功率半导体器件击穿特性及结终端结构参数研究

Breakdown Characteristics and Junction Termination Structural Parameters of Power Semiconductor Devices

根据功率半导体器件(如BJT、VDMOSFET等)的结终端结构特点,利用TCAD半导体器件仿真软件全面系统的分析了结终端高浓度扩散区结深及三种不同结终端保护结构(结终端延伸结构、浮空场限环结构及结终端刻蚀结构)参数对器件击穿特性的影响。仿真结果表明:对于终端高浓度扩散区,当表面浓度一定时,随着扩散区结深的增大,器件击穿电压呈现出先增大后减小的变化特点。PN结终端柱面结边缘区域的电场局部集中是导致器件击穿电压降低的主要因素。对于三种不同的结终端保护结构,均可有效地降低柱面结边缘电场强度,显著地改善器件的反向击穿特性。对比三种结终端保护结构,结边缘刻蚀结构对器件击穿特性的改善效果较好。

According to the characteristics of junction terminal structure of power semiconductor devices（Such as BJT,VDMOSFET,etc）. And then the influences of junction terminal high concentration diffusion region junction depth and three different junction terminal protection structure（junction terminal extension structure, floating field limit ring structure and the junction terminal etching structure）parameters on the breakdown characteristic of device are analyzed comprehensively and systematically by using TCAD semiconductor device simulation software. The simulation results show that the junction terminal high concentration diffusion region,when the surface concentration is a fixed value,with the increase of diffusion region junction depth,the change characteristics of device breakdown voltage present first increases and then decreases. And the cylindrical junction at the edge of the area junction local electric field concentration is the dominating factor for decreasing the breakdown voltage. For three different junction terminal protection structure, can effectively reduce the cylindrical junction edge electric field intensity,the reverse breakdown characteristics significantly improved. Comparing three junction terminal protection structure,junction edge etching structure is works best at improvement of reverse breakdown characteristic.