John Knoch - Portland OR, US Deborah Leek - Washougal WA, US Nathan Strader - Portland OR, US
International Classification:
G01N031/00
US Classification:
702030000
Abstract:
A method of qualifying a process tool includes steps of: (a) finding a plurality of pre-scan defect locations on a surface of a semiconductor wafer; (b) subjecting the semiconductor wafer to processing by the process tool; (c) finding a plurality of post-scan defect locations on the surface of the semiconductor wafer; and (d) calculating a plurality of defect locations added by the process tool from the pre-scan defect locations and the post-scan defect locations.
Michael Gatov - Gresham OR, US Deborah Leek - Washougal WA, US Bruce Whitefield - Camas WA, US
International Classification:
G06F 17/00
US Classification:
705400000
Abstract:
A method of determining a cost effective number of corrective tests to perform on a process experiencing process excursions. A test cost for each corrective test is determined, and a total test cost for each of an incremental number of corrective tests is calculated. An effect of each corrective test on a reduction in the process excursions is determined, as is also the lost revenue for each process excursion. A reduction in the lost revenue for each of the incremental number of corrective tests is calculated, based at least in part on the effect of each corrective test on the reduction in process excursions and the revenue lost for each process excursion. An overall cost for each of the incremental number of corrective tests is calculated, based at least in part on a sum of the total test cost and the reduction in the lost revenue for each of the incremental number of corrective tests. A minimum value of the overall costs is found, and that incremental number of corrective tests that is associated with the minimum value of the overall costs is selected as the cost effective number of corrective tests to perform.