基于PDSOI单粒子翻转物理机制的SPICE模型研究

A Study of Physics-basis SEU SPICE Model

通过研究半导体器件单粒子翻转的物理机制,利用Synopsys TCAD工具对基于中国科学院微电子所开发的0.35μm部分耗尽SOI器件进行单粒子翻转的模拟,讨论了器件模拟物理模型的选择,验证了理论分析的正确性,并对重离子撞击引起的瞬态电流过程进行分析.分析表明单粒子翻转存在两个放电阶段,第一阶段过量电子漂移扩散电流组成激增电流部分;第二阶段部分耗尽SOI器件寄生三极管放电机制以及过量空穴放电机制引起的缓慢电流放电"尾部".结合激增电流的物理意义,提出合理的数学模型,推导出描述此电流的一维解析解;对于缓慢衰减的"尾部"电流,提出子电路模型,并基于SPICE三极管模型进行参数提取,着重讨论了单粒子翻转的敏感参数.最后给出了以反相器为例的SPICE模拟与TCAD模拟在瞬态电流,输出节点电荷收集,LET阈值的对比结果,验证了SPICE模型的合理性和精确性.

According to the physical mechanics of single event upset（SEU）,a two-dimensional simulation based on 0.35 μm PDSOI MOSFET explored by the Institute of Microelectronics of Chinese Academy of Sciences,has been done to assist to analysis the transit current induced by ion striking,for the purpose of citifying the electrical behaviors.The analysis result shows that there have two discharging phases during SEU,one is the excess electrons diffusion and drift current forming the prompt current;then the parasitic bipolar of PDSOI and the excess holes forming the long discharging current ＂tail＂.Combining with the fundamental physical mechanism,a mathematic model is proposed,providing with a one-dimensional analytical solution.A simple sub circuit model is necessary to characterize the extra longer delay part.Focusing on discussion of the sensitive parameter of SEU,this paper describes explicitly on the parameter extraction.An inverter is used as an example to compare the result between SPICE and TCAD simulation with the transient current,the collected charge of output node,and the LET threshold,which prove that the SEU SPICE model is reasonable and accurate to predict SEU effect.