JPS644046A - Foreign matter inspection device - Google Patents

Abstract

PURPOSE:To reduce a generation frequency of a false report due to randomly generated noise by a method wherein inspection data of a foreign matter adhering to an object to be inspected is held and controlled and the held inspection data is processed by computation. CONSTITUTION:A whole area on the surface of a semiconductor wafer 2 is irradiated with a laser beam 4; the scattered light 7 generated by a foreign matter 6 is detected by using an optical detection device 8. An inspection data of the foreign matter 6 by this device is held by a data holding device 9. An inspection operation of the foreign matter 6 on the identical semiconductor wafer 2 is repeated two times. Normally, a false report due to noise or the like is included in the inspection data in addition to the inspection data obtained by an inspection of the scattered light from an actually existing foreign matter 6. If a first inspection result is compared with a second inspection result, there are the foreign body 6 detected in an identical position and the foreign matter 6 detected in a different position. In this case, the foreign matter 6 detected in the identical position during a second inspection is treated as the foreign matter 6 which actually exists in the position. The foreign matter 6 which is detected only once in the identical position is treated as the foreign matter 6 which does not exist actually and is treated as the false report due to the noise or the like.