深槽型半超结VDMOS器件仿真研究

Simulation study of deep trench semi-superjunction VDMOS deviceLI Yao , GOU Henglu , SHEN Lihuan,NIU Ruixia,CHEN Wenshu,

摘要:

本文基于超结理论,设计了深槽型半超结垂直双扩散金属氧化物半导体场效应晶体管(DT-SSJ VDMOS),通过Silvaco TCAD仿真软件对其电学特性进行了仿真研究,并对比讨论了DT-SSJ VDMOS与深槽型VDMOS(DT VDMOS)及深槽型超结VDMOS(DT-SJ VDMOS)的电学特性。深沟槽的引入打破了栅氧化界面垂直电场高斯定律的限制,降低了栅氧化层峰值电场；相对于超结结构,半超结的引入降低了工艺复杂度,同时提升了器件稳定性。仿真结果表明,DT-SSJ VDMOS的击穿电压(BV)为1000V,比导通电阻(Ron,sp)为26.78 mΩ.cm2^{及品质因数}(FOM)为37.565 MW/cm2^。与DT VDMOS器件相比,DT-SSJ VDMOS的BV提高了100%,FOM提高了57%；与DT-SJ VDMOS器件相比,其Ron,sp降低了35.9%,FOM提高了5%,采用深沟槽和半超结结构,更好地折中了击穿电压和比导通电阻之间的矛盾,器件的整体性能也得到了提升。

Abstract:

Based on the super-junction theory, the deep trench semi-super-junction vertical double-diffused metal-oxide-semiconductor field-effect transistor (DT-SSJ VDMOS) was designed. The electrical characteristics of it were simulated and studied by Silvaco TCAD simulation software. And the electrical characteristics of DT-SSJ VDMOS were compared and discussed with those of the deep trench VDMOS (DT VDMOS) and the deep trench super-junction VDMOS (DT-SJ VDMOS). The introduction of the deep trench breaks the limitation of the Gaussian law of the vertical electric field at the gate oxide interface, and the peak electric field of the gate oxide layer is reduced. Compared with the super-junction structure, the introduction of the semi-super-junction reduces the process complexity and improves the device stability at the same time. The simulation results show that the breakdown voltage (BV) of DT-SSJ VDMOS is 1000 V, the specific on-resistance (Ron,sp) is 26.78 mΩ.cm2 and the figure of merit (FOM) is 37.565 MW/cm2. Compared with the DT VDMOS device, the BV of DT-SSJ VDMOS is increased by 100% and the FOM is increased by 57%. Compared with the DT-SJ VDMOS device, its Ron,sp is reduced by 35.9% and the FOM is increased by 5%. By adopting the deep trench and semi-super-junction structures, the contradiction between the breakdown voltage and the specific on-resistance is better compromised, and the overall performance of the device is also improved.