irradiation with actinic rays And a compound that crosslinks an alkali-soluble resin using an acid generated by light as a catalyst (acid-sensitive substance: hereinafter referred to as an “acid crosslinking agent”). . Among these, it is possible to provide a cross-linked chemically amplified resist that is excellent in compatibility with an alkali-soluble resin and has good sensitivity when combined with an alkali-soluble resin. A cross-linking component consisting of a combination is preferred.

<Photo acid generator>
The compound that generates an acid by actinic rays is not particularly limited as long as it is a substance that generates a Bronsted acid or a Lewis acid when exposed to activating radiation, and includes an onium salt, a halogenated organic compound, a quinonediazide compound, a sulfone. Known compounds such as compounds, organic acid ester compounds, organic acid amide compounds, and organic acid imide compounds can be used. Among these, aromatic sulfonic acid esters, aromatic iodonium salts, aromatic sulfonium salts, aromatic compounds having a halogenated alkyl residue, and the like are preferable. These photoacid generators are preferably selected from the viewpoint of spectral sensitivity in accordance with the wavelength of the light source that exposes the pattern.

  Examples of onium salts include diazonium salts, ammonium salts, iodonium salts such as diphenyliodonium triflate, sulfonium salts such as triphenylsulfonium triflate, phosphonium salts, arsonium salts, and oxonium salts.

  Halogenated organic compounds include halogen-containing oxadiazole compounds, halogen-containing triazine compounds, halogen-containing acetophenone compounds, halogen-containing benzophenone compounds, halogen-containing sulfoxide compounds, halogen-containing sulfone compounds, halogen-containing thiazole compounds. Halogen-containing oxazole compounds, halogen-containing triazole compounds, halogen-containing 2-pyrone compounds, other halogen-containing heterocyclic compounds, halogen-containing aliphatic hydrocarbon compounds, halogen-containing aromatic hydrocarbon compounds, sulfenyl halide compounds, etc. Is mentioned.

  Specific examples of the halogenated organic compound include tris (2,3-dibromopropyl) phosphate, tris (2,3-dibromo-3-chloropropyl) phosphate, tetrabromochlorobutane, 2- [2- (3,4). -Dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -S-triazine, 2- [2- (4-methoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -S-triazine, hexa Chlorobenzene, hexabromobenzene, hexabromocyclododecane, hexabromocyclododecene, hexabromobiphenyl, allyltribromophenyl ether, tetrachlorobisphenol A, tetrabromobisphenol A, bis (chloroethyl) ether of tetrachlorobisphenol A, tetrabromo Bisf Bis (bromoethyl) ether of diol A, bis (2,3-dichloropropyl) ether of bisphenol A, bis (2,3-dibromopropyl) ether of bisphenol A, bis (2,3-dichloropropyl) of tetrachlorobisphenol A ) Ether, bis (2,3-dibromopropyl) ether of tetrabromobisphenol A, tetrachlorobisphenol S, tetrabromobisphenol S, bis (chloroethyl) ether of tetrachlorobisphenol S, bis (bromoethyl) ether of tetrabromobisphenol S Bis (2,3-dichloropropyl) ether of bisphenol S, bis (2,3-dibromopropyl) ether of bisphenol S, tris (2,3-dibromopropyl) isocyanurate, 2,2- And halogen-based flame retardants such as bis (4-hydroxy-3,5-dibromophenyl) propane and 2,2-bis (4- (2-hydroxyethoxy) -3,5-dibromophenyl) propane; .

  Specific examples of the quinonediazide compound include 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,1 Sulfonic acid esters of quinonediazide derivatives such as naphthoquinonediazide-4-sulfonic acid ester, 2,1-benzoquinonediazide-5-sulfonic acid ester; 1,2-benzoquinone-2-diazide-4-sulfonic acid chloride, 1, 2-naphthoquinone-2-diazide-4-sulfonic acid chloride, 1,2-naphthoquinone-2-diazide-5-sulfonic acid chloride, 1,2-naphthoquinone-1-diazide-6-sulfonic acid chloride, 1,2- Benzoquinone-1-diazide-5-sulfonic acid chloride, etc. Sulfonic acid chloride quinonediazide derivative; and the like.

