Displacement measurements in semiconductor wafer processing

Abstract

Wafers that begin as flat surfaces during a semiconductor manufacturing process may become warped or bowed as layers and features are added to an underlying substrate. This warpage may be detected between manufacturing processes by rotating the wafer adjacent to a displacement sensor. The displacement sensor may generate displacement data relative to a baseline measurement to identify areas of the wafer that bow up or down. The displacement data may then be mapped to locations on the wafer relative to an alignment feature. This mapping may then be used to adjust parameters in subsequent semiconductor processes, including adjusting how a carrier head on a polishing process holds or applies pressure to the wafer as it is polished. A model may be trained to provide control signals for a polishing/cleaning process, or to generate metrology data.