The effect of H2O2 and Ammonia sulfate on the CMP of Molybdenum

Conference: ICPT 2012 - International Conference on Planarization / CMP Technology
10/15/2012 - 10/17/2012 at Grenoble, France

Proceedings: ICPT 2012

Pages: 6Language: englishTyp: PDF

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Chen, Fei; Zeng, Xu; Xu, Jing-Bo; Lu, Hai-Sheng; Qu, Xin-Ping (State Key Lab of ASIC and System, Department of Microelectronics, Fudan University, Shanghai 200433, China)

The chemical mechanical polishing (CMP) of Molybdenum (Mo) using hydrogen peroxide based alkaline solution was investigated. The effects of pH value and the H2O2 concentration on the Mo polishing were studied. The static etching rate (SER) and polishing rate (PR) were much higher in the alkaline solution and H2O2 can greatly enhance both SER and PR of Mo. It is found that in the presence of AS, not only the PR of Mo increased, but also the ratio of PR to SER of Mo was increased. According to the electrochemical measurements and the X-ray photoelectron spectroscopy results, it is proposed that, AS can react with MoO4 2- to form soluble ammonium molybdate to promote the removal of Mo. Keyword: CMP Mo, Ammonia sulfate, hydrogen peroxide, alkaline slurry