Fabrication Process and Properties of Nb-InSb-Nb Planar Junction

A Nb-InSb-Nb planar junction with a normal layer of InSb thin film was fabricated by a new process. In this report, the details of the fabrication process and properties of the junction are discussed. The Nb-InSb-Nb junction fabricated using the new process showed a supercurrent. This means that there is no notable barrier, such as the Schottky barrier at the interface between Nb and InSb. The InSb film has a mobility of 500∼700 cm2/V·s, which is 17∼23 times larger than that of Si. This makes it possible to realize the superconductor-semiconductor-superconductor junction with a low carrier density of 1017 cm-3.