PHOTOACID GENERATOR AND CHEMICALLY AMPLIFIED POSITIVE-TYPE PHOTORESIST COMPOSITION FOR THICK FILM COMPRISING THE SAME

Abstract

A non-ionic photoacid generator and a chemically amplified positive-type photoresist composition for a thick film including the non-ionic photoacid generator. The non-ionic photoacid generator may not only exhibit high solubility in a solvent of the photoresist composition, but may also exhibit chemical and thermal stability and high sensitivity. In particular, the non-ionic photoacid generator is decomposed by light to generate an acid, and at the same time, can exhibit a corrosion preventing effect on a metal substrate.

Claims

1. A non-ionic photoacid generator comprising at least one functional group represented by the following Chemical Formula 1: ##STR00021## wherein, in Chemical Formula 1, R.sup.1 is a C1 to C10 aliphatic hydrocarbon group substituted or unsubstituted with at least one of a halogen atom, an alkylthio group, and an alicyclic hydrocarbon group; a C1 to C10 perfluoroalkyl group; a C6 to C20 aryl group substituted or unsubstituted with at least one of a halogen atom, an alkylthio group, an alkyl group, and an acyl group; or a C7 to C20 arylalkyl group substituted or unsubstituted with a halogen atom and an alkylthio group, and Z is a divalent group derived from triazole.

2. The non-ionic photoacid generator of claim 1, wherein Z is a group represented by the following Chemical Formula 2a or 2b: ##STR00022## wherein, in Chemical Formulae 2a and 2b, R.sup.2 is hydrogen, a C3 to C10 alkyl group, or a C1 to C10 hydroxyalkyl group, R.sup.3 is a chemical bond, a C1 to C10 alkylene group, or a group represented by the following Chemical Formula 3, and when R.sup.2 is a C3 to C10 alkyl group and R.sup.3 is a C1 to C10 alkylene group, they are connected to each other to form a C4 to C20 aliphatic ring, ##STR00023## wherein, in Chemical Formula 3, R.sup.a is a chemical bond or a C1 to C10 alkylene group, R.sup.b is a C1 to C10 alkylene group, n is an integer of 1 to 10, and when n is 2 or more, each R.sup.b, which is repeated two or more times, the same or different from each other.

3. The non-ionic photoacid generator of claim 2, wherein the non-ionic photoacid generator is represented by the following Chemical Formula 4a or 4b: ##STR00024## wherein, in Chemical Formulae 4a and 4b, R.sup.1, R.sup.2, and R.sup.3 are as defined above in Chemical Formulae 1, 2a, 2b, and 3, T is H, (CO)OH, O(CO)OH, (CO)NH.sub.2, NH(CO)H, OCH.sub.3, SH, NH.sub.2, NO.sub.2, CF.sub.3, or SF.sub.3, and R.sup.c is a C4 to C20 aliphatic ring.

4. The non-ionic photoacid generator of claim 2, wherein the non-ionic photoacid generator is represented by the following Chemical Formula 5a or 5b: ##STR00025## wherein, in Chemical Formulae 5a and 5b, R.sup.1, R.sup.2, and R.sup.3 are as defined above in Chemical Formulae 1, 2a, 2b, and 3.

5. A chemically amplified positive-type photoresist composition for a thick film comprising the non-ionic photoacid generator of claim 1.

6. The non-ionic photoacid generator of claim 1, comprising one, two, three or four functional groups represented by Chemical Formula 1 as defined in claim 1.

