JP4403174B2 - Pattern forming method and photosensitive resin composition used therefor - Google Patents

Description

  The present invention relates to a photoresist composition. In particular, the present invention relates to a photoresist composition suitable for application by slit coating.

  Conventionally, a photoresist for patterning a driving circuit for a liquid crystal display is generally manufactured by discharging a photosensitive resin composition to the central portion of a glass and applying it by spin rotation, followed by pre-baking and drying. . However, the coating method has changed due to the increase in the size of the substrate and the reduction in the amount of resist, and the method of spin-rotating and further pre-baking drying after slit coating has come to be used. When spin rotation becomes difficult due to a demand for further increase in the size of the substrate, a manufacturing method in which, after slit coating, drying under reduced pressure and further pre-baking drying is used.

  The spin rotation performed after slit coating is intended to evaporate a part of the solvent contained in the coating film and to make the coating film uniform. Therefore, in the method in which spin rotation is performed after slit coating, coating uniformity is maintained by spin rotation. However, in the method of drying under reduced pressure after slit coating, it is impossible to make the coating film uniform by spin rotation, so the coating film after slit coating needs to be uniform. However, according to the study by the present inventors, it has been difficult to make the coating film immediately after slit coating sufficiently uniform even if the conventionally used photosensitive resin composition is used as it is. Furthermore, in the subsequent drying under reduced pressure, a problem that marks such as chucks and pins for fixing the substrate after coating remain on the film surface is likely to occur.

  The conditions of vacuum drying performed after slit coating are various, but basically a method of suddenly reducing the pressure from about 101 kPa (atmospheric pressure) to about 20 Pa at about 30 seconds under room temperature is used. There are many. In order to apply such relatively severe vacuum drying conditions, it is necessary to adjust the degree of drying of the coating film. If the degree of drying of the coating film is not appropriate, a large problem will occur in the pattern shape and coating properties, causing various troubles.

  As a solvent used in such a photosensitive resin composition, the vapor pressure of propylene glycol monomethyl ether acetate (hereinafter sometimes referred to as PGMEA) generally used is about 500 Pa at 20 ° C./1 atm. It is very easy to evaporate during drying under reduced pressure. As a result, PGMEA rapidly evaporates from the surface of the coated film after application, a dry film is formed in the vicinity of the surface, and evaporation of PGMEA inside the coated film is prevented. When a pattern is formed using such a resist film, the vicinity of the surface of the resist film is difficult to be developed, and the inside is easily developed. Therefore, the pattern shape is a reverse taper shape (also referred to as T-top). The corners of the pattern remain during post-baking, which may cause peeling defects. Also, the resist pattern is insufficiently dried, resulting in insufficient etching resistance. In some cases, the metal wiring formed in this way becomes non-uniform.

  In pattern formation using a positive photoresist, when developing an exposed resist film, the photosensitive agent and the resin are azo-bonded when an unexposed portion comes into contact with the developer, and an alkaline developer It is generally known that the contrast between the exposed area and the unexposed area can be achieved by reducing the solubility. In the conventional method in which the photosensitive composition is dried under reduced pressure after slit coating, the surface of the unexposed area is relatively less soluble in the alkali developer than the inside due to the drying of the coating surface. For this reason, the contrast tends to be too strong. In order to solve such a problem, for example, the addition of a low-molecular resin component having high reactivity with a photosensitizer called a contrast enhancer is not performed, and the amount of the photosensitizer is reduced. However, although such a method has a certain improvement effect with respect to the pattern shape, there are problems such as insufficient amount of photosensitizer and variation in pattern width, and lack of contrast enhancer, resulting in lower actual contrast. There was something to do.

  On the other hand, in order to suppress coating unevenness when a photosensitive resin composition is applied to form a resist film, mixing a plurality of solvents has been studied. For example, Patent Document 1 discloses a photosensitive resin composition using diethylene glycol dialkyl ether, ethyl 3-ethoxypropionate, alkyl acetate, and alkyl lactate as a solvent. The photosensitive resin composition described in Patent Document 1 is intended to improve lateral stripe unevenness, vertical stripe unevenness, and amorphous unevenness on the entire surface of a substrate. Such a combination of solvents considers the evaporation rate, but the evaporation rate is at the time of application, and does not consider the evaporation rate in reduced-pressure drying or the like. For this reason, as far as the present inventors know, there is room for improvement in order to solve the problems at the time of drying under reduced pressure as described above.

