JP2014198755A - Novolac phenol resin and application of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novolac phenol resin with improved flexibility and applications of the resin, more particularly, a novolac phenol resin for a photoresist composition, which exhibits high flexibility as well as has high resolution and a high film-residual rate, and which is not only used for an epoxy resin composition and a cured product thereof but is suitably used for a lithographic processing in manufacturing a semiconductor or an LCD, and to provide a photoresist composition comprising the novolac phenol resin.SOLUTION: The novolac phenol resin is obtained by condensation polymerization of a phenol component (a) comprising bisphenol having a substituent at 2 and 2' positions, and a monoaldehyde component (b).

Description

  The present invention relates to a novolac type phenolic resin with improved flexibility and its use. In particular, in addition to its use as an epoxy resin composition and its cured product, it has high flexibility and high resolution and a high residual film ratio, which are suitably used in lithography processes when manufacturing semiconductors and LCDs. The present invention relates to a novolak type phenol resin for a photoresist composition and a photoresist composition containing the novolac type phenol resin.

  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 type photoresist having such a composition exhibits high resolving power when developed with an alkaline solution, and is used for the production of semiconductors such as IC and LSI, and circuit substrates such as LCDs. In addition, novolak-type phenolic resins have high heat resistance due to the structure having many aromatic rings against dry etching after exposure, and so far contain novolak-type phenolic resins and naphthoquinone diazide photosensitizers. Many positive photoresists have been developed and put into practical use.

  When this positive photoresist composition is used, a pattern having a fine line width of about 0.3 μm to a large line width of about several tens to several hundreds of μm can be formed on a wide variety of substrate surfaces. In the field of semiconductor manufacturing as well as in the field of LCD and the like, the line width of the pattern to be formed has been made finer with the progress of technology such as TFT and STN, and in recent high-definition TFT display elements, The design dimension of the line width is being demanded up to several μm level.

By the way, in the field of flexible printed wiring boards such as mobile phones, negative dry film photoresists are widely used. The resolution of the dry film photoresist is low, and the line width is about 30 to 300 μm.
On the other hand, the conventional positive photoresist composition has a high resolution as described above, but the film quality is brittle and lacks flexibility when trying to make a dry film. There were difficulties in handling. Therefore, a positive dry film photoresist has not been put into practical use.

  Therefore, Patent Document 1 shows high flexibility and enables high sensitivity and high resolution by polycondensation of methylphenols with dialdehydes containing at least one of glutaraldehyde and adipaldehyde. It has been proposed to obtain phenolic resins for photoresist compositions.

  Moreover, patent document 2 is related with a positive photosensitive resin laminated sheet and its manufacturing method. This document describes phenols and aldehydes constituting a novolak type phenol resin, and bisphenol A is exemplified as phenols and glutaraldehyde is exemplified as aldehydes together with many compounds.

International Publication No. 2010/050592 JP 2006-267660 A

However, although the novolac type phenol resin of Patent Document 1 is improved in flexibility, it cannot be said that it is sufficient for practical use as a flexible photoresist composition. There was room for improvement.
Patent Document 2 is intended to solve the brittleness of the film quality of the novolak-type phenol resin by means such as laminating a cushion layer, and examines the chemical composition of the novolac-type phenol resin, It does not improve the brittleness of the film quality. Therefore, the chemical composition of the novolac type phenol resin is not described in the examples.

  This invention is made | formed in view of the said problem, and it aims at proposing about the novolak-type phenol resin by which the softness | flexibility was improved, and its use. In particular, in addition to its use as an epoxy resin composition and its cured product, it has high flexibility and high resolution and a high residual film ratio, which are suitably used in lithography processes when manufacturing semiconductors and LCDs. It is to propose a novolak-type phenolic resin for a photoresist composition and a photoresist composition containing the novolak-type phenolic resin.

  As a result of intensive studies to achieve the above object, the present inventors have found that a novolak obtained by polycondensation reaction between a phenol component containing a bisphenol having a substituent at the 2,2′-position and a monoaldehyde component. It was found that type phenolic resin exhibits high flexibility by having a linear structure in the resin structure. In addition, the novolac type phenolic resin has high flexibility and high resolution and a high residual film ratio despite its low molecular weight, and therefore can be suitably used as a novolac type phenolic resin for a photoresist composition. Thus, the present invention has been achieved.

That is, the present invention relates to the following matters.
1. A novolak-type phenol resin obtained by polycondensation reaction of a phenol component (a) containing a bisphenol having a substituent at the 2,2′-position and a monoaldehyde component (b).

2. The novolak type phenol resin according to Item 1, wherein the bisphenol having a substituent at the 2,2′-position is represented by the following general formula (4).

（ここで、置換基Ｒ^１はそれぞれ独立に、炭素数が１〜６の直鎖のアルキル基、炭素数が１〜６の分岐を持つアルキル基、シクロヘキシル基、又はフェニル基である。また、Ｘは２価の基であって、アルキレン基、エーテル基、チオエーテル基、およびカルボニル基からなる群より選ばれる２価の基である。）

(Here, each substituent R ¹ is independently a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, or a phenyl group. X is a divalent group and is a divalent group selected from the group consisting of an alkylene group, an ether group, a thioether group, and a carbonyl group.

