Patent ID: 8080361

Claim:
A positive photosensitive composition comprising: a resin (A) whose dissolution rate in an alkaline developing solution increases by the action of an acid, the resin (A) containing an acid decomposable repeating unit represented by a general formula (I), an acid nondecomposable repeating unit represented by a general formula (II), and a lactone group-containing repeating unit; and a compound (B) capable of generating an acid upon irradiation with one of active rays and radiations: wherein Xa 1 represents one of a hydrogen atom, an alkyl group, a cyano group and a halogen atom, A 1 represents one of a single bond and a divalent connecting group, ALG represents an acid leaving hydrocarbon group, Xa 2 represents one of a hydrogen atom, an alkyl group, a cyano group and a halogen atom, A 2 represents one of a single bond and a divalent connecting group, ACG represents an acid nonleaving hydrocarbon group composed of only carbon atoms and hydrogen atoms, ACG in the general formula (II) has a polycyclic hydrocarbon structure, and ALG in the general formula (I) does not have a polycyclic hydrocarbon structure, and the acid decomposable repeating unit represented by the general formula (I) is an acid decomposable repeating unit represented by a general formula (I-1): wherein Xa 1 represents one of a hydrogen atom, an alkyl group, a cyano group and a halogen atom, and Rx 1 to Rx 3 each independently represents a linear or branched alkyl group, or a monocyclic alkyl group, and at least two of Rx 1 to Rx 3 may be taken together to form a monocyclic alkyl group, provided that at least one of Rx 1 to Rx 3 represents a monocyclic alkyl group, or at least two of Rx 1 to Rx 3 are taken together to form a monocyclic alkyl group.