KR20130100989A - Resin composition for photoresist - Google Patents

Abstract

In particular, the present invention provides a resin composition for photoresists that has high heat resistance, has good sensitivity and resolution, high residual film resistance, and is inferior to general-purpose ones for other properties. As a resin composition for photoresists containing a phenol resin, a cyclic olefin resin, and a naphthoquinone diazide group-containing compound, it is preferable that the cyclic olefin resin is a norbornene resin, and the norbornene resin is an acid group, It is preferable that it has a phenol group especially and is a molecular weight 1000-50000 Daltons.

Description

Resin composition for photoresist {RESIN COMPOSITION FOR PHOTORESIST}

The present invention relates to a resin composition for photoresist.

This application claims priority in August 27, 2010 based on Japanese Patent Application No. 2010-190880 for which it applied to Japan, and uses the content for it here.

A fine circuit pattern, such as a liquid crystal display device circuit or a semiconductor integrated circuit, may uniformly coat or apply a photoresist composition to an insulating film or a conductive metal film formed on a substrate, and apply the photoresist composition coated in the presence of a mask having a predetermined shape. By exposing and developing, it forms in the pattern of the target 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 by the part to be exposed and the photoresist film being soluble or insoluble.

Generally, the photosensitive agent which has quinonediazide groups, such as a naphthoquinone diazide compound, and alkali-soluble resin (for example, novolak-type phenol resin) are used for a positive type photoresist composition. The positive photoresist composition composed of such a composition exhibits high resolution by developing with an alkaline solution after exposure, and is used for manufacturing semiconductors such as IC and LSI, manufacturing liquid crystal display devices such as LCDs, and manufacturing printing originals. It is becoming. Moreover, the novolak-type phenolic resin also has high heat resistance resulting from the structure which has many aromatic rings with respect to plasma dry etching, and many positives containing a novolak-type phenol resin and a naphthoquinone diazide type photosensitive agent so far are Type photoresists have been developed and put to practical use and are achieving great results.

Important characteristics in practical use of the photoresist composition for liquid crystal display circuits are the sensitivity, development contrast, resolution, adhesion to the substrate, residual film ratio, heat resistance, and circuit uniformity of the formed resist film (CD uniformity). In particular, the improvement of the sensitivity is necessarily required because of 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, since the sensitivity and the residual film ratio are inversely related, when the sensitivity is high, the residual film ratio tends to decrease.

As a positive photoresist for liquid crystal display circuits, novolak-type phenol resins obtained by reacting m / p-cresol and formaldehyde in the presence of an acid catalyst are generally used. And in order to adjust or improve the characteristic of a photoresist, the ratio of the m / p-cresol used as raw material phenols, the molecular weight of a phenol resin, molecular weight distribution, etc. have been examined. In addition, Patent Document 1 discloses the use of a method of treating a novolak resin in order to improve photoresist properties, and the above contents are widely known to those skilled in the art.

In general, the improvement of the sensitivity of the photoresist is achieved by lowering the molecular weight of the novolak resin. However, in this method, the heat resistance deteriorates, the remaining film ratio of the unexposed portion is lowered, or the dissolution rate difference between the exposed portion is not sufficiently obtained, resulting in a decrease in the development contrast of the exposed portion and the unexposed portion. As a result, a problem of a drop in resolution occurs. On the other hand, when the molecular weight of a novolak resin is made high, heat resistance and resolution will improve, but the fall of the sensitivity of a resist film will arise. In other words, if one wants to improve, a very serious problem occurs that the other deteriorates.

So far, various improvements have been attempted on this problem. However, still without sacrificing any of the desirable properties of the photoresist composition for liquid crystal display circuits, such as sensitivity, residual film ratio, development contrast, resolution, adhesion to the substrate, circuit line width uniformity, etc. Various photoresist compositions for liquid crystal display circuits, which are possible and can be applied to respective industrial processes, have not been developed. Therefore, the demand for this continues.

Japanese Patent Publication No. 2002-508415

An object of the present invention is to provide a resin composition for photoresist that has particularly high heat resistance, has good sensitivity, resolution, and high residual film resistance, and is inferior to general-purpose ones for other properties.

The resin composition for photoresists of one embodiment of the present invention is a resin composition for photoresists comprising a novolac phenol resin, a cyclic olefin resin, and a photosensitizer made of a naphthoquinone diazide group-containing compound.

In the resin composition for photoresist, norbornene resin may be sufficient as the said cyclic olefin resin.

In the resin composition for photoresists, the cyclic olefin resin may be a cyclic olefin resin containing a repeating unit represented by the following General Formula (1).

[Formula 1]

In the formula (1), X is O, CH ₂ , CH ₂ CH ₂ It will of which, n is an integer of ^{0 ~ 5, R 1 ~ R} 4 Are each independently selected from a monovalent organic group having 1 to 30 carbon atoms or hydrogen which may contain O and / or F in the structure, and R ¹ to R ⁴ may be different among the repeats of the monomer, At least one of R ¹ to R ⁴ has an acidic group.

