Tribology Research Institute, National Traction Power Laboratory, Southwest Jiaotong University, Chengdu 610031, Sichuan Province, P. R. China.
School of Mechatronics Engineering, University of Electronic Science and Technology of China, Chengdu 611731, Sichuan Province, P. R. China.
Sci Rep. 2017 Jan 13;7:40750. doi: 10.1038/srep40750.
The effect of crystal plane orientation on tribochemical removal of monocrystalline silicon was investigated using an atomic force microscope. Experimental results indicated that the tribochemical removal of silicon by SiO microsphere presented strong crystallography-induced anisotropy. Further analysis suggested that such anisotropic tribochemical removal of silicon was not dependent on the crystallography-dependent surface mechanical properties (i.e., hardness and elastic modulus), but was mainly attributed to various atomic planar density and interplanar spacing in different crystal planes. Phenomenological results speculated that higher density of silicon atom could promote the formation of Si-O-Si bonds between the SiO microsphere and silicon substrate, resulting in more severe tribochemical material removal. Larger interplanar spacing with smaller energy barrier facilitated the rupture of the Si-Si network with the help of mechanical shearing stress, which caused more serious wear of the silicon surface. The results may help understand the material removal mechanism of silicon and provide useful knowledge for chemical mechanical polishing.
使用原子力显微镜研究了晶体面取向对单晶硅摩擦化学去除的影响。实验结果表明，SiO 微球对硅的摩擦化学去除具有强烈的晶体各向异性。进一步的分析表明，硅的这种各向异性摩擦化学去除并不依赖于晶体依赖性的表面机械性能（即硬度和弹性模量），而是主要归因于不同晶体平面中不同原子面密度和层间距。现象学结果推测，硅原子密度较高可以促进 SiO 微球和硅衬底之间 Si-O-Si 键的形成，从而导致更严重的摩擦化学材料去除。较大的层间距和较小的能垒有助于在机械剪切应力的作用下破坏 Si-Si 网络，从而导致硅表面更严重的磨损。研究结果有助于理解硅的材料去除机制，并为化学机械抛光提供有用的知识。
