Abstract The effect of complexing agents on Co oxidation/dissolution in alkaline solution was investigated for Co chemical-mechanical polishing (CMP) and post-CMP cleaning processes. The oxidation and dissolution properties of Co in a solution are greatly affected by complexing agents, which could influence the performance of Co CMP and post-CMP cleaning processes. Herein, three complexing agents, glycine, ethylenediaminetetraacetic acid (EDTA), and citric acid were studied. It was revealed that the complexing agents determined Co dissolution rate depending on the presence or absence of H2O2. Glycine showed a higher Co dissolution rate than EDTA and citric acid in the absence of H2O2, while EDTA showed the highest dissolution rate in the presence of H2O2. Negligible dissolution was observed with citric acid, regardless of the presence of H2O2. Electrochemical impedance and UV–Vis spectroscopies found that the difference in Co dissolution rates was related to Co oxidation rate and complexation capability of each complexing agent. Glycine showed a higher Co oxidation rate than EDTA, while EDTA had a much higher complexation capability than glycine. Citric acid exhibited the lowest Co oxidation rate and complexation capability, resulting in the slowest Co dissolution rate.

中文翻译：

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化学机械抛光清洗工艺中络合剂对Co氧化/溶解影响的研究

摘要 在 Co 化学机械抛光 (CMP) 和 CMP 后清洗工艺中，研究了络合剂对 Co 在碱性溶液中氧化/溶解的影响。Co 在溶液中的氧化和溶解特性受络合剂的影响很大，络合剂会影响 Co CMP 和 CMP 后清洗工艺的性能。在此，研究了甘氨酸、乙二胺四乙酸 (EDTA) 和柠檬酸三种络合剂。结果表明，络合剂根据 H2O2 的存在与否决定了 Co 的溶解速率。在不存在 H2O2 的情况下，甘氨酸显示出比 EDTA 和柠檬酸更高的 Co 溶出率，而 EDTA 在 H2O2 存在下显示出最高的溶出率。无论是否存在 H2O2，用柠檬酸观察到的溶解都可以忽略不计。电化学阻抗和紫外-可见光谱发现 Co 溶解速率的差异与 Co 氧化速率和每种络合剂的络合能力有关。甘氨酸显示出比 EDTA 更高的 Co 氧化速率，而 EDTA 具有比甘氨酸高得多的络合能力。柠檬酸表现出最低的 Co 氧化速率和络合能力，导致最慢的 Co 溶解速率。