Improvement of Cosmic Ray Robustness in IGBT with Deep-N layer

Single Event Burnout (SEB) is one of the issues causing the blocking instability of high voltage semiconductor devices. In this paper, we suggest introducing Deep N-buffer layer (DN) into IGBT for improvement of the robustness. By TCAD simulation, the destruction mechanism and the effect of the backside structure on SEB robustness were clarified. The result indicated that DN suppressed the temperature rising around P-collector and PNP bipolar action at the backside during the period of the event. The proposed IGBT with DN layer was fabricated and the SEB failure rate was evaluated. The experimental results showed that the proposed structure improved the robustness.