TW200421020A - Positive photoresist composition and method for forming resist pattern - Google Patents

Abstract

A positive photoresist composition is provided which can prevent deformation of a resist pattern in high temperature postbaking steps, and decrease degassing in high temperature heating. This positive photoresist composition includes (A) alkaline soluble novolak resin having polystyrene reduced weight average molecular weight of not less than 20000, and containing not more than 4% of binuclear compounds, (B) a compound containing a phenolic hydroxyl group with Mw of no more than 1000, (C) naphthoquinonediazido group containing compound, and (D) an organic solvent.

Description

200421020 Π) 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a method for forming a positive type photoresist composition and a photoresist pattern. [Prior art] So far in the field of manufacturing a liquid crystal display element using a glass substrate, Because it is cheaper and can form photoresist patterns with excellent sensitivity, resolution, and shape, phenolic lacquer resins are mostly used as alkali-soluble resins, and compounds containing naphthoquinonediazide groups are used for photosensitivity. A positive photoresist composition having a composition as a photoresist material has been reported (see Patent Documents 1 and 2 below). f Patent Document 1] JP 2000- 1 3 1 835 [Patent Document 2] JP 2001-75272 Conventionally, a liquid crystal panel for a liquid crystal display element is configured by forming amorphous silicon on a glass substrate, for example Thin-film transistor panels, but in recent years, polycrystalline silicon has tended to replace amorphous silicon. In particular, low-temperature polycrystalline silicon formed in a low-temperature step below 600 ° C has lower resistance and higher mobility than amorphous silicon, and is therefore attracting attention as a second-generation high-performance liquid crystal substrate. However, after manufacturing a TFT composed of low-temperature polycrystalline silicon, after forming a polycrystalline silicon film on a glass substrate in a low-temperature step, insert the low-temperature polycrystalline film? In the so-called "implantation step," and B and the like, it is necessary to enter a non-suspended impurity-5 ^ (2) (2) 200421020 This implantation step is a low temperature to form a low-temperature polycrystalline silicon film on a glass substrate. On the polycrystalline silicon glass substrate, the photoresist pattern is formed under high vacuum conditions. It has been reported that if the photoresist pattern on the substrate is heated by the heating effect of the impurity, the photoresist pattern A certain component in the mold vaporizes and has the problem of reducing the degree of vacuum in the processing chamber. Therefore, the means to solve this problem is known before the implantation step, and adding a so-called "post-baking" heat treatment step is an effective means. Thereafter, the baking is performed at a temperature close to the heating temperature at the time of implantation, for example, at a temperature of 200 ° C or higher, and the photoresist pattern is heated in advance to reduce the photoresist pattern from the photoresist pattern during the implantation step. The amount of degassing is for this purpose. [Summary of the Invention] [Problems to be Solved by the Invention] However, the conventional photoresist composition for manufacturing a liquid crystal display element has a problem that the photoresist pattern flows during post-baking and the shape change easily occurs. In addition, during the post-baking process, the amount of degassing from the photoresist pattern causes the micropores and cracks in the processing chamber to be polluted and the photoresist pattern to become porous. problem. In view of the foregoing, the present invention provides a photoresist composition capable of preventing deformation of the photoresist pattern in a post-baking step at high temperature and reducing the amount of outgassing during high temperature heating, and a method for forming a photoresist pattern using the composition. For its purpose. [Means to Solve the Problem] The present inventors and others have worked hard to solve the above-mentioned problems. As a result, -6-(3) (3) 200421020 has been converted to a polystyrene with a mass average molecular weight as high as 20,000. Above, and a phenolic lacquer resin having a dinuclear content of as little as 4% or less as an alkaline soluble resin, the heat resistance of the photoresist pattern can be improved, and the amount of outgassing can be reduced, and the present invention has been completed. That is, the positive-type photoresist composition of the present invention is characterized by containing (A) a compound having a mass average molecular weight (Mw) of 20,000 or more and a dinuclear content of 4% or less as converted to polystyrene by gel permeation chromatography. The basic soluble phenolic lacquer resin is composed of (B) a compound containing a phenolic hydroxyl group having a molecular weight of not more than 20000, (C) a compound containing a naphthoquinonediazide group, and (D) an organic solvent. The positive type photoresist composition of the present invention can be suitably used as a photoresist pattern material for manufacturing liquid crystal display elements. Therefore, the present invention also provides a liquid crystal display device manufactured using the aforementioned positive-type photoresist composition. The present invention also provides a step of applying the positive photoresist composition of the present invention on a substrate, post-baking and forming a photoresist film, and a step of selectively exposing the photoresist film. The photoresist film after selective exposure is developed using an alkaline aqueous solution to develop a photoresist pattern in the step of forming a photoresist pattern on the aforementioned substrate. The substrate is a low temperature having a low temperature polycrystalline silicon film on a glass substrate. A polycrystalline silicon glass substrate is a method for forming a photoresist pattern. In addition, the photoresist pattern after the development process can be post-baked at a high temperature of 200 t or more. The "constituent unit" as used herein means a unit unit that constitutes a polymer (resin). -7-(4) (4) 200421020 In addition, the dinuclear body in the present invention is a condensate molecule having two phenolic nuclei, and the content of the dinuclear body is based on gel permeation chromatography (also briefly described in this specification as GPC) at the detection wavelength of 280 nm. In the present specification, the content of dinuclear bodies is specifically the tritium measured using the following GPC system. Device name: SYSTEM 1 1 (product name, manufactured by Showa Denko) Precolumn: KF-G (product name, manufactured by Shodex) Column: KF-8 02 (product name, manufactured by Shodex) Detector: UV41 (product name, (Shode X Co., Ltd.), measured at 280 nm. Solvents, etc .: Tetrahydrofuran was passed at a flow rate of 1.0 ml / min and measured at 35 ° C. [Embodiments of the invention] Hereinafter, the present invention will be described in detail. [(A) component] The alkaline soluble phenolic lacquer resin (A) used in the present invention can be arbitrarily selected and used from the positive photoresist composition usually used as a film-forming substance, and the entire (A) component is prepared by The mass average molecular weight (hereinafter referred to as "M w") converted into polystyrene based on GPC is not less than 20000, and the dinuclear content may be 4% or less. By making the Mw of the component (A) be more than 20,000, even if the high temperature heat treatment of 200 t or more, preferably 220 to 250 ° C is applied in post-baking, etc., it can be achieved that the photoresist pattern does not occur. Type of flow phenomenon degree of heat resistance. The larger the Mw is, the higher heat resistance can be achieved. However, if the Mw is too large, the coating property of the base (5) (5) 200421020 tends to deteriorate. Therefore, the Mw of the (A) component The upper limit 値 is preferably around 50,000. (A) A more preferable range of the Mw of the component is about 21,000 to 35,000. In addition, by reducing the content of the dinuclear bodies in the component (A) to 4% or less, the post-baking temperature of 200 ° C or higher, preferably 220 to 250 ° C, is used to reduce the amount of degassing during high-temperature heat treatment. And it can prevent the shrinkage of photoresist pattern, micropores, cracks, etc., and can suppress the pollution in the processing chamber caused by the degassing of photoresist pattern. (A) The smaller the content of the dinuclear body in the component, the lower the amount of degassing during heating, but the smaller the content of the dinuclear body, the greater the manufacturing cost. Therefore, the lower limit of the content of the dinuclear body in the (A) component is About 0.1% is preferred. The more preferable range of the content of the dinuclear body in the component (A) is about 1.0 to 3.0%. Specific examples of the alkali-soluble phenolic lacquer resin (A) include phenolic lacquer resins obtained by reacting the phenols exemplified below with the aldehydes exemplified below under an acid catalyst. Examples of the phenols include phenol; cresols such as m-cresol, p-cresol, ortho-cresol; 2,3-xylenol, 2,5-xylenol, and 3,5-xylenol Xylenols such as phenol and 3,4-xylenol; m-ethylphenol, p-ethylphenol, o-ethylphenol, 2,3,5-trimethylphenol '2,3,5 Triethylphenol, 4-thirdbutylphenol, 3-thirdbutylphenol, 2-thirdbutylphenol, 2-thirdbutyl-4-methylphenol, 2-thirdbutyl- Alkyl phenols such as 5-methylphenol; p-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, m-ethoxyphenol, p-propoxyphenol, m-propyl Alkoxyphenols such as oxyphenol; o-isopropenylphenol, p-isopropenylphenol, 2-methyl-9- (6) (6) 200421020 4-isopropenylphenol, 2-ethyl Isopropenyl phenols such as 4-isopropenyl phenol; aryl phenols such as phenyl phenol; 4,4, · dihydroxybiphenyl, difluorene A, resorcinol, hydroquinone, pyrofluorene Polyhydroxyphenols such as phenol. They can be used alone or in combination of two or more. Among these phenols, m-cresol, p-cresol, and 2,3,5-H methylphenol are particularly preferred. Examples of the aldehydes include formaldehyde, p-formaldehyde, tri-Dfane, acetaldehyde, propanal, butyraldehyde, trimethylacetaldehyde, acrolein, butenal, cyclohexanal, furfural, furyl acrolein, and benzaldehyde , P-phthalaldehyde, phenylacetaldehyde, α-phenylpropanal, / 5-phenylpropanal, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-methylbenzaldehyde, M-methylbenzaldehyde, p-methylbenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, cinnamaldehyde, etc. They can be used alone or in combination of two or more. Among these aldehydes, formaldehyde is preferred in terms of ease of acquisition, and hydroxybenzaldehyde and formaldehyde are preferably used in combination in order to improve heat resistance. Examples of the acidic catalyst include hydrochloric acid, sulfuric acid, formic acid, oxalic acid, and p-toluenesulfonic acid. (A) The Mw and dinuclear content of the components are obtained by synthesizing the condensation reaction of phenols and aldehydes through the usual synthetic reaction of phenolic lacquer resin, and then the low molecular region can be cut out according to known classification and other operations. Adjustment. The treatment such as classification is, for example, the phenolic lacquer resin obtained by the condensation reaction in a good solvent, such as alcohols such as methanol, ethanol, ketones such as acetone, methyl ethyl ketone, and ethylene glycol monoethyl ether acetate, tetrahydrofuran. It can be dissolved by dissolving in water, followed by pouring into water to precipitate it. In addition, in the case of the synthesis reaction (condensation reaction) of phenolic lacquer resin, it is possible to reduce the content of dinuclear bodies by steam distillation (-10-2000-1 3 1 8 5) Bulletin). Further, in the present invention, the component (A) may be composed of one type of phenolic lacquer resin, or may be composed of two or more types of phenolic lacquer resin. When composed of two or more types of phenolic lacquer resins, it may also contain phenolic lacquer resins with a Mw of 20,000 or more and a dinuclear content of 4% or less, and (A) the entire component is Mw 20000 or more. The nucleus content may be less than 4%. Therefore, by appropriately mixing and using two or more phenolic resins having different Mw and dinuclear content, the Mw and dinuclear content of the component (A) can also be adjusted. [(A 1) component] In the present invention, it is preferable that the alkaline soluble phenol resin (A) contains a phenolic varnish resin (A1) having an M w of 3 00 00 to 40000. If the Mw of this (Α1) component is less than 30,000, it is difficult to prepare a photoresist composition with excellent heat resistance. If it exceeds 40,000, it is difficult to peel the photoresist pattern from the substrate in the photoresist pattern peeling step. The tendency of Mw is not good. The preferred range of Mw of (A1) is 32000 ~ 38000. The (A 1) component preferably contains a constituent unit derived from m-cresol and a constituent unit derived from 2,3,5-trimethylphenol. Although the constituent unit derived from m-cresol contributes to the improvement of sensitivity ', the film tends to be thinner in resolution. On the other hand, the constituent units derived from trimethylphenol of 2,3,5 have a tendency to reduce sensitivity. Although 2,3,5-trimethylphenol is expensive, it contributes to resolution. improve. M_ -11-(8) (8) 200421020 Both cresol and 2,3,5-trimethylphenol are highly reactive, easy to quantify, and difficult to form dinuclear bodies. In particular, the reactivity of m-cresol is high. Therefore, the phenolic lacquer resin obtained by the reaction of m-cresol and 2,3,5-trimethylphenol has a Mw of (1) component as high as 30,000 to 40,000, and the sensitivity and resolution of the photoresist composition can be suppressed. It is preferred because it deteriorates and increases heat resistance. (A1) The content of the dinuclear body in the component