JP2010085567A - Resin composition for photoresist - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for a photoresist having good sensitivity and resolution, high heat resistance, high film retaining property and other characteristics comparable to a general-purpose resin composition. <P>SOLUTION: The resin composition for a photoresist contains a high-orthonovolac phenol resin obtained by the reaction of phenols and aldehydes in the presence of an acid catalyst at a temperature of 110 to 220°C, a polyamide phenol resin, a naphthoquinone azide derivative and a solvent. It is preferable that the ratio of the high-orthonovolac phenol resin (wt) to the polyamide phenol resin by weight ranges from 95:5 to 50:50, the phenols are mixtures of metacresol and paracresol, and the ratio of metacresol to paracresol ranges from 60:40 to 30:70. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photoresist resin composition.

  A fine circuit pattern such as a liquid crystal display device circuit or a semiconductor integrated circuit is obtained by uniformly coating or applying a photoresist composition on an insulating film or conductive metal film formed on a substrate, and in the presence of a mask of a predetermined shape. The coated photoresist composition is exposed and developed to produce a pattern of the desired shape. Thereafter, the metal film or the insulating film is removed using the patterned photoresist film as a mask, and then the remaining photoresist film is removed to form a fine circuit on the substrate. Such a photoresist composition is classified into a negative type and a positive type depending on whether the exposed portion or the photoresist film is soluble or insoluble.

  In general, a positive photoresist composition uses a photosensitizer having a quinonediazide group such as a naphthoquinonediazide compound and an alkali-soluble resin (for example, a novolac-type phenolic resin). A positive photoresist composition having such a composition exhibits a high resolving power by developing with an alkaline solution after exposure, and is used for the manufacture of semiconductors such as IC and LSI, the manufacture of liquid crystal display screen devices such as LCDs, and the manufacture of printing masters. It's being used. In addition, novolak-type phenolic resins have high heat resistance due to the structure having many aromatic rings against plasma dry etching. Until now, novolak-type phenolic resins and naphthoquinone diazide photosensitizers have been used. Numerous positive photoresists have been developed and put into practical use and have achieved great results.

  The practical characteristics of the photoresist composition for liquid crystal display device circuits are the sensitivity, development contrast, resolution, adhesion to the substrate, residual film ratio, heat resistance, circuit line width uniformity ( CD uniformity). In particular, improvement in sensitivity is inevitably required due to the long exposure time in the production line due to the large area of the substrate, which is a feature of the thin film transistor liquid crystal display device. In addition, the sensitivity and the remaining film ratio are inversely proportional, and the higher the sensitivity, the lower the remaining film ratio tends to decrease.

  A novolak type phenol resin obtained by reacting m / p-cresol and formaldehyde in the presence of an acid catalyst is generally used for a positive type photoresist for a liquid crystal display device circuit. In order to adjust or improve the characteristics of the photoresist, studies have been made on the ratio of m / p-cresol used as a raw material phenol, the molecular weight of the phenol resin, the molecular weight distribution, and the like. Patent Document 1 discloses the use of a method of fractionating a novolak resin in order to improve photoresist characteristics, and the above contents are well known to those skilled in the art. . In general, improvement in the sensitivity of the photoresist is achieved by lowering the molecular weight of the novolak resin, but this method deteriorates the heat resistance, reduces the remaining film ratio of the unexposed area, There is a problem that a difference in dissolution rate cannot be obtained, resulting in a decrease in development contrast between the exposed area and the unexposed area, which in turn causes a decrease in resolution. On the other hand, when the molecular weight of the novolak resin is increased, the heat resistance and resolution are improved, but the sensitivity is lowered. That is, trying to improve one causes a very serious inconvenience that the other gets worse. Despite various attempts to date, photo resist compositions for liquid crystal display devices such as sensitivity, residual film ratio, development contrast, resolution, adhesion to substrate, circuit line width uniformity, etc. A variety of photoresist compositions for liquid crystal display circuits suitable for each industrial process have not been developed without sacrificing any one of the preferable characteristics of the product, and the demand for this continues.

Special table 2002-508415 gazette

  An object of the present invention is to provide a resin composition for a photoresist having good sensitivity and resolution, high heat resistance, high residual film property, and other characteristics that are not inferior to those of general-purpose ones.

