METHOD FOR DETECTING PARTICLES ON A MATERIAL

摘要

Impurities in a slice of semiconductor can cause electrical problems such as open circuits, short circuits etc., when the slice is used. This apparatus is used to count and measure these impurities so that badly polluted areas or whole slices can be discarded before further manufacturing processes. The polluted areas which can be detected range from 0.3 to 20 microns in diamter. A collimated beam of light from an arc lamp is directed through a lens and mask onto the slice, via a mirror and an iris. The light reflected from the slice is detected by a T.V. camera.