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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

Downscaling of classical metal oxide semiconductor (MOS) devices resulted in a need to replace the gate oxide by high k dielectrics to keep the gate leakage under control. However, new device issues such as an uncontrollable shift in the threshold voltage in p-type MOS devices and a reduction in channel mobility were encountered. These issues can be overcome by the implementation of buried strained SiGe channels, grown by selective epitaxial growth, as demonstrated in this paper. The optimized high k gate fabrication scheme starts with the growth of a very thin oxide layer. Therefore, a Si cap layer is required because oxidation of SiGe leads to defects at the gate/channel interface. The Si growth rate is influenced by the underlying SiGe layer, during the deposition of the first atomic layers. Nevertheless, accurate thickness control of the Si cap is possible. The minimal required Si cap thickness and its dependence on Ge content in the underlying SiGe channel, for making high-quality dielectrics and maintaining low capacitive equivalent thickness, is extracted from charge pumping measurements, CV measurements and energy dispersive x-ray spectroscopy measurements. Device results demonstrate the successful implementation of buried SiGe channels in pMOS devices with high k gate dielectrics.

The pronounced high interfacial densities of states (Dit) commonly observed around the midgap energy of dielectric/GaAs interfaces are generally considered the culprit responsible for the poor electrical performance of the corresponding inversion-channel metal-oxide-semiconductor field-effect-transistors. In this work, comprehensive Dit spectra as the function of energy [Dit(E)] inside the In0.2Ga0.8As band gap were constructed by using the quasistatic capacitance-voltage and the temperature-dependent conductance method on n- and p-type ultrahigh vacuum (UHV)-Ga2O3(Gd2O3)/In0.2Ga0.8As and atomic-layer-deposited (ALD)-Al2O3/In0.2Ga0.8As metal-oxide-semiconductor capacitors. Unlike the ALD-Al2O3/In0.2Ga0.8As interface giving a Dit spectrum with a high midgap Dit peak, the UHV-Ga2O3(Gd2O3)/In0.2Ga0.8As interface shows a Dit spectrum that monotonically decreases from the valence band to the conduction band with no discernible midgap peak.