［２］ 上記ハイオルソノボラック型フェノール樹脂と一般式（１）で示されるポリアミドフェノール樹脂の比率（ｗｔ）が９５：５から５０：５０である上記［１］記載のフォトレジスト用樹脂組成物。
［３］ フェノール類がメタクレゾールとパラクレゾールの混合物である上記［１］又は［２］記載のフォトレジスト用樹脂組成物。
［４］ メタクレゾールとパラクレゾールの比率が６０：４０から３０：７０である上記［３］記載のフォトレジスト用樹脂組成物。 Such an object is achieved by the following present invention [1] to [4].
[1] A high ortho novolac type phenol resin obtained by reacting phenols and aldehydes in the presence of an acid catalyst at a temperature of 110 to 220 ° C., a polyamide phenol resin represented by the following general formula (1), naphtho A resin composition for a photoresist, comprising a quinonediazide derivative and a solvent.

[2] The resin composition for a photoresist according to the above [1], wherein the ratio (wt) of the high-ortho novolak type phenol resin to the polyamide phenol resin represented by the general formula (1) is 95: 5 to 50:50.
[3] The resin composition for photoresists according to the above [1] or [2], wherein the phenol is a mixture of metacresol and paracresol.
[4] The resin composition for photoresists according to the above [3], wherein the ratio of metacresol to paracresol is 60:40 to 30:70.

  According to the present invention, it is possible to provide a resin composition for a photoresist having good sensitivity and resolution, high heat resistance, high residual film property, and other characteristics that are not inferior to those of general-purpose ones.

  The present invention is described in detail below.

  The present invention relates to a resin composition for photoresist. First, the resin used for the photoresist resin composition of the present invention will be described.

  The high ortho novolac type phenol resin used in the present invention is a resin obtained by reacting phenols and aldehydes in the presence of an acid catalyst at a temperature of 110 to 220 ° C. When the reaction is first performed at a high temperature of 110 to 220 ° C., the reaction in the vicinity of the phenolic hydroxyl group occurs preferentially, and therefore, a resin having a higher ortho-ratio than that of a normal one is easily obtained. The reaction is preferably carried out at 110-220 ° C, more preferably 120-150 ° C. Although it does not specifically limit as phenols used for the said novolak type phenol resin, For example, phenol, metacresol, orthocresol, paracresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6 -Xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,4-trimethylphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, 2,4,5-trimethylphenol 3,4,5-trimethylphenol, ethylphenol, propylphenol, butylphenol, octylphenol, nonylphenol, 1-naphthol, 2-naphthol, phenylphenol and the like.

Although it does not specifically limit as aldehydes used for the said novolak type phenol resin, For example, formaldehyde, acetaldehyde, propyl aldehyde, butyraldehyde, benzaldehyde, salicylaldehyde, etc. are mentioned.
Among these, formaldehyde, paraformaldehyde, acetaldehyde, and salicylaldehyde are preferable. Thereby, when used as a photoresist composition, high sensitivity can be achieved. When formaldehyde is used, the formaldehyde source is not particularly limited, but any formaldehyde can be used as long as it generates formaldehyde, such as formalin (aqueous solution), paraformaldehyde, hemi-formal with alcohols, and trioxane.

  An acid catalyst is generally used for the reaction of the phenols and aldehydes. Although it does not specifically limit as an acid catalyst for synthesize | combining the high ortho novolak type phenol resin of this invention, For example, weak acids, such as organic carboxylic acids, such as an oxalic acid and an acetic acid, are mentioned. Among these, it can also be used individually or in mixture of 2 or more types. Although the usage-amount of an acid catalyst is not specifically limited, It is preferable that it is 0.01-5 weight% with respect to phenols. Further, when a photoresist resin is used in the photoresist composition, a small amount of catalyst remains in the resin because of the characteristics of the photoresist. Of course, in the process of synthesizing the resin, it may be removed by a general removal method (neutralization, water washing, filter filtration, etc.). Moreover, as a reaction solvent used for this invention, it is a moderately non-polar solvent, for example, hexane, benzene, xylene etc. are mentioned. By using these, it becomes possible to keep the ortho-ratio of the resin high.