Patent Document 2 describes a photosensitive resin composition containing benzyl alcohol. The benzyl alcohol used here is used by mixing with a main solvent such as propylene glycol monomethyl ether acetate in order to improve coating unevenness. However, in this patent document, a method using a spin coating method is described exclusively as a coating method, and there is no description about the problem in slit coating that involves drying under reduced pressure as described above.
JP 2006-171670 A International Patent Publication No. 2004/095142 Pamphlet

  As described above, according to the study by the present inventors, when a photosensitive resin composition containing propylene glycol monomethyl ether acetate, which is generally used as a solvent, is used, uneven coating and uniform coating during coating are used. In addition, there is room for improvement in the properties, and since the surface of the coating film is easier to dry than the inside, the pattern shape is reversely tapered, resulting in poor peeling and excessive contrast. Therefore, means for solving these problems has been demanded.

The pattern forming method according to the present invention includes an alkali-soluble resin, a photosensitizer, and a mixed solvent, and the mixed solvent includes propylene glycol monomethyl ether acetate and a co-solvent having a vapor pressure of 150 Pa or less at 1 atm and 20 ° C. A photosensitive resin composition is applied on a substrate by a slit coating method to form a coating film,
The formed coating film is dried under reduced pressure,
Followed by heat drying to evaporate and remove at least a portion of the solvent,
Imagewise exposure to the desired pattern,
Develop to form a pattern,
The method includes heating and curing the developed pattern.

  The photosensitive resin composition for slit coating according to the present invention comprises an alkali-soluble resin, a photosensitizer, and a mixed solvent. The mixed solvent is propylene glycol monomethyl ether acetate and the vapor pressure at 1 atm and 20 ° C is 150 Pa or less. And a co-solvent.

  According to the present invention, it is possible to improve uneven coating and non-uniformity of coating at the time of coating, and further improve peeling defects and non-uniformity of line width by making the pattern shape formed into a preferable tapered shape. can do. To improve the pattern shape, there is no problem such as variation in pattern width as in the conventional methods of reducing the amount of photosensitizer and reducing the contrast enhancer.

  The photosensitive resin composition used in the pattern forming method according to the present invention comprises an alkali-soluble resin, a photosensitive agent, and a mixed solvent as essential components. The photosensitive resin composition used in the pattern forming method according to the present invention can be either a positive type or a negative type by adjusting the components of the photosensitive composition according to the use of the pattern to be formed. .

  Here, the mixed solvent is composed of propylene glycol monomethyl ether acetate and a co-solvent. Here, as the co-solvent, one having a vapor pressure measured at 1 atm of 20 ° C. of 150 Pa or less, preferably 100 Pa or less is used. Further, the lower limit of the vapor pressure of the co-solvent is not particularly limited, but the vapor pressure measured at 1 atm and 20 ° C. is generally 5 Pa or more, preferably 10 Pa or more, more preferably 15 Pa or more. If the vapor pressure of the co-solvent is lower than this range, it will be difficult to adjust the drying conditions in vacuum drying, or it will not be sufficiently dried by vacuum drying and subsequent pre-baking, and the solvent will remain in the resist film. It is necessary to be careful because it may be done. Cosolvents satisfying such conditions can be appropriately selected according to the type of other solid components contained in the photosensitive resin composition, the use of the photosensitive resin composition, the conditions for application or drying, and the like. it can.

  Preferable examples of such a cosolvent include alcohols, esters, ethers, glycol ethers and the like. Specific examples of preferred co-solvents include benzyl alcohol, ethylene glycol butyl ether acetate, more specifically ethylene glycol n- / iso- / sec- / tert-butyl ether acetate, propylene glycol, propylene glycol diacetate, propylene glycol monoalkyl. Ether (alkyl group having 4 to 5 carbon atoms), dipropylene glycol dialkyl ether (alkyl group having 1 to 5 carbon atoms), dipropylene glycol monoalkyl ether (alkyl group having 1 to 5 carbon atoms) diethylene glycol dialkyl ether (The alkyl group has 2 to 5 carbon atoms), diethylene glycol monoalkyl ether (the alkyl group has 1 to 5 carbon atoms), ethyl 3-ethoxypropionate, 3-methoxy-3-methylbutyl Seteto, 3-methoxy-3-methyl butanol, include those selected from the group consisting of butyl lactate and mixtures thereof.

