Patent ID: 7061598
Filing Date: 2006-06-13
Classification: G01N

Abstract:
1. A darkfield surface inspection tool comprising; an illumination source for directing a light beam onto a workpiece to generate scattered light; a reflective light-shaping element that collects the scattered light from an illuminated portion of the workpiece and shapes the scattered light into a resultant light distribution so that the position of the light beams of the resultant light distribution is uniquely related to scattering angles of the received scattered light as the resultant light distribution reaches a photosensitive detector array and wherein the light-shaping element comprises a reflective ellipsoid surface having a first foci and a second foci having an imaginary line that passes through the first foci and the second foci; wherein the illuminated surface of the workpiece is at the first foci; and wherein the detector array is positioned so that the array directly receives the resultant light distribution from the light-shaping element but does not intersect with the second foci.