is preferably 4.0% or less. The smaller the content of the dinuclear body in the component (A1) is better, but the smaller the content of the dinuclear body, the greater the manufacturing cost, so the lower limit is 値It is preferably about 0.1%. The more preferable range of the content of the dinuclear body in the component (A1) is about 1.0 to 3.0%. (A 1) Among all the constituent units derived from the phenols constituting the component, the constituent unit derived from m-cresol contains 80 mol% or more and is derived from 2,3,5-trimethylphenol The derived constituent unit preferably contains 5 mol% or more. Especially the (A 1) component is a two-component phenolic resin based on m-cresol-derived unit and 2,3,5-trimethylphenol-derived unit. The heat resistance and the photoresist pattern peelability in the photoresist pattern peeling step are good. In this case, the molar ratio of the constituent unit derived from m-toluol / the constituent unit derived from 2,3,5-trimethylphenol is preferably within a range of 80/20 to 95/5. When the (A1) component is used, a preferable content ratio of the (A1) component in the (A) component is 50% by mass or more, and more preferably 70% by mass or more. It may also be 100% by mass. If the (A 1) component is less than the above range, it will be difficult to form a photoresist pattern having excellent heat resistance. The synthetic method of phenolic lacquer resin (A 1) can use the general phenolic resin-12- (9) (9) 200421020 lacquer resin synthesis reaction, using at least m-cresol and 2,3,5_trimethyl Condensates of phenols and phenols are synthesized in accordance with a conventional method with formaldehyde, and thereafter, the contents of Mw and dinuclear bodies can be adjusted to a desired range through operations such as classification. [(A2) component] The component (A) is composed of a mixture of two or more phenolic lacquer resins, and a phenolic lacquer resin (A2) containing Mw of 3000 to 7000 is preferable. Among the components of (A2) If the Mw is less than 3000, it is difficult to prepare a photoresist composition having excellent heat resistance, and if it exceeds 7,000, the sensitivity of the photoresist tends to decrease, which is not preferable. (A2) The component preferably contains a constituent unit derived from m-cresol and a constituent unit derived from p-cresol. As mentioned above, although the constituent unit derived from m-cresol contributes to the improvement of sensitivity, it tends to be thinner in the resolution. On the other hand, although the constitutional unit derived from p-cresol tends to reduce sensitivity, it contributes to improvement in resolution. In addition, although p-toluene is inexpensive, its reactivity is low when compared with m-cresol and 2,3,5-trimethylphenol. Therefore, by including the (a 2) component in the (A) component, the sensitivity, resolution, and residual film ratio of the photoresist composition can be effectively improved. The content of the dinuclear bodies in the component (A2) is preferably 10% or less. (A2) The smaller the content of the dinuclear body in the component, the better, but if the content of the dinuclear body is too small, the manufacturing cost will increase, so the lower limit 値 is preferably about 1%. (A2) The more preferable range of the content of the nuclear body in the component-13-(10) (10) 200421020 is about 3.0 to 7.0%. (Α2) Among all the constituent units derived from the phenols constituting the component, the constituent unit derived from m-cresol is 30 mol% or more, and the constituent unit derived from p-cresol is contained Above 60 mol% is preferred. Especially the (A2) component is a two-component phenolic lacquer resin composed of a constituent unit derived from m-cresol and a constituent unit derived from p-cresol, which can form a photoresist pattern with excellent residual film rate. The words are better. In this case, the molar ratio of the constituent units derived from m-cresol / the constituent units derived from p-cresol is preferably 30/70 to 40/60. By including the (A2) component in the (A) component, good sensitivity and resolution can be easily achieved. When the (A2) component is used, the preferred content ratio of the (A2) component in the (A) component is 5 to 70% by mass, and more preferably 10 to 60% by mass. If the (A2) component is less than the above range, the effect of improving sensitivity and residual film rate is lacking, and if it is too much, the heat resistance tends to deteriorate. Synthetic method of phenolic lacquer resin (A2) can use the general synthetic reaction of phenolic lacquer resin, using phenols containing at least m-cresol and p-cresol, and formaldehyde with formaldehyde and synthesize condensate according to a common method, and thereafter, Through the operations such as classification, the Mw and dinuclear content can be adjusted to the desired range. In the present invention, the component (A) contains both the components (A1) and (A2) described above, and the whole is prepared so that Mw is 20,000 or more, and the content of the dinuclear body is preferably 4% or less. After mixing the two, If necessary, a grading treatment can be applied, and the Mw and dinuclear content can be adjusted. At this time, the content ratio of the (A1) component to the (A2) component is preferably within a range of (A1) / (A2) = 1/1 to 5/1 (mass ratio), and 1.5 / 1 to 3/1 ( Quality ratio) is better. -14- (11) (11) 200421020 If necessary, the component (A) may contain phenolic lacquer resin other than (A) and (A2). The total content of (A1) and (A2) in the (A) component is preferably 50% by mass or more, more preferably 90% by mass, and 100% by mass. [(B) Component] The positive-type photoresist composition of the present invention can obtain the effect of improving sensitivity by containing a compound (B) 'containing a phenolic hydroxyl group having a molecular weight of 1,000 or less. In particular, in the field of manufacturing liquid crystal display elements, 'increasing the throughput is a very large problem, and since the photoresist consumes a large amount, it is desirable that the photoresist composition is highly sensitive and inexpensive. If this (B) component is used, It is preferable to achieve higher sensitivity at a lower cost. In addition, if the component (B) is contained, a surface insolubilization layer is strongly formed in the photoresist pattern. Therefore, the film reduction of the photoresist film in the unexposed portion during development is small, and the occurrence of development time differences can be suppressed. The development is uneven, so it is better. If the molecular weight of the component (B) exceeds 1,000, the effect of improving the sensitivity will not be obtained, and it is not good. As the component (B), a compound having a phenolic hydroxyl group having a molecular weight of 1 000 or less, which is used in a conventional photoresist composition used for the manufacture of a liquid crystal display element, may be appropriately used. A hydroxy compound is more effective because it improves sensitivity and has good heat resistance. -15- (12) (12) 200421020