  Specific examples of the sulfone compounds include sulfone compounds and disulfone compounds having unsubstituted, symmetrically or asymmetrically substituted alkyl groups, alkenyl groups, aralkyl groups, aromatic groups, or heterocyclic groups.

  Examples of the organic acid ester include carboxylic acid ester, sulfonic acid ester, and phosphoric acid ester. Examples of the organic acid amide include carboxylic acid amide, sulfonic acid amide, and phosphoric acid amide. Examples thereof include carboxylic acid imide, sulfonic acid imide, and phosphoric acid imide.

  In addition, cyclohexylmethyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, dicyclohexyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, 2-oxocyclohexyl (2-norbornyl) sulfonium trifluoromethanesulfonate, 2-cyclohexylsulfonylcyclohexanone Dimethyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, triphenylsulfonium trifluoromethanesulfonate, diphenyliodonium trifluoromethanesulfonate, N-hydroxysuccinimide trifluoromethanesulfonate, phenylparatoluenesulfonate, and the like.

  The photoacid generator is usually used at a ratio of 0.1 to 10 parts by weight, preferably 0.3 to 8 parts by weight, more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the alkali-soluble resin. The If the ratio of the photoacid generator is too small or too large, the shape of the resist pattern may be deteriorated.

<Acid crosslinking agent>
An acid crosslinking agent is a compound (acid-sensitive substance) that can crosslink an alkali-soluble resin in the presence of an acid generated by irradiation (exposure) with actinic rays. Examples of such acid cross-linking agents include known acid cross-linking compounds such as alkoxymethylated urea resins, alkoxymethylated melamine resins, alkoxymethylated uron resins, alkoxymethylated glycoluril resins, and alkoxymethylated amino resins. Can be mentioned.

  In addition, as an acid crosslinking agent, alkyl etherified melamine resin, benzoguanamine resin, alkyl etherified benzoguanamine resin, urea resin, alkyl etherified urea resin, urethane-formaldehyde resin, resol type phenol formaldehyde resin, alkyl etherified resole type phenol formaldehyde Examples thereof include resins and epoxy resins.

  Among these, alkoxymethylated amino resins are preferable, and specific examples thereof include methoxymethylated amino resins, ethoxymethylated amino resins, n-propoxymethylated amino resins, and n-butoxymethylated amino resins. it can. Among these, methoxymethylated amino resins such as hexamethoxymethylmelamine are particularly preferable in terms of good resolution. Commercially available products of alkoxymethylated amino resins include, for example, PL-1170, PL-1174, UFR65, CYMEL300, CYMEL303 (manufactured by Mitsui Cytec), BX-4000, Nicalac MW-30, MX290 (and above, Sanwa) (Manufactured by Chemical Co., Ltd.).

  These acid crosslinking agents can be used alone or in combination of two or more. The acid crosslinking agent is generally used in a proportion of 0.5 to 60 parts by weight, preferably 1 to 50 parts by weight, and more preferably 2 to 40 parts by weight with respect to 100 parts by weight of the alkali-soluble resin. If the use ratio of the acid crosslinking agent is too small, it is difficult to sufficiently advance the crosslinking reaction, the residual film ratio of the resist pattern after development using an alkali developer is reduced, and the resist pattern is swollen or meandered. Deformation is likely to occur. If the proportion of the acid crosslinking agent used is too large, the resolution may be reduced.

<Ratio of photoacid generator and crosslinking agent>
From the viewpoint of improving the heat resistance of the resist pattern, the crosslinking component (b) is preferably a combination of a photoacid generator (b1) and an acid crosslinking agent (b2). The weight ratio (b1: b2) of the photoacid generator (b1) to the acid crosslinking agent (b2) is usually 1: 1 to 1:30, preferably 1: 2 to 1:25, more preferably 1: 3. ~ 1: 20. When the ratio between the two is within the above range, a high degree of heat resistance can be achieved.

