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:
Jan. 03, 2017
Filed:
Apr. 01, 2013
Hitachi High-technologies Corporation, Tokyo, JP;
Kenshiro Ohtsubo, Tokyo, JP;
Hidetoshi Nishiyama, Tokyo, JP;
Takahiro Jingu, Tokyo, JP;
Masaaki Ito, Tokyo, JP;
HITACHI HIGH-TECHNOLOGIES CORPORATION, Tokyo, JP;
Abstract
To improve sensitivity of a defect inspection, it is required to decrease influence of excessive diffraction from a spatial filter. Further, it is preferable to secure signal intensity from defects and particles as much as possible, while the influence of the excessive diffraction is decreased as much as possible. The present invention is characterized in setting a width of a spatial filter surface such that an unnecessary image caused by diffraction, that is, an intensity of the excessive diffraction is sufficiently small with respect to an intensity of a desired image. In the present invention, an SN ratio that is an index for deciding a width of the spatial filter is calculated from a region subjected to the influence of the excessive diffraction in an inspection image, and a width of a shield unit of the spatial filter is set so as to maximize the SN ratio.