Patent ID: 7822260

Claim:
A method for inspecting an edge of a semiconductor wafer, the method comprising: placing a wafer in a semiconductor wafer inspection system; activating brightfield illumination on a first edge of the wafer; obtaining images of the first edge of the wafer for a first rotation of the wafer; analyzing the images of the first edge of the wafer for the first rotation and using the results of the analysis to focus a camera; deactivating the brightfield illumination; activating darkfield illumination on the first edge of the wafer; obtaining images of the first edge of the wafer for a second rotation of the wafer; obtaining images of a second edge of the wafer for the second rotation of the wafer; and analyzing the images of the first edge of the wafer for the first rotation, the images of the first edge of the wafer for the second rotation, and the images of the second edge of the wafer for the second rotation for wafer edge defects.