In line SEM inspection for yield learning in a manufacturing fabricator

This paper describes a technique to use SEM inspection to correlate in line inspection to electrical test results. Optical in line inspections have been used for yield learning for several years; however, they have always missed certain electrical fails that are not detected until wafer final test. In addition, as device critical dimensions continue to shrink, the number of defects that are undetected optically increases significantly. A possible solution is to move the inspections to an SEM based tool. This paper describes the results of using an SEM for inspection and how well it correlates to electrical test data