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:
Sep. 20, 2011
Filed:
Nov. 29, 2007
Kazuo Tawarayama, Tsukuba, JP;
Kazuo Tawarayama, Tsukuba, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
According to an aspect of the present invention, there is provided a method of monitoring a focus position on a surface of a wafer for an exposure apparatus which transfers by exposure a pattern formed on a mask onto the wafer, including tilting at least one of the mask and an exposure area on the wafer and performing exposure while the mask and the exposure area have a relative angle, to form two spurious resolution images of the pattern of the mask in the exposure area; measuring positions of the two spurious resolution images formed in the exposure area and detecting an optimal focus position of the exposure apparatus on the basis of a middle point between the measured positions of the two spurious resolution images.