阻挡层CMP中铜钴电偶腐蚀的影响因素

发布时间：2018-06-10 09:05

  本文选题：钴 + 铜　； 参考：《微纳电子技术》2017年07期

【摘要】：在Co化学机械抛光(CMP)过程中,Co的化学反应活性强于Cu,Co/Cu界面存在较大的电化学腐蚀电位差。采用动电位扫描电化学技术,表征金属铜钴表面的电化学反应。采用降低Cu/Co接触腐蚀电位差的方法,表征铜钴电偶腐蚀。研究了阻挡层CMP中影响铜钴电偶腐蚀的几个因素:pH值、H_2O_2和FA/O螯合剂;并对其控制机理进行了深入的研究。实验结果表明:pH值对钴的腐蚀电位影响较大,对铜的腐蚀电位影响不大,随着pH值的增加降低了铜和钴的腐蚀电位差;在碱性环境下,H_2O_2可降低Cu和Co的腐蚀电位差(最小可降到3 mV),可有效抑制Cu和Co之间电偶腐蚀现象的产生;在H_2O_2基电解液中添加适量的FA/O螯合剂有助于降低Cu和Co的腐蚀电位差,对抑制Cu和Co电偶腐蚀现象的产生具有重大的作用。
[Abstract]:In the process of chemical mechanical polishing (CMP) of Co, the chemical reaction activity of Co is stronger than that of Cu / Co / Cu. There is a large potential difference in electrochemical corrosion. The electrochemical reaction on the surface of copper and cobalt was characterized by potentiodynamic scanning electrochemical technique. The copper / cobalt galvanic corrosion was characterized by reducing the potential difference of Cu / Co contact corrosion. Several factors affecting copper and cobalt galvanic corrosion in barrier layer CMP are studied. The chelating agents such as H _ 2O _ 2 and FA-O chelating agents of H _ 2O _ 2 and FA-P _ O are studied, and their control mechanism is also studied. The experimental results show that the corrosion potential of cobalt is greatly affected by the pH value, but not by the corrosion potential of copper. The corrosion potential difference between copper and cobalt decreases with the increase of pH value. In alkaline environment, the H _ 2O _ 2 can reduce the corrosion potential difference between Cu and Co (the minimum can be reduced to 3 MV / L), which can effectively inhibit the occurrence of galvanic corrosion between Cu and Co; The addition of a proper amount of FA-O chelating agent in the H2O2-base electrolyte can reduce the corrosion potential difference between Cu and Co and play an important role in inhibiting the occurrence of Cu and Co galvanic corrosion.
【作者单位】： 河北工业大学电子信息工程学院;天津市电子材料与器件重点实验室;
【基金】：国家科技重大专项子课题资助项目(2016ZX02301003-004-007) 河北省自然科学基金青年基金资助项目(F2015202267) 河北工业大学优秀青年科技创新基金资助项目(2015007) 天津市电子材料与器件重点实验室资助项目
【分类号】：TN40
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本文编号：2002681