L[subscript g] = 60 nm recessed In[subscript 0.7]Ga[subscript 0.3]As metal-oxide-semiconductor field-effect transistors with Al[subscript 2]O[subscript 3] insulator

Abstract

In this Letter, we report on sub-100 nm recessed In[subscript 0.7]Ga[subscript 0.3]As metal-oxide-semiconductorfield-effect transistors(MOSFETs) with outstanding logic and high-frequency performance. The device features ex-situ atomic-layer-deposition (ALD) 2-nm Al[subscript 2]O[subscript 3] layer on a molecular-beam-epitaxy (MBE) 1-nm InP layer and is fabricated through a triple-recess process. An L[subscript g] = 60 nm MOSFET exhibits on-resistance (R[subscript ON]) = 220 Ω-μm, subthreshold-swing (S) = 110 mV/decade, and drain-induced-barrier-lowering (DIBL) = 200 mV/V at V[subscript DS] = 0.5 V, together with enhancement-mode operation. More importantly, this device displays record maximum transconductance (g[subscript m_max]) = 2000 μs/μm and current-gain cutoff frequency (f[subscript T]) = 370 GHz at V[subscript DS] = 0.5 V, in any III-VMOSFET technology.