磨料的粒径分布严重影响铜膜抛光效果，单一粒径磨料在抛光过程中，部分较大或较小磨料的作用难以准确评估。针对这一问题，采用不同且粒径相近（40、60和80 nm）的磨料混合来表征反映粒径分散性对铜膜抛光的影响，研究单一磨料、2种和3种粒径磨料混合的抛光液对硅通孔铜膜抛光的影响。结果表明：在相同质量分数条件下，不同粒径磨料混合能提高铜膜抛光速率和改善表面质量；2种粒径磨料混合时，粒径差距越大，则抛光速率越快；3种粒径磨料混合时其抛光速率和抛光表面质量优于单一粒径和2种粒径混合，当40、60和80 nm 3种粒径磨料的比例为1∶3∶2时，抛光效果最好。建立铜片与抛光垫之间磨料分布的物理模型，揭示混合磨料提高铜膜去除速率的机制，计算出磨料与铜片的接触面积。
The particle size distribution of abrasives has a serious impact on the polishing effect of copper film.In the polishing process of abrasives with a single particle size,it is difficult to accurately evaluate the effect of some large or small abrasives.To solve this problem,different abrasive mixtures with similar particle sizes (40 nm,60 nm and 80 nm) were used to characterize the effect of particle size dispersion on copper film polishing.The effect of polishing liquid mixed with single abrasive,2 and 3 abrasive sizes on the polishing of silicon through hole copper film was studied.The results show that the polishing rate and surface quality of copper film can be improved by mixing abrasive with different particle sizes at the same mass fraction.When two kinds of abrasives are mixed,the larger the particle size difference,the faster the polishing speed.The polishing rate and polishing surface quality of abrasives mixed with three particle sizes are better than that of single particle size and two particle sizes.When the ratio of 40 nm,60 nm and 80 nm abrasives is 1∶3∶2,the polishing effect is the best.The physical model of abrasive distribution between copper sheet and polishing pad was established,the mechanism of increasing the removal rate of copper film with mixed abrasive was revealed,and the contact area between abrasive and copper sheet was calculated.
ZHENG Qingping, WANG Ru, WU Tongxi. Effect of Abrasive Mixing on Polishing Effect of Through Silicon Via Copper Film[J]. Lubrication Engineering,2022,47(12):117-124.