EFFECT OF SURFACE INHOMOGENEITIES ON THE ELECTRICAL CHARACTERISTICS OF SIC SCHOTTKY CONTACTS

This paper reports analysis of the role of defects on the electrical c haracteristics of high-voltage 6H-SiC Schottky rectifiers. The measure d reverse leakage current of high-voltage Ti and Pt rectifiers was fou nd to he much higher than that predicted by thermionic emission theory and using a barrier height extracted from the C-Tb measurements. In t his paper, a model based upon the presence of defects at the 6H-SiC/me tal interface is used to explains this behavior, It is proposed that t hese defects result in lowering of the barrier height in the localized regions and thus, significantly affect the reverse I-V characteristic s of the Schottky contacts. The presence of electrically active defect s in the Schottky barrier area has been verified by EBIC studies.