Preparation and properties of AlGaN/GaN MOSHFETs with MOCVD Al2O3 as gate oxide

The I-V and C-V measurements were used for characterization of AlGaN/GaN HFETs and MOSHFETs. Deposited Al₂O₃₁ gate oxide yielded an increase of the sheet carrier density from 6.9times 10¹² to 7.25 times 1O¹² cm^-2 and subsequent increase of the drain current density up to 40% and increase of the extrinsic transconductance up to 37%, respectively. The gate leakage current of 10^-5 A/mm at -10 V is about 3 orders of magnitude lower than that of HFETs. This results indicate the suitability of a thick Al₂O₃ gate oxide for improvement of electronic properties of GaN-based MOSHFETs