| 摘要 |
In the case of die-to-die comparison, threshold processing units process the differential image between the image of a sample chip and the images of left and right adjacent chips using a second threshold value lower than a first threshold value thereby to determine a defect candidate for the sample chip. Further, threshold processing units process the differential image using the first threshold value. The defect candidates which develops a signal not smaller than the first threshold is detected as a defect. Also in the cell-to-cell comparison, the differential image is first processed by the second threshold value to determine a defect candidate, and the differential image is further processed by the first threshold value. The defect candidates which develops a signal not smaller than the first threshold value is detected as a defect.
|
