GaAs metal-oxide-semiconductor devices with a complex gate oxide composed of SiO2 and GaAs oxide grown using a photoelectrochemical oxidation method

Abstract

In this study, a SiO2/GaAs oxide bi-layer layer was used as the gate oxide in GaAs-based metal-oxide-semiconductor (MOS) devices. The GaAs oxide layer of the bi-layer layer was directly formed on the GaAs surface by using the photoelectrochemical (PEC) oxidation method. Some samples were thermally treated at 200 °C and 300 °C in O2 ambience for 30 min. The surface state density of the oxide/GaAs interface with and without GaAs oxide thermal treatment was 7.2 × 1011 and 7.9 × 1011 cm−2 eV−1, respectively. The GaAs MOS field effect transistors (MOSFETs) with the PEC-deposited GaAs oxide thermally treated showed an output current of 152 mA mm−1 at VDS = 2.4 V and VGS = 0 V and an extrinsic transconductance of 89 mS mm−1.