Processing and Characterization of III–V Compound Semiconductor MOSFETs Using Atomic Layer Deposited Gate Dielectrics

Abstract

We demonstrate III–V compound semiconductor (GaAs, InGaAs, and GaN) based metal-oxide-semiconductor field-effect transistors (MOSFETs) with excellent performance using an Al2O3 high-permittivity (high-κ) gate dielectric, deposited by atomic layer deposition (ALD). These MOSFET devices exhibit extremely low gate-leakage current, high transconductance, high dielectric breakdown strength, a high short-circuit current-gain cut-off frequency (f T) and maximum oscillation frequency (f MAX), as well as high output power and power added efficiency. ALD is a robust process that enables repeatability and manufacturability for compound semiconductor MOSFETs. In order to contribute to the fundamental understanding of ALD-grown high-κ/III–V gate stack quality, we discuss stack and interface formation mechanisms in detail for Al2O3 and HfO2 gate dielectrics on GaAs.