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. 29, 2002
Filed:
Jun. 20, 2000
Evan F. Cromwell, Redwood City, CA (US);
Johann F. Adam, Palo Alto, CA (US);
Katsina Optics, Inc., Milpitas, CA (US);
Abstract
A laser scatterometer used, e.g., to detect defects on memory media, includes a beam block that can be finely adjusted so as to block specular light while maximizing the small angle scattered light that is received by the light detector. The beam block may be adjusted independently of the light detector or may be a masked beam block that is adjusted with the entire light detector. The light source produces a light beam that is focused so as to maximize the spot size on the object being tested while minimizing the spot size at the beam block, which advantageously maximizes the small angle scattered light while decreasing testing time. The large spot size at the object being tested permits detection of large defects. Thus, disks may be quickly tested, e.g., during the burnishing process, to determine if there are any large defects.