[In the formula, R1 to R8 are each independently a hydrogen atom, a halogen atom, an alkyl group having a carbon number of Γ ~ 6, an alkoxy group having a carbon number of 1 to 6, or a cycloalkyl group having a carbon number of 3 to 6; R9 to R1 1 each independently represent a hydrogen atom or an alkyl group having i to 6 carbon atoms; 0 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a residue represented by the following chemical formula (IV)

(In the formula, 'R and each independently represent a hydrogen atom, a halogen atom', an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms; 0 Are integers from 1 to 3); a, b are integers from 1 to 3; d is an integer from 0 to 3, or Q is a carbon chain that is bound to R9 and the carbon atoms between Q9 and R9 form a carbon chain 3 to 6 cycloalkyl groups; η is an integer representing 0 to 3] Any one of them may be used, or two or more of them may be used. Among compounds containing a phenolic hydroxyl group, the compound represented by the following formula (I): (1- [1- (4-hydroxyphenyl) isopropyl] _xin [1,1_bis (4-hydroxyphenyl) Ethyl] benzene) and bis (2,3,5-trimethyl-4-hydroxyphenyl) -2-hydroxyphenylmethane are particularly excellent because they are highly sensitive and have a high residual film ratio. In particular, it is represented by the above formula (I): -16-(13) (13)

The compound of OH 200421020 is preferable in terms of high sensitivity.

