JP2002258482A - Resin for photoresist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin excellent in transparency to the wavelength of light used for lithography and enabling the production of a photoresist having superior characteristics such as high sensitivity, high resolution, a high rate of a residual film, high heat resistance, a wide margin for focus and a wide margin for exposure. SOLUTION: The resin for a photoresist is represented by formula (I) (where R is an organic polymer, repeating units R may be the same or different; A is an organic group represented by -O- or -COO-; P is an organic group which can be released by the action of hydrogen or an acid; A and P may be the same or different every constitutional unit R; (l) is 1-20,000; (m) is 1-3 and may be the same or different every constitutional unit R; and (n) is 1-3 and the same number as (m)) and has alkali solubility promoted by the action of an acid. The resin is preferably derived from a phenolic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoresist resin used for lithography when manufacturing semiconductors and the like, and has excellent transparency, high sensitivity to light wavelengths used for lithography. High resolution, high residual film ratio, high heat resistance, wide focus margin, wide exposure margin
Enables production of photoresists with excellent features such as gin.

[0002]

2. Description of the Related Art In general, a positive photoresist is made of a photosensitive agent having a quinonediazide group such as a naphthoquinonediazide compound and an alkali-soluble resin (for example, a novolak phenol resin). Positive photoresists having such a composition exhibit high resolving power when developed with an alkaline solution, and are used for manufacturing semiconductors such as ICs and LSIs and LCDs.
It is used for the production of circuit substrates such as. In addition, novolak phenol resin also has high heat resistance to plasma dry etching after exposure due to the structure having many aromatic rings, and so far novolak phenol resin and naphthoquinonediazide type photosensitive Numerous positive-type photoresists containing have been developed and put into practical use, and have achieved great results.

Generally, a phenol resin obtained by reacting meta-paracresol and formaldehyde in the presence of an acid catalyst is used as a phenol resin for a photoresist. In order to adjust or improve the characteristics of photoresist, the ratio and molecular weight of meta-paracresol have been studied.
Technology has been applied. In semiconductor photoresists,
Characteristics such as high heat resistance, high resolution and high sensitivity are required, and to improve heat resistance, monomers such as alkylphenols such as xylenol and trimethylphenol and aromatic aldehydes have been studied. There is an example in which hydroxybenzaldehyde and the like have been studied for higher sensitivity. In each of these cases, although a slight improvement effect can be obtained, a sufficient effect has not yet been obtained.

In recent years, as the demand for higher integration of semiconductors has been increasing year by year, there has been a demand for resolution of a region which cannot be theoretically drawn with a wavelength of light such as g-line and i-line. Thus, light having a shorter wavelength has been applied as a light source. However, the amount of light of shorter wavelength generated from the light source is smaller than the amount of light such as g-line and i-line generated from a high-pressure mercury lamp, etc. A chemically amplified photoresist, which is a system utilizing the technology, has come to be applied. In addition, since the resin used uses light having a shorter wavelength, the novolak resin used for g-line and i-line is inferior in transparency due to absorption of light by the aromatic ring of itself. In addition, polyhydroxystyrene, acrylic resin and cycloolefin resin have come to be used. However, the transparency of polyhydroxystyrene is not sufficient, and it is very expensive. Therefore, the transparency of a low-cost phenolic resin system is improved, and the resin which exhibits high resolution and high sensitivity photoresist characteristics is improved. Development requirements are very high.

[0005]

The present invention relates to a resin for a photoresist used in lithography when manufacturing semiconductors and the like, and is excellent in transparency with respect to the wavelength of light used in lithography. Providing resins that enable the production of photoresists with excellent features such as sensitivity, high resolution, high residual film ratio, high heat resistance, wide focus margin, and wide exposure margin, especially polyhydroxystyrene It is an object of the present invention to achieve higher sensitivity than a photoresist using.

[0006]

The resin of the present invention is a resin for a photoresist whose alkali solubility is promoted by the action of an acid represented by the formula (I).

Embedded image

In the formula (I), R is an organic polymer, and any resin such as an addition polymerization resin such as vinyl polymerization or a polycondensation resin can be used. Particularly preferably,
Phenol resin, polyvinyl phenol resin, acrylic resin, cycloolefin resin and the like can be mentioned. The repeating units of R may be the same or different. A is an organic group represented by -O- or -COO-;
May be the same or different for each repeating unit.
P is an organic group which can be eliminated by the action of hydrogen or an acid;
May be the same or different for each structural unit. l is
It is particularly preferably from 1 to 20,000, more preferably from 10 to 10,000. If it is too small, the film formability will deteriorate, and if it is too large, the sensitivity will be low. m is 1 to 3 and may be the same or different for each structural unit of R. n is 1 to 3,
m.