  Furthermore, the weight ratio (b1: b2) of the photoacid generator (b1) to the acid crosslinking agent (b2) is preferably 1: 4 to 1:30, more preferably 1: 5 to 1:25, particularly preferably. When the lower limit of the ratio of the acid crosslinking agent (b2) to the photoacid generator (b1) is increased from 1: 6 to 1:20, the heat resistance of the resist pattern is further significantly improved. In many cases, a sufficiently high heat resistance can be achieved when the weight ratio (b1: b2) of both is in the range of 1: 7 to 1:15. In this case, the use ratio of the photoacid generator (b1) to 100 parts by weight of the alkali-soluble resin is preferably 1 to 10 parts by weight, more preferably 2 to 8 parts by weight, and the acid crosslinking agent to 100 parts by weight of the alkali-soluble resin. The use amount of (b2) is preferably 4 to 60 parts by weight, more preferably 8 to 50 parts by weight, and it is desirable to increase the lower limit of each use ratio.

3. Compounds that absorb actinic rays:
When a compound that absorbs actinic rays is contained in the resist composition, light that goes in the depth direction of the resist film is absorbed during exposure, so that a resist pattern having a reverse taper in cross section can be formed. The shape of the resist pattern is also affected by the reflected light reflected by the substrate and the ITO film formed on the substrate. Therefore, a compound that absorbs actinic rays is required for preventing reflection of exposure light. In particular, a photosensitive resin composition using a combination of a photoacid generator and an acid crosslinking agent as a crosslinking component is a crosslinked chemical amplification resist, and an acid generated by light irradiation diffuses in the resist film, In order to cause a crosslinking reaction even in a region not exposed to light, it is important to control the shape of the resist pattern by the presence of a compound that absorbs actinic rays.

  As the compound that absorbs actinic rays, a compound having an absorption region in the wavelength region may be selected according to the wavelength of the exposure light source. However, a compound having low solubility in an alkali developer tends to remain on the substrate after development. Therefore, a compound having an acidic residue such as a phenolic hydroxyl group, a carboxy group, or a sulfonyl group and having increased solubility in an alkali developer. preferable. For the purpose of solving the problem of residue generation, it is preferable to select a compound having higher absorbance so that sufficient absorbance can be obtained with a small addition amount. When the formed resist pattern is exposed to a high temperature in a post-exposure bake (PEB) or sputtering process, the compound may sublimate and contaminate the apparatus. Therefore, it is preferable to use a compound with low sublimability. .

  Examples of the compound that absorbs actinic rays used in the present invention include so-called azo dyes. Examples of the azo dye include azobenzene derivatives, azonaphthalene derivatives, azobenzene or azonaphthalene substituted arylpyrrolidone, and heterocyclic arylazo compounds such as pyrazolone, benzpyrazolone, pyrazole, imidazole, and thiazole.

  In these arylazo compounds, the length of the conjugated system, the type of substituent, and the like can be appropriately selected in order to set the absorption wavelength in a desired region. For example, by substituting with an electron-withdrawing group such as a sulfonic acid (metal salt) group, a sulfonic acid ester group, a sulfone group, a carboxy group, a cyano group, a (substituted) aryl or an alkylcarbonyl group, and a halogen, an absorption region in a short wavelength Can be used as an arylazo compound. Further, by substituting with an electron donating group such as amino group, hydroxy group, alkoxy group or aryloxy group substituted with (substituted) alkyl, (substituted) aryl or polyoxyalkylene, the absorption wavelength is in the long wavelength region. It can also be set as the arylazo compound set to (1). Since the substituent includes a group that decreases the solubility in an alkali developer such as an amino group and a group that increases the solubility in an alkali developer such as a carboxy group or a hydroxy group, the resist composition of the present invention. It is desirable to appropriately select the type of substituent of the arylazo compound so that the sensitivity of the above becomes a practical level.

  In the case of an azo dye, various compounds that absorb actinic rays in a wide wavelength region of 200 to 500 nm can be used by selecting the structure of the compound and the type of substituent. The selection of the length of the conjugated system and the substituent is applicable to compounds other than the azo dye. As a compound mainly corresponding to a light source in a wavelength region of 300 to 400 nm, a styrene derivative obtained by condensing (substituted) benzaldehyde and a compound having an active methylene group can be mentioned. Examples of the substituent of benzaldehyde include an alkylamino group substituted with hydroxy, alkoxy or halogen, a polyoxyalkyleneamino group, a hydroxy group, a halogen, an alkyl group, an alkoxy group, an alkyl or an arylcarbonyl group. Examples of the compound having an active methylene group include 1,3-diketones such as acetonitrile, α-cyanoacetate, α-cyanoketones, malonate, acetoacetate, and the like.

