GaAs MOSFETs using Ga/sub 2/O/sub 3/(Gd/sub 2/O/sub 3/) as gate dielectric

Abstract

Growth of an oxide mixture, Ga/sub 2/O/sub 3/(Gd/sub 2/O/sub 3/), in ultra-high vacuum, on clean and ordered GaAs[100] surface has produced atomically smooth oxide/GaAs interfaces with a low interfacial density of states. Both enhancement-mode p- and n-channel GaAs metal oxide semiconductor field effect transistors (MOSFETs) on GaAs semi-insulating substrates with inversion were demonstrated using this novel oxide as the gate dielectric and a conventional ion-implant technology. Depletion-mode GaAs MOSFETs with accumulation were also fabricated. The Ga/sub 2/O/sub 3/(Gd/sub 2/O/sub 3/) films with thickness varying from 500 to 50 /spl Aring/ show a low leakage current density of 10/sup -9/ A/cm/sup 2/ at low gate bias up to 2.5 V, and electrical breakdown fields of >10 MV/cm.