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Abstract: In absolute ethanol, ultrafine SiO2 particles were prepared by hydrolyzing tetraethylorthosilicate using ammonia as catalyst and calcined at 500℃ for 1h. CeO2@SiO2 composite nanoparticle was obtained by immersing SiO2 in sols with different cerium ion concentrations, which were prepared using cerium nitrate, diacetone, normal propyl alcohol as raw materials. The phase composition, morphology, particle size and agglomerate of the samples were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and infrared spectroscopy (FT-IR). The slurry collocated by as- prepared CeO2@SiO2 composite nanoparticles was used to polish GaAs wafer (100). The polishing behavior of CeO2@SiO2 composite abrasive was characterized by Atomic Force Microscope (AFM). The results indicated that monodisperse, spherical CeO2-coated SiO2 particles were prepared successfully. The particle size was 400 ~450 nm and SiO2 particle was uniformly coated by CeO2. The amount of coated CeO2 increased gradually with the increase of cerium ion concentration in the sol. After chemical-mechanical polishing by CeO2@SiO2 composite abrasive, ultra-smooth surface of GaAs (100) with a surface roughness (Ra) of 0. 819nm within 1μm × 1μm area was obtained.
Key words: CeO2@SiO2 composite abrasive, impregnating, coating, gallium arsenide, polishing
Author: Zhao Xiaobing, Associate Professor, Department of material and engineering, Jiangsu polytechnic university Changzhou, Jiangsu 213164, China
E-mail: zhaoxiaobing00@163.com
Tribology, Vol. 29, Issue 5, 2009, 412-417. |