The ortho-formation ratio of the high ortho novolak type phenol resin used in the present invention is preferably 20-40%, more preferably 25-35%. These ortho-conversion rates can generally be analyzed using ¹³ C-NMR. This makes it possible to maintain high sensitivity and a high residual film ratio when used as a photoresist.

  When metacresol and paracresol are used as the phenols used in the present invention, the ratio of metacresol is preferably 30 to 60%, more preferably 40 to 50%. This makes it possible to maintain high reactivity with the naphthoquinonediazide derivative while maintaining high sensitivity when used as a photoresist, and to increase the remaining film ratio when used as a photoresist.

As the novolak type phenol resin used in the present invention, the weight average molecular weight measured by GPC is preferably 1000 to 20000, more preferably 3000 to 10000, and the weight average molecular weight is within the above range. , Heat resistance and residual film properties can be improved. The weight average molecular weight was calculated based on a calibration curve prepared using a polystyrene standard. GPC measurement can be performed using tetrahydrofuran as an elution solvent, a flow rate of 1.0 ml / min, and a column temperature of 40 ° C. using a differential refractometer as a detector. Examples of devices that can be used include:
1) Body: "HLC-8020" manufactured by TOSOH
2) Detector: “UV-8011” manufactured by TOSOH with wavelength set to 280 nm
3) Analytical column: “SHODEX KF-802, KF-803, KF-805” manufactured by Showa Denko KK can be used.

  The polyamide phenol resin necessary for the present invention is a method described in Japanese Patent Application Laid-Open No. 60-223824, such as a method in which a dicarboxylic acid is acid chlorided using thionyl chloride and the like and condensed with dihydroxydiamine, or a dicarboxylic acid and dihydroxy It can be obtained by a method of condensing diamine with a condensing agent such as dicyclohexylcarbodiimide.

Examples of the corresponding dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, 3,3′-diphenyldicarboxylic acid, 3,4′-diphenyldicarboxylic acid, 4,4′-diphenyldicarboxylic acid, and 3,3′-diphenylether. Dicarboxylic acid, 3,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 2,2-bis (4-carboxyphenyl) hexafluoropropane, 3,3'-benzophenone dicarboxylic acid, 3,4'- Examples include benzophenone dicarboxylic acid, 4,4′-benzophenone dicarboxylic acid, 3,3′-diphenyl sulfone dicarboxylic acid, 3,4′-diphenyl sulfone dicarboxylic acid, 4,4′-diphenyl sulfone dicarboxylic acid, and the like. In use, one kind or a mixture of two or more kinds may be used.

Examples of the dihydroxydiamine include 2,4-dihydroxy-m-phenylenediamine, 2,5-dihydroxy-p-phenylenediamine, 3,3′-diamino-4,4′-dihydroxydiphenyl, and 4,4′-. Diamino-3,3′-dihydroxydiphenyl, 3,4′-diamino-3,4′-dihydroxydiphenyl, 3,3′-diamino-4,4′-dihydroxydiphenyl ether, 4,4′-diamino-3,3 '-Dihydroxydiphenyl ether, 3,4'-diamino-3,4'-dihydroxydiphenyl ether, 3,3'-diamino-4,4'-dihydroxydiphenylhexafluoropropane, 4,4'-diamino-3,3'- Dihydroxydiphenylhexafluoropropane, 3,4'-diamino-3,4'-di Droxydiphenylhexafluoropropane, 3,3′-diamino-4,4′-dihydroxybenzophenone, 4,4′-diamino-3,3′-dihydroxybenzophenone, 3,4′-diamino-3,4′-dihydroxy Benzophenone, 3,3′-diamino-4,4′-dihydroxydiphenyl sulfone, 4,4′-diamino-3,3′-dihydroxydiphenyl sulfone, 3,4′-diamino-3,4′-dihydroxydiphenyl sulfone, etc. Is mentioned. In use, one kind or a mixture of two or more kinds may be used.

  In the case of using the method of reacting after chlorination, a step of washing with water and washing with an aqueous alkali solution may be introduced after the reaction in order to reduce the amount of residual halogen. Further, when a condensing agent such as dicyclohexylcarbodiimide is used, filtration, water washing treatment and the like may be repeated.

