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:
Nov. 08, 2005
Filed:
Feb. 11, 2003
Michael Binnard, Belmont, CA (US);
W. Thomas Novak, Hillsborough, CA (US);
Toshio Ueta, Menuma-machi, JP;
Bausan Yuan, San Jose, CA (US);
Michael Binnard, Belmont, CA (US);
W. Thomas Novak, Hillsborough, CA (US);
Toshio Ueta, Menuma-machi, JP;
Bausan Yuan, San Jose, CA (US);
Nikon Corporation, Tokyo, JP;
Abstract
A wafer stage countermass assembly generally includes a base supporting one or more stages and first and second countermasses. The first and second stages move in one or more degrees of freedom. The countermasses move in at least one degree of freedom and, under ideal conditions, move to counter the movement of the stages in operation and thus preserve the systems center of gravity to avoid unwanted body motion. However, under actual conditions the countermasses may under travel or over travel their ideal trajectory. To more closely track the ideal trajectory, a controller actuates trim motors to apply small forces to the countermasses to push them towards a reference position in the Y direction. A second embodiment also takes into account the X position the stage(s) to cancel torque.