EXTREMELY HIGH-GAIN 0.15-MU-M GATE-LENGTH INALAS/INGAAS/INP HEMTS

High electron mobility transistors (HEMTs) based on the InAlAs/InGaAs heterojunction grown lattice matched to InP were fabricated with 0.15-mu-m T-shaped gates. The use of an undoped InGaAs cap layer in the epitaxial structure leads to excellent gate characteristics and very high transistor gain. At 95 GHz, a maximum available gain of 13.6 dB was measured. A maximum frequency of oscillation f(max) of 455 GHz was obtained by extrapolating from 95 GHz at -6 dB/octave. This is the best reported gain performance for any transistor.