JP2009075510A - Photoresist resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoresist phenolic resin composition which reduces the cost of photoresist and can enhance economic efficiency by using a low molecular weight novolac-type phenolic resin having a degree of dispersion in a relatively narrow range as an additive. <P>SOLUTION: The photoresist composition is characterized by addition of a novolac-type phenolic resin additive, wherein the novolac-type phenolic resin contains ortho-cresol as an essential component and has a degree of dispersion in a range of 1.5-2.5 and a weight average molecular weight of 500-3,000 as measured by GPC. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to 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 phenol 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.

On the other hand, in recent years, high integration of semiconductors has been increased, and various methods have been tried for thinning. As one of them, an additive is added to improve adhesion, heat resistance, photoresist modification, and the like (see, for example, Patent Document 1).
However, organic compounds such as phenol derivatives are mainly preferred for use as additives, and it is economical to use special phenol raw materials and catalysts, complicated purification steps, and washing steps when synthesizing them. Burden is large.
Japanese Patent Laid-Open No. 06-27655

  An object of the present invention is to provide a novolak type phenolic resin having ortho-cresol and para-cresol as monomer components and having a dispersity in the range of 1.5 to 2.5 as a resolution improver, an adhesion improver, and a modified photoresist. It is providing the resin composition for photoresists used as additives, such as a quality agent.

Such an object is achieved by the present invention (1) described below.
(1)
(A) With respect to 100 parts by weight of novolac-type phenolic resin not containing o-cresol as a raw material,
(B) A resin obtained by reacting phenol and formaldehyde comprising 10 to 50% by weight of o-cresol and 50 to 90% by weight of p-cresol in the presence of an acidic catalyst, and measured by GPC measurement. 1 to 10 parts by weight of an additive composed of a novolak type phenolic resin having a dispersity in the range of 1.5 to 2.5 and a weight average molecular weight of 500 to 3000,
(C) a photosensitive agent, and (D) a solvent,
Containing a resin composition for photoresist.

  According to the present invention, the function of the photoresist can be improved, and in particular, the remaining film property can be improved.

  Hereafter, each component used for the resin composition for photoresists of this invention is demonstrated.

The novolak-type phenol resin which does not contain (A) o-cresol used in the present invention will be described.
The phenols used in the novolak type phenolic resin that is the component (A) used in the present invention is not particularly limited as long as it is other than o-cresol. For example, cresols such as phenol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, xylenols such as 3,4-xylenol, 3,5-xylenol, o-ethylphenol, m-ethylphenol, In addition to ethylphenols such as p-ethylphenol, alkylphenols such as isopropylphenol, butylphenol and p-tert-butylphenol, polyhydric phenols such as resorcin, catechol, hydroquinone, pyrogallol and phloroglucin, alkylresorcins and alkylphenols Call (both alkyl groups, the carbon number is 1-4) alkyl polyhydric phenols such as alkyl hydroquinone. These can be used alone or in combination of two or more.

Among the above phenols, particularly preferred are m-cresol and p-cresol, and by using these phenols and adjusting the blending ratio of them, various properties such as sensitivity and heat resistance as a photoresist. Can be adjusted.
When m-cresol and p-cresol are used as the phenols, the ratio is not particularly limited, but the weight ratio (m-cresol / p-cresol) is preferably 9/1 to 2/8. More preferably, it is 8/2 to 4/6. 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.

  Although it does not specifically limit as aldehydes used for (A) component used for this invention, For example, formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxymethylene, chloral, hexamethylenetetramine, furfural, glyoxal, n -Butyraldehyde, caproaldehyde, allyl aldehyde, benzaldehyde, crotonaldehyde, acrolein, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde and the like. Among these, use of formaldehyde and paraformaldehyde is most preferable in view of characteristics.