In the case where R in the formula (I) is an organic group represented by the formula (II), a compound having particularly excellent characteristics of a photoresist can be obtained.

Embedded image In the formula (II), X is hydrogen, a hydroxyl group, an alkyl group having 1 to 8 carbon atoms, an alkenyl group and an alkoxy group, and halogen,
a = 0-3. Y is a divalent organic group, and is not particularly limited. Examples thereof include a methylene group and an ethylene group.

The method for obtaining the photoresist resin represented by the formula (I) is not particularly limited, but it is most effective to derive from a phenol resin from an economic point of view. Alternatively, a method of introducing an organic group which can be eliminated by the action of an acid can be used. First, the phenol resin used for obtaining the formula (I) will be described below. The phenol resin to be used can be obtained by reacting phenols and aldehydes in the presence of an acid and a base. First, the raw materials used will be described. Examples of phenols include phenol, meta-cresol, ortho-cresol, para-cresol, 2,
3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3 4-trimethylphenol, 2,3,5-trimethylphenol, 2,
3,6-trimethylphenol, 2,4,5-trimethylphenol, 3,4,5-trimethylphenol, ethylphenol, propylphenol, butylphenol
Octylphenol, nonylphenol, 1-naphthol, 2-naphthol, phenylphenol and the like can be used, but there is no particular limitation, and they may be used alone or as a mixture. From the viewpoint of high sensitivity,
, Orthocresol, 3,5-xylenol, 2,
3,5-Trimethylphenol is particularly preferred, and more preferably 90% or more of meta-cresol is used.

The aldehydes include formaldehyde,
Acetaldehyde, propylaldehyde, butyraldehyde and the like can be used without any particular limitation, and they may be used alone or in combination. Formaldehyde is particularly preferred from the viewpoint of high sensitivity. In the case of formaldehyde, formalin (aqueous solution), paraformaldehyde, alcohol
Any raw material can be used as long as it generates formaldehyde such as hemiformal and trioxane. Considering the price, it is preferable to use formalin and paraformaldehyde.

As the catalyst used for the reaction between phenols and aldehydes, an acid catalyst is generally used, and organic carboxylic acids such as oxalic acid and acetic acid, benzenesulfonic acid, paratoluenesulfonic acid, methanesulfonic acid and the like are used. Inorganic acid such as organic sulfonic acid, hydrochloric acid, sulfuric acid, etc. can be used, but there is no particular limitation, and it is also possible to use two or more kinds alone. In addition, a basic catalyst can also be used, and examples thereof include amines such as triethylamine and hydroxides such as sodium hydroxide and potassium hydroxide. The amount used is from 0.01% by weight to 5% by weight based on the phenols, but is preferably as small as possible in order to maintain the characteristics of the phenolic resin for photoresist. The reaction solvent can be used if necessary, but the type is not particularly limited. Any resin can be used as long as it dissolves the phenolic resin and lowers the viscosity of the resin obtained by the reaction. For example, ketones such as acetone and methyl ethyl ketone, ethanol
Alcohols such as butanol, esters such as ethyl acetate and butyl acetate, ether alcohols such as ethoxyethyl alcohol, ether esters of propylene glycol monomethyl ether acetate, etc. Is raised.

Further, the reaction (production) procedure of the phenol resin will be described. The reaction method described below is an example, and is not particularly limited thereto. The reaction is
Phenol in a reaction vessel equipped with a stirrer, thermometer and heat exchanger
And a catalyst such as aldehydes, aldehydes, acids or bases. The reaction temperature and time can be appropriately set depending on the reactivity of the above-mentioned reaction raw materials, but the reaction time is 2 to 10 hours and the reaction temperature is 70 to 150 ° C.
Is particularly preferred. If necessary, a reaction solvent can be used. The type of the solvent is not particularly limited, but a solvent that dissolves the phenol resin obtained by the reaction is particularly preferable.

