Positive photosensitive composition

A positive photosensitive composition comprising (A) an acid generator that generates an acid upon irradiation of an actinic ray or radiation, (B) a side chain type resin that has a monocyclic or polycyclic alicyclic hydrocarbon structure and is decomposed by the action of an acid to increase solubility in an alkali developing solution, and (C-2) a basic compound containing a substituted or unsubstituted aliphatic hydrocarbon group having not less than 8 carbon atoms;

• wherein the side chain type resin of component (B) consists of acrylate repeating units and/or methacrylate repeating units;
• the resin of component (B) contains at least one repeating unit selected from a repeating unit having a partial structure including an alicyclic hydrocarbon represented by formula (pI), (pII), (pIII), (pIV), (pV) or (pVI) described below:
• wherein R11 represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group;
• Z represents an atomic group necessary for forming an alicyclic hydrocarbon group together with the carbon atom;
• R12 to R16 each independently represent a straight chain or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R12 to R14, and either R15 or R16 represents an alicyclic hydrocarbon group;
• R17 to R21 each independently represent a hydrogen atom, a straight chain or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R17 to R21 represents an alicyclic hydrocarbon group, and either R19 or R21 represents a straight chain or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group;
• and R22 to R25 each independently represent a straight chain or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R22 to R25 represents an alicyclic hydrocarbon group, or R23 and R24 may be combined with each other to form a ring;
• and
• the resin of component (B) contains at least one repeating unit having a group represented by any one of the following formulae (V-1) to (V-4):
• wherein R1b, R2b, R3b, R4b and R5b, which may be the same or different, each represents a hydrogen atom, an alkyl group which may be substituted, a cycloalkyl group which may be substituted or an alkenyl group which may be substituted, or two of R1b, R2b, R3b, R4b and R5b may be combined with each other to form a ring.