FA Process: Fault Isolation, Mechanisms, & Solutions - Root cause analysis of Rapid Thermal Process contamination using FIB-SEM nanoprobe characterization
FA Process: Fault Isolation, Mechanisms, & Solutions - Root cause analysis of Rapid Thermal Process contamination using FIB-SEM nanoprobe characterization
Wednesday, November 19, 2025
Summary:
This paper investigates a cross-contamination issue in a Rapid Thermal Processing (RTP) tool resulting in significant yield loss on a DRAM product. The root cause analysis identified random, highly localized (100nm) phosphorous contamination in the p-type channel under NMOS gates, traced back to outgassing from a lot of wafers processing immediately prior to the affected wafers. Failure analysis techniques, including SEM nanoprobing, Electron Beam Induced Current (EBIC), chemical staining and STEM-EDS, confirmed the defect. This case study highlights the importance of comprehensive failure analysis and process history investigation in resolving difficult yield issues and improving future technology node mixing risk assessments.
This paper investigates a cross-contamination issue in a Rapid Thermal Processing (RTP) tool resulting in significant yield loss on a DRAM product. The root cause analysis identified random, highly localized (100nm) phosphorous contamination in the p-type channel under NMOS gates, traced back to outgassing from a lot of wafers processing immediately prior to the affected wafers. Failure analysis techniques, including SEM nanoprobing, Electron Beam Induced Current (EBIC), chemical staining and STEM-EDS, confirmed the defect. This case study highlights the importance of comprehensive failure analysis and process history investigation in resolving difficult yield issues and improving future technology node mixing risk assessments.