3000-V 4.3-Ω . cm2 InAlN/GaN MOSHEMTs With AlGaN Back Barrier

This letter reports the fabrication of InAlN/GaN high-electron mobility transistors (HEMTs) with a three-terminal OFF-state breakdown voltage (BV) of 3000 V and a low specific on-resistance of 4.25 m Omega . cm(2). To reduce the drain-to-source leakage current in these devices, an AlGaN back barrier has been used. The gate leakage current in these devices is in the similar to 10(-10) A/mm range owing to the use of a SiO2 gate dielectric. This current level is more than six orders of magnitude lower than in Schottky-barrier HEMTs. The combination of an AlGaN back barrier, the high charge sheet density of InAlN/GaN HEMTs, and the low leakage due to the gate-dielectric layer allows for a figure-of-merit BV2/R-ON,R- (SP) of similar to 2.1 x 10(9) V-2 . Omega(-1) . cm(-2).