Comparison of defect size distributions based on electrical and optical measurement procedures

Defect size distributions play an important role in process characterization and yield prediction. To determine efficient procedures to extract defect size distributions, a database was set up that consists of hundreds of defect images to provide defect size distributions also reflecting irregular outlines of defects. Further investigation shows that even a single extension value per defect may provide a precise size distribution. Furthermore, the proposed Harp Test Structure (HTS) containing hundreds of parallel lines will also provide a defect size distribution, but it is based on electrical measurements only. The comparison of defect size distributions using both measurement procedures shows that not only optical measurements, but also electrical measurements at a Harp Test Structure are sufficient to obtain a precise defect size distribution that also enables size distribution modeling for yield prediction.