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:
Aug. 19, 2008
Filed:
Dec. 31, 2003
Richard Burch, McKinney, TX (US);
Paul Lin, Shanghai, CN;
Spencer Graves, San Jose, CA (US);
Eric Antonissen, Redwood City, CA (US);
Richard Burch, McKinney, TX (US);
Paul Lin, Shanghai, CN;
Spencer Graves, San Jose, CA (US);
Eric Antonissen, Redwood City, CA (US);
PDF Solutions, Inc., San Jose, CA (US);
Abstract
A method for analyzing a sample of wafers includes identifying F failure metrics applicable to at least one pattern on each wafer within the sample. Z spatial and/or reticle zones are identified on each wafer, where Z and F are integers. Values are provided for each failure metric, for each zone on each wafer. A point is defined for each respective wafer in an N-dimensional space, where N=F*Z, and each point has coordinates corresponding to values of the F failure metrics in each of the zones of the corresponding wafer. The sample of wafers is partitioned into a plurality of clusters, so that the wafers within each clusters are close to each other in the N-dimensional space. A plurality of clusters is thus identified from the sample of wafers so that within each individual cluster, the wafers have similar defects to each other.