A method of analyzing substrate yield, where a substrate yield map and a substrate
contact map are selected and overlaid to produce a composite map. First elements
of the substrate yield map are compared to second elements of the substrate contact
map to determine a degree of correlation between the first elements and the second
elements. Additional substrate contact maps are repeatedly selected and the first
elements of the substrate yield map are compared to the second elements of the
additional substrate contact maps, and a degree of correlation between the first
elements and each of the second elements for the additional substrate contact maps
is determined and reported. The composite map having a highest degree of correlation
between the first elements and the second elements is presented, and all composite
maps that have at least a desired degree of correlation between the first elements
and the second elements are presented.