Method for detecting adjustment error in photolithographic stepping printer
Patent 6245584 Issued on June 12, 2001. Estimated Expiration Date: 
July 1, 2019. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 1, 2019. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesManufacturing system error detection Method for detecting malfunction in photolithographic fabrication track Patent #: 6051348 InventorsAssigneeApplicationNo. 09/346632 filed on 07/01/1999US Classes:438/14, WITH MEASURING OR TESTING382/144, Mask inspection (e.g., semiconductor photomask)382/145, Inspection of semiconductor device or printed circuit board382/149, Fault or defect detection382/151, Alignment, registration, or position determination430/30INCLUDING CONTROL FEATURE RESPONSIVE TO A TEST OR MEASUREMENTExaminersPrimary: Niebling, John F.Assistant: Luk, Olivia Attorney, Agent or FirmInternational ClassH01L 23/544 (20060101)AbstractAn adjustment error in a photolithographic stepping printer is detected by applying photoresist to a semiconductor wafer, and exposing the wafer to substantially identical light images in multiple locations using a stepping printer. The light images are defined by an optical reticle and include a plurality of lines or other features that are spaced from each other at approximately the resolution limit of the printer. Developer (16) is applied to the wafer to produce visible images corresponding to the light images. The visible images function as diffraction gratings which reflect light from the wafer. The visible images are inspected optoelectronically or manually. An adjustment error is determined to exist if the visible images appear substantially identical but are uneven or otherwise abnormal. |
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