  As compounds that absorb actinic rays, natural dyes such as methine dyes obtained by condensing arylpyrazolones and arylaldehydes, arylbenzotriazoles, azomethine dyes obtained as condensates of amines and aldehydes, curcumin, xanthone, etc. A compound or the like can also be used. The development characteristics may be adjusted by using a compound that absorbs exposure light and simultaneously changes the solubility in an alkali developer or crosslinks, such as a quinonediazide sulfonate esterified dye of an arylhydroxy group or a bisazide compound.

  Further, examples of the compound that absorbs actinic rays include cyanovinylstyrene compounds, 1-cyano-2- (4-dialkylaminophenyl) ethylenes, p- (halogen-substituted phenylazo) -dialkylaminobenzenes, 1-alkoxy. -4- (4'-N, N-dialkylaminophenylazo) benzenes, dialkylamino compounds, 1,2-dicyanoethylene, 9-cyanoanthracene, 9-anthrylmethylenemalononitrile, N-ethyl-3-carba Zolylmethylenemalononitrile, 2- (3,3-dicyano-2-propenylidene) -3-methyl-1,3-thiazoline and the like can be used.

  Among the commercially available dyes, useful compounds that absorb actinic rays include, for example, oil yellow # 101, oil yellow # 103, oil yellow # 117, oil pink # 312, oil green BG, oil blue BOS, and oil. Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (manufactured by Orient Chemical Co., Ltd.), Crystal Violet (C.I. 42555), Methyl Violet (C.I. 42535), Rhodamine B ( CI 45170B), malachite green (CI 42000), methylene blue (CI 52015), and the like.

  Specific examples of the 1-cyano-2- (4-dialkylaminophenyl) ethylenes include 1-carboxy-1-cyano-2- (4-di-n-hexylaminophenyl) ethylene, 1-carboxy- 1-cyano-2- (4-di-n-butylaminophenyl) ethylene, 1-carboxy-1-cyano-2- (4-di-n-heptylaminophenyl) ethylene has a carboxyl group at the 1-position Examples include 1-cyano-2- (4-dialkylaminophenyl) ethylenes.

  These 1-cyano-2- (4-dialkylaminophenyl) ethylenes, oil yellow # 101, oil yellow # 103, oil yellow # 107 and the like are excellent in the formation of a reverse tapered resist pattern profile.

  In the present invention, it is preferable to use a bisazide compound having an azide group at both ends as a compound that absorbs actinic rays. By using a bisazide compound, a resist pattern having good heat resistance can be easily formed without causing a protrusion-like shape abnormality on the side wall. As the bisazide compound, those that absorb actinic rays in a wavelength range of 200 to 500 nm are preferable.

  Examples of the bisazide compound include 4,4′-diazidochalcone, 2,6-bis (4′-azidobenzal) cyclohexanone, 2,6-bis (4′-azidobenzal) -4-methylcyclohexanone, 2,6- Bis (4′-azidobenzal) -4-ethylcyclohexanone, sodium 4,4′-diazidostilbene-2,2′-disulfonate, 4,4′-diazidodiphenyl sulfide, 4,4′-diazidobenzophenone, 4,4'-diazidodiphenyl, 2,7-diazidofluorene, 4,4'-diazidophenylmethane.

  Examples of commercially available bisazide compounds include trade names BAC-H, BAC-M, BAC-E, DAC, DAz, ST (Na), DazST (51), and DazBA (Na) manufactured by Toyo Gosei Co., Ltd. The bisazide compounds can be used alone or in combination of two or more.

  The compound that absorbs actinic rays is usually 0.1 to 10 parts by weight, preferably 0.3 to 8 parts by weight, more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the alkali-soluble resin. Used. If the amount of the compound used is too small, the effect of improving the shape of the pattern sidewall becomes small, and if it is too large, it becomes difficult to form a pattern having a reverse tapered cross section. In general, when the resist film thickness is thick, it is difficult for light to pass through. Therefore, the amount of the compound that absorbs actinic rays may be relatively small, and when it is thin, it is preferable to use a relatively large amount.

