JP2006096824A - Method for producing phenolic resin for photoresist and resin composition for photoresist - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a resin for photoresist having improved productivity by reducing the contamination of the production line with sublimed material in the photoresist resin and provide a composition for photoresist. <P>SOLUTION: The method for the production of a phenolic resin for photoresist comprises the step A to pass a phenolic resin dissolved in an organic solvent through a column packed with an adsorbent and the step B to perform the reaction and/or concentration of the phenolic resin processed by the step A. The invention further provides a resin composition for photoresist containing the resin for photoresist, a photosensitizing agent and a solvent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a phenol resin for photoresist and a resin composition for photoresist.

  In general, a positive photoresist uses a photosensitizer having a quinonediazide group such as a naphthoquinonediazide compound and an alkali-soluble resin (for example, a novolac-type phenolic resin). A positive photoresist having such a composition exhibits a high resolving power by developing with an alkaline solution after exposure, and is used for manufacturing semiconductors such as IC and LSI, display screen devices such as LCDs, and printing masters. Yes. In addition, novolak type phenolic resin has high heat resistance due to the structure having many aromatic rings against plasma dry etching, and so far it contains novolak type phenolic resin and naphthoquinone diazide photosensitizer. Many positive-type photoresists have been developed and put to practical use and have achieved great results.

As the positive photoresist, a novolak type phenol resin obtained by reacting m− / p-cresol and formaldehyde in the presence of an acid catalyst is generally used. In order to adjust or improve the characteristics of the photoresist, studies have been made on the ratio of m- / p-cresol used as raw material phenols, the molecular weight of the phenol resin, the molecular weight distribution, and the like.
However, in a photoresist to which a resin obtained by a general method from m / p-cresol and formaldehyde is applied, for example, in the LCD manufacturing process, a low-nuclear component (mainly binuclear) of a phenol resin in the photoresist. Sublimation of the component) causes the sublimate to accumulate and contaminate the production line, causing a reduction in product yield. For this reason, the reduction | decrease request | requirement of the binuclear component of a phenol resin has become very high.

Such a phenol resin having a small amount of a binuclear component is synthesized by a method such as solvent fractionation (for example, see Patent Document 1), removal of the dinuclear component by steam distillation (for example, see Patent Document 2), or the like. There are examples. Solvent fractionation is a technique that utilizes the difference in solubility between good and poor solvents, but there is no clear solubility difference between phenolic low nuclei, so the binuclear component must be selectively removed. Is difficult. For this reason, excess resin was removed, resulting in a disadvantage that the batch yield was reduced and the production was not possible at a low cost. In addition, since the removal efficiency of the dinuclear body is low, repeated operations are required, and a large amount of a solution of the removal component is generated, resulting in a high environmental load.
On the other hand, the steam distillation method is a technique in which high pressure steam is blown into the resin under vacuum conditions to forcibly remove the dinuclear body by azeotropic action, but there is a clear boiling point difference between the low nuclei of the phenol resin. Therefore, the selectivity for dinuclear removal is high. However, not only is it necessary to have robust equipment that can withstand bumping and explosion phenomena that occur when steam is blown into high-temperature resin, but a large amount of high-pressure steam is generated to keep the resin at a high temperature for a long time. Not only is it necessary to produce thermal energy, but a large amount of coagulated water in which two nuclei are dissolved is generated as industrial waste. Not only can it be produced at low cost, but also the technical and environmental impacts of implementation on an industrial scale. Manufacturing technology with high barriers.

JP-T-2001-506294 Japanese Patent Application Laid-Open No. 11-246643

  An object of the present invention is to provide a method for producing a photoresist resin and a photoresist composition, which can reduce the contamination of the production line due to sublimates in the photoresist resin and thereby improve the productivity. is there.

