Journal of the Electrochemical Society, Vol.147, No.8, 3094-3099, 2000
The influence of feature-scale surface geometry on CMP processes
The influence of feature-scale surface pattern dimensions on chemical mechanical polishing (CMP) processes has been studied through numerical simulations using a discretized geometry approach. The development of planarity for a symmetrical 3 X 3 array of square roughness elements with various lateral dimensions and spacing was simulated. Geometrical shielding of roughness elements by neighboring elements was found to cause asymmetrical surface polishing during the CMP processes. Given a specified trench spacing, a stronger doming effect was predicted for smaller sized protrusions. For a fixed feature size, the most significant doming effect was found to occur when the trench width is comparable to the gap size between the pad and the protrusion. These effects can be associated with variations in the flow pattern of the polishing slurry in the vicinity of the roughness elements.