DEPLETION MODE GAAS METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT TRANSISTORS WITH GA2O3(GD2O3) AS THE GATE OXIDE

We have successfully fabricated depletion mode GaAs metal-oxide-semico nductor field effect transistors using Ga2O3(Gd2O3) as the gate oxide and an oxygen implant isolation technique. Growth of the device struct ure including the deposition of Ga2O3(Gd2O3) was performed in a multic hamber molecular beam epitaxy system. A 1 mu m x 100 mu m device shows excellent de and microwave characteristics with low output conductanc e. Complete pinchoff at V-g = -2.5 V and operation in the accumulation mode of up to V-g = 2.5V were measured. The maximum transconductance was 100 mS/mm, with a high drain current density of 315 mA/mm. Microwa ve testing yielded a f(T) of 14 GHz and a f(max) of 35 GHz. (C) 1998 A merican Vacuum Society.