As the polyamide phenol resin used in the present invention, the weight average molecular weight measured by GPC is preferably 1000 to 40000, more preferably 3000 to 30000. By making the weight average molecular weight in the above range, the sensitivity, Heat resistance and residual film properties can be improved. The weight average molecular weight was calculated based on a calibration curve prepared using a polystyrene standard. GPC measurement can be performed using tetrahydrofuran as an elution solvent, a flow rate of 1.0 ml / min, and a column temperature of 40 ° C. using a differential refractometer as a detector. Examples of devices that can be used include:
1) Body: "HLC-8020" manufactured by TOSOH
2) Detector: “UV-8011” manufactured by TOSOH with wavelength set to 280 nm
3) Analytical column: “SHODEX KF-802, KF-803, KF-805” manufactured by Showa Denko KK can be used.

  It goes without saying that the novolak type phenol resin is as described above, but the polyamide phenol resin, which is a polybenzoxazole precursor, has a phenolic hydroxy group in its structural unit, so it can be combined with a diazonaphthoquinone compound. A clear and fine positive pattern can be easily formed by alkali development. In addition, since the polyamide phenol resin has a rigid main chain skeleton, it has excellent heat resistance and is more advantageous than the novolac type phenol resin in this respect. By containing them in a certain ratio, it is possible to improve the heat resistance when used as a photoresist.

  In addition, since the polyamidephenol resin is a polybenzoxazole precursor, when it is used as a photoresist, the development is completed, and heat is applied to the patterned resin composition at 200 ° C. or more, so that polyamidophenol poly The heat resistance can be further improved by benzoxazolation. Since the polymerization proceeds in the composition after the patterning is completed, the heat resistance as a photoresist can be further improved.

  Next, as the naphthoquinone diazide derivative, for example, a diazonaphthoquinone-5-sulfonic acid chloride or a diazonaphthoquinone-4-sulfonic acid chloride derivative in a ballast such as an alcohol or phenol derivative and a solvent such as tetrahydrofuran or dioxane can be used such as triethylamine. It can be obtained by performing esterification in the presence of a basic catalyst. As the chemical structure of this ballast, compounds having various chemical structures can be used. For example, polyhydroxybenzophenone such as hydroxybenzophenone and dihydroxybenzophenone, naphthol, hydroquinone, pyrogallol, bisphenol A, p-cresol polymer, and derivatives thereof. In this reaction, the esterification rate can be controlled by adjusting the molar ratio of diazonaphthoquinone sulfonic acid chloride to ballast. These naphthoquinone diazides may be one kind or a mixture of two or more kinds.

  The solvent to be blended in the composition of the present invention is not particularly limited as long as it dissolves the photoresist resin and naphthoquinonediazide. In the present invention, these components are used by dissolving in a solvent. Solvents include N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol Monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butylene glycol acetate, 1,3-butylene glycol 20-3-monomethyl ether, methyl pyruvate, ethyl pyruvate, methyl-3-methoxypro Pionate etc. can be used individually or in mixture.

  In addition to the above-described components, the composition of the present invention may contain various additives such as stabilizers such as antioxidants, plasticizers, surfactants, adhesion improvers, and dissolution accelerators as necessary. An agent may be used.

  The method for preparing the composition of the present invention is not particularly limited, but when no filler or pigment is added to the composition, the above components may be mixed and stirred in the usual manner. In the case of adding, for example, it may be dispersed and mixed using a dispersing device such as a dissolver, a homogenizer, or a three roll mill. Moreover, you may further filter using a mesh filter, a membrane filter, etc. as needed.

  By exposing the composition of the present invention thus obtained through a mask, a structural change occurs in the composition in the exposed portion, and the solubility in an alkali developer is promoted. be able to. On the other hand, in the non-exposed area, low solubility in an alkali developer is maintained, so that a resist function can be imparted due to the difference in solubility thus generated.

Next, the procedure for synthesizing the photoresist resin of the present invention will be described. The synthesis method described below is an example and is not particularly limited thereto.
First, a novolac type phenol resin is synthesized. The synthesis can be carried out by adding phenols and an acid catalyst to a pressure reaction vessel equipped with a stirrer, a thermometer and a heat exchanger, and adding aldehydes. Examples of the acid catalyst include oxalic acid. In the above reaction, the reaction temperature and time may be appropriately set depending on the reactivity of the raw materials, but in order to synthesize stably and economically, the reaction time is 2 to 10 hours and the reaction temperature is 110 to 220. Although it is preferable to set it as ° C, it is more preferable to set it as 120-150 ° C. Moreover, a reaction solvent can also be used if necessary.

