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:
Apr. 15, 2014
Filed:
Sep. 12, 2011
Takeshi Yamane, Tsukuba, JP;
Tsuneo Terasawa, Kawasaki, JP;
Takeshi Yamane, Tsukuba, JP;
Tsuneo Terasawa, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
According to one embodiment, in a method for inspecting a defect of an exposure mask, using an optical system which acquires a dark-field image, an arbitrary partial region where a uniform dark-field image is obtained on the mask is allocated at a defocus position to acquire an image. A detection threshold is decided using signal intensities of the acquired image and an area ratio between a desired inspection region and the partial region, so that a signal count indicating signal intensities greater than the detection threshold in the inspection region is less than a target false detection count. The mask is allocated in a just-in-focus position to acquire an image of the inspection region. A signal having a signal intensity of the acquired image, which indicates an intensity greater than the detection threshold, is determined as a defect.