Direct comparison of silicon carbide and silicon diode avalanche shaper in multi-pulse applications

Abstract

This paper compares the pulse shaping characteristics of SiC and Si Diode Avalanche Shaper (DAS) under quasi-uniform triggering with the help of Technology Computer-Aided Design (TCAD) software. Under the same static breakdown voltage (VSB), the opening speed of SiC DAS does not show obvious advantages over that of Si DAS. With the same device structure, SiC DAS has a higher breakdown voltage than Si DAS, so it has a faster dV/dt in the triggering process. In addition, compared to Si, SiC DAS delayed breakdown voltage (VDB) is less affected by the input pulse rise rate. This is because the SiC DAS avalanche generation rate is more sensitive to the device voltage in the vicinity of VDB. Then, the multi-pulse operating characteristics of SiC and Si DAS with the same VSB were compared by continuously triggering the SiC and Si DAS 50 times at the 1 MHz frequency. It is revealed that the VDB of the SiC DAS is low but has excellent multi-pulse consistency. At the same time, under multi-pulse operation, the temperature rise speed of SiC DAS is slow, and the temperature distribution in the device is more uniform. It can be concluded that SiC DAS has significant advantages in high voltage and multi-pulse shaping.