Study on Material Removal Phenomena in CMP Process

Material removal phenomena in the CMP process have been considered as particles in slurry scratch material off from chemically reacted layer on wafer surface, produced by chemical agents in slurry. According to the molecular dynamics simulation, a particle sliding on single crystal silicon surface removes material in atomic size with cutting and produces amorphous layer on the surface. Furthermore, particle rolling on amorphous layer removes amorphous atoms with adsorption. However, the phenomena occurring on a wafer surface is not confirmed, and the CMP process simulation is also arduous to conduct. In the CMP process, material removal mechanism is determined by three dominant elements, which are wafer, polishing pad and slurry. In this research, we propose a material removal model, investigated into slurry particles' function on wafer surface and into the contact between wafer and polishing pad.