Abstract: A lithographic scanner collects surface height information concurrently with conducting a lithographic scan process. A defect identification module identifies wafers having a surface height metric greater than a determined threshold. The identified wafers may be separated for rework to correct the surface defects such as hotspots and improve manufacturing yield without requiring additional equipment. In one embodiment, the surface height metric is a maximum variation from a moving average surface height. In one embodiment, yield data is correlated with surface height information to determine a threshold value corresponding to defective circuit die.