Investigation of GaAs Layers Grown by Molecular Beam Epitaxy at Low Temperature

摘要

Over the three-year course of this program, the low-temperature-grown (LTG) GaAsand AlGaAs have been incorporated as the gate insulator or surface passivation in a variety of field-effect-transistors (FETs). The LTG GaAs used as the surface passivation layer in a metal-semiconductor FET (MESFET) with a novel overlapping gate structure increased the breakdown voltage by two folds compared to a regular MESFET. The LTG GaAs passivation also greatly improved the surface quality of the device, resulting in a reduced low-frequency noise and minimal frequency dispersions of the transconductance and the output resistance. The mechanisms for the improved breakdown voltage have been studied by computer simulation. Self-