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. 09, 1999
Filed:
Oct. 24, 1996
Michael R Sogard, Menlo Park, CA (US);
John K Eaton, Stanford, CA (US);
Kyoichi Suwa, Tokyo, JP;
Naoyuki Kobayashi, Tokyo, JP;
Nikon Corporation, , JP;
Abstract
A local air duct directs a temperature-controlled stream of air across two perpendicular sets of interferometer beams which are used to measure the two dimension (X-Y) position of a precision stage in e.g. an optical lithography stepper or step and scan system, or in any other precision coordinate measuring machine. By thereby providing an additional single air flow which is azimuthally directed across both the X and Y direction interferometer beams, the precision of the interferometric measurement is maximized. In addition, a second flow of air is directed downwards from the local air duct, thus providing sufficient air circulation onto the stage when the stage is directly beneath the local duct, even though in that location the stage is otherwise blocked from receiving the main air flow through the chamber.