Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/18—Homopolymers or copolymers of aromatic monomers containing elements other than carbon and hydrogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L61/00—Compositions of condensation polymers of aldehydes or ketones; Compositions of derivatives of such polymers
  • C08L61/04—Condensation polymers of aldehydes or ketones with phenols only
  • C08L61/06—Condensation polymers of aldehydes or ketones with phenols only of aldehydes with phenols

Definitions

• the present invention relates to a resist composition used in the photolithography technology field, and more particularly, to a resist pattern having a cross section of an inversely tapered shape or an overhang shape, and having a remarkable heat resistance. And a resist composition which is improved.
• the resist composition of the present invention is particularly suitable for use as, for example, a negative resist for forming a pattern by a lift-off method, a photoresist for forming an electrically insulating partition in an organic electroluminescent display panel, and the like.
• a resist material capable of forming a resist pattern profile having an inverted tapered cross section or an overhang section may be required. Specific examples include a case where a pattern is formed by a lift-off method and a case where an electrically insulating partition of an organic electroluminescent display panel is formed.
• the lift-off method is applied to, for example, formation of a conductor pattern, formation of a thermal head heating element, and correction of a white defect in a photomask.
• a conductor pattern is formed by a lift-off method
• (1) a resist film is formed on a substrate, and (2) the resist film is exposed in a pattern and developed to form a negative resist pattern.
• (4) Dip the entire substrate in a solution to form a negative resist pattern. Swelling dissolved
• the conductor pattern is formed on the substrate through a series of steps. In the above step (4), the deposited film on the negative resist pattern is also removed, and the deposited film on the substrate remains in a pattern.
• step (2) as shown in FIG. 1, if a negative resist pattern 2 having a reverse tapered 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). Then, a vapor deposition film 3 and a vapor deposition film 3 ′ are formed on the substrate 1 and the negative resist pattern 2 independently. Therefore, if the negative resist pattern 2 is removed in the step (4), the deposited film 3 ′ thereon is also removed, and only the pattern of the deposited film 3 remains on the substrate 1.
• the resist pattern profile has a cross-sectional shape such as a rectangular shape, a forward tapered shape, and a squeezed shape
• step (3) if a metal vapor-deposited film is formed on the entire substrate, a vapor-deposited film is also formed on the side of the resist pattern Therefore, the deposited film on the substrate and the deposited film on the resist pattern are formed continuously. Therefore, if the resist pattern is removed in the step (4), not only the deposited film formed thereon but also a part or the whole of the deposited film on the substrate which is continuous therewith will be peeled off.
• organic EL luminescence (hereinafter abbreviated as “organic EL”) displays are self-luminous, have no restriction on viewing angle, have high brightness, can make panels thin, can be driven at low voltage, It has features such as fast response speed and full color with three primary colors of RGB (red, blue and green). Have. However, since organic EL materials have low resistance to organic solvents, they cannot be etched, and there has been a problem that it is difficult to form a matrix structure as a display element by microfabrication using photolithography technology. Therefore, organic EL displays were mainly used as backlights for liquid crystal displays.
• Japanese Patent Application Laid-Open No. 8-315981 proposes a new proposal regarding a technology for forming a display element using an organic EL material.
• a plurality of strip-like patterns made of indium tin oxide (ITO) are formed on a transparent substrate to form a first display electrode (anode), and (2) a first display electrode (anode).
• ITO indium tin oxide
• PEB postexposurebaking
• the negative resist pattern plays the role of an electrically insulating partition. That is, as shown in FIG. 2, a stripe-shaped patterned ITO film (anode) 22 is formed on a transparent substrate 21, and then a striped negative resist pattern 23 orthogonal to this is formed. Form. If the cross section of this negative resist pattern is reverse tapered or overhung, when the organic EL material is vapor-deposited on the negative resist pattern, a stripe-shaped organic EL material orthogonal to the IT ⁇ film 22 is formed on the substrate 21.
• the deposition film 24 is formed independently. Even if 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.
• Independent metal vapor-deposited films 25 and 25 ' are formed on the organic EL material vapor-deposited film 24 and the organic EL material vapor-deposited film 24' on the negative resist pattern, respectively.
• the metal deposition film 25 formed on the deposition film 24 of the organic EL material becomes the second display electrode (cathode). Adjacent second display electrodes (cathodes) are separated by a negative resist pattern and are electrically insulated.
• the ITO film (anode) 22 and the metal-deposited film (cathode) 25 are separated by the organic EL material-deposited film 24 and do not short-circuit.
