电荷共享效应的RESURF横向功率器件击穿电压模型

Breakdown Model of RESURF Lateral Power Devices Based on Charge-Sharing Effect

分析降低表面场(reduced surface field,RESURF)横向功率器件耐压机理,假定共享区电荷沿对角线分配给横向和纵向耗尽区,建立了一个新的RESURF横向功率器件击穿电压模型.该模型能准确描述漂移区全耗尽和不全耗尽情况下的耐压特性,并具有数学表达式简单以及物理概念清晰的优点.在此基础上,导出了一个新的RESURF判据,进而给出了一个用于指导器件设计的漂移区剂量上下限.解析结果与实验结果吻合较好,验证了击穿电压模型和RESURF判据的正确性.

A breakdown model for RESURF lateral power device is developed. Based on the analysis of the breakdown mechanism in RESURF lateral power device, charges in the drift region are allocated to lateral and vertical junctions along the diagonal of the sharing area. This model can be used to investigate breakdown characteristics of the device when the drift region is fully or partially depleted. Besides, the model provides simple expressions with clear physical concepts. A new RESURF criterion is also derived to quantitate the upper and lower limits, which is useful to the design of the structure parameters. General agreements exist between the modelin~ results and the reported experimental results.