3. The molar ratio [(b) / (a)] of the phenol component (a) containing a bisphenol having a substituent at the 2,2′-position and the monoaldehyde component (b) is 0.45 or more. Item 3. A novolac type phenolic resin according to item 1 or 2.
4). Item 4. The novolak phenol resin according to any one of Items 1 to 3, wherein the molar ratio [(b) / (a)] is less than 0.45 to 1.5 and is used for a photoresist composition.
5. A novolac-type phenol resin represented by the following general formula (1).

（ここで、各Ａはそれぞれ独立に下記一般式（２）で表される１価又は２価の基からなり、各Ｂは下記一般式（３）で表される２価の基からなり、ｎは０〜１００の整数を表す。）

(Here, each A is independently composed of a monovalent or divalent group represented by the following general formula (2), each B is composed of a divalent group represented by the following general formula (3), n represents an integer of 0 to 100.)

（ここで、置換基Ｒ^１はそれぞれ独立に、炭素数が１〜６の直鎖のアルキル基、炭素数が１〜６の分岐を持つアルキル基、シクロヘキシル基、又はフェニル基である。また、Ｘは２価の基であって、それぞれ独立に、アルキレン基、エーテル基、チオエーテル基、およびカルボニル基からなる群より選ばれる２価の基である。）

(Here, each substituent R ¹ is independently a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, or a phenyl group. X is a divalent group, each independently a divalent group selected from the group consisting of an alkylene group, an ether group, a thioether group, and a carbonyl group.

（ここで、置換基Ｒ^２はそれぞれ独立に、水素基、炭素数が１〜６の直鎖のアルキル基、炭素数が１〜６の分岐を持つアルキル基、又は炭素数が５〜６の環状のアルキル基である。また、置換基Ｒ^３はそれぞれ独立に、水素基、水酸基、メチル基、又はメトキシ基であり、ｍは１〜３の整数である。）

(Here, each substituent R ² is independently a hydrogen group, a linear alkyl group having 1 to 6 carbon atoms, an alkyl group having a branch having 1 to 6 carbon atoms, or a group having 5 to 6 carbon atoms. The substituent R ³ is each independently a hydrogen group, a hydroxyl group, a methyl group, or a methoxy group, and m is an integer of 1 to ^3. )

6). 6. A photoresist composition comprising the novolak type phenolic resin according to item 4 or 5.
7). Item 6. An epoxy resin obtained by epoxidizing the novolak type phenol resin according to item 1, 2, 3 or 5.
8). The epoxy resin composition containing the epoxy resin of said claim | item 6.
9. 6. An epoxy resin composition comprising any one or more of the novolak type phenol resins according to the above items 1, 2, 3, and 5, and an epoxy resin.
10. The hardened | cured material which hardened the epoxy resin composition of the said claim | item 8 or 9.

  ADVANTAGE OF THE INVENTION According to this invention, it can propose about the novolak-type phenol resin by which the softness | flexibility was improved, and its use. In particular, in addition to its use as an epoxy resin composition and its cured product, it has high flexibility and high resolution and a high residual film ratio, which are suitably used in lithography processes when manufacturing semiconductors and LCDs. A novolak-type phenol resin for a photoresist composition and a photoresist composition containing the novolak-type phenol resin can be proposed.

  The present invention relates to a novolak type phenol resin obtained by polycondensation reaction between a phenol component (a) containing a bisphenol having a substituent at the 2,2′-position and a monoaldehyde component (b).

  In the present invention, the bisphenol having a substituent at the 2,2′-position means two hydroxyphenyl groups (structures) particularly by a divalent group exemplified by an alkylene group, an ether group, a thioether group, a carbonyl group and the like. ) Is a compound in which each 2-hydroxyphenyl group has a substituent on the phenolic hydroxyl group, and the other 2-position has no substituent. A compound in which the two hydroxyphenyl groups (structures) are bonded to each phenolic hydroxyl group at the 4-position by the divalent group is preferable.

  In the present invention, the bisphenol having a substituent at the 2,2′-position is not particularly limited, but is preferably represented by the following general formula (4).

In the compound represented by the general formula (4), two hydroxyphenyl groups having a substituent R ¹ at the 2-position (o-position) with respect to the phenolic hydroxyl group are each 4 with respect to the phenolic hydroxyl group. It is a bisphenol compound having a structure bonded by X which is a divalent group at the position (p-position).
Here, each of the substituents R ¹ is independently a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, or a phenyl group. X is a divalent group and is a divalent group selected from the group consisting of an alkylene group, an ether group, a thioether group, and a carbonyl group. A compound in which the two substituents R ¹ in the general formula (4) are the same is preferable.

  In the present invention, bisphenols having a substituent at the 2,2′-position are specifically bisphenol C; (2,2-bis (3-methyl-4-hydroxyphenyl) propane), 2,2- Bis (4-hydroxy-3-isopropylphenyl) propane, 2,2-bis (3-sec-butyl-4-hydroxyphenyl) propane, 2,2-bis (2-hydroxy-5-biphenylyl) propane, 2 , 2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, and bisphenol C represented by the following general formula (5) is preferable.

