JPS6453476A - Superconducting three-terminal element and manufacture thereof - Google Patents

Abstract

PURPOSE:To minimize the length of superconducting current flow and to control the superconducting current effectively, by making the upper semiconductor layer between electrodes, or in a partial region thereof, insulated or of opposite conductivity type through ion implantation or convergent ion implantation and by making it thinner than the semiconductor layer in a superconducting electrode section. CONSTITUTION:The upper surface of a channel semiconductor is entirely insulated by ion implantation using superconducting electrodes of a source 1 and a drain 2 as mask, and a channel layer 3 which controls superconducting current is thinned. In this method, a surface conducting layer is not formed which has been a problem in conventional methods and therefore, superconducting current passes through the semiconductor channel layer without leakage on a surface conductive layer, thus allowing effective control of superconducting current. This method is effective for the length L of electrode spacing less than 0.1mum; however, for L more than 0.1mum, a part of the upper channel semiconductor is insulated by use of convergent ion implantation into thin the channel layer.