咪唑对钌化学机械抛光的影响

利用自制的抛光液,研究了在磷酸体系抛光液中咪唑(imidazole,C3H4N2)浓度和pH值对钌的抛光速率的影响。采用电化学分析方法和X射线光电子能谱仪(XPS)分析了缓蚀剂咪唑对腐蚀效果的影响;采用原子力显微镜(AFM)观察钌片表面的微观形貌。试验结果表明:金属钌在未加入咪唑的磷酸体系抛光液中,抛光速率最高为6.2nm/min,平均粗糙度(Ra)为10.7nm;而在抛光液中加入咪唑后,钌的抛光速率为3.9nm/min,平均粗糙度(Ra)降至1.0nm。咪唑的加入,虽然降低了金属钌的抛光速率,但提高了金属钌的表面质量。同时也促进了金属钌表面钝化膜的生成,降低了金属钌的腐蚀电流值,抑制了阴极反应。

Effect of Imidazole on the Chemical Mechanical Planarization of Ruthenium

The effect of imidazole (C₃H₄N₂) concentration and pH value on the material removal rate (MRR) in H₃PO₄ slurries was investigated. The effect of inhibiter on the corrosion behavior was investigated by electrochemical methods and X-ray photoelectron spectroscopy (XPS). The surface roughness of the polished Ru disk was characterized by atomic force microscopy (AFM). The results show that the MRR can attain 6.2 nm/min and the surface roughness (Ra) of the polished Ru disk can reach 10.7 nm when Ru is in the H3PO4 slurries without imidazole. After adding imidazole, the MRR can reach 3.9 nm/min and Ra decreases to 1.0 nm. Imidazole can reduce the MRR of Ru, and obtain better surface quality. Polarization curves suggest that imidazole can promote the formation of the passive film on the surface of Ru, decrease the corrosion current and inhibit the cathode reaction.