  Bisphenols having a substituent at the 2,2′-position may be used alone or as a mixture of two or more.

  In the present invention, the phenol component (a) is mainly composed of bisphenols having a substituent at the 2,2′-position. The proportion of bisphenols having a substituent at the 2,2 ′ position contained in the phenol component (a) is preferably 50 mol% or more, more preferably 60 mol%, assuming that the total amount of the phenol component (a) is 100 mol%. More preferably, it is 75 mol% or more, particularly preferably 95 mol% or more, and most preferably 100 mol%. By setting the ratio of the bisphenols having a substituent at the 2,2′-position contained in the phenol component (a) within the above range, the flexibility of the resulting novolak-type phenol resin is improved. When the proportion of bisphenols having a substituent at the 2,2′-position contained in phenols (a) decreases, the proportion of the linear structure in the resin decreases, and the flexibility of the resulting novolak phenol resin decreases. To do.

  The phenol component (a) of the present invention contains a bisphenol having a substituent at the 2,2 ′ position as an essential component, but other phenols can be used in combination as long as the effects of the present invention are not impaired. . Specific examples of other phenols include phenol, polyhydric phenol, m-cresol, p-cresol, o-cresol, xylenol, and trimethylphenol. As xylenol, structural isomers of 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, and 3,5-xylenol can be used. Structural isomers such as 2,3,5-trimethylphenol and 2,3,6-trimethylphenol can be used. Examples of the polyhydric phenol that can be used in the present invention include divalent phenols such as catechol, resorcin, hydroquinone, 3-methylcatechol, 4-methylcatechol, 2-methylresorcinol, 4-methylresorcinol, methylhydroquinone, 3 -Ethyl catechol, 4-ethyl catechol, 2-ethyl resorcinol, 4-ethyl resorcinol, ethyl hydroquinone, n-propyl hydroquinone, isopropyl hydroquinone, t-butyl hydroquinone, 4-n-hexyl resorcinol, 4-hexanoyl resorcinol, 3, 5-dimethylcatechol, 2,5-dimethylresorcinol, 2,3-diethylhydroquinone, 2,5-dimethylhydroquinone, 3,5-diethylcatechol, 2,5-di Tilresorcinol, 2,5-diethylhydroquinone, 3,5-diisopropylcatechol, 2,5-diisopropylresorcinol, 2,3-diisopropylhydroquinone, 2,5-diisopropylhydroquinone, 3,5-di-t-butylcatechol, 2, (Poly) alkyl-substituted dihydric phenols such as 2,5-di-t-butylresorcinol, 2,3-di-t-butylhydroquinone, 2,5-di-t-butylhydroquinone, and trivalent phenols, Examples include pyrogallol, phloroglucinol, 1,2,4-benzenetriol and the like. Of the polyphenols, particularly preferred is resorcin. These other phenols may be used alone or in admixture of two or more.

  In the present invention, the monoaldehyde component (b) is an aldehyde compound having only one aldehyde group in one molecule, and any of an aliphatic monoaldehyde, an alicyclic monoaldehyde, or an aromatic monoaldehyde is used. Can do.

  In the present invention, the monoaldehyde component (b) is not particularly limited, but is preferably represented by the following general formula (6).

Here, each substituent R ² is independently a hydrogen group, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 1 to 6 carbon atoms, or a cyclic group having 5 to 6 carbon atoms. It is an alkyl group. In addition, each of the substituents R ³ is independently a hydrogen group, a hydroxyl group, a methyl group, or a methoxy group, and m is an integer of 1 to 3.

  Examples of the aliphatic monoaldehyde include formaldehyde, trioxane, paraformaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, trimethylacetaldehyde, n-hexylaldehyde, acrolein, and crotonaldehyde. Examples of the alicyclic aldehyde include cyclopentane aldehyde, cyclohexane aldehyde, furfural, and furyl acrolein. Examples of aromatic aldehydes include benzaldehyde, o-tolualdehyde, m-tolualdehyde, p-tolualdehyde, p-ethylbenzaldehyde, 2,4-dimethylbenzaldehyde, 2,5-dimethylbenzaldehyde, 3,4-dimethylbenzaldehyde. 3,5-dimethylbenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-anisaldehyde, m-anisaldehyde, p- Anisaldehyde and the like can be mentioned. In particular, the aliphatic monoaldehyde formaldehyde, trioxane, or paraformaldehyde is preferable. These monoaldehyde compounds can be used individually by 1 type, or can also be used in combination of 2 or more type.

