THIN FILM FORMING PROCESS

摘要

A process for producing an SOI substrate is disclosed which is useful for saving resources and lowering production cost. Further, a process for producing a photoelectric conversion device such as a solar cell is disclosed which can successfully separate a substrate by a porous Si layer, does not require a strong adhesion between a substrate and a jig, and can save resources and lower production cost. In a substrate having a porous layer on a nonporous layer and further having on the porous layer a layer small in porosity, the nonporous layer and the layer small in porosity are separated by the porous layer to form a thin film. A metal wire is wound around a side surface of the substrate, and a current is made to flow into the metal wire to generate a heat from the metal wire and transfer the heat preferentially to the porous layer, thus conducting the separation. The separated substrate is used for producing an SOI substrate and the separated nonporous Si layer is reutilized in a process of producing an SOI substrate.