【摘要】 目的制备分散稳定性良好的α-Al₂O₃纳米粒子抛光浆料,提高对蓝宝石的化学机械抛光性能。方法将α-Al₂O₃分散在硅溶胶、氧化铈溶胶、水等不同分散介质中,于不同p H值、不同硅溶胶浓度及硅溶胶粒径等条件下制备出α-Al₂O₃纳米粒子的抛光浆料,考察抛光浆料的稳定性及抛光浆料对蓝宝石化学机械抛光性能的影响。采用Zeta电位仪测量抛光浆料中α-Al₂O₃的电势,进而对其分散稳定性进行分析。采用原子力显微镜（AFM）和分析天平分别对蓝宝石表面粗糙度（Ra）和材料去除速率（MRR）进行评价。结果分散介质为硅溶胶时,抛光浆料的稳定性及对蓝宝石的抛光性能较好。当抛光浆料p H值为10时,其分散稳定性较好,且化学腐蚀与机械研磨达到动态平衡,抛光浆料对蓝宝石的抛光性能较好。随着α-Al₂O₃浓度的增大,浆料的抛光性能呈现先增加后降低的趋势,当α-Al₂O₃的质量分数为10.0%时,抛光浆料对蓝宝石的抛光性能较好。当硅溶胶的质量分数为0.02%时,抛光浆料的分散稳定性及对蓝宝石的抛光性能较好。随着硅溶胶粒径的增加,抛光浆料的稳定性及对蓝宝石的抛光性能逐渐变差,所以选择最小粒径5 nm的硅溶胶作分散介质。即在10.0%的α-Al₂O₃、0.02%粒径为5 nm的硅溶胶、p H值为10等条件下的抛光浆料稳定性较好,该浆料对蓝宝石抛光的材料去除速率为15.16 nm/min,抛光后的表面粗糙度为0.272 nm,满足蓝宝石后续外延工艺要求。结论适宜浓度的硅溶胶能明显改善α-Al₂O₃抛光浆料的分散稳定性,分散效果明显优于水或氧化铈溶胶作分散介质,且对蓝宝石的抛光性能得到显著提高。更多还原

【Abstract】 The paper aims to prepare Al₂O₃ nanoparticles polishing slurry of good dispersion stability to improve the chemical and mechanical polishing performance of sapphire.The polishing slurry ofα-Al₂O₃ nanoparticles was prepared by dispersingα-Al₂O₃ in different dispersion media such as silica sol,cerium oxide sol and water of different pH values,silica sol concentrations and silica sol particle size,to investigate the stability of polishing slurry and the effect of polishing slurry on the chemical and mechanical polishing performance of sapphire.The potential ofα-Al₂O₃ was measured with a Zeta potentiometer to analyze the dispersion stability of slurry.The surface roughness（Ra）and material removal rate（MRR）of sapphire were evaluated by atomic force microscopy（AFM）and dynamic balance,respectively.When silica sol was used as the dispersion medium,the stability of the polishing slurry and the polishing performance of sapphire were good.When the pH value of the polishing slurry was 10,it had good dispersion stability,and the chemical corrosion and mechanical grinding reached a dynamic balance.The polishing slurry had good polishing performance for sapphire.As the concentration ofα-Al₂O₃ increased,the polishing performance of the polishing slurry increased first and then decreased.When the mass fraction ofα-Al₂O₃ was 10.0%,the polishing slurry had good polishing performance to sapphire;when the mass fraction of silica sol was 0.02%,the dispersion stability of the polishing slurry and the polishing performance to sapphire were good.As the particle size of the silica sol increased,the stability of the polishing slurry and the polishing performance to sapphire gradually deteriorated,so a silica sol with the minimum particle diameter of 5 nm was selected as a dispersion medium.In other words,the polishing slurry under the conditions of 10.0%α-Al₂O₃ and 0.02%silica sol with a particle diameter of 5 nm,and a p H value of 10,etc.,had good stability.The slurry had a material removal rate of 15.16 nm/min for sapphire polishing and a surface roughness of 0.272 nm,satisfying the requirements on subsequent epitaxial process of sapphire.The silica sol of suitable concentration can significantly improve the dispersion stability ofα-Al₂O₃ polishing slurry.Its dispersion effect is obviously superior to that of water or cerium oxide sol as a dispersion medium.The polishing performance of sapphire is significantly improved.更多还原