Very high voltage AlGaAs/InGaAs pseudomorphic power HEMTs

This paper reports the development of double recessed pseudomorphic GaAs High Electron Mobility Transistors (HEMTs) for high voltage operation. The GaAs-based power HEMT with 0.25 mu m gate-length exhibited a gate to drain breakdown voltage of 30 volts, a peak g/sub m/ of 510 mS/mm, and a maximum current density of 540 mA/mm. When biased to 14 volts on the drain, the 400 mu m wide HEMT delivered 505 mW (1.26 W/mm) output power at 4.5 GHz. This is the highest output power density and drain-source operating voltage ever reported for HEMT devices. The device also showed excellent 4.5 and 10 GHz power performance combination (power gain, power density, power-added efficiency) at V/sub ds/=8V. The significant extension of device drain bias range as well as increase in the product of current density and breakdown voltage were attributed to the adoption of channel recess using reactive ion etching.<>