  This work demonstrates the viability of scandium oxide deposition on silicon
by means of high pressure sputtering. Deposition pressure and radio frequency
power are varied for optimization of the properties of the thin films and the
ScOx-Si interface. The physical characterization was performed by ellipsometry,
Fourier transform infrared spectroscopy, x-ray diffraction and transmission
electron microscopy. Aluminum gate electrodes were evaporated for
metal-insulator-semiconductor (MIS) fabrication. From the electrical
characterization of the MIS devices, the density of interfacial defects is
found to decrease with deposition pressure, showing a reduced plasma damage of
the substrate surface for higher pressures. This is also supported by lower
flatband voltage shifts in the capacitance versus voltage hysteresis curves.
Sputtering at high pressures (above 100 Pa) reduces the interfacial SiOx
formation, according to the infrared spectra. The growth rates decrease with
deposition pressure, so a very accurate control of the layer thicknesses could
be provided.
