Demonstration of a 1200V Periodic Full-P Encapsulated 4H-SiC Trench MOSFET

作者：Jun Yuan, Zhijie Cheng, Fei Guo, Kuan Wang, Wei Chen, Yangyang Wu, Guoqing Xin, Zhiqiang Wang · 年份：2023 · DOI：10.1109/sslchinaifws60785.2023.10399703 · 被引用次数：7 · 研究领域：Silicon Carbide Semiconductor Technologies、Semiconductor materials and devices、HVDC Systems and Fault Protection

In this study, we have designed and fabricated a novel 1200 V periodic full-P encapsulated 4H-SiC trench MOSFET. The proposed SiC trench MOSFET substantially alleviates the tradeoff dilemma between breakdown characteristic and specific on-resistance, resulting in a larger design window that simultaneously achieves effective breakdown voltage, lower gate oxide layer electric field, and excellent on-state characteristics. Through numerical simulation and analysis, the design considerations and device performance of the proposed SiC trench MOSFET are demonstrated. The results show that the breakdown voltage of the proposed structure reaches 1675 V. When VDS= 1200 V, the electric field of the gate oxide layer is only 1.2 MV/cm. The periodic P+ buried layer encapsulated structure and the P-shield region at the bottom of the trench together form a good protection for the gate. At the same time, the most important N-Enrich region of the device is further optimized. It is concluded that when the width is 2 μm and the concentration is 1.0×1017cm-3, the specific on-resistance is only 3.0 mΩ·cm2. The BFOM is as high as 935 MW/cm2. The proposed structure greatly improves the compromise between breakdown characteristics and specific on-resistance. Moreover, first demonstration of the periodic full-P encapsulated SiC trench MOSFET prototype fabrication and SEM of two different cross sections are also detailed in this study.