A study of oxide reliability limitation on different field plate based termination techniques for SiC power devices

SiC is a promising material for future power semiconductor devices due to its superior material property. As an important edge termination technique for SiC devices, field plate termination techniques have the advantage of being simple with fabrication process and that it avoids defects induced reverse leakage current associated with implantation based JTE terminations. In this paper, various field plate termination techniques are systematically studied and results reveal that severe electric field crowding exits in the oxide at the metal termination, which will potentially cause reliability concern and limit device breakdown voltage. Oxide reliability issue for various field plate edge termination for the first time is explored in detail and new techniques are proposed to minimize field crowding in the dielectric material. Dielectric reliability concerns are alleviated and a relatively high percentage of ideal breakdown voltage is achieved with the proposed termination structure. The proposed structure is simple and can be a promising termination technology for SiC power semiconductor devices.