Hybrid Termination With Wide Trench for 4H-SiC Super-Junction Devices

Termination design for 4H-SiC super-junction devices based on “trench-etching and implantation” technology, has been discussed through 3D numeric simulations and experiments. It is found that the existing design concept of super-junction termination extension (SJTE) structure is no longer capable of blocking high voltage due to the hole accumulation on the trench sidewall. In order to provide sufficient protection for the device edge, a novel device structure, i.e., hybrid termination of wide trench and SJTE (WT-SJTE), is proposed. With such WT-SJTE structure, the simulated device breakdown voltage can be improved from 700V to 800V. Furthermore, through the narrow termination mesa design, as predicted by numeric simulations, a noticeable improvement were measured, and a breakdown voltage of 960V was experimentally demonstrated. These results show the effectiveness of the WT-SJTE with such narrow termination mesa design.