JPWO2010050592A1 - Phenol resin for photoresist, photoresist composition containing the same, and method for producing the same - Google Patents

Abstract

Provided are a phenolic resin for a photoresist that exhibits high flexibility, high heat resistance, high sensitivity, and high resolution, a photoresist composition containing the same, and a method for producing the same. It is obtained by condensation reaction of methylphenols (a) containing at least one of metacresol and paracresol and dialdehydes (b) containing at least one of glutaraldehyde and adipaldehyde. It is the phenol resin for photoresist characterized.

Description

  The present invention relates to a phenol resin for a photoresist used for lithography in manufacturing a semiconductor or an LCD, a photoresist composition containing the same, and a method for manufacturing the same.

  Generally, a positive photoresist composition containing an alkali-soluble resin such as a novolak-type phenol resin and a photosensitizer having a quinonediazide group such as a naphthoquinonediazide compound is used. Such a positive photoresist composition exhibits high resolving power when developed with an alkaline solution. In addition, the novolac type phenol resin has high heat resistance due to the structure having many aromatic rings with respect to dry etching after exposure. Therefore, a number of positive photoresist compositions containing novolak-type phenolic resin and naphthoquinone diazide photosensitizer have been developed and put to practical use for the manufacture of semiconductors such as IC and LSI, and circuit substrates such as LCD. It's being used.

  In the field of flexible printed wiring boards such as mobile phones, negative dry film photoresists are widely used because the resolution may be about 30 to 300 μm. When a negative dry film photoresist is used, it is difficult to finely process the substrate surface. On the other hand, by using a positive photoresist composition, it is possible to finely process a wide variety of substrate surfaces, for example, from a fine dimension of about 0.3 μm to a large dimension width of about several tens to several hundreds of μm. Yes (see, for example, Patent Documents 1 and 2).

Japanese Patent Application Laid-Open No. 06-59445 JP 08-44053 A

  However, since a dry film formed from a positive photoresist composition is brittle and lacks flexibility, there is a difficulty in making it into a roll product. Moreover, even if it is manufactured as a roll-shaped product, problems are likely to occur when it is used. Therefore, a dry film using a positive photoresist composition has not been put into practical use. Accordingly, the present invention provides a phenolic resin for photoresists that exhibits high flexibility, high heat resistance, high sensitivity, and high resolution, a photoresist composition containing the same, and a method for producing the same. Objective.

  In order to achieve the above object, as a result of intensive studies, the inventors of the present invention have found that methylphenols (a) containing at least one of metacresol and paracresol, glutaraldehyde, and azide. Phenol for photoresist which shows high flexibility, high heat resistance, high sensitivity and high resolution by condensing with dialdehydes (b) containing at least one of paldehyde (Adipaldehyde) It has been found that a resin can be obtained. That is, the present invention provides a condensation reaction between methylphenols (a) containing at least one of metacresol and paracresol and dialdehydes (b) containing at least one of glutaraldehyde and adipaldehyde. It is a phenol resin for photoresists characterized by being obtained. Moreover, this invention is a photoresist composition containing the said phenol resin for photoresists. Furthermore, the present invention provides a condensation reaction between methylphenols (a) containing at least one of metacresol and paracresol and dialdehydes (b) containing at least one of glutaraldehyde and adipaldehyde. It is a manufacturing method of the phenol resin for photoresists characterized by including the process to do.

  As described above, according to the present invention, a phenol resin for a photoresist that exhibits high flexibility, has high heat resistance and high sensitivity, and enables high resolution, a photoresist composition containing the phenol resin, and production thereof A method can be provided.

  In the phenol resin for photoresists according to the present invention, the methylphenol (a) contains metacresol (m-cresol) or para-cresol (p-cresol) alone or a mixture of meta-cresol and para-cresol. However, it preferably comprises at least one of metacresol and paracresol. When methylphenol (a) contains a mixture of metacresol and paracresol, the mixing ratio is not particularly limited, but it is preferable that paracresol is 0.05 to 20 mol per 1 mol of metacresol. More preferably, it is 0.5-2 mol.

