Coating composition and method for forming thin film on substrate using same

A method for applying a coating composition to a substrate with a reverse roller coater so as to form a thin film on the substrate and then for baking the thin film so as to transform the thin film into a metal oxide film, the method being characterized in that the coating composition comprises:

• 0.1-10 wt % of at least one organic metal compound on a metal oxide basis, said at least one organic metal compound being selected from the group consisting of metal alkoxides, metal acetylacetonates and metallic soaps;
• and
• at least one organic solvent,
• wherein said coating composition has a viscosity which is in a range from 0.1 to 100 centipoises;
• wherein the method comprises the sequential steps of:
• (a) applying the coating composition to the substrate with the reverse roller coater so as to form a first thin film on the substrate:
• (b) drying the first thin film at a temperature not higher than 400.degree. C.;
• (c) applying the coating composition to the first thin film with the reverse roller coater so as to form a second thin film on the first thin film;
• (d) drying the second thin film at a temperature not higher than 400.degree. C.;
• and
• (e) baking the first and second thin films at a temperature not lower than 400.degree. C. so as to respectively transform the first and second thin films to first and second metal oxide films.