电场偏置对MOS器件电离辐射效应的影响

Dependence of Electric Field Bias on Ionizing Radiation Effect of MOS Devices

研究了外加电场对MOS器件电离辐射效应的影响。采用10 keV X射线对MOS器件在正/反电场偏置条件下进行总剂量辐射,分析了MOS器件辐射前后阈值电压的漂移量。实验结果表明,正偏情况下MOS器件的阈值电压漂移量远大于反偏情况下MOS器件的阈值电压漂移量。基于一维连续性方程,在考虑电子-空穴对的复合/逃逸率、电子及空穴的捕获横截面与外加电场关系的基础上,模拟了辐射诱生栅氧化层内陷阱电荷与辐射总剂量之间的关系,分析了陷阱电荷对MOS器件阈值电压的影响,仿真结果与实验数据吻合良好。

Dependence of electric field bias on ionizing radiation effect of MOS devices was studied.Total dose radiation was done on MOS devices at both forward and negative electric field biases using 10 keV X-ray.Threshold voltage shift was analyzed before and after radiation.Experiment result showed that threshold voltage shift at forward bias was much bigger than that at negative bias.Based on 1-D continuity equation and with consideration of the influence of external electric field on trap cross section and escape probability of electrons and holes,the relationship between trapped charge in rediation induced gate oxide and radiation total dose was simulated.Simulation result was in good agreement with experimental data.