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US 2021/0342993 A1Published application
Wafer Bin Map Based Root Cause Analysis
AssigneePDF Solutions, Inc.
InventorsTomonori Honda, Lin Lee Cheong, Richard Burch, Qing Zhu, Jeffrey Drue David, Michael Keleher
Life of this patent
Estimating the term…
Abstract
A template for assigning the most probable root causes for wafer defects. The bin map data for a subject wafer can be compared with bin map data for prior wafers to find wafers with similar issues. A probability can be determined as to whether the same root cause should be applied to the subject wafer, and if so, the wafer can be labeled with that root cause accordingly.
Claims20
A method comprising:
- obtaining a first wafer bin map for a first semiconductor wafer manufactured in a current production run;
- identifying a product flow for the first semiconductor wafer;
- retrieving a plurality of prior wafer bin maps corresponding to prior production runs for semiconductor wafers manufactured using the identified product flow, and loading the plurality of prior wafer bin maps into a user interface;
- setting boundary conditions for a plurality of selected wafer parameters;
- comparing a first pattern on the first wafer bin map to a plurality of prior patterns respectively associated with the plurality of prior wafer bin maps in order to identify a subset of the plurality of prior wafer bin maps that have patterns similar to the first pattern of the first wafer bin map on the basis of the boundary conditions for the plurality of selected wafer parameters;
- determining a probability that a root cause associated with at least some of the subset of the plurality of prior wafer bin maps is a primary root cause for a defect associated with the first pattern on the first wafer bin map;
- and
- when the probability exceeds a threshold, assigning a label to the first wafer bin map indicating that the first root cause is the primary root cause.
5 more elements
A method comprising:
- receiving a first wafer bin map for a first semiconductor wafer manufactured in a current production run;
- retrieving a plurality of prior wafer bin maps corresponding to prior production runs for semiconductor wafers;
- computing a plurality of statistical distances between respective ones of the prior wafer bin maps and the first wafer bin map;
- assigning a single root cause to the first wafer bin map when each one of a subset of the plurality of prior wafer bin maps has a computed statistical distance less than a threshold and each one of the subset has the single root cause;
- and
- assigning a plurality of root causes to the first wafer bin map when each one of the subset has a computed statistical distance less than the threshold but each one of the subset does not have the first root cause, each of the plurality of root causes being assigned as a function of the computed statistical distance between respective ones of the prior wafer bin maps and the first wafer bin map.
3 more elements
Dependencies are inferred from the claim text.