Discrimination of defects on epitaxial silicon wafers

The capability of fast defect type discrimination of defects on epitaxial Silicon wafers was investigated by correlating data of two different Surface Scanning Inspection Systems (SSIS) with results obtained by a Defect Imaging System (DIS). Comparing the assignment of defect type performed by the DIS to the light scattering data recorded by the SSIS reveals that the characteristic epitaxial defects - spikes, stacking faults and hillocks - often generate a light scattering intensity different from that of other defects. Almost 100% of the spikes, about 70% of the stacking faults and 40% of the hillocks were assigned to a separate defect class by one of the two SSIS. This defect discrimination is fast but not unique and it depends on the epitaxial defect type. However, the present investigation pointed out a potential for a fast, unique and complete defect discrimination by combining a SSIS with a DIS.