一种600V高压超结VDMOS结构设计与优化

Design and Optimization of 600V High Voltage Super-Junction VDMOS

基于电荷补偿原理的超结VDMOS(Super-Junction VDMOS,SJVDMOS)器件,比传统的VDMOS具有更低的比导通电阻,更高的击穿电压.文中详细介绍了超结VDMOS元胞设计步骤,之后借助TCAD仿真对超结VDMOS的击穿电压和比导通电阻进行了深入优化,探究了电荷不平衡、漂移区厚度、衬底反向扩散以及表面结构等对击穿电压和比导通电阻的影响.对元胞结构的优化使得超结VDMOS由最初的击穿电压为587V,比导通电阻为7.27mΩ·cm2,优化到最终的击穿电压为662.5V,比导通电阻为6.85mΩ·cm2,性能得到明显改善.

Based on the charge compensation principle,the super junction VDMOS（Super-Junction VDMOS,SJVDMOS）device has lower specific on-resistance and higher breakdown voltage than the traditional VDMOS.This paper introduces the super junction VDMOS cell design steps in detail.The TCAD is used to simulate the breakdown voltage and the specific on-resistance of super-junction VDMOS.The effects of charge imbalance,drift zone thickness,substrate back diffusion and surface structure on the breakdown voltage and specific on-resistance are investigated.The optimization of cell structure improves the performance of the super junction VDMOS obviously.The initial breakdown voltage improves from 587 Vto 662.5 V,and the specific on-resistance declines from 7.27 mΩ·cm^2 to 6.85 mΩ·cm^2.