Enhancement in Surface Finish by Modification of Basic Colloidal Silica with Silane in Chemical Mechanical Polishing

Chemical Mechanical Polishing (CMP) is an indispensible step in the Polishing of glass and ceramic surfaces. About 90% of semiconductor devices like integrated circuits (ICs) and Phase-change memory (PCM) device fabrication are done to attain globally planarized surface with good surface finish and excess material removal rate. One of the critical consumables in the CMP process is abrasive slurry containing both abrasives and chemicals acting together. To improve the chemical mechanical polishing performance, abrasive particles of Basic Colloidal silica was modified with Vinyl Tris(2-methoxyethoxy) silane (VTMS) through silanization reaction with surface hydroxyl group. The modified abrasive slurry exhibited a better dispersibility and stability in aqueous fluids which resulted in the improvement of surface finish in comparison to conventional process. The results of comparative study between pure basic colloidal silica slurry and modified slurry of VTMS + Basic Colloidal silica indicated a better surface finish quality with average Surface Roughness values(Ra) values in the range of 0.28 nm -0.41 nm on five samples when polished for four hours. (C) 2014 The Electrochemical Society.