LOW-TEMPERATURE LOW-VOLTAGE OPERATION OF HEMTS ON INP

Pseudomorphic single recessed Al.48In.52As/Ga.30In.70As/AlInAs pseudom orphic HEMTs (PM-HEMT) on InP with planar doping and gatelength 0.2mum are investigated at cryogenic temperatures (50K) for their high frequ ency intrinsic transport properties at low drain bias voltage. Transie nt drain current measurements are compared with DC characteristics and show the evolution of trapping effects versus drain voltage. HF measu rements show that at low temperature drain current saturates at drain voltage as low as 0.5V with nearly maximum transconductance (almost-eq ual-to 800mS/mm) and very high intrinsic cut-off frequency (almost-equ al-to 190GHz). In these ultrashort gate HEMTs, cryogenic temperatures bring the best relative improvement of intrinsic device transport prop erties (almost-equal-to 60%) at very low drain voltages (0.5V).