Patent ID: 11972552
Assignee: PDF SOLUTIONS, INC.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 19:
20. A method comprising
obtaining a first plurality of sample images of semiconductor wafers formed on a semiconductor substrate, the first plurality of sample images including a plurality of different image types;
computing, a plurality of single-dimension metrics each corresponding to a respective one attic plurality of sample images, each metric each defining a plurality of features for the respective sample image;
performing, variable selection on each metric in order to select a smaller set of features from the plurality of features that are more important in determining image type for the metric;
processing each corresponding metric in a plurality of machine-learning-based pairwise classifier models, each of the pairwise classifier models configured to determine a corresponding probability that the metric is more indicative of one of a unique plurality of pairs of the plurality of different image types; and
running a final machine-learning-based classifier model configured to assign one of the plurality of image types to each corresponding vector on the basis of the determined probabilities from the processing step.