HIGH-PERFORMANCE DOUBLE PULSE DOPED PSEUDOMORPHIC ALGAAS INGAAS TRANSISTORS GROWN BY MOLECULAR-BEAM EPITAXY

Double pulse doped AlGaAs/InGaAs pseudomorphic high electron mobility transistors have been grown by molecular-beam epitaxy on GaAs substrates. Hall mobilities in excess of 7100 cm2/V s at 300 K and 25 000 cm2/V s at 77 K are obtained with a sheet density of 3 x 10(12) cm-2. Photoluminescence measurements indicate that two electronic subbands are occupied, and the subband energies are determined. The doping pulses are resolved in secondary ion mass spectrometry measurements. Using a double recess process, transistors have been fabricated that have produced state of the art microwave performance. At 10 GHz a 1.2 mm device has simultaneously achieved a power added efficiency of 70%, output power of 0.97 W, and gain of 10 dB.