HIGH-PERFORMANCE, 0.1 MU-M INALAS INGAAS HIGH-ELECTRON-MOBILITY TRANSISTORS ON GAAS/

This letter describes the material characterization and device test of InAlAs/InGaAs high electron mobility transistors (HEMT's) grown on Ga As substrates with indium compositions and performance comparable to I nP-based devices. This technology demonstrates the potential for lower ed production cost of very high performance devices. The transistors w ere fabricated from material with room temperature channel electron mo bilities and carrier concentrations of mu = 10000 cm(2)/Vs, n = 3.2 x 10(12) cm(-2) (In = 53%) and mu = 11 800 cm(2)/Vs, n = 2.8 x 10(12) cm (-2) (In = 60%). A series of In = 53%, 0.1 x 100 mu m(2) and 0.1 x 50 mu m(2) devices demonstrated extrinsic transconductance values greater than 1 S/mm with the best device reaching 1.074 S/mm. High-frequency testing of 0.1 x 50 mu m(2) discrete HEMT's up to 40 GHz and fitting o f a small signal equivalent circuit yielded an intrinsic transconducta nce (g(m, i)) of 1.67 S/mm, with unity current gain frequency (f(T)) o f 150 GHz and a maximum frequency of oscillation (f(max)) of 330 GHz. Transistors with In = 60% exhibited an extrinsic g(m) of 1.7 S/mm, whi ch is the highest reported value for a GaAs based device.