Backside layout design of Snapback-free RCIGBT with multiple-cell

—A backside layout design for multiple cell RCIGBT is proposed to suppress the snapback effect which happens in the turn-on process of RCIGBT in this paper. The internal operation mechanism of RCIGBT has been analyzed by device simulation, proving that our backside layout design works well. Reduction in the ratio of backside N+/P+ area as well as the N buffer doping density and increase in the number of cells in chip are all proved as useful methods in reducing snapback voltage. Although some novel RCIGBT structures have been proposed to eliminate the snapback effect, most of them have been based on a single cell structure, which is not sufficient for the analysis of RCIGBT. It’s more practical and feasible in production to simply optimize the backside layout design of N+, P+ short area with the multiple cell RCIGBT structure. Here we will report on the analysis of the snapback effect and the backside optimum layout design for the multiple cell RCIGBT.