AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors using directly grown oxide layer

A photoelectrochemical oxidation method was used to directly grow oxide film on the Al_0.15Ga_0.85N as the insulation film of the AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs). The gate leakage current at reverse bias of V_GS= -7V is WnA. Even the reverse bias is V_GS=-60V, the leakage current is only 102 nA. An unity gain cutoff frequency (f_T) of 5.6 GHz and a maximum frequency of oscillation (f_max) of 10.6 GHz were measured. These electrical performances are much better than those of GaN-based conventional MES-HEMTs.