模拟扫描电镜像衬度的体构件Monte Carlo方法

利用Mollte Carlo计算方法可以模拟电子束与样品的相互作用过程，从而了解扫描电子显微学中信号的产生机制，本工作中，我们采用体构件法来产生复杂试样的几何构型，利用光线追踪算法求得散射事件间的步长抽样修正。电子散射的物理模型则采用Mott散射截面描述电子与原子间的弹性相互作用，以及用介电函数理论描述电子与固体的非弹性相互作用，同时还考虑到了二次电子的级联产生过程．以此，我们模拟计算出了若干复杂几何体的二次电子像和背散射电子像。

Combined Monte Carlo method with constructive solid geometry modeling for the simulation of image contrast in scanning electron microscopy

Using Monte Carlo method we can simulate the interaction process of electron beam with specimen and, therefore, to understand the mechanism of signal production in scanning electron microscopy. In this work, we have employed constructive solid geometry modeling to construct the geometrical configuration of complex specimen, and, the ray tracing arithmetic to obtain the correction to the sampling of the flight step length between scattering events. The physical model of electron scattering is based on the use of Mott cross section to describe the elastic interaction of electrons with atoms, and, of a dielectric function approach to electron inelastic interaction with solids; furthermore, cascade secondary electron production process is included. This has enabled us to obtain the simulated secondary electron images and backscattered electron images for a number of complex specimen made of geometrical objects.