Photoresist Lifting Induced Oxide Bridge Defects

Oxide Bridge (OX BG) with wafer center signature was found in the back-end-of-line (BEOL) section of IC fabrication. The defect resembled lifted photoresist (PR) pattern and was uncovered to be related with the weak points at the scribe lines surrounding the active die area. The PR lifting OX BG was significantly reduced through optimizing the focus margin as well as fixing the weak points at the scribe lines.