JP2010175828A - Photosensitive resin composition and method for forming pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosenstive resin composition suitable for forming a resist pattern having a good profile after exposure development, the resist having uniform thickness of coating without causing non-uniform coating even by short-term natural drying without using a method of reduced pressure drying or vacuum drying after slit coating. <P>SOLUTION: The photosensitive resin composition contains a mixture solvent of an alkali-soluble novolac resin, a photosensitive agent containing a quinone diazide group, and propylene glycol monomethylether acetate (A), and a solvent (B) having a boiling point of 145°C or lower and an n-butyl acetate evaporation rate of 50 or more. The composition is applied on a substrate by slit coating, dried without using a method of reduced pressure drying or vacuum drying, then exposed and developed to form a resist pattern. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition suitable for slit coating, a method for forming a resist pattern by a slit coating method, a method for producing a flat panel display (FPD) substrate, and a flat panel display substrate obtained thereby. The present invention relates to a flat panel display using the same.

  The photosensitive resin composition is used for etching resist and protection in the manufacturing process of semiconductor integrated circuit elements, solid-state imaging elements, color filters, and flat panel displays (FPD) such as liquid crystal display elements (LCD) and plasma displays (PDP). It is used for various purposes such as a film, a flattening film for flattening the surface of an element, and an insulating film for maintaining electrical insulation. The photosensitive resin composition is applied on various substrates depending on the purpose of use, and the spin coating method, roll coating method, land coating method, casting coating method, doctor coating method, impregnation coating method, slit coating method are also applied as coating methods. Various methods are known. Various substrates such as silicon, glass, and plastic films are also used as the substrate. For example, glass is frequently used as a substrate in the production of flat panel displays.

  Conventionally, in the manufacture of flat panel displays (FPD) such as liquid crystal display elements and plasma displays, a photosensitive resin composition is used as a photoresist to pattern a driving circuit composed of thin film transistors (TFTs) on a glass substrate. However, spin coating is generally employed as a coating method in the manufacture of small-sized FPDs. In the spin coating method, the photosensitive resin composition is supplied to the center of rotation of the substrate, and the photosensitive resin composition is widely spread by centrifugal force when the substrate is rotated, so that a thin uniform film is formed. The coating film formed by the spin coating method is then heat-dried (prebaked) to remove the solvent from the coating film, and then subjected to an exposure process and a development process with various radiations such as ultraviolet rays, far ultraviolet rays, electron beams, and X-rays. For example, a resist pattern is used. In the spin coating method, a photosensitive resin film having a uniform film thickness can be easily formed. On the other hand, most of the applied photosensitive resin composition is scattered and removed from the outer periphery of the substrate as an excess solution and discarded. Therefore, it has a problem of high cost.

  On the other hand, in recent years, the demand for large-size FPDs has increased, and on the other hand, a plurality of FPDs are created at once on a single large-sized substrate, thereby reducing the manufacturing cost. However, in order to apply a photosensitive resin to a large-sized substrate by a spin coating method, there is a problem that a large apparatus is required and a problem of film thickness uniformity of the applied photosensitive resin composition. Therefore, from the viewpoint of reducing the amount of the photosensitive resin composition to be discarded or preventing the enlargement of the coating apparatus, it is called a slit coating method (slot coating method or spinless coating method) instead of the spin coating method. There is also an attempt to use. In the slit coating method, a substrate is fixed, and a desired amount of the photosensitive resin composition is applied onto the substrate surface from a slit or slot-shaped nozzle that moves on the fixed substrate, or the nozzle is fixed and the substrate is fixed. And a desired amount of the photosensitive resin composition is applied onto the substrate to form a photosensitive resin film. In the slit coating, the solid content of the photosensitive resin composition is usually about 10% in consideration of high-speed coating properties. For example, the coating film thickness is set to 1.5 μm after drying. It is necessary to make it about 10 μm. However, since the coating amount is large and the solvent content is large, there is a problem that the amount of evaporation of the solvent at the time of drying increases, and coating unevenness is easily generated during substrate transportation or in a drying furnace. Therefore, a method has been proposed in which the photosensitive resin composition coated with slits is dried under reduced pressure or vacuum at room temperature (hereinafter, sometimes referred to as “VCD”) before pre-baking to evaporate the solvent in advance. (For example, refer to Patent Document 1).