In the said resin composition for photoresists, the said acidic group may be 1 or more groups chosen from the group which consists of a carboxyl group, a phenol group, a fluoro alcohol group, and a sulfoamide group.

In the resin composition for photoresists, the weight average molecular weight of the cyclic olefin resin may be 1000 to 500,000 Daltons.

In the said resin composition for photoresists, 1-90 weight% of mixing ratios of the said cyclic olefin resin with respect to the said phenol resin may be sufficient.

According to this invention, the resin composition for photoresists which has high heat resistance, has favorable sensitivity, a resolution, and a high residual film property, and is not inferior to general purpose also about other characteristics can be provided.

Hereinafter, the present invention will be described in detail.

The present invention relates to a resin composition for photoresist.

The novolak-type phenol resin used in the production of the photoresist composition of the present invention is synthesized by condensation reaction of phenols and aldehydes in the presence of an acid catalyst based on the conventional method.

Although it does not specifically limit as phenols used by the said reaction, For example, cresols, such as a phenol, o-cresol, m-cresol, p-cresol, 2, 3- xylenol, 2, 4- xylenol, Xylols such as 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, o-ethylphenol, m-ethylphenol, p-ethyl In addition to ethylphenols such as phenol, alkylphenols such as isopropylphenol, butylphenol and p-tert-butylphenol, polyhydric phenols such as resorcin, catechol, hydroquinone, pyrogallol and phloroglucin, alkylresorcin, Alkyl polyhydric phenols (all alkyl groups have 1 to 4 carbon atoms), such as alkyl catechol and alkyl hydroquinone, are mentioned. These can be used individually or in combination of 2 or more types.

Among the phenols, it is particularly preferable to use m-cresol and p-cresol. By using these phenols, and adjusting the compounding ratio of both, various characteristics, such as a sensitivity as photoresist and heat resistance, can be adjusted. In this case, although the ratio of m-cresol and p-cresol is not specifically limited, It is preferable to set it as weight ratio (m-cresol / p-cresol) = 9/1-1/9. More preferably, they are 8/2-2/8. When the ratio of m-cresol becomes less than the said lower limit, sensitivity may fall, and when it exceeds the said upper limit, heat resistance may fall.

Although it does not specifically limit as aldehydes used in the said reaction, For example, formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxymethylene, chloral, hexamethylenetetramine, furfural, glyoxal , n-butylaldehyde, caproaldehyde, allylaldehyde, benzaldehyde, crotonaldehyde, acrolein, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde and the like. Among these, it is preferable in view of the use of formaldehyde and paraformaldehyde.

The reaction molar ratio (F / P) of the phenols (P) and aldehydes (F) is not particularly limited, and one embodiment of the present invention is carried out at a known reaction molar ratio in the production of novolak-type phenol resins. Can be.

In particular, when applying the obtained novolak-type phenol resin for photoresists, it is preferable to make reaction molar ratio into 0.5-1.0. Thereby, the resin composition which has a molecular weight suitable for a photoresist is obtained. When the said reaction molar ratio exceeds the said upper limit, the resin composition may become excessively high molecular weight, or may gelatinize depending on reaction conditions in order to use for photoresist. Moreover, below the said lower limit, since content of the low nucleus component becomes relatively large, the efficiency at the time of removing this may fall.

An acid catalyst is generally used for reaction of the said phenols and aldehydes. Although it does not specifically limit as an acid catalyst, For example, organic carboxylic acids, such as oxalic acid and acetic acid, etc. are mentioned. Among these, you may use 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 the said phenols. When the resin for photoresist is used in the photoresist composition, it is preferable that the amount of catalyst remaining in the resin is small in order to prevent interference with the properties of the photoresist. Of course, in the process of synthesizing the resin, the catalyst may be removed by a general removal method (neutralization, water washing or filter filtration).

Moreover, as a reaction solvent used for manufacturing the resin composition for photoresists of this invention, a moderately nonpolar solvent is preferable, For example, hexane, benzene, xylene, etc. are mentioned.

As a phenol resin used for manufacturing the resin composition for photoresists of this invention, the phenol resin whose weight average molecular weight measured by GPC (Gel Permeation Chromatography) is 1000-20000 Dalton is preferable, More preferable weight average molecular weights are 3000- 10000 daltons. By making the weight average molecular weight of the phenol resin to be in the said range, the sensitivity, heat resistance, and residual film ratio of the resin composition for photoresists can be made optimal.

The said weight average molecular weight is computed based on the analytical curve created using the polystyrene standard substance. GPC measurement can be performed using tetrahydrofuran as an elution solvent, using a differential refractometer as a detector on conditions of flow rate 1.0 ml / min and column temperature 40 degreeC. Devices that can be used are, for example,

1) Main body: `` HLC-8020 '' manufactured by TOSOH

2) Detector: manufactured by TOSOH Co., Ltd., set at a wavelength of 280 nm, "UV-8011"

3) Column for analysis: SHOWEX KF-802, KF-803, KF-805 can be used.

