PHOTORESIST RESIN, METHOD FOR PRODUCING PHOTORESIST RESIN, PHOTORESIST RESIN COMPOSITION, AND METHOD FOR FORMING PATTERN

Abstract

Provided is a resin that exhibits high resist performance because a poorly soluble component with respect to a resist solvent is reduced, and a production method for the resin. Disclosed is a photoresist resin containing an acrylic resin, in which when the photoresist resin is dissolved in propylene glycol monomethyl ether acetate in such a way that a resin solid content concentration is 5 wt %, a polystyrene equivalent turbidity measured using a method described in “Drinking Water Testing Methods” of Japan Water Works Association of 2003, Ministry of Health, Labor and Welfare Ordinance No. 261 of Japan is 30 or less.

Claims

1. A photoresist resin comprising an acrylic resin, wherein when the photoresist resin is dissolved in propylene glycol monomethyl ether acetate in such a way that a resin solid content concentration is 5 wt %, a polystyrene equivalent turbidity measured using a method described in “Drinking Water Testing Methods” of Japan Water Works Association of 2003, Ministry of Health, Labor and Welfare Ordinance No. 261 of Japan is 30 or less.

2. The photoresist resin according to claim 1, comprising at least one polymerization unit selected from the group consisting of polymerization units represented by Formulas (a1) to (a4) ##STR00023## wherein R represents a hydrogen atom, a halogen atom, or an alkyl group that has from 1 to 6 carbon atoms and optionally has a halogen atom; A represents a single bond or a linking group; R.sup.2 to R.sup.4 are the same or different and represent an alkyl group that has from 1 to 6 carbon atoms and optionally has a substituent; R.sup.2 and R.sup.3 are optionally bonded to each other to form a ring; R.sup.5 and R.sup.6 are the same or different and represent an alkyl group that has from 1 to 6 carbon atoms and optionally has a hydrogen atom or a substituent; R.sup.7 represents a —COOR.sup.c group, and the R.sup.c represents a tertiary hydrocarbon group that optionally has a substituent, a tetrahydrofuranyl group, a tetrahydropyranyl group, or an oxepanyl group; n represents an integer from 1 to 3; R.sup.a represents a substituent bonded to a ring Z.sup.1, and each R.sup.a is the same or different and represents an oxo group, an alkyl group, a hydroxy group optionally protected with a protecting group, a hydroxyalkyl group optionally protected with a protecting group, or a carboxy group optionally protected with a protecting group; p represents an integer from 0 to 3; and the ring Z.sup.1 represents an alicyclic hydrocarbon ring having from 3 to 20 carbon atoms.

3. The photoresist resin according to claim 1, comprising at least one polymerization unit selected from the group consisting of polymerization units represented by Formulas (b1) to (b5) ##STR00024## wherein R represents a hydrogen atom, a halogen atom, or an alkyl group that has from 1 to 6 carbon atoms and optionally has a halogen atom; A represents a single bond or a linking group; X represents no bond, a methylene group, an ethylene group, an oxygen atom, or a sulfur atom; Y represents a methylene group or a carbonyl group; Z represents a divalent organic group; V.sup.1 to V.sup.3 are the same or different and represent —CH.sub.2—, [—C(═O)—], or [—C(═O)—O—] with the proviso that at least one of V.sup.1 to V.sup.3 is [—C(═O)—O—]; and R.sup.8 to R.sup.14 are the same or different and represent a hydrogen atom, a fluorine atom, an alkyl group optionally having a fluorine atom, a hydroxy group optionally protected with a protecting group, a hydroxyalkyl group optionally protected with a protecting group, a carboxy group optionally protected with a protecting group, or a cyano group.

4. The photoresist resin according to claim 2, further comprising a polymerization unit represented by Formula (c1) ##STR00025## wherein R represents a hydrogen atom, a halogen atom, or an alkyl group that has from 1 to 6 carbon atoms and optionally has a halogen atom; A represents a single bond or a linking group; R.sup.b represents a hydroxy group optionally protected with a protecting group, a hydroxyalkyl group optionally protected with a protecting group, a carboxy group optionally protected with a protecting group, or a cyano group; q represents an integer from 1 to 5; and a ring Z.sup.2 represents an alicyclic hydrocarbon ring having from 6 to 20 carbon atoms.