4). Polyvinyl alkyl ether:
The polyvinyl alkyl ether used in the present invention is a polymer of vinyl ether CH ₂ ═CHOR (R is an alkyl group), and is a polymer material generally called polyvinyl ether. R is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group.

The polyvinyl alkyl ether can be synthesized by polymerizing vinyl ether using a cationic polymerization initiator. Among the polyvinyl alkyl ethers, polyvinyl methyl ether (R = CH ₃ ) is particularly preferable because it is easily available and has a good effect of improving adhesion.

  The polyvinyl alkyl ether is usually used in a proportion of 0.01 to 10 parts by weight, preferably 0.05 to 8 parts by weight, more preferably 0.1 to 5 parts by weight, with respect to 100 parts by weight of the alkali-soluble resin. If the blending ratio of the polyvinyl alkyl ether is too small, the effect of improving the adhesion of the resist pattern to the substrate is reduced. When the blending ratio of the polyvinyl alkyl ether is too large, the surface hardness of the resist coating film is lowered due to the plasticizing effect, and the resist pattern is easily damaged.

5). Other additives:
A surfactant can be added for the purpose of improving the dispersibility of each component constituting the photosensitive resin composition. Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenol ether, and other polyoxyethylene alkyl ethers. Oxyethylene aryl ethers; polyethylene glycol dialkyl esters such as polyethylene glycol dilaurate and ethylene glycol distearate; Ink), Florard FC430, FC431 (Sumitomo 3M), Asahi Guard AG710, Surflon S-382, S Fluorine surfactants such as C-101, SC-102, SC-103, SC-104, SC-105, SC-106 (Asahi Glass Co., Ltd.); organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); acrylic acid type Or methacrylic acid (co) polymer polyflow No. 75, no. 95 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.). The amount of these surfactants to be added is usually 2 parts by weight or less, preferably 1 part by weight or less per 100 parts by weight of the solid content of the photosensitive resin composition.

6). Organic solvent:
The photosensitive resin composition of the present invention is usually used as a solution obtained by dissolving each component in an organic solvent and filtering. The organic solvent is used in an amount sufficient to uniformly dissolve or disperse each component. The solid content concentration in the solution is usually about 5 to 50% by weight, preferably about 10 to 40% by weight.

  Examples of the organic solvent used in the present invention include alcohols such as n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, and cyclohexyl alcohol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone. Propyl formate, butyl formate, ethyl acetate, propyl acetate, butyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl lactate, ethyl lactate, ethyl ethoxypropionate, ethyl pyruvate, etc. Esters; Cyclic ethers such as tetrahydrofuran and dioxane; Cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; Ethyl cellosolve acetate, propyl cellosolve acetate, buty Cellosolve acetates such as cellosolve acetate; Alcohol ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether; Propylene glycol, propylene glycol monomethyl ether acetate, propylene glycol monoethyl acetate, propylene glycol Propylene glycols such as monobutyl ether; Diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether and diethylene glycol diethyl ether; Lactones such as γ-butyrolactone; Halogenated hydrocarbons such as trichloroethylene Aromatics such as toluene and xylene; polar organic solvents such as dimethylacetamide, dimethylformamide, and N-methylacetamide; mixed solvents of two or more of these.

7). Nitrogen-containing basic compounds:
In the present invention, it is preferable to add a nitrogen-containing basic compound in order to improve the storage stability of the photosensitive resin composition. Examples of nitrogen-containing basic compounds include aliphatic primary amines, aliphatic secondary amines, aliphatic tertiary amines, amino alcohols, aromatic amines, quaternary ammonium hydroxides, and alicyclic amines. It is done.

  Specific examples of the nitrogen-containing basic compound include butylamine, hexylamine, ethanolamine, triethanolamine, 2-ethylhexylamine, 2-ethylhexyloxypropylamine, methoxypropylamine, diethylaminopropylamine, N-methylaniline, N- Ethylaniline, N-propylaniline, dimethyl-N-methylaniline, diethyl-N-methylaniline, diisopropyl-N-dimethylaniline, N-methylaminophenol, N-ethylaminophenol, N, N-dimethylaniline, N, N-diethylaniline, N, N-dimethylaminophenol, tetrabutylammonium hydroxide, tetramethylammonium hydroxide, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,5 Diazabicyclo [4.3.0] non-5-ene, and the like.

