THERMODYNAMICALLY STABLE P-CHANNEL STRAINED-LAYER ALGAAS/INGAAS/GAAS HETEROSTRUCTURE FIELD-EFFECT TRANSISTOR

Device characteristics of a thermodynamically stable p-channel, strained quantum-well heterostructure field effect transistor (HFET) are reported. The AlGaAs/InGaAs/GaAs material system was used to fabricate the p-channel HFETs with Al and In mole fractions of 0.20 and 0.18, respectively. Transconductances of 32 and 94 mS/mm were achieved at 300 and 77 K, respectively, for devices with 1.2 mum recessed gates. These numbers are comparable to InGaAs quantum-well, recessed gate pHFETs whose quantum-well thicknesses exceed the thermodynamic stability limit. These results have important implications for high performance self-aligned devices which require high-temperature processing.