Lay summary
The present project aims to develop new concepts for the superfill (bottom-up fill) of large, µm-sized copper interconnects that are mandatory for the future three-dimensional Through-Silicon-Via (3D-TSV) technology. This technology allows the 3D stacking of individual microprocessors and the integration of memory devices and other applications on one single processor unit. Copper deposition for such interconnects requires new types of chemistries that form stable suppressor ensembles at the wafer surface and the upper sidewalls of the TSV features during the entire superfill. Firstly, new suppressor additives will be synthesized based on the polymerization of various diglycidyl ethers and bivalent bases. Secondly, these polymers will be characterized by different analytical and electrochemical methods in order to obtain information on the particular polymer structure, the molecular weight/size distribution, the suppressing capabilities and the overall electrochemical stability under reactive conditions. Thirdly, the active suppressor ensemble will be isolated, identified and characterized with various spectroscopic and microscopic methods (EC-STM, MS, UV-VIS, SQUID, elementary analysis) in order to gain a fundamental atomistic understanding on the formation and the action mode of the suppressor ensembles at the copper/electrolyte interface. The copper deposition will finally be performed with the new suppressor polymers on real 3D-TSV test structures. The quality of the fill will be characterized by different wafer-scale analytic methods. The project is going to contribute a significant fundamental knowledge for the development of suppressor additives that will be applied for the future 3D-TSV technology in the semiconductor industry.