• the organic EL materials of each color are sequentially deposited using a deposition mask during the deposition of the organic EL materials, the organic EL materials of each color are deposited on the transparent substrate 31 and the ITO film 32 as shown in FIG. Films 34a (R), 34b (G), and 34c (B) are formed.
• Films 34a (R), 34b (G), and 34c (B) are formed.
• an organic EL material deposited film is hardly formed thereon.
• metal vapor-deposited films 35 and 35 ' are formed independently on the vapor-deposited film of the organic EL material of each color and on the negative resist pattern.
• the first display electrode and the second display electrode intersect, and the vapor-deposited film portion of the organic EL material sandwiched between the two electrodes serves as a light emitting portion.
• the negative resist pattern is not removed and remains as an electrically insulating partition.
• Japanese Patent Application Laid-Open No. 5-165818 discloses that (A) a component which is cross-linked by exposure to a light beam or a heat treatment following exposure, and (B) an alkali-soluble component.
• a negative resist composition containing at least one kind of a compound which absorbs light and (C) a light beam to be exposed to light, and uses an aqueous solution of a developer as a developing solution.
• this negative resist composition is used, a reverse tapered or overhang resist pattern suitable for the lift-off method can be formed.
• the formation of a metal deposition film by the lift-off method is performed at a high temperature.
• the electrically insulating partition walls of the organic EL display panel must maintain its shape to withstand the organic EL material deposition and metal deposition processes under high temperature conditions.
• it is required to improve the heat resistance of an electrically insulating partition wall composed of a resist pattern in order to increase the margin (tolerance) of the sublimation temperature.
• organic EL display panels are used in mobile devices and on-vehicle devices, they must be durable enough to withstand high-temperature conditions such as elevated temperatures in vehicles.
• the conventional resist pattern having a reverse tapered or overhanging cross section has a problem in that heat resistance is not yet sufficient. Disclosure of the invention
• An object of the present invention is to provide a resist composition capable of forming a resist pattern having a reverse tapered or overhanging cross section, and providing a resist pattern having significantly improved heat resistance.
• Another object of the present invention is to provide a method for forming a resist pattern on a substrate using such a resist composition.
• the present inventors have conducted intensive studies to achieve the above object, and found that (A) an alkali-soluble resin, (B) actinic ray irradiation (exposure), or actinic ray irradiation and subsequent heat treatment. Contains a component that crosslinks the resoluble resin (crosslinking component) and (C) a compound that absorbs actinic rays (exposure rays)
• A an alkali-soluble resin
• A) a combination of polyvinyl phenol and nopolak resin in a specific ratio as the alkali-soluble resin a resist pattern having a reverse tapered or overhanging cross section can be formed, It has been found that the resist pattern has good
• the crosslinking component (B) a compound (B1) that generates an acid upon irradiation with actinic rays and a compound (B2) that crosslinks an alkali-soluble resin using the acid as a catalyst are used in combination, and By increasing the ratio of the compound (B2) to the compound (B1), the heat resistance of the resist pattern can be further improved.
• the resist composition of the present invention can be alkali-developed and can form a negative resist pattern having a reverse tapered or overhanging cross section.
• the resist composition of the present invention is suitably applied to a lift-off method or the like. However, if desired, the exposure amount can be adjusted to variously change the cross-sectional shape of the resist pattern. It can also be used as a bird.
• the present invention has been completed based on these findings.
• an alkali-soluble resin (B) a component that bridges an alkali-soluble resin by irradiation with actinic light, or irradiation with actinic light and subsequent heat treatment, and (C) an actinic ray
• a resist composition containing a compound to be absorbed wherein (A) the alkali-soluble resin is a resin composition containing 30 to 95% by weight of polyvinylphenol and 5 to 70% by weight of a novolak resin.
• a resist composition is provided.
• a resist comprising the resist composition on a substrate.
• a pattern forming method comprising the steps of: forming a resist film, exposing the resist film in a pattern, and developing the resist film with an alkali developing solution.
• FIG. 1 is an explanatory diagram illustrating an example of a pattern forming process by a lift-off method.
• FIG. 2 is an explanatory diagram showing an example of fine processing of an 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 having a cross section of an overhang type.
• a resin composition containing 30 to 95% by weight of polyvinylphenol and 5 to 70% by weight of a nopolak resin is used as the alkali-soluble resin.
• an alkali-soluble resin for example, a nopolak resin obtained by addition-condensation of m-creso-r-no-p-cresol (weight ratio: 80:20 to 20:80) and formaldehyde is used.
• a nopolak resin obtained by addition-condensation of m-creso-r-no-p-cresol (weight ratio: 80:20 to 20:80) and formaldehyde is used.
