Be原子在Be基底上的沉积过程研究

Atomistic study of deposition process of Be thin film on Be substrate

利用分子动力学方法模拟了Be原子在Be基底上的沉积过程.模拟了沉积粒子不同入射动能条件下,沉积薄膜表面形态的差异.在一定能量范围内,增加粒子入射动能可以减小薄膜的表面粗糙度.但是,过高的入射动能,不利于减小薄膜表面粗糙度.通过沉积薄膜中原子配位数以及单个原子势能沿薄膜厚度的分布,分析沉积原子入射动能对于薄膜及表面结构的影响.沉积动能较大时,薄膜的密度较大;单个原子势能沿薄膜厚度分布较为连续;同时薄膜中原子应力沿薄膜厚度分布较为连续.最后,分析了沉积粒子能量转化的过程、粒子初始动能对基底表面附近粒子局部动能增加的影响.

The deposition process for Be atoms on Be substrate is studied using molecular dynamic simulations. The morphologies of the deposited films are distinctly different under different incident energies. In a specified range, the surface roughness of the film decreases with the increase of the incident energy. However, the over-high incident energy is unfavourable for reducing the surface roughness of the film. The distributions of the coordination numbers and potential energy of the single atom are used to analyze the film structure under different incident energies. With the bigger incident energy the density of the film is bigger and the distribution of the potential energy of the single atom is more continuous. At the same time, the distribution of the atomic stress is more continuous. Finally, the energy conversion process of the single atom is given, and the influence of the initial incident energy on the locally accelerated energy near the substrate is analyzed.