JP2003261657A - Polymer for chemical amplification type photoresist, photoresist composition and process for producing semiconductor device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer for a chemical amplification type photoresist that is suitable for an ArF excimer light and provide a photoresist composition. <P>SOLUTION: The polymer for a chemical amplification type photoresist comprises a structural unit represented by formula (I) and has a weight average molecular weight of 2,000-100,000 as determined by the GPC measurement. In formula (I), X is one kind or more selected from a 3-15C aliphatic alkyl group, a monocyclic alkyl group, a cyclic ether group, a cyclic ester group and a 6-15C polycyclic alkyl group wherein X is bonded through a tertiary carbon thereof to an ester group. One or more hydrogen atoms in any of X may be substituted by a 1-15C alkyl group, an alkoxy group, a carboxyl group, an ether group, a 3-15C cyclic alkyl group, a cyclic alkoxy group or a halogen atom. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polymer for a chemically amplified photoresist, a photoresist composition, and a method for producing a semiconductor.

[0002]

2. Description of the Related Art In general, a positive photoresist uses a sensitizer having a quinonediazide group such as a naphthoquinonediazide compound and an alkali-soluble resin (for example, a novolak phenolic resin). The positive photoresist having such a composition exhibits high resolution when developed with an alkaline solution, and is used for manufacturing semiconductors such as IC and LSI and circuit substrates such as LCD. Further, because of the structure having many aromatic rings, the novolac type phenol resin has high dry etching resistance and heat resistance against plasma dry etching after exposure. Up to now, many positive photoresists containing a novolac phenolic resin and a naphthoquinonediazide-based photosensitizer have been developed and put into practical use, and great results have been achieved in line width processing up to about 0.3 to 2 μm.

However, in recent years, as the demand for higher integration of semiconductors has increased year by year, finer line widths have been required to be processed, and the use of excimer light such as KrF, ArF, F _{2 having} a shorter wavelength as a light source has been considered. Has been done. These lights are lights having wavelengths of 248 nm, 193 nm, and 157 nm, respectively. However, the phenol resin has poor transparency due to absorption of light by the aromatic ring of itself, and the light does not easily reach the bottom of the resist. Therefore, the exposure amount at the bottom of the resist was insufficient, and only a defective pattern with a taper or the like was obtained after development. Therefore, polyhydroxystyrene for KrF, acrylic resin, cycloolefin resin for ArF, and fluorine resin for F ₂ are used as the base resin, and the acid generated from the photoacid generator is used as a catalyst. Amplification systems are being considered for application.

For the KrF excimer light, application of polyhydroxystyrene has been mainly studied, and its practical application has already been advanced. However, studies are underway to further increase the degree of integration of semiconductors, and ArF with a shorter wavelength is being used.
It was necessary to apply excimer light. In that case, polyhydroxystyrene cannot be used because of insufficient transparency, and application studies of acrylic resins, cycloolefin resins, and the like are being advanced. The main required characteristics of the photoresist for ArF excimer light are high transparency and dry etching resistance in the ArF wavelength (193 nm) region. Difference in dissolution rate between exposed and unexposed areas in an alkaline developer (= dissolution contrast). The adhesion is large with respect to the heat resistant substrate. Acrylic resins have sufficient transparency, but are insufficient in dry etching resistance and heat resistance, and although cycloolefin resin norbornene / maleic anhydride resin can achieve dry etching resistance, transparency, The drawback is that the resolution and adhesion are poor, and there are advantages and disadvantages at present.

As described above, the conventional positive-working chemically amplified photoresist polymer has a protecting group in its side chain, and exhibits a property of dissolving in a developing solution when it is eliminated by an acid. Therefore, although the characteristics can be finely adjusted by selecting the type of the protecting group, basically the structure and physical properties of the main chain dominate the characteristics of the photoresist. That is, the acrylic resin is inferior in dry etching resistance because the main chain is an alkyl group. Further, in the norbornene / maleic anhydride resin which is a cycloolefin resin, since the main chain is a cycloalkyl group, the polarity of the resin itself is lowered, and the dissolution contrast and the adhesiveness are deteriorated. In order to solve these problems, there is an example in which an acrylic resin and a cycloolefin resin are mixed and applied, but a photoresist satisfying all the required characteristics has not been developed yet.

