Finite element analysis (FEA) of pad deformation due to diamond disc conditioning in chemical mechanical polishing (CMP)

Chemical mechanical polishing (CMP) is widely used to planarize semiconductor wafers and smooth the wafer surface. In CMP, diamond disc conditioning is traditionally employed to restore pad planarity and surface asperity. Despite the advancement of studies on diamond disc pad conditioning, there are very few published reports about the effect of diamond disc conditioning on pad deformation. A two-dimensional (2-D) axisymmetric quasi-static finite element analysis (FEA) model is proposed to investigate the interaction between the diamond disc conditioner and the polishing pad for the first time. The FEA model is developed by using the ANSYS software to study the effects of process parameters (conditioning pressure, pad thickness and pad hardness) on pad deformation. The study leads to a better understanding of the relationship between the diamond disc conditioner and the polishing pad in CMP. It also provides a basis for three-dimensional and dynamic analysis in the future. ©The Electrochemical Society.