  Further, after completion of the reaction, for example, a basic compound may be added for neutralization in order to remove the acid catalyst, and the neutralized salt may be removed by washing with water. The amount and number of times of washing water are not particularly limited, but the number of times of washing is preferably about 1 to 5 times from the viewpoint of removing the neutralized salt in the resin to a level that does not substantially affect the washing. The washing temperature is not particularly limited, but is preferably 40 to 95 ° C. from the viewpoint of the removal efficiency of neutralized salt and workability.

After completion of the above reaction or washing with water, dehydration / demonomerization is performed under normal pressure and / or under reduced pressure. The degree of reduced pressure at which dehydration / demonomer is performed is not particularly limited, but is preferably about 0.1 to 30 × 10 ³ Pa. The temperature for taking out from the reaction vessel after dehydration / demonomer is not particularly limited, but can be appropriately set depending on the characteristics and viscosity of the resin. From the viewpoint of the stability of the resin, 150 to 250 ° C. is preferable. In this manner, a high ortho novolac type phenol resin which is the basis of the photoresist resin of the present invention is obtained.

  Next, the manufacturing method of the polyamide phenol resin of this invention is demonstrated. A polyamidephenol resin can be synthesized by reacting the dicarboxylic acid with thionyl chloride in an organic solvent to react with acid chloride and dihydroxyamine. The reaction temperature is preferably set in the range of 50 to 100 ° C. If the temperature is lower than 50 ° C., the progress of the reaction is remarkably slow. If the temperature is higher than 100 ° C., the resulting polyamidephenol is closed to initiate conversion to polybenzoxazole, which is not preferable. The reaction time may be 1 to 20 hours, preferably 2 to 10 hours.

  In the reaction of dicarboxylic acid and dihydroxyamine, it is preferable to set the ratio of the two in a molar ratio of dicarboxylic acid: dihydroxyamine = 1.2: 1.0 to 1.0: 1.2, particularly equimolar. It is preferable to react.

  The solution after completion of the reaction is further diluted by adding an organic solvent and added dropwise to water with stirring. Water is removed and vacuum drying is performed in the range of 50 ° C. to 100 ° C. to obtain the target polyamidephenol resin.

  Hereinafter, the present invention will be described with reference to synthesis examples and examples. However, the present invention is not limited by these synthesis examples and examples. Further, “parts” and “%” described in the synthesis examples, examples and comparative examples all represent “parts by weight” and “% by weight”. However, the concentration (%) of the formalin aqueous solution is excluded.

1. Synthesis of high ortho novolac type phenolic resin (Synthesis Example 1)
A 3 L four-necked flask equipped with a stirrer, a thermometer, and a heat exchanger was charged with 600 parts of m-cresol, 400 parts of p-cresol, 200 parts of hexane, and 5 parts of oxalic acid, and the temperature was raised to 130 ° C. Thereafter, 527 parts of 37% formalin was gradually added over 1 hour, followed by reaction for 4 hours while dehydrating. Thereafter, dehydration was performed under normal pressure to an internal temperature of 170 ° C., and dehydration / demonomerization was further performed to 200 ° C. under a reduced pressure of 9.3 × 10 ³ Pa to obtain 950 parts of phenol resin B having a weight average molecular weight of 4200.
(Comparative Synthesis Example 2)
37% formalin aqueous solution with respect to 1000 parts of phenol mixed with m-cresol and p-cresol in a molar ratio (m-cresol: p-cresol) = 6: 4 in the same apparatus as in Synthesis Example 1. 520 parts and 2 parts of oxalic acid were charged and reacted under reflux for 4 hours. Thereafter, dehydration was performed under normal pressure to an internal temperature of 170 ° C., and dehydration / demonomerization was further performed to 200 ° C. under a reduced pressure of 9.3 × 10 ³ Pa to obtain 770 parts of phenol resin D having a weight average molecular weight of 6300.