[0006]

SUMMARY OF THE INVENTION The present invention provides the following
The present invention provides a polymer for a chemically amplified photoresist that satisfies the above-mentioned required characteristics and is particularly suitable for ArF excimer light, a photoresist composition, and a method for producing a semiconductor using the same.

[0007]

Such an object is achieved by the present invention described in (1) to (4) below. (1) Comprising a structural unit represented by the general formula (I), GP
Weight average molecular weight measured by C is 2000 to 100,000
Is a chemically amplified polymer for photoresists.

[Chemical 3] In the general formula (I), X is 1 selected from an aliphatic alkyl group having 3 to 15 carbon atoms, a monocyclic alkyl group, a cyclic ether group, a cyclic ester group, and a polycyclic alkyl group having 6 to 15 carbon atoms. It is more than one kind and is bonded to the ester group through a tertiary carbon. One or more hydrogen atoms of X are substituted with an alkyl group having 1 to 15 carbon atoms, an alkoxy group, a carboxyl group, an ether group, a cyclic alkyl group having 3 to 15 carbon atoms, a cyclic alkoxy group, or a halogen atom. It may have been done. (2) X in the general formula (I) is the chemical formula (II),
The polymer for chemically amplified photoresist according to (1) above, which is one or more kinds selected from (III) and (IV).

[Chemical 4] (3) A chemically amplified photoresist composition containing the following (X) to (Z) as essential components. (X) Dissolves the chemically amplified photoresist polymer described in (1) or (2) above, (Y) a compound that generates an acid by the action of light, and (Z) (X) and (Y). solvent. (4) A method for producing a semiconductor, which comprises using the chemically amplified photoresist composition described in (3) above and using an ArF excimer laser as an exposure light source.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a polymer for a chemically amplified photoresist, a chemically amplified photoresist composition, and a method for producing a semiconductor using the same.
The chemically amplified photoresist polymer of the present invention comprises the structural unit represented by the general formula (I), and has a weight average molecular weight of 2000 to 100000 as measured by GPC. Further, the chemically amplified photoresist composition of the present invention contains the above chemically amplified photoresist polymer, a compound that generates an acid by the action of light, and a solvent that dissolves these as essential components. The method for producing a semiconductor of the present invention is characterized by using the chemically amplified photoresist composition and using an ArF excimer laser as an exposure light source. First, the polymer for chemically amplified photoresist of the present invention (hereinafter referred to as “polymer”) will be described.

(X) Polymer The polymer of the present invention has a structure in which a group represented by X is bonded to a tertiary carbon with a dicarboxylic acid ester of adamantane as represented by the general formula (I). Is.
In the general formula (I), X is 1 selected from an aliphatic alkyl group having 3 to 15 carbon atoms, a monocyclic alkyl group, a cyclic ether group, a cyclic ester group, and a polycyclic alkyl group having 6 to 15 carbon atoms. It is more than one kind and is bonded to the ester group through a tertiary carbon. One or more hydrogen atoms of X are substituted with an alkyl group having 1 to 15 carbon atoms, an alkoxy group, a carboxyl group, an ether group, a cyclic alkyl group having 3 to 15 carbon atoms, a cyclic alkoxy group, or a halogen atom. It may have been done. The polymer represented by the general formula (I) is
By having an adamantane skeleton, it is possible to improve heat resistance and dry etching resistance while maintaining transparency with respect to the exposure light source. Further, X is a group bonded to a dicarboxylic acid ester of adamantane through a tertiary carbon. As a result, the hydrolyzability with respect to acid is improved, and the sensitivity and resolution can be improved. When the bonded carbon is a primary or secondary carbon, it exhibits hydrolysis resistance to the generated acid, and its solubility in a developing solution decreases, which may result in a decrease in resolution. The type of X is not particularly limited as long as it is within the above-mentioned range and can be selected and used for the desired characteristics, but one selected from the chemical formulas (II), (III) and (IV) The above is preferable. As described above, when a cyclic compound having a large number of carbon atoms is used, dry etching resistance and solubility in a solvent can be improved. Further, by using as the X, one having a polar substituent such as an alkoxy group, a carboxyl group, or a cyclic alkoxy group, it is possible to improve the substrate adhesion. further,
The transparency can be improved by introducing halogen such as fluorine as a substituent.

