Patent ID: 7177020

Claim:
An apparatus for detecting defects on a specimen, comprising: an illumination optical unit which obliquely projects a laser onto a region which is longer in one direction than in a direction transverse to said one direction on a surface of a specimen; a table unit which mounts said specimen and which is movable; a detection optical unit which detects light from said specimen illuminated by said laser with an image sensor while said table is moving; a signal processor which is separated from said illumination optical unit, said table unit and said detection optical unit, which processes a signal outputted from said image sensor of said detection optical unit, which converts the outputted signal to a digital signal, and which extracts defects of said specimen by comparing said converted digital signal with a reference digital signal; a display unit which displays information of defects extracted by said signal processor; and a filter which cuts off light scattered from repetitive patterns formed on said specimen by the projection of said laser onto said region which is longer in said one direction, wherein said filter has a plurality of linear patterns which shields light scattered from said repetitive patterns formed on said specimen, and wherein pitches between said plurality of linear patterns are adjustable; wherein said illumination optical unit, said table unit and detection optical unit are disposed at an inlet or outlet of at least one processing apparatus in which the specimen is processed in a fabrication line for the specimen.