Lg = 60 nm recessed In0.7Ga0.3As metal-oxide-semiconductor field-effect transistors with Al2O3 insulator

In this Letter, we report on sub-100 nm recessed In0.7Ga0.3As metal-oxide-semiconductor field-effect transistors (MOSFETs) with outstanding logic and high-frequency performance. The device features ex-situ atomic-layer-deposition (ALD) 2-nm Al2O3 layer on a molecular-beam-epitaxy (MBE) 1-nm InP layer and is fabricated through a triple-recess process. An Lg = 60 nm MOSFET exhibits on-resistance (RON) = 220 Ω-μm, subthreshold-swing (S) = 110 mV/decade, and drain-induced-barrier-lowering (DIBL) = 200 mV/V at VDS = 0.5 V, together with enhancement-mode operation. More importantly, this device displays record maximum transconductance (gm_max) = 2000 μs/μm and current-gain cutoff frequency (fT) = 370 GHz at VDS = 0.5 V, in any III-V MOSFET technology.