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:
May. 06, 1986
Filed:
Oct. 18, 1983
John C Barker, Oakington, GB;
Ian A Cruttwell, Great Chishall, Nr. Royston, GB;
Cambridge Instruments Limited, Cambridge, GB;
Abstract
A defect detection system for classifying defects in reticles (such as used in the manufacture of integrated circuit wafers) is described. An inspection unit, scanning the reticle in real time, compares it with the correct form and inputs signals representing each defect and its position in a store. The stored defects are then used to direct the inspection unit to inspect each defect more slowly. The inspection unit classifies each defect as either being an 'excess metal' or a 'missing metal' defect, and corresponding signals are stored in respective additional stores. The signals stored in these stores are then further processed and compared with the desired form of the reticle so as to classify the 'excess metal' defects as either being a 'pin spot' defect, an 'extension' defect or a 'bridge-type' defect. Similarly, the 'missing metal' defects are classified as either being a 'pinhole' defect an 'intrusion' defect or a 'break-type' defect. A size measuring unit measures the size of each defect.