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:
Mar. 30, 2004
Filed:
Oct. 23, 2001
Bryan Kevin Clark, Mountain View, CA (US);
Beyond 3, Inc., Fremont, CA (US);
Abstract
An optical inspection method and apparatus having an enhanced height sensitivity region and roughness filtering uses a Fabry-Perot cavity to increase the phase detection sensitivity for light reflected from surface defects having a height above a predetermined level. A partially reflective surface is inserted between an illumination subsystem and a surface under inspection. The position of the partially reflective surface with respect to the surface under inspection is adjusted to provide both filtering of defects below the predetermined level and enhance sensitivity for a region of defect heights above the predetermined level. The angular resolution of the inspection system is improved, providing far-field inspection that can detect small-profile defects having unacceptable heights. Media storage, semiconductor wafer and other precision surface manufacture may be improved by use of the techniques of the present invention.