Such an object is achieved by the following present inventions (1) to (6).
(1) A method for producing a phenol resin for a photoresist, which is produced by the following steps A and B.
Step A: Step of passing a phenol resin dissolved in an organic solvent through a column filled with an adsorbent; Step B: Step of reacting and / or concentrating the phenol resin after Step A.
(2) The method for producing a phenol resin for a photoresist according to (1), wherein the phenol resin synthesized by the step A and the step B satisfies the following characteristics.
1.2 Nucleotide component content is 5% or less of the whole resin.
2. The weight average molecular weight measured by GPC is 1000-20000.
(3) The photoresist according to (1) or (2), wherein the phenol resin used in the step A is synthesized from m-cresol, p-cresol, and formaldehyde and satisfies the following characteristics: Of manufacturing phenolic resin.
1. The charging weight ratio of m-cresol and p-cresol is m-cresol / p-cresol = 9/1 to 2/8.
2. The weight average molecular weight measured by GPC is 500-15000.
(4) The method for producing a phenol resin for a photoresist according to any one of (1) to (3), wherein the adsorbent used in the step A is an ion exchange resin or a synthetic adsorbent.
(5) The content of the adsorbent used in the step A is 10 to 500 parts by weight with respect to 100 parts by weight of the phenol resin. (1) The phenol resin for photoresists according to any one of (4) Production method.
(6) A photoresist resin composition comprising the photoresist resin according to any one of (1) to (5), a photosensitive agent, and a solvent.

The method for producing a phenol resin for a photoresist of the present invention is as follows.
Step A: A step of passing a phenol resin dissolved in an organic solvent through a column filled with an adsorbent, and Step B: a step of reacting and / or concentrating the phenol resin after Step A, than the conventional method. A phenol resin for a photoresist with few dinuclear components can be easily produced. By using the photoresist resin composition using the phenol resin produced by the method of the present invention, the contamination of the production line is reduced and the yield is expected to be improved in the LCD production process and the like.

Hereinafter, a method for producing a phenol resin for photoresist of the present invention (hereinafter sometimes referred to as “photoresist resin”) and a resin composition for photoresist (hereinafter sometimes simply referred to as “composition”) will be described. .
The method for producing a photoresist resin of the present invention is as follows.
Step A: a step of passing a phenol resin dissolved in an organic solvent through a column filled with an adsorbent; and Step B: a step of reacting and / or concentrating the phenol resin after Step A. By passing through such a process, a low nuclei such as a binuclear component is adsorbed on an adsorbent to reduce the binuclear component.
In addition, the composition of the present invention is characterized by containing a photoresist resin obtained by the above method, a photosensitive agent, and a solvent.

First, the manufacturing method of the resin for photoresists of this invention is demonstrated.
The method for producing a photoresist resin of the present invention is as follows.
Step A: passing a phenol resin dissolved in an organic solvent through a column filled with an adsorbent,
Step B: react and / or concentrate the phenol resin after Step A,
It goes through the process.

The phenol resin (hereinafter sometimes referred to as “base resin”) used in step A will be described.
Although base resin is not specifically limited, It is preferable that it is a thing obtained by carrying out the condensation reaction in the ratio of 0.5-1.0 mol of aldehydes with respect to 1 mol of phenols under an acidic catalyst. Examples of the phenols used here include cresols such as phenol, o-cresol, m-cresol, and p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2, 6-xylenol, 3,4-xylenol, xylenols such as 3,5-xylenol, ethylphenols such as o-ethylphenol, m-ethylphenol, p-ethylphenol, isopropylphenol, butylphenol, p-tert-butylphenol Alkylphenols such as resorcinol, catechol, hydroquinone, pyrogallol, phloroglucin and other polyhydric phenols, alkylresorcinol, alkylcatechol and alkylhydroquinone and other polyhydric phenols (any alkyl group) , Are used those having 1 to 4 carbon atoms) can be mentioned, it can be used in combination singly or two or more kinds.

