考虑场板边缘效应的SOI-pLDMOS表面电场模型及器件优化设计

Surface electrical field model of SOI-pLDMOS considering edge effect of field plate and optimization design

针对带有栅极场板的绝缘体上硅p型横向双扩散场效应晶体管(SOI-p LDMOS),提出了一种新型表面电场解析模型.相比于传统模型,该模型充分考虑了场板边缘效应对电场分布的影响,验证结果显示新模型能更好地符合Medici数值仿真结果.此外,基于所建立的器件表面电场模型,研究了栅极场板长度(包括多晶硅场板和金属场板)及漂移区掺杂浓度对器件表面电场分布和击穿特性的影响,进而对SOI-p LDMOS进行了优化设计.流片测试表明,所建立的新型表面电场解析模型能够很好地指导器件参数设计,实现了器件耐压和导通电阻的最佳折中.

A new surface electrical field analytical model is presented for the p-type lateral double diffusion MOS（ metal-oxide-semiconductor） transistor based on silicon on insulator（ SOI-pLDMOS） with gate field plate. Compared with the traditional analytical model,the proposed model fully considers the influence of the edge effect of field plate upon the electrical field distribution. The results show that the presented model accords with the Medici simulations better. In addition,based on the new analytical model,the effects of the length of the gate field plate（ including the polysilicon field plate and metal field plate） and the concentration of p-drift on electrical field distributions and breakdow n characteristics are researched. Also,a SOI-p LDMOS is optimally designed. The test results demonstrate that the new surface electrical field analytical model can guide the design of device parameters and realize the best compromise betw een the breakdow n voltage and on-resistance.