Investigation and Analysis of AlGaN MOS Devices with an Oxidized Layer Grown Using the Photoelectrochemical Oxidation Method

A photoelectrochemical oxidation method was used to directly oxidize an AlGaN layer as the oxide layer of metal-oxide-semiconductor (MOS) devices. The crystal phases of the oxide films were analyzed by X-ray diffraction (XRD) measurement. The oxide films have a better stability and crystallization after annealing in ambient at for . The binding configurations of the oxide films were analyzed by X-ray photoelectron spectroscopy (XPS). According to the results of XPS, XRD, and secondary ion mass spectrometry (SIMS) measurements, the main components of the oxide films consist of and . The average interface state density between the oxidized AlGaN layer and AlGaN semiconductor is . The leakage current of resultant MOS devices with a thick oxide layer is and at 5 and , respectively. The breakdown field is and at breakdown voltage of 10 and , respectively.