Among the above phenols, particularly preferred is the combined use of m-cresol and p-cresol. By using these phenols and adjusting the blending ratio of both, sensitivity as a photoresist, heat resistance, etc. Various characteristics can be adjusted.
When m-cresol and p-cresol are used as the phenols, the ratio is not particularly limited, but is preferably m-cresol / p-cresol (weight ratio) = 9/1 to 2/8. Thereby, a photoresist resin having both excellent heat resistance and sensitivity can be obtained. When the ratio of m-cresol is less than the above lower limit value, the sensitivity may be lowered, and when it exceeds the above upper limit value, the heat resistance may be lowered.
In addition, it is preferable in terms of characteristics to use formaldehyde and paraformaldehyde as the aldehydes.

The acidic catalyst in the above reaction is not particularly limited. For example, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid and phosphorous acid, organic acids such as oxalic acid, diethyl sulfuric acid, paratoluenesulfonic acid and organic phosphonic acid, zinc acetate And metal salts such as These can be used alone or in combination of two or more.

The molecular weight of the base resin is preferably from 500 to 15000 in terms of weight average molecular weight in terms of polystyrene as measured by gel permeation chromatography (GPC). If it is smaller than the lower limit, the heat resistance may be lowered, and if it is larger than the upper limit, the sensitivity may be insufficient.

As the organic solvent in which the base resin is dissolved, any organic solvent that can dissolve the phenol resin to be used can be used. For example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol alkyl ethers such as ethylene glycol monobutyl ether, diethylene glycol dialkyl such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether Propylene such as ethers, ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate Glycol ether ethers, ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl amyl ketone, cyclic ethers such as dioxane, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 2-hydroxy-2 -Ethyl methyl propionate, ethyl ethoxy acetate, ethyl oxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl formate, ethyl acetate, butyl acetate, aceto Examples thereof include esters such as methyl acetate and ethyl acetoacetate, and amides such as N, N′-dimethylformamide. These may be used individually by 1 type, and may be used in mixture of 2 or more types. The amount used is not particularly limited, but the phenol resin concentration is preferably 10 to 60% by weight in order to avoid difficulty in handling due to viscosity.

The adsorbent used in step A is not particularly limited. For example, organic solid acid catalysts such as ion exchange resins, synthetic adsorbents such as polystyrene and polyacrylate, acidic clay, activated clay, bentonite, and montmorillo Viscous minerals such as knight and inorganic solid acid catalysts such as alumina and silica magnesia can be used. Among these, in consideration of prevention of metal contamination in the resin solution, an ion exchange resin or a synthetic adsorbent containing no metal is preferable. Furthermore, since these have pores inside the particles, they have a large adsorption effect, particularly a binuclear adsorption effect. Of these, strong basic ion exchange resins are the most suitable for ion exchange resins, and examples of commercially available products include Amberlite IRA900J and IRA958 made by Organo, and Diaion SA20A made by Mitsubishi Chemical Industries. is there. As the synthetic adsorbent, Diaion HP2MG manufactured by Mitsubishi Chemical Corporation, Sepabead SP200, and the like are optimal.
In the case of using an ion exchange resin or a synthetic adsorbent, the amount added is preferably 10 to 500 parts by weight with respect to 100 parts by weight of the phenol resin. If the amount is less than the lower limit, the dinuclear reduction effect may not be sufficiently obtained, and if the upper limit is exceeded, the resolution increases but the process time may be longer.

The temperature at the time of passing through the column in the step A is not particularly limited and can be appropriately selected according to the conditions such as the adsorbent species and the developing solvent, but generally 20 ° C. or higher is suitable, preferably 60 It is above ℃. Moreover, 120 degrees C or less is suitable. In this temperature range, the adsorption process can be performed efficiently. When temperature is lower than 60 degreeC, the viscosity of a resin solution will increase and a process may become long time. When the temperature is higher than 120 ° C., the resin may change with time.
As a fractionation form of the step A, a column system in which an adsorbent is previously packed in a column or the like and a base resin solution dissolved in a developing solvent is passed therethrough can be mentioned.

  In step B, the phenol resin solution after step A is reacted and / or concentrated. The reaction here refers to guiding to a target molecular weight, and a method such as a high temperature hold or a high molecular weight reaction by addition of aldehydes can be used. Concentration refers to removal of components other than phenolic resins such as unreacted aldehydes, solvents, and moisture, and methods such as simple distillation, vacuum distillation, heat drying, and vacuum drying can be used.

