Light-sensitive positive working composition containing a pisolfone compound

DETAILED DESCRIPTION What is claimed is: 1.
A positive working light-sensitive composition which comprises: (a) 10 to 95% by weight of a compound which has at least one acid-decomposable group and whose solubility in an alkaline developer increases by the action of an acid, (b) 0.
01 to 20% by weight of a disulfone compound represented by the formula (I): R.
sup.
1 --SO.
sub.
2 -SO.
sub.
2 --R.
sup.
2 (I) wherein R.
sup.
1 and R.
sup.
2 may be same or different and represent substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups or substituted or unsubstituted aryl groups, and (c) 3 to 85% by weight of a water-insoluble but alkaline watersoluble resin, wherein the optical density at 248 nm of 1 .
mu.
m thick coating of the composition is not more than 1.
4 and the optical density at 248 nm of the coating exposed to light of 248 nm is less than the optical density of the coating before exposed to light.
2.
The positive working light-sensitive composition of claim 1, wherein the compound which has at least one acid-decomposable group is a polymer having at least one structural unit represented by the following formulas (II) to (VI): ##STR7## wherein R.
sup.
3 represents hydrogen atom or an alkyl group, B represents --C(R.
sup.
4)(R.
sup.
5)(R.
sup.
6), --Si(R.
sup.
4)(R.
sup.
5)(R.
sup.
6) or --C(R.
sup.
7)(R.
sup.
8)--OR.
sup.
9, A represents B or --CO--O--B, Y represents a single bond or a divalent aromatic group, wherein R.
sup.
4, R.
sup.
5, R.
sup.
6, R.
sup.
7 and R.
sup.
8 may be same or different and represent hydrogen atoms, alkyl, cycloalkyl, alkenyl or aryl groups, and R.
sup.
9 is an alkyl or an aryl group, provided that at lest two of R.
sup.
4 to R.
sup.
6 are not hydrogen atoms and two of R.
sup.
4 to R.
sup.
6 or two of R.
sup.
7 to R.
sup.
9 may combine to form a ring.
3.
The positive working light-sensitive composition of claim 1, wherein the compound which has at least one acid-decomposable group is selected from the group consisting of poly(p-t-butyl carbonyloxy styrene), poly[N-(t-butoxycarbonyl)maleimide-costyrene], poly[N-(p-t-butoxycarbonyloxyphenyl)maleimide-costyrene], poly(t-butyl p-vinylbenzoate), poly(t-butyl methacrylate, poly(2-cyclohexenyl methacrylate), poly(2-cyclopropyl-propyl methacrylate) and poly(2-phenyl-propyl methacrylate), poly(p-trimethylsiloxy styrene), poly(p-t-butoxy styrene), poly(p-2-cyclohexenyloxy styrene), poly(p-2-pyranyloxy styrene), poly(silyl methacrylate), poly phthaldehydes and polycarbonates