Characteristics of submicron-footprint TiO2 based AlGaN/GaN MOSHEMT on SiC substrate

AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors (MOSHEMTs) with thick (>30 nm), high-κ (TiO₂/NiO), submicron-footprint (0.4 μm) gate dielectric on SiC substrate are demonstrated, which are found to exhibit low gate leakage current (~ 1 nA/mm of gate periphery), high I_MAX (1 A/mm), and high drain breakdown voltage (188 V). The derived current gain cutoff frequency is 30 GHz (from S-parameter measurements). The output power density is 6.6 W/mm, and the associated power-added-efficiency is 46% at 2.5 GHz frequency and 50 V drain bias. This high performance submicron-footprint MOSHEMT is highly promising for microwave power amplifier applications in communication and radar systems.