In this invention, it is preferable that the weight average molecular weights measured by GPC are 1000-20000 as a phenol resin obtained after B process. More preferably, it is 1500-15000. By using a resin having such a weight average molecular weight, a photoresist having excellent heat resistance and sensitivity can be obtained. If the weight average molecular weight is smaller than the above lower limit, the heat resistance may decrease, and if it is larger than the above upper limit, the sensitivity may be insufficient.

  The content of the binuclear component of the photoresist resin obtained by the present invention is preferably 5% by weight or less, particularly preferably 4% by weight or less. As a result, sublimates are reduced, thereby improving the productivity. If the content of the binuclear component exceeds the above upper limit, the effect of reducing the sublimate may be reduced.

The weight average molecular weight and the content of the binuclear component can be evaluated by, for example, the following methods.
The weight average molecular weight and the content of the binuclear component are measured by gel permeation chromatography (GPC). The weight average molecular weight was calculated based on a calibration curve prepared using a polystyrene standard. The content of the binuclear component was calculated from the molecular weight distribution curve by the area ratio (%) of the binuclear component to the entire resin. GPC measurement was performed using tetrahydrofuran as an elution solvent under conditions of a flow rate of 1.0 ml / min and a column temperature of 40 ° C.
The following equipment was used.
-Body: HOS-8020 manufactured by TOSOH
-Detector: UV-8011 manufactured by TOSOH Corporation set at a wavelength of 280 nm
・ Analytical column: 1 SHODEX KF-802, 1 KF-803, 1 KF-805 manufactured by Showa Denko KK

In the photoresist resin obtained according to the present invention, the reason why the content of the dinuclear component that becomes a sublimate during use can be reduced is considered as follows.
For the positive photoresist, a novolac type phenol resin obtained by reacting m- / p-cresol and formaldehyde in the presence of an acid catalyst is generally used, but a phenol resin is generally used. When produced by the method, the reactivity of m-cresol is much higher than that of p-cresol, so that the high molecular weight of p-cresol does not proceed sufficiently, and a low-nuclear body mainly composed of p-cresol, In particular, a molecular weight distribution with a high content of dinuclear components is produced. In the conventional method, if the solvent fractionation method is used from this state, other low molecular weight components are also removed at the same time in order to remove the dinuclear component, which is not preferable from the viewpoint of yield. In the production method of the present invention, the dinuclear component can be removed with high selectivity.

Adsorbents such as synthetic adsorbents and ion exchange resins have pores that are suitable for solute diffusion of solutes in the solution that lead from the surface to the inside. When the phenol resin solution comes into contact with the adsorbent, it is a binuclear body. Such low molecular weight substances cause osmotic diffusion through the pores to the inside of the particles. However, since molecules (medium molecular weight or high molecular weight) larger than the pore diameter cannot penetrate into the adsorbent particles, the adsorption to the adsorbent particles hardly occurs. In the production method of the present invention, the molecular sieve effect of the adsorbent is utilized, and only low molecular weight substances such as phenol resin dinuclear bodies are selectively separated and removed.

Next, the composition using the photoresist resin obtained by the present invention will be described.
Although it does not specifically limit as a composition of this invention, In addition to the said resin for photoresists, photosensitive agents, such as a quinonediazide group containing compound, can be contained. Moreover, it is preferable to use the solvent which melt | dissolves these, it melt | dissolves in this and uses it in the form of a solution.

