Modeling of NMOS transistors for simulation of atmospheric neutron environment and SEEs on SRAM-based FPGAs

摘要

A new simulation design against Single Event Effects (SEEs) is proposed in this paper, for the analysis and the implementation of circuits on Static Random Access Memory (SRAM) based Field-Programmable Gate Arrays (FPGAs). Firstly, SEEs mechanism and process was summarized. Then Monte Carlo method was used to calculate the neutron energy spectrum distribution at different height of the near space (20 ~ 100km). Secondly, NMOS transistors was confirmed the sensitive structure cell through mechanism analysis of SEEs. And TCAD software is used to set up the three-dimensional model of NMOS. The effectiveness of the proposed simulation design has been evaluated and compared by performing three different LET on six-transistor cell. Results have been validated against radiation-beam testing using atmospheric neutron and show that the effect of LET is mainly concentrated on the peak of the current pulse, not the maintenance time.