Patent ID: 9194795
Filing Date: 2015-11-24
Classification: G01N

Abstract:
1. A defect inspection apparatus comprising: a pulsed laser light source for emitting ultraviolet light; illumination optics for irradiating with the light a surface of a sample; first detection optics for forming a first enlarged image of the surface of the sample; an image sensor for detecting light scattered on the sample to acquire the first enlarged image of the sample; and an image processing unit for processing the first enlarged image of the sample; wherein: the pulsed laser light source comprises: a semiconductor laser as an oscillator; a signal source for generating pulse signals for driving the semiconductor laser; an amplifier disposed posterior to the semiconductor laser; and a wavelength converter configured to convert light amplified by the amplifier into the ultraviolet light, a spectral bandwidth of the semiconductor laser is controlled by changing a pulse length of each of the pulse signals, and a spectral bandwidth of the ultraviolet light emitted from the pulsed laser light source falls within a light-spectral bandwidth range permissible according to a particular chromatic aberration level of the illumination optics and a particular chromatic aberration level of the first detection optics.