  There are various conditions for VCD performed after slit coating, but basically a method of suddenly reducing the pressure from about 101 kPa, which is an atmospheric pressure, to about 20 Pa under a room temperature condition in about 30 seconds is often used. 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. In addition, as the size of the substrate increases in recent years, it takes time to install and handle the substrate, so it is necessary to reduce the time required for the VCD in a series of preset processes, and the maintenance burden of the VCD increases. Yes. When the VCD time is shortened, coating unevenness is likely to occur, and even when VCD is performed, only the film surface dries in a short time, so that the vicinity of the resist film surface is difficult to develop and the inside is easily developed. As a result, the pattern shape becomes a shape like a reverse taper (T-top), and there is a problem that defects are likely to occur in a later process (during etching).

  On the other hand, propylene glycol monomethyl ether acetate (PGMEA) is generally used as a solvent used in the photosensitive resin composition. However, since the vapor pressure of PGMEA is about 500 Pa at 20 ° C./1 atmosphere, it is very easy to evaporate at the time of 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, as described above, the vicinity of the surface of the resist film is difficult to be developed, and the inside is easy to be developed. Corner portions remain and etching as designed cannot be performed, which may cause non-uniformity of metal wiring formed using this resist pattern.

  In order to cope with such problems, a photosensitive resin composition suitable for the slit die coater method in which a specific solvent is added, the reduced-pressure drying process time is short, the slit nozzle is difficult to dry, and the coating film surface is good has been developed. (See Patent Document 2). Moreover, the photosensitive resin composition which adjusted the quantity of the photosensitive group which can form the resin pattern uniformly dried by the drying under pressure reduction conditions is also developed (refer patent document 3). Furthermore, a photosensitive resin composition comprising propylene glycol monomethyl ether acetate and a co-solvent having a vapor pressure of 150 Pa or less at 1 atm and 20 ° C. has been proposed (see Patent Document 4).

  For the purpose of forming a color filter or a black matrix using a slit coater, as a solvent, a first solvent that dissolves 50 g or more of a photosensitive resin component per 100 ml, a second solvent having a boiling point of 160 ° C. to 180 ° C., A photosensitive resin composition containing a third solvent having a boiling point of 135 ° C. to 155 ° C. has been proposed (see Patent Document 5). As a method of drying the coating film of this composition, a method of leaving it at room temperature for several hours to several days, or drying with warm air or an infrared electrode for several tens of minutes to several hours is employed. Although VCD is not used, there is a problem that the drying time at room temperature is long. There has also been a demand for a photosensitive resin composition that can be applied to high-speed slit coating without performing a VCD process even in the manufacture of TFT (thin film transistor).

JP 2001-269607 A JP 2007-25645 A WO 2006/107056 JP 2008-158281 A JP 2004-354601 A

  The present invention has been made in order to solve the above-described problems, and without performing vacuum drying or vacuum drying, that is, by performing natural drying for a short time, the coating film is in a uniform state without unevenness. An object of the present invention is to provide a photosensitive resin composition suitable for slit coating that can be dried and has a good resist pattern shape (not a T-top).

  In addition, the present invention provides a pattern forming method for forming a resist pattern having a good shape with uniform drying of a coating film by natural drying in a short time without performing vacuum drying or vacuum drying after slit coating. The purpose is to provide.

  The present invention also provides a flat panel display substrate formed using the photosensitive resin composition, a method for producing the substrate, and a flat panel display including the flat panel display substrate. is there.

  As a result of intensive studies, the present inventors have solved the above problem by using a specific mixed solvent as the solvent in a photosensitive resin composition containing an alkali-soluble novolak resin, a sensitizer containing a quinonediazide group and a solvent. That is, even if the coating film formed by high-speed slit coating is not dried under reduced pressure or vacuum, the coating film can be uniformly dried in a short period of time and a resist pattern having a good shape can be formed. The inventors have found that a photosensitive resin composition can be obtained, and have completed the present invention.

  That is, the present invention relates to a photosensitive resin composition comprising an alkali-soluble novolak resin, a sensitizer containing a quinonediazide group and a solvent, wherein the solvent is propylene glycol monomethyl ether acetate (A) and a boiling point of 145 ° C. or less and n-acetate. The present invention relates to a photosensitive resin composition comprising a mixed solvent with a solvent (B) having a butyl evaporation rate of 50 or more.

