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:
Feb. 16, 2010
Filed:
May. 16, 2007
Alan Torres Garcia, Singapore, SG;
Alan Torres Garcia, Singapore, SG;
Systems On Silicon Manufacturing Co. Pte. Ltd., Singapore, SG;
Abstract
In a first aspect according to the invention there is provided a sensing system, suitable for sensing the stage of processing of a wafer, said sensing systemcomprising receiving meansin the form of a first photosensitive deviceand a second photosensitive device, detector, a comparatorand a control system in the form of a programmable logic controller (PLC). The first photosensitive devicereceives light from the wafer, while the second photosensitive devicereceives ambient light. The light received by the first photosensitive devicecan be incident ambient light reflected off the surface of the wafer, refracted light radiating through the wafer, filtered light radiating through the waferor translucent light radiating through the wafer. It is further envisaged that the received light may be filtered through filters (not shown) before being received by the photosensitive devices&. The detectorthen generates a wafer control signal associated with the color(s) of the light received from the wafer. The wafer control signal produced by the detectoris then compared by a comparator. Once the comparatorhas compared the wafer control signal to the predetermined values, this indirectly indicates the level of processing of the wafer. The PLCthen controls the further processing of the waferaccording to the result of the comparison.