Superconducting device having an extremely thin superconducting channel formed of oxide superconductor material

摘要

A superconducting device comprises a substrate having a principal surface and a non-superconducting oxide layer having a similar crystal structure to that of the oxide superconductor, which has a projection at its center portion. A superconducting source region and a superconducting drain region formed of an alpha -axis oriented oxide superconductor thin film are positioned at the both sides of the projection of the non-superconducting oxide layer separated from each other and an extremely thin superconducting channel formed of a c-axis oriented oxide superconductor thin film is positioned on the projection of the non-superconducting oxide layer. The superconducting channel electrically connects the superconducting source region to the superconducting drain region, so that superconducting current can flow through the superconducting channel between the superconducting source region and the superconducting drain region. This superconducting device further includes a gate electrode through a gate insulator on the superconducting channel for controlling the superconducting current flowing through the superconducting channel. In the superconducting device the upper surfaces of the superconducting source region and the superconducting drain region have the same level as that of the superconducting channel.