  In the novolac type phenol resin of the present invention, the molar ratio [(b) / (a)] of the phenol component (a) containing the bisphenol having a substituent at the 2,2′-position and the monoaldehyde component (b) Is preferably 0.45 or more, more preferably 0.5 to 1.4, still more preferably 0.6 to 1.3, particularly preferably 0.7 to 1.2, and most preferably 0.8 to 1. .1 is preferable because a novolac-type phenol resin having sufficiently improved flexibility can be obtained. In particular, when the novolak type phenolic resin of the present invention is used for a photoresist composition, by setting the molar ratio [(b) / (a)] to 0.45 or more and less than 1.5, high flexibility is achieved. In addition, a photoresist composition having high resolution and a high residual film ratio can be obtained. If the molar ratio [(b) / (a)] is less than 0.45, the flexibility of the photoresist composition cannot be sufficiently improved, the dissolution rate is increased, and the alkali dissolution is difficult to control, Since it becomes difficult to achieve high resolution and a high residual film ratio, it is not preferable. On the other hand, if it is 1.5 or more, it becomes insoluble in an alkaline solution and the sensitivity is lowered, so that there are cases where the photoresist composition is not practical.

  In the novolak-type phenol resin of the present invention, although not particularly limited, one of preferred embodiments is a phenol component (a) composed only of bisphenols represented by the general formula (4) and the general formula. It is a novolak type phenol resin represented by the following general formula (1) obtained by condensation polymerization reaction with the monoaldehyde component (b) represented by (6).

  Here, each A is composed of a monovalent or divalent group represented by the following general formula (2), each B is composed of a divalent group represented by the following general formula (3), and n is 0 to 0. An integer of 100 is represented.

Here, each of the substituents R ¹ is independently a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, or a phenyl group. X is a divalent group and is independently a divalent group selected from the group consisting of an alkylene group, an ether group, a thioether group, and a carbonyl group.

Here, each substituent R ² is independently a hydrogen group, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 1 to 6 carbon atoms, or a cyclic group having 5 to 6 carbon atoms. It is an alkyl group. In addition, each of the substituents R ³ is independently a hydrogen group, a hydroxyl group, a methyl group, or a methoxy group, and m is an integer of 1 to 3.

  The monovalent or divalent group represented by the general formula (2) is a structure of a novolak type phenol resin in which the bisphenol represented by the general formula (4) is represented by the general formula (1) by a condensation polymerization reaction. Is a monovalent or divalent group represented by the following general formula (7).

  In the divalent group represented by the general formula (3), the monoaldehyde component represented by the general formula (6) is incorporated into the structure of the novolak-type phenol resin represented by the general formula (1) by the condensation polymerization reaction. In this case, the reaction residue is more preferably a methylene group represented by the following general formula (8).

  N in the general formula (1) is the number of repeating units of the structure, and represents an integer of 0 to 100, preferably 0 to 70, more preferably 1 to 50, and still more preferably 1 to 35.

  The weight average molecular weight of the novolak type phenol resin of the present invention is not particularly limited. Usually, it is about 300-30000. When using for a photoresist composition, 700-20000 are preferable, 800-15000 are more preferable, and 1000-10000 are still more preferable from the performance and handling property of a photoresist composition. When the weight average molecular weight is less than 300, the sensitivity may be too high, and when it is greater than 30000, the sensitivity may be low. In addition, in this specification, a weight average molecular weight is the value calculated | required using the analytical curve by a standard polystyrene by GPC (gel permeation chromatography) measurement.

  The novolak-type phenol resin of the present invention can be easily obtained by polycondensation reaction of a phenol component (a) containing a bisphenol having a substituent at the 2,2′-position and a monoaldehyde component (b). it can.

  In the condensation polymerization reaction, an acid catalyst can be preferably used. Any acid catalyst can be used without particular limitation as long as it has the ability to react a phenol component with an aldehyde component. For example, organic sulfonic acids such as oxalic acid, benzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, and inorganic acids such as hydrochloric acid and sulfuric acid can be used. The usage-amount of an acid catalyst is 0.01-5 weight% with respect to phenols (a) containing bisphenol. When used for a photoresist composition, it is preferable that the amount is as small as possible in order to improve its properties. This is because the acid catalyst remaining in the resin may adversely affect the characteristics of the photoresist composition. For this reason, after completion of the condensation polymerization reaction, it is preferable to neutralize the acid catalyst in the reaction mixture using an amine or an inorganic alkali.

  The reaction temperature of the condensation polymerization reaction is not particularly limited, but is preferably 60 to 160 ° C, more preferably 80 to 140 ° C. When the temperature is lower than 60 ° C., the polymerization is difficult to proceed, and when the temperature is higher than 160 ° C., it may be difficult to control the reaction, and it becomes difficult to stably obtain the desired novolak type phenol resin.

  In the condensation polymerization reaction, a reaction solvent can be used as necessary. As the reaction solvent, water that easily dissolves the phenol component (a) and the monoaldehyde component (b) containing bisphenols having a substituent at the 2,2′-position is preferably used. It is also possible to use an organic solvent that does not affect. Examples of such organic solvents include ethers such as diethylene glycol dimethyl ether, 1,2-dimethoxyethane, and 1,2-diethoxyethane; esters such as propylene glycol monomethyl ether acetate; and cyclic ethers such as tetrahydrofuran and dioxane. Can be mentioned. The usage-amount of these reaction solvents is a ratio of 20-1000 mass parts normally with respect to 100 mass parts of reaction raw materials.