  The methylphenol (a) may contain methylphenol other than metacresol and paracresol. Such methylphenols include orthocresol (o-cresol), xylenols, and trimethylphenols. The xylenols include 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, and 3, Examples of each structural isomer of 5-xylenol. Examples of trimethylphenols include 2,3,5-trimethylphenol and 2,3,6-trimethylphenol structural isomers. The total amount of methylphenols other than metacresol and paracresol does not exceed the total amount of metacresol and paracresol, which are the main components, but is 0.3 times the total amount of metacresol and paracresol. The following is preferable.

  In the phenol resin for photoresists according to the present invention, the dialdehyde (b) contains at least one of glutaraldehyde and adipaldehyde, but preferably comprises at least one of glutaraldehyde and adipaldehyde. .

  The dialdehydes (b) may contain dialdehydes other than glutaraldehyde and adipaldehyde. Examples of such dialdehydes include succinaldehyde, and these are preferably used. The total amount of dialdehydes other than glutaraldehyde is preferably less than or equal to the total number of moles of glutaraldehyde and adipaldehyde. The dialdehyde (b) is used as a crosslinking group.

  The molar ratio (b / a) between the dialdehydes (b) and the methylphenols (a) is preferably 0.10 to 0.70, more preferably 0.15 to 0.50. 0.20 to 0.35 is particularly preferable. If it is lower than 0.10, the weight-average molecular weight of the phenol resin for photoresist becomes small, so that the dissolution rate becomes large and the reaction control at the time of dissolution tends to be difficult, which is not preferable. If it is larger than 0.70, the resolution as a photoresist may decrease, which is not preferable.

  An acid catalyst is preferably used for the condensation reaction of the methylphenols (a) and the dialdehydes (b). Examples of the acid catalyst include organic sulfonic acids such as benzenesulfonic acid, paratoluenesulfonic acid, and methanesulfonic acid, organic dicarboxylic acids such as oxalic acid, and inorganic acids such as hydrochloric acid and sulfuric acid. Organic sulfonic acids such as sulfonic acid, paratoluenesulfonic acid, and methanesulfonic acid, and inorganic acids such as hydrochloric acid and sulfuric acid are preferred. The amount of the acid catalyst used can be, for example, 0.01% by weight to 5% by weight with respect to the methylphenols (a). In order to improve the characteristics of the photoresist composition, the acid catalyst is used as much as possible. It is preferable to reduce it.

  A reaction solvent can be used for the condensation reaction of methylphenols (a) and dialdehydes (b). Water that dissolves methylphenol itself or dialdehyde may serve as a reaction solvent, or an organic solvent that does not affect the condensation reaction may be used in some cases. Examples of the organic solvent include alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, and propylene glycol; ethers of polyols such as diethylene glycol dimethyl ether, 1,2-dimethoxyethane, and 1,2-diethoxyethane; propylene Examples include polyol esters such as glycol monomethyl ether acetate; and cyclic ethers such as tetrahydrofuran and dioxane. Preferred are esters of polyols such as propylene glycol monomethyl ether acetate; and cyclic ethers such as tetrahydrofuran and dioxane, and more preferred are esters of polyols such as propylene glycol monomethyl ether acetate. , Propylene glycol monomethyl ether acetate. The amount of the organic solvent used is usually 20 to 1000 parts by weight per 100 parts by weight of the reaction raw material.

  The reaction temperature is usually 50 to 200 ° C, preferably 70 to 180 ° C, more preferably 80 to 180 ° C, although it depends on the blending ratio of methylphenols (a) and dialdehydes (b) to be used. . When the temperature is lower than 50 ° C., the polymerization is very slow. When the temperature is higher than 200 ° C., it becomes difficult to control the reaction, and it becomes difficult to stably obtain the target phenol resin for photoresist. Although the reaction time depends on the reaction temperature, it is usually within 20 hours. The reaction pressure is usually carried out under normal pressure, but it can also be carried out under slight pressure or reduced pressure.

