Importance

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Abstract

Method and system for declustering semiconductor defect data in cooperation with wafer scanning tools. Classification codes are assigned to defect data stored in wafer scan records by first determining the local density of the defects within a preselected area of the wafer substrate and by determining the average density of all of the defects on the substrate. A search area is defined around a defect of interest, the search area having a radius proportional to the ratio of the local density to the average density. The defects are marked within the search area, and for each marked defect, a new search area is defined and additional defects are marked. At least one of the marked defects is then assigned with a 'cluster' classification code and the remaining defects within the search areas are assigned with a 'discardable' classification code. By increasing the search radius linearly as the density ratio increases, the system automatically and more accurately removes noise in defect data caused by wafer scratches and other defect clusters.

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First Claim