5. A production method for the photoresist resin described in claim 1, the production method comprising: adding dropwise a monomer or a solution containing the monomer in the presence of a polymerization initiator to polymerize the monomer; and adding a polymerization inhibitor of 10 ppm or greater to a resin solid content contained in a reaction solution after the polymerization step.

6. The production method for the photoresist resin according to claim 5, wherein the polymerization inhibitor is at least one selected from the group consisting of hydroquinones, phenols, benzoquinones, and the like, and N-oxyl compounds.

7. A photoresist resin composition comprising at least the photoresist resin described in claim 1 and a radiation-sensitive acid generating agent.

8. A pattern formation method comprising at least applying the photoresist resin composition described in claim 7 to a substrate to form a coating film, exposing the coating film, and then dissolving the coating film with an alkali.

9. The photoresist resin according to claim 2, comprising at least one polymerization unit selected from the group consisting of polymerization units represented by Formulas (b1) to (b5) ##STR00026## wherein R represents a hydrogen atom, a halogen atom, or an alkyl group that has from 1 to 6 carbon atoms and optionally has a halogen atom; A represents a single bond or a linking group; X represents no bond, a methylene group, an ethylene group, an oxygen atom, or a sulfur atom; Y represents a methylene group or a carbonyl group; Z represents a divalent organic group; V.sup.1 to V.sup.3 are the same or different and represent —CH.sub.2—, [—C(═O)—], or [—C(═O)—O—] with the proviso that at least one of V.sup.1 to V.sup.3 is [—C(═O)—O—]; and R.sup.8 to R.sup.14 are the same or different and represent a hydrogen atom, a fluorine atom, an alkyl group optionally having a fluorine atom, a hydroxy group optionally protected with a protecting group, a hydroxyalkyl group optionally protected with a protecting group, a carboxy group optionally protected with a protecting group, or a cyano group.

10. The photoresist resin according to claim 3, further comprising a polymerization unit represented by Formula (c1) ##STR00027## wherein R represents a hydrogen atom, a halogen atom, or an alkyl group that has from 1 to 6 carbon atoms and optionally has a halogen atom; A represents a single bond or a linking group; R.sup.b represents a hydroxy group optionally protected with a protecting group, a hydroxyalkyl group optionally protected with a protecting group, a carboxy group optionally protected with a protecting group, or a cyano group; q represents an integer from 1 to 5; and a ring Z.sup.2 represents an alicyclic hydrocarbon ring having from 6 to 20 carbon atoms.

11. The photoresist resin according to claim 9, further comprising a polymerization unit represented by Formula (c1) ##STR00028## wherein R represents a hydrogen atom, a halogen atom, or an alkyl group that has from 1 to 6 carbon atoms and optionally has a halogen atom; A represents a single bond or a linking group; R.sup.b represents a hydroxy group optionally protected with a protecting group, a hydroxyalkyl group optionally protected with a protecting group, a carboxy group optionally protected with a protecting group, or a cyano group; q represents an integer from 1 to 5; and a ring Z.sup.2 represents an alicyclic hydrocarbon ring having from 6 to 20 carbon atoms.

12. The production method for the photoresist resin described in claim 2, the production method comprising: adding dropwise a monomer or a solution containing the monomer in the presence of a polymerization initiator to polymerize the monomer; and adding a polymerization inhibitor of 10 ppm or greater to a resin solid content contained in a reaction solution after the polymerization step.

13. The production method for the photoresist resin described in claim 3, the production method comprising: adding dropwise a monomer or a solution containing the monomer in the presence of a polymerization initiator to polymerize the monomer; and adding a polymerization inhibitor of 10 ppm or greater to a resin solid content contained in a reaction solution after the polymerization step.

14. The production method for the photoresist resin described in claim 4, the production method comprising: adding dropwise a monomer or a solution containing the monomer in the presence of a polymerization initiator to polymerize the monomer; and adding a polymerization inhibitor of 10 ppm or greater to a resin solid content contained in a reaction solution after the polymerization step.

