SiO2/SiC interface improvements using an oxidized thin film of a-Si

摘要

A new technological approach using an oxidized thin film of amorphous Si (a-Si) to obtain a more stable SiO2/SiC interface is proposed. The flat band voltage (Vfb) instabilities are investigated using sequential capacitance - voltage (C-V) measurements and a reduction in VFB shift is observed for the oxidized a-Si MOS capacitor in comparison with as-oxidized (AO) sample. A Fowler-Nordeihm tunneling mechanism in MOS devices is identified from I-V characteristics. Both current density and breakdown voltage have been determined, a significant improvement in the case of oxidized a-Si sample being observed. A barrier height of 2.62 eV between SiC and SiO2 conduction band, close to the ideal value, is obtained using the proposed technology for MOS oxide.