The cyclic olefin resin used to manufacture the resin composition for photoresists of the present invention is a resin having a cyclic olefin structure in its main chain, and a rigid structure in which the cyclic structure derived from the cyclic olefin is directly connected in the chain length direction of the polymer. Since it has a structure, it has a high glass transition point. Among these resins, norbornene resins are preferred in view of the performance of the resulting photoresist composition. As a structure of norbornene resin, what is represented by General formula (1) is mentioned, for example. As a functional group on norbornene resin, it selects suitably according to the purpose of use of the photoresist composition obtained, and can be used without a restriction | limiting in particular.

[Formula 2]

Of the expression (1), X is _{O, CH 2, CH 2 CH} 2 It is either, n is an integer of 0-5. R ¹ to R ⁴ Is independently selected from the C1-C30 monovalent organic group or hydrogen which may contain O and / or F in the structure, respectively. R ¹ to R ⁴ It is or different from the repetition of a monomer, but the total repeating units of the R ¹ ~ R ^4, at least one is one having an acid group.

As an acidic group which gives alkali solubility to resin, a carboxyl group, a phenol group, a fluoro alcohol group, a sulfoamide group, etc. are mentioned, One or two or more of these can be introduce | transduced. Among these, the phenol group which can anticipate high contrast and high residual film rate by interaction with a photosensitizer is especially preferable.

Generally, as an example of the synthesis | combining method of these resin, what superposes | polymerizes the cyclic olefin represented by General formula (2) as a monomer.

(3)

Wherein, in formula (2), X is O, CH ₂ , CH ₂ CH ₂ It is either, n is an integer of 0-5. R ¹ to R ⁴ Is independently selected from the C1-C30 monovalent organic group or hydrogen which may contain O and / or F in the structure, respectively. R ¹ to R ⁴ It is or different from the repetition of a monomer, but the total repeating units of the R ¹ ~ R ^4, at least one is one having an acid group. As an acidic group, a carboxyl group, a phenol group, a fluoro alcohol group, and a sulfoamide group can be mentioned, One or two or more of these can be introduced.

Specific examples of the cyclic olefin monomer used in the present invention include, for example, bicyclo [2.2.1] hept-2-ene-5-carboxylic acid and tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] Dodec-3-ene-8-carboxylic acid, 8-methyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] dodec-3-ene-8-carboxylic acid, (bicyclo [2.2 .1] hept-2-en-5-yl) acetic acid, 2- (bicyclo [2.2.1] hept-2-en-5-yl) propionic acid, 3- (bicyclo [2.2.1] hept-2 -En-5-yl) butyric acid, 3- (bicyclo [2.2.1] hept-2-en-5-yl) valeric acid, 3- (bicyclo [2.2.1] hept-2-ene-5- I) caproic acid, mono-succinate mono- (2- (bicyclo [2.2.1] hept-2-en-5-yl) carbonyloxyethyl) ester, monosuccinate mono- (2- (bicyclo [2.2.1] Hept-2-en-5-yl) carbonyloxypropyl) ester, mono succinate mono- (2- (bicyclo [2.2.1] hept-2-en-5-yl) carbonyloxybutyl) ester, mono phthalate -(2- (bicyclo [2.2.1] hept-2-en-5-yl) carbonyloxyethyl) ester, caproic acid mono- (2- (ratio Cyclo [2.2.1] hept-2-en-5-yl) carbonyloxybutyl) ester, (bicyclo [2.2.1] hept-2-en-5-yl) carbonyloxyacetic acid, 2- (ratio Cyclo [2.2.1] hept-2-en-5-yl) methylphenol, 3- (bicyclo [2.2.1] hept-2-en-5-yl) methylphenol, 4- (bicyclo [2.2. 1] hept-2-en-5-yl) methylphenol, 4- (bicyclo [2.2.1] hept-2-en-5-yl) phenol, 4- (bicyclo [2.2.1] hept-2 -En-5-yl) methylcatechol, 3-methoxy-4- (bicyclo [2.2.1] hept-2-en-5-yl) methylphenol, 3-methoxy-2- (bicyclo [ 2.2.1] hept-2-en-5-yl) methylphenol, 2- (bicyclo [2.2.1] hept-2-en-5-yl) methylresorcin, 1,1-bistrifluoromethyl -2- (bicyclo [2.2.1] hept-2-en-5-yl) ethyl alcohol, 1,1-bistrifluoromethyl-3- (bicyclo [2.2.1] hept-2-ene- 5-yl) propyl alcohol, 1,1-bistrifluoromethyl-4- (bicyclo [2.2.1] hept-2-en-5-yl) butyl alcohol, 1,1-bistrifluoromethyl- 5- (bicyclo [2.2.1] hept-2-en-5-yl) pentyl alcohol, 1,1-bite Although lifluoromethyl-6- (bicyclo [2.2.1] hept-2-en-5-yl) hexyl alcohol etc. are mentioned, It is not limited to these structures.

