GaSb molecular beam epitaxial growth on p-InP(001) and passivation with in situ deposited Al2O3 gate oxide

The integration of high carrier mobility materials into future CMOS generations is presently being studied in order to increase drive current capability and to decrease power consumption in future generation CMOS devices. If III–V materials are the candidates of choice for n-type channel devices, antimonide-based semiconductors present high hole mobility and could be used for p-type channel devices. In this work we first demonstrate the heteroepitaxy of fully relaxed GaSb epilayers on InP(001) substrates. In a second part, the properties of the Al2O3/GaSb interface have been studied by in situ deposition of an Al2O3 high-κ gate dielectric. The interface is abrupt without any substantial interfacial layer, and is characterized by high conduction and valence band offsets. Finally, MOS capacitors show well-behaved C–V with relatively low Dit along the bandgap, these results point out an efficient electrical passivation of the Al2O3/GaSb interface.