The challenges keep rising for fault isolation and failure analysis (FIFA) for the advanced semiconductor devices fabricated via integrated processes. Perceiving that defects randomly occurred during IC manufacturing contribute primarily to the device failures in comparison to those caused by harsh service environmental, we focus our efforts on fixing the defect issues in the processes, expecting a significant portion of the device failures may be prevented. A case study here demonstrates the procedure for fixing an inline defect issue via improving tool maintenance for the chemical-mechanical polishing (CMP) process. Through a correlative physical and chemical analysis down to atomic scale, a 10 nm diamond particle and a 10 nm metallic debris damaging one of the metal interconnect layers were defined. The analysis led to pinpointing the issue to a metal CMP process. By examining the process operation and the tool configuration, we located the diamond-missing sites on a pad-conditioning disk made with embedded diamond grits in a metal matrix. Preventive countermeasure were implemented to avoid the same defect recurring via resetting the disk life and maintenance.