Validation procedures and results are presented for a model that simulates the erosion of large area three-dimensional patterns on semiconductor wafers during the chemical mechanical polishing process. The model, which is based on a pseudo-physical simulation of the contact and stress transfer between the pad and wafer, is reviewed. The validation results demonstrate that the model predicts the eroding topography to within experimental measurement error, implying that it faithfully captures the essential physical mechanisms at work on the feature-to-pattern scale during polishing.