  The nitrogen-containing basic compound is usually used in a proportion of 0.01 to 10 parts by weight, preferably 0.1 to 8 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the alkali-soluble resin. It is done. When the use ratio of the nitrogen-containing basic compound is too small, the effect of improving the storage stability is reduced, and when it is too large, the effect of improving the storage stability is saturated and the resist characteristics may be adversely affected.

8). Method for using photosensitive resin composition:
The photosensitive resin composition of the present invention is uniformly coated on a substrate by a coating method such as spin coating, and when the solvent is removed by drying, a resist film is formed on the substrate. This resist film is generally heat-treated (prebaked) at a heating temperature of about 80 to 110 ° C. for a time of about 10 to 200 seconds. In this way, a resist film having a thickness of usually about 0.5 to 5 μm is obtained.

  In order to form a resist pattern, first, the resist film is exposed in a pattern using a desired light source. When the photosensitive resin composition of the present invention is a cross-linked chemically amplified resist material containing a photoacid generator and an acid cross-linking agent as cross-linking components, it is usually 100 after exposure for the purpose of accelerating the cross-linking reaction. Heat treatment (PEB) is performed at a temperature of about ~ 130 ° C for a time of about 10 to 200 seconds.

  Examples of actinic rays used for exposure include ultraviolet rays, far ultraviolet rays, KrF excimer laser light, X-rays, and electron beams. Specific examples of the light source to be exposed include an emission line spectrum of mercury such as 436 nm, 405 nm, 365 nm, and 254 nm, and a 248 nm KrF excimer laser light source.

  The substrate is not particularly limited, and examples thereof include a silicon substrate, a glass substrate, an ITO film formation substrate (ITO substrate), a chromium film formation substrate, and a resin substrate. Since the photosensitive resin composition of this invention is excellent in the adhesiveness with respect to a board | substrate, it shows the outstanding adhesiveness also with respect to the ITO board | substrate for organic EL display elements with extremely small surface roughness.

  The photosensitive resin composition of the present invention functions as a negative resist in which the exposed portion becomes insoluble or hardly soluble in an alkaline developer due to the action of the crosslinking component. Begins to remain on the substrate. The exposure energy at this time is referred to as Eth.

  The photosensitive resin composition of the present invention can be developed with an alkaline developer. In general, an alkaline aqueous solution is used as the alkaline developer. Examples of the alkali include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium silicate and ammonia; primary amines such as ethylamine and propylamine; secondary amines such as diethylamine and dipropylamine; trimethylamine and triethylamine Tertiary amines such as; alcohol amines such as diethylethanolamine and triethanolamine; quaternary such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide Ammonium hydroxides; and the like. If necessary, a water-soluble organic solvent such as methyl alcohol, ethyl alcohol, propyl alcohol, and ethylene glycol, a surfactant, a resin dissolution inhibitor, and the like can be added to the alkaline aqueous solution.

  When the resist pattern obtained by development is used in the lift-off method, various films such as a metal vapor deposition film are formed on the entire surface of the resist pattern. Thereafter, the resist pattern is removed together with the film formed thereon to leave a film such as a metal vapor deposition film formed on the substrate. When producing an organic EL display element, an organic EL material is vapor-deposited on the resist pattern obtained by development, and then a metal such as aluminum is vapor-deposited. In this case, the resist pattern is left without being removed.

  If the resist pattern formed on the substrate is irradiated with ultraviolet rays while being heated before such a vapor deposition step, the heat resistance of the resist pattern can be further improved. Specifically, the entire substrate is placed on a hot plate and irradiated with ultraviolet rays at an irradiation dose of about 5 to 1000 mW while being heated to a temperature of about 70 to 120 ° C. The irradiation time of ultraviolet rays is usually about 20 to 40 seconds.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. The physical properties are measured as follows.

