Abstract: An oxide superconducting multilayered thin film structure having a laminated layer structure of oxide superconductor thin film layers and non-superconductor thin film layers constituted by a combination of material groups for making strain free interfaces among both thin film layers. For example, an oxide superconductor multilayered film constituted by a laminated layer structure where thin films of an oxide superconductor represented by the chemical formula of M'Ba.sub.2 Cu.sub.3 O.sub.7-.delta. (M'; a rare earth element of Nd, Sm, Eu or the like or an alloy of these, .delta.; oxygen depletion amount) and thin films of an oxide represented by the chemical formula of M*Ba.sub.2 Cu.sub.3 O.sub.7-.delta. (M*; an element of Pr, Sc or the like or an alloy of these, .delta.; oxygen depletion amount) are alternately stacked. The oxide thin films are thin films fabricated by a pulsed laser deposition process or a sputtering process. A Josephson device can be provided by using the multilayered film.

Abstract: A planar type semiconductor device having a high breakdown voltage, including a diffusion region of a P type formed in a semiconductor layer of an N type, a guard ring region of the P type formed in the semiconductor layer and surrounding the diffusion layer, and an insulating film covering the surface of the semiconductor layer between the diffusion and guard ring region. A field plate is provided which is kept at a potential equal to that of the diffusion region. The field plate covers the entire surface of that portion of the insulating film which is between the diffusion and guard ring regions.

Abstract: A photovoltaic device comprises a transparent substrate, an amorphous silicon layer structure of a p-i-n type formed on the substrate and comprised of a p-layer, i-layer and n-layer, and an electrode formed on the amorphous silicon layer structure, wherein either the p-layer and n-layer of the amorphous silicon layer structure, on which light is incident is constituted such that its optical forbidden band gap is greater on the i-layer side than on the substrate side.