OH

C——CHs (I) (B) The blending amount of the component is relative to the (A) component's test value. Soluble 14% acetaldehyde lacquer resin 100 parts by mass, 1 ~ 25 parts by mass, preferably 5 ~ 2 () The range of stomach weight% is preferable. If the (6) component in the photoresist composition contains 4 and / or, the improvement effect of high sensitivity and high residual film rate cannot be sufficiently obtained. ^ # Too much, residues are likely to occur on the substrate surface after development. And the raw stomach φ becomes high, so it is not good. [(C) Component] The compound (C) containing a naphthoquinonediazide group in the present invention is a photosensitive component. As the (C) component, for example, a conventional photoresist composition for liquid crystal display element manufacturing can be used as the photosensitive component. For example, the component (C) is preferably an esterification reaction product (C1) of a phenolic hydroxyl group-containing compound and a 1,2-naphthoquinonediazidesulfonic acid compound represented by the following formula (II) and / or An esterification reaction product of a phenolic hydroxyl group-containing compound represented by the following formula (III) and a 1,2-naphthoquinonediazidesulfonic acid compound

-17- (14) 200421020

(C 2). The above 1,2-naphthyldiazidesulfonic acid compound is preferably a quinonediazide-5-sulfofluorene compound.

[Wherein 'R] to R8 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms, respectively. ; R9 ~ R11 each independently represent a hydrogen atom or an alkyl group having 6 to 6 carbon atoms; Q is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a residue represented by the following chemical formula (iv)

(IV) (In the formula, R ”and R13 each independently represent a hydrogen atom, a halogen atom, and a carbon number] to 6 alkyl groups, 1 to 6 carbon alkoxy groups, or 3 to 6 carbon atoms Cycloalkyl; c is an integer representing [~ 3), or a cycloalkyl group which is combined with R9 and carbon atoms between R9 and Q and R9 to form a carbon chain of 3 to 6; a and b represent] An integer of 3; d is an integer of 0 to 3 as shown in Table-18- (15) (15) 200421020; η is an integer of 0 to 3] (C1) The average esterification rate of the component is 50 to 70%, preferably It is 55 to 65%. If it is less than 50%, film thinning tends to occur after development, and it is not good in terms of the residual film rate. If it exceeds 70%, it tends to reduce storage stability. (C2) The average esterification rate of the component (C2) is 40 ~ 60%, preferably 45 ~ 55%, less than 40 ° /. Then the film thinning is easy to occur after development, and the residual film rate is easy. If it exceeds 60%, the sensitivity tends to deteriorate significantly. (C2) The component is a compound containing a phenolic hydroxyl group and a 1,2-naphthoquinonediazidesulfonic acid compound represented by the following formula (V). Esterification reaction product (C3), especially due to the formation of photoresist patterns with high resolution Excellent strength, it is preferred

In addition, the component (C) may use other quinonediazide esters in addition to the above-mentioned photosensitive component, and the amount of the component (C) is preferably 30% by mass or less, and particularly preferably 25% by mass or less. . The compounding amount of the component (C) in the photoresist composition of the present invention is relative to the total of the alkali-soluble phenolic lacquer resin (A) and the compound containing a phenolic hydroxyl group. 19- (16) (16) 200421020 (B) The amount is preferably 100 parts by mass, and preferably within a range of 15 to 40 parts by mass, preferably 20 to 30 parts by mass. If the content of the component (C) is less than the above range, the decrease in transferability becomes large, and a photoresist pattern of a desired shape cannot be formed. On the other hand, if it is more than the above range, sensitivity and resolution are deteriorated, and residues are liable to occur after development processing. The (C) component is particularly preferably (C1), which is a very inexpensive photoresist composition capable of modulating a high sensitivity and having excellent heat resistance. Further, the (C) component can be selected based on the exposure wavelength used in the development step. For example, in the step of performing selective exposure, (C1) is appropriately used when performing ghi-ray (g-ray, h-ray, and i-ray) exposure, and (i.e., (C2)) may be used when i-ray exposure is performed, or (C1) and (C2) are preferred. Particularly when i-ray exposure is performed, in the case where (C1) and (C2) are used, their blending ratio is preferably 80 parts by mass or less with respect to (C2) 50 parts by mass. If the blending amount of (C1) is too large, the resolution and sensitivity may decrease. [(D) Component] The composition of the present invention is preferably a solution type in which the components (A) to (C) and various additional components are dissolved in an organic solvent (D). The organic solvent used in the present invention is propylene glycol monomethyl ether acetate (PGMEA), which is excellent in coating properties and excellent in film thickness uniformity of a photoresist film on a large glass substrate. PG Μ EA is best used in a separate solvent, but -20- (17) (17) 200421020 can be blended with a solvent other than PGMEA. Examples include ethyl lactate, r-butyrolactone, and propylene glycol monobutylene. Acid etc. When using ethyl lactate, it is desired that the blending mass ratio is 0.1 to 10 times the amount relative to PGMEA, preferably! A range of ~ 5 times the amount. In addition, when 7-butyrolactone is used, the blending mass ratio is preferably from 0.001 to 1 times the amount of PGMEA, preferably from 0.05 to 0.5 times the amount. Especially in the field of manufacturing liquid crystal display elements, it is usually necessary to form a photoresist film having a thickness of 0.5 to 2.5 μm, especially 1.0 to 2.0 μm on a glass substrate. Therefore, using these organic solvents, the photoresist composition The total amount of the components (A) to (C) above is 30% by mass or less with respect to the total mass of the composition, and preferably 15 to 30% by mass. / 〇, more preferably adjusted to 20 to 28% by mass, and more preferable in terms of achieving good coatability. [Other components] In the composition of the present invention, various additives such as a surfactant and a storage stabilizer can be used as long as the object of the present invention is not impaired. _, Which may contain a suitable ultraviolet absorber for preventing halo, such as 2,2,4 ^ _ '彳, 4-tetrahydroxybenzophenone, 4-dimethylamino-2', 4 '· dihydroxybenzophenone 5.Amine-3 methyl-phenylphenyl-4- (4-hydroxyphenylazo) pyrazole'4-dimethylamino H-azo azobenzene, 4-diethylamino-4 ' -Ethoxy azobenzene, 4-diethylamine, azobenzene, curcumin, etc., and surfactants to prevent streaks, such as Fuloride FC-430, FC431 (trade name, made by Sumitomo 3M (Stock) ), Efmop EF122A, EF122B, EF122C, EF126 (trade name, manufactured by Tokem Products) and other fluorine-based interfacial activity, -21-(18) (18) 200421020

