Effect of Slurry Chemistry on W CMP Performance

The removal mechanism of metal is firstly suggested by Kaufman[1]. In metal CMP, especially tungsten, a key step is W oxide formation on W Surface. Thus, the oxidizer is the most important component of slurry. Hydrogen peroxide (H2O2) that has a higher reduction potential is widely used as oxidizer. We could observe that slurry chemistries can affect to the CMP feature. The fundamentals of W CMP have not been fully understood. In this paper, the effect of slurry chemistry on W CMP performance such as tungsten oxide formation was investigated through surface analysis and electrochemical analysis.