7. The non-ionic photoacid generator of claim 1, wherein R.sup.1 is methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, isoamyl, tert-amyl, hexyl, 2-hexyl, 3-hexyl, heptyl, 2-heptyl, 3-heptyl, isoheptyl, tert-heptyl, octyl, isooctyl, tert-octyl, 2-ethylhexyl, nonyl, isononyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, trifluoromethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, tridecylfluorohexyl, heptafluorooctyl, 2,2,2-trifluoroethyl, 1,1-difluoroethyl, 1,1-difluoropropyl, 1,1,2,2-tetrafluoropropyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, 1,1,2,2-tetrafluorotetradecyl, phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-vinylphenyl, 3-isopropylphenyl, 4-isopropylphenyl, 4-butylphenyl, 4-isobutylphenyl, 4-tert-butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4-(2-ethylhexyl)phenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-di-tert-butylphenyl, 2,5-di-tert-butylphenyl, 2,6-di-tert-butylphenyl, 2,4-di-tert-pentylphenyl, 2,5-di-tert-amylphenyl, 2,5-di-tert-octylphenyl, cyclohexylphenyl, biphenyl, 2,4,5-trimethylphenyl, 2,4,6-trimethylphenyl, 2,4,6-triisopropylphenyl, pentafluorophenyl, chlorophenyl, dichlorophenyl, trichlorophenyl, 2,4-bis(trifluoromethyl)phenyl, bromoethylphenyl, 4-methylthiophenyl, 4-butylthiophenyl, 4-octylthiophenyl, 4-dodecylthiophenyl, 1,2,5,6-tetrafluoro-4-methylthiophenyl, 1,2,5,6-tetrafluoro-4-butylthiophenyl, 1,2,5,6-tetrafluoro-4-dodecylthiophenyl, benzyl, phenethyl, 2-phenylpropan-2-yl, diphenylmethyl, triphenylmethyl, styryl, cinnamyl, pentafluorophenylmethyl, phenyldifluoromethyl, 2-phenyl-tetrafluoroethyl, 2-(pentafluorophenyl)ethyl, p-methylthiobenzyl, 2,3,5,6-tetrafluoro-4-methylthiophenylethyl, acetylphenyl, acetylnaphthyl, benzoylphenyl, 1-anthraquinolyl, or 2-anthraquinolyl group.

8. The chemically amplified positive-type photoresist composition for a thick film of claim 5, wherein the composition does not comprise a separate corrosion inhibitor.

9. The chemically amplified positive-type photoresist composition for a thick film of claim 5, wherein the composition further comprises an alkali developable polymer resin, a photoinitiator and an organic solvent.

10. A chemically amplified positive-type photoresist composition for a thick film comprising the non-ionic photoacid generator of claim 2.

11. A chemically amplified positive-type photoresist composition for a thick film comprising the non-ionic photoacid generator of claim 3.

12. A chemically amplified positive-type photoresist composition for a thick film comprising the non-ionic photoacid generator of claim 4.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0089] Hereinafter, preferred examples are provided for better understanding. However, these examples are for illustrative purposes only, and the invention is not intended to be limited by these examples.

SYNTHESIS EXAMPLE A

[0090] ##STR00013##

[0091] Compound a1 (5-bromobenzo[de]isochromene-1,3-dione)

[0092] Compound a2 (5-azidobenzo[de]isochromene-1,3-dione)

[0093] Compound a3 (5-azido-2-hydroxy-1H-benzo[de]isoquinoline-1,3(2H)-dione)

[0094] Compound a4 (5-azido-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl trifluoromethanesulfonate)

[0095] (1) Synthesis of Compound a2

[0096] Compound a1 (1.0 equiv.) was dissolved in dimethylformamide (DMF), and then NaN.sub.3 (1.1 equiv.) was added thereto, followed by refluxing at 100 C. for 12 hours. Then, 20 g each of water and chloroform were added to the reaction solution, and the mixture was subjected to oil-water separation to obtain an organic layer, followed by washing once with 1 N hydrochloric acid and then five times with water. The solid phase obtained by concentrating the organic phase was dissolved in chloroform, and the filtrate obtained by filtration was recrystallized by adding methanol to the filtrate. The obtained crystals were taken by filtration and vacuum-dried at 45 C. to obtain 10 g of Compound a2 (95% yield).

[0097] .sup.1H NMR (DMSO-d.sub.6, Standard material TMS) (ppm): 8.78 (1H, d), 8.69-8.65 (3H, m), 8.01 (1H, t)

[0098] (2) Synthesis of Compound a3

[0099] Ethanol was added to a flask containing Compound a2 (1.0 equiv.), NH.sub.2OH-HCl (hydroxylamine hydrochloride, 1.5 equiv.), and KOH (1.5 equiv.), and then refluxed for 1 hour to remove the solvent. Water and HCl (1 N) were added, and the resulting colorless solid was filtered off, followed by washing with diethyl ether to obtain 16 g of Compound a3 (73% yield).