  In addition, although benzyl alcohol is one of the preferable ones as a co-solvent, the coating property can be further improved by combining with another co-solvent to obtain a three-component mixed solvent. Examples of such a preferable three-component mixed solvent include a mixed solvent of PGMEA, benzyl alcohol, and ethylene glycol n-butyl ether acetate. The two-component mixed solvent of PGMEA and benzyl alcohol tends to be slightly inferior in applicability as compared with the above three-component mixed solvent.

  In the present invention, such a co-solvent and PGMEA are mixed to form a mixed solvent. The mixing ratio of the mixed solvent is not particularly limited, but the content of the cosolvent is preferably 5 to 70% by weight, preferably 5 to 60% by weight, based on the weight of the entire mixed solvent. At this time, when a co-solvent having high volatility, that is, a high vapor pressure is used, it is preferable that the content of the co-solvent is relatively large. The remaining portion is preferably only PGMEA, but may contain other solvents, for example, a solvent having a vapor pressure measured at 1 atm of 20 ° C. exceeding 150 Pa, as long as the effects of the present invention are not impaired. Good. In the present invention, the mixed solvent is not necessarily used as a mixture of PGMEA and a co-solvent, and PGMEA and the co-solvent are added separately when preparing the photosensitive resin composition. May be mixed in the composition.

  In addition, when a mixed solvent in which a co-solvent having a vapor pressure of more than 150 Pa at 1 atm and 20 ° C. and PGMEA are used, the coating characteristics of the photosensitive resin composition may be improved, but drying under reduced pressure may be observed. Sometimes it is difficult to sufficiently suppress the drying of the film surface. Furthermore, since the film surface is dried, film loss is unlikely to occur at the time of development, and the remaining film rate is close to 100%, and the pattern shape tends to be reverse tapered. In contrast, a solvent having a vapor pressure of 150 Pa or less as a co-solvent is difficult to dry by pre-baking. Therefore, in the conventional spin coating method, there is a decrease in the remaining film ratio due to the addition, but even in this case, when combined with reduced pressure drying, drying of the film surface can be suppressed even under sudden reduced pressure. In addition, the remaining film rate can be maintained.

  As the alkali-soluble resin that can be used in the pattern forming method according to the present invention, any conventionally known resin can be used. Specific examples include novolak resins, polymers having a silazane structure, acrylic polymers, silanol silicone, and polyimide. Of these, phenolic novolak resins such as phenol resins, particularly cresol novolak resins and xylenol novolak resins are preferred.

  Here, the phenolic novolak resin is a novolak type phenol resin obtained by polycondensation of at least one kind of phenols with aldehydes such as formalin.

  Examples of the phenols used for producing such a phenolic novolak resin include cresols such as o-cresol, p-cresol and m-cresol, 3,5-xylenol, 2,5-xylenol, 2, Xylenols such as 3-xylenol and 3,4-xylenol, 2,3,4-trimethylphenol, 2,3,5-trimethylphenol, 2,4,5-trimethylphenol, 3,4,5-trimethylphenol and the like Trimethylphenols, 2-t-butylphenol, 3-t-butylphenol, 4-t-butylphenol and other t-butylphenols, 2-methoxyphenol, 3-methoxyphenol, 4-methoxyphenol, 2,3-dimethoxyphenol 2,5-dimethoxyphenol, 3, -Methoxyphenols such as dimethoxyphenol, 2-ethylphenol, 3-ethylphenol, 4-ethylphenol, 2,3-diethylphenol, 3,5-diethylphenol, 2,3,5-triethylphenol, 3,4 Ethylphenols such as 1,5-triethylphenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, chlorophenols such as 2,3-dichlorophenol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, Resorcinols such as 5-methylresorcinol, catechols such as 5-methylcatechol, pyrogallols such as 5-methylpyrogalol, bisphenols such as bisphenol A, B, C, D, E, F, 2,6-dimethylol- p-cresol Methylolated cresols of, alpha-naphthol, naphthol such β- naphthol and the like. These are used alone or as a mixture of plural kinds.

  In addition to formalin, examples of aldehydes include salicylaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, chloroacetaldehyde, and the like. These may be used alone or as a mixture of plural kinds.

