A method for inspecting objects such as semiconductor wafers. A staging
platform and an optical platform are arranged so that the object may be
staged and its surface scanned by optical equipment situated on the
optical platform. During the scanning process, the surface is illuminated
with light of a plurality of wavelengths, each strobed at a predetermined
rate so that multiple images may be collected using time and frequency
multiplexing. The multiple images are stored in a database for analysis,
which includes processing selected ones of the multiple images according
to one or more algorithms. The defect-detection algorithms used for each
object are determined by referenced to a predetermined or calculated
defect detection protocol, then a defect mask is created for each pixel
in the images that is suspected to be defective. The defect mask is then
compared to threshold parameters to determine which if any of the
suspected defects should be reported.