Alternatively, after the same polymerization is carried out using a cyclic olefin monomer having no acidic group instead of the cyclic olefin monomer represented by the general formula (2), it can also be obtained by introducing an acidic group into the residue in a polymer reaction. Or by using the monomer which substituted the ionizable hydrogen atom of the acidic group in the cyclic olefin monomer represented by General formula (2) by another structure, after addition-polymerizing this, deprotection and introducing an original hydrogen atom You can also get Restoration of acidic groups by deprotection can be carried out by a conventional method.

The acid group equivalent of the cyclic olefin resin having an acid group in the side chain, which is used in the production of the resin composition for photoresists of the present invention, is not particularly limited here, because it also varies depending on its molecular structure, but it is 600 g / mol or less, Moreover, it is preferable that it is 400 g / mol or less. It is soluble in aqueous solutions of inorganic alkalis such as sodium hydroxide, potassium hydroxide, aqueous ammonia and the like, organic alkalis such as tetramethylammonium hydroxide, ethylamine, triethylamine, and triethanolamine, which are used at the time of the acidic group equivalent or less. do. When an acidic group equivalent is larger than the said upper limit, the solubility with respect to the said aqueous alkali solution becomes difficult to express, and it becomes difficult to perform pattern processing. The amount of acidic groups in the resin can be measured by titration of a resin solution using a standard alkali solution.

The acidic group equivalent of resin obtained can be controlled by selection of the molecular structure of the monomer which has an acidic group to be used, or copolymerization by changing the abundance ratio of the monomer which does not have a monomer which has an acidic group, etc.

As a method of manufacturing cyclic olefin resin, the conventionally well-known method is applicable. For example, addition polymerization can be carried out using a nickel compound or a palladium compound which is a coordination polymerization catalyst. Examples of the nickel compound include a catalyst represented by the chemical formula: E _n Ni (C ₆ F ₅ ) ₂ , in which n is 1 or 2, and E represents a neutral ligand. When n is 1, E is preferably a π-arene ligand such as toluene, benzene, and mesitylene. When n is 2, E is preferably selected from diethyl ether, THF (tetrahydrofuran), ethyl acetate, and dioxane. For example, (toluene) bis (perfluorophenyl) nickel, (mesitylene) bis (perfluorophenyl) nickel, (benzene) bis (perfluorophenyl) nickel, bis (tetrahydrofuran) bis (perfluoro Rophenyl) nickel, bis (ethyl acetate) bis (perfluorophenyl) nickel, bis (dioxane) bis (perfluorophenyl) nickel and the like. The details are described in PCT WO 97/33198, PCT WO 00/20472, Japanese Patent Application Laid-Open No. 2010-523766, Japanese Patent Application Laid-open No. Hei 11-505880, and the like.

Preferred polymerization solvents used for these polymerizations include hydrocarbons and aromatic solvents. Examples of the hydrocarbon solvent include, but are not limited to, pentane, hexane, heptane and the like. Moreover, although an example of an aromatic solvent is toluene, xylene, mesitylene, etc., it is not limited to these too. In addition, tetrahydrofuran, diethyl ether, ethyl acetate, lactone, ketone and the like can also be used. These solvent can be used individually by 1 type, and what mixed two or more types can be used as a polymerization solvent.

About the superposition | polymerization of the monomer contained in the resin composition for photoresists of this invention, the molecular weight of resin obtained by superposition | polymerization changes the ratio of a catalyst and a monomer, for example, is controlled also by superposition | polymerization temperature, polarity of a polymerization solvent, etc. It is possible. Moreover, the molecular weight of resin obtained by superposition | polymerization can also be controlled by addition of a chain transfer agent suitably.

The weight average molecular weight of cyclic olefin resin used for manufacture of the resin composition for photoresists of this invention is 1000-500,000 Daltons. When a weight average molecular weight exceeds the said range, the solubility with respect to the aqueous alkali solution of a resin composition falls at the time of the light processing, and there exists a possibility that favorable light workability may not be obtained. On the other hand, when a weight average molecular weight is less than the said minimum, there exists a possibility that the performance improvement effect by addition may not fully be acquired.

As a compounding quantity of cyclic olefin resin with respect to a phenol resin, 1-90 weight% is preferable, More preferably, it is 5-50 weight%. Although the addition amount can be arbitrarily set according to the degree of desired heat resistance improvement effect, when there is too much addition amount, there exists a possibility that the property, such as the sensitivity which a phenol resin has, may fall. On the other hand, when there is too little addition amount, the improvement effect of heat resistance may be inadequate.