  After completion of the condensation reaction, it is preferable to add a base to stop the reaction to neutralize the acid catalyst, and then add water to remove the acid catalyst and carry out water washing. The base for neutralizing the acid catalyst is not particularly limited, and any base that neutralizes the acid catalyst and forms a water-soluble salt can be used. And inorganic bases such as metal carbonates, and organic bases such as amines and organic amines, with organic amines being preferred. Examples of the inorganic base include sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium hydrogen carbonate, and calcium carbonate. Organic bases include ammonia, trimethylamine, triethylamine, diethylamine, and tributylamine.

  The amount of the base used to neutralize the acid catalyst depends on the amount of the acid catalyst, but should be used in such an amount that the acid catalyst is neutralized and the pH in the reaction system falls within the range of 4-8. Is preferred. The amount and number of washing water used for washing are not particularly limited, but may be any amount and number of times that can remove the acid catalyst to an amount that does not affect actual use, including an economic viewpoint. 1 to 5 times is preferable. Although the washing temperature is not particularly limited, it is preferably performed at 40 to 95 ° C. from the viewpoint of the efficiency of removing the acid catalyst and the workability. When the separation of the phenol resin for photoresist and the washing water is poor, it is effective to add a solvent that lowers the viscosity of the phenol resin for photoresist and raise the washing temperature. Such solvent species is not particularly limited, and any solvent can be used as long as it dissolves the phenol resin and lowers the viscosity.

  After removing the acid catalyst, generally, the temperature of the reaction system is raised to 130 ° C. to 230 ° C., and unreacted raw materials and organic solvents present in the reaction system under reduced pressure, for example, 5 to 50 torr. The phenolic resin for photoresist can be recovered by distilling off volatile components such as the above.

  Although the weight average molecular weight of the phenol resin for photoresists according to the present invention is not particularly limited, it is preferably 2000 to 60000, and preferably 4000 to 50000 in view of the performance of the photoresist composition and the handleability in production. More preferred is 5,000 to 50,000. When the weight average molecular weight is less than 2000, the sensitivity is too high and the heat resistance is poor, and when it is more than 60000, the sensitivity is too low to be suitable for actual use.

  The softening point of the phenol resin for photoresists according to the present invention is preferably 140 ° C. or higher, more preferably 150 ° C. or higher, and particularly preferably 160 ° C. or higher from the viewpoint of heat resistance. When the softening point is lower than 140 ° C., it may be inferior in heat resistance when used as a photoresist.

  The photoresist composition according to the present invention preferably includes the phenol resin for photoresist according to the present invention, and further includes a photosensitizer.

  The photosensitizer is preferably a compound containing a quinonediazide group, and more preferably a 1,2-quinonediazide compound. As the compound containing a quinonediazide group, any of known photosensitizers conventionally used in quinonediazide-novolak resists can be used. As such a photosensitizer, a compound obtained by reacting naphthoquinone diazide sulfonic acid chloride, benzoquinone diazide sulfonic acid chloride or the like with a low molecular compound or a high molecular compound having a functional group capable of condensation reaction with these acid chlorides. Is preferred.

  As acid chlorides such as naphthoquinone diazide sulfonic acid chloride and benzoquinone diazide sulfonic acid chloride, 1,2-naphthoquinone diazide-5-sulfonyl chloride and 1,2-naphthoquinone diazide-4-sulfonyl chloride are preferable.

  Examples of the functional group capable of condensing with an acid chloride include a hydroxyl group and an amino group, and a hydroxyl group is preferred. Compounds that can be condensed with an acid chloride containing a hydroxyl group include hydroquinone, resorcin, 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,4,4 ' -Trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2', 3,4,6'-pentahydroxybenzophenone, etc. Hydroxyphenylalkanes such as hydroxybenzophenones, bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, and bis (2,4-dihydroxyphenyl) propane, and 4 , 4 ', 3 ", 4" -tetrahydroxy-3,5 Hydroxytriphenyl such as 3 ′, 5′-tetramethyltriphenylmethane and 4,4 ′, 2 ″, 3 ″, 4 ″ -pentahydroxy-3,5,3 ′, 5′-tetramethyltriphenylmethane Examples thereof include methanes, which may be used alone or in combination of two or more.