  The present invention also relates to an alkali-soluble novolak resin, a photosensitizer containing a quinonediazide group and propylene glycol monomethyl ether acetate (A) and a solvent (B) having a boiling point of 145 ° C. or lower and an n-butyl acetate evaporation rate of 50 or higher. A photosensitive resin composition containing a mixed solvent is slit-coated on a substrate, dried without using a vacuum drying method or a vacuum drying method, and then exposed and developed to form a resist pattern. It relates to a forming method.

  Moreover, this invention relates to the manufacturing method of the board | substrate for flat panel displays (FPD) characterized by including the process of apply | coating the said photosensitive resin composition on a board | substrate by the slit coating method.

  The present invention also relates to a flat panel display (FPD) substrate manufactured by the above-described FPD substrate manufacturing method.

  The present invention also relates to a flat panel display comprising the FPD substrate.

  When the photosensitive resin composition of the present invention is applied by the slit coating method, the resist coating film is dried in a uniform state without unevenness without drying under reduced pressure or vacuum, or by natural drying in a short time. And a pattern such as a resist pattern having a good cross-sectional shape (not a T-top) can be formed.

  In addition, after slit coating using the photosensitive resin composition of the present invention, a reduced-pressure drying or vacuum drying process is not required, so that the cost can be reduced by reducing the number of processes.

  In the present invention, the photosensitive resin composition can be applied at a high speed by applying the photosensitive resin composition using a high-speed slit coating method, and the amount of the photosensitive resin composition applied can be reduced compared to the spin coating method. It is possible to save, and it is possible to form a coating film with a uniform film thickness and uniform coating. Resist patterns and other patterns formed using this coating film have a good cross-sectional shape and are designed. Since the same etching pattern can be formed, an FPD substrate and an FPD with good characteristics can be manufactured at low cost without defective products.

It is a SEM photograph of the resist pattern after development (a) and post-baking (b) obtained by the photosensitive resin composition and method of the present invention. It is a SEM photograph of the resist pattern after development (a) and post-baking (b) obtained by the conventional photosensitive resin composition and method.

  As described above, the photosensitive resin composition of the present invention has an alkali-soluble novolak resin, a photosensitizer containing a quinonediazide group and propylene glycol monomethyl ether acetate (A), a boiling point of 145 ° C. or lower, and an n-butyl acetate evaporation rate of 50 or higher. A mixed solvent with the solvent (B) is contained as an essential component. Hereinafter, it demonstrates concretely from the alkali-soluble novolak resin used with the photosensitive resin composition of this invention.

(Alkali-soluble novolac resin)
The alkali-soluble novolak resin is a polycondensation of at least one kind of phenols and aldehydes such as formaldehyde under acidic conditions using a catalyst such as an inorganic acid, an organic acid, or an organic acid salt of a divalent metal. Can be obtained by a secondary reaction after neutralization and washing with water.

  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 novolak 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 it is lower than this range, it is necessary to apply the composition thickly so that the final resist film has a constant film thickness, the flow inside the coating film tends to occur, and uneven coating 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.

  Moreover, as for the weight average molecular weight (Mw) of alkali-soluble novolak resin, 3,000-16,000 are preferable. The weight average molecular weight in the present invention is a styrene equivalent molecular weight measured by gel permeation chromatography (GPC), but if the weight average molecular weight is less than 3,000, high speed coating at a coating speed of 200 mm / sec or more is performed. In addition, there is a problem that a coating film having a uniform film thickness cannot be formed. On the other hand, when the weight average molecular weight exceeds 16,000, the viscosity of the resin becomes too high, so that it is extracted from the reaction kettle. There is a problem that the weight average molecular weight of the polymer that has started to be significantly different from that of the polymer at the end of the process is so different that stable synthesis cannot be performed.