  The content of the alkali-soluble resin is not particularly limited, but is generally 5 to 25% by weight, preferably 7 to 20% by weight, based on the total weight of the photosensitive resin composition. If the range is lower than this range, it is necessary to apply the composition thickly in order to obtain a final resist film having a constant film thickness, and the flow inside the coating film tends to occur, and coating unevenness may occur. On the other hand, when the content of the resin is higher than this range, it is necessary to apply the composition thinly, and the film thickness uniformity may be insufficient. Therefore, care must be taken when the resin content is outside the above range.

  The photosensitizer used in the pattern forming method according to the present invention can be arbitrarily selected from those generally used, and a photosensitizer containing a quinonediazide group is preferable. Such a photosensitizer was obtained by reacting naphthoquinone diazide sulfonic acid chloride, benzoquinone diazide sulfonic acid chloride, and the like with a low molecular compound or a high molecular compound having a functional group capable of condensation reaction with these acid chlorides. Compounds. Here, examples of the functional group capable of condensing with an acid chloride include a hydroxyl group and an amino group, and a hydroxyl group is particularly preferred. Examples of the compound that can be condensed with an acid chloride containing a hydroxyl group include hydroquinone, resorcin, 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,4,4 '-Trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,2 ', 3,4,6'-pentahydroxybenzophenone, etc. Hydroxyphenyl alkanes such as hydroxybenzophenones, bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) propane, 4,4 ′ , 3 ", 4" -tetrahydroxy-3,5,3 ', 5 -Mentioning hydroxytriphenylmethanes such as tetramethyltriphenylmethane, 4,4 ', 2 ", 3", 4 "-pentahydroxy-3,5,3', 5'-tetramethyltriphenylmethane These may be used alone or in combination of two or more.

  Examples of acid chlorides such as naphthoquinone diazide sulfonic acid chloride and benzoquinone diazide sulfonic acid chloride include 1,2-naphthoquinone diazide-5-sulfonyl chloride, 1,2-naphthoquinone diazide-4-sulfonyl chloride, and the like. Can be mentioned. The amount of the photosensitizer containing a quinonediazide group is usually 5 to 50 parts by weight, preferably 10 to 40 parts by weight per 100 parts by weight of the alkali-soluble resin. If it is less than this, sufficient sensitivity as a photosensitive tree composition may not be obtained, and if it is more than this, a problem of precipitation of components may occur.

  The photosensitive resin composition used in the pattern forming method according to the present invention contains the above-mentioned mixed solvent, alkali-soluble resin, and photosensitive agent as essential components, but may further contain a surfactant. The surfactant is intended to maintain the uniformity of the photosensitive resin composition and improve the coating property. In particular, when a photosensitive resin composition is applied to a substrate, a scale-like pattern (hereinafter referred to as “urocomula”) may be generated on the surface. A surfactant is added to the photosensitive resin composition according to the present invention. This urocomula is suppressed by using. It is particularly preferable to use a nonionic surfactant in the photosensitive resin composition of the present invention. Nonionic surfactants include fluorine-based surfactants, silicon-based surfactants, hydrocarbon-based surfactants and the like, and it is particularly preferable to use fluorine-based surfactants. These surfactants are usually added in an amount of 200 to 10,000 ppm based on 1 part by weight of the total amount of the alkali-soluble resin and the photosensitizer. If the surfactant content is too high, problems such as poor development may occur.

  The photosensitive resin composition used in the pattern forming method according to the present invention can also contain an additional additive, for example, an adhesion assistant such as a contrast enhancer, an epoxy compound, or a silicon-containing compound, if necessary. Such an additive is selected from any conventionally known additives as long as the effects of the present invention are not impaired.

  The photosensitive resin composition used in the pattern forming method according to the present invention is used for coating by a slit coating method (sometimes referred to as a slot coating method or a spinless coating method). It can also be used for dip coating. Further, when used in a pattern forming method in which a slit coating method and reduced-pressure drying are combined, the effect of the present invention is strongly expressed. When a photoresist composition is applied onto a substrate by this slit coating method, the photoresist composition is generally stored in a supply container and then applied onto the substrate via a pipe and a nozzle of an application device. The photosensitive resin composition according to the present invention can apply an excellent coating film free of film peeling and coating unevenness at high speed by this slit coating method.

