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:
Aug. 20, 2002
Filed:
Dec. 09, 1999
Yoko Miyazaki, Tokyo, JP;
Masahiko Ikeno, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A defect inspection apparatus includes a first main controller for producing a reflectance distribution in a wafer surface to generate illumination light control data, based on the reflectance distribution, the illumination light control data being control data for adjusting the intensity of illumination light so that the intensity of reflected light from all locations in the wafer surface reaches an average intensity value, and a filter controller for inputting a filter control signal to a filter, based on the illumination light control data. The transmittance or reflectance of the filter for illumination light is controlled by the filter control signal. Consequently, the intensity of light reflected from a wafer to be inspected is controlled to provide uniformity in the wafer surface. Therefore, the defect inspection apparatus detects a defect occurring in the object to be inspected with high accuracy.