Self-Aligned Inversion-Channel In$_{0.53}$Ga$_{0.47}$As Metal–Oxide–Semiconductor Field-Effect Transistors withIn-situDeposited Al$_{2}$O$_{3}$/Y$_{2}$O$_{3}$ as Gate Dielectrics

In-situ ultrahigh-vacuum-deposited Y2O3 2–3-monolayer-thick on freshly grown In0.53Ga0.47As with an Al2O3 cap were employed as a gate dielectric. A low interfacial density of states of (8–9)×1011 eV-1 cm-2 near the midgap has been measured using the conductance method. The strong Y2O3/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 cm2 V-1 s-1 were achieved in a self-aligned inversion-channel InGaAs metal–oxide–semiconductor field-effect-transistor of 1 µm gate length.