• a nopolak resin When a nopolak resin is used as the alkali-soluble resin, an inversely tapered resist pattern can be obtained, but the heat resistance of the obtained resist pattern is not sufficient, and the result is 120 to 130.
• the present inventors have found that even a resist composition using a nopolak resin as an alkali-soluble resin, heats a resist pattern formed on a substrate. It has been found that the heat resistance temperature can be improved to about 150 ° C. by irradiating ultraviolet rays while performing the irradiation. However, the deposition temperature of the organic EL material sometimes requires a heat resistance temperature exceeding the temperature. On the other hand, a resist composition using polyvinyl phenol as an alkali-soluble resin has a problem that the resist pattern is easily peeled off from the substrate after the resist pattern is formed, and a metal or organic EL material is deposited on the resist pattern. In the technical field, it was difficult to use.
• the present inventors have surprisingly found that the combined use of polyvinylphenol and novolak resin as alkali-soluble resins suppresses peeling of the resist pattern from the substrate and increases the heat resistance temperature. We found that it could be significantly improved.
• polyvinyl phenol examples include a homopolymer of vinyl phenol and a copolymer of vinyl phenol and a monomer copolymerizable therewith.
• monomers copolymerizable with vinyl phenol include isopropyl phenol, acrylic acid, methacrylic acid, styrene, maleic anhydride, maleic acid imide, and vinyl acetate.
• homopolymers of vinylphenol are preferred, and homopolymers of p-vinylphenol are particularly preferred.
• the average molecular weight of polyvinyl phenol is a weight average molecular weight (Mw) in terms of monodisperse polystyrene measured by gel permeation chromatography (GPC), and is usually from 3,000 to 200,000, preferably. Is from 4,000 to 15,500, more preferably from 5,000 to 10,0,000. If the weight average molecular weight of the polyvinyl phenol is too low, the molecular weight does not sufficiently increase even if the exposed region undergoes a cross-linking reaction, so that the polyvinyl phenol is easily dissolved in an alkali developing solution, and the effect of improving heat resistance is reduced.
• Mw weight average molecular weight in terms of monodisperse polystyrene measured by gel permeation chromatography
• the novolak resin those widely used in the technical field of resist can be used.
• the nopolak resin can be obtained, for example, by reacting phenols with aldehydes or ketones in the presence of an acidic catalyst (for example, oxalic acid).
• phenols include phenol, orthocresol, methyl cresol, 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-Methoxy 5- Rufuenoru, 2-t - Bed Chiru 5-methyl phenol, thymol, Ru is like Isochimoru. These can be used alone or in combination of two or more.
• aldehydes examples include formaldehyde, formalin, paraformaldehyde, trioxane, acetoaldehyde, propyl aldehyde, benzaldehyde, phenylacetaldehyde, ⁇ -phenylpropyl aldehyde, / 3-phenylphenyl aldehyde, and ⁇ -hydroxy.
• Ketones include acetone, methyl ethyl ketone, getyl ketone, diphenyl ketone and the like. These can be used alone or in combination of two or more.
• a novolak resin in which meta-cresol and para-cresol are used in combination and formaldehyde, formalin, or paraformaldehyde is condensed with these is particularly preferred from the viewpoint of the sensitivity control of the resist.
• the charged weight ratio of meta-cresol to para-cresol is usually 80:20 to 20:80, preferably 70:30 to 50:50. It is also preferred to use 3,5-dimethylphenol (ie, 3,5-xylenol). In this case, the weight ratio of cresols (total amount of methcresol and paracresol) to 3,5-xylenol is usually 50:50 to 80:20, preferably 60:40. ⁇ 70: 30.
• the average molecular weight of the nopolak resin is a weight average molecular weight in terms of monodisperse polystyrene measured by GPC, and is usually from 1,000 to 10,000, preferably from 2,000 to 7,0. 0, more preferably 2,500 to 6,000. If the weight-average molecular weight of the nopolak resin is too low, the effect of increasing the molecular weight is small even if a cross-linking reaction occurs in the exposed area, and the resin is easily dissolved in an alkali developer. If the weight-average molecular weight of the nopolak resin is too high, the difference in solubility between exposed and unexposed portions in the developer is small, making it difficult to obtain a good resist pattern.
• the weight average molecular weight of the polyvinyl phenol and the nopolak resin can be controlled in a desired range by adjusting the synthesis conditions.
• a method in which a resin obtained by synthesis is pulverized and solid-liquid extraction is performed with an organic solvent having appropriate solubility The weight average molecular weight can be controlled by, for example, dissolving in a solvent and dropping it into a poor solvent, or dropping the poor solvent to perform solid-liquid or liquid-liquid extraction.
