Effect of wettability of poly silicon on CMP behavior

Abstract

The hydrophobicity of poly Si is reported to introduce different polishing behavior with careful control of post CMP cleaning process. The purpose of this study was to investigate the effect of poly Si wettability on its CMP behavior. The adhesion force of polymeric particle on the poly Si wafer surfaces was measured in the KOH solution (pH 11) as a function of solution A concentration. Adhesion force decreased and saturated as a function of concentration of solution A. The change of surface wettability affects not only the polishing rates but also the level of contamination on wafer because the interactions between particles and substrates are dependent on the wettability of the surface. Also, hydrophobic poly Si surfaces attracted much more pad particles with water marks than hydrophilic.