碱性抛光液中螯合剂对Cu/Ta电偶腐蚀的影响（英文）

Effect of the ChelatingAgent in the Alkaline PolishingSlurryon the Galvanic Corrosion Between Cu and Ta

铜钽(Cu/Ta)界面在化学机械抛光(CMP)中易发生电偶腐蚀。研究了碱性抛光液中螯合剂对铜钽开路电位以及抛光速率的影响。利用静态与动态下的电化学方法,分别测得开路电压和动电位极化曲线,表征了铜钽分别在不同螯合剂体积分数的抛光液中的化学反应速率。CMP结果表明,随着螯合剂体积分数的增加,铜的去除速率不断增加,而钽的去除速率先增加后降低。同时,通过静态腐蚀实验和表面状态表明,随螯合剂体积分数增加,铜表面络合反应加快,而钽表面钝化加重。当螯合剂的体积分数为0.2%时,在动态情况下,铜钽之间腐蚀电位差降到0mV,表明螯合剂可以极大地降低Cu/Ta电偶腐蚀。

Galvanic corrosion occurs easily at the interface of Cu and Ta in the process of chemical mechanical polishing（CMP）.The effects of the chelating agent in the alkaline polishing slurry on the open circuit potential and removal rates of Cu and Ta were investigated.The open circuit potential and potentiodynamic polarization curves were measured by the electrochemical method in static condition and dynamic condition,characterizing the chemical reaction rates of Cu and Ta in the slurries with different volume fractions of the chelating agent.The CMP results show that with the increase of the volume fraction of the chelating agent,the removal rate of Cu increases,but the removal rate of Ta increases firstly and then decreases.Meanwhile,the static corrosion experiment and surface topography show that with the increase of the chelating agent volume fraction,the complexation of the Cu surface increases,while the passivation of the Ta surface increases.When the volume fraction of the chelating agent is 0.2%,the corrosion potential difference between Cu and Ta decreases to 0mV under the dynamic condition,revealing that the chelating agent can significantly reduce the galvanic corrosion between Cu and Ta.