METAL-INSULATOR-SUPERCONDUCTOR FIELD-EFFECT-TRANSISTOR USING SRTIO3 YBA2CU3OY HETEROEPITAXIAL FILMS

Planar-type metal-insulator-superconductor field-effect-transistors (MISFET) were fabricated and their current modulation characteristics were investigated. The FET had a structure of Al-gate metal/(100)SrTiO3-gate insulator/(001)YBa2Cu3Oy-channel, where the oxide layers were grown by selective heteroepitaxy employing pulsed ArF excimer laser deposition. The FET gate was 10-mu-m long and 100-mu-m wide. Apparent field-effect modulation of drain current was seen in both the normal (T > T(c)) and superconducting (T < T(c)) states. In the superconducting state, not only the critical current but also flux-flow resistance were appreciably changed according to the applied gate voltage.