Patent ID: 7976744

Claim:
A process for the preparation of a plane-parallel structure comprising at least one dielectric layer consisting of one or more oxides of a metal selected from groups 3 to 15 of the periodic table, which comprises the steps of: (a) applying a thin film of the dielectric material on a flexible belt, by passing the belt through an aqueous solution of a fluorine scavenger and one or more fluorine containing metal complexes which are the precursors of the desired metal oxide coating, which belt absorbs microwave radiation better than the solution; and subjecting said solution to microwave radiation to deposit the metal oxide onto said flexible belt, wherein the aqueous solution of the fluorine containing metal complex is added continuously in order that the metal oxide grows on the belt rather than precipitate into bulk of the reaction medium, wherein step (a) can optionally be repeated using different fluorine containing metal complexes to produce one or more metal oxide layers or a gradient of concentration of 2 different metal oxides across the thickness; (b) separating the resulting layer from the flexible belt as plane-parallel structures.