15. The production method for the photoresist resin described in claim 9, the production method comprising: adding dropwise a monomer or a solution containing the monomer in the presence of a polymerization initiator to polymerize the monomer; and adding a polymerization inhibitor of 10 ppm or greater to a resin solid content contained in a reaction solution after the polymerization step.

16. The production method for the photoresist resin described in claim 10, the production method comprising: adding dropwise a monomer or a solution containing the monomer in the presence of a polymerization initiator to polymerize the monomer; and adding a polymerization inhibitor of 10 ppm or greater to a resin solid content contained in a reaction solution after the polymerization step.

17. The production method for the photoresist resin described in claim 11, the production method comprising: adding dropwise a monomer or a solution containing the monomer in the presence of a polymerization initiator to polymerize the monomer; and adding a polymerization inhibitor of 10 ppm or greater to a resin solid content contained in a reaction solution after the polymerization step.

18. The production method for the photoresist resin according to claim 12, wherein the polymerization inhibitor is at least one selected from the group consisting of hydroquinones, phenols, benzoquinones, and the like, and N-oxyl compounds.

19. The production method for the photoresist resin according to claim 13, wherein the polymerization inhibitor is at least one selected from the group consisting of hydroquinones, phenols, benzoquinones, and the like, and N-oxyl compounds.

20. The production method for the photoresist resin according to claim 14, wherein the polymerization inhibitor is at least one selected from the group consisting of hydroquinones, phenols, benzoquinones, and the like, and N-oxyl compounds.

Description

EXAMPLES

[0107] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited by these examples. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the resin were determined by gel permeation chromatography (GPC) measurement using a tetrahydrofuran solvent. Polystyrene was used for a standard sample, and a refractometer (refractive index detector; RI detector) was used as a detector. In addition, the GPC measurement was performed using three columns connected in series, available from Showa Denko K.K. (“KF-806L (trade name)”), under conditions of a column temperature of 40° C., an RI temperature of 40° C., and a tetrahydrofuran flow rate of 0.8 mL/min. The molecular weight distribution (Mw/Mn) was calculated from the measurements.

Example 1 (Preparation of Resin A-1)

[0108] 34.0 g of propylene glycol monomethyl ether acetate was introduced into a round bottom flask equipped with a reflux tube, a stirrer, and a 3-way cock under a nitrogen atmosphere, and the temperature was maintained at 80° C. While stirring, a mixture solution of 10.57 g (0.0476 mol) of 5-oxo-4-oxatricyclo[4.2.1.0.sup.3,7]nonan-2-yl methacrylate, 2.31 g (0.0098 mol) of 3-hydroxyadamantane-1-yl methacrylate, 3.37 g (0.0122 mol) of 1-(adamantane-1-yl)-1-methylpropyl methacrylate, 13.75 g (0.0525 mol) of 2-isopropyladamantane-2-yl methacrylate, 0.75 g of dimethyl-2,2′-azobisisobutyrate [trade name “V-601” available from Wako Pure Chemical Industries, Ltd.], and 136.0 g of propylene glycol monomethyl ether acetate, was added dropwise thereto at a constant rate over a period of 6 hours. After completion of the dropwise addition, the reaction solution was continued to stir for another 2 hours. After the completion of stirring, 9 mg of methoquinone was added, the reaction solution was then cooled to an internal temperature of 23° C. over a period of 4 hours. Immediately thereafter, the reaction solution was added dropwise under stirring into a mixed liquid (25° C.) of heptane and ethyl acetate 9:1 (weight ratio), the amount of the mixed liquid being ten times the amount of the reaction solution. The resulting precipitate was filtered off and dried under reduced pressure, and 23.2 g of the desired resin A-1 was obtained. The collected resin as analyzed by GPC had an Mw (weight average molecular weight) of 10100 and a molecular weight distribution (Mw/Mn) of 1.8.

[0109] The resin A-1 has polymerization units represented by the following formulas.