(1) Adhesion:
A photosensitive resin composition was spin-coated on an ITO substrate for an organic EL display element or an ITO substrate for an LCD, and then baked on a hot plate at 110 ° C. for 90 seconds to form a coating film having a thickness of 3 μm. Using a 20 μm line & space (L & S) pattern mask, a parallel light aligner (Canon, PLA501F)
And exposed. The exposure amount was an energy amount at which the line and space portions were 1: 1. After exposure, the exposed portion was crosslinked by baking (PEB) on a hot plate at 110 ° C. for 60 seconds.

  As for the surface roughness (unit: nm) of the ITO substrate for organic EL display elements, the standard deviation Rms in the height direction is 1.13, the three-dimensional surface roughness Ra is 0.90, the highest value-the lowest value (height) Rmax represented by (direction) was 16.14. On the other hand, as for the surface roughness (unit: nm) of the ITO substrate for LCD, the standard deviation Rms in the height direction is 5.89, the three-dimensional surface roughness Ra is 4.69, the highest value-the lowest value (height direction). ) Represented by R) was 53.27.

  After PEB, paddle development was performed for 70 seconds with a 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution to obtain an L & S pattern. An optical microscope was used to confirm whether the developed line pattern remained, and when all remained, it was evaluated as A, and when there was a remaining part, it was evaluated as B.

(2) Storage stability:
The photosensitive resin composition was stored at 5 ° C. and 23 ° C. for 3 months, and the sensitivity (Eth) was measured. Based on the sensitivity of the photosensitive resin composition stored at 5 ° C., the sensitivity change of the photosensitive resin composition stored at 23 ° C. is within 5%, A is within 5-10%, B is 10 % And those where insolubles were generated were evaluated as C.

(3) Sensitivity measurement method:
After a photosensitive resin composition was spin-coated on a silicon wafer, it was baked on a hot plate at 110 ° C. for 90 seconds to form a film having a thickness of 1.95 μm. Using a g-line stepper (NSR1505G6E), 100 pieces of 5 mm square patterns were exposed while changing the exposure amount at regular intervals. After the exposure, the exposed portion was crosslinked by baking (PEB) on a hot plate at 110 ° C. for 60 seconds. After PEB, paddle development was performed for 70 seconds with a 2.38 wt% TMAH aqueous solution, and the exposure amount at which the resist film began to remain in the exposed portion was defined as sensitivity (Eth).

[Example 1]
60 parts by weight of poly p-vinylphenol (trade name “Marcalinker S-2P”, manufactured by Maruzen Kasei Co., Ltd.) having a weight average molecular weight (Mw) of 5000 and m-cresol / p-cresol of 70/30 (weight ratio) With respect to 100 parts by weight of an alkali-soluble resin comprising 40 parts by weight of a novolak resin having a weight average molecular weight of 4000 obtained by dehydration condensation with formaldehyde at a charging ratio, a triazine photoacid generator (trade name “TAZ110, manufactured by Midori Chemical Co., Ltd.) is used. 2) parts by weight, 20 parts by weight of a melamine-based crosslinking agent (acid crosslinking agent: trade name “Cymel 303” manufactured by Mitsui Cytec Co., Ltd.), 1 weight by weight of a bisazide compound (trade name “BAC-M” manufactured by Toyo Gosei Co., Ltd.) Parts and polyvinyl methyl ether (BASF Dispersion, trade name “Lunator M-40”) 0.2 parts by weight in polyethylene glycol Dissolved in monomethyl ether (PGMEA) 290 parts by weight. The obtained solution was filtered through a polytetrafluoroethylene membrane filter having a pore diameter of 0.1 μm to prepare a resist solution.

  Using this resist solution, a resist pattern was formed on the ITO substrate for organic EL display element and the ITO substrate for LCD by the above-described procedure, and an adhesion test was performed. The cross-sectional shapes of the patterns were all reversely tapered. Moreover, storage stability was evaluated by the above method using this resist solution. The results are shown in Table 1.

[Examples 2-3]
The same operation as in Example 1 was carried out except that the blending ratio of polyvinyl methyl ether was changed as shown in Table 1. The cross-sectional shapes of the patterns were all reversely tapered. The results are shown in Table 1.