Fluoro-silicone surfactants such as Megafac R-60 (trade name, manufactured by Dainippon Ink Chemical Industry Co., Ltd.) and the like. The photoresist composition containing such components (A) to (D) has good heat resistance, and also suppresses a small amount of dinuclear bodies, so that the amount of outgassing during high-temperature heating is small. Therefore, it is suitable for forming a photoresist pattern used in a manufacturing step of a liquid crystal display element with high temperature post-baking, and it is also suitable for manufacturing an LCD using a low temperature polycrystalline silicon glass substrate. An embodiment of a method for forming a photoresist pattern of the present invention will be described. First, a positive photoresist composition of the present invention prepared in a solution form is applied on a substrate using a suitable coating means such as a spin coater, and a coating film is formed. The substrate used at this time was a low-temperature polycrystalline silicon glass substrate used to form a low-temperature polycrystalline silicon film on a glass substrate. On the low-temperature polycrystalline silicon glass substrate, a layer other than the low-temperature polycrystalline silicon film may be formed as required. Next, the substrate on which the coating film is formed is heated and dried (pre-baked) at about 100 to 140 t to form a photoresist film. Next, for the photoresist film, selective exposure is performed through a desired mask pattern. Ghi rays or i rays can be suitably used for the wavelength of the exposure, and various appropriate light sources can be used. Next, for the photoresist coating after selective exposure, a developing solution made of an alkaline aqueous solution, such as a 1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution, is used for development processing. The method for bringing the photoresist film into contact with the developing solution can be, for example, a method in which a liquid is filled from one end to the other end of the substrate, and a nozzle for developing liquid dripping provided near the center of the substrate is used to make the surface of the substrate The whole method of imaging solution-22- (19) (19) 200421020. Thereafter, it was left to stand for about 50 to 60 seconds and developed, and a photoresist pattern was formed on the substrate. Thereafter, the developing solution remaining on the surface of the photoresist pattern is washed away with a washing solution such as pure water, and a washing step is performed. The substrate is a low-temperature polycrystalline silicon glass substrate. In the case where the substrate is provided for the implantation step, the photoresist pattern after the development process is subjected to a high-temperature post-baking at 200 ° C or higher, and then the implantation step is performed. The heat treatment temperature during the high-temperature post-baking is preferably 220 ° C or higher, and may be, for example, 220-2050 ° C. According to the method for forming such a photoresist pattern, the photoresist composition has good heat resistance and the amount of outgassing can be suppressed and reduced. Therefore, even if a high-temperature heat treatment is applied, the flow of the photoresist pattern can be prevented. Pollution caused by degassing in the processing room; micro-holes, cracks, shrinkage, etc. of the photoresist pattern. The method for forming such a photoresist pattern is suitable for the formation of a photoresist pattern used in a manufacturing step of a liquid crystal display element accompanied by a high-temperature post-baking, and is also suitable for the manufacture of an LCD using a low-temperature polycrystalline silicon glass substrate. [Embodiment] [Example] Each physical property of a positive-type photoresist composition was calculated | required as follows. (1) Sensitivity evaluation: After coating the sample (positive photoresist composition) on a glass substrate (3 60 X 4 7 0 mm2) formed with a film using a spin coater, the temperature of the hot plate was set to 1, 30, Proximity bake (20) (20) 200421020 with a 1-mm interval is first dried for 60 seconds, followed by a hot plate temperature of 2 °, and at 0.5 mm intervals The second drying was carried out for 60 seconds in the proximity of baking to form a photoresist film with a thickness of 1.5 μm. Next, a Testchart Mask (Leticul) depicting a mask pattern for reproducing a 3.0 μm line / space photoresist pattern was used, and a mirror projection analyzer MPA-600 FA (manufactured by Canon; ghi ray exposure device) was used. Exposure was performed. Secondly, an aqueous solution of 2.38% by mass of tetramethylammonium hydroxide (butyl) (^) 1) was contacted for 60 seconds, washed with water for 30 seconds, and spin-dried. Sensitivity was evaluated as the exposure amount (Eoρ exposure amount) when a 3.0 μm line / space photoresist pattern was reproduced on the substrate. (2) Evaluation of heat resistance: Treated in the same manner as the method of (1) sensitivity evaluation above, using a sample (photoresist composition) to form a photoresist pattern. Thereafter, the photoresist patterned substrate was set on a hot plate heated to 230 ° C, and the substrate was heated for 5 minutes. Thereafter, the cross-sectional shape of the photoresist pattern was observed with a S EM (scanning electron microscope) photograph. The change rate of the bottom dimension of the photoresist pattern is represented by ◎; those exceeding 3.0% and below 5.0% are represented by △; those exceeding 5.0% and below 10.0% are represented by △; those exceeding 10.0% are represented by △ X means. (3) Evaluation of outgassing: -24-(21) (21) 200421020 In the above (2) evaluation of heat resistance, 'the photoresist patterned substrate was heat-treated for 5 minutes, as shown in Figure 1, from substrate 1 Above, the generated degassing component was recovered by the bubbler 3, dissolved in the solvent (THF) 2 and the amount of degassed was analyzed by GPC method and compared. As a result, 'the degassing component is hardly observed, it is represented by 0', and the slightly observed person is represented by △, and the large number of observers are represented by X (Examples 1 to 5), (Comparative Examples 1 to 3) Examples and Comparative Examples In order to prepare a photoresist composition blended as shown in Table 1 below, sensitivity evaluation, heat resistance evaluation, and degassing evaluation were performed. The evaluation results are shown in Table 20 below. (A) The components (a) and (a2) below were used. (A) The compounding quantity of a component is 100 mass parts. In Table 1, (al) / (a2) represents a mixture of (a1) and (a2), and the following represents a mixing ratio (mass ratio). In addition, this (A) component is a mixture of the following (al) component and (a2) component in the mixing ratio described in Table 1, and is subjected to a classification treatment to adjust the M w and the content of the dinucleotide. The Mw described in Table 1 indicates the number of dimers (dinuclear content). (A 1): To a mixture of m-cresol 90 mol% and 2,3,5-trimethylphenol 100 mol% is added oxalic acid and a concentration of 37.7% by mass formaldehyde, and is carried out according to a conventional method. Mw 3 0 0 0 0 cresol novolac resin obtained by condensation reaction, M w = 3 5 0 0 obtained by classification treatment, phenolic novolac lacquer with dinuclear content of about 4.0% Resin (product name: TO-5-7, manufactured by Sumitomo Beck Iite). (A 2): In between, a mixture of cresol 35 mol / o and p. -25- (22) 200421020 benzoic acid 65 mol% was added with oxalic acid and a concentration of 37.7% by mass formic acid. The cresol novolac lacquer resin with a mass average molecular weight (Mw) of 400,000 obtained by performing a condensation reaction in a conventional method, has a Mw of 45 [) obtained by performing a classification treatment, and the phenolic dinuclear content is about 6% of cresol. Phenolic lacquer resin (product name: GTR-M 2: manufactured by Qun Rong Chemical Co., Ltd.). (B) As a component, 10 mass parts of following (bl) are used. (b 1): a phenolic hydroxyl group-containing compound (molecular weight 424) represented by the above formula (I). (C) The following (ci) or (C3) 27.5 parts by mass (c 1) is used: a compound containing a phenolic hydroxyl group represented by the above formula (11), 1 mole, and 1,2-naphthalene Product of acetic acid reaction of nitrogen- 5 -dextrin chloride 2.34 moles (average esterification rate 58.5%).