##STR00020##

Example 2 (Preparation of Resin A-2)

[0110] 34.0 g of cyclohexanone was introduced into a round bottom flask equipped with a reflux tube, a stirrer, and a 3-way cock under a nitrogen atmosphere, and the temperature was maintained at 80° C. While stirring, a mixture solution of 11.06 g (0.0448 mol) of 6-cyano-5-oxo-4-oxatricyclo[4.2.1.0.sup.3,7]nonan-2-yl methacrylate, 15.86 g (0.0605 mol) of 2-isopropyladamantane-2-yl methacrylate, 3.08 g (0.0157 mol) of 1-isopropylcyclopentane-1-yl methacrylate, 0.57 g of dimethyl-2,2′-azobisisobutyrate [trade name “V-601” available from Wako Pure Chemical Industries, Ltd.], and 136.0 g of cyclohexanone, was added dropwise thereto at a constant rate over a period of 6 hours. After completion of the dropwise addition, the reaction solution was continued to stir for another 2 hours. After the completion of stirring, the reaction solution was cooled to an internal temperature of 23° C. over a period of 10 minutes. Immediately thereafter, 21 mg of hydroquinone was added and stored at 23° C. for one day until purification operation. After storage, the reaction solution was added dropwise under stirring into a mixed liquid (25° C.) of heptane and ethyl acetate 9:1 (weight ratio), the amount of the mixed liquid being ten times the amount of the reaction solution. The resulting precipitate was filtered off and dried under reduced pressure, and 19.5 g of the desired resin A-2 was obtained. The collected resin as analyzed by GPC had an Mw (weight average molecular weight) of 10200 and a molecular weight distribution (Mw/Mn) of 1.8.

[0111] The resin A-2 has polymerization units represented by the following formulas.

##STR00021##

Example 3 (Preparation of Resin A-3)

[0112] 34.0 g of propylene glycol monomethyl ether acetate was introduced into a round bottom flask equipped with a reflux tube, a stirrer, and a 3-way cock under a nitrogen atmosphere, and the temperature was maintained at 80° C. While stirring, a mixture solution of 8.76 g (0.0395 mol) of 5-oxo-4-oxatricyclo[4.2.1.0.sup.3,7]nonan-2-yl methacrylate, 4.40 g (0.0259 mol) of 2-oxotetrahydrofuran-3-yl methacrylate, 8.26 g (0.0299 mol) of 1-(adamantane-1-yl)-1-methylpropyl methacrylate, 8.58 g (0.0408 mol) of 1-(cyclohexane-1-yl)-1-methylethyl methacrylate, 0.90 g of dimethyl-2,2′-azobisisobutyrate [trade name “V-601” available from Wako Pure Chemical Industries, Ltd.], and 136.0 g of propylene glycol monomethyl ether acetate, was added dropwise thereto at a constant rate over a period of 6 hours. After completion of the dropwise addition, the reaction solution was continued to stir for another 2 hours. After the completion of stirring, 6 mg of 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxyl free radical was added, and the reaction solution was cooled to an internal temperature of 23° C. over a period of 4 hours, and then stored at 23° C. for one day until the purification operation. After storage, the reaction solution was added dropwise under stirring into a mixed liquid (25° C.) of heptane and ethyl acetate 9:1 (weight ratio), the amount of the mixed liquid being ten times the amount of the reaction solution. The resulting precipitate was filtered off and dried under reduced pressure, and 24.7 g of the desired resin A-3 was obtained. The collected resin as analyzed by GPC had an Mw (weight average molecular weight) of 14800 and a molecular weight distribution (Mw/Mn) of 2.0.

[0113] The resin A-3 has polymerization units represented by the following formulas.

##STR00022##

Comparative Example 1 (Preparation of Resin B-1)

[0114] 23.4 g of the desired resin B-1 was obtained in the same manner as in Example 1 except that no methoquinone was added after the completion of stirring. The collected resin as analyzed by GPC had an Mw (weight average molecular weight) of 10200 and a molecular weight distribution (Mw/Mn) of 1.9.

Comparative Example 2 (Preparation of Resin B-2)

[0115] 19.6 g of the desired resin B-2 was obtained in the same manner as in Example 2 except that no hydroquinone was added after cooling of the reaction solution. The collected resin as analyzed by GPC had an Mw (weight average molecular weight) of 10100 and a molecular weight distribution (Mw/Mn) of 1.8.

