Light-sensitive composition

A positive working photosensitive composition which comprises:

• (a) 0.5 to 80% by weight, based on the total weight of solids in the composition, of a compound which has (i) at least one group capable of being decomposed by an acid, said group being selected from the group consisting of tertiary alkyl ether groups, tertiary alkyl ester groups and tertiary alkyl carbonate groups, (ii) a molecular weight of not more than 1,200, and (iii) a boiling point of not less than 150.degree. C.;
• (b) 0.01 to 20% by weight, based on the total weight of solids in the composition, of a disulfone compound represented by the following formula (I):
• R.sup.1 --SO.sub.2 --SO.sub.2 --R.sup.2 (I);
• wherein R.sup.1 and R.sup.2 independently represent a substituted or unsubstituted alkyl, alkenyl or aryl group;
• and
• (c) 5 to 99.49% by weight, based on the total weight of solids in the composition, of a resin insoluble in water and soluble in an alkaline water, wherein a film of the composition having a thickness of 1 .mu.m has an optical density determined at 248 nm of not more than 1.4 before exposure to light and the optical density of the composition determined at 248 nm is reduced by exposure to light of 248 nm,
• wherein the compound of the component (a) is selected from the following compounds:
• ##STR7## wherein A represents a hydrogen atom, ##STR8## and B represents a group A or --CO--O--A, provided that at least one of the groups A and B present in a single molecule is a group other than hydrogen.