(c 3): an esterification reaction product of the compound 1 mol containing phenolic hydroxyl group represented by the above formula (V) and 1,2-naphthoquinonediazide-5 -sulfosulfonyl chloride 2.1 (Average esterification rate is 53%). (D) The component (organic solvent) is 4 Ί 2 parts by mass of the following (d). (dl): PGMEA. After dissolving the above components (A) to (D) uniformly, Megafac R-60 (product name: Dainippon Ink Chemical Industry Co., Ltd.) as a surfactant was added to 400 PPm, and a membrane filter having a pore size of 0.2 μm was used. It was filtered to prepare a positive photoresist composition. -26- (23) 200421020 [Table 1] (A) component (mixing ratio) (M w) (dimer amount) (c) component (mixing amount) a 1 / a2 c 1 Example 1 (1/1) (20000) (4.0%) al / a2 Cl example 2 (1/1) (22400) (2.5%) al / a2 cl example 3 (1.5 / 1) (24800) (1.5%) a 1 / a 2 c 1 / c 3 Example 4 (2/1) (30000) (2.5%) (2/1) al / a2 c 1 / c 3 Example 5 (1/1) (22400) (2.5%) (2/1) a 1 / a2 cl Comparative Example 1 (1/5) (10500) (4.0%) al / a2 cl Comparative Example 2 (1.2 / 1) (21500) (5.0%) a 1 / a2 c 1 / c 3 Comparative Example 3 (1.2 / 1) (21500) (5.0%) (2/1)