  The reaction time of the condensation polymerization reaction is usually within 20 hours, although it depends on the reaction temperature. The reaction pressure for the polycondensation reaction is usually carried out under normal pressure, but can also be carried out under slight pressure or reduced pressure.

  In the post-treatment after completion of the polycondensation reaction, it is preferable to add a base to the reaction mixture to neutralize the acid catalyst, and then add water to remove the acid catalyst and perform washing with water.

  The base for neutralizing the acid catalyst is not particularly limited, and any base that neutralizes the acid catalyst and forms a salt that is soluble in water can be used. Examples of the base include inorganic bases such as metal hydroxides and metal carbonates, and organic bases such as amines and organic amines. Specific examples of the inorganic base include sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium bicarbonate, and calcium carbonate. Specific examples of organic base amines or organic amines include ammonia, trimethylamine, triethylamine, diethylamine, and tributylamine. Preferably organic amines are used. It is preferable to use the base in such an amount that the acid catalyst is neutralized and the pH in the reaction system is in the range of 4-8.

The amount of washing water and the number of washings are not particularly limited. In order to remove the acid catalyst to an amount that does not affect the actual use as a resist composition, the number of washings is about 1 to 5 times.
The temperature of washing with water is not particularly limited, but it is preferably 40 to 95 ° C. from the viewpoint of catalyst removal efficiency and workability. When the resin and the washing water are poorly separated during washing with water, it is effective to add a solvent that lowers the viscosity of the resin and raise the washing temperature. Such a solvent can be used without particular limitation as long as it dissolves the phenol resin and lowers the viscosity.

  After removing the acidic catalyst by neutralization and washing with water, for example, the temperature of the reaction system is raised to 130 to 230 ° C., and the volatilization of unreacted raw materials, organic solvents, etc. present in the reaction system under a reduced pressure of 20 to 50 torr. The novolak type phenolic resin of the present invention can be obtained by distilling off the fraction.

  The novolac type phenolic resin of the present invention can be used in various fields in the same manner as a normal novolac type phenolic resin.

  For example, the novolac type phenol resin of the present invention can be used as a curing agent for epoxy resins. When used as a curing agent for an epoxy resin, it can be mixed with an epoxy resin according to a known method to obtain an epoxy resin composition.

  Moreover, the novolak-type phenol resin of this invention can also be made into a novolak-type epoxy resin (henceforth a novolak-type epoxy resin) by making it react with epihalohydrin by a well-known method. For example, a novolac type epoxy resin can be obtained by performing a glycidyl etherification reaction at 10 to 120 ° C. in the presence of epichlorohydrin and an alkali metal hydroxide such as sodium hydroxide.

  The novolac type epoxy resin obtained by epoxidizing the novolak type phenol resin of the present invention is, for example, an amine-based curing agent, an amide-based curing agent, a dianhydride-based curing agent, or a novolac-type phenolic resin-based curing agent according to a known method. It can mix and can be set as an epoxy resin composition.

  The epoxy resin composition of the present invention includes a curing accelerator such as triphenylphosphine, and further includes an inorganic filler, a release agent, a colorant, a coupling agent, and a flame retardant, as long as the effects of the present invention are not impaired. The additive which a normal epoxy resin composition contains, such as can be contained suitably.

  The epoxy resin composition of the present invention can form a cured product by causing a curing reaction by heat treatment. Conditions for curing the epoxy resin composition of the present invention can be appropriately selected. For example, a cured product can be obtained by heat treatment at 50 to 300 ° C., preferably 130 to 250 ° C., for 0.01 to 20 hours, preferably 0.1 to 10 hours.

  The cured product of the epoxy resin composition of the present invention can be suitably applied in the field of semiconductors and electronic components as printed wiring board materials, interlayer insulating materials for build-up boards, semiconductor sealing materials, conductive adhesive materials, and the like. it can.

  The novolak-type phenolic resin of the present invention can be suitably used for a photoresist composition that exhibits particularly high flexibility and has both high resolution and a high residual film ratio.

  The photoresist composition of the present invention contains, but is not limited to, the novolac type phenol resin (A) of the present invention, preferably 5 to 40% by weight, more preferably 10 to 25% by weight. The resist composition of the present invention further contains a photosensitive agent (B). As the photosensitizer (B), known photosensitizers for photoresists containing novolak-type phenolic resins can be used. For example, a quinonediazide compound having a quinonediazide group is preferable, and a 1,2-quinonediazide compound or a derivative thereof is particularly preferable. By using a quinonediazide compound, the exposed portion has a higher alkali dissolution rate due to the dissolution promoting effect, and conversely, the non-exposed portion has a lower alkali dissolution rate due to the dissolution inhibiting effect. Due to the difference, a sharp resist pattern with high contrast can be obtained.

  As the quinonediazide compound, known compounds conventionally used in quinonediazide-novolak photoresist compositions can be used. Examples of the compound containing a quinonediazide group include compounds obtained by reacting naphthoquinonediazidesulfonic acid chloride, benzoquinonediazidesulfonic acid chloride, and the like with a compound having a functional group capable of undergoing a condensation reaction with these acid chlorides. preferable.

