  In this work, the electrical properties of Al2O3 films deposited by reactive
ion sputtering were investigated by means of morphological, chemical and
electrical characterizations. This insulating layer suffers of an electron
trapping that is mitigated after the rapid thermal annealing (RTA). The RTA
improved also the permittivity (up to 6{\epsilon}0), although the negative
fixed charge remains in the order of 1012cm-2. However, the temperature
dependent electrical investigation of the MOS capacitors demonstrates that the
room temperature Fowler-Nordheim electron barrier height of 2.37 eV lies
between the values expected for SiO2/4H-SiC and Al2O3/4H-SiC systems.

Applied Physics