INP-BASED HETEROSTRUCTURE FIELD-EFFECT TRANSISTORS WITH HIGH-QUALITY SHORT-PERIOD (INAS)(3M) (GAAS)(1M) SUPERLATTICE CHANNEL LAYERS/

InP-based heterostructure field-effect transistors (HFETs) incorporati ng an (InAs)(3m)/(GaAs)(1m) short-period superlattice (SPSL) subchanne l are compared to HFETs using a ternary In0.77Ga0.23As alloy with resp ect to transport and device performance. Room temperature Hall mobilit y of 13100 cm(2)/V . s was measured on a (InAs)(3)/(GaAs)(1) SPSL with a two-dimensional electron sheet density of 3.1x10(12) cm(-2), which are the highest mobilities in such a material system so far. Sheet res istances as low as 35 Omega(square), at 17 K confirm the high quality of the (InAs)(3)/(GaAs)(1) SPSL channel material resulting in high tra nsit and unilateral gain cut-off frequencies of 63 and 190 GHz, respec tively, in HFETs exhibiting gate lengths of 0.65 mu m. Nevertheless, a significant improvement compared to the ternary alloy could not be ve rified.