Comparative Example 3 (Preparation of Resin B-3)

[0116] 24.6 g of the desired resin B-3 was obtained in the same manner as in Example 3 except that 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxyl free radical was not added after the completion of stirring. The collected resin as analyzed by GPC had an Mw (weight average molecular weight) of 15100 and a molecular weight distribution (Mw/Mn) of 2.0.

[0117] [Evaluation of Turbidity]

[0118] The resins A-1 to 3 and B-1 to 3 were dissolved in propylene glycol monomethyl ether acetate in such a way that the solid content concentration was 5 wt %, and respective resin solutions were prepared. The polystyrene equivalent turbidity of the resin solution was measured using a turbidity meter (model number: NDH-300A, available from Nippon Denshoku Industries Co., Ltd.) according to “Drinking Water Testing Methods” of Japan Water Works Association of 2003, Ministry of Health, Labor and Welfare Ordinance No. 261 of Japan. A specific procedure is as follows.

[0119] Turbidity measurement was performed on a turbidity standard solution (polystyrene) 100° II available from FUJIFILM Wako Pure Chemical Corporation with an NDH-300A, and, as a result, the turbidity was 36.62. From this value, it can be seen that when a value measured with the NDH-300A is 1.00, the polystyrene equivalent turbidity is 2.731. In other words, the polystyrene equivalent turbidity “Y” can be derived by the following equation. In the equation, “X” is a measured value.

Y=2.731X

[0120] The polystyrene equivalent turbidity of the resin solution was determined according to the above formula.

TABLE-US-00001 TABLE 1 Resin Mw Mw/Mn Turbidity A-1 10100 1.8 <1 A-2 10200 1.8 <1 A-3 14800 2.0 <1 B-1 10200 1.9 145 B-2 10100 1.8 82 B-3 15100 2.0 98

[0121] As can be seen from the evaluation results, it was clear that the resin (resins A-1 to 3) of an embodiment of the present invention had low polystyrene equivalent turbidity. On the other hand, it was clear that the resins B-1 to 3 had high polystyrene equivalent turbidity and were incompatible with photoresist applications. From this, it is conceived that the resin of an embodiment of the present invention can form a fine pattern with good precision.

[0122] To summarize the above, configurations and variations of the present invention are described below.

[0123] [1] A photoresist resin composed of an acrylic resin, wherein when the photoresist resin is dissolved in propylene glycol monomethyl ether acetate in such a way that a resin solid content concentration is 5 wt %, a polystyrene equivalent turbidity measured using a method described in “Drinking Water Testing Methods” of Japan Water Works Association of 2003, Ministry of Health, Labor and Welfare Ordinance No. 261 of Japan is 30 or less, 20 or less, 10 or less, 5 or less, or 3 or less.

[0124] [2] The photoresist resin according to [1], containing at least one polymerization unit selected from the group consisting of polymerization units represented by Formulas (a1) to (a4), where R represents a hydrogen atom, a halogen atom, or an alkyl group that has from 1 to 6 carbon atoms and may have a halogen atom; A represents a single bond or a linking group; R.sup.2 to R.sup.4 are the same or different and represent an alkyl group that has from 1 to 6 carbon atoms and may have a substituent; R.sup.2 and R.sup.3 may be bonded to each other to form a ring; R.sup.5 and R.sup.6 are the same or different and represent an alkyl group that has from 1 to 6 carbon atoms and may have a hydrogen atom or a substituent; R.sup.7 represents a —COOR.sup.c group, and the R.sup.c represents a tertiary hydrocarbon group that may have a substituent, a tetrahydrofuranyl group, a tetrahydropyranyl group, or an oxepanyl group; n represents an integer of 1 to 3; R.sup.a represents a substituent bonded to a ring Z.sup.1, and each R.sup.a is the same or different and represents an oxo group, an alkyl group, a hydroxy group that may be protected with a protecting group, a hydroxyalkyl group that may be protected with a protecting group, or a carboxy group that may be protected with a protecting group; p represents an integer of 0 to 3; and the ring Z.sup.1 represents an alicyclic hydrocarbon ring having from 3 to 20 carbon atoms.

[0125] [3] The photoresist resin according to [2], wherein a content of at least one polymerization unit selected from the group consisting of the polymerization units represented by Formulas (a1) to (a4) is from 1 to 99 mol % or from 5 to 95 mol %, based on a total amount of the monomer units constituting the resin.

