中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 35 No. 1 January 2025 |
（1. College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310023, China;
2. Key Laboratory of Special Purpose Equipment and Advanced Processing Technology, Ministry of Education, Zhejiang University of Technology, Hangzhou 310023, China;
3. Adama Science and Technology University, Adama 1888, Ethiopia;
4. College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China）
Abstract:The Fenton-like reaction between Cu2+ and H2O2 was employed in chemical mechanical polishing to achieve efficient and high-quality processing of tungsten. The microstructure evolution and material removal rate of tungsten during polishing process were investigated via scanning electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectrophotometry, and electrochemical experiments. The passivation behavior and material removal mechanism were discussed. Results show that the use of mixed H2O2+Cu(NO3)2 oxidant can achieve higher polishing efficiency and surface quality compared with the single oxidant Cu(NO3)2 or H2O2. The increase in material removal rate is attributed to the rapid oxidation of W into WO3 via the chemical reaction between the substrate and hydroxyl radicals produced by the Fenton-like reaction. In addition, material removal rate and static etch rate exhibit significantly different dependencies on the concentration of Cu(NO3)2, while the superior oxidant for achieving the balance between polishing efficiency and surface quality is 0.5 wt.% H2O2 +1.0 wt.% Cu(NO3)2.
Key words: chemical mechanical polishing; tungsten; Fenton-like reaction; hydroxyl radical; material removal mechanism
