一种新型P沟道VDMOS复合耐压终端

Novel combined edge termination for P-channel VDMOS

针对终端结构耐压的提高,研究了高压P沟道垂直导电双扩散型场效应晶体管的场限环和场板复合耐压终端结构,提出了一种采用单N+偏移区场限环和多级场板复合的耐压终端结构.仿真发现,该结构能更有效地改善器件主结的边缘电场分布,从而提高了器件的整体击穿电压.根据以上理论,将该结构运用在一款大功率P沟道垂直导电双扩散型场效应晶体管器件上.经流片测试结果表明,该P沟道垂直导电双扩散型场效应晶体管器件样品的击穿电压为-90V,与仿真结果中主结击穿电压达到-91V有很好的吻合,证明了该结构设计的正确性.

This paper is focused on the improvement of the breakdown voltage for P-channel Vertical Double- diffuse MOSFET（VDMOS）, mainly on the structure that is combined with the field limiting ring and the field plate. Based on their basic theories, this paper presents a novel junction termination for P-channel VDMOS with a structure of an N＋ offset region field limiting ring and two multistep field plates. Simulation results have proved its effective improvement on the electric field distribution at the edge of the main junction, With these achievements, an --80V P-channel VDMOS is designed and fabricated using this structure. The test for the breakdown voltage of the manufactured sample devices has been conducted and experimental results turn out to be in good accord with the simulation results, demonstrating the validity of the design.