Patent ID: 6686994
Filing Date: 2004-02-03
Classification: G01N,G02B,G02F

Abstract:
An optical inspection system for detecting anomalies on a sample, comprising:a light source for directing an incident light beam having a wavelength between about 340 nanometers and 400 nanometers onto a sample; a programmable spatial filter (PSF) arranged in a path of light emanating from the sample in response to the incident light beam, the PSF being constructed from materials wherein when a voltage potential difference is applied to or removed from the materials, the materials have either an opaque property to thereby inhibit at least a first portion of the emanating light with a minimum extinction value of about 400:1 or have a transparency property to thereby transmit at least at least a second portion of the emanating light with a minimum transmission value of about 40 percent for the incident light beam; a detector arranged within the path of the emanating light so that the second portion of the emanating light that is transmitted by the PSF impinges on the detector to thereby form an image of at least a portion of the sample; and an analyzer for receiving the image and determining whether there are any defects present on the sample portion by analyzing the received image.