Although it does not specifically limit as reaction molar ratio (F / P) of the said phenols (P) and aldehydes (F), It is preferable to set it as 0.5-1.0. Thereby, a phenol resin having a molecular weight preferable for use in a photoresist can be obtained.
When the reaction molar ratio exceeds the above upper limit, it may be excessively high molecular weight for use as a photoresist, or may be gelled depending on the reaction conditions.
Next, (B) a resin obtained by reacting phenols consisting of 10 to 100% by weight of o-cresol and 0 to 90% by weight of p-cresol with formaldehyde in the presence of an acidic catalyst. A novolak type phenol resin having a dispersity measured by GPC measurement in the range of 1.5 to 2.5 and a weight average molecular weight of 500 to 3000 will be described.
The novolak-type phenol resin used for the additive of the component (B) used in the present invention has o-cresol and p-cresol as monomer components, uses these phenols, and adjusts the blending ratio of both, Various characteristics such as a residual film as a photoresist, adhesion, sensitivity, and heat resistance can be adjusted.
In this case, the ratio of o-cresol to p-cresol is a weight ratio (o-cresol / p-cresol) = 10/90 to 50/50.

  As the aldehydes used in the novolac type phenol resin used as the additive of the component (B), it is preferable in terms of characteristics to use formaldehyde and paraformaldehyde.

  In the novolak type phenol resin used as the additive of the component (B), the content of unreacted phenols is not particularly limited, but it is preferably 3% by weight or less, preferably 2% by weight or less.

  (B) As for the molecular weight of the novolak type phenol resin used for the additive of component, the weight average molecular weight measured by GPC method is 500-3000, More preferably, it is 1000-2500. The degree of dispersion of the novolak type phenol resin used as the additive of the component (B) is 1.5 to 2.5, and preferably 1.5 to 2.0. When the weight average molecular weight exceeds the upper limit, there is a problem that the viscosity of the photoresist is increased. In addition, when the degree of dispersion exceeds the upper limit, there is a problem that the viscosity of the photoresist increases, and when the degree of dispersion is lower than the lower limit, the content of low molecular weight components increases, and there is a problem that heat resistance is deteriorated. .

Here, the content of unreacted phenols is measured by an internal standard method using 3,5-xylenol as an internal standard substance in accordance with JIS K 0114.
Further, the weight average molecular weight and the degree of dispersion are measured by gel permeation chromatography (GPC measurement). The weight average molecular weight and the degree of dispersion are calculated based on a calibration curve created using a polystyrene standard substance. GPC measurement is 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 apparatus is, for example: Main body: HLC-8020 manufactured by TOSOH
-Detector: UV-8011 manufactured by TOSOH Corporation set at a wavelength of 280 nm
-Column for analysis: Showa Denko Co., Ltd. * 1 SHODEX KF-802, 1 KF-803, 1 KF-805 are used.
The blending amount of the additive comprising the novolak type phenolic resin as the component (B) used in the present invention is 1 to 10 parts by weight with respect to 100 parts by weight of the novolak type phenolic resin as the component (A). Is used in small amounts as an additive.

Next, the (C) photosensitive agent used in the present invention will be described.
As the photosensitizer used in the present invention, for example, a quinonediazide group-containing compound can be used.
Examples of the quinonediazide group-containing compound include (1) 2,3,4-trihydroxybenzophenone, 2,4,4′-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,6-tri Hydroxybenzophenone, 2,3,4-trihydroxy-2′-methylbenzophenone, 2,3,4,4′-tetrahydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,3 ′, 4,4 ′, 6-pentahydroxybenzophenone, 2,2 ′, 3,4,4′-pentahydroxybenzophenone, 2,2 ′, 3,4,5-pentahydroxybenzophenone, 2,3 ′, 4,4 Polyhydroxybenzenes such as ', 5', 6-hexahydroxybenzophenone, 2,3,3 ', 4,4', 5'-hexahydroxybenzophenone Nzophenones,

(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) methane such as 5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, or a methyl-substituted product 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 Tilphenyl) -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) -Methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -4-hydroxyphenylmethane and the like, bis (cyclohexylhydroxyphenyl) (hydroxyphenyl) methanes Is a complete ester compound of a quinonediazide group-containing sulfonic acid such as naphthoquinone-1,2-diazido-5-sulfonic acid or naphthoquinone-1,2-diazide-4-sulfonic acid, orthoanthraquinonediazidesulfonic acid, etc. , Partial ester compounds, amidated products or partially amidated products.

  Here, the quinonediazide group-containing compound component may be contained singly or in combination of two or more.

