Electric device with grains and an insulating layer

摘要

An electric device comprises a crystalline film deposited on a substrate and an electrode formed on the film. The crystalline film consists of a number of colomnar crystal grown at right angles from the surface of the substrate. There are many grain boundaries passing through the crystalline film from the substrate surface to the electrode. The direct contact between the electrode and the grain boundaries is prevented by means of an insulating coating applied only to the portion of surfaces of the columnar crystals where the boundaries appear.