Structural and Electrical Properties of Fully Strained (in,ga)as Field Effect Transistors with in Situ Deposited Gate Stacks

Metal-oxide-semiconductor field-effect transistors (MOSFETs) were fabricated with amorphous Al2O3 and HfO2/SiOx–Si gate stacks, grown by molecular beam deposition. As and In oxides were observed at the Al2O3/In0.17Ga0.83As interface, whereas no oxides were detected on the Si-passivated In0.17Ga0.83As surface after HfO2 deposition. Traces of As were found in both gate stacks. Si-passivated MOSFETs, with a drain current of 2.8×103 μA/mm at Vg−Vt=2.0 V, Vd=1.0 V, Ion/Ioff=1×107, and inverse subthreshold slope of 98–120 mV/decade, show superior performance with respect to devices without Si interlayer.