Systematic Investigation on the Performance and Reliability of 4H-SiC MOSFETs With Nonkiller Epitaxial Morphological Defects

Epitaxial morphological defects in silicon carbide (SiC) MOSFETs can induce device failures. While chip probing (CP) methods can identify and distinguish many failed devices, some nonkiller epitaxial morphological defects often pass the initial screening, leading to early failures in practical applications. This study investigates the impact of SiC morphological defects on device performance, short-circuit (SC) reliability, and long-term reliability. Through a combination of experimental analysis and TCAD simulations, strong evidence is provided for the diverse effects of morphological defects on device performance. The results reveal that the Carrot-Defect significantly degrades the quality of the gate oxide, leading to premature failures in long-term reliability and SC tests. In contrast, the Triangle-Defect primarily affects the blocking capability of the device, while the SC performance of devices with such morphological defects that pass screening does not significantly deteriorate.