Electrochemical Mechanical Polishing of Copper with High Permittivity Abrasives
Electrochemical Mechanical Polishing of Copper with High Permittivity Abrasives
复制标题
高介电常数磨料铜的电化学机械抛光
DOI：
10.1080/10426914.2012.677900
复制
发表时间：
2013-02-01
影响因子：
4.8
通讯作者：
Yuan, Zewei
中科院分区：
文献类型：
--
作者：
Li, Weisi;Guo, Dongming;Yuan, Zewei
电化学机械抛光（ECMP）是一种很有前途的用于含低钾材料互连的低压铜平化方法。ECMP利用铜的阳极溶解来提高材料的去除率。然而，由于电化学溶解的选择性去除能力较差，在ECMP中通常不能接受表面粗糙度。不同介电常数磨料对ECMP的表面质量有不同的影响。高介电常数磨料可以通过强化电极/电解质界面的电位降来增强选择性去除能力，从而获得更好的抛光效果。本文通过抛光实验对三种介电常数不同的磨料进行了比较。结果表明，金红石型TiO2的介电常数大于锐钛型TiO2和SiO2，在三种磨料中表面质量最好。优化了金红石型TiO2电解质的组成，提高了抛光性能。所选电解质含有0.5 mol/L甘氨酸、0.1 mol/L TSA、1wt %金红石TiO2。该电解质对材料的去除率为0.06 mg/min，表面粗糙度为Ra8.9 nm。
Electro-Chemical Mechanical Polishing (ECMP) is a promising low-pressure copper planarization method for the interconnection containing low-k material. ECMP utilizes anodic dissolution of copper to raise the material removal rate. However, the surface roughness is usually not acceptable in ECMP because the selective removal ability of electrochemical dissolution is poor. Different permittivity abrasives have different influence on surface quality in ECMP. High permittivity abrasives can enhance selective removal ability to get better polishing results through aggrandizing the potential drop in electrode/electrolyte interface. In this article, three abrasives with different permittivity are compared using polishing experiments. The results show that rutile TiO2, permittivity of which is larger than anatase TiO2 and SiO2, gets the best surface quality among the three abrasives. The composition of electrolyte with rutile TiO2 was also optimized to improve polishing performance. The chosen electrolyte contains 0.5 mol/L glycine, 0.1 mol/L TSA, 1 wt% rutile TiO2. The material removal rate got by using this electrolyte is 0.06 mg/min and the surface roughness is Ra8.9 nm.