The weight average molecular weight of the polymer of the present invention is 2000 to 100,000. If the weight average molecular weight is less than 2000, the heat resistance may decrease, and 1
If it exceeds 00000, the sensitivity of the polymer may decrease. The weight average molecular weight of the polymer of the present invention can be controlled by changing the monomer concentration, the polymerization initiator concentration, the reaction temperature, etc. when synthesizing the polymer. The weight average molecular weight is preferably 3,000 to 80,000. The weight average molecular weight is calculated based on a calibration curve prepared using a polystyrene standard substance by gel permeation chromatography (GPC) measurement. GPC measurement uses tetrahydrofuran as an elution solvent, a flow rate of 1.0 ml / min, and a column temperature of 40
It was carried out under the condition of ° C. Body: TOSOH HLC-80
20, detector: TOSOH set to a wavelength of 280 nm
UV-8011, Analytical column: Showa Denko SHOD
EX KF-802 1 piece, KF-803 1 piece, KF-
One 805 was used.

The polymer of the present invention is not particularly limited,
It can be synthesized by a general ester polymerization reaction by condensation of dicarboxylic acid and diol. First, the raw materials used for the synthesis will be described. In the general formula (I),
The dialcohol compound used with 1,3-adamantanedicarboxylic acid is not particularly limited as long as it corresponds to the structure of the group X described above, but for example, 1,3-
Adamantane diol, 1,4-bis (2-hydroxypropyl) cyclohexane, 1,3-bis (2-hydroxypropyl) cyclohexane, 1-fluoro-2,5
-Bis (2-hydroxypropyl) cyclohexane,
Examples include 1,4-dihydroxynorbornene and methoxycyclohexanediol.

The conditions for synthesizing the polymer of the present invention are not particularly limited, but they are synthesized by a general ester polymerization reaction. That is, a polymer can be obtained by charging equimolar amounts of the carboxyl group component of the dicarboxylic acid and the hydroxyl group component of the diol and dehydrating and condensing with a small amount of acid as a catalyst. Further, in this synthetic reaction, a solvent can be used if necessary. The solvent is not particularly limited as long as it does not inhibit the reaction such as deactivating the acid. For example, tetrahydrofuran (TH
F), dimethylformamide (DMF), dimethylsulfoxide (DMSO), toluene, propylene glycol monomethyl ether acetate (PGMEA), cyclohexanone and the like can be used. It is difficult to react 100% of the monomers charged at the time of the reaction, but the residual monomer can be removed by performing a purification operation such as reprecipitation or dialysis. Further, it is more preferable as a polymer for a chemically amplified photoresist to remove metal impurities and the like through a column such as an ion exchange resin, if necessary.

Next, the chemically amplified photoresist composition of the present invention (hereinafter referred to as "composition") will be described.
The composition of the present invention is the polymer of the present invention, a compound that generates an acid by the action of light (hereinafter, referred to as “photo-acid generator”),
And a solvent that dissolves the polymer and the photo-acid generator (hereinafter,
"Solvent") is added as an essential component. When the composition of the present invention is used as a photoresist, the photoacid generator generates an acid upon irradiation with light, and the action of this acid causes a decomposition reaction in the polymer skeleton. Specifically, the polymer is decomposed at the carboxylic acid ester bond site in the general formula (I). The polymer in the portion where the decomposition reaction has occurred is dissolved in an alkaline developer in the subsequent development step, and a clear difference in the dissolution rate is produced between the polymer in the portion where the decomposition reaction has not occurred and the target pattern is formed. It can be obtained by development.

(Y) Photo-acid generator The photo-acid generator used in the composition of the present invention is not particularly limited, but includes a sulfonium salt derivative [sulfonic acid ester (1,2,3-tri (methylsulfonyloxy) benzene]. Aryl alkane sulfonates such as C
_6-10 aryl C _1-2 alkane sulfonates); 2,6
Dinitrobenzyltoluene sulfonate, benzoin tosylate nadnoarylbenzene sulfonate (particularly C _6-10 aryltoluene phosphonate optionally having a benzoyl group); 2-benzoyl-2-hydroxy-2
Aralkylbenzene sulfonates such as phenylethyltoluene sulfonate (especially C _6-10 aryl-C _1-4 alkyltoluene sulfonate _optionally having a benzoyl group); disulfonic acid such as diphenyldisulfone; Lewis acid salt (triphenyl Sulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimony, triphenylsulfonium methanesulfonyl and other triarylsulfonium salts (especially triphenylsulfonium salts), etc.)], phosphonium salt derivatives, diarylhalonium salt derivatives [diaryliodonium salts ( Lewis acid salts such as diphenyliodonium hexafluorophosphate, etc.], diazonium salt derivatives (p-nitrophenyldiazonium hexafluorophosphate, etc.) Lewis, etc. salts), such as, diazomethane derivatives, triazine derivatives can be exemplified. In particular, Lewis acid salts (Lewis acid salts such as phosphonium salts) are preferable.