  The substrate on which the photoresist film is formed by slit coating using the photosensitive resin composition according to the present invention can then be processed by the same method as before. In general, at least a part of the solvent is removed under reduced pressure or vacuum conditions, and further, the solvent is removed by baking as necessary, imagewise exposure to a desired pattern, development, and heating to form a photoresist film. Is cured. In the step of removing the solvent, it is not always necessary to remove all the solvent from the coating film, and it may be removed to the extent that it does not become an obstacle in the subsequent steps. These treatments are arbitrarily selected according to the application of the resist pattern to be produced, the type of the photosensitive resin composition, and the like.

  The photoresist pattern manufactured by such a method can be used for manufacturing various electronic components. In the photoresist film, since the uniformity of the film surface is particularly important, the pattern forming method of the present invention is advantageous for producing an electronic component having excellent performance, for example, a semiconductor element. Further, it can be particularly preferably used in fields where it is required to form a photoresist film on a relatively large substrate by slit coating or the like, for example, in the production of a liquid crystal display.

  The present invention will be described with reference to examples.

Example 1
An esterified product of 2,3,4,4′-tetrahydroxybenzophenone and 1,2-naphthoquinonediazide-5-sulfonyl chloride is used as a photosensitizer for 100 parts by weight of novolak resin having a weight average molecular weight of 8,000 in terms of polystyrene. 25 parts by weight, fluorosurfactant, MegaFac R-08 (Dainippon Ink Chemical Co., Ltd. nonionic surfactant) was added at 1000 ppm to the total solid content, and propylene glycol monomethyl ether acetate and ethylene glycol n- A mixed solvent (mixing weight ratio: 70:30) of butyl ether acetate (vapor pressure at 20 ° C. at 1 atm) was added, and after stirring, the mixture was filtered through a 0.2 μm filter to obtain the photosensitive composition of the present invention. It was adjusted.

Example 2
Example 1 except that the solvent to be dissolved is changed to a mixed solvent (mixing weight ratio 60:40) of propylene glycol monomethyl ether acetate and propylene glycol diacetate (vapor pressure is 60 Pa at 1 atm and 20 ° C.) The photosensitive composition of Example 2 was obtained.

Example 3
Except for changing the solvent to be dissolved to a mixed solvent (mixing weight ratio of 40:60) of propylene glycol monomethyl ether acetate and 3-ethoxyethyl propionate (vapor pressure of 93 Pa at 1 atm and 20 ° C.), It carried out like Example 1 and obtained the photosensitive composition of Example 3.

Example 4
The same as in Example 1 except that the solvent to be dissolved is changed to a mixed solvent (mixing weight ratio of 90:10) of propylene glycol monomethyl ether acetate and benzyl alcohol (vapor pressure at 1 atm of 20 ° C. is 13 Pa). The photosensitive composition of Example 4 was obtained.

Example 5
Except that the solvent to be dissolved is changed to a mixed solvent (mixing weight ratio of 95: 5) of propylene glycol monomethyl ether acetate and benzyl alcohol (vapor pressure at 1 atm and 20 ° C. is 13 Pa), the same as in Example 1. The photosensitive composition of Example 5 was obtained.

Example 6
The solvent to be dissolved is a mixture of propylene glycol monomethyl ether acetate, ethylene glycol n-butyl ether acetate (vapor pressure of 20 Pa at 1 atm and 20 ° C) and benzyl alcohol (vapor pressure of 13 Pa at 1 atm and 20 ° C) A photosensitive composition of Example 6 was obtained in the same manner as in Example 1 except that the solvent was changed to a solvent (mixing weight ratio of 80: 15: 5).

Comparative Example 1
A photosensitive composition of Comparative Example 1 was obtained in the same manner as in Example 1 except that the solvent to be dissolved was changed to only propylene glycol monomethyl ether acetate.

Comparative Example 2
Example 1 except that the solvent to be dissolved is changed to a mixed solvent (mixing weight ratio of 40:60) of propylene glycol monomethyl ether acetate and n-butyl acetate (vapor pressure of 1000 Pa at 1 atm and 20 ° C.). The photosensitive composition of Comparative Example 2 was obtained.

Comparative Example 3
Example 1 except that the solvent to be dissolved is changed to a mixed solvent (mixing weight ratio of 40:60) of propylene glycol monomethyl ether acetate and ethyl lactate (1 atm, vapor pressure at 20 ° C. is 279 Pa). It carried out similarly and the photosensitive composition of the comparative example 2 was obtained.

