No abstract

Atomic layer deposition (ALD) is considered an enabling technique for the deposition of dielectrics on sensitive surfaces such as germanium. Proper control of the interfacial layer between Ge and the high-κ layer has been shown to be crucial for obtaining good performance of Ge-based metal-oxide-semiconductor devices. In this work, we compare O3 - and normalH2O -based ALD of HfnormalO2 and normalAl2normalO3 , and report on the thickness and electrical quality of GenormalO2 passivation layers. The thickness of the interfacial layer depends on the oxidant used and affects the interface state density. A small degree of intermixing at the GenormalO2 /high-κ interface is observed for all ALD process conditions. The interface state density can be significantly reduced by annealing the Pt-gated capacitors in forming gas (normalH2∕normalN2) at 300°C . After annealing, the interface state density becomes almost independent of the thickness of the GenormalO2 passivation layer.

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 Al 2 O 3 /GaSb interface have been studied by in situ deposition of an Al 2 O 3 high-j 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 D it along the bandgap, these results point out an efficient electrical passivation of the Al 2 O 3 /GaSb interface. V