In the resin composition of the present invention, the amount of the (C) photosensitizer is not particularly limited, but is usually 5 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the (A) novolak type phenol resin. It can mix | blend in the range of.
(C) When the blending amount of the photosensitive agent is less than the lower limit, it is difficult to obtain an image faithful to the pattern, and transferability may be deteriorated. On the other hand, when the upper limit is exceeded, the sensitivity of the photoresist may be reduced.

The (D) solvent will be described.
Examples of the solvent used in the resin composition of the present invention include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol alkyl ethers such as ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, Diethylene glycol dialkyl ethers such as diethylene glycol 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 monopropyl ether acetate, ketones such as acetone, methyl ethyl ketone, cyclohexanone and methyl amyl ketone, cyclic ethers such as dioxane, and methyl 2-hydroxypropionate and 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 individually by 1 type, and may be used in mixture of 2 or more types.

  Although the usage-amount of the said solvent is not specifically limited, It is preferable that the solid content concentration in a resin 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 it becomes difficult to handle and it is difficult to obtain a uniform resist film by the spin coating method.

  In addition to the above-described components, the resin composition of the present invention includes various novolaks such as a surfactant, an adhesion improver, and a dissolution accelerator in addition to fillers and pigments as necessary. Additives other than type phenol resins can also be used in combination.

Although it does not specifically limit as a preparation method of the resin composition of this invention, When a filler and a pigment are not added to a resin composition, the said (A)-(D) component is mixed and stirred by a normal method. Can be prepared.
Moreover, when adding a filler and a pigment, it can disperse | distribute and mix using dispersers, such as a dissolver, a homogenizer, and a 3 roll mill. Further, if necessary, the resin composition can be filtered using a mesh filter, a membrane filter or the like.

  By exposing the resin composition thus obtained through a mask, a structural change occurs in the resin composition in the exposed portion, and the solubility in an alkali developer is promoted. . On the other hand, low solubility in an alkaline developer is maintained in the non-exposed area. A resist function can be provided by the difference in solubility generated in this way.

  The novolak type phenolic resin used as the additive of the component (B) synthesized according to the present invention can be applied to various uses. For example, improvement of the residual film property of the photoresist, improvement of adhesion, modification, etc. It is expected that it can contribute to reducing the cost of the photoresist because it is a resin synthesized from an inexpensive raw material by providing functionality such as resolution improvement.

Hereinafter, the present invention will be described with reference to examples. However, the present invention is not limited to these examples. In the examples and comparative examples, “parts” indicates “parts by weight” and “%” indicates “% by weight”.
1. Synthesis of novolac type phenolic resin for additive (1) Example 1
Phenol in which o-cresol and p-cresol were mixed in a weight ratio (o-cresol: p-cresol) = 50: 50 in a 5 L four-necked flask equipped with a stirrer, a thermometer, and a heat exchanger. To 7000 parts of the class, 676 parts of a 37% formalin aqueous solution (reaction molar ratio F ₁ /P=0.9) and 10 parts of oxalic acid were charged, and the reaction was carried out under reflux conditions for 8 hours.
Thereafter, dehydration is performed under normal pressure up to an internal temperature of 170 ° C., and further, dehydration under reduced pressure is performed by raising the temperature to 200 ° C. under a reduced pressure of 8.0 kPa. 1050 parts of a 1.2% novolac type phenolic resin were obtained.

(2) Example 2
37% formalin aqueous solution 751 with respect to 1000 parts of phenols in which o-cresol and p-cresol were mixed in a weight ratio (o-cresol: p-cresol) = 25: 75 in the same apparatus as in Example 1. Parts (reaction molar ratio F ₁ /P=1.0) and 10 parts of oxalic acid were charged, and the reaction was carried out under reflux conditions for 8 hours.
Thereafter, dehydration is performed under normal pressure up to an internal temperature of 170 ° C., and further, dehydration under reduced pressure is performed by increasing the temperature to 200 ° C. under a reduced pressure of 8.0 kPa. The weight average molecular weight is 1500, the dispersity is 2.0, and unreacted phenols. As a result, 1030 parts of a 1.3% novolac type phenolic resin was obtained.