[0126] [4] The photoresist resin according to any one of [1] to [3], containing at least one polymerization unit selected from the group consisting of polymerization units represented by Formulas (b1) to (b5), where R represents a hydrogen atom, a halogen atom, or an alkyl group that has from 1 to 6 carbon atoms and may have a halogen atom; A represents a single bond or a linking group; X represents no bond, a methylene group, an ethylene group, an oxygen atom, or a sulfur atom; Y represents a methylene group or a carbonyl group; Z represents a divalent organic group; V.sup.1 to V.sup.3 are the same or different and represent —CH.sub.2—, [—C(═O)—], or [—C(═O)—O—] with the proviso that at least one of V.sup.1 to V.sup.3 is [—C(═O)—O—]; and R.sup.8 to R.sup.14 are the same or different and represent a hydrogen atom, a fluorine atom, an alkyl group that may have a fluorine atom, a hydroxy group that may be protected with a protecting group, a hydroxyalkyl group that may be protected with a protecting group, a carboxy group that may be protected with a protecting group, or a cyano group.

[0127] [5] The photoresist resin according to [4], wherein a content of at least one polymerization unit selected from the group consisting of the polymerization units represented by Formulas (b1) to (b5) is from 1 to 99 mol % or from 5 to 95 mol %, based on a total amount of the monomer units constituting the resin.

[0128] [6] The photoresist resin according to any one of [2] to [5], further containing a polymerization unit represented by Formula (c1), where R represents a hydrogen atom, a halogen atom, or an alkyl group that has from 1 to 6 carbon atoms and may have a halogen atom; A represents a single bond or a linking group; R.sup.b represents a hydroxy group that may be protected with a protecting group, a hydroxyalkyl group that may be protected with a protecting group, a carboxy group that may be protected with a protecting group, or a cyano group; q represents an integer from 1 to 5; and a ring Z.sup.2 represents an alicyclic hydrocarbon ring having from 6 to 20 carbon atoms.

[0129] [7] The photoresist resin according to [6], wherein a content of a polymerization unit represented by Formula (c1) is from 1 to 99 mol % or from 5 to 95 mol %, based on the total amount of the monomer units constituting the resin.

[0130] [8] The photoresist resin according to any one of [1] to [7], wherein a weight average molecular weight (Mw) is from 1000 to 50000 or from 3000 to 20000.

[0131] [9] The photoresist resin according to any one of [1] to [8], wherein a molecular weight distribution (ratio of the weight average molecular weight and a number average molecular weight: Mw/Mn) is 3.5 or less, from 1.1 to 3.0, or from 1.2 to 2.5.

[0132] [10] The photoresist resin according to any one of [1] to [9], wherein an acid value is 0.10 mmol/g or less, 0.05 mmol/g or less, or 0.03 mmol/g or less.

[0133] [11] A production method for the photoresist resin described in any one of [1] to [10], the production method including:

[0134] adding dropwise a monomer or a solution containing the monomer in the presence of a polymerization initiator to polymerize the monomer; and

[0135] adding a polymerization inhibitor of from 10 ppm or greater, from 50 to 2000 ppm, from 100 to 1000 ppm, or from 200 to 500 ppm to a resin solid content contained in a reaction solution after the polymerization step.

[0136] [12] The production method for the photoresist resin according to [11], wherein the polymerization inhibitor is at least one selected from the group consisting of hydroquinones, phenols, benzoquinones, and the like, and N-oxyl compounds.

[0137] [13] A photoresist resin composition containing at least the photoresist resin described in any one of [1] to [12] and a radiation-sensitive acid generating agent.

[0138] [14] A pattern formation method including at least applying the photoresist resin composition described in [13] to a substrate to form a coating film, exposing the coating film, and then dissolving the coating film with an alkali.

INDUSTRIAL APPLICABILITY

[0139] The resin of an embodiment of the present invention exhibits high resist performance because a poorly soluble component with respect to a resist solvent is reduced. Since the composition of an embodiment of the present invention contains the resin in which the poorly soluble component with respect to the resist solvent is reduced, high resist performance can be exhibited, and a fine pattern can be formed with good precision by using the composition.