氧化铝抛光液对铝合金化学机械抛光性能的研究

化学机械抛光(CMP)已成为金属合金最具潜力的平坦化技术. 为了优化铝合金CMP工艺，研究了磨料粒度、分散剂浓度以及pH调节剂对铝合金CMP性能的影响. 结果表明:随着磨料粒度的增加，材料去除率(MRR)和平均表面粗糙度(R_a)均增加，而表面光泽度(G_s)降低. 分散剂(聚乙二醇，PEG-600)的质量分数达到0.5%时，可以获得最优的表面质量和最佳的光泽度. 浆料中添加适量的柠檬酸作为pH调节剂可同时获得较优的表面质量和较高的抛光效率，柠檬酸对铝合金CMP性能的影响是腐蚀作用和螯合作用的综合效应. 此外，简要讨论了氧化铝抛光液对铝合金的静态刻蚀机理和CMP机理. 氧化铝抛光液的最优配方为Al₂O₃ 3.3 μm、H₂O₂ 4%、PEG-600 0.5%和H₃Cit 1.5%. 

Chemical Mechanical Polishing of Aluminum Alloys using Alumina-Based Slurry

Chemical mechanical polishing has become potential global planarization technology for metal alloy. In this paper, we reported the CMP performances of aluminum alloy using alumina-based slurry. The influence of abrasive size, dispersant concentration (weight fraction) and pH-controlling agents on CMP performances were investigated, respectively. It is found that, with the particle size increased, the material removal rate and average surface roughness increased, while the glossiness decreased. When the weight fraction of PEG-600 reached 0.5% (weight fraction), the minimum R_a and the best glossiness can be achieved. Among kinds of the pH-controlling agents, citric acid proved to be efficient for lowest statics etch amount, highest MRR and best glossiness. In addition, the static etch and CMP mechanisms of alumina-based slurry were briefly discussed. The mechanisms revealed that citric acid on Al alloy CMP performance: responsed to combined effects of corrosion and chelation. The optimized alumina-based slurry ingredient was Al₂O₃, 3.3 μm; H₂O₂, 4%; PEG-600, 0.5%; H₃Cit, 1.5%. This is different from the traditional polishing, in which hazardous chemicals HNO₃ and H₂SO₄ were used for Al alloys.