p-Channel Quantum-Well Heterostructure MI3 SFET

A p-channel heterostructure MISFET-like device based on a quantum well with an underlying impurity layer is reported for the first time. The device is based on an AlGaAs/GaAs heterostructure with a recessed-gate geometry and employs Zn-diffused refractory-metal contacts. The 4100 cm2/V-s hole mobility obtained in this inverted-interface structure at 77 K is comparable to that achieved in normal-interface AlGaAs/GaAs heterostructures. Transconductance and A'-factor values as high as 52 mS/mm and 140 mS/V - mm, respectively, are obtained at 77 K in p-channel FET's with 2.0-μm gate lengths and 6.0-μm source-drain spacings, representing state-of-the-art values for p-HFET's at similar dimensions.