基于分子动力学单晶锗的纳米压痕特性分析

Nanoindentation Characteristics Analysis of Single Crystal Germanium Based on Molecular Dynamics

单晶锗属于硬脆性光学半导体材料,加工时易产生裂纹和凹坑等缺陷,严重影响其表面质量.为了达到纳米级的表面质量,本文采用分子动力学模拟从不同晶面和晶向对单晶锗进行纳米压痕分析,在纳米尺度下对其进行压痕加载和卸载,分析该过程中载荷的变化情况,得到弹性模量的变化差异.结果表明,加载前后弹性模量差异小的单晶锗(111)晶面可以作为实际生产中的加工面,从而获得高质量的加工表面.

Single crystal germanium, a hard and brittle optical semiconductor material, is vulnerable to cracks and potholes which destroy the surface quality seriously.In order to obtain nano-scale surface quality, nanoindentation of single crystal germanium on different crystal planes and crystal orientations was analyzed with molecular dynamics simulation in this paper.Variation of load was obtained in the process of indentation loading and unloading on the single crystal germanium in nano-scale, which can render the difference of elastic modulus.The （111） crystal plane of single crystal germanium shows tiny difference of elastic modulus before and after loading, which can be used as the surface to be machined in production for higher-quality surface.