Enhanced Filed Limiting Rings for Improving Breakdown Voltage Stability

Due to the hole interface traps caused by extreme thermal and electrical stress, breakdown voltage (BY) walk-in and walk-out phenomenon has been widely researched. An improved field limiting rings (FLRs) edge termination with enhanced rings (E-rings) structure have been proposed in this paper, which achieves well static electrical parameters and advanced BY stability. TCAD simulation results indicate that the proposed structure behaves better voltage drops distribution among the three FLRs ring spaces for various surface hole traps. Since the surface electrical field and potential are modulated by the enhanced rings and additional ring, the decline BY caused by the trap effect could be reduced more than 30% without any extra photo etching cost and compatible with original manufacturing process.