Multidielectrics for GaAs MIS devices using composition-graded AlxGa1−xAs and oxidized AlAs

Abstract

Metal‐insulator‐semiconductor (MIS) structures were prepared by dry thermal oxidation of an AlAs layer that had been grown on a composition‐graded Al_xGa_1−xAs layer on GaAs. The epitaxial layers were grown by molecular beam epitaxy. Capacitance‐voltage (C‐V) measurements of these MIS structures demonstrated the achievement of inversion behavior with essentially no hysteresis and flatband voltages ranging from 0 to 0.1 V, which correspond to a fixed interface charge density of less than 2×10¹⁰ cm⁻². It was also found that the stress developed between the oxide film and the epilayer was reduced in these MIS structures.