  The blending amount of the photosensitizer is usually 5 to 50 parts by weight, preferably 10 to 40 parts by weight per 100 parts by weight of the phenol resin for photoresist. If it is less than this, sufficient sensitivity as a photoresist composition may not be obtained, and if it is more than this, a problem of precipitation of components may occur.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, a part shows a weight part.
Analytical methods such as component content and physical properties of the resin are as follows.
(1) (GPC measurement method)
Model: HLC-8220 Tosoh Co., Ltd. column: TSK-GEL H type G2000H × L 4 G3000H × L 1 G4000H × L 1 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

[Example 1]
In a glass flask having a capacity of 500 parts by volume equipped with a thermometer, a charging / distilling outlet and a stirrer, 200 parts (1.85 mol) of metacresol, 76.0 parts (0.38 mol) of a 50 wt% aqueous glutaraldehyde solution, para After placing 0.4 parts of toluenesulfonic acid in a three-necked flask and reacting at 100 ° C. for 10 hours, cooling to 80 ° C., adding 0.3 parts of triethylamine, adding 110 parts of ion-exchanged water, stirring and static I put it. The pH of the separated water 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 180 degreeC and dehydrating, it distilled under reduced pressure at 30 torr for 2 hours, and obtained 164 parts of phenol resins for photoresists concerning Example 1. The low molecular weight component below the dimer in the obtained phenol resin for photoresist was 1.5% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 4497. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the obtained phenol resin for photoresist.

[Example 2]
In a glass flask having a capacity of 500 parts by volume equipped with a thermometer, a charging / distilling outlet and a stirrer, 200 parts (1.85 mol) of metacresol, 85.3 parts (0.43 mol) of a 50 wt% aqueous solution of glutaraldehyde, para After placing 0.4 parts of toluenesulfonic acid in a three-necked flask and reacting at 100 ° C. for 10 hours, cooling to 80 ° C., adding 0.3 parts of triethylamine, adding 110 parts of ion-exchanged water, stirring and static I put it. The pH of the separated water 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 180 degreeC and dehydrating, it distilled under reduced pressure at 30 torr for 2 hours, and obtained 166 parts of phenol resins for photoresists concerning Example 2. The low molecular weight component below the dimer in the obtained phenol resin for photoresist was 1.5% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 8090. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the obtained phenol resin for photoresist.

[Example 3]
In a glass flask having a capacity of 500 parts by volume equipped with a thermometer, a charging / distilling outlet and a stirrer, 200 parts (1.85 mol) of metacresol, 113.8 parts (0.57 mol) of a 50% by weight aqueous glutaraldehyde solution, propylene 100 parts of glycol monomethyl ether acetate and 0.4 part of paratoluenesulfonic acid are placed in a three-necked flask, reacted at 100 ° C. for 10 hours, cooled to 80 ° C., added with 0.3 part of triethylamine, and ion-exchanged water 110 Part was added and stirred and allowed to stand. The pH of the separated water 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 200 degreeC and dehydrating, it distilled under reduced pressure at 30 torr for 2 hours, and obtained 170 parts of phenol resins for photoresists concerning Example 3. The low molecular weight component below the dimer in the obtained phenol resin for photoresist was 2.3% as a result of gel permeation chromatographic analysis (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 49142. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the obtained phenol resin for photoresist.

[Example 4]
In a glass flask having a capacity of 500 parts by volume equipped with a thermometer, a charging / discharging outlet and a stirrer, 100 parts (0.93 mol) of metacresol, 100 parts (0.93 mol) of paracresol, and a 50 wt% aqueous solution of glutaraldehyde 74 .2 parts (0.37 mol) and 0.4 parts of paratoluenesulfonic acid were placed in a three-necked flask and reacted at 100 ° C. for 10 hours, then cooled to 80 ° C. and added with 0.3 parts of triethylamine, 110 parts of exchange water was added and stirred and allowed to stand. The pH of the separated water 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 180 degreeC and dehydrating, it distilled under reduced pressure at 30 torr for 2 hours, and obtained 158 parts of phenol resins for photoresists concerning Example 4. The low molecular weight component below the dimer in the obtained phenol resin for photoresists was 1.7% as a result of gel permeation chromatographic analysis (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 9362. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the obtained phenol resin for photoresist.

