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:
Jan. 25, 2005
Filed:
Dec. 18, 2002
David W. Herod, Greenville, TX (US);
Youling Lin, Richardson, TX (US);
David W. Herod, Greenville, TX (US);
Youling Lin, Richardson, TX (US);
Rudolph Technologies, Inc., Flanders, NJ (US);
Abstract
A system and method for detecting defects in surface structures, such as those formed on semiconductor wafers. A light source, preferably a strobe light, provides illumination that is separated by a filter into a plurality of selected bandwidths. The light then is transported through a fiber optic cable to a diffuser, and from there directed toward the surface. A camera captures a plurality of images, each image formed by a separate portion of the electromagnetic spectrum. The images may be formed by either reflected or diffracted light, or both. The images may be stored or compared to an image of a calibration wafer.