Trap model for GaN RF HEMT power switch

RF GaN HEMTs were characterized as power switches using pulsed IV system. The devices exhibited current collapse and ON resistance modulation. These trap effects were highly dependent on off state quiescent drain bias voltages. At higher switch voltages, the output power was reduced due increase in the ON resistance and collapse of drain current. Traps located on the surface between gate and drain caused R_ON modulation while the traps in the bulk beneath the gate plate caused current collapse. A power HEMT model incorporating traps was developed and simulations correctly predicted knee walk out due to increase in the ON resistance and current collapse due to bulk traps.