After the completion of the reaction, if necessary, a neutralizing agent may be added to remove the acid and base catalysts to form a neutralized salt, and water may be added and washing may be performed. Although the amount and the number of times of the washing water are not particularly limited, the number of times of the washing is 1 from the viewpoint of economically removing the neutralized salt from the resin to a level that does not substantially affect the washing.
About -5 times is preferable. The washing temperature is not particularly limited, but may be 40 from the viewpoint of the efficiency of removing neutralized salts and workability.
It is preferably carried out at -95 ° C. During the washing, if the separation of the washing water from the resin is poor, it is effective to add a solvent or raise the washing temperature to reduce the viscosity of the resin. The type of solvent is not particularly limited, but any solvent can be used as long as it dissolves the phenol resin obtained by the reaction and lowers the viscosity.

After the completion of the reaction or washing with water, dehydration and de-monomerization are performed under normal pressure and reduced pressure to obtain a phenol resin for photoresist. The temperature at which the phenol resin is removed from the reaction vessel after the dehydration and demonomerization can be appropriately set depending on the characteristics of the phenol resin and the viscosity of the resin. In the case of the novolak resin, from 150 to 250 ° C. from the viewpoint of stability. It is particularly preferable to carry out the process, and in the case of a resole resin, it is preferable to take it out at 100 ° C. or lower. Although the degree of pressure reduction can be set as appropriate, it is particularly preferable to perform the pressure reduction at about 0.1 to 200 torr.

The weight average molecular weight of the phenolic resin for a photoresist which can be produced by the present invention is not particularly limited, but is preferably from 1,000 to 50,000 in view of the performance of the photoresist and the handling property in production. , 20
00 to 40,000 is more preferable, and still more preferably,
2500-30000. The most appropriate method for controlling the weight average molecular weight is to adjust the molar ratio of aldehydes to phenols, which can be appropriately set according to the target molecular weight.
From 1 to 2.5, more preferably 0.1 from the viewpoint of the weight average molecular weight, alkali solubility, heat resistance and the like of the obtained resin.
2-1.2. More preferably, 0.3-1.0
It is. In some cases, the phenotype obtained by the fractionation method utilizing the difference in solubility in various solvents and water is used.
There is also a method of adjusting the molecular weight and molecular weight distribution of the resin.
The material of the equipment such as a reaction vessel for the production is not particularly limited. However, from the viewpoint of contamination, impurities selected from glass lining, Teflon (registered trademark) or metals selected from tantalum, hafnium, zirconium, niobium, titanium and the like. It is preferable to use a manufacturing apparatus using a metal material made of an alloy and resistant to corrosion substantially containing no other material as a material of the reaction equipment.

Next, a method for introducing a group decomposable by the action of an acid will be described with reference to a phenol resin. The group substituted by the hydroxyl group of phenols and decomposable by an acid is not particularly limited, but may be any group as long as it is stable in the absence of an acid and easily decomposed by the action of an acid. An acetyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, and organic groups represented by the formulas (III) and (IV) can be mentioned.

Embedded image

Embedded image In the formula (III), Za is hydrogen, a methyl group, Zb is a methyl group, an ethyl group, Zc is an alkyl group having C = 1 to 8,
In formula (IV), Zd is an alkyl group or an alkenyl group having C = 1 to 8, but is not particularly limited, and may be the same or different. They may be the same or different. In particular,
C1-6 alkyl groups such as methyl group and butyl group, cycloalkyl groups such as cyclohexyl group, aryl groups such as dinitrophenyl group, aralkyl groups such as benzyl group, and fatty acids such as tetrahydropyranyl group and tetrahydrofuranyl group. Examples include acyl groups such as cyclic ether groups, acetyl groups, cyclohexylcarbonyl groups, and benzoyl groups; alkoxycarbonyl groups such as t-butoxycarbonyl groups; and alkoxyalkyl groups such as ethoxyethyl groups and isopropyloxyethyl groups. And t-butoxycarbonyl group, ethoxyethyl group and tetrahydropyranyl group are particularly preferred from the viewpoint of the sensitivity, resolution and heat resistance of the photoresist. The substitution rate of the phenolic hydroxyl group in the phenolic resin is preferably from 10 to 100%, particularly preferably from 25 to 90%. If the substitution ratio is too low, the transparency is deteriorated. If the substitution ratio is high, the transmittance of the photoresist is good, but the sensitivity of the photoresist may be reduced. The method for substituting a hydroxyl group in the phenol resin is not particularly limited because it differs depending on the group to be substituted.
In the case of a t-butoxycarbonyl group, a reaction method using di-tert-butoxydica-bonate in the presence of a basic compound, in the case of an ethoxyethyl group and a tetrahydropyranyl group, in the presence of an acidic catalyst , Ethyl vinyl ether and 3,4-dihydro-2H-pyran.