  Here, examples of the functional group capable of condensing with acid chloride include a hydroxyl group and an amino group, and a hydroxyl group is particularly preferable. Examples of the compound having a hydroxyl group capable of condensing with acid chloride include hydroquinone, resorcin, 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,4,4 '-Trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,2 ', 3,4,6'-pentahydroxybenzophenone, etc. Hydroxyphenyl alkanes such as hydroxybenzophenones, bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) propane, 4,4 ′ , 3 ", 4" -tetrahydroxy-3,5,3 ', Hydroxytriphenylmethanes such as' -tetramethyltriphenylmethane, 4,4 ', 2 ", 3", 4 "-pentahydroxy-3,5,3', 5'-tetramethyltriphenylmethane These may be used alone or in combination of two or more.

  Specific examples of naphthoquinone diazide sulfonic acid chloride and benzoquinone diazide sulfonic acid chloride that are acid chlorides include, for example, 1,2-naphthoquinone diazide-5-sulfonyl chloride, 1,2-naphthoquinone diazide-4-sulfonyl chloride, and the like. As mentioned.

  The blending amount of the photosensitive agent (B) is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass with respect to 100 parts by mass of the novolac type phenol resin (A). When the blending amount of the photosensitizer (B) is less than 5 parts by mass, sufficient sensitivity as a photosensitive tree composition may not be obtained, and when it exceeds 50 parts by mass, a problem of precipitation of components occurs. This is not preferable.

  The resist composition of the present invention includes, in addition to the novolak-type phenolic resin (A) and the photosensitive agent (B), stabilizers such as antioxidants, plasticizers, surfactants, which are conventional components of photoresist compositions, An adhesion improver, a dissolution accelerator, a dissolution inhibitor and the like can be suitably contained.

  The photoresist composition using the novolac-type phenolic resin of the present invention can be formed into a dry film, and is a lithography process for manufacturing a highly integrated semiconductor, a thin film transistor (TFT) for liquid crystal, a flexible display, and a flexible display. It can be suitably used in a microfabrication process such as a printed wiring board.

  Hereinafter, the present invention will be described more specifically with reference to examples and the like, but the present invention is not limited to these examples.

  First, a method for analyzing a novolac-type phenol resin and a method for evaluating its physical properties are as follows.

≪ (1) Weight average molecular weight (GPC measurement method) ≫
Model: HLC-8220 Tosoh Corporation Column: TSK-GEL H type G2000H × L 4
1 G3000H x L
G4000H × L One measurement condition: Column pressure 13.5 MPa
Eluent: Tetrahydrofuran (THF) flow rate 1 ml / min
Temperature: 40 ° C
Detector: Spectrophotometer (UV-8020) RANGE 2.56
WAVE LENGTH: 254nm and RI
Injection volume: 100 μmL
Sample concentration: 5 mg / mL

≪ (2) Evaluation method of alkali dissolution rate of novolac type phenol resin≫
3 g of novolak type phenol resin was dissolved in 9 g of PGMEA (propylene glycol monomethyl ether acetate) to prepare a resin solution. These were filtered through a 0.2 micron membrane filter. This was coated on a 4 inch silicon wafer with a spin coater to a thickness of about 1.5 μm, and dried on a hot plate at 110 ° C. for 60 seconds. Next, using a developing solution (1.60% tetramethylammonium hydroxide aqueous solution), the time until the film completely disappeared was measured. The value obtained by dividing the initial film thickness by the time until dissolution was taken as the dissolution rate.

  Next, a method for preparing a photoresist composition (photosensitive composition), and a method for evaluating the photosensitizer solubility, coatability, flexibility, residual film ratio (%), and resolution of the obtained composition are as follows. It is.

≪ (3) Preparation of photoresist composition≫
107.5 g of the obtained novolak-type phenol resin and 2.5 g of 2,3,4,4′-tetrahydroxybenzophenone ester of naphthoquinone 1,2-diazide-5-sulfonic acid were added to 37.5 g of PGMEA (propylene glycol monomethyl ether acetate). To give a photoresist composition.

≪ (4) Photoresist composition flexibility evaluation≫
The obtained novolac-type phenol resin was dissolved in PGMEA (propylene glycol monomethyl ether acetate) to prepare a resin solution. These were filtered through a 0.2 micron membrane filter. This was applied on a polyimide film having a thickness of 50 μm so as to have a thickness of about 5.0 μm, and dried on a hot plate at 110 ° C. for 90 seconds.
After drying, the state of the resist surface was observed, and the applicability was evaluated based on the presence or absence of cissing.
Subsequently, it was immersed for 60 seconds using the developing solution (2.38% tetramethylammonium hydroxide aqueous solution). After rinsing and drying, bending was performed at 180 degrees, and the state of the bent portion was observed and evaluated visually and under a microscope (1000 times) according to the following criteria.
○: There is no crack in the resist film by microscopic observation. Δ: There is no crack in the resist film by visual observation, but there is crack in the resist film by microscopic observation (it is difficult to put it into practical use as a flexible photoresist composition. )
X: There is a crack in the resist film by visual observation.

