DIELECTRIC-BASE TRANSISTOR USING YBA2CU3O7-X/NDGAO3/SRTIO3 HETEROSTRUCTURES

This paper describes the fabrication and evaluation of dielectric-base transistors having high-T(c) YBa2Cu3O7-x electrodes with NdGaO3 low-permittivity barriers on SrTiO3 high-permittivity substrates. The YBa2Cu3O7-x/NdGaO3/SrTiO3 heterostructures were made by laser ablation. Nb base electrodes were sputtered on the back of the SrTiO3 substrate. The device showed transistor characteristics with voltage and current gains exceeding unity at 4.2 K. The collector current density was about 10 A/cm2 at a collector voltage of 20 V, four orders of magnitude larger than that obtained for devices having no artificial barriers.