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:
Oct. 29, 2002
Filed:
Aug. 03, 2001
Toshiaki Mugibayashi, Tokyo, JP;
Nobuyoshi Hattori, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A defect analysis method makes it possible to quantitative grasp the influence of the number of new defects of a single process on the yield of a device. After the presence or absence of a new defect due to a specified process in each chip is judged, and defectiveness or non-defectiveness of the chip is judged by an electric tester, a plurality of chips on a wafer are classified into four groups: {circle around (1)} non-defective chip with no new defect; {circle around (2)} defective chip with no new defect; {circle around (3)} non-defective chip with new defect; and {circle around (4)} defective chip with new defect, to obtained the number of new defective chips considered to be caused only by the new defect of the specified process; a critical ratio of the new defect of the specified process, at which a chip is considered to become defective; and the number of process defective chips considered to be caused by the specified process.