基于垂直双扩散金属氧化物(VDMOS)场效应晶体管终端场限环(FLR)与场板(FP)理论,在场限环上依次添加金属场板与多晶硅场板,并通过软件仿真对其进行参数优化,最终实现了一款700VVDMOS终端结构的优化设计。对比场限环终端结构,金属场板与多晶硅复合场板的终端结构,能够更加有效地降低表面电场峰值,增强环间耐压能力,从而减少场限环个数并增大终端击穿电压。终端有效长度仅为145μm,击穿电压能够达到855.0V,表面电场最大值为2.0×10-5V/cm,且分布比较均匀,终端稳定性和可靠性高。此外,没有增加额外掩膜和其他工艺步骤,工艺兼容性好,易于实现。
Based on the theory of field limiting ring (FLR) and filed plate (FP) ot vertical uouLn - fused metal oxide semiconductor (VDMOS) field effect transistor termination, the optimization design of 700 V termination structure was obtained, by gradually adding metal FP and poly silicon FP on the FLR, the parameters were optimized using the way of software simulation. Compared to the termination structure of FLR, and combined with both metal and poly silicon FP, the surface electric field peak value could be re- duced effectively, the blocking voltage ability between FLRs could be enhanced, and the number of FLR was reduced and the breakdown voltage of the termination was increased. The effective length of the termination was 145 μm, the breakdown voltage of the device can reach 855.0 V. The distribution of surface electric filed peaks was relatively uniform, and the maximum value of surface electric field was 2. 0×105 V/cm. Therefore, the stability and reliability of this termination could be greatly enhanced. Besides, without any additional masks and process flows, this termination can be more simply fabricated and has good compatibility.