基于衬底材料优化的抗辐射功率器件SEB加固技术

Radiation Resistant Power Device SEB Reinforcement Technology Based on Substrate Material Optimization

在外延层和衬底之间增加缓冲层能够提高器件的二次击穿电压,从而提高器件的单粒子烧毁(SEB)阈值电压。仿真对比了抗辐射加固纵向扩散金属氧化物场效应管(VDMOS)的单层缓冲层和掺杂线性梯度变化缓冲层的二次击穿特性和电场分布。在掺杂突变的缓冲层/N^(+)衬底界面位置,线性缓冲层的电场为1.7×10^(5)V/cm,单层缓冲层的电场为2.4×10^(5)V/cm。^(181)Ta粒子辐射试验验证了掺杂线性梯度变化缓冲层的SEB阈值电压优于单层缓冲层,线性缓冲层样品的SEB阈值电压大于250 V,单层缓冲层样品的SEB阈值电压为150~200 V。

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 1.7×10^(5) V/cm for the linearly graded doping buffer layer and 2.4×10^(5) V/cm for the single constant doping buffer layer.The results of ^(181)Ta 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.