Here, the quinonediazide group-containing compound is not particularly limited.
(1) 2,3,4-trihydroxybenzophenone, 2,4,4′-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,6-trihydroxybenzophenone, 2,3,4 Trihydroxy-2'-methylbenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,3', 4,4 ', 6-pentahydroxy Benzophenone, 2,2 ′, 3,4,4′-pentahydroxybenzophenone, 2,2 ′, 3,4,5-pentahydroxybenzophenone, 2,3 ′, 4,4 ′, 5 ′, 6-hexahydroxy Polyhydroxybenzophenones such as benzophenone, 2,3,3 ′, 4,4 ′, 5′-hexahydroxybenzophenone,
(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′-tri Hydroxyphenyl) propane, 4,4 ′-{1- [4- [2- (4-hydroxyphenyl) -2-propyl] phenyl] ethylidene} bisphenol, 3,3′-dimethyl- {1- [4- [ Bis [(poly) hydroxyphenyl] alkanes such as 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-hydroxyphenyl Methane, bis (4-hydroxy-3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2, Tris (hydroxyphenyl) methanes such as 5-dimethylphenyl) -3,4-dihydroxyphenylmethane and bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane or methyl-substituted products thereof,
(4) Bis (3-cyclohexyl-4-hydroxyphenyl) -3-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-4-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-Me Ruphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -2-hydroxy Phenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4) Bis (cyclohexylhydroxyphenyl) (hydroxyphenyl) methanes, such as -methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -4-hydroxyphenylmethane, or A complete ester compound of a methyl-substituted product and the like and a quinonediazide group-containing sulfonic acid such as naphthoquinone-1,2-diazide-5-sulfonic acid or naphthoquinone-1,2-diazide-4-sulfonic acid, orthoanthraquinonediazidesulfonic acid, Partial ester compounds, amidates or partial amidates,
And so on.

Here, the quinonediazide group-containing compound component may be contained singly or in combination of two or more. Moreover, this component is normally 5-100 weight part with respect to 100 weight part of said phenol resins, Preferably it can mix | blend in the range of 10-50 weight part.
If this content is less than the above lower limit value, it is difficult to obtain an image faithful to the pattern, and transferability may be lowered. On the other hand, when the above upper limit is exceeded, the sensitivity of the resist may be reduced.

Further, the solvent is not particularly limited. For example, ethylene glycol alkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol. Diethylene glycol dialkyl ethers such as dipropyl ether and diethylene glycol dibutyl ether, ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol Propylene glycol alkyl ether acetates such as nopropyl ether acetate, ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl amyl ketone, cyclic ethers such as dioxane, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate , Ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl oxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl formate, acetic acid Examples include esters such as ethyl, butyl acetate, methyl acetoacetate, and ethyl acetoacetate. These may be used alone or in combination of two or more.

Although the usage-amount of the said solvent is not specifically limited, It is preferable that the solid content concentration of a composition shall be 30 to 65 weight%. When the solid content concentration is less than the above lower limit value, the fluidity of the composition is lowered, so that the handling becomes difficult, and a uniform resist film is hardly obtained by the spin coating method. On the other hand, when the above upper limit is exceeded, applicability may decrease.
In addition to the above-described components, various additives such as a surfactant, an adhesion improver, and a dissolution accelerator may be used in this composition as necessary.

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

When the composition thus obtained is used as a photoresist, it is exposed through a mask so that a structural change occurs in the composition in the exposed portion, and the solubility in an alkali developer is increased. Promoted. On the other hand, low solubility in an alkaline developer is maintained in the non-exposed area. A resist function is imparted by the difference in solubility generated in this way.

Hereinafter, the present invention will be described by way of examples. However, the present invention is not limited to these examples. Further, “parts” and “%” described in Examples and Comparative Examples all indicate “parts by weight” and “% by weight”.

1. Synthesis of base resin (1) Synthesis example 1
Phenol in which m-cresol and p-cresol were mixed in a molar ratio (m-cresol / p-cresol) = 6/4 in a 3 L four-necked flask equipped with a stirrer, a thermometer, and a heat exchanger A 465 part of 37% formalin aqueous solution and 2 parts of oxalic acid were added to 1000 parts of a kind and reacted for 4 hours under reflux.
Thereafter, dehydration is carried out under normal pressure to an internal temperature of 170 ° C., and dehydration / demonomerization is further carried out to 200 ° C. under a reduced pressure of 70 torr to obtain 850 parts of a novolak type phenol resin having a weight average molecular weight of 4000 and a binuclear amount of 10%. This was designated as base resin A.