(Photosensitizer containing a quinonediazide group)
As the photosensitizer containing a quinonediazide group, any of the known photosensitizers conventionally used in quinonediazide-novolak resists can be used. Such a photosensitizer can be 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. The preferred compounds are mentioned. 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'-tetrame Examples include rutriphenylmethane, hydroxytriphenylmethanes such as 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. It is to be noted that, in place of naphthoquinone diazide sulfonic acid chloride, naphthoquinone diazide sulfonic acid alkyl ester or naphthoquinone diazide sulfonic acid alkyl ester may be used to produce a photosensitizer containing the same quinone diazide group as in the case of using naphthoquinone diazide sulfonic acid chloride. it can.

  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 novolak resin. If it is less than this, sufficient sensitivity may not be obtained as a photosensitive tree composition, and if it is more than this, a problem of precipitation of components may occur.

(solvent)
In the photosensitive resin composition of the present invention, propylene glycol monomethyl ether acetate (A) and a solvent (B) having a boiling point of 145 ° C. or lower and an n-butyl acetate evaporation rate of 50 or higher are used as solvents. The solvent (B) having a boiling point of 145 ° C. or lower and an n-butyl acetate evaporation rate of 50 or higher is preferably a solvent having a boiling point of 80 to 130 ° C. and an n-butyl acetate evaporation rate of 70 to 200, more preferably a boiling point. A solvent having an evaporation rate of n-butyl acetate of 70 to 200 at 100 to 130 ° C. In the present invention, preferred as the solvent (B) are isobutanol (boiling point 108 ° C., evaporation rate 74), isopropyl alcohol (boiling point 82 ° C., evaporation rate 190), isobutyl acetate (boiling point 118 ° C., evaporation rate 170), propylene Glycol monomethyl ether (boiling point 120 ° C., evaporation rate 70), n-propylpropionate (boiling point 122.4 ° C., evaporation rate 120), n-butyl acetate (boiling point 126.1 ° C., evaporation rate 100) and the like. More preferred solvents are propylene glycol monomethyl ether (boiling point 120 ° C., evaporation rate 70), n-propylpropionate (boiling point 122.4 ° C., evaporation rate 120), n-butyl acetate (boiling point 126.1 ° C., evaporation). Speed 100).

  The evaporation rate of n-butyl acetate of the solvent is measured according to ASTM D3539, and the evaporation rate coefficient of n-butyl acetate is 100.

  The content of the solvent (B) varies depending on the resist dissolving power of the solvent, but it is preferable to use as much as the solvent dissolves the resist from the viewpoint of increasing the natural drying rate. In general, the ratio of solvent (A) to solvent (B), solvent (A): solvent (B) is preferably 90:10 to 20:80, more preferably 70:30 to 80, based on weight. 30:70. When the content of the solvent (B) is less than 10% by weight, there is a problem that the drying time becomes long and the drying process time becomes long when natural drying is performed. For example, if natural drying is performed for about 10 minutes, a good film without coating unevenness can be obtained even if the solvent content is 10% by weight. However, as described above, the natural drying time is shortened as the solvent content increases. However, it is preferable because a good film can be obtained. However, if the content of the solvent (B) exceeds 80% by weight, depending on the solvent, the solid content of the resist may be precipitated without being dissolved, so the content can be appropriately selected according to the type of solvent used. Necessary.

(Additive)
The photosensitive resin composition of the present invention may further contain an additive as necessary. Examples of the additive include a surfactant added for the purpose of maintaining the uniformity of the photosensitive resin composition and improving the coating property. In particular, when a photosensitive resin composition is applied to a substrate, a scale-like pattern (urocomula) may be generated on the surface. By using a surfactant in the photosensitive resin composition according to the present invention, this phenomenon may occur. Urocomula is suppressed. 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 of this invention can also contain further additives, for example, adhesion promoters, such as a contrast enhancer, an epoxy compound, or a silicon containing compound, as needed. 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 of the present invention is prepared by dissolving each component in a predetermined amount of a solvent. At this time, each component may be prepared by dissolving each component separately in advance in a solvent and mixing each component at a predetermined ratio immediately before use. Usually, the solution of the photosensitive resin composition is subjected to use after being filtered using a 0.2 μm filter or the like. The viscosity is adjusted according to the conditions for applying the photosensitive resin composition, and the kinematic viscosity at 25 ° C. is preferably 2 to 10 cSt, and more preferably 2 to 5 cSt.

