Superconductor-Base Hot-Electron Transistor. II. Fabrication and Electrical Measurement

Publisher Website
Google Scholar
Abstract
Superconductor-base hot-electron transistors (Super-HETs) comprising n+-GaAs/Nb(or NbN)/α-InSb/Au multiplelayers were fabricated and electrical measurements were made at liquid-helium temperature. The observed hot-electron transport efficiency was as high as 80% for a device with a 200Å thick Nb base, close to the theoretical 90%. A device with a 600Å NbN base exhibited an efficiency of 60%. The sputtered InSb film served as a suitable collector barrier with a lower barrier height and an extremely reduced quantum mechanical reflection for incident hot-electrons. However, the space-charge limited current was still limited to the lower value, probably due to residual defects.