Uniformity improvement of linear power pHEMTs using a very high selective wet etching

The realization and characterization of Al0.22Ga0.78As/In0.22Ga0.78As/GaAs multifinger linear power pHEMTs, rising a citric acid selective wet etching for the gate recessing, are reported. A very high uniformity for both the drain current and pinch-off voltage values have been obtained. The linearit y is confirmed by a quasiflat profile of the transconductance and of the ma ximum available gain (MAG) over a wide gate source voltage. Power and inter modulation distortion measurements at 16 GHz have been performed. An IP3 va lue of 25 dBm has been obtained for a 2 x 75 mu m device. (C) 1999 John Wil ey & Sons, Inc.