Automated klarf-based defect inspection by electron-beam inspection tool: a novel approach to inline monitoring and/or process change validation

We report an optical inspection guided e-beam inspection method for inline monitoring and/or process change validation. We illustrate its advantage through the case of detection of buried voids/unlanding vias, which are identified as yield-limiting defects to cause electrical connectivity failures. We inspected a back end of line (BEOL) wafer after the copper electro plating and chemical mechanical planarization (CMP) process with bright field inspection (BFI) and employed EBI to inspect full wafer with guidance of BFI klarf file. The dark voltage contrast defects were detected and confirmed as buried voids by transmission electron microscopy (TEM).