(2) Synthesis example 2
Phenol in which m-cresol and p-cresol were mixed in a molar ratio (m-cresol / p-cresol) = 3/7 in a 3 L four-necked flask equipped with a stirrer, thermometer and heat exchanger 435 parts of a 37% formalin aqueous solution and 2 parts of oxalic acid were added to 1000 parts of a kind, and reacted under reflux for 4 hours.
Thereafter, dehydration is carried out under normal pressure to an internal temperature of 170 ° C., and dehydration / demonomerization is further carried out to 200 ° C. under a reduced pressure of 70 torr to obtain 780 parts of a novolak type phenol resin having a weight average molecular weight of 3,500 and a binuclear amount of 12%. This was designated as base resin B.

(3) Synthesis example 3
Phenol in which m-cresol and p-cresol are mixed in a molar ratio (m-cresol / p-cresol) = 8/2 in a 3 L four-necked flask equipped with a stirrer, a thermometer, and a heat exchanger To 1000 parts of the compound, 443 parts of 37% formalin aqueous solution and 2 parts of oxalic acid were charged and reacted under reflux for 4 hours. Thereafter, dehydration is carried out under normal pressure to an internal temperature of 170 ° C., and dehydration / demonomerization is further carried out to 200 ° C. under a reduced pressure of 70 torr to obtain 720 parts of a novolak type phenol resin having a weight average molecular weight of 1500 and a dinuclear amount of 9%. This was designated as base resin C.

2. Synthesis of Resin for Photoresist (1) Example 1
A glass column having an inner diameter of 5 cm is filled with 300 parts of strongly basic ion exchange resin (IRA900 manufactured by Organo) as an adsorbent, and 300 parts of propylene glycol monomethyl ether acetate (hereinafter referred to as “PGMEA”) is added to the adsorbent. Affinity with. Thereto, 100 parts of base resin A dissolved in 300 parts of PGMEA was added, and the column was passed through while maintaining the inside of the column at 60 ° C. The solution after separation was dried with a vacuum dryer to obtain 95 parts of a resin A for photoresist. The weight average molecular weight measured by GPC was 5000, and the dinuclear mass was 3.4%.

(2) Example 2
In the same apparatus as in Example 1, 200 parts of a synthetic adsorbent (HP2MG manufactured by Mitsubishi Chemical Co., Ltd.) was charged as an adsorbent, and 200 parts of ethanol was added to make the adsorbent compatible. Thereto, 100 parts of base resin B dissolved in 300 parts of ethanol was added, and the column was passed through while maintaining the interior of the column at 60 ° C. The solution after fractionation was dried with a vacuum dryer to obtain 95 parts of a resin B for photoresist. The weight average molecular weight measured by GPC was 4000, and the dinuclear mass was 4.4%.

(3) Example 3
In the same apparatus as in Example 1, 300 parts of a synthetic adsorbent (Separbeads SP200 manufactured by Mitsubishi Chemical Corporation) was filled as an adsorbent, and 200 parts of ethyl acetate was added to make the adsorbent compatible. Thereto, 100 parts of base resin C dissolved in 300 parts of ethyl acetate was added, and the column was passed through while maintaining the inside of the column at 60 ° C. The separated solution was dried with a vacuum dryer to obtain 94 parts of a resin C for photoresist. The weight average molecular weight measured by GPC was 2500, and the dinuclear body weight was 3.9%.

3. Preparation of composition (1) Example 4
After 70 parts of the photoresist resin A obtained in Example 1 and 15 parts of 2,3,4-trihydroxybenzophenone ester of naphthoquinone 1,2-diazide-5-sulfonic acid were dissolved in 150 parts of PGMEA, the pore size was 1 Filtration was performed using a 0.0 μm membrane filter to prepare a positive photoresist composition.

(2) Example 5
A positive photoresist composition was prepared in the same manner as in Example 4 except that the photoresist resin B obtained in Example 2 was used instead of the photoresist resin A.

