DEFECT DETECTING APPARATUS AND METHOD FOR THEREOF

摘要

Provided is a defect detection apparatus capable of distinguishing between a defect residing on a substrate and a simple stain. According to an embodiment of the present invention, a defect detection apparatus comprises: a lighting unit to irradiate a substrate with light; a photography unit to obtain an image with respect to an edge region of the substrate by photographing the edge region of the substrate; a candidate region designation unit to designate a candidate region which a defect may exist of the edge region; a measurement unit to measure a brightness value of each pixel of the candidate region and a change of the brightness value; and a defect detection unit to determine that there is a defect in the candidate region if the change of the brightness value exceeds a predetermined threshold value.