[Comparative Example 1]
The same operation as in Example 1 was performed except that polyvinyl methyl ether was not blended. The results are shown in Table 1.

[Comparative Example 2]
The same operation as in Example 1 was carried out except that hexamethyldisilazane (CH ₃ ) ₃ Si—NH—Si (CH ₃ ) ₃ was added instead of polyvinyl methyl ether. The results are shown in Table 1.

[Comparative Example 3]
The same operation as in Example 1 was performed except that bisphenol type epoxy resin (manufactured by JER, trade name “Epicoat 1001”) was added in place of polyvinyl methyl ether. The results are shown in Table 1.

  As is clear from the results in Table 1, the photosensitive resin compositions (Examples 1 to 3) of the present invention all have a reverse tapered cross-sectional shape and are excellent in heat resistance, and in addition to organic EL. A resist pattern having excellent adhesion to the ITO substrate for display elements and the ITO substrate for LCD can be formed, and the storage stability is good.

  On the other hand, the photosensitive resin composition containing no polyvinyl methyl ether (Comparative Example 1) has a reverse tapered cross-sectional shape, excellent heat resistance, and good adhesion to an ITO substrate for LCD. However, the adhesiveness with respect to the ITO substrate for organic EL display elements with high smoothness was inadequate.

  Moreover, the photosensitive resin composition (Comparative Examples 2-3) which added the hexamethyldisilazane which is a well-known additive for improving adhesiveness, or an epoxy resin is the ITO substrate for organic EL display elements, and ITO for LCD Although the adhesion to the substrate was both excellent, the storage stability was poor.

  The photosensitive resin composition of the present invention is suitably used as an electrically insulating partition wall forming material in an organic electroluminescence display panel (organic EL display element) or a resist material for pattern formation having a reverse taper cross section by a lift-off method. can do.

FIG. 1 is an explanatory diagram showing an example of a pattern formation process by a lift-off method. FIG. 2 is an explanatory view showing an example of fine processing of the organic EL display panel. FIG. 3 is a cross-sectional view showing an example of a microfabricated organic EL display panel. FIG. 4 is a cross-sectional view showing a resist pattern whose cross section is an overhang. FIG. 5 is an explanatory diagram showing an example of a pattern formation process by a lift-off method using a resist pattern having a forward tapered cross section.

Explanation of symbols

1: substrate, 2: resist pattern (cross section), 3, 3 ′: metal vapor deposition film,
21: Transparent substrate, 22: ITO film, 23: Resist pattern (cross section),
24, 24 ': vapor deposition film of organic EL material, 25, 25': metal vapor deposition film,
31: Transparent substrate, 32: ITO film, 33: Resist pattern (cross section),
34a, 34b, 34c: vapor deposition film of organic EL material,
35, 35 ': metal deposition film, 41: substrate, 42: resist pattern (cross section),
43: Overhang portion, 51: Substrate, 52: Resist pattern (cross section),
53: Metal vapor deposition film.

Claims (5)

  An alkali-soluble resin (a), a crosslinking component (b) that crosslinks the alkali-soluble resin by irradiation with actinic rays or actinic rays and subsequent heat treatment, a compound (c) that absorbs actinic rays, and a polyvinyl alkyl ether (d) Photosensitive resin composition to contain.   The photosensitive resin composition according to claim 1, wherein the polyvinyl alkyl ether (d) is polyvinyl methyl ether.   The photosensitive resin composition according to claim 1 or 2, wherein the blending ratio of the polyvinyl alkyl ether (d) is 0.01 to 10 parts by weight with respect to 100 parts by weight of the alkali-soluble resin (a).   The photosensitive resin composition according to any one of claims 1 to 3, wherein the alkali-soluble resin (a) contains 30 to 95% by weight of polyvinylphenol and 5 to 70% by weight of a novolac resin.   On a substrate, an alkali-soluble resin (a), a crosslinking component (b) that crosslinks the alkali-soluble resin by irradiation with actinic rays or actinic rays followed by heat treatment, a compound (c) that absorbs actinic rays, and a polyvinyl alkyl ether A pattern forming method comprising a step of forming a resist film comprising a photosensitive resin composition containing (d), exposing the resist film in a pattern, and developing the resist film with an alkaline developer.

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