2. Evaluation of high ortho novolac type phenolic resin
Measurement of orthorization rate (o-o 'bond rate) by ¹³ C-NMR Using nuclear magnetic resonance spectroscopy (NMR, JNM-AL300 manufactured by JEOL Datum Co., Ltd.) , P-p ′, and o-o ′ were determined. As measurement conditions, the number of integrations was 10,000. The orthorization ratio of the resin of Synthesis Example 1 was 25%. The orthorization ratio of the resin of Comparative Synthesis Example 2 was 16%.

3. Synthesis of polyamide phenol resin (Synthesis Example 3)
70 parts of 4,4′-diphenyl ether dicarboxylic acid and 4.5 parts of N, N-dimethylaminopyridine are dissolved in 300 parts of γ-butyrolactone in a 3 L 4-neck flask equipped with a stirrer, a thermometer and a heat exchanger. 100 parts of thionyl chloride was added dropwise over 1 hour, followed by reaction for 1 hour. Thereto, 600 g of a 120 g γ-butyrolactone solution of 3,3-diamino-4,4′-dihydroxydiphenylhexafluoropropane was added dropwise at room temperature over 1 hour, and then reacted for 6 hours. 1000 g of γ-butyrolactone was added to the solution after completion of the reaction, and the mixture was added dropwise to water with stirring. After removing the water, vacuum drying was performed at 60 ° C. for 3 hours to obtain 50 parts of a polyamide phenol resin having a weight average molecular weight of 8200. .

3. Preparation of photoresist composition (Example 1)
21 parts of the novolak-type phenol resin obtained in Synthesis Example 1 and 9 parts of the polyamidephenol resin obtained in Synthesis Example 3 2,3,4,4′-tetrahydroxybenzophenone and 6-diazo-5,6-dihydro- After dissolving 6 parts of ester with 5-oxo-naphthalene-1-sulfonic acid in 150 parts of γ-butyrolactone, it was filtered using a membrane filter having a pore size of 1.0 μm to prepare a photoresist composition.
(Example 2)
27 parts of the novolak type phenol resin obtained in Synthesis Example 1 and 3 parts of the polyamide phenol resin obtained in Synthesis Example 3 2,3,4,4'-tetrahydroxybenzophenone and 6-diazo-5,6-dihydro- After dissolving 6 parts of ester with 5-oxo-naphthalene-1-sulfonic acid in 150 parts of γ-butyrolactone, it was filtered using a membrane filter having a pore size of 1.0 μm to prepare a photoresist composition.
(Example 3)
10 parts of the novolak type phenol resin obtained in Synthesis Example 1 and 20 parts of the polyamide phenol resin obtained in Synthesis Example 3 2,3,4,4′-tetrahydroxybenzophenone and 6-diazo-5,6-dihydro- After dissolving 6 parts of ester with 5-oxo-naphthalene-1-sulfonic acid in 150 parts of γ-butyrolactone, it was filtered using a membrane filter having a pore size of 1.0 μm to prepare a photoresist composition.

(Comparative Example 1)
30 parts of a phenol resin for photoresist obtained in Synthesis Example 1, 2,3,4,4′-tetrahydroxybenzophenone and 6-diazo-5,6-dihydro-5-oxo-naphthalene-1-sulfonic acid After dissolving 6 parts of ester in 150 parts of γ-butyrolactone, it was filtered using a membrane filter having a pore size of 1.0 μm to prepare a photoresist composition.
(Comparative Example 2)
30 parts of a phenol resin for photoresist obtained in Synthesis Example 1, 2,3,4,4′-tetrahydroxybenzophenone and 6-diazo-5,6-dihydro-5-oxo-naphthalene-1-sulfonic acid After dissolving 6 parts of ester in 150 parts of propylene glycol monomethyl ether acetate (PGMEA), it was filtered using a membrane filter having a pore size of 1.0 μm to prepare a photoresist composition.
(Comparative Example 3)
21 parts of the novolak type phenol resin obtained in Comparative Synthesis Example 2 and 9 parts of the polyamide phenol resin obtained in Synthesis Example 3 2,3,4,4'-tetrahydroxybenzophenone and 6-diazo-5,6-dihydro After dissolving 6 parts of ester with -5-oxo-naphthalene-1-sulfonic acid in 150 parts of γ-butyrolactone, it was filtered using a membrane filter having a pore size of 1.0 μm to prepare a photoresist composition.

