VDMOS横向变掺杂终端的优化与设计  

Optimization and design of variable lateral doping termination for VDMOS

作　　者：赵磊[1] 冯全源[1] ZHAO Lei;FENG Quanyuan(Institute of Microelectronics,Southwest Jiaotong University,Chengdu 611756,China)

机构地区：[1]西南交通大学微电子研究所,四川成都611756

出　　处：《电子元件与材料》2018年第9期53-56,共4页Electronic Components And Materials

基　　金：国家自然科学基金重点项目(61531016);四川省科技支撑计划重点项目(2017GZ0110)

摘　　要：击穿电压是垂直双扩散场效应晶体管(VDMOS)最重要的参数之一,器件的耐压能力主要由终端决定,终端区耗尽层边界的曲率半径制约了击穿电压的提升。横向变掺杂(Variable Lateral Doping)技术是调整深阱杂质的注入开窗和掩膜间距,在终端形成一个渐变的P型轻掺杂区,使反向偏压下终端区耗尽层边界的曲率半径变大。通过计算机仿真软件Sentaurus TCAD设计了一种650 V横向变掺杂结构终端。仿真结果表明,横向变掺杂结构终端可以有效缩小芯片面积和提高击穿电压,横向变掺杂结构终端的反向击穿电压为700 V,终端长度为118μm。与有相同击穿电压的场限环结构终端相比,其终端长度减小了25. 8%。此外,工艺设计复杂,但设计方法可以作为实际制造的参考。The breakdown voltage is one of the most important parameters of the vertical double diffusion power MOS(VDMOS).The withstand voltage of the device is mainly determined by the terminal.However,radius of curvature at the edges of the depletion layer has important effect on breakdown voltage of VDMOS device.The variable lateral doping technology only needs to adjust the implantation window and mask spacing.P-type lightly doped region is formed in the termination.Radius of curvature at the edges of the depletion layer is increased on the reverse bias voltage.A 650 V variable lateral doping structure terminal was designed by computer simulation software Sentaurus TCAD.The simulation results show that the variable lateral doping structure can decrease the terminal area and improve the breakdown voltage.Its breakdown voltage is 700 V and termination length is 118μm.Compared with the field limiting ring terminal structure of VDMOS with the same breakdown voltage,the terminal length of the variable lateral doping structure is reduced by 25.8%.Besides,the process design is complex,but this design method can provide a theoretical guidance for the actual production.

关 键 词：垂直双扩散场效应晶体管(VDMOS) 场限环 横向变掺杂 击穿电压 终端 功率器件 

分 类 号：TN386[电子电信—物理电子学]