• the measurement of the weight-average molecular weight by GPC is performed under the following conditions using a SC820 (manufactured by TOS O) as a GPC measurement device.
• Sample 0.1 ml of a sample having a concentration of 0.05 to 0.6% by weight was injected.
• the use ratio of the polyvinyl phenol and the novolak resin in terms of weight ratio is usually 30:70 to 95: 5, preferably 35:65 to 95: 5, more preferably 40:60. ⁇ 90: 10 range.
• the ratio of polyvinyl phenol increases, the heat resistance of the resist pattern improves, but the resist pattern is easily peeled off from the substrate.
• the proportion of the nopolak resin increases, the problem of peeling of the resist pattern from the substrate is solved, but the heat resistance is reduced. Therefore, when the ratio between the two is within the above range, the balance between the heat resistance and the peeling resistance is improved.
• the crosslinking component (B) used in the present invention is a component that crosslinks the soluble resin by irradiation with actinic rays or irradiation with actinic rays and subsequent heat treatment.
• the resist composition of the present invention functions as a negative resist that can be developed with an alkali developing solution.
• Photopolymerization initiator for example, benzophenone derivative, benzoin derivative, benzoin ether derivative, etc.
• a compound having an unsaturated hydrocarbon group which is polymerized by the radical for example, Penno erythritol tetra (meth) acrylate
• a combination with a sensitizer to enhance the efficiency of the photoreaction and (2) a compound capable of generating an acid upon irradiation with actinic rays (hereinafter referred to as a “photoacid generator”).
• Examples thereof include a combination with a compound (acid-sensitive substance: hereinafter, referred to as a “crosslinking agent”) which crosslinks an aqueous soluble resin using an acid generated by light as a catalyst.
• a crosslinking agent which crosslinks an aqueous soluble resin using an acid generated by light as a catalyst.
• the photoacid of (2) is excellent in that it can provide a cross-linked chemically amplified resist having excellent sensitivity when combined with an alkali-soluble resin and having excellent compatibility with an alkali-soluble resin.
• a crosslinking component comprising a combination of the generator (B1) and the crosslinking agent (B2) is preferred.
• the compound that generates an acid by actinic rays is not particularly limited as long as it is a substance that generates a Brenstead acid or a Lewis acid when exposed to activating radiation.
• aromatic sulfonates preferred are aromatic sulfonates, aromatic odonium salts, aromatic sulfonium salts, and aromatic compounds having a halogenated alkyl residue.
• aromatic sulfonates preferred are aromatic sulfonates, aromatic odonium salts, aromatic sulfonium salts, and aromatic compounds having a halogenated alkyl residue.
• photoacid generators are preferably selected from the viewpoint of spectral sensitivity according to the wavelength of the light source for exposing the pattern.
• sodium salts include diazonium salts, ammonium salts, rhododium salts such as diphenyl eodonium triflate, sulfonium salts such as triphenylsulfonium triflate, phosphonium salts, and arsonium. Pum salt and oxonium salt.
• halogenated organic compound examples include halogen-containing oxaziazole-based compounds, halogen-containing triazine-based compounds, halogen-containing acetophenone-based compounds, halogen-containing benzophenone-based compounds, halogen-containing sulfoxide-based compounds, halogen-containing sulfone-based 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, and halogen-containing fragrances Group hydrocarbon compounds and sulfenyl halide compounds.
• halogenated organic compound examples include tris (2,3-dibromopropyl) phosphate, tris (2,3-dibromo-3-cyclopropyl) phosphate, tetrabromochlorobutane, 2— [2 ⁇ (3 , 4—Dimethoxyphenyl) ethenyl] —4,6-bis (trichloromethyl) _S—triazine, hexacyclobenzene benzene, hexabromobenzene, hexabole mocyclododecane, hexabole mocyclododecene, hexabromobiphenyl , Aryl tribromophenyl ether, tetrachlorobisphenol 8, tetrabromobisphenol A, bis (chloroethyl) ether of tetrachlorobisphenol A, bis (bromoethyl) ether of tetrabrom
• quinonediazide compound examples include 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazido4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,1 Mono-naphthoquinonediazide 4-sulfonic acid ester, 2,1-benzoquinonediazidosulfonic acid ester of a quinonediazide derivative such as 5-sulfonic acid ester; 1,2-benzoquinone-2-diazide-14-sulfonic acid chloride, 1,2-naphthoquinone- 1 2-diazido 4-sulfonic acid chloride, 1,2-naphthoquinone_2-diazide-5-sulfonic acid chloride, 1,2-naphthoquinone-l-diazido 6-sulfonic acid chloride And 1,2-benzoquinon
• ⁇ '-bis (sulfonyl) diazomethane compounds include unsubstituted, symmetrically or asymmetrically substituted alkyl, alkenyl, A, a'-bis (sulfonyl) diazomethane having an aralkyl group, an aromatic group, or a heterocyclic group;
• ⁇ -sulfonyldiazomethane compounds include unsubstituted, symmetrically or asymmetrically substituted alkyl, alkenyl, aralkyl, aromatic, and heterocyclic compounds. And monocyclic ⁇ -sulfonyldiazomethane having a cyclic group.
