Triangular shaped defects limiting reverse blocking performance of 4H Silicon Carbide high power junction barrier Schottky devices

Abstract

In this study, we examined triangular defects (TD) present in 4H-SiC junction barrier Schottky devices (JBS) by means of I-V measurements, infrared (IR) microscopy, electron beam induced current (EBIC), and electroluminescence (EL). The structure of TD's was analyzed by Nomarski differential interference contrast microscopy (NDIC) and transmission electron microscopy (TEM). IR-microscopy images provide direct evidence that TD could cause a high localized leakage current under reverse bias. Structural analysis of a benign TD revealed that it contained a thin inclusion layer with a thickness in single nanometer range. This further strengthens the hypothesis that the breakdown is a consequence of the formation of a 3C and 4H interface.