Resist composition and method of forming resist pattern

1. A resist composition comprising a base component (A) which exhibits changed solubility in an alkali developing solution under action of acid, an acid-generator component (B) which generates acid upon exposure, and a nitrogen-containing organic compound (D), which suppresses diffusion of the acid generated from the acid-generator component (B) upon exposure,

said nitrogen-containing organic compound (D) comprising a nitrogen-containing polymeric compound (D1) comprised of a structural unit (d0) containing a cyclic group represented by general formula (d0-1-0) shown below in the side chain thereof:

wherein each of R a and R b independently represents an alkyl group, a halogen atom, a halogenated alkyl group, a polar group or a polar group-containing group; each of R c and R d independently represents a hydrogen atom, an alkyl group, a halogen atom, a halogenated alkyl group, a polar group or a polar group-containing group; and R e represents a hydrogen atom, an alkyl group which may have a substituent, a monovalent aliphatic cyclic group which may have a substituent or a monovalent aromatic cyclic group which may have a substituent.

2. The resist composition according to claim 1 , wherein said structural unit (d0) is a structural unit derived from acrylate ester.

3. The resist composition according to claim 1 , wherein said nitrogen-containing polymeric compound (D1) further comprises a structural unit (d1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.

4. The resist composition according to claim 3 , wherein said nitrogen-containing polymeric compound (D1) further comprises a structural unit (d2) derived from an acrylate ester containing a lactone-containing cyclic group.

5. The resist composition according to claim 3 , wherein said nitrogen-containing polymeric compound (D1) further comprises a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.

6. The resist composition according to claim 1 , wherein said base component (A) is a base component (A′) which exhibits increased solubility in an alkali developing solution under action of acid.

7. The resist composition according to claim 6 , wherein said base component (A′) comprises a resin component (A1) comprised of a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.

8. The resist composition according to claim 7 , wherein said resin component (A1) further comprises a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.

9. The resist composition according to claim 7 , wherein said resin component (A1) further comprises a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.

10. A method of forming a resist pattern, comprising: using a resist composition of claim 1 to form a resist film on the substrate; conducting exposure of said resist film; and alkali-developing said resist film to form a resist pattern.

11. The resist composition according to claim 1 , wherein said acid-generator component (B) comprises an onium salt-based acid generator represented by general formula (b-1) or (b-2) shown below:

wherein R 1 ″ to R 3 ″, R 5 ″ and R 6 ″ each independently represents an aryl group or alkyl group,

wherein two of R 1 ″ to R 3 ″ in formula (b-1) may be bonded to each other to form a ring with the sulfur atom; and

R 4 ″SO 3 − is an anion moiety represented by general formula (b-7) shown below, with the proviso that at least one of R 1 ″ to R 3 ″ represents an aryl group, and at least one of R 5 ″ and R 6 ″ represents an aryl group,

X-Q 1 -Y 1 —SO 3 −   (b-7)

wherein Q 1 represents a divalent linkage group containing an oxygen atom; Y 1 represents an alkylene group of 1 to 4 carbon atoms which may have a substituent or a fluorinated alkylene group of 1 to 4 carbon atoms which may have a substituent; and X represents a hydrocarbon group of 3 to 30 carbon atoms which may have a substituent.

12. The resist composition according to claim 11 , wherein said onium salt-based acid generator is represented by general formula (b1-1) shown below:

wherein X represents a hydrocarbon group of 3 to 30 carbon atoms which may have a substituent;

Y 1 represents an alkylene group of 1 to 4 carbon atoms which may have a substituent or a fluorinated alkylene group of 1 to 4 carbon atoms which may have a substituent; A + represents an organic cation; Q 2 represents a single bond or an alkylene group; and n 10 represents 0 or 1.

13. The resist composition according to claim 12 , wherein said onium salt-based acid generator is represented by general formula (b1-1-1) shown below:

wherein Q″ represents an alkylene group of 1 to 5 carbon atoms, —O—,—S—,—O—R 94 — or —S—R 95 — (wherein each of R 94 and R 95 independently represents an alkylene group of 1 to 5 carbon atoms);

n 10 represents 0 or 1; A + represents an organic cation; p represents an integer of 1 to 3; v1represents an integer of 0 to 3; w1 represents an integer of 0 to 3; and R 6 represents a substituent.