Numerical analysis of reverse recovery characteristics of 4H-SiC p+–n−–n+ power diode with injection conditions

Abstract

Reverse recovery behavior of semiconductor power diode is usually involved in the operation of electrical equipment, which is mainly determined by the internal factor and external circuit of the device. In the present paper, the spatial–temporal distribution of minority carriers (MCs) in base region (BR) and waveforms of current and voltage in reverse recovery of p+–n−–n+ type 4H-SiC diode were numerically probed via an analytical model with injection conditions, of which parameters such as diffusion coefficient and length depend on the concentration of injection carriers. The storage time and the recovery time were evaluated. The results indicate that the current and voltage transient characteristics in reverse recovery process are affected by the width, concentration of majority carriers and lifetime of minority carriers in base region, also by the doped levels in anode and cathode, as well as by the forward current density and reverse biased voltage at initial state. The characteristic frequency was also influenced by these factors. These obtained consequences could guide for device optimized design and application.