The Schematics Design And Performance Investigation Of The Snapback-free IGBT With Lower Reverse Recovery Energy Loss

With the development of thin wafer process, lithography and implantation at the backside of FS-IGBT (Field-Stop Insulated Gate Bipolar Transistor) become a reality, then the concept of shorted-anode IGBT, which was proposed in the early 90's of the last century, is about to pick up again. The shorted-anode IGBT was also called RC-IGBT. However, the recent application of the RC-IGBT is limited in the soft-switching conditions, and the distribution of the current flowlines in the conventional RC-IGBT at reverse conduction was non-uniform, which led to local overheating and low reliability.In order to resolve the existing problems in the RC-IGBT, we investigate the characteristics about forward conduction?reverse on-state?switching-off?blocking state and reverse recovery process. Firstly, we discuss the the forward on-state voltage VCE and reverse on-state drop VF at various sizes of the P+-anode and N+-short. Then in order to conquer the problem of the conventional RC-IGBT in hard-switching conditions, in this paper, a novel cross-section of RC-IGBT cell featured lower reverse recovery energy loss Err has been proposed. At last, a new structure of the N+-short region in the RC-IGBT has been demonstrated, which can be used to eliminate the snapback phenomenon in the RC-IGBT.Compared to the conventional RC-IGBT, the reverse recovery energy loss Err?peak current Irr and reverse time trr of the proposed one is 48.7%, 25.9% and 35.7% lower, respectively. In addition, the cell pitch of the RC-IGBT employed the proposed N+-short region can be reduced to 20?m, which is less one- twentieth that of the conventional RC-IGBT.This paper is beneficial to facilitate the commercial use of the RC-IGBT in the hard-switching conditions. Most importantly, the proposed solutions may prompt the production of the RC-IGBT domestically as soon as possible.