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:
Feb. 03, 2004
Filed:
Oct. 19, 2000
Applicant:
Inventors:
David Peale, Tinton Falls, NJ (US);
Carlos Duran, San Diego, CA (US);
Harald Hess, La Jolla, CA (US);
Assignee:
KLA-Tencor Corporation, San Jose, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B 9/02 ;
U.S. Cl.
CPC ...
G01B 9/02 ;
Abstract
An interferometer that contains a tri-coupler to mix light from three different waveguides. The light is emitted from a light source and may be reflected from a test surface. The output of the tri-coupler may be three different light beams that have intensities 120 degrees out of phase from each other. The out-of-phase light beams may be detected by a plurality of photodetectors. The detected out-of-phase light beams may be used to determine a height of the test surface. The waveguides and tri-coupler provide a compact and relatively inexpensive interferometer.