(3) Example 3
37% formalin aqueous solution 751 with respect to 1000 parts of phenols in which o-cresol and p-cresol were mixed in the same apparatus as in Example 1 at a weight ratio (o-cresol: p-cresol) = 10: 90. Parts (reaction molar ratio F1 / P = 1.0) and 10 parts of oxalic acid were charged, and the reaction was performed under reflux conditions for 12 hours.
Thereafter, dehydration is carried out under normal pressure up to an internal temperature of 170 ° C., and further, dehydration under reduced pressure is carried out by raising the temperature to 200 ° C. under a reduced pressure of 8.0 kPa. 1000 parts of 0.8% novolac type phenolic resin was obtained.

(1) Comparative Example 1
1000 parts of phenols and 465 parts of 37% formaldehyde aqueous solution prepared by mixing m-cresol and p-cresol in a molar ratio (m-cresol: p-cresol) = 40: 60 in the same apparatus as in Example 1. (F / P = 0.62), 21 parts of oxalic acid was charged, and the reaction was performed under reflux conditions for 4 hours.
Thereafter, dehydration is carried out under normal pressure up to an internal temperature of 170 ° C., followed by dehydration under reduced pressure by raising the temperature to 230 ° C. under a reduced pressure of 8.0 kPa, and a weight average molecular weight of 3500, a degree of dispersion of 4.0, unreacted phenols As a result, 730 parts of a 0.6% novolac-type phenol resin were obtained.

(2) Comparative Example 2
In the same apparatus as in Example 1, m-cresol and p-cresol were mixed at a molar ratio (m-cresol: p-cresol) = 80: 20: 1000 parts of phenol, 601 parts of 37% aqueous formaldehyde solution (F / P = 0.80), 8 parts of oxalic acid were charged, and the reaction was performed under reflux conditions for 4 hours.
Thereafter, dehydration is performed under normal pressure to an internal temperature of 170 ° C., and further, dehydration is performed by increasing the temperature to 220 ° C. under a reduced pressure of 6.7 kPa. The weight average molecular weight is 5200, the dispersity is 6.3, and unreacted phenols 840 parts of a 1.8% novolak type phenolic resin was obtained.

(2) Comparative Example 3
37% formalin aqueous solution 751 with respect to 1000 parts of phenols in which o-cresol and p-cresol were mixed in the same apparatus as in Example 1 in a weight ratio (o-cresol: p-cresol) = 75: 25. Parts (reaction molar ratio F ₁ /P=1.0) and 10 parts of oxalic acid were charged, and the reaction was carried out under reflux conditions for 8 hours.
Thereafter, dehydration is carried out under normal pressure up to an internal temperature of 170 ° C., and further, dehydration under reduced pressure is carried out by raising the temperature to 200 ° C. under a reduced pressure of 8.0 kPa. The weight average molecular weight 1950, the dispersity 1.9, unreacted phenols 1090 parts of 1.0% novolac type phenolic resin was obtained.

  Table 1 shows the results of the resin property evaluation of the novolac type phenol resins obtained in Examples 1 to 3 and Comparative Examples 1 to 3.

Preparation of phenolic resin composition for photoresist

(1) Example 4
7 parts of the novolak type phenolic resin for additive obtained in Example 1 and 70 parts of m / p cresol novolac type phenolic resin (resin having a weight average molecular weight of 5000 charged at a weight ratio of m / p = 50/50) After dissolving 15 parts of 2,3,4-trihydroxybenzophenone ester of naphthoquinone-1,2-diazide-5-sulfonic acid in 150 parts of PGMEA (propylene glycol monomethyl ether acetate), a membrane having a pore size of 1.0 μm Filtration using a filter gave a resin composition.

(2) Examples 5-6
Example 5 was the same as in Example 4 except that the novolac type phenol resin for additive obtained in Example 2 was used instead of the novolac type phenol resin obtained in Example 1. Got.
Similarly to Example 6, the same procedure as in Example 4 was used except that the novolac type phenol resin obtained in Examples 3 to 4 was used instead of the novolac type phenol resin obtained in Example 1. Thus, a resin composition was obtained.

(1) Comparative Example 4
A resin composition was obtained in the same manner as in Example 4 except that the novolak type phenol resin obtained in Comparative Example 1 was used instead of the novolak type phenol resin obtained in Example 1.

(2) Comparative Example 5
A resin composition was obtained in the same manner as in Example 4 except that the novolak type phenol resin obtained in Comparative Example 2 was used instead of the novolak type phenol resin obtained in Example 1.

