公开(公告)号：US20180026129A1

公开(公告)日：2018-01-25

申请号：US15602122

申请日：2017-05-23

Applicant: University of Electronic Science and Technology of China

Inventor： Min REN ,  Chi XIE ,  Jiaju LI ,  Ziqi ZHONG ,  Zehong LI ,  Jinping ZHANG ,  Wei GAO ,  Bo ZHANG

IPC: H01L29/78 ,  H01L21/306 ,  H01L29/40 ,  H01L29/06 ,  H01L29/10 ,  H01L29/417

CPC classification number: H01L29/7811 ,  H01L21/30604 ,  H01L29/0611 ,  H01L29/0638 ,  H01L29/0649 ,  H01L29/0661 ,  H01L29/0684 ,  H01L29/1079 ,  H01L29/1095 ,  H01L29/405 ,  H01L29/407 ,  H01L29/41741

Abstract: Edge termination structures for power semiconductor devices (or power devices) are disclosed. The purpose of this invention is to reduce the difficulty of deep trench etching and dielectric filling by adopting an inverted trapezoidal trench. In order to save the area of edge termination and get a high blocking voltage on condition that the angle between the sidewall of the trench and horizontal is large, fixed charges are introduced at a particular location in the trench. Due to the Coulomb interaction between the ionized impurity in the drift region and the fixed charges, the depletion region of the terminal PN junction can extend fully, which relieves the concentration of electric field there. Therefore, the edge termination can exhibit a high breakdown voltage near to that of the parallel plane junction with a smaller area and the reduced technical difficulty of deep trench etching and dielectric filling.