Properties of Al2O3 thin films deposited on 4H-SiC by reactive ion sputtering

Abstract In this work, the electrical properties of Al 2 O 3 films deposited by reactive ion sputtering were investigated by means of morphological, chemical and electrical characterizations. We observe that the electron trapping affecting the insulating layer is mitigated after a rapid thermal annealing (RTA) treatment. The RTA improved also the permittivity (up to 6e 0 ), although the negative fixed charge remains in the order of 10 12 cm −2 . However, the temperature dependent electrical investigation of the metal-oxide-semiconductor (MOS) capacitors demonstrates that the room temperature Fowler-Nordheim electron barrier height of 2.37 eV lies between the values expected for SiO 2 /4H-SiC and Al 2 O 3 /4H-SiC systems.