Abstract: High breakdown enhancement mode gallium nitride (GaN) based high electron mobility transistors (HEMTs) with integrated slant field plates. These HEMTs have an epilayer structure comprised of AlGaN/GaN buffer. Before the formation of the gate electrode, a passivation layer is deposited, and then the opening for the gate is patterned. The passivation layer below the gate is etched using an etch condition that creates a slanted sidewalls. Then, the charge below the channel is removed either by Fluorine-based plasma treatment and/or by a recess etch. The gate metal is deposited with an angled rotation to form a gate structure with an inherent field plate with rounded edges.

Abstract: An enhancement mode High Electron Mobility Transistor (HEMT) comprising a p-type nitride layer between the gate and a channel of the HEMT, for reducing an electron population under the gate. The HEMT may also comprise an Aluminum Nitride (AlN) layer between an AlGaN layer and buffer layer of the HEMT to reduce an on resistance of a channel.