  Next, a method for forming a desired resist pattern, for example, using the photosensitive resin composition of the present invention will be described. In the method for forming a miniaturized pattern of the present invention, first, an antireflection film is applied on a base substrate as necessary, and then the photosensitive resin composition of the present invention is applied, and a resist pattern is formed by a photolithography method. The Preferred examples of the base substrate include FPD substrates such as LCD substrates and PDP substrates (glass substrates), but semiconductor substrates (eg, silicon wafers) may also be used. The substrate used as the base substrate may be a bare substrate, and if necessary, a silicon oxide film, a metal film such as aluminum, molybdenum, or chromium on the surface, a metal oxide film such as ITO, or polysilicon. A substrate having a silicon film, or a substrate in which a circuit pattern or a semiconductor element or the like is further formed on the substrate may be used. In the present invention, the photosensitive resin composition is preferably slit-coated by a slit coater. The distance (coating gap) between the nozzle and the substrate at the time of slit coating is arbitrarily selected within a range of about 50 to 200 μm.

  The coated and formed photosensitive resin film is naturally dried at room temperature for about 1 to 10 minutes as necessary, and then pre-baked (for example, baking temperature: about 70 to 140 ° C. for about 1 minute), then exposed and necessary. And post-exposure baking (PEB) (for example, baking temperature: 50 to 140 ° C.), followed by development using an alkaline solution, and post-development baking if necessary (for example, baking temperature: 60 ˜120 ° C.) and a desired photosensitive resin film pattern (for example, a resist pattern). After the photosensitive resin composition is applied to the substrate, a drying step for removing the solvent may be provided if necessary. As the exposure light source, ultraviolet rays such as g-line and i-line, far-ultraviolet rays such as KrF excimer laser and ArF excimer laser, X-rays and electron beams are used according to the characteristics of the photosensitive resin composition used. In addition, as an alkaline solution used as a developing solution, when the photosensitive resin composition is a positive type, the exposed portion of the photosensitive resin film dissolves quickly and the dissolution rate with respect to the unexposed portion is extremely low. Any of these may be used, and specific examples include tetramethylammonium-based aqueous solutions such as tetramethylammonium hydroxide aqueous solution and inorganic alkaline aqueous solutions such as potassium hydroxide and sodium hydroxide. These alkaline aqueous solutions are usually used at a concentration of 15% by weight or less. The developing method may be a method conventionally used for developing a photosensitive resin film, such as an immersion method or a spray method.

  EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples below, but the present invention is not limited to these examples and comparative examples.

Example 1
For 2,100,4 parts of a novolak resin (m-cresol: p-cresol = 60: 40) having a weight average molecular weight of 8,000 in terms of polystyrene, 2,3,4,4′-tetrahydroxybenzophenone and 1, 25 parts by weight of esterified product with 2-naphthoquinonediazide-5-sulfonyl chloride, 1000 ppm of fluorine-based surfactant (nonionic surfactant manufactured by Dainippon Ink & Chemicals, Inc.) is added to the total solid content, and propylene glycol A mixed solvent (mixing weight ratio of 90:10) of monomethyl ether acetate (PGMEA) and n-butyl acetate (nBA) (boiling point: 126.1 ° C., evaporation rate: 100) was added, followed by filtration through a 0.2 μm filter. A photosensitive resin composition 1 having a solvent content of 86% by weight was prepared.

Example 2
Except that the solvent is changed to a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and n-butyl acetate (nBA) (boiling point 126.1 ° C., evaporation rate 100) (mixing weight ratio is 70:30), Examples In the same manner as in No. 1, a photosensitive resin composition 2 was obtained.

Example 3
Except that the solvent is changed to a mixed solvent (mixing weight ratio of 50:50) of propylene glycol monomethyl ether acetate (PGMEA) and n-butyl acetate (nBA) (boiling point 126.1 ° C., evaporation rate 100). In the same manner as in No. 1, a photosensitive resin composition 3 was obtained.

Example 4
Except for changing the solvent to a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and n-propylpropionate (nPP) (boiling point 122.4 ° C., evaporation rate 120) (mixing weight ratio is 90:10), In the same manner as in Example 1, a photosensitive resin composition 4 was obtained.