In the composition of the present invention, the amount of the photoacid generator is not particularly limited, but it is preferably 1 to 20 parts by weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymer. It is a department. This improves the sensitivity and resolution of the composition. If the blending amount of the photo-acid generator is less than the above lower limit value, the deprotection reaction of the polymer is difficult to proceed, so that an image may not be formed. On the other hand, if the upper limit is exceeded, the deprotection reaction will proceed rapidly, and the polymer will be more likely to dissolve during development, making it difficult to form an image or lowering the melting point to lower the heat resistance. May become.

(Z) Solvent The solvent to be added to the composition of the present invention is not particularly limited as long as it dissolves the polymer and the photo-acid generator, and examples thereof include water, alcohols, glycols and cellosolve. Kinds, ketones, esters, ethers, amides #,
Examples thereof include organic solvents such as hydrocarbons, specifically, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, ethyl cellosolve acetate, methyl cellosolve acetate, butyl cellosolve acetate, methoxyethyl propionate. , Ethoxyethyl propionate, methyl lactate, ethyl lactate, butyl lactate,
Examples thereof include ethyl acetate, butyl acetate, methyl isobutyl ketone and methyl pentyl ketone. Among these, PGMEA, ethoxyethyl propionate, and ethyl lactate are particularly preferable from the viewpoints of solubility, coating film stability, safety, environmental impact, human impact, and economic efficiency. These may be used alone or in combination of two or more.

In the preparation of the composition of the present invention, if necessary, various additives such as a stabilizer such as an antioxidant, a plasticizer, a surfactant, an adhesion improver and a dissolution accelerator may be used. Good.

The method for producing the composition of the present invention will be described below. First, (X) polymer and (Y) photo-acid generator are dissolved in (Z) solvent. At that time, if necessary, a stabilizer such as an antioxidant, a plasticizer, a surfactant, an adhesion improver,
Various additives such as a dissolution accelerator may be added. The above components can be dissolved in any order. Normal,
Under a temperature condition of about room temperature, the components are dissolved by stirring for a time sufficient to dissolve each component (for example, 6 to 12 hours). After dissolution, filter (PT with filtration accuracy of 0.1 μm or less
Foreign substances are removed using an FE (polytetrafluoroethylene) filter or the like), and the container is filled with the foreign substances and metal impurities. It is preferable that the work is performed in a clean room of class 100 or less, and an automatic filling device that does not involve humans is used. Further, at an appropriate stage during manufacturing, it is possible to perform washing with an acid aqueous solution or pure water or demetallization with an ion exchange resin in order to remove metal impurities as necessary.

Next, the method for manufacturing a semiconductor of the present invention (hereinafter, referred to as
"Manufacturing method") will be described. The production method of the present invention is characterized by using the composition and using an ArF excimer laser as an exposure light source. As an example of the manufacturing method of the present invention, first, a silicon wafer, metal, plastic, glass, ceramic, or the like is used as the base material or the substrate. The composition of the present invention is usually applied to these substrates or substrates using a spin coater, a dip coater, a roller coater, or the like. The thickness of the coating film is, for example, 0.1 to 20 μm, preferably 0.3 to 2 μm.
It is about m. The composition after coating is, for example, 80 to 100.
Prebaking is performed at 1 ° C for 1 to several minutes to form a film. Next, ArF
Exposure is performed using excimer laser light using a predetermined mask pattern. The exposure energy is, for example, 0.5 to
500 mJ / cm ² , preferably 1-100 mJ / cm ²
It is a degree. As a result, an acid is generated from the photoacid generator in the light-irradiated portion, and the acid hydrolyzes the ester group portion of the polymer of the present invention to generate a carboxyl group that contributes to solubilization. After exposure, 1 ~ 100 ~ 160 ℃
A positive resist pattern can be obtained by performing a post-exposure bake (PEB) for several minutes, and performing paddle development with an alkali solution such as an aqueous solution of tetramethylammonium hydroxide, washing with water, and drying.

[0020]

EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited thereto.

