A model for copper electroplating of through-silicon vias (TSV) is proposed based on the suppressor adsorption/desorption mechanism, with special emphasis on the bottom-up filling of these structures. The proposed model is applicable for both 2-component (suppressor and accelerator) and 1-component (suppressor only) Cu plating chemistries. Numerical simulation was performed for the filling of 5 μm (diameter) × 40 μm (depth) vias. Simulated Cu profiles and the corresponding dependencies on additive concentration are confronted with existing experimental results.

The desorption / adsorption of suppressor additive during Cu electroplating plays a critical role in the void-free filling of recessed features such as through-silicon vias (TSVs) used in 3-dimensional integration. A stochastic model was proposed for Polyethylene Glycol (PEG) as a suppressor additive in Cu electroplating. Using the proposed model, a program capable of simulating transient processes such as cyclic voltammograms (CVs) was developed. The steep change of current density due to suppressor desorption, as well as the characteristic hysteresis, observed in the CVs was shown in simulation. The dependency of PEG desorption / adsorption on various factors, including the bath composition, scan rate and molecular weight, was simulated. The simulation results were confronted side-by-side with the corresponding experimental measurements. An overall good qualitative match was shown.

Green, stable and wide electrochemical window deep eutectic solvents (DESs) are ideal candidates for electrochemical systems. However, despite several studies of their bulk properties, their structure and properties under electrified confinement are barely investigated, which hinders the widespread use of these solvents in electrochemical applications. In this letter, we explore the electrical double layer structure of 1:2 choline chloride-urea (Reline), with a particular focus on the electrosorption of the hydrogen

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