Next, a method for measuring an analysis value according to the present invention will be described. First, the weight average molecular weight of the resin will be described. The weight average molecular weight is determined by gel
It is calculated based on a calibration curve prepared by using a polystyrene standard material by measurement chromatography (GPC). The GPC measurement was performed using tetrahydrofuran as an elution solvent under the conditions of a flow rate of 1.0 ml / min and a column temperature of 40 ° C. Body: H made by TOSOH
LC-8020, detector: UV-8011, manufactured by TOSOH, set at a wavelength of 280 nm, analytical column: one SHOdex KF-802, KF-8031, manufactured by Showa Denko
And one KF-805.

The optical density (OD) was measured using a UV spectrophotometer (U-2000, manufactured by Hitachi, Ltd.) and a specific wavelength (248).
(nm) from the measured absorbance. The sample for evaluation was prepared by applying a resin solution dissolved in a solvent on a quartz glass by a spin coater and treating at 90 ° C. for 100 seconds to form a resin film on the quartz glass to a thickness of about 0.5 μm. Adjusted.

The substitution rate of the group decomposable by an acid is determined by a thermogravimetric analyzer (TG-DTA63 manufactured by Seiko-Denshi).
00), the substitution rate was calculated from the weight loss corresponding to each substituent from the obtained results. The TG-DTA measurement was performed at a heating rate of 10 ° C./min.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments.
All “parts” and “%” described herein indicate “parts by weight” and “% by weight”, and the present invention is not limited by these examples.

Example 1 Metacresol 1800 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 3716% formalin 1216 parts (aldehydes / phenols (F / P) = 0.90) and 9 g of oxalic acid
After conducting the reaction at 98-102 ° C for 4 hours, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C, and further dehydrated under reduced pressure to 200 ° C at 80 torr.
The monomer was removed to obtain 1850 g of a phenol resin.
The weight average molecular weight of the obtained resin was 8,500, and the free monomer was 1.5%.

Example 2 Metacresol 1800 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 1284 parts of 37% formalin (aldehydes / phenols (F / P) = 0.95) and 9 g of oxalic acid,
After conducting the reaction at 98-102 ° C for 4 hours, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C, and further dehydrated under reduced pressure to 200 ° C at 80 torr.
The monomer was removed to obtain 1900 g of a phenol resin.
The weight average molecular weight of the obtained resin was 38,000, and the free monomer was 1.2%.

Example 3 Metacresol 1800 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 371% formalin (1081 parts) (aldehydes / phenols (F / P) = 0.80) and 9 g of oxalic acid
After conducting the reaction at 98-102 ° C for 4 hours, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C, and further dehydrated under reduced pressure to 200 ° C at 80 torr.
The monomer was removed to obtain 1800 g of a phenol resin.
The weight average molecular weight of the obtained resin was 3,500, and the free monomer was 1.7%.

Example 4 Metacresol 1800 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 1243 parts of 37% formalin (aldehydes / phenols (F / P) = 0.92) and 9 g of oxalic acid,
After conducting the reaction at 98-102 ° C for 4 hours, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C, and further dehydrated under reduced pressure to 200 ° C at 80 torr.
The monomer was removed to obtain 1850 g of a phenol resin.
The weight average molecular weight of the obtained resin was 13,500, and the free monomer was 1.6%.

Example 5 Metacresol 1600 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 3,5-xylenol 200 parts, 37% formalin 1201 parts (aldehydes / phenols (F / P) =
0.90) and 9 g of oxalic acid, and reacted at 98-102 ° C. for 4 hours. Then, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C., and further 80 torr.
Dehydration and demonomerization were performed at 200 ° C. under reduced pressure to 200 ° C. to obtain 1850 g of a phenol resin. The weight average molecular weight of the obtained resin was 9,000, and the free monomer was 1.4%.