1. Polymer Synthesis <Example 1> 1 equipped with mechanical stirrer and cooling tube
In a 00 ml three-necked flask, raw material monomers (1,3-
11.2 g (0.05 mol) of adamantane dicarboxylic acid and 8.9 g (0.0 of 1,3-adamantanediol)
5 mol)), paratoluenesulfonic acid (monohydrate) (P
0.02 g (0.0001 mol) of TSA and 30.5 g of tetrahydrofuran (THF) as a reaction solvent were added and dissolved. The inside of the flask was set to a reduced pressure condition of 80 torr, and the contents of the flask were heated to 140 ° C. using an oil bath. After reaching 140 ° C., the temperature was kept for about 6 hours to carry out a polymerization reaction. After the reaction was completed, the reaction solution was gradually poured into a large amount of methanol to precipitate the produced polymer. The supernatant was removed by decantation and the precipitate was taken out. The precipitate was vacuum dried at 40 ° C. overnight to obtain a polymer having a polystyrene-equivalent weight average molecular weight of 7,500 measured by GPC.

<Example 2> 1,3 as raw material monomers
GADA was carried out in the same manner as in Example 1 except that 13.3 g (0.06 mol) of adamantanedicarboxylic acid and 12.0 g (0.06 mol) of 1,4-bis (2-hydroxypropyl) cyclohexane were used. A polymer having a polystyrene-equivalent weight average molecular weight of 6000 was obtained by measurement.

<Example 3> 1,3 as raw material monomers
-Adamantanedicarboxylic acid 8.9 g (0.04 mol), 1,4-dihydroxynorbornene 5.5 g
A polymer having a polystyrene-equivalent weight average molecular weight of 7,200 by GPC measurement was obtained in the same manner as in Example 1 except that (0.04 mol) was used.

Comparative Example 1 In a 200 ml three-necked flask equipped with a mechanical stirrer and a cooling tube, 10.5 g of norbornyl methacrylate and 5.2 of methacrylic acid were added.
g, 1.0 g of azoisobutyronitrile, and 100 g of tetrahydrofuran were charged and reacted at 70 ° C. for 8 hours. After completion of the reaction, the product was reprecipitated with n-hexane, and the polystyrene-reduced weight average molecular weight by GPC measurement was 8000.
A polymer of

Comparative Example 2 A 200 ml three-necked flask equipped with a mechanical stirrer and a cooling tube was charged with 8-methoxy-carbonyltetracyclo [4.4.0.1 ^2,5 . 1
^7,10 ] dodeca-3-ene (53.0 g), maleic anhydride (24.5 g), azoisobutyronitrile (2.0 g) and tetrahydrofuran (40.0 g) were charged at 80 ° C for 10
Reacted for hours. After completion of the reaction, reprecipitation was performed using n-hexane to obtain a polymer having a polystyrene-equivalent weight average molecular weight of 5000 by GPC measurement.

2. Preparation of Compositions (Examples 4 to 6, Comparative Examples 3 to 4) 10 parts by weight of the polymer obtained in each of the Examples and Comparative Examples was used.
After being dissolved in 0 part by weight of propylene glycol monomethyl ether acetate (PGMEA), 0.2 parts by weight of triphenylsulfonium triflate as a photo-acid generator was added and sufficiently dissolved, and then the filtration accuracy was 0.1 μm.
It filtered using the filter made from PTFE of No. 3, and the composition was obtained.

3. Evaluation of Photoresist Performance 1) Sensitivity The composition prepared was applied onto a silicon wafer by a spin coater so that the film thickness after prebaking would be 0.5 μm, and then prebaked at 90 ° C. for 60 seconds on a hot plate. After that, ArF excimer laser irradiation device (lens numerical aperture 0.60, exposure wavelength 193n, manufactured by ISI)
m) test reticle (mask) with various line widths
Exposed through. Then 140 on the hot plate
After a post-exposure bake (PEB) at 90 ° C. for 90 seconds, 2.
Paddle development was performed for 60 seconds at 23 ° C. with a 38 wt% tetramethylammonium hydroxide aqueous solution.
Then, it was washed with water and dried to obtain a positive pattern. that time,
The sensitivity was defined as the exposure amount for forming a line-and-space pattern having a line width of 0.18 μm (the ratio of line to space was 1: 1) with a line width of 1: 1. 2) The resolution is defined as the minimum size of the photoresist pattern that is resolved when exposed with an exposure amount corresponding to the sensitivity of resolution 1). 3) A thin film having a thickness of 0.7 μm was formed by the same procedure as the etching rate 1). This was placed in an etching chamber of a parallel plate type dry etching apparatus, and an etching experiment using fluorine-based gas plasma was conducted. For the etching, CF ₄ gas and O ₂ gas are used for CF ₄ / O ₂ = 85 sccm / 15 sccm (scc
m: Standard cc / min (indicating the flow rate per minute at a constant temperature)), and the pressure in the etching chamber was 5 Pa. In addition, the power density is 0.
Performed under the condition of 12 W / cm ² and measured value is Å / min
It was written with. 4) Heat resistance After forming a resist pattern of a positive photoresist composition as described in 1) above, this is heated for 1 minute at 140 ° C. using a hot plate, and the shape change of the pattern profile is observed by a scanning electron microscope. It was observed with, and those that did not change were evaluated as ◯, and those that changed were evaluated as x. 5) Adhesiveness The peeling state of the pattern was confirmed using a side scanning electron microscope. The case where no peeling was observed was regarded as good.

