Resist composition and patterning process
A copolymer of an alkali-soluble (α-trifluoromethyl)-acrylate and a norbornene derivative is useful as an additive to a resist composition. When processed by immersion lithography, the resist composition exhibits excellent water repellency and water slip and forms a pattern with few development defects.
1. A resist composition comprising (A) a polymer P1 comprising repeat units of the following general formulae (1a) and (2a), (B) a polymer having a structure containing one or both of a lactone ring and a hydroxyl group, and/or a structure derived from maleic anhydride, which polymer becomes soluble in an alkaline developer under the action of an acid, (C) a compound capable of generating an acid upon exposure to high-energy radiation, and (D) an organic solvent,
wherein R 1a and R 1b are hydrogen or straight, branched or cyclic C 1 -C 10 alkyl, R 1a and R 1b may bond together to form a non-aromatic ring with the carbon atom to which they are attached, R 2 is hydrogen, methyl or trifluoromethyl, R 3 is hydrogen or an acid labile group, a1 and b1 are numbers satisfying 0<a1<1, 0<b1<1, and 0<a1+b1≦1.
2. A resist composition comprising (A) a polymer P1′ comprising repeat units of the following general formulae (1a), (1b) and (2a), (B) a polymer having a structure containing one or both of a lactone ring and a hydroxyl group, and/or a structure derived from maleic anhydride, which polymer becomes soluble in an alkaline developer under the action of an acid, (C) a compound capable of generating an acid upon exposure to high-energy radiation, and (D) an organic solvent,
wherein R 1a and R 1b are hydrogen or straight, branched or cyclic C 1 -C 10 alkyl, R 1a and R 1b may bond together to form a non-aromatic ring with the carbon atom to which they are attached, R 2 is hydrogen, methyl or trifluoromethyl, R 3 is hydrogen or an acid labile group, R 4a to R 4c are hydrogen or straight, branched or cyclic C 1 -C 10 alkyl, and a1, a2 and b1 are numbers satisfying 0<a1<1, 0<a2<1, 0<b1<1, and 0<a1+a2+b1≦1.
3. A resist composition comprising (A) a polymer P1″ comprising repeat units of the following general formulae (1a), (1b), (2a) and (2b), (B) a polymer having a structure containing one or both of a lactone ring and a hydroxyl group, and/or a structure derived from maleic anhydride, which polymer becomes soluble in an alkaline developer under the action of an acid, (C) a compound capable of generating an acid upon exposure to high-energy radiation, and (D) an organic solvent,
wherein R 1a and R 1b are hydrogen or straight, branched or cyclic C 1 -C 10 alkyl, R 1a and R 1b may bond together to form a non-aromatic ring with the carbon atom to which they are attached, R 2 is hydrogen, methyl or trifluoromethyl, R 3 is hydrogen or an acid labile group, R 4a to R 4c are hydrogen or straight, branched or cyclic C 1 -C 10 alkyl, R 5 is straight, branched or cyclic C 1 -C 10 alkyl, and a1, a2, b1 and b2 are numbers satisfying 0<a1<1, 0≦a2<1, 0≦b1<1, 0<b2<1, and 0<a1+a2+b1+b2≦1.
4. A resist composition comprising (A) a polymer P2 corresponding to a polymer P1-H comprising repeat units of the following general formulae (1a) and (2a′) wherein some or all of hydroxyl groups in formulae (1a) and (2a′) are protected with protective groups, (B) a polymer having a structure containing one or both of a lactone ring and a hydroxyl group, and/or a structure derived from maleic anhydride, which polymer becomes soluble in an alkaline developer under the action of an acid, (C) a compound capable of generating an acid upon exposure to high-energy radiation, and (D) an organic solvent,
wherein R 1a and R 1b are hydrogen or straight, branched or cyclic C 1 -C 10 alkyl, R 1a and R 1b may bond together to form a non-aromatic ring with the carbon atom to which they are attached, R 2 is hydrogen, methyl or trifluoromethyl, and a1 and b1 are numbers satisfying 0<a1<1, 0<b1<1, and 0<a1+b1≦1.
5. The resist composition of claim 1 , further comprising (E) a basic compound.
6. The resist composition of claim 1 , further comprising (F) a dissolution inhibitor.
7. A pattern forming process comprising the steps of (1) applying the resist composition of claim 1 onto a substrate to form a resist coating, (2) heat treating the resist coating and exposing it to high-energy radiation through a photomask, and (3) developing the exposed coating with a developer.
8. A pattern forming process comprising the steps of (1) applying the resist composition of claim 1 onto a substrate to form a resist coating, (2) heat treating the resist coating and exposing it to high-energy radiation from a projection lens through a photomask while holding a liquid between the substrate and the projection lens, and (3) developing the exposed coating with a developer.
9. A pattern forming process comprising the steps of (1) applying the resist composition of claim 1 onto a substrate to form a resist coating, (2) forming a protective coating onto the resist coating, (3) heat treating and exposing the coated substrate to high-energy radiation from a projection lens through a photomask while holding a liquid between the substrate and the projection lens, and (4) developing with a developer.
10. The process of claim 8 wherein the liquid is water.
11. The process of claim 7 wherein the high-energy radiation has a wavelength in the range of 180 to 250 nm.
12. A pattern forming process comprising the steps of (1) applying the resist composition of claim 1 onto a mask blank to form a resist coating, (2) heat treating and exposing the resist coating in vacuum to electron beam, and (3) developing with a developer.