Patent ID: 7567343
Filing Date: 2009-07-28
Classification: G01N

Abstract:
1. An apparatus for detecting defects, comprising: a laser-beam light source which emits an ultraviolet pulsed laser beam; an irradiation optical unit which expands a diameter of the ultraviolet pulsed laser beam with a beam expander, converts a shape of the ultraviolet pulsed laser beam to be converged in one direction and collimated in another direction with a cylindrical lens and obliquely irradiates a linear area of a specimen; a detection optical unit that forms an optical image by a light reflected from the linear area of the specimen irradiated by the irradiation optical unit and picks up the formed optical image with an image sensor; and a signal processing unit which processes the optical image obtained with the image sensor to detect defects of the specimen, including defects having sizes less than 0.1 μm; wherein the irradiation optical unit divides the ultraviolet pulsed laser beam emitted from the laser beam light source into a plurality of pulses and converts the shape of the plurality of pulses, using the cylindrical lens, to irradiate the linear area on the specimen.