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:
Oct. 10, 2017
Filed:
May. 12, 2016
Ultratech, Inc., San Jose, CA (US);
David G. Stites, St. Petersburg, FL (US);
Ultratech, Inc., San Jose, CA (US);
Abstract
Polarization-based coherent gradient-sensing systems and methods for measuring at least one surface-shape property of a specularly reflective surface are disclosed. The method includes: reflecting a first circularly polarized laser beam from a sample surface to form a second circularly polarized laser beam that contains surface-shape information; converting the second circularly polarized laser beam to a linearly polarized reflected laser beam; directing respective first and second portions of the linearly polarized reflected laser beam to first and second relay assemblies that constitute first and second interferometer arms. The first and second relay assemblies each use a pair of axially spaced-apart gratings to generate respective first and second interference patterns at respective first and second image sensors. Respective first and second signals from the first and second image sensors are processed to determine the at least one surface-shape property.