To provide a method for efficient inspection of a defect in a laminated layer on the surface of a semiconductor wafer in non-destructive manner.
A surface of a semiconductor wafer 1 is conceptually divided into a plurality of cells. A light spot 41 formed on the surface of the wafer 1 is scanned with movement of a stage 10. The cells illuminated with the spot 41 are image picked up by a high-speed image sensor 19 and sequentially stored alternately in image memories 20 and 21 by cell units. An image processor 22 compares the images of the image memories 20 and 21 and finds out a non- matching part therebetween to thereby detect a laminated layer defect present on the surface of the wafer 1. The processor distinguishes between the laminated layer defects and other abnormalities on the basis of the shape of the non- matching part.
YOSHIDA YOSHIKO
YAMAMOTO HIDEKAZU
