SIMULATION OF DIAMOND DISC CONDITIONING IN CHEMICAL MECHANICAL POLISHING: EFFECTS OF CONDITIONING PARAMETERS ON PAD SURFACE SHAPE

摘要

Diamond disc conditioning is traditionally employed to restore pad planarity and surface roughness in chemical mechanical polishing (CMP). In this paper, a mathematic model is developed by using a surface element method to simulate and predict the pad surface shape resulted from diamond disc conditioning. The developed model is then validated by published experimental data. Three metrics (total thickness variation (TTV), bow and non-uniformity (NU)) are defined and utilized to evaluate the pad surface shape. Based upon the validated model, effects of conditioning parameters (including sweeping profile, pad rotating speed, conditioner rotating speed, and conditioner diameter) on the pad surface shape are further investigated and discussed.