纳米磨料对GaAs晶片的抛光研究

通过均相沉淀法制备了纳米CeO2和Al2O3粉体,研究了在相同抛光条件下纳米CeO2、SiO2和Al2O3磨料对GaAs晶片的抛光效果,并用原子力显微镜观察抛光表面的微观形貌并测量表面粗糙度。结果表明,使用纳米CeO2磨料抛光后的表面具有最低的表面粗糙度,在1μm×1μm范围内表面粗糙度Ra值为0.740nm,而且表面的微观起伏更趋于平缓。文中还探讨了GaAs晶片化学机械抛光材料去除机理,考虑了纳米磨料在抛光条件下所发生的自身变形,并分析了纳米磨料硬度对抛光表面粗糙度的影响,初步解释了在相同的抛光条件下不同硬度的纳米磨料为什么具有不同的抛光表面粗糙度。

Study on the Polishing of GaAs Wafer Using Nano-sized Abrasives

Nano-powder of CeO_2 and Al_2O_3 were prepared via homogenous precipitation, and the different polishing behavior of nano-CeO_2, nano-SiO_2, and nano-Al_2O_3 abrasives under the same polishing condition were studied by atomic force microscope (AFM). The surface roughness of the GaAs wafer polished by nano-CeO_2 was lower than that polished by the nano-Al_2O_3 and nano-SiO_2, and the surface undulation was smaller. The influence of the deformation of the abrasive particle on polishing mechanism was considered, and the material removal mechanism in chemical-mechanical polishing of GaAs wafer was also discussed. It was found that the deformation amount was related to the hardness of the abrasives. That was the reason why the nano-sized abrasives with different hardness had different polishing behavior.