• the sulfone compound include a sulfone compound and a disulfone compound having an unsubstituted, symmetrically or asymmetrically substituted alkyl group, alkenyl group, aralkyl group, aromatic group, or heterocyclic group. I can do it.
• organic acid esters include carboxylic acid esters, sulfonic acid esters, and phosphoric acid esters.
• organic acid amides include carboxylic acid amides, sulfonic acid amides, and phosphoric acid amides.
• the acid imide include a carboxylic acid imide, a sulfonic acid imide, and a phosphoric acid imide.
• cyclohexylmethyl (2-oxocyclohexyl) sulfonium trifluoromethane sulfonate dicyclohexyl (2-year-old cyclohexyl) sulfonium trifluoromethane sulfonate, 2-oxocyclohexyl Xyl (2-norpornyl) sulfonium trifluoromethane sulfonate, 2-cyclohexylsulfonylcyclohexanone, dimethyl (2-cyclohexylhexyl) sulfonium trifluoromethyl sulfonate, triphenyl sulfonium trifluoromethane Methanesulfonate, diphenyl trifluoromethane sulfonate, ⁇ -hydroxysuccinimide trifluoromethane sulfonate, phenyl paratoluene sulf
• the photoacid generator is usually used in an amount of 0.1 to 10 parts by weight, preferably 0.3 to 8 parts by weight, more preferably 0.5 to 100 parts by weight of the alkali-soluble resin. Used in proportions of up to 5 parts by weight. If the proportion of the photoacid generator is too small or too large, the shape of the resist pattern may be deteriorated.
• the cross-linking agent is a compound (acid-sensitive substance) that can cross-link the alkali-soluble resin in the presence of an acid generated by irradiation (exposure) of actinic rays.
• a crosslinking agent include well-known acid crosslinking compounds such as an alkoxymethylated urea resin, an alkoxymethylated melamine resin, an alkoxymethylated perone resin, an alkoxymethylated daryl glycol peril resin, and an alkoxymethylated amino resin. Can be mentioned.
• alkyl etherified melamine resin benzoguanamine resin, alkyl etherified benzoguanamine resin, urea resin, alkyl etherified urea resin, urethane-formaldehyde resin, resole-type phenol-formaldehyde resin, alkyl-etherified-resole-type phenol-formaldehyde resin And epoxy resins.
• alkoxymethylated amino resins are preferred, and specific examples thereof include methoxymethylated amino resins, ethoxymethylated amino resins, n-propoxymethylated amino resins, and n-butoxymethylated amino resins. Can be. Among these, a methoxymethylated amino resin such as hexamethoxymethylmelamine is particularly preferred in that the resolution is good.
• Commercially available alkoxymethylated amino resins include PL-1170, PL-1174, UFR65, CYMEL300, CYMEL303 (all manufactured by Mitsui Cytec), BX-4 00, two-strength rack MW-30, MX290 (all manufactured by Sanwa Chemical Co., Ltd.) and the like.
• crosslinking agents can be used alone or in combination of two or more.
• the crosslinking agent is usually 0.5 to 60 parts by weight, preferably 1 to 50 parts by weight, based on 100 parts by weight of the alkali-soluble resin. It is preferably used in a proportion of 2 to 40 parts by weight. If the amount of the cross-linking agent used is too small, it becomes difficult for the cross-linking reaction to proceed sufficiently, and the residual film ratio of the resist pattern after development using an alkali developing solution is reduced, and the resist pattern swells and deforms such as meandering. Is more likely to occur. If the amount of the crosslinking agent is too large, the resolution may be reduced.
• the weight ratio (B1: B2) of the photoacid generator (B1) to the crosslinking agent (B2) is usually 1: 1 to 1:30, preferably 1: 2 to 1:25, and more preferably. Is 1: 3 to 1:20. When the ratio of the two is within the above range, higher heat resistance than the conventional level can be achieved.
