This thesis addresses selected unsolved problems in the chemical mechanical polishing process (CMP) for integrated circuits using ruthenium (Ru) as a novel barrier layer material. Pursuing a systematic approach to resolve the remaining critical issues in the CMP, it first investigates the tribocorrosion properties and the material removal mechanisms of copper (Cu) and Ru in KIO4-based slurry. The thesis subsequently studies Cu/Ru galvanic corrosion from a new micro and in-situ perspective, and on this basis, seeks ways to mitigate corrosion using different slurry additives. The findings presented here constitute a significant advance in fundamental and technical investigations into the CMP, while also laying the groundwork for future research.

Nominated by Tsinghua University as an outstanding thesis in the field Includes a detailed experimental analysis of the surface characterization of Cu interconnects Presents advanced experimental methods for investigating Cu/Ru micro-galvanic corrosion Explains the experimental results in detail

Inhalt
Introduction.- Material Removal Mechanism of Cu in KIO4-based Slurry.- Material Removal Mechanism of Ru in KIO4-based Slurry.- Tribocorrosion Investigations of Cu/Ru Interconnect Structure during CMP.- Micro-galvanic Corrosion of Cu/Ru Couple in KIO4 Solution.- Galvanic Corrosion Inhibitors for Cu/Ru Couple During Chemical Mechanical Polishing of Ru.- Synergetic Effect of Potassium Molybdate and Benzotriazole on the CMP of Ru and Cu in KIO4-based Slurry.- Conclusions and Recommendations.