Ultrahigh-speed 0.5 V supply voltage In0.7Ga0.3As quantum-well transistors on silicon substrate

The direct epitaxial growth of ultrahigh-mobility InGaAs/InAlAs quantum-well (QW) device layers onto silicon substrates using metamorphic buffer layers is demonstrated for the first time. In this letter, 80 nm physical gate length depletion-mode InGaAs QW transistors with saturated transconductance g(m) of 930 mu S/mu m and f(T) of 260 GHz at V-DS = 0.5 V are achieved on 3.2 mu m thick buffers. We expect that compound semiconductor-based advanced QW transistors could become available in the future as very high-speed and ultralow-power device technology for heterogeneous integration with the mainstream silicon CMOS.