(3) Example 6
A positive photoresist composition was prepared in the same manner as in Example 4 except that the photoresist resin C obtained in Example 3 was used instead of the photoresist resin A.

(4) Comparative Example 1
A composition was prepared in the same manner as in Example 4 except that the base resin A obtained in Synthesis Example 1 was used instead of the photoresist resin A.

(5) Comparative Example 2
A composition was prepared in the same manner as in Example 4 except that the base resin B obtained in Synthesis Example 2 was used instead of the photoresist resin A.

(5) Comparative Example 3
A composition was prepared in the same manner as in Example 4 except that the base resin C obtained in Synthesis Example 3 was used instead of the photoresist resin A.

The characteristics evaluation shown below was performed using the compositions obtained in Examples 4 to 6 and Comparative Examples 1 to 3. The results are shown in Table 1.

4). Characteristic Evaluation Method (1) Sublimation Test Evaluation Method The 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. During this drying, the silicon wafer was covered with a petri dish to collect the sublimate. This operation was performed for 10 sheets, and the weight of the substance adhering to the petri dish was measured.
(2) Method for Measuring Film Loss Rate The composition was applied on a 3 inch silicon wafer with a spin coater so as to have a thickness of about 1 μm, and dried on a hot plate at 110 ° C. for 100 seconds. The wafer was immersed in a developing solution (2.38% tetramethylammonium hydroxide aqueous solution) for 60 seconds, washed with water, and dried on a hot plate at 110 ° C. for 100 seconds. The reduction amount of the film thickness when immersed in the developer is expressed as a percentage with respect to the film thickness before being immersed in the developer, and is defined as the film reduction rate.

Examples 1-3 are phenolic resins for photoresists obtained by the present invention.
And Examples 4-6 are the phenol resin compositions for photoresists of this invention using this resin for photoresists. In each of Examples 4 to 6, since a phenol resin having a small amount of binuclear substance was used, the amount of sublimation was small as compared with Comparative Examples 1 to 3 using a base resin not subjected to adsorption treatment. From this, it became clear that the phenolic resin for photoresist obtained by the present invention is suitable for photoresist for the purpose of LCD production.

  The production method of the present invention can efficiently produce a phenol resin for a photoresist having a low content of a binuclear component. Therefore, the photoresist composition using the phenolic resin for photoresist obtained by the production method of the present invention can reduce contamination of the production line and improve productivity, so that semiconductors such as IC and LSI can be used. It can be suitably used for manufacturing, manufacturing of display screen devices such as LCD, and manufacturing of printing original plates.

Claims (6)

The manufacturing method of the phenol resin for photoresists characterized by manufacturing by the following A process and B process.
Step A: Step of passing a phenol resin dissolved in an organic solvent through a column filled with an adsorbent; Step B: Step of reacting and / or concentrating the phenol resin after Step A. The method for producing a phenol resin for a photoresist according to claim 1, wherein the phenol resin synthesized by the step A and the step B satisfies the following characteristics.
1.2 Nucleotide component content is 5% or less of the whole resin.
2. The weight average molecular weight measured by GPC is 1000-20000. The phenol resin for photoresist according to claim 1 or 2, wherein the phenol resin used in the step A is synthesized from m-cresol, p-cresol and formaldehyde and satisfies the following characteristics. Method.
1. The charging weight ratio of m-cresol and p-cresol is m-cresol / p-cresol = 9/1 to 2/8.
2. The weight average molecular weight measured by GPC is 500-15000. The method for producing a phenol resin for a photoresist according to any one of claims 1 to 3, wherein the adsorbent used in the step A is an ion exchange resin or a synthetic adsorbent. 5. The method for producing a phenol resin for a photoresist according to claim 1, wherein the content of the adsorbent used in the step A is 10 to 500 parts by weight with respect to 100 parts by weight of the phenol resin. A photoresist resin composition comprising the photoresist resin according to any one of claims 1 to 5, a photosensitive agent, and a solvent.