[0100] .sup.1H NMR (DMSO-d.sub.6, Standard material TMS) (ppm): 8.42-8.35 (4H, m), 7.97 (1H, t)

[0101] (3) Synthesis of Compound a4

[0102] Compound a3 (1.0 equiv.) was dissolved in chloroform, and then pyridine (1.5 equiv.) was added thereto, followed by cooling to 0 C. Tf.sub.2O (trifluoromethanesulfonic anhydride, 1.3 equiv.) was added slowly thereto and stirred at room temperature for 3 hours. After the reaction was completed, water was added. Then, the separated organic layer was washed with a NaOH aqueous solution (0.2 N), HCl (1 N) and water, dried with magnesium sulfate, and filtered, followed by removing the solvent. 15 g of Compound a4 (53% yield) was obtained by column chromatography purification.

[0103] .sup.1H NMR (DMSO-d.sub.6, Standard material TMS) (ppm): 8.41-8.35 (4H, m), 7.87 (1H, t)

##STR00014##

[0104] Compound A (1-(1,3-dioxo-2-(((trifluoromethyl)sulfonyl)oxy)-2,3-dihydro-1H-benzo[de]isoquinolin-5-yl)-1H-1,2,3-triazole-4-carboxylic acid) was obtained by a click reaction between the Compound a4 (5-azido-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl trifluoromethanesulfonate) and propiolic acid.

[0105] Specifically, the Compound a4 and the propiolic acid were dissolved in chloroform in an amount of 1.0 equiv., respectively, and then the previously prepared catalyst solution (CuBr/PMDETA=1/1 mol/mol) (PMDETA:N,N,N,N,N-pentamethyldiethylenetriamine) was added thereto in an amount of 0.05 equiv. based on CuBr, followed by stirring for 12 hours. The reaction mixture was washed with water and HCl (1 N), and then the organic layer was concentrated and purified by column chromatography to obtain 24 g of Compound A (78% yield).

[0106] .sup.1H NMR (DMSO-d.sub.6, Standard material TMS) (ppm): 8.43-8.35 (4H, m), 8.08 (1H, s), 7.86 (1H, t)

SYNTHESIS EXAMPLE B

[0107] ##STR00015##

[0108] Compound B (1-(1-(1,3-dioxo-2-(((trifluoromethyl)sulfonyl)oxy)-2,3-dihydro-1H-benzo[de]isoquinolin-5-yl)-1H-1,2,3-triazol-4-yl)-2,5,8,11,14-pentaoxaheptadecan-17-oic acid) was obtained by a click reaction between the Compound a4 (5-azido-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl trifluoromethanesulfonate) and a Compound b1 (Alkyne-PEG5-acid).

[0109] Specifically, the Compound a4 and the Compound b1 were dissolved in chloroform in an amount of 1.0 equiv., respectively, and then the previously prepared catalyst solution (CuBr/PMDETA=1/1 mol/mol) (PMDETA:N,N,N,N,N-pentamethyldiethylenetriamine) was added thereto in an amount of 0.05 equiv. based on CuBr, followed by stirring for 12 hours. The reaction mixture was washed with water and HCl (1 N), and then the organic layer was concentrated and purified by column chromatography to obtain 15 g of Compound B (56% yield).

[0110] .sup.1H NMR (DMSO-d.sub.6, Standard material TMS) (ppm): 8.41-8.36 (4H, m), 8.10 (1H, s), 7.88 (1H, t), 4.11 (2H,s), 3.60 (2H, t), 3.51 (16H, m), 2.40 (2H, t)

SYNTHESIS EXAMPLE C

[0111] ##STR00016##

[0112] Compound C (5-(4,5,6,7,8,9-hexahydro-1H-cycloocta[d][1,2,3]triazol-1-yl)-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl trifluoromethanesulfonate) was obtained by a click reaction between the Compound a4 (5-azido-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl trifluoromethanesulfonate) and cyclooctyne.

