重离子和脉冲激光诱发单粒子效应的等效性研究

By research on the equivalent properties analysis of Single Event Effects (SEE) induced by heavy ion and pulsed laser beam, The differences of track-structure in silicon induced by heavy ion and pulsed laser beam will be compared theoretically. The equivalent characteristic parameters of track-structure will be presented. In the experimental study, the quantity of collection charge from ionizing track of heavy ion and pulsed laser beam is to measure respectively, and the experimental data will be analyzed and compared according to the equivalent parameters of SEE. Basis on comparing analysis of the experimental results, the physical mechanisms of equivalent properties of SEE induced by heavy ion and pulsed laser beam will be presented. The correlation between the collection charge quantity from ionizing track of heavy ion and the one of pulsed laser beam will be deduced. The studies are of benefit to improve the accuracy of SEE experiment data obtaining by utilizing pulsed laser beam. By comparing analysis of distribution properties and the transport and collection procedures of the charge in semiconductor induced by heavy ion and pulsed laser,the concept and ways to character physical procedure of SEE induced by pulsed laser will be explored.The goal of the studies is gain an insight into the concept and ways to character the physical procedure of SEE induced by pulsed laser beam, and also to supply the reference basis for radiation hardening design , modeling and predicting of SEE on semiconductor and integrated circuits.

通过对重离子和脉冲激光诱发单粒子效应基本过程的等效性分析研究，从理论上分析比较重离子和脉冲激光在半导体硅材料中产生电离径迹结构的异同，给出两种不同电离过程形成的电离径迹结构物理特性的描述参数；实验上测量重离子和脉冲激光在半导体材料中电离产生电荷的传输和收集特性，然后将试验结果进行比对分析，明确两种模拟源诱发单粒子效应等效性分析的基本物理过程；建立脉冲激光能量与不同能量重离子诱导电荷收集量之间的等效关系，提高地面模拟试验评估结果的科学性和准确性。通过比较研究高能重离子和脉冲激光在半导体器件中产生的诱导电荷的分布、传输及收集机理，提出重离子和脉冲激光诱发单粒子效应的等效性分析方法，探索描述脉冲激光诱发单粒子效应物理过程的新方法和新概念，为半导体器件和集成电路单粒子效应建模分析及抗辐射加固设计提供基本参考依据。

本项目围绕脉冲激光和重离子诱发单粒子效应的等效性问题，完成了四个方面的研究内容，即半导体材料空间重离子和脉冲激光电离径迹结构理论研究，重离子和脉冲激光穿越PN结时产生电荷的收集机理分析，重离子和脉冲激光电离径迹结构测量试验研究及重离子电离过程和脉冲激光电离过程诱发单粒子效应等效性分析。通过脉冲激光束与重离子电离径迹结构计算结果的比较分析发现，重离子在Si中电离产生的电子-空穴对浓度（EHPs）随径迹半径变大而降低；在低能情况下，重离子的电离径迹半径小于激光电离径迹半径，重离子径迹中心处EHPs浓度比激光的至少高三个数量级，但两者的电离径迹分布结构形状相似。在重离子和脉冲激光穿越PN结时产生电荷的收集机理分析研究中，通过二极管结构建模，采用TCAD软件对重离子穿越PN结时产生电荷的收集机理分析结果表明，反偏电压越高，PN结收集的瞬态电流越大；在给定反偏压下，入射离子能量越高，PN结的收集电荷反而减小；脉冲激光仿真计算结果表明，脉冲激光束入射PN结产生的EHPs约在0.1ns的时间内被结区电场通过漂移或聚焦所收集，而达到峰值电流；电流收集曲线也呈现出电荷扩散造成的拖尾特征。重离子和脉冲激光电离径迹结构测量试验结果表明，脉冲激光在PN结中诱发产生的沉积电荷量大小与脉冲激光能量成非线性关系，依据本项目试验数据和其它相关实验数据，通过对电荷收集总量与重离子LET值、脉冲激光能量之非线性关系分析，明确了脉冲激光与重离子诱发单粒子效应过程的“漏斗效应”之不同。建立了脉冲激光能量与重离子LET值在电离电荷收集量之间的关系，提高了地面模拟试验评估结果的科学性和准确性，探索了描述脉冲激光诱发单粒子效应物理过程的新方法和新概念；基于取得的重要结果和关键数据，针对国产辐射加固器件开展了验证实验。