Effect of Direct Nitridation of 4H-SiC Surface on MOS Interface States

Abstract

A nitride layer was formed on a SiC surface by direct nitridation in pure N2 or in NH3 diluted with N2. The SiO2 layer was deposited by the thermal decomposition of tetraethylorthosilicate (TEOS) on the nitride layer to form an MIS diode. The XPS analysis showed that the nitride layer was oxidized during the deposition process of SiO2. The direct nitridation was effective to reduce the interface state density between the insulating layer and 4H-SiC