单粒子瞬变中的双极放大效应研究

采用三维数值模拟的方法对比研究了单个NMOS晶体管和反相器链中的单粒子瞬变（single event transient,SET）电流脉冲，发现深亚微米工艺下双极放大电流在单管的SET电流脉冲中占主要成分，而在反相器链的SET模拟中不明显，分析二者的区别解释了源/体结偏压的形成过程和放大机理，并证明了双极放大效应受源/体结偏压影响的结论.在此基础上分析了NMOS管中源极的正向电流及其机理，发现台阶区的源极正向电流主要是由扩散作用形成的.关键词：单粒子瞬变双极放大混合模拟台阶区电流

Research of bipolar amplification effect in single event transient

Using 3-D mixed-mode simulation, bipolar amplification effect in an inverter chain of single event transient(SET) is studied, and compared with that in single NMOS. It is found that bipolar amplification component takes a large proportion in SET current pulse, but not in an inverter chain. The difference of source/substrate biases between them and the mechanism of amplification are explained, which validates the conclusion that bipolar amplification depends on the bias of source/substrate. The positive current component from source to drain and the mechanism of SET pulse are also studied, and results show that the source current change is positive in the plateau region because of the presence of carrier diffusion.