INSPECTION DEVICE FOR SURFACE OF WAFER

PURPOSE:To increase the speed of feedback by composing the title inspection device of a long-sized light source for oblique projection light tying line focuses in the direction rectangular to the direction of carrying of a wafer surface, a projection lens, a long-sized receiving lens receiving only irregular reflected light, a receptor, and a douser mutually making oblique projection light, irregular reflected light and reflected light independent. CONSTITUTION:Linear oblique projection light L emitted from a light source 10 is focussed on the surface of a wafer 1 placed onto a carrier 6 jagging in the direction (a) as line beams by a projection lens 11. When there is no dust and foreign matter on the surface of the wafer 1, oblique projection light L total-reflects on the surface of the wafer 1 and is changed into reflected light L', and the light is recognized as normal reflected light. When contaminated particles adhere on the surface of the wafer 1, oblique projection light L is turned into scattered light and one part thereof is converted into irregular reflected light L'' and condensed to a receptor 13 through a receiving lens 12, and an electric signal is generated from the receptor 13. The electric signal is fed back to a preprocess as an alarm, and the wafer is treated as an abnormal one while a countermeasure treatment is executed in the preprocess, and subsequent wafers are changed into nondefectives. Accordingly, the status of the adhesion of contaminated particles on all wafers is monitored, thus improving the yield of the wafers.