[0113] Specifically, the Compound a4 and the cyclooctyne were dissolved in chloroform in an amount of 1.0 equiv., respectively, and then the previously prepared catalyst solution (CuBr/PMDETA=1/1 mol/mol) (PMDETA:N,N,N,N,N-pentamethyldiethylenetriamine) was added thereto in an amount of 0.05 equiv. based on CuBr, followed by stirring for 12 hours. The reaction mixture was washed with water and HCl (1 N), and then the organic layer was concentrated and purified by column chromatography to obtain 21 g of Compound C (60% yield).

[0114] .sup.1H NMR (DMSO-d.sub.6, Standard material TMS) (ppm): 8.41-8.34 (4H, m), 7.88 (1H, t), 2.65 (4H,t), 1.74 (4H, m), 1.32 (4H, t)

SYNTHESIS EXAMPLE D

[0115] ##STR00017##

[0116] Compound a1 (5-bromobenzo[de]isochromene-1,3-dione)

[0117] Compound d2 (5-(hex-1-yn-1-yl)benzo[de]isochromene-1,3-dione)

[0118] Compound d3 (5-(hex-1-yn-1-yl)-2-hydroxy-1H-benzo[de]isoquinoline-1,3(2H)-dione)

[0119] Compound d4 (5-(hex-1-yn-1-yl)-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl trifluoromethanesulfonate)

[0120] (1) Synthesis of Compound d2

[0121] Under a nitrogen atmosphere, Compound al (1.0 equiv.) was dissolved in tetrahydrofuran (THF), and then triphenylphosphine (PPh3) (0.08 equiv.) and triethylamine (TEA) (2.0 equiv.) were added thereto, followed by mixing for 1 hour. Then, CuI (0.03 equiv.) and Pd(PPh3).sub.2Cl.sub.2 (0.01 equiv.) were added to the reaction solution, and 1-hexyne (1.0 equiv.) was slowly added dropwise over 3 hours.

[0122] Thereafter, the mixture was reacted for 15 hours while refluxing, and the temperature was lowered to room temperature. Then, 20 g of water was added thereto and the mixture was filtered to obtain a solid material. The solid was subjected to oil-water separation to obtain an organic layer. Then, the solid phase obtained by concentrating the organic layer was dissolved in acetonitrile (CAN), and recrystallized. The obtained crystals were taken by filtration and vacuum-dried at 45 C. to obtain 25 g of Compound d2 (70% yield).

[0123] .sup.1H NMR (DMSO-d.sub.6, Standard material TMS) (ppm): 8.75-8.71 (2H, m), 8.57 (1H, s), 8.40 (1H, s), 8.03 (1H, t), 2.46 (2H, t), 1.44 (2H, m), 1.32 (2H, m), 0.89 (3H, t)

[0124] (2) Synthesis of Compound d3

[0125] Ethanol was added to a flask containing Compound d2 (1.0 equiv.), NH.sub.2OH-HCl (hydroxylamine hydrochloride, 1.5 equiv.), and KOH (1.5 equiv.), and then refluxed for 1 hour to remove the solvent. Water and HCl (1 N) were added, and the resulting colorless solid was filtered off, followed by washing with diethyl ether to obtain 21 g of Compound d3 (52% yield).

[0126] .sup.1H NMR (DMSO-d.sub.6, Standard material TMS) (ppm): 8.42-8.38 (2H, m), 8.28 (1H, s), 8.11 (1H, s), 7.89 (1H, t), 2.46 (2H, t), 1.44 (2H, m), 1.30 (2H, m), 0.89 (3H, t)

[0127] (3) Synthesis of Compound d4

[0128] Compound d3 (1.0 equiv.) was dissolved in chloroform, and then pyridine (1.5 equiv.) was added thereto, followed by cooling to 0 C. Tf.sub.2O (trifluoromethanesulfonic anhydride, 1.3 equiv.) was slowly added thereto and stirred at room temperature for 3 hours. After the reaction was completed, water was added. Then, the separated organic layer was washed with a NaOH aqueous solution (0.2 N), HCl (1 N), and water, dried with magnesium sulfate, and filtered, followed by removing the solvent. 17 g of Compound d4 (65% yield) was obtained by column chromatography purification.

