Some Mechanical Models of Chemical-mechanical Polishing Processes

Chemical-mechanical polishing (CMP)-a perspective technology in fabrication of micro-and nanoelectronics elements, devices and systems. The development of models of CMP processes remains to be the actual problem. It is pointed out that known CMP models do not account for the features of chemical and mechanical mechanisms of interaction of active fluid and particles with a polished surface as well as an interaction of a viscoelastic pad with the surface. A description of the elementary acts of such interaction are absent in the available models. On the base of the analytical review of the current state of the theory and problems of (CMP) modeling some approaches were suggested to the problem accounting for the complex of the phenomena of different scales determining the polishing rate such as diffusion of slurry into the surface layer and restriction of time of chemical treatment of the surface by a rough pad being under the action of a mechanical load. A model of the CMP process was developed. Within the framework of this model a dependence of the polishing rate on the loading parameters was derived. The dependence generalizes the empirical Preston law.