The photosensitizer used for manufacture of the photoresist composition of this invention is a naphthoquinone diazide group containing compound. As a naphthoquinone diazide group containing compound, for example,

(1) 2,3,4-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,6-trihydroxybenzo Phenone, 2,3,4-trihydroxy-2'-methylbenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,3 ', 4,4', 6-pentahydroxybenzophenone, 2,2 ', 3,4,4'-pentahydroxybenzophenone, 2,2', 3,4,5-pentahydroxy Polyhydroxybenzoates such as benzophenone, 2,3 ', 4,4', 5 ', 6-hexahydroxybenzophenone, and 2,3,3', 4,4 ', 5'-hexahydroxybenzophenone Penon,

(2) bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4'-hydroxyphenyl Propane, 2- (2,4-dihydroxyphenyl) -2- (2 ', 4'-dihydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- ( 2 ', 3', 4'-trihydroxyphenyl) propane, 4,4'-X1- [4- [2- (4-hydroxyphenyl) -2-propyl] phenyl] ethylidene bisphenol, 3 Bis [(poly) hydroxyphenyl] alkanes such as 3'-dimethyl-X1- [4- [2- (3-methyl-4-hydroxyphenyl) -2-propyl] phenyl] ethylidene bisphenol ,

(3) tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl)- 4-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2, 5-dimethylphenyl) -2-hydroxyphenylmethane , Bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane Tris (hydroxyphenyl) methanes such as methyl substituents thereof,

(4) bis (3-cyclohexyl-4-hydroxyphenyl) -3-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -2-hydroxyphenylmethane, bis (3-cyclo Hexyl-4-hydroxyphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy Hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl ) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl)- 3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -4-hydroxyphenyl Methane, bis (3-cyclohexyl-2-hydroxyphenyl) -2 -Hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -4-hydroxy Bis (cyclohexyl hydroxyphenyl) (hydroxyphenyl) methane, such as oxyphenyl methane, its methyl substituent, etc.,

Fully ester compounds, partial ester compounds, amidates with quinonediazide group-containing sulfonic acids such as naphthoquinone-1,2-diazide-5-sulfonic acid or naphthoquinone-1,2-diazide-4-sulfonic acid; Partial amide cargo etc. are mentioned.

Here, as said naphthoquinone diazide group containing compound component, you may contain individually by 1 type, and may contain 2 or more types.

Although it does not specifically limit as a compounding quantity of the photosensitive agent in the resin composition of this invention, It can mix | blend in the range of 5-100 weight part normally, Preferably it is 10-50 weight part with respect to 100 weight part of phenol resins. If the compounding quantity of a photosensitizer is less than the said lower limit, the image faithful to a pattern will be hard to be obtained, and transferability may fall. On the other hand, when the said upper limit is exceeded, the fall of a sensitivity may be seen as a photoresist.

The solvent mix | blended with the composition of this invention will not be specifically limited if the said phenol resin, cyclic olefin resin, and a naphthoquinone diazide group containing compound melt | dissolve. In the present invention, these components are dissolved in a solvent and used. As a solvent used for manufacture of the photoresist composition of this invention, N-methyl- 2-pyrrolidone, (gamma) -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-methoxypropionate, etc. can be used individually or in mixture.

In addition to the components described above, various additives such as stabilizers such as antioxidants, plasticizers, surfactants, adhesion promoters, and dissolution accelerators may be used for the composition of the present invention.

Although it does not specifically limit as a preparation method of the composition of this invention, When a filler and a pigment are not added to a composition, it only needs to mix and stir the said component by a conventional method, and when adding a filler and a pigment, For example, what is necessary is just to disperse | distribute and mix using dispersing apparatuses, such as a resolver, a homogenizer, and three roll mills. Moreover, you may filter using a mesh filter, a membrane filter, etc. further as needed.

By exposing through the mask to the composition of this invention obtained in this way, a structural change arises in a composition in an exposure part, and the solubility to alkaline developing solution can be promoted. On the other hand, in the non-exposed part, since the low solubility with respect to alkaline developing solution is maintained, resist function can be given by the difference in the solubility which arises in this way.

When the composition of the present invention is used as a photoresist, the naphthoquinone diazide group-containing compound in the composition causes a chemical change by irradiation with light, and is dissolved in an alkaline developer together with a novolak resin in a subsequent development step, and is not exposed. By generating a clear difference in dissolution rate between the parts, the target pattern can be obtained by development.

Hereinafter, the present invention will be described by synthesis examples and examples. However, the present invention is not limited to these synthesis examples and examples. In addition, "part" and "%" described in the synthesis example, the Example, and the comparative example all represent "weight part" and "weight%." However, the concentration (%) of the formalin aqueous solution is excluded.

Example

1. Synthesis of Phenolic Resin

(Synthesis Example 1)

600 g of m-cresols, 400 g of p-cresols, 527 g of 37% formalin, and 5 g of oxalic acid were charged into a 3-liter four-necked flask equipped with a stirring device, a thermometer, and a heat exchanger, and reacted under reflux for 4 hours. Thereafter, dehydration was carried out at atmospheric pressure to an internal temperature of 170 deg. C, followed by further dehydration and demonomerization at 200 deg. C under a reduced pressure of 9.3 × 10 ³ Pa to obtain 950 g of a phenol resin having a weight average molecular weight of 4200 Daltons.

