Self-Aligned Inversion-Channel In0.53Ga0.47As Metal–Oxide–Semiconductor Field-Effect Transistors withIn-situDeposited Al₂O₃/Y₂O₃ as Gate Dielectrics

In-situ ultrahigh-vacuum-deposited Y 2 O 3 2–3-monolayer-thick on freshly grown In 0.53 Ga 0.47 As with an Al 2 O 3 cap were employed as a gate dielectric. A low interfacial density of states of (8–9) × 10 11 eV -1 cm -2 near the midgap has been measured using the conductance method. The strong Y 2 O 3 /InGaAs interfacial bonding, revealed using X-ray photoelectron spectroscopy, enables attainment of an atomically smooth interface with 750 °C annealing. Low subthreshold swing of 97 mV/decade, high drain current of 1.5 mA/µm, high transconductance of 0.77 mS/µm, and field-effect mobility of 2,100 cm 2 V -1 s -1 were achieved in a self-aligned inversion-channel InGaAs metal–oxide–semiconductor field-effect-transistor of 1 µm gate length.