A study on the correlation between electrochemical corrosion and chemical mechanical polishing performance of W and Ti film

In this paper, in order to investigate the electrochemical polishing behavior of the tungsten (W) and titanium (Ti) film, the chemical mechanical polishing (CMP) performances of W and Ti film according to the oxidizer contents were studied through electrochemical corrosion analysis. The alumina (Al2O3)-based tungsten slurry with H2O2 oxidizer was used for CMP test. As an experimental result, for the case of 5 vol% oxidizer added, the removal rates were improved and a good polishing selectivity of 1.4 : 1 was obtained. It means that the oxidizer with the highest removal rate (RR) has a high dissolution rate due to the predominant electrochemical corrosion effects. Therefore we conclude that the W and Ti-CMP characteristics are strongly dependent on the amounts of H2O2 oxidizer additive.