High-Temperature Static and Dynamic Reliability Study of 4H-SiC Vertical-Channel JFETs for High-Power System Applications
Reliability of SiC devices is of critical importance in FET controlled devices for high-power system applications. The inherent physical properties of SiC are well-suited for semiconductor electronic devices. SiC power FETs and diode rectifiers have been demonstrated to operate over higher voltage and temperature ranges, have superior switching characteristics, as well as have die sizes nearly twenty times smaller than correspondingly rated silicon-based devices . This would enable large improvements on power system performance. Among the SiC power devices, SiC junction field-effect transistor (JFET) is the only controlled turn on/off SiC device that is free from gate oxidation and high-temperature metal-semiconductor Schottky barrier reliability issues. With the vertical-channel structure, SiC VJFETs enable a higher packing density, lower on resistance, and easier fabrication at reduced cost than other SiC power FETs having a pre-channel or lateral channel region . As the advantages of 4H-SiC VJFETs have been more and more recognized by today’s power industry, a long-term reliability of the SiC VJFETs at high temperatures needs to be demonstrated.