Film-former composition

A film-former composition, comprising:

• (a) an organosilazane copolymer comprising a structural unit of the formula [I]:
• [R.sup.1 (CH.sub.2).sub.m ].sub.a R.sup.2.sub.b Si(NR.sup.3).sub.(4-a-b)/2 [I]
• and a structural unit of the formula [IV]:
• [R.sup.4 (CH.sub.2).sub.n ].sub.g R.sup.2.sub.h Si(NR.sup.3).sub.(4-g-h)/2 [IV]
• wherein R.sup.1 represents a perfluoroalkyl group, R.sup.2 and R.sup.3, which may be the same or different, each represent a hydrogen atom or a monovalent hydrocarbon group, R.sup.4 represents an acryloyl or methacryloyl group, a and g are each an integer of 1 to 3, b and h are each an integer of 0 to 2, such that (a+b) and (g+h) are each an integer of 1 to 3, and m and n are each an integer of 2 to 5, provided that the structural unit of formula [I] and the structural unit of formula are contained in such amounts that the molar content ratio of the perfluoroalkyl group (R.sup.1) to the total of the hydrogen atom or monovalent hydrocarbon group (R.sup.2) and the acryloyl or methacryloyl group (R.sup.4) satisfies the following equation:
• R.sup.1 /(R.sup.2 +R.sup.4)=from 99/1 to 50/50,
• (b) a photosensitizer soluble in an organic solvent, and
• (c) an organic solvent.