Optimization of the anti-parallel diode in an IGBT module for hard-switching applications

This paper presents a novel P-i-N diode which is suitable to be used as an anti-parallel diode in an IGBT module. It is shown that the switching performance of the module is significantly improved with the new diode structure, under hard-switching conditions. Diode performance in commercially available IGBT modules is studied under hard-switching conditions, both experimentally and using a finite element based device simulator. The device simulator is then used to study and compare the performance of the new diode structure with commercially available devices. It is shown that the new structure gives superior switching performance at the cost of a small increase in its on-state voltage drop. It is also shown that the switching characteristics of the new diode show a dramatic improvement over the conventional P-i-N diode at high temperatures.