Patent ID: 7521171

Claim:
A positive photosensitive resin having an acid-labile protecting group which is dissociatable by the action of an acid to allow the resin to have higher solubility in an alkaline developing solution, which resin is a copolymer containing at least a recurring unit having a phenolic hydroxyl group and has, in the high-molecular main chain, a structure represented by the following general formula (1): (wherein X 1 and X 2 may be the same or different and are each independently a straight chain or branched chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group, and these groups may be substituted with straight chain or branched chain hydrocarbon of 1 to 6 carbon atoms or —O-hydrocarbon; Y 1 and Y 2 may be the same or different and are each independently a hydrogen atom, a straight chain or branched chain hydrocarbon group having 1 to 6 carbon atoms, a sulfur-containing hydrocarbon group, or an aromatic hydro-carbon group which may have a substituent; and two Zs may be the same or different and are each independently an oxygen atom or a sulfur atom).