The measurement results of 1) to 5) are shown in Table 1.

[Table 1]

Examples 1 to 3 are polymers for photoresists having a structural unit represented by the general formula (I) and having a weight average molecular weight of 2000 to 100000 as measured by GPC. In addition, Examples 4 to 6 are photoresist compositions using the same. In all of these, the composition of Comparative Example 4 using the polymer of Comparative Example 2 (cycloolefin type) while maintaining the sensitivity and resolution of the composition of Comparative Example 3 using the polymer of Comparative Example 1 (acrylic type). Since the heat resistance and dry etching resistance of the product were satisfied, the respective disadvantages could be improved and the properties could be made compatible without impairing the advantages of both.

[0030]

The photoresist polymer of the present invention is
It is composed of a structural unit represented by the general formula (I), and has a weight average molecular weight of 2000 to 100000 as measured by GPC. The polymer has an adamantyl skeleton in the main chain, thereby improving dry etching resistance, heat resistance, and transparency when used as a photoresist composition, and further decomposed by the action of an acid to give an alkaline developer. The sensitivity and resolution are improved by introducing an ester skeleton exhibiting solubility in water. By using this polymer together with a photo-acid generator, a solvent, etc., especially in the case of using ArF excimer light as a light source, high transparency in the ArF wavelength (193 nm) region, dry etching resistance, and alkaline development of exposed and unexposed areas A large difference in dissolution rate (= dissolution contrast) in a liquid can provide a chemically amplified photoresist composition that simultaneously satisfies required properties such as adhesion to a heat resistant substrate.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H025 AA01 AA02 AA09 AA10 AA14                       AB16 AC08 AD03 BE00 BG00                 4J029 AA03 AB01 AC01 AC02 AD01                       AE11 AE18 BD02 BD03C                       BD06A BD06C BD10 BG17Y                       CD07 HA01 HB01 JB043                       JB183 JB233 JC123 JC353                       KB02 KC01 KE03

Claims (4)

[Claims] 1. A structural unit represented by the general formula (I), having a weight average molecular weight of 2000 to 10 as measured by GPC.
Polymer for chemically amplified photoresist of 0000. [Chemical 1] In the general formula (I), X represents an aliphatic alkyl group having 3 to 15 carbon atoms, a monocyclic alkyl group, a cyclic ether group, a cyclic ester group, and 6 to 6 carbon atoms.
It is one or more kinds selected from 15 polycyclic alkyl groups and is bonded to an ester group through a tertiary carbon.
All of the above Xs are alkyl groups having 1 to 15 carbon atoms, alkoxy groups, carboxyl groups, ether groups, and 3 to 1 carbon atoms.
One or more hydrogen atoms may be substituted with the cyclic alkyl group, cyclic alkoxy group, or halogen atom of 5. 2. The polymer for a chemically amplified photoresist according to claim 1, wherein X in the general formula (I) is at least one selected from the chemical formulas (II), (III) and (IV). [Chemical 2] 3. A chemically amplified photoresist composition containing the following (X) to (Z) as essential components. (X) The polymer for chemically amplified photoresist according to claim 1 or 2, (Y) a compound that generates an acid by the action of light, and
(Z) A solvent that dissolves (X) and (Y). 4. A method for producing a semiconductor, which comprises using the chemically amplified photoresist composition according to claim 3 and using an ArF excimer laser as an exposure light source.