A LOW ON-RESISTANCE, HIGH-CURRENT GAAS POWER VFET

We have developed a new fabrication process for GaAs VFET's that resul ts in excellent performance in a 10 A prototype designed for switching in low voltage synchronous rectifier applications, The new fabricatio n process uses a buried carbon-doped GaAs gate structure for the gate electrodes and an epitaxial overgrowth step, We have demonstrated 10 A devices with 3.5 m of gate width and 1.5 mOhm of on-resistance (speci fic on-resistance of 84 mu Ohm - cm(2)), The device required a 0.5 mu m channel etched between 0.5 mu m gates placing stringent requirements on the gate side wall etch profile and epitaxial doping uniformity.