A method for detecting defects in devices that are fabricated in
repetitive patterns upon the surface of a substrate by the, repetitive
utilization of masks and similar devices. A mask flaw will become
manifest in a series of defective devices as the mask is successively
utilized. The detection of repetitive defects is undertaken by
determining the electrical resistance of devices in a group, such as a
column, fabricated upon the wafer surface, where the repetitive defect
will occur multiple times. The mean electrical resistance of the group is
determined and a percent deviation of each device from the mean is then
determined. The percent deviation of all of the devices in the group are
multiplied together to create a multiplied percent deviation number and
the multiplied percent deviation number is then compared with a figure of
merit value to make a determination of whether defective devices exist
within the group.