一款800V VDMOS终端结构的设计

Design of 800V VDMOS termination structure

设计了一款800 V VDMOS终端结构,采用场限环(FLR)与场板(FP)相结合的方式,在场限环上添加多晶硅场板与金属场板,有效地降低了表面电场峰值。通过调整终端结构,在135μm的有效终端长度上实现了848 V的击穿电压,最大表面电场为2.34×105 V/cm,小于工业界判断器件击穿场强标准(2.5×105 V/cm),且电场分布比较均匀,终端结构的稳定性和可靠性高。

The termination structure of 800 V VDMOS was designed, which consists of field limiting ring （FLR） and field plate （FP）. The surface electric field peak value could be reduced effectively by adding poly silicon FP and metal FP on the FLR. By regulating the termination structure, the breakdown voltage 848 V is achieved with 135μm effective length on termination structure. The maximum value of surface electric field is 2.34×105 V/cm and less than the critical electric field intensity （2.5×105 V/cm） in the industry. The distribution of surface electric field peaks is relatively uniform, which increases the stability and reliability of the termination structure.