2. Synthesis of Cyclic Olefin Resin

(Synthesis Example 2)

Reaction of [4- (2-bicyclo [2.2.1] hepta-5-ene) phenyl] acetate (11.4 g, 50 mmol), toluene (17.6 g) and methylethylketone (27.4 g) with a stirring device It injected into the container and replaced the inside with dry nitrogen gas. Heating the contents, at the time when the internal temperature reached 50 ℃ (η ⁶ - _{toluene) Ni (C 6 F 5)} 2 was added to a solution dissolving a (0.97 g, 2.00 mmol) in toluene of 10 g. After reacting at 50 degreeC for 3 hours, it cooled to room temperature. THF (50 g) and 10% aqueous potassium hydroxide solution (80 g) were added, and the mixture was refluxed for 5 hours. Thereafter, acetic acid was added and neutralized, followed by washing with water three times with ion-exchanged water. The organic layer was concentrated with an evaporator and then reprecipitated with hexane. The obtained solid was dried overnight with a 60 degreeC vacuum dryer, and 8.2g pale yellow powder was obtained. The molecular weight of the obtained polymer was Mw = 11,000 Mn = 5300 by GPC.

(Synthesis Example 3)

3-methoxy-4- (bicyclo [2.2.1] hept-2-en-5-yl) methylphenol, (5.0 g, 18.4 mmol), ethyl-3- (3-bicyclo [2.2.1] Hepta-5-ene) propanoate (0.89 g, 4.59 mmol) toluene (28 g) and methyl ethyl ketone (10 g) were injected into a reaction vessel equipped with a stirring device, and the interior was replaced with dry nitrogen gas. At the time of heating the contents of the internal temperature reached 60 ℃ - a (η ⁶ _{toluene) Ni (C 6 F 5)} 2 (0.22 g, 0.46 mmol) was added dissolved in 5 g of toluene. After reacting at 60 degreeC for 3 hours, it cooled to room temperature. THF (50 g) and 10% aqueous potassium hydroxide solution (50 g) were added, and the mixture was refluxed for 5 hours. Thereafter, acetic acid was added to neutralize, and then washed with ion-exchanged water three times. The organic layer was concentrated with an evaporator and then reprecipitated with hexane. The obtained solid was dried overnight with a 60 degreeC vacuum dryer, and 8.2g pale yellow powder was obtained. The molecular weight of the obtained polymer was Mw = 16,000 Mn = 9000 by GPC.

(Synthesis Example 4)

Ethyl-3- (3-bicyclo [2.2.1] hepta-5-ene) propanoate (37.3 g, 0.19 mol), 1,1-bistrifluoromethyl-2- (bicyclo [2.2.1 ] Hept-2-en-5-yl) ethyl alcohol (13.2 g, 0.05 mol), toluene (55 g), triethylsilane (1.4 g), ethyl acetate (13 g), dimethylanilinium tetrakis (pentafluor Rophenyl) borate (0.06 g, 0.07 mmol) was injected into a reaction vessel equipped with a stirring device, and the interior was replaced with dry nitrogen gas. When the contents were heated to reach an internal temperature of 100 ° C., (acetonitrile) bis (triisopropylphosphine) palladium (acetate) (pentafluorophenylborate) (0.03 g, 0.02 mmol) of ethyl acetate (6 g ) Solution was added. After reacting at 100 degreeC for 16 hours, it cooled to room temperature, THF and 10% potassium hydroxide aqueous solution (300g) were added, and it was made to reflux for 5 hours. Thereafter, acetic acid was added to neutralize, and then washed with ion-exchanged water three times. The organic layer was concentrated with an evaporator and then reprecipitated with hexane. The obtained solid was dried overnight with a 60 degreeC vacuum dryer, and 27 g of white powder was obtained. The molecular weight of the obtained polymer was Mw = 8,200 Mn = 4,200 by GPC.

(Synthesis Example 5)

1,1-bistrifluoromethyl-2- (bicyclo [2.2.1] hept-2-en-5-yl) ethylalcohol (9.9 g, 0.036 mol), bicyclo [2.2.1] hept-2 -En-5-carboxylic acid trimethylsilyl ester (2.2 g, 0.012 mol), ethyl acetate (100 g), and cyclohexane (100 g) are injected into a reaction vessel equipped with a stirring device, and the inside is dried with dry nitrogen gas. Replaced. Methylene chloride (2 g) solution of (allyl) palladium (tricyclohexylphosphine) trifluoroacetate (0.006 g, 0.008 mmol) and lithium tetrakis (penta) when the contents were heated to reach an internal temperature of 100 ° C A solution of 0.034 g of toluene (2 g) of fluorophenyl) borate was added. 1-hexene (2.6 g, 0.03 mol) was further added, and it reacted at 20 degreeC for 5 hours, and then cooled to room temperature. The obtained polymer was thrown into methanol, the precipitate was aggregated, sufficiently washed with water, and then dried under vacuum to yield 7.8 g of white powder. The molecular weight of the obtained polymer was Mw = 12,200 Mn = 6,100 by GPC.

