关键词: 功率VDMOS, SEB, 缓冲层, 抗辐射加固

Abstract: The addition of a buffer layer between the epitaxial layer and the substrate can improve the device’s secondary breakdown voltage, thus, improving the single event burnout (SEB) threshold voltage of the device.The secondary breakdown characteristics and the electric field distribution of radiation-resistant VDMOS devices with a single constant doping buffer layer and a linearly graded doping buffer layer are simulated.At the buffer layer/N⁺ substrate interface for the doping mutation, the electric field is 1.7×10⁵ V/cm for the linearly graded doping buffer layer and 2.4×10⁵ V/cm for the single constant doping buffer layer.The results of ¹⁸¹Ta particle radiation test showed that the SEB threshold voltage of the linearly graded doping buffer layer is better than that of the single constant doping buffer layer, and the SEB threshold voltage of the linearly graded doping buffer layer sample is greater than 250 V, and the SEB threshold voltage of the single constant doping buffer layer sample is 150~200 V.

Key words: power VDMOS, single event burnout, buffer layer, radiation hardened reinforcement