CHU Xiang*, WANG Jie, DONG Yongping, QIAO Hongbin, ZHANG Wangbing
(School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002, China)
Abstract: In this paper, chemical mechanical polishing behaviors of Ruthenium(Ru) in hydrogen peroxide (H2O2)-based slurry are investigated. The effect of the oxidizing agent and complexing agents on the corrosion behaviors are investigated by using electrochemical measurement and X-ray photoelectron spectroscopy. And the polished Ru surface is characterized by atomic force microscopy. Results show that the tightness and thickness of the passive film on the surface of Ru are related to the concentrations of CH3COOH and H2O2. CH3COOH can accelerate the anode reaction and enhance the chemical action of the slurry on the surface of Ru. The material removal rate (MRR) of Ru in slurries with CH3COOH as complexing agent is higher than that of TEA or C4H6O6. H2O2 at low concentration promotes the chemical corrosion ability to corrode Ru surface and increases MRR, the increasing of H2O2 concentration may promote the formation of a thick oxide film on Ru surface, which reduces the corrosion rate and the MRR at higher concentration of H2O2. The XPS results suggest that the atomic ratio of Ru to oxide is about 2: 3 and Ru is oxidized to Ru4+ and Ru8+ just after the immersion of Ru into the H2O2-based slurry with CH3COOH because of the formation of RuO2 and RuO4 on the Ru surface. The roughness average (Sa) of Ru surface can be reduced from 33 nm to 6.99 nm after polished within 5 μm×5 μm area.
Key words: ruthenium; chemical mechanical planarization; electrochemical measuremen; hydrogen peroxide; complexing agents
E-mail: xfchu99@ahut.edu.cn
Tribology, Vol. 32, Issue 5, 2012, 421~427
