Fig. 1.
Structure of 300 mm copper pattern wafer. (a) Cross sectional view. (b) Step height test position.
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Shengli Wang, Kangda Yin, Xiang Li, Hongwei Yue, Yunling Liu. Planarization mechanism of alkaline copper CMP slurry based on chemical mechanical kinetics[J]. Journal of Semiconductors, 2013, 34(8): 086003. doi: 10.1088/1674-4926/34/8/086003
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S L Wang, K D Yin, X Li, H W Yue, Y L Liu. Planarization mechanism of alkaline copper CMP slurry based on chemical mechanical kinetics[J]. J. Semicond., 2013, 34(8): 086003. doi: 10.1088/1674-4926/34/8/086003.
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Planarization mechanism of alkaline copper CMP slurry based on chemical mechanical kinetics
DOI: 10.1088/1674-4926/34/8/086003
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Abstract
The planarization mechanism of alkaline copper slurry is studied in the chemical mechanical polishing (CMP) process from the perspective of chemical mechanical kinetics. Different from the international dominant acidic copper slurry, the copper slurry used in this research adopted the way of alkaline technology based on complexation. According to the passivation property of copper in alkaline conditions, the protection of copper film at the concave position on a copper pattern wafer surface can be achieved without the corrosion inhibitors such as benzotriazole (BTA), by which the problems caused by BTA can be avoided. Through the experiments and theories research, the chemical mechanical kinetics theory of copper removal in alkaline CMP conditions was proposed. Based on the chemical mechanical kinetics theory, the planarization mechanism of alkaline copper slurry was established. In alkaline CMP conditions, the complexation reaction between chelating agent and copper ions needs to break through the reaction barrier. The kinetic energy at the concave position should be lower than the complexation reaction barrier, which is the key to achieve planarization. -
References
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