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. 14, 1989
Filed:
Nov. 16, 1988
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An alignment method usable in an apparatus for transferring images of a pattern of a mask onto different portions of a semiconductor wafer in a step-and-repeat manner, is disclosed. In this alignment method, positional deviation of at least one portion of the wafer with respect to the mask is measured and, on the basis of this measurement, the mask and the wafer are aligned with each other. After this,step-and-repeat exposure is executed. When the measurement of the positional deviation of the at least one portion of the wafer is unattainable, another portion of the wafer is selected and the deviation measurement is executed in respect to the selected portion. In another aspect of the invention, with regard to a rotational component of the deviation of the wafer, measurement and alignment are repeatedly executed until the rotational component becomes less than a predetermined value. Thereafter, the step-and-repeat exposure is initiated.