电子信息工程专业导论论文

本科毕业设计（论文）

题目正弦波纹形貌金属表面

二次电子发射特性的数值仿真研究

Sine corrugated metal surface secondary electron

emission characteristic of the numerical simulation research

作者姓名李玉

专业名称电子信息工程

学科门类理学

指导老师柳钰

提交论文日期二〇一四年五月

成绩等级评定

摘要

入射电子诱发的金属二次电子发射现象在现代电子仪器、装置与器件中起着重要的作用，而电子与粗糙金属表面的复杂多次相互作用会影响二次电子发射特性，对此，目前仍缺乏准确可靠的数值仿真分析，对粗糙金属表面的二次电子发射过程及相关特性也缺乏足够的了解。

本文建立了综合考虑电子在金属中的散射、二次电子的激发、电子向表面的迁移直至从表面逃逸、出射电子与粗糙表面多次相互作用等过程的数值计算模型，在此模型的基础上，基于正弦波纹的粗糙表面，对金属材料的二次电子发射产额、能谱和角度分布随表面形貌参数变化的规律进行了数值模拟分析。计算表明：正弦表面的二次电子发射产额随半宽振幅比增大是先增大后减小，顶部入射时接近理想平面的产额。同时发现，复杂形貌表面对二次电子产额的影响可能产生抑制或者增大两种截然相反的效果，则在表面加工过程中需要控制形貌结构参数来达到对二次电子产额的增强或抑制要求，为其寻找增强或抑制二次电子发射方案提供了指导性判据。

本文的研究工作及其结果对于丰富复杂表面条件下的金属二次电子发射理论，提高各种涉及金属二次电子发射的表面成像与分析仪器、加速器、微波器件的性能，具有科学意义和应用价值。

关键词：二次电子发射；金属；正弦波纹形貌；数值仿真

Abstract

The phenomenon of secondary electron emission (SEE) from metal under electron bombardment has important value in the application of many modern electronic devices. SEE characteristics are affected by the interaction between secondary electrons(SEs)and surfaces with complex topography. However, there still lacks an accurate and reliable numerical simulation analysis for the SEE from the complex surfaces, as well as the knowledge of the related microscopic mechanism.

This paper established a comprehensive consideration in metal electron scattering, secondary electron excitation, electronic migration to the surface to escape from the surface, the interaction between electron and rough surface many times such as numerical calculation model of process, on the basis of this model, based on sine corrugated rough surface, the secondary electron emission yield of metal material, energy and Angle distribution with the rule of surface topography parameters are simulated analysis. Calculation showed that the sinusoidal surface of secondary electron emission yield increases with half wide amplitude ratio is increased after the first decreases, and the top yield close to ideal plane from the entrance. Also found that the complex surface topography influence on secondary electric quantum yield increases that may inhibit or two opposite effects, the need to control in the process of machining surface morphology structure parameters to achieve the secondary electric quantum yield to enhance or inhibit requirements, enhance or inhibit the secondary electron emission for its scheme provides a guiding criterion.

Finally, this work and obtained results are helpful for the further SEE study of complicated metal surfaces and corresponding microscopic mechanisms, and therefore can be referred for practical efforts of SEY suppression .

Key words: Secondary electron emission；Metal；Rough surface morphology；Numerical simulation