A specialty clustering option called Spatial Measures is available in the Hierarchical Cluster platform. In this example, you use this option to cluster wafers. For details about the option, see Spatial Measures.
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Select Analyze > Clustering > Hierarchical Cluster.
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Select Add Spatial Measures from the list of options in the lower left corner.
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Figure 10.8 Completed Clustering Launch Window
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Click OK.
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Figure 10.9 Spatial Components Window
Because Defects is measured at 1423 locations, there are 1423 Attributes variables.
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Click OK to accept the selections in the Spatial window.
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Click the red triangle next to Hierarchical Clustering and select Number of Clusters.
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Click the red triangle next to Hierarchical Clustering and select Cluster Summary.
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Figure 10.10 Cluster Summary Report
The wafer maps indicate the spatial nature of defects for each cluster. Cluster 1 contains 104 wafers with relatively few defects that are spread throughout the wafers. Cluster 3 has 5 wafers with defects concentrated at the extremes of the top and bottom hemispheres. You can view the maps for individual wafers and their Hough space maps in the data table produced by the cluster analysis. For more details, see Spatial Measures.