Over 1500 V/2 A operation of GaN RESURF-MOSFETs on sapphire substrate

A GaN reduced surface field (RESURF) metal oxide semiconductor (MOSFET) on a sapphire substrate is fabricated. The n−-type RESURF zone was formed by a Si ion implantation technique. The n+- and n−-type GaN was activated at 1260°C for 30 s in ambient Ar. The sheet carrier densities (activation ratio) of n+- and n−-GaN were ∼3.0×1015 (∼100%) and 1.1×1012 cm−2 (1.8%), respectively. As a result, more than 1500 V and 2 A operation of the GaN RESURF MOSFETs is achieved with a channel length of 4 µm, a channel width of 150 mm, and the RESURF length of 20 µm.