Fabrication and Optimization of a High-Reliability 700 V Super-Junction MOSFET with Segmented P-Buried RESURF Termination

In this work, we propose a 700 V super-junction MOSFET with segmented p-type buried RESURF (reduced surface field) layer (PBR) in the termination region. Due to the self-regulating effect of the RESURF structure and position of the PBR layer in the y-direction, we can obtain a more uniform surface electric field distribution and effectively alleviate the charge-imbalance issues in the termination region. Consequently, this results in a more stable breakdown voltage (BV) and enhances the reliability of the super-junction platform. Based on a multi-epitaxy/multi-implant platform, we conduct experiments with the optimized termination structure. The experimental devices demonstrate that BV of the proposed structure exceeding 750 V and specific on-resistance (R
ON,SP
) below 1.5 Ω·mm
²
, and the experimental results are in good consistence with the simulated results. The HTRB test results and shift curve of the experimental devices are also demonstrated in our work.