Resist composition and patterning process

1. A chemically-amplified negative resist composition comprising:

(A) a quencher containing an onium salt shown by the following formula (A-1);

(B) a base polymer containing repeating units shown by the following formulae (B1) and (B2); and

(C) a photo-acid generator which generates an acid,

wherein R 1 represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a hydroxy group, an amino group, a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms optionally containing a fluorine atom, a chlorine atom, a bromine atom, a hydroxy group, an amino group, or an alkoxy group, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, —NR S —C(═O)—R 8 , or —NR S —C(═O)—O—R 8 ; R 7 represents a hydrogen atom or a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms optionally containing a halogen atom, a hydroxy group, an alkoxy group, an acyl group, or an acyloxy group; R 8 represents a linear, branched, or cyclic alkyl group having 1 to 16 carbon atoms or alkenyl group having 2 to 16 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and optionally contains a halogen atom, a hydroxy group, an alkoxy group, an acyl group, or an acyloxy group; R 2 and R 3 each represent a hydrogen atom or a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms; Rf 1 and Rf 2 each independently represent a fluorine atom, or a trifluoromethyl group; R 4 , R 5 , and R 6 each independently represent a linear, branched, or cyclic alkyl group or oxoalkyl group having 1 to 12 carbon atoms, a linear, branched, or cyclic alkenyl group or oxoalkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group or aryloxoalkyl group having 7 to 12 carbon atoms, and some or all of hydrogen atoms of these groups are optionally substituted with a hydroxy group, a carboxyl group, a halogen atom, a cyano group, an amide group, a nitro group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and carbon atoms of these groups are optionally interposed by an ether group, an ester group, a carbonyl group, a carbonate group, or a sulfonic acid ester group; R 4 and R 5 optionally bond with each other to form a ring with a sulfur atom bonded to R 4 and R 5 ; “m” represents an integer of 1 to 5; “n” represents an integer satisfying 0<n<5-m; and “p” represents an integer of 1,

wherein R A represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; R 11 and R 12 each independently represent a halogen atom, an acyloxy group having 2 to 8 carbon atoms optionally halogen-substituted, an alkyl group having 1 to 6 carbon atoms optionally halogen-substituted, or an alkoxy group having 1 to 6 carbon atoms optionally halogen-substituted; A l represents a single bond or a linear, branched, or cyclic alkylene group having 1 to 10 carbon atoms and optionally having an ether bond interposed in a carbon-carbon bond; W 1 represents a hydrogen atom, a monovalent aromatic group optionally having a substituent, or an aliphatic monovalent hydrocarbon group having 1 to 10 carbon atoms optionally having an ether bond, a carbonyl group, or a carbonyloxy group interposed in a carbon-carbon bond; Rx and Ry each independently represent a hydrogen atom, an alkyl group having 1 to 15 carbon atoms optionally substituted with a hydroxy group or an alkoxy group, or a monovalent aromatic group optionally having a substituent, given that not both of Rx and Ry are hydrogen atoms simultaneously, and Rx and Ry optionally bond with each other to form a ring with a carbon atom bonded to Rx and Ry; t 1 represents 0 or 1; x 1 represents an integer of 0 to 2; “a” represents an integer satisfying 0<a<5+2x 1 -b; “c” represents an integer satisfying 0<c<5 + 2x 1 -d; and “b” and “d” each represent an integer of 1 to 3.

2. The chemically-amplified negative resist composition according to claim 1 , wherein the base polymer further contains at least one repeating unit selected from a repeating unit shown by the following formula (B3) and a repeating unit shown by the following formula (B4):

wherein R 13 and R 14 each independently represent a hydroxy group, a halogen atom, an acetoxy group, an alkyl group having 1 to 8 carbon atoms optionally halogen-substituted, a primary alkoxy group having 1 to 8 carbon atoms optionally halogen-substituted, a secondary alkoxy group having 2 to 8 carbon atoms, an acyloxy group having 2 to 8 carbon atoms optionally halogen-substituted, or an alkylcarbonyloxy group having 2 to 8 carbon atoms optionally halogen-substituted; and “e” and “f” each independently represent an integer of 0 to 4.

3. The chemically-amplified negative resist composition according to claim 1 , wherein the base polymer contains a repeating unit shown by the following formula (B5) and a repeating unit shown by the following formula (B6):

wherein R A , Rx, Ry, W 1 , “b”, and “d” are as defined above.

4. The chemically-amplified negative resist composition according to claim 2 , wherein the base polymer contains a repeating unit shown by the following formula (B5) and a repeating unit shown by the following formula (B6):

wherein R A , Rx, Ry, W 1 , “b”, and “d” are as defined above.

5. The chemically-amplified negative resist composition according to claim 1 , further comprising (D) a crosslinking agent.

6. The chemically-amplified negative resist composition according to claim 2 , further comprising (D) a crosslinking agent.

7. The chemically-amplified negative resist composition according to claim 3 , further comprising (D) a crosslinking agent.

8. The chemically-amplified negative resist composition according to claim 4 , further comprising (D) a crosslinking agent.

9. A resist patterning process using the chemically-amplified negative resist composition according to claim 1 , comprising steps of:

forming a resist film by using the chemically-amplified negative resist composition on a substrate to be processed;

irradiating the resist film with a high energy beam to form a pattern; and

developing the resist film by using an alkaline developer.

10. A resist patterning process using the chemically-amplified negative resist composition according to claim 2 , comprising steps of:

forming a resist film by using the chemically-amplified negative resist composition on a substrate to be processed;

irradiating the resist film with a high energy beam to form a pattern; and

developing the resist film by using an alkaline developer.

11. A resist patterning process using the chemically-amplified negative resist composition according to claim 3 , comprising steps of:

forming a resist film by using the chemically-amplified negative resist composition on a substrate to be processed;

irradiating the resist film with a high energy beam to form a pattern; and

developing the resist film by using an alkaline developer.

12. A resist patterning process using the chemically-amplified negative resist composition according to claim 5 , comprising steps of:

forming a resist film by using the chemically-amplified negative resist composition on a substrate to be processed;

irradiating the resist film with a high energy beam to form a pattern; and

developing the resist film by using an alkaline developer.

13. The resist patterning process according to claim 9 , wherein the high energy beam is an electron beam or an extreme ultraviolet ray with a wavelength of 3 to 15 nm.

14. The resist patterning process according to claim 10 , wherein the high energy beam is an electron beam or an extreme ultraviolet ray with a wavelength of 3 to 15 nm.

15. The resist patterning process according to claim 11 , wherein the high energy beam is an electron beam or an extreme ultraviolet ray with a wavelength of 3 to 15 nm.

16. The resist patterning process according to claim 12 , wherein the high energy beam is an electron beam or an extreme ultraviolet ray with a wavelength of 3 to 15 nm.