Published online by Cambridge University Press: 15 March 2011
This paper describes a new model, which analyzes the effects of the polishing conditions on nanotopography after polishing silicon (Si) substrates. The thickness uniformity of dielectric oxide-films after Chemical Mechanical Polishing (CMP) is affected by nanotopography of the Si substrate. Therefore, reducing nanotopography in Si substrates is essential in order to obtain highly uniform dielectric film thickness after CMP. We have developed a model based on Preston's equation for estimating the change in nanotopography of Si substrates due to polishing. In this model, various conditions relating to the structure of the polishing apparatus, the polishing pad material and the motion of the substrate can be taken into consideration. To investigate the influence of the polishing conditions on nanotopography, we compared experimental polishing results with calculations using this model. Thus, it was clarified that the generation of nanotopography in the polishing process that determines the final shape of the substrate, depends on the history of the pressure and contact distance produced during the process.