(Invited) Material Removal Mechanism of Single and Polycrystalline Silicon in Alkaline Slurry

Abstract

The material removal characteristics of single and polycrystalline silicon in an alkaline regime under the same polishing conditions were investigated. The static and dynamic etch rates, and removal rates were measured as a function of slurry pH. The single silicon showed a higher static etch rate than the polycrystalline silicon. The friction force between pad and substrate and pad temperature was also measured as a function of pH during polishing in order to get more understanding of polishing process. At all the pH values being investigated, poly showed lower dynamic and removal rates, higher friction force and higher temperature. The results clearly show that the material removal mechanism of poly is different from that of single. This might be due to the presence of grain boundaries in poly which strongly interferes in the removal mechanism.