DFI Filler Cells – New Embedded Type of Test Structures for Non-Contact Detection of Electrical Defects on Product Wafers

A new type of test structures has been developed for process monitoring and defect detection on product wafers. The structures are part of PDF Solutions’ proprietary Design-for-Inspection™ (DFI) system. They electrically tested in a non-contact way using a dedicated and specially optimized e-Beam tool. They are designed to be compatible with standard cells and to be used as filler cells in standard cell-based logic designs. The paper presents the design and usage of such DFI structures as well as illustrated results collected from scanning product wafers containing embedded DFI filler cells.