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:
Aug. 22, 1995
Filed:
Dec. 03, 1993
Hirohisa Ohta, Sagamihara, JP;
Kunitaka Ozawa, Isehara, JP;
Eigo Kawakami, Ebina, JP;
Shunichi Uzawa, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An exposure method includes disposing a mask and a semiconductor wafer opposed to each other in a close proximity relation with respect to a Z-axis direction and printing a pattern of the mask on each of different shot areas of the semiconductor wafer in a step-and-repeat manner, with a predetermined exposure energy. In this method, the spacing between the mask and the wafer for the paralleling of them is made larger than the spacing therebetween as assumed at the time of mask-to-wafer alignment with respect to X-Y plane or the spacing between the mask and the wafer as assumed at the time of exposure of the wafer to the mask. After the paralleling of the mask and the wafer, the mask and the wafer are moved closer to each other in the Z-axis direction and alignment and exposure is performed. This ensures that the alignment and exposure are effected at an optimum spacing while, on the other hand, contact of the mask and the wafer at the time of paralleling is precluded.