Comparative Example 4
Except that the solvent to be dissolved is changed to a mixed solvent (mixing weight ratio of 60:40) of propylene glycol monomethyl ether acetate and ethylene glycol ethyl ether acetate (vapor pressure at 1 atm of 20 ° C. is 160 Pa). The photosensitive composition of Comparative Example 4 was obtained in the same manner as in Example 1.

Comparative Example 5
Except that the solvent to be dissolved is changed to a mixed solvent (mixing weight ratio of 40:60) of propylene glycol monomethyl ether acetate and ethylene glycol ethyl ether acetate (vapor pressure at 1 atm of 20 ° C. is 160 Pa). In the same manner as in Example 1, a photosensitive composition of Comparative Example 5 was obtained.

Confirmation of coating unevenness and coating uniformity Using a glass substrate with Cr of 120 mm × 200 mm, slit coating was performed with a small slit nozzle (width 100 mm) separated from the glass substrate with Cr by 0.05 mm. The coating speed was set to 100 mm per second, and after coating, it was placed in a vacuum oven and vacuum dried for 40 seconds. The vacuum pressure after 40 seconds was adjusted to about 80 Pa at room temperature. Thereafter, a 2.0 μm resist film was obtained after baking on a hot plate at 100 ° C. for 90 seconds. The obtained resist film was evaluated for coating unevenness by observing the presence or absence of urocomula or stripes under a Na lamp. The coating uniformity was evaluated by measuring the film thickness with a Nanospec M6500 type optical interference film thickness measuring instrument (manufactured by Nanometrics Japan Co., Ltd.). These were evaluated in three stages, with 1 being inferior, 2 being slightly inferior, and 3 being excellent.

Confirmation of unevenness during vacuum drying After application using a slit nozzle in the same manner as the confirmation of unevenness of application and uniformity of application, a pin was placed in a vacuum drying oven and a glass substrate with Cr was placed thereon for drying. After drying in vacuum, the pin mark was dried on a hot plate at 100 ° C. for 90 seconds, and the strength of the pin mark in the vacuum drying oven was evaluated under a Na lamp. Three-point evaluation was performed, with 1 indicating a pin mark conspicuous, 2 indicating a slight pin mark, and 3 indicating no pin mark.

Measurement of pattern shape After applying a small amount onto a 4-inch silicon wafer, it was rotated at 800 rpm for 2 seconds to obtain a pseudo slit film. Then, it put into the vacuum oven and vacuum-dried for 40 seconds. The vacuum pressure after 40 seconds was adjusted to about 80 Pa at room temperature. Thereafter, a 2.0 μm resist film was obtained after baking on a hot plate at 100 ° C. for 90 seconds. This resist film was exposed with a Nikon g + h line stepper (FX-604F) and developed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds. An exposed portion having a 4.0 μm mask size and an exposed portion where the unexposed ratio was 1: 1 were observed with an SEM. FIG. 1 is a schematic cross-sectional view thereof. Depending on its shape, it is 1 with a reverse taper shape close to FIG. 1 (a), a slightly better shape, 2 with a shape close to FIG. 1 (b), and an excellent shape with a tapered shape. A value close to 1 (c) was set to 3, and was evaluated in three stages.

The obtained results were as shown in Table 1.

The cross-sectional schematic diagram of the resist pattern after image development.

Explanation of symbols

1 Substrate 2 Development resist pattern

Claims (4)

A novolac resin, a photosensitizer, and a mixed solvent, wherein the mixed solvent is propylene glycol monomethyl ether acetate, benzyl alcohol, ethylene glycol butyl ether acetate, propylene glycol diacetate, dipropylene glycol dialkyl ether (the carbon number of the alkyl group is 1-5), a co-solvent selected from the group consisting of ethyl 3-ethoxypropionate, butyl lactate, and mixtures thereof and having a vapor pressure at 1 atm of 20 ° C. of 150 Pa or less. The resin composition is applied on the substrate by the slit coating method to form a coating film,
The formed coating film is dried under reduced pressure,
Followed by heat drying to evaporate and remove at least a portion of the solvent,
Imagewise exposure to the desired pattern,
Develop to form a pattern,
A positive pattern forming method comprising heating and curing a pattern after development. The positive pattern forming method according to claim 1, wherein the content of the co-solvent is 5 to 70% by weight based on the weight of the entire mixed solvent. The positive pattern forming method according to claim 1, further comprising a surfactant. The positive pattern forming method according to claim 1, wherein the manufactured pattern is used for manufacturing a liquid crystal display.

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