(3) Comparative Example 6
A resin composition was obtained in the same manner as in Example 4 except that the novolak type phenol resin obtained in Comparative Example 3 was used instead of the novolak type phenol resin obtained in Example 1.

(3) Comparative Example 7
70 parts of m / p cresol novolac type phenolic resin (resin having a weight average molecular weight of 5000 charged at a weight ratio of m / p = 50/50) and 2,3 of naphthoquinone-1,2-diazide-5-sulfonic acid , 4-Trihydroxybenzophenone ester (15 parts) was dissolved in 150 parts of PGMEA (propylene glycol monomethyl ether acetate), followed by filtration using a membrane filter having a pore size of 1.0 μm to obtain a resin composition.

  The characteristics evaluation shown below was performed using the resin compositions obtained in Examples 4 to 6 and Comparative Examples 4 to 7. The results are shown in Table 2.

3. 3. Evaluation method of characteristics 3.1 Novolak type phenolic resin (1) yield It was calculated by the following formula.
Yield (%) = (weight of resin obtained / weight of charged phenolic monomer) × 100

(2) Content of Unreacted Phenols (Monomer) Based on JIS K 0114, it was measured by an internal standard method using 3,5-xylenol as an internal standard substance.

(3) Weight average molecular weight (Mw) and dispersity (Mw / Mn)
It measured by gel permeation chromatography (GPC measurement). The weight average molecular weight and the degree of dispersion were calculated based on a calibration curve prepared using a polystyrene standard substance. 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 device
-Body: manufactured by TOSOH-"HLC-8020"
・ Detector: TOSOH manufactured at a wavelength of 280 nm ・ “UV-8011”
・ Analytical column: Showa Denko Co., Ltd. “SHODEX KF-802 x 1, KF-803 x 1, KF-805 x 1”
It was used.

3.2 Phenolic resin composition for photoresist

(1) Film reduction rate The resin composition was coated on a 3 inch silicon wafer with a spin coater so as to have a thickness of about 1 μm, and dried on a 110 ° C. hot plate for 100 seconds. The wafer was immersed in a developing solution (2.38% tetramethylammonium hydroxide aqueous solution) for 60 seconds, washed with water, and dried on a hot plate at 110 ° C. for 100 seconds. The amount of decrease in film thickness when immersed in the developer was expressed as a percentage of the film thickness before being immersed in the developer. Accordingly, a film with a small film reduction rate indicates that the remaining film property is good.

(2) Alkali dissolution rate In the present invention, the alkali dissolution rate of the novolak resin is the time (seconds) that the coating film is completely dissolved when the Novoc resin coating film is immersed in a 2.38% tetramethylammonium hydroxide aqueous solution. The dissolution rate (Å / sec) determined from the relationship between the film thickness and the thickness (Å).

(3) Viscosity The viscosity of the resin composition was measured with an E-type viscometer. The viscosity after adding the novolak phenol resin for additives to the resin composition not containing the novolak phenol for additives was expressed as a percentage.

  Examples 4-6 are the phenol resin compositions for photoresists using the novolak-type phenol resin for additives obtained in Examples 1-3, and the viscosity of the photoresist is higher than that of Comparative Examples 4-7. The remaining film property could be improved without greatly changing.

  In the production method of the present invention, the phenol resin additive for photoresist using a low molecular weight novolak type phenol resin having a relatively narrow dispersibility is synthesized at low cost because it does not go through special raw materials, catalysts, or complicated purification steps. Therefore, it can contribute to the manufacture of semiconductors such as IC and LSI, the manufacture of display screen devices such as LCDs, and the manufacture of printing originals.

Claims (1)

(A) With respect to 100 parts by weight of novolac-type phenolic resin not containing o-cresol as a raw material,
(B) A resin obtained by reacting phenol and formaldehyde comprising 10 to 50% by weight of o-cresol and 50 to 90% by weight of p-cresol in the presence of an acidic catalyst, and measured by GPC measurement. 1 to 10 parts by weight of an additive composed of a novolak type phenolic resin having a dispersity in the range of 1.5 to 2.5 and a weight average molecular weight of 500 to 3000,
(C) a photosensitive agent, and (D) a solvent,
Containing a resin composition for photoresist.