波型结构样品二次电子发射的Monte Carlo模拟（英文）

Monte carlo simulation of secondary electron emission from wave-type structure

用于研究电子与固体相互作用的Monte Carlo(MC)模拟技术已成功应用于获得测长扫描电子显微镜(CD-SEM)中的线扫描轮廓曲线.以前的研究主要关注具有尖锐边缘的简单几何形状的样品,为此将相应的模拟扩展到具有平滑弯曲形貌的波形结构样品.MC模拟模型用Mott截面描述电子的弹性散射以及基于完全Penn算法的介电函数理论描述电子的非弹性散射.综合考虑了不同实验因素,如电子束能量,几何参数和材料性质对波型结构样品CD-SEM线扫描曲线的影响;计算表明,随着样品结构高度的降低,二次电子的两个侧边峰可以合并成一个中心单峰,该特征为平滑线状结构样品的关键尺寸表征带来了新的挑战.

Monte Carlo (MC) simulation techniques for the study of electron interaction with solids have been successfully applied to obtain the line-scan profiles in critical dimension scanning electron microscopy (CD-SEM). However,previous studies have been mostly concerned about the sample of simple geometries having sharp edges. The simulation was extended to the study of wave-type structures with smooth curved shapes. The MC model is based on using the Mott cross-section for electron elastic scattering and the full Penn algorithm in a dielectric function approach to electron inelastic scattering. The CD-SEM line-scan profiles of wave-type structures have been calculated by taking into account such experimental factors as primary beam energy,geometry parameters and material property. It is shown that by decreasing the height of the structure,the double side peaks can shrink to merge into a single peak. This characteristic will pose a challenge to the CD characterization for the smoothed line structure.