Example 5
Except for changing the solvent to a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and n-propylpropionate (nPP) (boiling point 122.4 ° C., evaporation rate 120) (mixing weight ratio is 70:30), In the same manner as in Example 1, a photosensitive resin composition 5 was obtained.

Example 6
Except for changing the solvent to a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and n-propylpropionate (nPP) (boiling point 122.4 ° C., evaporation rate 120) (mixing weight ratio 50:50), In the same manner as in Example 1, a photosensitive resin composition 6 was obtained.

Example 7
Example 1 except that the solvent is changed to a mixed solvent (mixing weight ratio 90:10) of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) (boiling point 120 ° C., evaporation rate 70). In the same manner, a photosensitive resin composition 7 was obtained.

Example 8
Example 1 except that the solvent is changed to a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) (boiling point 120 ° C., evaporation rate 70) (mixing weight ratio is 70:30). In the same manner, a photosensitive resin composition 8 was obtained.

Example 9
Example 1 except that the solvent is changed to a mixed solvent (mixing weight ratio 50:50) of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) (boiling point 120 ° C., evaporation rate 70). In the same manner, a photosensitive resin composition 9 was obtained.

Example 10
Example 1 except that the solvent is changed to a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) (boiling point 120 ° C., evaporation rate 70) (mixing weight ratio is 30:70). In the same manner, a photosensitive resin composition 10 was obtained.

Example 11
Example 1 except that the solvent is changed to a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) (boiling point 120 ° C., evaporation rate 70) (mixing weight ratio is 20:80). In the same manner, a photosensitive resin composition 11 was obtained.

Comparative Example 1
A photosensitive resin composition 12 was obtained in the same manner as in Example 1 except that the solvent was changed to only propylene glycol monomethyl ether acetate (PGMEA).

Comparative Example 2
A photosensitive resin composition 13 was obtained in the same manner as in Comparative Example 1 except that the solvent content of the photosensitive resin composition was changed to 85% by weight.

Comparative Example 3
A photosensitive resin composition 14 was obtained in the same manner as in Comparative Example 1 except that the solvent content of the photosensitive resin composition was changed to 84% by weight.

Comparative Example 4
A photosensitive resin composition 15 was obtained in the same manner as in Comparative Example 1 except that the solvent content of the photosensitive resin composition was changed to 83% by weight.

  The compositions of the photosensitive resin compositions 1 to 15 in Examples 1 to 11 and Comparative Examples 1 to 4 are summarized in Table 1 below.

[Photosensitive resin composition application tests 1 to 30]
About the photosensitive resin compositions 1-15 obtained in Examples 1-11 and Comparative Examples 1-4, application | coating and drying were performed on the following conditions, and the coating unevenness and the coating uniformity were evaluated.

Coating and Drying Conditions Using a glass substrate with Cr of 730 mm × 920 mm, slit coating was performed with a small slit nozzle (width 700 mm) separated from the glass substrate with Cr by 140 μm. The coating speed was set to 100 mm per second, and after coating, natural drying was performed at 23 ° C. for the time shown in Table 2, and after baking on a hot plate at 100 ° C. for 150 seconds, a 1.5 μm resist film was obtained.

<Evaluation of coating unevenness>
The obtained resist film was visually observed under a Na lamp, and coating unevenness was evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
○: Application unevenness is not confirmed Δ: Application unevenness is slightly confirmed ×: Application unevenness is clearly confirmed

<Evaluation of coating uniformity>
The coating uniformity was evaluated according to the following evaluation criteria by measuring the film thickness with a Nanospec M6500 type optical interference film thickness measuring device (manufactured by Nanometrics Japan Co., Ltd.).
〔Evaluation criteria〕
○: Film thickness uniformity is good △: Film thickness uniformity is slightly inferior ×: Film thickness uniformity is inferior

[Photosensitive resin composition application test 31] (Drying under vacuum drying conditions)
Using the photosensitive resin composition 12 obtained in Comparative Example 1, vacuum drying was performed instead of natural drying, and coating unevenness and coating uniformity were evaluated.
That is, after applying the photosensitive resin composition 12 using a slit nozzle as in the photosensitive resin composition application tests 1 to 30, a pin was placed in a vacuum drying oven and a Cr-attached glass substrate was placed thereon and dried. It was. After vacuum drying, it was dried on a hot plate at 100 ° C. for 90 seconds, and evaluated based on the above evaluation criteria for coating unevenness and coating uniformity. The results are shown in Table 2.