-27- (24) 200421020 [Table 2] Sensitivity evaluation (msec) Heat resistance evaluation Degassing evaluation Example 1 130 〇Δ Example 2 190 ◎ 〇 Example 3 280 ◎ 〇 Example 4 600 〇 Example 5 400 Δ 〇 Comparative Example 1 80 X Δ Comparative Example 2 100 XX Comparative Example 3 320 X △ [Effects of the Invention] According to the present invention as described above, a photoresist pattern capable of preventing a high-temperature post-baking step can be obtained. Photoresist composition and photoresist pattern that deform and reduce the amount of outgassing when heated at high temperature. [Schematic description] [Figure 1] In Examples 1 to 5 and Comparative Examples 1 to 3, the photoresist pattern heat treatment is used to evaluate the heat resistance of the positive photoresist composition. Component recovery device. Comparison Table of Main Components 1 Substrate -28- (25) 200421020 2 Dissolve all 3 Bubblers

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Claims (1)

200421020 拾 Pick up, patent application scope 1. A positive photoresist composition, characterized in that it contains (A) a mass average molecular weight (Mw) converted to polystyrene according to gel permeation chromatography of 20,000 or more and a dinuclear body An alkali-soluble phenolic lacquer resin having a content of 4% or less, (B) a compound containing a phenolic hydroxyl group having a molecular weight of 1,000 or less, (C) a compound containing a naphthoquinonediazide group, and (D) an organic solvent. 2. The positive type photoresist composition according to item 1 of the scope of patent application, wherein the (A) component is a phenolic lacquer resin (A1) containing a mass average molecular weight (Mw) converted to polystyrene of 30,000 to 40,000. 3. The positive type photoresist composition according to item 1 of the patent application range, wherein the component (A) is a phenolic lacquer resin containing a mass average molecular weight (Mw) converted to polystyrene of 3,000 to 7,000. 4 · The positive photoresist composition according to item 1 of the patent application range, wherein the component (A) is a phenolic lacquer resin (A1) component containing a mass average molecular weight (Mw) of 30,000 to 40,000 converted to polystyrene And the phenolic lacquer resin component (A2) converted to polystyrene with a mass average molecular weight (Mw) of 3000 to 7000, and represents the mass ratio (Al) of the content of the (A1) component to the content of the (A2) component / (A2) 値 is 1/1 to 5/1. 5. The positive photoresist composition according to item 2 of the patent application scope, wherein the (A 1) component contains a constituent unit derived from m-cresol and derived from 2,3,5-trimethylphenol Constituent units. 6 · The positive photoresist composition according to item 3 of the patent application, wherein the (A2) component contains a constituent unit derived from m-cresol and p-methyl-30- (2) (2) 200421020 A constituent unit derived from phenol. 7. The positive photoresist composition according to item 1 of the patent application range, wherein the component (B) is a compound containing a phenolic hydroxyl group represented by the following formula (I) 8. The positive photoresist composition according to item 1 of the application, wherein the component (C) is a compound containing a phenolic hydroxyl group represented by the following formula (Π) and 1,2-naphthoquinonediazide Esterification reaction product (C1) of a sulfonic acid compound. HO 〇H OH (Π) Ο ο 9. The positive photoresist composition according to item 1 of the patent application range, wherein the (C) component is a compound containing a phenolic hydroxyl group represented by the following formula (IΠ) and Esterification reaction product of 1,2-naphthoquinonediazidesulfonic acid compound (C2) -31-200421020 [Wherein 'R1 ~ R8 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms; R9 to R11 each independently represent a hydrogen atom or an alkyl group having several carbon atoms; q is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a residue represented by the following chemical formula (IV) (In the formula, R12 and R13 are each independently a hydrogen atom, a halogen atom, a radical having 1 to 6 carbon atoms, a radical having 1 to 6 carbon atoms, or a circle radical having 3 to 6 carbon atoms; c is an integer representing 1 to 3), or Q is a combination with R9, and R9, and the carbon atoms between Q and R9 together form a cycloalkyl group having 3 to 6 carbon chains; a and b represent 1 to 3 An integer; d is an integer representing 0 to 3; η is an integer representing 0 to 3]. 10. The positive type photoresist composition according to item 1 of the scope of patent application, wherein the component (C) is a compound containing a phenolic hydroxyl group represented by the following formula (V) and 1,2-naphthoquinonediazide Esterification reaction product of a sulfonic acid compound (C3). -32- (V) (4) 200421020 ch3 h3c 11. For example, the positive type photoresist composition of the scope of application for patent No. 1 is used for the manufacture of liquid crystal display elements. 12. A method for forming a photoresist pattern, which is characterized by having a step of pre-baking a photoresist film after coating a positive photoresist composition such as the first item in the scope of patent application on the substrate. Photoresist pattern forming step of selective exposure, and photoresist pattern formation in the step of forming a photoresist pattern on the substrate by performing a development process using an alkaline aqueous solution on the photoresist film after the selective exposure. In a method, the substrate is a low-temperature polycrystalline glass substrate having a low-temperature polycrystalline silicon film on a glass substrate. 13. The method for forming a photoresist pattern according to item 12 of the scope of application for a patent, which comprises a step of baking the photoresist pattern after the development process at a high temperature of 200 t or more. 1 4 · A liquid crystal display element, which is manufactured by using a positive type photoresist composition as described in the first patent application. -33-