Compound, positive resist composition and method for formation of resist pattern

A compound represented by a general formula (A-1) shown below:

• [wherein, in said formula (A-1), R′ represents a hydrogen atom or an acid dissociable, dissolution inhibiting group, and a plurality of R′ groups may be identical or different, provided that at least one of said plurality of R′ groups represents an acid dissociable, dissolution inhibiting group;
• R″ represents an alkyl group of 1 to 10 carbon atoms;
• R11 to R17 each independently represents an alkyl group of 1 to 10 carbon atoms or an aromatic hydrocarbon group, which may include a hetero atom within a structure thereof;
• g and j each independently represents an integer of 1 or greater, and k and q each represents an integer of 0 or greater, provided that g+j+k+q is not greater than 5;
• a represents an integer of 1 to 3;
• b represents an integer of 1 or greater, and l and m each independently represents an integer of 0 or greater, provided that b+l+m is not greater than 4;
• c represents an integer of 1 or greater, and n and o each independently represents an integer of 0 or greater, provided that c+n+o is not greater than 4;
• and A represents a group represented by a general formula (Ia) shown below, a group represented by a general formula (Ib) shown below, or an aliphatic cyclic group]
• [wherein, in said formula (Ia), R18 and R19 each independently represents an alkyl group of 1 to 10 carbon atoms or an aromatic hydrocarbon group, which may include a hetero atom within a structure thereof;
• and r, y and z each independently represents an integer of 0 or greater, provided that r+y+z is not greater than 41.

A positive resist composition, comprising a base material component (A) that exhibits increased alkali solubility under action of acid, and an acid generator component (B) that generates acid upon irradiation, wherein

• said base material component (A) comprises a compound (A1) represented by a general formula (A-1) shown below,
• [wherein, in said formula (A-1), R′ represents a hydrogen atom or an acid dissociable, dissolution inhibiting group, and a plurality of R′ groups may be identical or different, provided that at least one of said plurality of R′ groups represents an acid dissociable, dissolution inhibiting group;
• R″ represents an alkyl group of 1 to 10 carbon atoms;
• R11 to R17 each independently represents an alkyl group of 1 to 10 carbon atoms or an aromatic hydrocarbon group, which may include a hetero atom within a structure thereof, g and j each independently represents an integer of 1 or greater, and k and q each represents an integer of 0 or greater, provided that g+j+k+q is not greater than 5;
• a represents an integer of 1 to 3;
• b represents an integer of 1 or greater, and l and m each independently represents an integer of 0 or greater, provided that b+l+m is not greater than 4;
• c represents an integer of 1 or greater, and n and o each independently represents an integer of 0 or greater, provided that c+n+o is not greater than 4;
• and A represents a group represented by a general formula (Ia) shown below, a group represented by a general formula (Ib) shown below, or an aliphatic cyclic group]
• [wherein, in said formula (Ia), R18 and R19 each independently represents an alkyl group of 1 to 10 carbon atoms or an aromatic hydrocarbon group, which may include a hetero atom within a structure thereof, and r, y and z each independently represents an integer of 0 or greater, provided that r+y+z is not greater than 4].