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:
Mar. 26, 2002
Filed:
Feb. 03, 2000
Nimrod Sarig, Rosh Ha'avin, IL;
Gadi Greenberg, Tel Aviv, IL;
Applied Materials, Inc, Santa Clara, CA (US);
Abstract
A method and apparatus for inspecting the straightness of edges of features on a reticle is provided wherein the feature edges are analyzed for local defects as small groups of pixels, rather than pixel-by-pixel. In one embodiment, the reticle is imaged to produce pixels having a gray level and associated with an x and a y coordinate. A small array of pixels, such as a 2×2 array, that lays on an edge of the target feature is identified, a plane is calculated based on the x coordinate, the y coordinate and the gray level of each of the pixels in the array, and an angle &agr; between a reference line and a line at the intersection of the calculated plane and a reference plane is calculated. Several other edge-straddling arrays adjacent to the first array are identified, their respective angles &agr; are calculated, and all the &agr;'s are compared. If the &agr;'s are substantially equal, it is determined that the target feature edge is straight, and if the &agr;'s are not substantially equal, it is determined that the target feature edge is curved. A corresponding reference feature image is analyzed in the same way as the target feature image, and a defect is determined to exist in the target feature when the target feature edge is curved and the reference feature edge is straight.