[Example 5]
In a glass flask having a capacity of 500 parts by volume equipped with a thermometer, a charging / distilling outlet and a stirrer, 200 parts (1.85 mol) of metacresol, 227.7 parts (1.14 mol) of a 50 wt% aqueous solution of glutaraldehyde and oxalic acid After 0.1 part was put into a three-necked flask and reacted at 100 ° C. for 16 hours, 110 parts of ion-exchanged water was added and stirred and allowed to stand. Separated water was removed by standing. This operation was performed twice. Then, after heating up to 180 degreeC and dehydrating, it distilled under reduced pressure at 30 torr for 2 hours, and obtained 110 parts of phenol resins for photoresists concerning Example 5. The low molecular weight component below the dimer in the obtained phenol resin for photoresists was 13.2% as a result of gel permeation chromatographic analysis (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 2520. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the obtained phenol resin for photoresist.

[Example 6]
Example 1 except that 160 parts (1.48 moles) of metacresol, 40 parts (0.37 moles) of paracresol, and 74.2 parts (0.37 moles) of a 50 wt% aqueous solution of glutaraldehyde were used. Thus, a novolac-type photoresist phenol resin according to Example 6 was obtained. As a result of gel permeation chromatographic analysis (GPC) measurement, the low molecular weight component below the dimer in the obtained phenol resin for photoresists was 2.0%. Moreover, the weight average molecular weight by GPC measurement was 4668. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the obtained phenol resin for photoresist.

[Example 7]
Same as Example 1 except that 120 parts (1.11 moles) of metacresol, 80 parts (0.74 moles) of paracresol, and 59.3 parts (0.30 moles) of 50% by weight aqueous glutaraldehyde solution were used. Thus, a novolak-type photoresist phenol resin according to Example 7 according to Example 7 was obtained. The low molecular weight component below the dimer in the obtained phenol resin for photoresist was 3.0% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 3490. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the obtained phenol resin for photoresist.

[Example 8]
Same as Example 1 except that 120 parts (1.11 moles) of metacresol, 80 parts (0.74 moles) of paracresol, and 77.9 parts (0.39 moles) of 50% by weight aqueous glutaraldehyde solution were used. Thus, a novolak phenol resin for photoresist according to Example 8 was obtained. The low molecular weight component below the dimer in the obtained phenol resin for photoresist was 1.1% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 9500. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the resulting novolak resist resin.

[Example 9]
Example 1 except that 100 parts (0.93 mole) of metacresol, 100 parts (0.93 mole) of paracresol, and 59.3 parts (0.30 mole) of a 50 wt% aqueous solution of glutaraldehyde were used. Thus, a phenol resin for photoresist according to Example 9 of a novolak type was obtained. The low molecular weight component below the dimer in the obtained phenol resin for photoresist was 4.2% as a result of gel permeation chromatographic analysis (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 3980. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the obtained phenol resin for photoresist.

[Example 10]
Same as Example 1 except that 80 parts (0.74 mole) of metacresol, 120 parts (1.11 mole) of paracresol and 59.3 parts (0.30 mole) of 50% by weight aqueous glutaraldehyde solution were used. Thus, a novolac-type photoresist phenol resin according to Example 10 was obtained. The low molecular weight component below the dimer in the obtained phenol resin for photoresists was 1.6% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 4790. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the obtained phenol resin for photoresist.

[Example 11]
Same as Example 1 except that 80 parts (0.74 mole) of metacresol, 120 parts (1.11 mole) of paracresol and 74.2 parts (0.37 mole) of 50% by weight aqueous glutaraldehyde solution were used. Thus, a novolac-type photoresist phenol resin according to Example 11 was obtained. The low molecular weight component below the dimer in the obtained phenol resin for photoresist was 3.2% as a result of gel permeation chromatographic analysis (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 8625. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the resulting novolak resist resin.

[Example 12]
Same as Example 1 except that 40 parts (0.37 moles) of metacresol, 160 parts (1.48 moles) of paracresol, and 74.2 parts (0.37 moles) of 50% by weight aqueous glutaraldehyde solution were used. Thus, a novolac-type photoresist phenol resin according to Example 12 was obtained. The low molecular weight component below the dimer in the obtained phenol resin for photoresist was 1.5% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 4543. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the resulting novolak resist resin.