• the weight ratio (B1: B2) of the photoacid generator (B1) to the crosslinking agent (B2) is preferably 1: 4 to 1:30, more preferably 1: 3.
• the lower limit of the ratio of the crosslinking agent (B2) to the photoacid generator (B1) was increased to 5 to 1:25, particularly preferably 1: 6 to 1:20, the heat resistance of the resist pattern was reduced. It has been found that the improvement is even more remarkable. In many cases, a sufficiently high heat resistance can be achieved when the weight ratio (B1: B2) of the two is in the range of 1: 7 to 1:15.
• 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 100% by weight of the alkali-soluble resin.
• the amount of the crosslinking agent (B2) to be used is preferably 4 to 60 parts by weight, more preferably 8 to 50 parts by weight, and the lower limit of each use ratio is desirably increased.
• the resist composition contains a compound that absorbs actinic rays, it absorbs light that goes in the depth direction of the resist film during exposure, so the cross section is inversely tapered. A one- or overhang resist pattern can be obtained.
• the shape of the resist pattern is also affected by the light reflected by the substrate and the ITO film formed on the substrate being reflected. Therefore, the component (C) is also required to prevent reflection of exposure light.
• a resist composition using a combination of a photoacid generator and a crosslinking agent as the component (B) is a cross-linked chemically amplified resist in which the acid generated by light irradiation diffuses in the resist film.
• a cross-linking reaction occurs even in a region not exposed to light, it is important to control the shape of the resist pattern by the presence of the component (C) that absorbs active light.
• a compound having an absorption region in the wavelength region may be selected according to the wavelength of the exposure light source.
• the component (C) is a compound having low solubility in an alkali developing solution, the component (C) tends to remain on the substrate after development, so that a phenolic hydroxyl group, a carboxy group, a sulfonyl group, etc.
• Compounds which impart an acidic residue of (1) to increase the solubility in an alkaline developer are preferred.
• component (C) may sublime and contaminate the equipment. It is preferable that the compound has low sublimability.
• the component (C) used in the present invention is preferably a so-called azo dye.
• the azo dye include azobenzene derivatives, azonaphthylene derivative, azobenzene or azonaphthylene substituted arylpyrrolidone, and heterocyclic arylazo compounds such as pyrazolone, benzpyrazolone, pyrazolyl, imidazole, and thiazole. Is mentioned.
• the length of the conjugated system, the type of the substituent, and the like can be appropriately selected in order to set the absorption wavelength in a desired region.
• An example For example, by substituting a sulfonic acid (metal salt) group, sulfonic ester group, sulfone group, carboxy group, cyano group, (substituted) aryl or alkylcarbonyl group, or an electron-withdrawing group such as halogen, the absorption wavelength in a short wavelength is reduced. It can be an arylazo compound having a defined area.
• the absorption wavelength can be increased by substituting an electron-donating group such as an amino group, a hydroxy group, an alkoxy group, or an aryloxy group substituted with (substituted) alkyl, (substituted) aryl or polyoxyalkylene.
• An arylazo compound set in the wavelength region can also be used.
• substituents There are two types of substituents: a group that reduces solubility in an alkaline developer, such as an amino group, and a group that increases the solubility in an alkaline developer, such as a carboxyl group-hydroxy group. It is desirable to appropriately select the type of the substituent of the arylazo compound so that the sensitivity of the resist composition of the present invention becomes a practical level.
• azo dyes various compounds that absorb actinic light in a wide wavelength range 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 substituents also applies to compounds other than azo dyes.
• the compound mainly corresponding to a light source in a wavelength region of 300 to 400 nm include a styrene derivative obtained by condensing (substituted) benzaldehyde with a compound having an active methylene group.
• Examples of the substituent of benzaldehyde include an alkylamino group, a polyoxyalkyleneamino group, a hydroxy group, a halogen, an alkyl group, an alkoxy group, an alkyl group and an arylcarbonyl group substituted with a hydroxy, alkoxy or halogen.
• Examples of the compound having an active methylene group include 1,3-diketones such as acetonitrile, ⁇ -monocyanoacetate, polycyanoketones, malonate, and acetoacetate.
• methine dyes obtained by condensing arylpyrazolone and arylaldehyde, arylbenzotriazoles, and An azomethine dye obtained as a condensate of a min and an aldehyde, a natural compound such as curcumin or xanthone, or the like can also be used.
• Developing properties are adjusted using compounds that absorb exposure light and change solubility in an alkaline developer at the same time as exposure to light, such as bis-azide compounds, such as quinonediazide sulfonic acid ester of dyes having aryloxy groups. May be.
