Resist composition and patterning process

A resist composition comprising a polymer comprising recurring units of acid labile group-substituted (meth)acrylic acid, styrenecarboxylic acid or vinylnaphthalenecarboxylic acid and/or recurring units having an acid labile group-substituted phenolic hydroxyl group, and an acid generator, or a copolymer comprising recurring units of acid labile group-substituted (meth)acrylic acid, styrenecarboxylic acid or vinylnaphthalenecarboxylic acid and/or recurring units having an acid labile group-substituted phenolic hydroxyl group and recurring units having an acid generator,

• said resist composition further comprising a complex of a metal with an acid, the metal being selected from the group consisting of cerium, copper, zinc, iron, indium, yttrium, ytterbium, tin, thulium, scandium, nickel, neodymium, hafnium, zirconium, titanium, lanthanum, silver, barium, holmium, terbium, lutetium, europium, dysprosium, gadolinium, rubidium, strontium, and cesium, and the acid being selected from the group consisting of an alkylsulfonic acid, arylsulfonic acid, alkylsulfonimidic acid, alkylsulfonemethide acid, and tetraphenylboric acid each of which has at least one fluorine atom;
• wherein the polymer comprising recurring units of acid labile group-substituted (meth)acrylic acid, styrenecarboxylic acid or vinylnaphthalenecarboxylic acid and/or recurring units having an acid labile group-substituted phenolic hydroxyl group has recurring units (a1) and/or (a2), as represented by the general formula (1):
• wherein R1 and R3 are each independently hydrogen or methyl, R2 and R4 each are an acid labile group, X1 is a single bond, a C1-C12 linking group having at least one of ester moiety, lactone ring, phenylene moiety and naphthylene moiety, a phenylene group, or a naphthylene group, X2 is a single bond or an ester or amide group, a1 and a2 are numbers in the range:
• 0≦a1≦0.9, 0≦a2≦0.9, and 0<a1+a2<1;
• and
• wherein in addition to the recurring units (a1) and (a2), the polymer comprises recurring units (b1), (b2) or (b3) of a sulfonium salt having the general formula (2):
• wherein R120, R124, and R128 each are hydrogen or methyl, R121 is a single bond, phenylene, —O—R—, or —C(═O)—Y—R—, Y is oxygen or NH, R is a straight, branched or cyclic C1-C6 alkylene group, C3-C10 alkenylene or phenylene group, which may contain a carbonyl, ester, ether or hydroxyl moiety, R122, R123, R125, R126, R127, R129, R130, and R131 are each independently a straight, branched or cyclic C1-C12 alkyl group which may contain a carbonyl, ester or ether moiety, or a C6-C12 aryl, C7-C20 aralkyl, or phenylthio group which may contain a straight, branched or cyclic C1-C10 alkyl, halogen, trifluoromethyl, cyano, nitro, hydroxyl, alkoxy, alkoxycarbonyl or acyloxy radical, Z1 is a single bond or —C(═O)—Z3—R132—, Z2 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, —O—R132— or —C(═O)—Z3—R132—, Z3 is oxygen or NH, R132 is a straight, branched or cyclic C1-C6 alkylene group, alkenylene, or phenylene group, which may contain a carbonyl, ester, ether or hydroxyl moiety, a pair of R122 and R123, R125 and R126, R125 and R127, R126 and R127, R129 and R130, R129 and R131, or R130 and R131 may bond directly or via a methylene moiety or ether bond to form a ring with the sulfur atom, R133 is hydrogen or trifluoromethyl, M− is a non-nucleophilic counter ion, b1, b2 and b3 are in the range of 0≦b1≦0.5, 0≦b2≦0.5, 0≦b3≦0.5, and 0<b1+b2+b3≦0.5.

