| 摘要 |
PURPOSE:To eliminate a dummy defect and detect only a true defect by performing enlarged image processing and density gradation conversion processing of reference image data and by performing defect inspection of a semiconductor wafer from difference image data between image data to be inspected and processed reference image data. CONSTITUTION:An image signal output from a visual sensor 18 is sent to an image processor 20. An A/D converter 23 converts the image signal from the visual sensor 18, and the digital image signal is stored in an inspection data memory 24 as image data to be inspected. A reference image memory 25 stores reference image data. An image processing unit 21 performs enlarged image processing and density gradation conversion processing on the reference data. A comparison unit 26 compares the image data to be inspected with the reference image data which has been subjected to enlarged image processing and gradation conversion processing to obtain difference image data. A host computer 28 determines a defect from the difference image data. |
