Modeling of reverse recovery effect for embedded diode in SJ MOSFET

This investigation aims at developing a compact model for the embedded diode in Super-Junction MOSFETs applicable for more than 500V bias conditions. It is demonstrated that the reverse-recovery effect is different from the conventional stand-alone pin diode. The reason is the extension of the depletion at the additional p/n junction in the Super-Junction MOSFET under reverse bias applications. The depletion region prevents the current flow and thus forcing the rapid charge dissipation from the device. We have developed an embedded diode model on the basis of HiSIM-Diode originally developed for the conventional pin diode.

I. Introduction

Power electronics are getting more important to realize smart energy consumption. Here, an important task to utilize the power electronics successfully is to protect devices from the breakdown occurring occasionally due to very high current flow into the device during circuit operation. To protect the power device, a power diode is utilized together with an inductances as depicted in Fig. 1a [1]. Since the power diode sustains very high voltages, a huge amount of carriers are stored in the diode during the forward condition. It is known that these carriers cause huge current flows to the opposite direction of the forward current during switching off. The phenomenon of the opposite current flow is called the reverse recovery effect. This current causes a spike during the switching on the power device as depicted in Fig. 1b. This maximum spike current must be controlled to protect the power device from the breakdown as well.