Theoretical Analysis of ON-State Performance Limit of 4H-SiC IGBT in Field-Stop Technology

Abstract

In this article, the ON-state performance limits of 4H-silicon carbide (SiC) IGBTs in field-stop technology are theoretically estimated for the first time and compared against silicon counterparts. The theoretical analysis is based on static modeling of a high-current p-i-n diode and the calculation results are examined with TCAD simulations. Owing to conductivity modulation effect, the ON-state losses of 4H-SiC IGBTs do not show any significant increase with the increase in breakdown voltage (BV). However, the large built-in potential of SiC poses an inherent limit on the reduction of ON-state voltage drop. Compared with 4H-SiC IGBTs, the silicon-based IGBTs exhibit superior ON-state performance limits within the BV range considered, although their drift layer thicknesses are ten times higher than that of 4H-SiC IGBTs. Therefore, silicon IGBTs remain as efficient technologies for enhancing high power conversion efficiency.