US Patent 7193698 Wafer defect detection methods and systems

A wafer detection method. A plurality of PSL particles are sprayed on a wafer. An inspection operation is implemented on the wafer to obtain location information corresponding to a plurality of defects on the wafer, each location information corresponding to the defects comprises an error value. An inspection operation implemented on the PSL particles to obtain location information corresponding to the PSL particles. Offset location information corresponding to each defect is calculated according to the location information corresponding to each PSL particle. The error values corresponding to each defect are corrected according to the offset location information corresponding to each defect.