  From Table 2, the photosensitive resin composition of the present invention is a resist film having a uniform coating thickness with no coating unevenness regardless of whether the natural drying time before pre-baking is short or the drying time is long or short. It can be seen that it can be formed.

[Pattern shape confirmation test]
After applying a small amount of each of photosensitive resin compositions 5, 8, and 10 (samples 5, 8, and 10) on a 4-inch silicon wafer, a coating film similar to slit coating was obtained (800 seconds for 2 seconds) Rotation) A resist coating film made of each photosensitive resin composition was obtained. Then, natural drying was performed for 3 minutes at 23 degreeC. Thereafter, a resist film having a thickness of 1.5 μm 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. Thereafter, post-baking was performed on a hot plate at 130 ° C. for 2 minutes. An exposed portion having a 4.0 μm mask size and an exposed portion having an unexposed ratio of 1: 1 were observed by SEM after development and post-baking. The results are shown in FIG. 1A shows a resist shape after development, and FIG. 1B shows a resist shape after post-baking. In any sample, the resist shape after development was trapezoidal, and the post-baking shape was a kamaboko shape that was a desired shape.

  On the other hand, a resist pattern was formed in the same manner as described above except that the photosensitive resin composition 12 was used as the photosensitive resin composition and vacuum drying was performed at 100 Pa / 40 seconds, and the shape after development and post-baking Was observed with SEM. The results are shown in FIG. As in FIG. 1, (a) shows the resist shape after development, and (b) shows the resist shape after post-baking. As shown in FIG. 2, when vacuum drying is performed using a photosensitive resin composition having a conventional composition, the resist shape becomes T-top, and a desired cross-sectional shape (kamaboko shape) is obtained after post-baking. could not.

  From the pattern shape confirmation test, it is understood that a pattern having a desired cross-sectional shape can be obtained by forming a pattern using the photosensitive resin composition of the present invention.

  The photosensitive resin composition of the present invention can be uniformly applied on a substrate at high speed without application unevenness by a slit coating method. The resulting coating film is used for etching resist and protection in the manufacturing process of semiconductor integrated circuit elements, solid-state image sensors, color filters, and flat panel displays (FPD) such as liquid crystal display elements (LCD) and plasma displays (PDP). A substrate having a fine circuit pattern such as an FPD substrate using a formed resist pattern can be used as a film, a planarizing film for planarizing an element surface, an insulating film for maintaining electrical insulation, etc. Can be formed.

Claims (7)

In a photosensitive resin composition comprising an alkali-soluble novolak resin, a sensitizer containing a quinonediazide group and a solvent,
A photosensitive resin composition, wherein the solvent comprises a mixed solvent of propylene glycol monomethyl ether acetate (A) and a solvent (B) having a boiling point of 145 ° C. or lower and an n-butyl acetate evaporation rate of 50 or higher.   The solvent (B) having a boiling point of 145 ° C. or lower and an n-butyl acetate evaporation rate of 50 or higher is at least one selected from propylene glycol monomethyl ether, n-propyl propionate, and n-butyl acetate. The photosensitive resin composition of Claim 1 characterized by the above-mentioned.   Photosensitivity including alkali-soluble novolak resin, photosensitizer containing quinonediazide group, and mixed solvent of propylene glycol monomethyl ether acetate (A) and solvent (B) having a boiling point of 145 ° C. or lower and an n-butyl acetate evaporation rate of 50 or higher. A pattern forming method comprising: slit-coating a resin composition on a substrate; drying without using a method using reduced pressure drying or vacuum drying; and then exposing and developing to form a resist pattern.   The solvent (B) having a boiling point of 145 ° C. or lower and an n-butyl acetate evaporation rate of 50 or higher is at least one selected from propylene glycol monomethyl ether, n-propyl propionate, and n-butyl acetate. The method for forming a pattern according to claim 3.   A method for producing a flat panel display substrate, comprising a step of applying the photosensitive resin composition according to claim 1 or 2 onto a substrate by a slit coating method.   A flat panel display substrate manufactured by the manufacturing method according to claim 5.   A flat panel display comprising the flat panel display substrate according to claim 6.