  Using the photoresist compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3, the following characteristic evaluation was performed. The results are shown in Table 1.

6). Characteristics Evaluation Method (1) Heat Resistance Evaluation Method A silicon wafer that has been treated with hexamethyldisilazane is coated with a spin coater so that the film thickness when dried is 1.5 μm, and is heated on a hot plate at 110 ° C. for 90 seconds. And dried. Thereafter, exposure was performed through a test chart mask using a reduction projection exposure apparatus, and development was performed for 60 seconds using a developer (2.38% tetramethylammonium hydroxide aqueous solution). When the obtained silicon wafer was left on a hot plate with a different temperature for 3 minutes and the shape of the resist pattern on the silicon wafer was observed with a scanning electron microscope, a normal resist pattern could not be obtained. The temperature was defined as the heat resistant temperature.

(2) Remaining film ratio measuring method The photoresist composition was applied to a thickness of about 1 μm on a 3 inch silicon wafer with a spin coater, and dried on a hot plate at 110 ° C. for 100 seconds. The wafer was immersed in a developing solution (2.38% tetramethylammonium hydroxide aqueous solution) for 60 seconds, washed with water, and dried on a hot plate at 110 ° C. for 100 seconds. The ratio of the film thickness after development to the film thickness before development was expressed as a percentage, and was defined as the remaining film ratio. As a result, the degree of remaining film (resistance) when used as a photosensitizer and a photoresist can be understood, and the higher the numerical value, the higher the remaining film rate.

(3) Sensitivity measurement method The photoresist composition was applied to a 3-inch silicon wafer with a spin coater to a thickness of about 1 μm and dried on a 110 ° C. hot plate for 100 seconds. Then repeated test chart mask on the silicon ^{wafer, 20mJ / cm 2, 40mJ /} cm 2, 60mJ / cm 2 of ultraviolet irradiation, respectively, 90 using a developing solution (2.38% tetramethylammonium hydroxide aqueous solution) Developed for seconds. The obtained pattern was evaluated according to the following criteria by observing the pattern shape with a scanning electron microscope.
A An image can be formed at 20 mJ / cm ² or less.
B 20 mJ / cm ² than the image can be formed at 40 mJ / cm ² or less.
C 40 mJ / cm ² than the image can be formed at 60 mJ / cm ² or less.
(4) Measurement of resolution The above-prepared photoresist composition was applied onto a silicon substrate using a spin coater and pre-baked at 110 ° C. for 100 seconds to form a resist film having a thickness of 1.5 μm. This was exposed using ultraviolet rays through a pattern mask in which a line width of 100 to 1 μm was engraved. Immediately after the exposure, the film was developed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds, washed with water and dried to obtain a positive pattern. At that time, the dimension of the smallest photoresist pattern that can be resolved with a constant exposure amount is defined as the resolution.
From the result of Table 1, Examples 1-3 are the compositions for photoresists of this invention using the resin for photoresists of this invention, and were excellent compared with Comparative Examples 1-3 which do not use this. It was proved that the film had a residual film ratio, sensitivity and heat resistance.

  The phenolic resin for photoresist and the photoresist composition of the present invention have good thermal stability, high sensitivity, high resolution, and high residual film properties. It can be suitably used for circuit manufacture.

Claims (4)

A high-ortho novolak type phenol resin obtained by reacting phenols and aldehydes in the presence of an acid catalyst at a temperature of 110 to 220 ° C., a polyamide phenol resin represented by the following general formula (1), a naphthoquinone diazide derivative, A resin composition for a photoresist, comprising a solvent.

  The resin composition for a photoresist according to claim 1, wherein the ratio (wt) of the high-ortho novolak type phenol resin to the polyamide phenol resin represented by the general formula (1) is 95: 5 to 50:50.   The resin composition for photoresists according to claim 1 or 2, wherein the phenol is a mixture of metacresol and paracresol.   The resin composition for a photoresist according to claim 3, wherein the ratio of metacresol to para-cresol is 60:40 to 30:70.