Investigation and Fabrication of AlGaN/GaN MOS-HEMTs with Gate Insulators Grown by Photoelectrochemical Oxidation Method

Abstract

AlGaN/GaN MOS-HEMTs with gate insulators directly grown using photoelectrochemical (PEC) oxidation method were investigated. The gate length and the gate width is 1 μm and 50 μm, respectively. The drain-source saturation current (VGS=0 V) and the threshold voltage of AlGaN/GaN MOS-HEMTs is 580 mA/mm and -9 V, respectively. The maximum extrinsic transconductance is 76.72 mS/mm operated at VGS=- 5.1 V and VDS=10 V. The forward breakdown voltage and reverse breakdown voltage is 25 V and larger than -100 V, respectively. When the VGS=- 60 V and 20 V, the leakage current was 102 nA and 960 nA, respectively. The low frequency noise characteristics were also measured and studied. The Hooge′s coefficient estimated at VGS=0 V. When VDS is 10 V and 2 V at frequency of 100 Hz, the Hooge′s coefficient is 1.25×10-3 and 5.69×10-4, respectively.