Example 6 Metacresol 1600 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Part, 2,3,5-trimethylphenol 200 g 37%
1188 parts of formalin (aldehydes / phenols (F / P) = 0.90) and 9 g of oxalic acid were charged, and 98-1
After reacting at 02 ° C. for 4 hours, ethyl cellosolve 65 was added.
After adding 0 parts, dehydration was performed under normal pressure to an internal temperature of 170 ° C., and dehydration and demonomerization were performed under reduced pressure at 200 torr at 80 torr to obtain 1850 g of a phenol resin. The weight average molecular weight of the obtained resin is 9000, and the free monomer is 1.
9%.

Example 7 Metacresol 1000 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Part, Orthocresol 800g 37% Formalin 121
6 parts (aldehydes / phenols (F / P) = 0.9
0), 9 g of oxalic acid was charged, and the reaction was carried out at 98-102 ° C. for 4 hours.
Dehydrate and remove the monomer under reduced pressure to 00 ° C,
Thus, 1850 g of resin was obtained. The weight average molecular weight of the obtained resin was 8,800, and the free monomer was 1.6%.

Example 8 Metacresol 600 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 3,5-xylenol 1200 g 37% formalin 1123 parts (aldehydes / phenols (F / P) =
0.90) and 9 g of oxalic acid, and reacted at 98-102 ° C. for 4 hours. Then, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C., and further 80 torr.
Dehydration and demonomerization were performed at 200 ° C. under reduced pressure to 200 ° C. to obtain 1850 g of a phenol resin. The weight average molecular weight of the obtained resin was 8,200, and the free monomer was 1.9%.

Example 9 Metacresol 900 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Part, 2,3,5-trimethylphenol 900 g 37%
1091 parts of formalin (aldehydes / phenols (F / P) = 0.90) and 9 g of oxalic acid were charged, and 98-1
After reacting at 02 ° C. for 4 hours, ethyl cellosolve 65 was added.
After adding 0 parts, dehydration was performed under normal pressure to an internal temperature of 170 ° C., and dehydration and demonomerization was performed at 80 torr under reduced pressure to 200 ° C. to obtain 1900 g of a phenol resin. The weight average molecular weight of the obtained resin was 8,600, and the free monomer was 1.
3%.

Table 1 shows the properties of the resins obtained in Examples 1 to 9.
Summarized in

[Table 1]

Next, a group capable of being eliminated by an acid was introduced into the phenol resin. << Examples 10 to 27 >> (1) In the case of tert-butoxycarbonyl group Di-tert-butyl-dica-bonate and triethylamine were added to the phenolic resin obtained in Examples 1 to 9 dissolved in tetrahydrofuran. After adding an appropriate amount and reacting at room temperature for 24 hours, diethyl ether was added. Further, ion-exchanged water was added thereto, and the resultant was washed with water three times, and the solvent was removed and dried to obtain a desired resin for a photoresist having a group removable by an acid. (2) In the case of an ethoxyethyl group and a tetrahydropyranyl group Ethyl vinyl ether and / or 3,3 were added to the phenolic resin obtained in Examples 1 to 9 dissolved in tetrahydrofuran.
An appropriate amount of 4-dihydro-2H-pyran was added, a catalytic amount of paratoluenesulfonic acid was added, and the mixture was reacted at room temperature for 4 hours. Thereafter, diethyl ether is added, ion-exchanged water is further added, and the resultant is washed three times with water, and the solvent is removed and dried to obtain a desired resin for a photoresist having a group removable by an acid. Was.

The reaction conditions of Examples 10 to 27 and the characteristic values of the obtained phenolic resin are summarized in Table 2.

[Table 2]

<< Evaluation Examples 1 to 18 >> Evaluation of Characteristics of Photoresist The phenol resin obtained in the example was dissolved in propylene glycol monomethyl ether acetate so as to have a resin concentration of 15%, and acid was exposed to light. A compound for generating resist characteristics (DAM-301 and TPS-105, manufactured by Midori Kagaku) was added in an appropriate amount to prepare a resist evaluation sample. The prepared sample was applied on a 5-inch silicon wafer using a spin coater, and 90
Prebaked at 60 DEG C. for 60 seconds. The rotation speed of the spin coater was adjusted so that the thickness of the applied sample became about 0.5 μm. After prebaking, UV manufactured by Lithotech Japan
Exposure was performed using ES-2000 while changing the exposure amount of light having a wavelength of 248 nm at several points, and the exposure was performed on a hot plate at 1
Post-baking was performed at 10 ° C. for 90 seconds. Thereafter, the film thickness of the exposed portion was measured by a film thickness measuring device, and development was performed using 2.38% tetramethylammonium hydroxide aqueous solution using RDA-790 manufactured by Lithotech Japan, and the amount of reduction in film thickness was measured. And the rate of decrease. Based on the measurement result,
Evaluation of tanθ of photoresist characteristic value, sensitivity (exposure amount) focal depth, limit resolution, pattern shape under conditions of 0.18 μm and L & S = 1/1 using simulation software of LeapSet and Prolith / 2 Was done.

