MICROWAVE PERFORMANCE OF A DIGITAL ALLOY BARRIER AL(SB,AS)/ALSB/INAS HETEROSTRUCTURE FIELD-EFFECT TRANSISTOR

We demonstrate high-speed, digital alloy barrier-based, Al(Sb,As)/AlSb/InAs heterostructure field-effect transistors (HFET's) fabricated using a standard mesa process. Current gain cutoff frequencies f(T) of 38.5 GHz were extracted from the measured scattering parameters for devices with a 0.6-mum gate length and a 3-mum source-to-drain separation. A significant output conductance depressed f(max) to 40 GHz. The results demonstrate the feasibility and potential of InAs/AlSb-based HFET's for high-speed electronics applications.