[0129] .sup.1H NMR (DMSO-d.sub.6, Standard material TMS) (ppm): 8.44-8.40 (2H, m), 8.30 (1H, s), 8.11 (1H, s), 7.90 (1H, t), 2.46 (2H, t), 1.44 (2H, m), 1.30 (2H, m), 0.89 (3H, t)

##STR00018##

[0130] Compound D was obtained by a click reaction between the Compound d4 (5-(hex-1-yn-1-yl)-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl trifluoromethanesulfonate) and Compound d5 (4-Arm PEG-Azide: a multiarm PEG derivative with azido (N3) groups at each terminal of the four arms connected to one pentaerythritol core).

[0131] Specifically, the Compounds d4 and d5 (4-Arm PEG-Azide) were dissolved in chloroform in an amount of 1.0 equiv., respectively, and then the previously prepared catalyst solution (CuBr/PMDETA=1/1 mol/mol) (PMDETA:N,N,N,N,N-pentamethyldiethylenetriamine) was added thereto in an amount of 0.05 equiv. based on CuBr, followed by stirring for 12 hours. The reaction mixture was washed with water and HCl (1 N), and then the organic layer was concentrated and purified by recrystallization to obtain 42 g of Compound D (83% yield).

[0132] .sup.1H NMR (DMSO-d.sub.6, Standard material TMS) (ppm): 8.44-8.40 (8H, m), 8.30 (4H, s), 8.11 (4H, s), 7.90 (4H, t), 3.79 (8H, s), 3.70 (16H, t), 3.54-3.52 (72H, m), 2.44 (8H, t), 1.62 (8H, m), 1.33 (8H, m), 1.06 (12H, t)

EXAMPLES 1 TO 8

[0133] The components shown in Table 1 below were mixed to prepare chemically amplified positive-type photoresist compositions for a thick film of Examples 1 to 8, respectively.

[0134] Specifically, the photoresist composition was prepared by mixing 100 g of the alkali developable resin (R1-R3), 5 g of the photoacid generator (A1-A4), and 10 g of the organic solvent (PGMEA).

[0135] In the following Table 1, the components applied to the above examples are as follows.

[0136] [R1] m,p-Cresol novolac resin (Mw 12,000 g/mol, ADR 500 /s)

[0137] [R2] Acetal protected polyhydroxystyrene (PHS) resin (Mw 15,300 g/mol, Substitution rate 25%)

[0138] [R3] Acrylic resin (Mw 65,000 g/mol)

##STR00019##

[0139] [A1] The photoacid generator (Compound A according to Synthesis Example A)

[0140] [A2] The photoacid generator (Compound B according to Synthesis Example B)

[0141] [A3] The photoacid generator (Compound C according to Synthesis Example C)

[0142] [A4] The photoacid generator (Compound D according to Synthesis Example D)

COMPARATIVE EXAMPLES 1 TO 3

[0143] The components shown in Table 1 below were mixed to prepare chemically amplified positive-type photoresist compositions for a thick film of Comparative Examples 1 to 3, respectively.

[0144] Specifically, the photoresist composition was prepared by mixing 100 g of the alkali developable resin (R1-R3), 1 g of the photoacid generator (NIT), 1 g of the corrosion inhibitor (BTA), and 10 g of the organic solvent (PGMEA).

[0145] In the following Table 1, NIT and BTA of the above comparative examples are as follows.

[0146] [NIT] 1,3-Dioxo-1H-benzo[de]isoquinolin-2(3H)-yl trifluoromethanesulfonate

##STR00020##

[0147] [BTA] Benzotriazole

TABLE-US-00001 TABLE 1 R1 R2 R3 A1 A2 A3 A4 NIT BTA Example 1 40 60 5 Example 2 40 60 5 Example 3 40 60 5 Example 4 40 60 5 Example 5 30 70 5 Example 6 30 70 5 Example 7 100 5 Example 8 100 5 Comp. Ex. 1 40 60 1 1 Comp. Ex. 2 30 70 1 1 Comp. Ex. 3 100 1 1

[0148] The content of the components listed in the Table 1 is based on the solid content. The sum of the alkali developable resin is 100 parts by weight, and the photoacid generator and the corrosion inhibitor are based on 100 parts by weight of the alkali developable resin.

EXPERIMENTAL EXAMPLES

[0149] Using the respective photoresist compositions according to the examples and comparative examples, semiconductor devices were patterned in the following manner.