Table 3 shows the compositions of the evaluation samples and the evaluation values of the resist properties.

[Table 3]

As is evident from these results, the photoresist resin obtained in the examples exhibits excellent photoresist properties when applied and used as a photoresist material.

[0036]

According to the present invention, a resin capable of producing a photoresist having high sensitivity and high resolution can be provided. The resin of the present invention is expected to contribute to the improvement of the semiconductor industry through improvement of the performance of photoresist. In addition, since it can be manufactured very simply and inexpensively, it seems to be useful for cost reduction.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA01 AA02 AB16 AC04 AC08 AD03 BE00 BE10 BG00 CB28 CB41 4J033 CA01 CA02 CA09 CA10 CA12 CB18 CB25 CC03 CC04 CC07 CC08 CC09 CC11 CC12 CC14 HA02 HA28 HB10

Claims (12)

[Claims] 1. A photoresist resin whose alkali solubility is promoted by the action of an acid represented by the formula (I). Embedded image (In the formula (I), R is an organic polymer, and the repeating units of R may be the same or different. A represents -O-,-
An organic group represented by COO—, P is an organic group that can be eliminated by the action of hydrogen or an acid. A and P may be the same or different for each structural unit of R. l is 1-2
0000 and m are 1 to 3 and may be the same or different for each structural unit of R. n is 1-3 and follows m. ) 2. The photoresist resin according to claim 1, wherein R in the formula (I) is an organic group represented by the formula (II). Embedded image (In the formula (II), X is hydrogen, a hydroxyl group, an alkyl group, an alkenyl group and an alkoxy group having C = 1 to 8, and halogen, and a = 0 to 3. Y is a divalent organic group. .) 3. The photoresist resin according to claim 1, wherein the optical density (OD) of the resin of the formula (I) is 1.0 or less. 4. The photoresist resin according to claim 1, wherein the resin of the formula (I) is derived from a phenol resin. 5. The photoresist resin according to claim 1, wherein the weight average molecular weight of the resin of the formula (I) obtained by GPC measurement is 1,000 to 50,000. 6. The photoresist resin according to claim 1, wherein the phenol resin used for deriving the formula (I) is synthesized by using methcresol as an essential component as phenols. . 7. The phenolic resin used to derive the formula (I) is a resin synthesized by using 90% or more of phenols with meta-cresol and using formaldehyde as aldehydes. The resin for a photoresist according to claim 1. 8. The phenolic resin used for deriving the formula (I) is ortho-cresol, meth-cresol,
At least one phenol selected from 3,5-xylenol and 2,3,5-trimethylphenol is 10 to 10;
The photoresist resin according to claim 1, wherein the resin is synthesized at 0% using formaldehyde as an aldehyde. 9. The phenol resin used for deriving the formula (I) has a weight average molecular weight obtained by GPC of 1,000 to 50,000 and an optical density (OD) of 1.0 or less. Photoresist resin. 10. The method according to claim 1, wherein P in the formula (I) is hydrogen, a tetrahydropyranyl group, a tetrahydrofuranyl group, an acetyl group or any one or more of the general formulas (III) and (IV). Resin for photoresist. Embedded image Embedded image (In the formula (III), Za is hydrogen, a methyl group, Zb is
A methyl group, an ethyl group, and Zc are an alkyl group and an alkenyl group having C = 1 to 8. In the formula (IV), Zd is C =
1 to 8 alkyl groups and alkenyl groups. ) 11. The photoresist resin according to claim 1, wherein the proportion of P in the formula (I) other than hydrogen is 10 to 100%. 12. P in the formula (I) other than hydrogen is ter
The photoresist resin according to claim 1, wherein the resin is at least one of a t-butoxycarbonyl group, an ethoxyethyl group, and a tetrahydropyranyl group.