≪ (5) Evaluation method of remaining film ratio and resolution of photoresist composition≫
The photoresist composition is filtered through a 0.2 micron membrane filter, which is coated on a 4 inch silicon wafer with a spin coater to a thickness of about 1.5 μm, and dried on a hot plate at 110 ° C. for 60 seconds. I let you. Thereafter, exposure was performed using a reduced projection exposure apparatus while changing the exposure time stepwise. Next, using a developer (2.38% tetramethylammonium hydroxide aqueous solution), development was performed for 60 seconds, followed by rinsing and drying.
The remaining film ratio is a ratio between the film thickness of the photosensitive resin after development and the film thickness of the photosensitive resin before development, and is a value represented by the following formula.

The resolution was evaluated according to the following criteria using a test chart mask.
○: 4.0 μ line & space can be resolved.
X: 4.0 μ line & space cannot be resolved.

[Example 1]
A glass three-necked flask equipped with a thermometer, a charging / distilling outlet and a stirrer was charged with 30 g (0.117 mol) of bisphenol C, 5.79 g (0.082 mol) of 42% formaldehyde aqueous solution, and 0.11 g of oxalic acid. The reaction was carried out at 20 ° C. for 20 hours. Thereafter, the temperature was raised to 180 ° C. for dehydration, followed by distillation under reduced pressure at 30 torr for 2 hours to obtain 32 g of a novolac type phenol resin.

[Example 2]
A glass three-necked flask equipped with a thermometer, a charging / distilling outlet and a stirrer was charged with 30 g (0.117 mol) of bisphenol C, 6.62 g (0.094 mol) of a 42% formaldehyde aqueous solution, and 0.11 g of oxalic acid. The reaction was carried out at 20 ° C. for 20 hours. Thereafter, the temperature was raised to 180 ° C. for dehydration, followed by distillation under reduced pressure at 30 torr for 2 hours to obtain 35 g of a novolac type phenol resin.

Example 3
A glass three-necked flask equipped with a thermometer, a charging / distilling outlet and a stirrer was charged with 30 g (0.117 mol) of bisphenol C, 8.28 g (0.117 mol) of a 42% formaldehyde aqueous solution, and 0.11 g of oxalic acid. The reaction was carried out at 20 ° C. for 20 hours. Thereafter, the temperature was raised to 180 ° C. for dehydration, followed by distillation under reduced pressure at 30 torr for 2 hours to obtain 38 g of a novolac type phenol resin.

[Comparative Example 1]
A glass three-necked flask equipped with a thermometer, a charging / distilling outlet and a stirrer was charged with 217 g (0.951 mol) of bisphenol A, 50.6 g (0.708 mol) of 42% formalin, and 1.0 g of oxalic acid. The reaction was carried out at 0 ° C. for 10 hours. Thereafter, the temperature was raised to 180 ° C. for dehydration, followed by distillation under reduced pressure at 30 torr for 2 hours to obtain 180 g of a novolac type phenol resin.

[Comparative Example 2]
In a glass three-necked flask equipped with a thermometer, a charging / distilling outlet and a stirrer, 80 g (0.740 mol) of m-cresol, 120 g (1.110 mol) of p-cresol, 81.3 g of 42% formalin (1.137) Mol) and 0.8 g of oxalic acid were added and reacted at 100 ° C. for 10 hours. Thereafter, the temperature was raised to 180 ° C. for dehydration, and then vacuum distillation was performed at 30 torr for 2 hours to obtain 150 g of a novolac type phenol resin.

[Comparative Example 3]
In a glass three-necked flask equipped with a thermometer, a charging / distilling outlet and a stirrer, m-cresol 100 g (0.925 mol), 50% glutaraldehyde aqueous solution 42.6 g (0.213 mol), and paratoluenesulfonic acid 0 .2 g was added and reacted at 96 ° C. for 20 hours. After completion of the reaction, the mixture was cooled to 90 ° C., 0.2 g of triethylamine was added, 100 g of ion-exchanged water was added, and the mixture was stirred and allowed to stand. The pH of the aqueous layer separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed twice. Thereafter, the temperature was raised to 185 ° C. to dehydrate, and then vacuum distillation was performed at 30 torr for 2 hours to obtain 82 g of a novolak type phenol resin.

[Comparative Example 4]
In a glass three-necked flask equipped with a thermometer, a charging / distilling outlet and a stirrer, m-cresol 50 g (0.462 mol), p-cresol 50 g (0.462 mol), 50% glutaraldehyde aqueous solution 37.0 g (0 .185 mol) and 0.2 g of p-toluenesulfonic acid were added and reacted at 96 ° C. for 20 hours. After completion of the reaction, the mixture was cooled to 90 ° C., 0.2 g of triethylamine was added, 100 g of ion-exchanged water was added, and the mixture was stirred and allowed to stand. The pH of the aqueous layer separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed twice. Then, after heating up to 185 degreeC and dehydrating, it distilled under reduced pressure at 30 torr for 2 hours, and obtained 64 g of novolak-type phenol resins which concern on the comparative example 4.

