The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 17, 2007
Filed:
Nov. 18, 2002
David W. Herod, Greenville, TX (US);
Kathleen Hennessey, Richardson, TX (US);
Youling Lin, Richardson, TX (US);
David W. Herod, Greenville, TX (US);
Kathleen Hennessey, Richardson, TX (US);
Youling Lin, Richardson, TX (US);
Rudolph Technologies, Inc., Flanders, NJ (US);
Abstract
A system and method for inspecting structures formed on the surface of an object using ultraviolet (UV) light. The object is placed in position and illuminated with at least one wavelength of UV light, directed at its surface from a UV source. At the moment of illumination, an image is captured by a UV-light sensitive camera positioned at an angle calculated to intercept light diffracted at particular an angle of diffraction associated with the pattern of structures formed on the surface of the object. To avoid having to repeatedly reposition the camera, one (or more in succession) illumination wavelength is selected to direct an intensity peak associated with a particular order of diffraction at the camera location. Ideally, a visible-light sensitive camera is also used to capture images of the surface when illumination with UV light results in the emanation of light in the visible portion of the spectrum.