A field limiting ring termination structure with a p type corrugated resistance region
A field limiting ring termination, designed for 3.3 kV high voltage fast and soft recovery diode, is analyzed by using 2-dimensional numerical simulation in this paper. The results show that the lower leakage current and the improved robustness of the field limiting ring termination can be obtained by introducing a p type corrugated resistance region. During the reverse recovery, the corrugated resistance region can reduce the current density at the anode edge, and produce two lower electric fields which simultaneously undertake the peak electric field caused by the holes drifting to the anode side. The surface electric field at the anode edge is transferred into the body near the pn- junction curvature. As a result, the robustness of the field limiting ring termination can be improved compared with the conventional field limiting ring termination. Moreover, this design does not increase the extra fabrication process.