[Comparative Example 5]
In a glass three-necked flask equipped with a thermometer, a charging / distilling outlet, and a stirrer, m-cresol 40 g (0.370 mol), p-cresol 60 g (0.555 mol), 50% glutaraldehyde aqueous solution 37.0 g (0 .185 mol) and 0.2 g of p-toluenesulfonic acid were added and reacted at 96 ° C. for 20 hours. Thereafter, 13.2 g (0.185 mol) of 42% aqueous formaldehyde solution was added to the reaction mixture, and the mixture was further reacted at 96 ° C. for 4 hours. After completion of the reaction, the mixture was cooled to 90 ° C., 0.2 g of triethylamine was added, 100 g of ion-exchanged water was added, and the mixture was stirred and allowed to stand. The pH of the aqueous layer separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed twice. Thereafter, the temperature was raised to 185 ° C. to dehydrate, and then vacuum distillation was performed at 30 torr for 2 hours to obtain 94 g of a novolac type phenol resin.

  About the novolak type phenol resins obtained in Examples 1 to 3 and Comparative Examples 1 to 5, the chemical composition, molar ratio, analytical evaluation results as resins, and evaluation results as photoresist compositions are shown in the following table. 1 is shown collectively.

  From the above, the novolak type phenol resins of Examples 1 to 3 are the novolak type phenol resin using bisphenol A of Comparative Example 1 and the conventional general novolak type phenol resin using m, p-cresol of Comparative Example 2. It can be seen that the flexibility was improved in spite of the low weight average molecular weight, and the performance of the remaining film ratio and resolution was satisfied in a balanced manner. Moreover, the softness | flexibility is further improved rather than the novolak-type phenol resin of the comparative examples 3-5 corresponding to the novolak-type phenol resin in which the softness | flexibility of patent document 1 was improved. In particular, since the novolak-type phenol resin obtained in Example 3 has a weight average molecular weight in a particularly preferable range of 1000 to 10000, the flexibility and resolution of a photoresist composition prepared using it are good. In addition, the characteristics as a photoresist were extremely excellent, such as a particularly good residual film ratio.

  ADVANTAGE OF THE INVENTION According to this invention, it can propose about the novolak-type phenol resin by which the softness | flexibility was improved, and its use. In particular, in addition to its use as an epoxy resin composition and its cured product, it has high flexibility and high resolution and a high residual film ratio, which are suitably used in lithography processes when manufacturing semiconductors and LCDs. A novolak-type phenol resin for a photoresist composition and a photoresist composition containing the novolak-type phenol resin can be proposed.

  Moreover, since the photoresist composition using the novolak type phenolic resin of the present invention has a higher level of flexibility, high resolution and a high residual film ratio in a balanced manner, when manufacturing a flexible display or a flexible printed wiring board, etc. It can be particularly preferably used in fine processing such as.

Claims (10)

  A novolak-type phenol resin obtained by condensation polymerization reaction of a phenol component (a) containing a bisphenol having a substituent at the 2,2'-position and a monoaldehyde component (b). The novolak-type phenol resin according to claim 1, wherein the bisphenol having a substituent at the 2,2'-position is represented by the following general formula (4).

(Here, each substituent R ¹ is independently a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, or a phenyl group. X is a divalent group and is a divalent group selected from the group consisting of an alkylene group, an ether group, a thioether group, and a carbonyl group.   The molar ratio [(b) / (a)] of the phenol component (a) containing a bisphenol having a substituent at the 2,2′-position and the monoaldehyde component (b) is 0.45 or more. Item 3. A novolac type phenolic resin according to item 1 or 2.   Item 4. The novolak phenol resin according to any one of Items 1 to 3, wherein the molar ratio [(b) / (a)] is 0.45 or more and less than 1.5, and is used for a photoresist composition. A novolac-type phenol resin represented by the following general formula (1).

(Here, each A is independently composed of a monovalent or divalent group represented by the following general formula (2), and each B is independently a divalent group represented by the following general formula (3). And n represents an integer of 0 to 100.)

(Here, each substituent R ¹ is independently a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, or a phenyl group. X is a divalent group, each independently a divalent group selected from the group consisting of an alkylene group, an ether group, a thioether group, and a carbonyl group.

(Here, each substituent R ² is independently a hydrogen group, a linear alkyl group having 1 to 6 carbon atoms, an alkyl group having a branch having 1 to 6 carbon atoms, or a group having 5 to 6 carbon atoms. The substituent R ³ is each independently a hydrogen group, a hydroxyl group, a methyl group, or a methoxy group, and m is an integer of 1 to ^3. )   A photoresist composition comprising the novolak type phenol resin according to claim 4 or 5.   An epoxy resin obtained by epoxidizing the novolac type phenol resin according to claim 1, 2, 3 or 5.   An epoxy resin composition comprising the epoxy resin according to claim 7.   An epoxy resin composition comprising one or more of the novolac type phenol resins according to claim 1, 2, 3, and 5, and an epoxy resin. 10. A cured product obtained by curing the epoxy resin composition according to item 8 or 9.