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:
May. 22, 2007
Filed:
Oct. 14, 2005
Guoheng Zhao, Milpitas, CA (US);
Guoheng Zhao, Milpitas, CA (US);
3i Systems Inc., Sunnyvale, CA (US);
Abstract
Techniques for inspecting a substrate with improved defect sensitivity are disclosed. High sensitivity is achieved by reducing the noise due by using multiple laser beams for illumination, in which each beam is nearly collimated and illuminates uniformly a field of view. The images generated respectively by the laser beams are added incoherently by means of delivering the illumination beams incoherently in either time domain or space domain. According to one embodiment, all the illumination beams may not be interact with each other coherently so that the images generated by each laser beams can be summed together incoherently to average out possible excessive noise.