[Example 13]
Photo of Novolak Example 13 in the same manner as Example 1 except that 200 parts (1.85 mol) of metacresol and 63.3 parts (0.56 mol) of 100 wt% adipaldehyde were used. A phenol resin for resist was obtained. The low molecular weight component below the dimer in the obtained phenol resin for photoresists was 4.6% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 3095. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the resulting novolak resist resin.

[Example 14]
Photo of novolak type Example 14 in the same manner as in Example 1 except that 200 parts (1.85 mol) of metacresol and 84.4 parts (0.74 mol) of 100 wt% adipaldehyde were used. A phenol resin for resist was obtained. The low molecular weight component below the dimer in the obtained phenol resin for photoresist was 3.8% as a result of gel permeation chromatographic analysis (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 6726. Table 1 shows the condensation conditions, and Table 3 shows the physical properties of the resulting novolak resist resin.

[Comparative Example 1]
In a glass flask having a capacity of 500 parts by volume equipped with a thermometer, a charging / distilling outlet and a stirrer, 80 parts (0.74 mol) of metacresol, 120 parts (1.11 mol) of paracresol, a 42 wt% formalin aqueous solution 81. 3 parts (1.14 mol) and 0.8 part of oxalic acid were placed in a three-necked flask and reacted at 100 ° C. for 10 hours, and then heated to 180 ° C. for dehydration. Thereafter, distillation under reduced pressure was performed at 30 torr for 2 hours to obtain 150 parts of a novolac type phenol resin according to Comparative Example 1. The low molecular weight component below the dimer in the obtained novolak type phenol resin was 8.5% as a result of gel permeation chromatographic analysis (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 5940. Table 2 shows the condensation conditions, and Table 4 shows the physical properties of the obtained novolak type phenol resin.

[Comparative Example 2]
A glass flask having a capacity of 500 parts by volume equipped with a thermometer, a charging / discharging outlet and a stirrer, 200 parts (1.85 mol) of metacresol, 134.3 parts (0.93 mol) of a 40 wt% aqueous solution of glyoxal, propylene glycol 60 parts of monomethyl ether acetate and 0.4 part of paratoluenesulfonic acid are placed in a three-necked flask, reacted at 100 ° C. for 8 hours, cooled to 80 ° C., added with 0.3 part of triethylamine, and 110 parts of ion-exchanged water. Was added and stirred and allowed to stand. The pH of the separated water 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 180 degreeC and dehydrating, it vacuum-distilled at 30 torr for 2 hours, and 198 parts of novolak-type phenol resins which concern on the comparative example 2 were obtained. The low molecular weight component below the dimer in the obtained novolak type phenol resin was 13.2% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 1096. Table 2 shows the condensation conditions, and Table 4 shows the physical properties of the obtained novolak type phenol resin.

[Comparative Example 3]
A novolak-type phenolic resin according to Comparative Example 3 in the same manner as Comparative Example 2 except that 200 parts (1.85 mol) of metacresol and 161.1 parts (1.11 mol) of 40 wt% aqueous glyoxal solution were used. Got. The low molecular weight component below the dimer in the obtained novolak type phenol resin was 13.8% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 1674. Table 2 shows the condensation conditions, and Table 4 shows the physical properties of the obtained novolak type phenol resin.

[Comparative Example 4]
Similar to Comparative Example 2, except that 80 parts (0.74 mole) of metacresol, 120 parts (1.11 mole) of paracresol, and 107.4 parts (0.74 mole) of 40 wt% aqueous glyoxal solution were used. Thus, a novolac type phenol resin according to Comparative Example 4 was obtained. The low molecular weight component below the dimer in the obtained novolak type phenol resin was 11.0% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 1189. Table 2 shows the condensation conditions, and Table 4 shows the physical properties of the obtained novolak type phenol resin.