• component (C) for example, cyanovinylstyrene-based compounds, 1-cyano-12- (4-dialkylaminophenyl) ethylenes, p_ (halogen-substituted phenylazo) dialkylaminobenzenes, 1- Alkoxy 41 (4'-N, N-dialkylaminophenylazo) Benzenes, dialkylamino compounds, 1,2-dicyanethylene, 9-cyanoanthracene, 9-anthrylmethylenemalononitrile, N —Ethyl-3—Luvazolylmethylenemalononitrile, 2- (3,3-dicyan-2-propylidene) -1,3-methyl-1,3-thiazoline, etc. can be used.
• the component (C) useful as the component (C) are, for example, Oil Yellow # 101, Oil Yellow # 103, Oil Yellow # # 117, Oil Pink # 31 2.
• 1-cyano-2- (4-dialkylaminophenyl) ethylenes specifically, 1-carboxy-1-cyano 2- (4-di-n-hexylaminophenyl) ethylene, 1-carboxy-1 —Siano— 2- (4-di-n-butylaminophenyl) ethylene, 1-carboxy-1-cyano-2- (4-di-n-heptylaminophenyl) ethylene, etc. — 2- (4-alkylaminophenyl) ethylenes.
• the amount of the component (C) used can be appropriately determined according to the thickness of the resist composition, the type of the component (C), and the like. Although it is possible, in general, when the film thickness is large, it may be relatively small because light is difficult to transmit, and when the film thickness is small, it is used relatively frequently.
• Component (C) is usually 0.1 to 15 parts by weight, preferably 0.5 to 10 parts by weight, particularly preferably 1 to 8 parts by weight, based on 100 parts by weight of the alkali-soluble resin. Used in proportion.
• Surfactants can be added to the resist composition for the purpose of improving the dispersibility of each component of the resist composition.
• the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether, and polyoxyethylene nonyl phenyl ether.
• Polyoxyethylene aryl ethers such as norether; polyethylene dalicol dialkyl esters such as polyethylene glycol dilaurate and ethylene glycol distearate; EFTOP EF301, EF303, EF355 ( Shin-Akita Kasei Co., Ltd.), Megafax F171, F172, F173, F177 (manufactured by Dainippon Ink), Florado FC430, FC4311 (Sumitomo Suri) -Am), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, Fluorosurfactant such as SC-106 (made by Asahi Glass Co., Ltd.); Organosiloxane polymer KP341 (made by Shin-Etsu Chemical Co., Ltd.); Acrylic or methacrylic acid (co) polymer polyflow No 75, No.
• the amount of these surfactants 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 resist composition.
• the resist composition of the present invention may be used as a powder, if desired, but is usually used as a resist solution obtained by dissolving each component in an organic solvent and filtering.
• the organic solvent is used in an amount sufficient to dissolve or disperse each component uniformly.
• the solid content concentration in the resist solution is usually about 5 to 50% by weight, preferably about 10 to 40% by weight.
• organic solvent examples include alcohols such as n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, cyclohexyl alcohol; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentone, and cyclohexanone And other ketones; 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, pyrvin Esters such as acid ethyl; cyclic ethers such as tetrahydrofuran, dioxane; etc .; Cell solvents such as methyl sorb, ethyl solvent, butyl sorb and the like;
• the resist composition of the present invention is uniformly applied on a substrate by an application method such as spin coating, and when the solvent is dried and removed, a resist film is formed on the substrate.
• the resist film is generally subjected to a heat treatment (prebaking) at a temperature of about 80 to 110 ⁇ 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 mm is obtained.
• prebaking a heat treatment
• a resist film is exposed in a pattern using a desired light source.
• the resist composition of the present invention is (II) a crosslinked chemically amplified resist containing a photoacid generator and a crosslinking agent as components, it is usually 100 ⁇ m after exposure for the purpose of accelerating the crosslinking reaction.
• ⁇ 130X about temperature, about 10 ⁇ 200 seconds time, heat treatment (postexposurebaking: P EB) fr.
• the 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 a mercury emission line spectrum of 436 nm, 405 nm, 365 nm, and 254 nm, and a 1 ⁇ 1 "F excimer laser of 24811111.
• Light sources, etc. I can do it.
• the substrate is not particularly limited, and examples thereof include a silicon substrate, a glass substrate, an IT film forming substrate, a chromium film forming substrate, and a resin substrate.
• the exposed portion is substantially insolubilized in an alkali developing solution by the action of a cross-linking component and functions as a negative type resist. Begin to remain on top. The exposure energy at this time is called Eth.
