Diamond disc pad conditioning in chemical mechanical planarization (CMP): A surface element method to predict pad surface shape

Chemical mechanical planarization (CMP) is widely used to planarize semiconductor wafers and smooth the wafer surface. In CMP, a diamond disc conditioner is employed to condition (or dress) a polishing pad to restore the pad planarity and surface roughness. In this paper, a surface element method is proposed to develop a mathematic model to predict the pad surface shape resulted from diamond disc conditioning. The developed model is then validated by published experimental data. Results show that the model effectively simulates diamond disc conditioning and predicts the pad surface shape.

► A mathematical model for pad surface shape resulted from diamond conditioning.
► The pad surface shape is correlated to conditioner sweeping profile.
► There are some transition regions in the pad shape near the centre and periphery.
► The transition regions are caused by cumulative wear due to overlapped conditioning.