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. 21, 1992
Filed:
Jul. 17, 1990
Jiri Pecen, Palo Alto, CA (US);
Kenneth P Gross, San Carlos, CA (US);
Brian Leslie, Cupertino, CA (US);
George Kren, Los Altos Hills, CA (US);
Tencor Instruments, Mountain View, CA (US);
Abstract
A particle imager and method for imaging particles on surfaces of substrates. A surface is raster scanned by a collimated light beam and particles on the surface are detected by the scattered light caused by the particles. During a scan path the intensity of the scattered light is measured forming intensity traces and location addresses for the detected particles. Data from each scan path is stored in memory. The imager is pre-calibrated with a test wafer having light scattering marker points spaced at known positions thereon. Scanning the test wafer, a clock measures time elapsed from a start position to each marker point. The corresponding elapsed times and known address locations are stored in memory for reference during data collection.