(Synthesis Example 6)

5-butylbicyclo [2.2.1] hept-2-ene (13.0 g, 0.087 mol), toluene (18 g) and methyl ethyl ketone (11 g) were injected into a reaction vessel equipped with a stirring device, and dried nitrogen The interior was replaced with gas. At the time of heating the contents of the internal temperature reached 60 ℃ (η ⁶ - _{toluene) Ni (C 6 F 5)} 2 was added to a solution dissolving a (0.42 g, 0.87 mmol) in toluene of 10 g. After reacting at 60 degreeC for 3 hours, it cooled to room temperature. The solution after the reaction was dissolved in 300 g of hexane, and washed with ion exchanged water three times. The organic layer was concentrated with an evaporator and then reprecipitated with methanol to give a white solid. The obtained solid was dried overnight with a 60 degreeC vacuum dryer, and 7.5 g of white powder was obtained. The molecular weight of the obtained polymer was Mw = 31,000 Mn = 14,000 by GPC.

4. Preparation of Photoresist Composition

(Example 1)

30 parts of novolac-type phenol resin obtained in Synthesis Example 1, 6 parts of cyclic olefin resin obtained in Synthesis Example 2, 2,3,4,4'-tetrahydroxybenzophenone and 6-diazo-5,6-di After dissolving 6 parts of ester of hydro-5-oxo-naphthalene-1-sulfonic acid in 150 parts of propylene glycol monomethyl ether acetate, it filtered using the membrane filter of 1.0 micrometer of pore diameters, and prepared the photoresist composition.

(Example 2)

30 parts of novolak-type phenol resins obtained in Synthesis Example 1, 15 parts of cyclic olefin resins obtained in Synthesis Example 2, 2,3,4,4'-tetrahydroxybenzophenone and 6-diazo-5,6-di After dissolving 6 parts of ester of hydro-5-oxo-naphthalene-1-sulfonic acid in 150 parts of propylene glycol monomethyl ether acetate, it filtered using the membrane filter of 1.0 micrometer of pore diameters, and prepared the photoresist composition.

(Example 3)

30 parts of novolak-type phenol resins obtained in Synthesis Example 1, 3 parts of cyclic olefin resins obtained in Synthesis Example 3, 2,3,4,4'-tetrahydroxybenzophenone and 6-diazo-5,6-di After dissolving 6 parts of ester of hydro-5-oxo-naphthalene-1-sulfonic acid in 150 parts of propylene glycol monomethyl ether acetate, it filtered using the membrane filter of 1.0 micrometer of pore diameters, and prepared the photoresist composition.

(Example 4)

30 parts of novolak-type phenol resins obtained in Synthesis Example 1, 6 parts of cyclic olefin resins obtained in Synthesis Example 4, 2,3,4,4'-tetrahydroxybenzophenone and 6-diazo-5,6-di After dissolving 6 parts of ester of hydro-5-oxo-naphthalene-1-sulfonic acid in 150 parts of propylene glycol monomethyl ether acetate, it filtered using the membrane filter of 1.0 micrometer of pore diameters, and prepared the photoresist composition.

(Example 5)

30 parts of novolak-type phenol resins obtained in Synthesis Example 1, 6 parts of cyclic olefin resins obtained in Synthesis Example 5, 2,3,4,4'-tetrahydroxybenzophenone and 6-diazo-5,6-di After dissolving 6 parts of ester of hydro-5-oxo-naphthalene-1-sulfonic acid in 150 parts of propylene glycol monomethyl ether acetate, it filtered using the membrane filter of 1.0 micrometer of pore diameters, and prepared the photoresist composition.

(Example 6)

30 parts of novolak-type phenol resins obtained in Synthesis Example 1, 3 parts of cyclic olefin resins obtained in Synthesis Example 6, 2,3,4,4'-tetrahydroxybenzophenone and 6-diazo-5,6-di After dissolving 6 parts of ester of hydro-5-oxo-naphthalene-1-sulfonic acid in 150 parts of propylene glycol monomethyl ether acetate, it filtered using the membrane filter of 1.0 micrometer of pore diameters, and prepared the photoresist composition.

(Comparative Example 1)

30 parts of novolac-type phenol resin obtained in Synthesis Example 1, 2,3,4,4'-tetrahydroxybenzophenone and 6-diazo-5,6-dihydro-5-oxo-naphthalene-1-sulfonic acid; 6 parts of esters were dissolved in 150 parts of propylene glycol monomethyl ether acetate, and then filtered using a membrane filter having a pore diameter of 1.0 µm to prepare a photoresist composition.

The characteristic evaluation shown below was performed using the photoresist composition obtained in Examples 1-5 and Comparative Examples 1-2. The results are shown in Table 1.

