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:
Mar. 21, 1989
Filed:
Feb. 12, 1988
Shuichi Yabu, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An exposure apparatus having a movable stage for carrying thereon a workpiece such as a semiconductor wafer and a laser interferometer system for measuring the position of the stage with respect to X and Y directions, is disclosed. The movement of the stage is controlled on the basis of the position measurement by use of the laser interferometer system, so that a pattern of a mask or reticle is transferred onto different portions of the workpiece in a step-and-repeat manner. One or more air-conditioning devices are provided to supply currents of air, being controlled at the same temperature, toward the stage and along the measuring paths of the laser interferometer system which are in the X and Y directions. This is effective to avoid spatial temperature irregularities, particularly along the measuring paths, with the result that the measuring accuracy of the laser interferometer system can be improved remarkably. Thus, the step-and-repeat exposures can be made with higher correctness.