• a resist pattern having a reverse tapered or overhanging cross section is usually obtained at an exposure dose of about twice or less of E th. As the exposure is increased, the cross-sectional shape of the resist pattern becomes a forward taper shape.
• the resist composition of the present invention can be developed with an alkaline developer.
• an aqueous alkali solution is usually used.
• 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 getylamine and dipropylamine; trimethylamine.
• tertiary amines such as triethylamine; alcoholamines such as getylethanolamine and triethanolamine; tetramethylammonium hydroxide, tetraethylammonium hydroxide and triethylhydroxymethylammonium.
• Quaternary ammonium hydroxides such as droxide and trimethylhydroxyethylammonium hydroxide; and the like.
• a water-soluble organic solvent such as methyl alcohol, ethyl alcohol, propyl alcohol, and ethylene glycol, a surfactant, and a resin dissolution inhibitor can be added to the aqueous alkali solution.
• the resist pattern obtained by the development is used for the lift-off method
• various films such as a metal deposition film are formed on the entire surface of the substrate from above. Then, the resist pattern is removed together with the film formed thereon, and the substrate is removed. A film such as a metal vapor-deposited film formed thereon is left.
• an organic EL material is deposited on the resist pattern obtained by development, and then a metal such as aluminum is deposited. In this case, the resist pattern is left without being removed.
• the heat resistance of the resist pattern can be further improved.
• the entire substrate is placed on a hot plate and irradiated with ultraviolet rays at a radiation dose of about 5 to 100 OmW 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.
• the substrate on which the resist pattern had been formed was placed on a hot plate for 30 seconds, and the temperature at which the reverse tapered resist pattern could be maintained was measured. Specifically, the resist pattern was heated for 30 seconds every 110 ° C to 5 ° C, and the shape of the resist pattern was observed using a scanning electron microscope. The temperature at the time when the reverse tapered shape could not be maintained was measured.
• m-Cresol Zp-Cresol 90 parts by weight of poly p-vinylphenol having a weight average molecular weight of 6,000, m-Cresol Zp-Cresol was prepared by dehydration-condensing with formaldehyde at a charge ratio of 70/30 (weight ratio) and 10 parts by weight of a novolak resin having a weight average molecular weight of 4,000.
• a resist solution was applied to the ITO substrate with the ITO film formed on the glass substrate using Subinco overnight, and then pre-baked at 90 ° C for 90 seconds to obtain a resist having a thickness of 4 A film was formed.
• parallel line Taraina one manufactured by Canon Inc., P LA 5 0 1 F
• a test reticle was exposed with an exposure amount 2 0 0 m JZ cm 2.
• a post-exposure bake (PEB) was performed at 110 for 60 seconds.
• the resist pattern (LZS-20 / im reverse taper) was developed by using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide by a paddle method at 23 for 70 seconds. ) was formed. Table 1 shows the measurement results.
• a resist pattern was formed on a substrate in the same manner as in Example 1 except that the proportions of polyvinyl phenol and nopolak resin used were changed as shown in Table 1. Table 1 shows the measurement results.
• a resist pattern was formed on a substrate in the same manner as in Example 1 except that the polyvinylphenol used in Example 1 was used alone as the soluble resin. Table 1 shows the measurement results.
• Example 2 A resist pattern was formed on a substrate in the same manner as in Example 1 except that the novolak resin used in Example 1 was used alone as the alkali-soluble resin. Table 1 shows the measurement results.
• a resist solution was prepared in the same manner as in Example 3, except that 1 part by weight of the triazine photoacid generator was changed to 3 parts by weight, and 3 parts by weight of the melamine resin crosslinking agent was changed to 25 parts by weight. And a resist pattern Formed. As a result, the heat resistance temperature of the resist pattern was improved from 200 ° C. in Example 3 to 300 ° C. This resist pattern also had good peeling resistance ( ⁇ ).
• Example 4 The procedure of Example 4 was repeated except that 1 part by weight of the triazine photoacid generator was changed to 3 parts by weight, and 3 parts by weight of the melamine resin crosslinking agent was changed to 25 parts by weight. A solution was prepared, and a resist pattern was formed. As a result, the heat-resistant temperature of the resist pattern was improved from 180 in Example 4 to 27 Ot :. This resist pattern also had good peeling resistance ( ⁇ ). Industrial applicability
• a resist composition capable of forming a resist pattern having a reverse tapered or overhanging cross section, and having significantly improved heat resistance of the resist pattern.
• the resist composition of the present invention is particularly suitable for use as, for example, a negative resist for forming a pattern by a lift-off method, a photoresist for forming an electrically insulating partition in an organic electroluminescence display panel, and the like.

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