SUB-HALF-MICROMETER PSEUDOMORPHIC INP INXGA1-XAS/INP HEMT ESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.81) WITH VERY HIGH F(T) VALUES/

In the recent past, strained Al-free InP/InxGa1-xAs/ InP high electron mobility transistors (HEMT's) with x > 53% and L(G) greater than or e qual to 0.5 mu m have shown very good performance mainly caused by the exceptional transport properties of electrons in In-rich InxGa1-xAs-c hannel layers. In this letter we report about new results for highly s trained devices with L(G) < 0.5 mu m. Thereby, current gain cut-off fr equencies of f(T) = 100 GHz (130 GHz) for x = 74% and L(G) = 0.3 mu m at 300 K (80 K) were achieved, respectively, whereas HEMT's with x = 8 1% and L(G) 0.18 mu m reached f(T) = 131 GHz (152 GHz) at the same tem peratures, Moreover, the same devices showed off- and on-state drain-s ource breakdown voltages of V-Dsbr(OFF) = 10.5 and 5 V anti V-Dsbr(ON) = 6 and 4 V, respectively. The combination of good RF and breakdown p erformance prove the potential of Al-free InP-based HEMT's for power a pplications at mm-wave frequencies.