Buried p-gate heterojunction field effect transistor

A buried p(+)-AlGaAs gate AlGaAs/InGaAs/AlGaAs double heterostructure field effect transistor (FET) (p-gate HFET) operating in enhancement mode has be en successfully fabricated using the Zn-diffusion technique. A low on-resis tance of 1.6 Ohm mm and a high gate built-in voltage of 1.5V with a maximum transconductance of 420mS/mm were obtained for a 0.8 mu m gate device. The buried p-gate HFET is promising for power-FET applications which require l ow distortion, high efficiency and positive bias operation.