[Comparative Example 5]
After adding 200 parts (1.85 moles) of metacresol, 39.7 parts (0.56 moles) of 42% by weight formalin aqueous solution and 0.8 parts of oxalic acid to a three-necked flask and reacting them at 100 ° C. for 10 hours, The temperature was raised to ℃ and dehydrated. Thereafter, distillation under reduced pressure was performed at 30 torr for 2 hours to obtain 105 parts of a novolak type phenol resin according to Comparative Example 5. The low molecular weight component below the dimer in the obtained novolak type phenol resin was 23.1% as a result of gel permeation chromatographic analysis (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 612. Table 2 shows the condensation conditions, and Table 4 shows the physical properties of the resulting novolak resist resin.

[Comparative Example 6]
The novolak-type phenolic resin according to Comparative Example 6 is the same as Comparative Example 2 except that 200 parts (1.85 mol) of metacresol and 80.6 parts (0.56 mol) of a 40 wt% aqueous solution of glyoxal are used. Got. The low molecular weight component below the dimer in the obtained novolak type phenol resin was 16.7% as a result of gel permeation chromatography analysis (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 621. Table 2 shows the condensation conditions, and Table 4 shows the physical properties of the obtained novolak type phenol resin.

[Comparative Example 7]
In a glass flask having a capacity of 500 parts by volume equipped with a thermometer, a charging / distilling outlet and a stirrer, 59.5 parts (0.55 mol) of metacresol, 42.8 parts (0.35 mol) of 2,3-xylenol, Into a three-necked flask, 12.2 parts (0.1 mol) of 3,4-xylenol, 108.8 parts (0.75 mol) of 40 wt% aqueous glyoxal solution, and 2.5 parts of oxalic acid were added at 100 ° C. for 2 hours. After the reaction, 115 parts of dioxane and 40.6 parts (0.50 mol) of a 37 wt% formalin aqueous solution were added, and the mixture was further reacted for 2 hours. Then, after heating up to 180 degreeC and dehydrating, it distilled under reduced pressure at 30 torr for 2 hours, and obtained 95 parts of novolak type phenol resins. The obtained novolac type phenol resin was dissolved in ethyl acetate to make a 30% solution, 1.15 times as much methanol as the solution was added, and then 0.75 times as much pure water as the solution was added and stirred. Thereafter, the lower layer separated into two layers was taken out, concentrated and dried to obtain a novolac type phenol resin according to Comparative Example 7. The low molecular weight component below the dimer in 75 parts of the obtained novolak type phenol resin was 1.1% as a result of gel permeation chromatography (GPC) measurement. Moreover, the weight average molecular weight by GPC measurement was 8210. Table 2 shows the condensation conditions, and Table 4 shows the physical properties of the obtained novolak type phenol resin.

<< Evaluation Example 1 >> Evaluation of Dissolution Rate The phenolic resin for photoresist according to Examples 1 to 14 and the novolak type phenol resin according to Comparative Examples 1 to 7 were dissolved in PGMEA (propylene glycol monomethyl ether acetate), respectively. A resin solution was prepared. This was 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 (2.38% 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. The results are shown in Tables 3 and 4.

<< Evaluation Example 2 >> Evaluation of Flexibility The phenolic resin for photoresist according to Examples 1 to 14 and the novolak type phenol resin according to Comparative Examples 1 to 7 were dissolved in PGMEA (propylene glycol monomethyl ether acetate), respectively. A resin solution was prepared. This was 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. Subsequently, it bent at 180 degree | times and evaluated the state of the bending location visually by the following reference | standard.
○: Resin powder does not scatter ×: Resin powder scatter results are shown in Tables 3 and 4.

<< Evaluation Example 3 >> Sensitivity of Photoresist Composition 20 parts each of phenolic resin for photoresist according to Examples 1 to 14 and novolac type phenol resin according to Comparative Examples 1 to 7, and naphthoquinone 1,2-diazide- A resist solution was prepared by dissolving 5 parts of 2,3,4,4′-tetrahydroxybenzophenone ester of 5-sulfonic acid in PGMEA (propylene glycol monomethyl ether acetate). This was filtered through a 0.2 micron membrane filter to obtain a resist solution. 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. Thereafter, exposure was performed using a reduced projection exposure apparatus while changing the exposure time stepwise. Subsequently, it developed for 60 second using the developing solution (2.38% tetramethylammonium hydroxide aqueous solution). After rinsing and drying, the remaining film ratio was determined from the remaining film thickness of the unexposed area. The resolution was evaluated according to the following criteria using a test chart mask.
○: 2.0 μ line & space can be resolved ×: 2.0 μ line & space cannot be resolved are shown in Tables 5 and 6.