A resist composition comprising a polymer comprising recurring units of acid labile group-substituted (meth)acrylic acid, styrenecarboxylic acid or vinylnaphthalenecarboxylic acid and/or recurring units having an acid labile group-substituted phenolic hydroxyl group, and an acid generator, or a copolymer comprising recurring units of acid labile group-substituted (meth)acrylic acid, styrenecarboxylic acid or vinylnaphthalenecarboxylic acid and/or recurring units having an acid labile group-substituted phenolic hydroxyl group and recurring units having an acid generator,

• said resist composition further comprising a complex of a metal with an acid, the metal being selected from the group consisting of cerium, copper, zinc, iron, indium, yttrium, ytterbium, tin, thulium, scandium, nickel, neodymium, hafnium, zirconium, titanium, lanthanum, silver, barium, holmium, terbium, lutetium, europium, dysprosium, gadolinium, rubidium, strontium, and cesium, and the acid being selected from the group consisting of an alkylsulfonic acid, arylsulfonic acid, alkylsulfonimidic acid, alkylsulfonemethide acid, and tetraphenylboric acid each of which has at least one fluorine atom;
• wherein the complex is at least one selected from those complexes having the following general formulae:
• wherein R11 is fluorine or an organic group selected from the group consisting of trifluoromethyl, pentafluoroethyl, trifluoroethyl, octafluorobutyl, nonafluorobutyl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 2,4-difluorophenyl, 2,3-difluorophenyl, 3,4-difluorophenyl, 3,5-difluorophenyl, 2,4,5-trifluorophenyl, 2,3,4-trifluorophenyl, 2,3,4,5-tetrafluorophenyl, 2,3,5,6-tetrafluorophenyl, 2,3,4,5,6-pentafluorophenyl, 2-trifluoromethylphenyl, 3-trifluoromethylphenyl, 4-trifluoromethylphenyl, 2,4-di(trifluoromethyl)phenyl, 4-hydroxy-2,3,5,6-tetrafluorophenyl, 4-methoxy-2,3,5,6-tetrafluorophenyl, 4-acetoxy-2,3,5,6-tetrafluorophenyl, 4-pivaloyloxy-2,3,5,6-tetrafluorophenyl, 4-cyclohexylcarbonyloxy-2,3,5,6-tetrafluorophenyl, 4-adamantylcarbonyloxy-2,3,5,6-tetrafluorophenyl, 4-phenylcarbonyloxy-2,3,5,6-tetrafluorophenyl, 4-cyclohexylsulfonyl-2,3,5,6-tetrafluorophenyl, and 4-phenylsulfonyl-2,3,5,6-tetrafluorophenyl,
• R15, R16, R17, R18, and R19 are each independently fluorine, trifluoromethyl, pentafluoroethyl, trifluoroethyl, octafluorobutyl, or nonafluorobutyl, R15 and R16 may bond together to form a ring,
• R20, R21, R22, and R23 are each independently fluorine or trifluoromethyl, each of p, q, r and s is an integer of 1 to 5.

A pattern forming process comprising the steps of coating a resist composition onto a substrate, baking, exposing the resulting resist film to high-energy radiation, and developing with a developer;

• wherein the resist composition comprises recurring units of acid labile group-substituted (meth)acrylic acid, styrenecarboxylic acid or vinylnaphthalenecarboxylic acid and/or recurring units having an acid labile group-substituted phenolic hydroxyl group, and an acid generator, or a copolymer comprising recurring units of acid labile group-substituted (meth)acrylic acid, styrenecarboxylic acid or vinylnaphthalenecarboxylic acid and/or recurring units having an acid labile group-substituted phenolic hydroxyl group and recurring units having an acid generator, and
• said resist composition further comprises a complex of a metal with an acid, the metal being selected from the group consisting of cerium, copper, zinc, iron, indium, yttrium, ytterbium, tin, thulium, scandium, nickel, neodymium, hafnium, zirconium, titanium, lanthanum, silver, barium, holmium, terbium, lutetium, europium, dysprosium, gadolinium, rubidium, strontium, and cesium, and the acid being selected from the group consisting of an alkylsulfonic acid, arylsulfonic acid, alkylsulfonimidic acid, alkylsulfonemethide acid, and tetraphenylboric acid each of which has at least one fluorine atom;
• wherein in the step of exposing the resist film to high-energy radiation, the surface of the substrate underneath the resist film is electrically charged positive.