[0150] The photoresist composition was spin-coated on a 4-inch Si wafer coated with copper (Cu) to a thickness of about 2000 , and dried at 120 C. for 4 minutes to form a photoresist layer of about a 50 m thickness. The wafer was exposed using an i-line stepper (equipped with a photomask having hole patterns of about 10, 20, 30, 40, and 50 m size). The exposed wafer was dried at 100 C. for 3 minutes, and then developed for 300 seconds using a developing solution (about 2.38 wt % tetramethylammonium hydroxide aqueous solution).

[0151] After the patterning, physical properties of the photoresist composition were evaluated in the following manner.

[0152] (1) Sensitivity (Exposure Dose, mJ/cm.sup.2)

[0153] The photoresist compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3 were spin-coated on a glass substrate and dried on a hot plate at 120 C. for 2 minutes. Then, they were exposed using a step mask, further dried on the hot plate at 100 C. for 2 minutes, and then developed in an aqueous solution of tetramethylammonium hydroxide (TMAH). The exposure dose of the step mask pattern and the photoresist (PR) pattern with the same CD size was evaluated as sensitivity.

[0154] (2) Occurrence of Footing at Lower Part of Pattern

[0155] The photoresist compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3 were spin-coated on a glass substrate and dried on a hot plate at 120 C. for 2 minutes. Then, they were exposed using a step mask, further dried on the hot plate at 100 C. for 2 minutes, and then developed in an aqueous solution of tetramethylammonium hydroxide (TMAH). A reduced value of the hole diameter from the top to the bottom of the thick film resist pattern was evaluated as a footing length. The footing property of the PR was evaluated based on the following criteria.

[0156] : A footing length of more than 0 nm and 200 nm or less

[0157] : A footing length of more than 200 nm and 500 nm or less

[0158] : A footing length of more than 500 nm and 1 m or less

[0159] : A footing length of more than 1 m

[0160] (3) Developability (Presence or Absence of Residue)

[0161] A thick film resist pattern was prepared in the same manner as the occurrence of footing at lower part of pattern, and presence or absence of residue in the developing part was observed to be an index of developability. The developability was evaluated based on the following criteria.

[0162] : No residue formed

[0163] : Some residue formed around the pattern

[0164] : Residue formed in the whole developing part

[0165] (4) Resistance to Plating Solution

[0166] The photoresist compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3 were applied on a substrate using a spin coater, and then subjected to a process such as prebake and postbake to form a resist film. The resist film was immersed in a Cu plating solution at room temperature for 24 hours to examine whether there was a change in thickness of the resist film. The rate of change in thickness was evaluated based on the following criteria.

[0167] : A rate of change in thickness of within 1%

[0168] : A rate of change in thickness of more than 1% and 3% or less

[0169] : A rate of change in thickness of more than 3% and 10% or less

[0170] : A rate of change in thickness of more than 10%

[0171] (5) Heat Resistance

[0172] The photoresist compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3 were spin-coated on a glass substrate and dried on a hot plate at 120 C. for 2 minutes. Then, they were exposed using a step mask, and further dried on the hot plate at 100 C. for 2 minutes. Thereafter, the coated wafer was tilted at 45 for 20 seconds and developed in an aqueous solution of tetramethylammonium hydroxide (TMAH). The heat resistance was evaluated based on the following criteria by measuring how much the prepared thick film resist pattern tilted sideways (perpendicularity of the pattern slope).

[0173] : No tilt

[0174] : More than 0 and 5 or less

[0175] : More than 5 and 10 or less

[0176] : More than 10

TABLE-US-00002 TABLE 2 Resistance Sensitivity to Plating Heat (mJ/cm.sup.2) Footing Developability solution resistance Example 1 350 Example 2 310 Example 3 340 Example 4 280 Example 5 210 Example 6 180 Example 7 250 Example 8 210 Comp. 870 X X Ex. 1 Comp. 790 X Ex. 2 Comp. 990 X X Ex. 3

[0177] Referring to Table 2 above, the photoresist compositions according to the examples showed excellent sensitivity and developability at a low exposure dose, and were confirmed to exhibit excellent resistance to the plating solution even without a separate corrosion inhibitor (NIT).