纳米CeO_2颗粒的制备及其对硅晶片(100)和(111)的抛光性能

Preparation Nano-CeO_2 Particles and Its Polishing Performance for Si(100) and Si(111)

以硝酸铈和六亚甲基四胺为原料,在微波辐射条件下,使用乙醇/水反应体系,通过均相沉淀法制备了纳米CeO2颗粒,利用X射线衍射仪(XRD)、透射电子显微镜(TEM)、傅里叶转换红外光谱仪(FT-IR)和比表面积测定仪(BET-N2)等手段对样品的成分、物相结构、形貌、颗粒大小以及团聚情况进行了表征.将所制备的纳米CeO2颗粒作为磨料用于硅晶片(100)和(111)的化学机械抛光,用原子力显微镜(AFM)观察抛光表面的微观形貌,测量表面粗糙度,并对抛光表面划痕进行了分析.结果表明,微波辐射以及乙醇/水反应体系均有利于制备出粒径更小、分散性更好的纳米CeO2颗粒,而且微波辐射能够显著加快反应速度;经纳米CeO2磨料抛光的硅晶片(100)和(111)表面非常平整,在2μm×2μm范围内的粗糙度Ra值分别为0.275 nm和0.110 nm,获得了具有亚纳米量级粗糙度的抛光表面.

Nano-particles of CeO2 were prepared in alcohol/water mixed solvents under microwave radiation using Ce（ NO3 ）3 · 6H2O and HMT as starting materials. The phase and morphology of samples were characterized by X-ray diffraction （ XRD）, transmission electron microscope （TEM） , Fourier transform infrared spectroscopy（FT-IR） and BET-N2. As-prepared nano-CeO2 particles were collocated into polishing slurry for chemical-mechanical polishing of Si（100） and Si（ 111 ）. The polishing behavior of nanosized CeO2 was studied with atomic force microscope （AFM）. The results indicate that microwave radiation and alcohol/water mixed solvents are beneficial to the preparation of nano-CeO2 powder, which is smaller in size and displays better dispersal performance, and microwave radiation can expedite the reaction rate effectively. At last, ultra-smooth surfaces of Si （100） and Si （ 111 ） with roughness （ Ra ） of 0. 275 nm and 0. 110 nm within 2μm×2μm area polished by nano-sized CeO2 were obtained respectively, undulation of which was very small.