Method for manufacturing a superconducting device having an extremely thin superconducting channel

摘要

The invention relates to a method of manufacturing a superconducting device, which comprises the steps of forming on a principal surface of a substrate a non-superconducting oxide layer having a similar crystal structure to that of a c-axis oriented oxide superconductor thin film and a flat-top projection at its center portion, forming a c-axis oriented oxide superconductor thin film having an extremely thin thickness on the non-superconducting oxide layer so as to form a superconducting channel on the projecting portion of the non-superconducting oxide layer, forming an insulating layer on the c-axis oriented oxide superconductor thin film so as to form a gate insulating layer on the superconducting channel, and forming an a-axis oriented oxide superconductor thin film so as to form a superconducting source region and a superconducting drain region of which upper surfaces have the same level as that of the superconducting channel. The projecting portion of the non-superconducting oxide layer is preferably formed by a lift-off process using a lift-off layer formed of a CaO layer covered with a Zr layer which is removed by utilizing water and the following reaction: CaO+H2O->Ca(OH)2.