<< Evaluation Example 4 >> Flexibility of Photoresist Composition 32 parts each of phenol resin for photoresists according to Examples 1 to 14 and novolac type phenol resin according to Comparative Examples 1 to 7, and naphthoquinone 1,2-diazide A resist solution was prepared by dissolving 8 parts of 2,3,4,4′-tetrahydroxybenzophenone ester of -5-sulfonic acid in PGMEA (propylene glycol monomethyl ether acetate). These were filtered through a 0.2 micron membrane filter to obtain a resist solution. 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. Then, 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 visually evaluated according to the following criteria.
○: There is no cracking of the resist film. X: The results of cracking of the resist film are shown in Tables 5 and 6.

<< Evaluation Example 5 >> Physical Properties of Phenolic Resin for Photoresist Storage Elastic Modulus of Phenolic Resin and Rise Temperature of Tan δ Obtained Phenolic Resin for Photoresist According to Examples 1 to 14 and Novolak According to Comparative Examples 1 to 7 Each type phenol resin was melted to prepare a columnar test piece having a length of 10 mm and a diameter of 10 mm, and then using a viscoelastic spectrometer EXSTAR DMS6100 (manufactured by Seiko Instruments Inc.), the vibration frequency was 1 Hz and the temperature was raised. The storage elastic modulus (E ′) and tan δ were measured in the compression mode in the length direction at a rate of 3 ° C./min and a temperature range of 30 to 140 ° C. The value (Pa) of the storage elastic modulus at 70 ° C. from the obtained storage elastic modulus-temperature curve was defined as the storage elastic modulus of the phenol resin. In addition, the one where a storage elastic modulus (E ') is lower has shown that a softness | flexibility is good. For tan δ, the rising temperature (° C.) was used as an index of heat resistance from the obtained tan δ-temperature curve. In addition, the one where a numerical value is high has shown that heat resistance is high. The results are shown in Table 7.

Claims (11)

  It is obtained by a condensation reaction of methylphenols (a) containing at least one of metacresol and paracresol and dialdehydes (b) containing at least one of glutaraldehyde and adipaldehyde. Feature phenol resin for photoresist.   2. The methylphenol (a) comprises at least one of metacresol and paracresol, and the dialdehyde (b) comprises at least one of glutaraldehyde and adipaldehyde. Phenol resin for photoresist.   The phenol resin for photoresists according to claim 1 or 2, wherein a molar ratio (b / a) of the methylphenols (a) to the dialdehydes (b) is 0.10 to 0.70. .   The phenol resin for photoresists according to any one of claims 1 to 3, wherein the phenol resin for photoresists has a weight average molecular weight of 2000 to 60000.   The phenol resin for a photoresist according to claim 4, wherein the weight average molecular weight is 4000 to 50000.   A photoresist composition comprising the phenol resin for photoresists according to claim 1.   The photoresist composition according to claim 6, further comprising a photosensitizer.   The photoresist composition according to claim 7, wherein the photosensitive agent is a compound containing a quinonediazide group.   A step of subjecting a methylphenol (a) containing at least one of metacresol and paracresol to a condensation reaction with a dialdehyde (b) containing at least one of glutaraldehyde and adipaldehyde; A method for producing a phenolic resin for photoresist, which is characterized by the following.   10. The methylphenol (a) comprises at least one of metacresol and paracresol, and the dialdehyde (b) comprises at least one of glutaraldehyde and adipaldehyde. Manufacturing method of phenol resin for photoresist.   The phenol resin for photoresists according to claim 9 or 10, wherein the molar ratio (b / a) between the methylphenols (a) and the dialdehydes (b) is 0.10 to 0.70. Manufacturing method.