Carrier separation technique to optimize conductivity modulation in high voltage rectifiers

Abstract

Hybrid power rectifier structures like Junction Barrier Schottky (JBS) rectifier and Trench JFET Schottky rectifier (TJFET) employ a combination of minority and majority carrier conduction to offer the superior on-state and switching performance of Schottky rectifiers, along-with the superior reverse leakage and breakdown characteristics of PiN rectifiers. In such structures, it is important to properly tune the conductivity modulation to achieve the desired forward voltage drop (VF) and stored charge (QRR) trade-off for any given application. Some structures also employ lifetime control techniques to improve the switching speeds. This paper presents a new method based on carrier separation technique to properly quantify and optimize the amount of conductivity modulation in hybrid rectifier structures, and can be easily extended to other similar power device structures.