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. 15, 1988
Filed:
Apr. 08, 1985
Kyo Suda, Hachioji, JP;
Shigeharu Kimura, Kokubunji, JP;
Shinobu Hase, Hachioji, JP;
Chusuke Munakata, Tokyo, JP;
Kanji Kinameri, Tokyo, JP;
Yoshitoshi Ito, Ome, JP;
Hiroto Nagatomo, Tokyo, JP;
Yuzo Taniguchi, Higashimurayama, JP;
Mikihito Saito, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A pattern defect inspection apparatus detects presence or absence of a defect in a pattern formed on a semiconductor wafer by scanning the pattern normally to the surface thereof by a coherent light beam of a predetermined spot size, detecting reflected diffraction lights generated thereby and processing the detected lights. It comprises an abnormal direction signal detector including photo-detectors having wide light receiving areas arranged in a plurality of spatial areas which the reflected diffraction lights from a normal pattern do not normally reach, a normal pattern detector including photo-detectors having large light receiving areas arranged in a plurality of spatial areas which the reflected diffraction lights from the normal pattern reach, and a defect discriminator for determining if the abnormal direction signals are due to a true defect or not in accordance with the signals from the abnormal direction signal detector and the normal pattern detector.