5. Evaluation method of characteristics

(1) Evaluation method of heat resistance

It applied on the hexamethyldisilazane treated silicon wafer so that the film thickness at the time of drying may be 1.5 micrometers with a spin coater, and it dried on the hotplate at 110 degreeC for 90 second. Then, it exposed through the test chart mask using the reduced-projection exposure apparatus, and developed for 60 second using the developing solution (2.38% tetramethylammonium hydroxide aqueous solution). The obtained silicon wafer was left to stand on the hotplate which changed temperature for 3 minutes, the shape of the resist pattern on a silicon wafer was observed with the scanning electron microscope, and the temperature at which it became impossible to obtain a normal resist pattern was made into heat resistant temperature.

(2) Residual film rate measuring method

The photoresist composition was applied on 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. The wafer was immersed in a developing solution (2.38% tetramethylammonium hydroxide aqueous solution) for 60 seconds, washed with water, and dried for 100 seconds on a 110 degreeC hotplate. The ratio of the film thickness after image development to the film thickness before image development was expressed as a percentage to set the residual film ratio. Thereby, the grade of the residual film (resistance) at the time of using it as a photosensitive agent and a photoresist can be known, and it shows that a residual film rate is high, so that a numerical value is high.

(3) measuring method of sensitivity

The photoresist composition was applied to a 3-inch silicon wafer with a spin coater to a thickness of about 1 μm and dried for 100 seconds on a 110 ° C. hot plate. Subsequently, a test chart mask was superimposed on this silicon wafer and irradiated with ultraviolet rays of 20 mJ / cm 2, 40 mJ / cm 2, and 60 mJ / cm 2, respectively, and developed for 90 seconds using a developing solution (2.38% tetramethylammonium hydroxide aqueous solution). The following references | standards evaluated the obtained pattern by observing a pattern shape with a scanning electron microscope.

A image can be formed at 20 mJ / cm 2 or less.

The image can be formed at B more than 20 mJ / cm 2 and 40 mJ / cm 2 or less.

It is possible to form an image at a C above 40 mJ / cm 2 and below 60 mJ / cm 2.

(4) measurement of resolution

The prepared photoresist composition was applied onto a silicon wafer using a spin coater and prebaked at 110 ° C. for 100 seconds to form a resist film having a thickness of 1.5 μm. It exposed using the ultraviolet-ray through the pattern mask which engraved the line width of 100-1 micrometer in this. Immediately after exposure, the solution was rapidly developed at 23 ° C. for 60 seconds with a 2.38 wt% aqueous tetramethylammonium hydrooxide solution, washed with water and dried to obtain a positive pattern. In that case, the dimension of the minimum photoresist pattern resolved by the fixed exposure amount was made into the resolution.

From the results of Table 1, Examples 1-5 are the resin composition for photoresists of this invention, and are those which have the outstanding residual film ratio, a sensitivity, and especially heat resistance compared with Comparative Examples 1-2 which are not the resin composition of this invention. Could prove that.

Industrial availability

Since the resin composition for photoresists of this invention has favorable thermal stability and has high residual film property with high sensitivity and high resolution, it can be used suitably for manufacture of the fine circuit of a liquid crystal display device circuit and a semiconductor integrated circuit.

Claims (11)

The resin composition for photoresists containing the novolak-type phenol resin, the cyclic olefin resin, and the photosensitizer which consists of a naphthoquinone diazide group containing compound. The method of claim 1,
The resin composition for photoresists, wherein the cyclic olefin resin is a norbornene resin. The method of claim 1,
The resin composition for photoresists whose said cyclic olefin resin is a cyclic olefin resin containing the repeating unit represented by following General formula (1).
[Formula 1]

Of the formula (1), X is _{O, CH 2, CH 2 CH} 2 It is either, n is an integer of 0-5. R ¹ to R ⁴ Is independently selected from the C1-C30 monovalent organic group or hydrogen which may contain O and / or F in the structure, respectively. R ¹ to R ⁴ Although it may differ in the repeat of a monomer, at least 1 has an acidic group among R <^1> -R <^4> of all the repeating units.] The method of claim 3, wherein
The resin composition for photoresists in which the said acidic group is 1 or more group chosen from the group which consists of a carboxyl group, a phenol group, a fluoro alcohol group, and a sulfoamide group. The method according to claim 3 or 4,
The resin composition for photoresists in which the said acidic group has a phenol group. The method according to any one of claims 1 to 4,
The photoresist resin composition whose weight average molecular weights of the said cyclic olefin resin are 1000-500,000 Daltons. The method of claim 5, wherein
The photoresist resin composition whose weight average molecular weights of the said cyclic olefin resin are 1000-500,000 Daltons. The method according to any one of claims 1 to 4,
The photoresist resin composition whose mixing ratio of the said cyclic olefin resin with respect to the said phenol resin is 1 to 90 weight%. The method of claim 5, wherein
The photoresist resin composition whose mixing ratio of the said cyclic olefin resin with respect to the said phenol resin is 1 to 90 weight%. The method according to claim 6,
The photoresist resin composition whose mixing ratio of the said cyclic olefin resin with respect to the said phenol resin is 1 to 90 weight%. The method of claim 7, wherein
The photoresist resin composition whose mixing ratio of the said cyclic olefin resin with respect to the said phenol resin is 1 to 90 weight%.