An enlightening and feasible process concept for irradiated SJ-VDMOS to realize high-speed body diode and stable threshold voltage

In this paper, we have proposed an enlightening and feasible process concept for irradiated Super-Junction Vertical Diffusion Metal Oxide Semiconductor (SJ-VDMOS) to realize fast reverse recovery of its body diode and maintain the stable threshold voltage for the first time. Twice epitaxy is adopted in this process concept. The electron irradiation is performed after the first epitaxy, and then the second epitaxy is conducted. Silicon etching and p-pillar refilling will be done afterwards. The fast reverse recovery of body diode is obtained by introducing the deep energy levels in the drift region, and the stable threshold voltage (V
_TH
) can be achieved due to the p-body region and the gate oxide are not suffered from electron irradiation. Combining experimental results with simulated verification, this process concept presents a huge potential of realizing high reliability and high stability among irradiated devices.