Microscopy Analysis and Material Characterization - Unraveling the Ni Multi-Moon Issue: A Cross-Functional Approach to Expose and Analyze Subsurface Defects
Microscopy Analysis and Material Characterization - Unraveling the Ni Multi-Moon Issue: A Cross-Functional Approach to Expose and Analyze Subsurface Defects
Wednesday, November 19, 2025
Summary:
In the ever-evolving landscape of semiconductor manufacturing, the ability to detect and analyze sub-micron and buried defects is paramount for yield improvement and reliability assurance. This study delves into a perplexing wafer defect observed at the RX and CT steps, characterized by distinctive half-moon or full-moon signatures at the wafer edge. Initially flagged through inline contamination-free manufacturing (CFM) inspection, the defect required deeper investigation to uncover its true nature and origin. Our cross-functional team, comprising experts from CFM, etch, and failure analysis (FA), embarked on a collaborative journey to tackle this challenge. Leveraging high-resolution techniques such as SEM, TEM, STEM, and EDX, we identified Ni-capped silicon spike structures, indicative of metallic contamination. To overcome the limitations of standard inspection tools, we developed an innovative etch-assisted hybrid inspection methodology. This approach enabled us to expose and analyze previously hidden defects, transforming them into analyzable features. The success of this investigation underscores the power of coordinated, cross-functional efforts and advanced FA techniques in solving complex defect mechanisms. Our findings provide critical insights into backside-to-frontside Ni diffusion and highlight the need for integrated inspection protocols to enhance process robustness and analytical capabilities in semiconductor manufacturing.
In the ever-evolving landscape of semiconductor manufacturing, the ability to detect and analyze sub-micron and buried defects is paramount for yield improvement and reliability assurance. This study delves into a perplexing wafer defect observed at the RX and CT steps, characterized by distinctive half-moon or full-moon signatures at the wafer edge. Initially flagged through inline contamination-free manufacturing (CFM) inspection, the defect required deeper investigation to uncover its true nature and origin. Our cross-functional team, comprising experts from CFM, etch, and failure analysis (FA), embarked on a collaborative journey to tackle this challenge. Leveraging high-resolution techniques such as SEM, TEM, STEM, and EDX, we identified Ni-capped silicon spike structures, indicative of metallic contamination. To overcome the limitations of standard inspection tools, we developed an innovative etch-assisted hybrid inspection methodology. This approach enabled us to expose and analyze previously hidden defects, transforming them into analyzable features. The success of this investigation underscores the power of coordinated, cross-functional efforts and advanced FA techniques in solving complex defect mechanisms. Our findings provide critical insights into backside-to-frontside Ni diffusion and highlight the need for integrated inspection protocols to enhance process robustness and analytical capabilities in semiconductor manufacturing.