Influence of inserting AlN between AlSiON and 4H-SiC interface for the MIS structure

► AlSiON/4H-SiC and conventional thermal oxidized SiOx/SiC have interfacial roughness. ► Inserting AlN film between AlSiON and SiC decreases the roughness of SiC surface. ► The roughness of AlN/SiC interface is less than that of half of the SiOx/SiC. ► C-V characteristics on AlSiON/AlN/SiC are improved by depositing temperature of AlN. ► AlSiON/AlN/SiC structure is one of attractive MIS structures for SiC devices.