利用自制旋转圆盘空蚀试验装置,以流动自来水为介质,对磨片、化抛片、抛光片和刻蚀片等4种硅片进行连续8 h试验以及对磨片进行连续14 h跟踪观察试验,研究硅材料的微观破坏过程,并利用扫描电子显微镜、触针式表面形貌仪和原子力显微镜对其表面微观形貌进行分析.结果表明:经连续8 h空蚀试验后,磨片原始表面的片状层基本消失,表面破坏程度最严重,化抛片次之,其表面尖锐的边缘发生了钝化,抛光片和刻蚀片的表面变化不大;化抛片的表面粗糙度Ra值由227.79 nm降至173.31 nm,抛光片的Ra值由0.483 nm增加至3.455 nm,磨片在14 h试验后其Ra值由0.3304 μm降至0.1965 μm;一定尺度的表面微观形貌对硅材料产生显著影响.
Micro-occur of Si wafer under rotating disk test has been studied. Four kinds of Si wafers, including ascut wafer, chemically eroded wafer, polished wafer and etched wafer, were tested in tap water for 8 hours by the self-made rotating disk test rig. Scanning Electron Microscope (SEM), Surface Profilometer and Atomic Force Microscope (AFM) were used to analyze the surface properties of the Si wafer. SEM results indicate that after 8 h test among the four wafers, as-cut wafer damaged most severely because its lamina layers on the original surface vanished, and then as-cut wafer for its keen edge were smoothed, the polished and etched ones damaged most slightly because changes can hardly be found after test. AFM analysis showed that after 8 h test the surface roughness of the chemically eroded wafer decreases from 227.79 nm Ra to 173.31 nm Ra while that of the polished one increases from 0.483 nm to 3. 455 nm. Micro-occur of the as-cut wafer was observed by SEM continuously during 14 h test and the surface roughness decreased from 0.3304 μm Rn to 0. 1965 μm R. The results showed that the degree of material damage of Si was determined by the dimension of its micro topography.