槽型SiC MPS二极管的优化设计

Optimized Design of SiC Trench MPS Diodes

提出一种具有低反向泄漏电流和低导通电阻的SiC MPS二极管,它利用刻槽注入P区的方法突破SiC中P型离子注入深度的限制,同时采用一种新型非均匀原胞拓扑结构提高单极电流。阻断时,槽底注入的P区对肖特基结电场起到更好的屏蔽作用,减小器件反向漏电流;开态时,增大的肖特基结面积使得器件导通电阻减小。

A SiC MPS diode with low reverse leakage current and low on-resistance is proposed.The method of etching trench followed by P＋ region implantation is used to break the limit of P-type ion implantation depth on SiC epitaxy.Besides,a novel topography of nonuniform cells is employed to increase its unipolar current.In the blocking state,the P＋ region underneath the trench can significantly reduce the electric field on the Schottky junction.Therefore,the reverse leakage current is reduced.In the on-state,the decrease of on-resistance is caused by enlarging the area of Schottky junction.