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In the absence of halogen ion, the convection-dependent competitive adsorption between bis(3-sulfopropy)-disulfide (SPS) and poly(ethylene glycol)-block-poly(propylene glycol) copolymer (EO/PO) on unpowered (in open circuit) copper surface is found in sulfuric acid solution. Galvanostatic measurements and electrochemical impedance spectroscopy were employed to analyze this particular adsorption behavior, revealing that the adsorption of EO/PO is enhanced by increased local convection intensity. The molecular dynamic simulation demonstrates that the increase of EO/PO adsorption decreases the adsorption of coexisting SPS on copper surface, supporting that the enhanced EO/PO adsorption in strong convection condition leads to the decrease of coexisting SPS adsorption on copper surface with the increase of convection intensity. The study of this convection-dependent competitive adsorption behavior enriches the understanding for the convection-dependent adsorption (CDA) behavior on electrolytic copper 'bottom-up' filling. Besides, the competitive adsorption behavior serves as a powerful handle to manipulate the accumulation of SPS at via or trench bottom before electroplating for improving the efficiency of via or trench filling. For example, the silicon wafer trench filling by copper electroplating is significantly accelerated with the introduction of convection-dependent competitive adsorption. Furthermore, a possible mechanism for accelerating trench filling by pre-adsorption process of SPS together with EO/PO is proposed. [ABSTRACT FROM AUTHOR]

In this paper, potentiodynamic cathode polarization, chronopotentiometry and galvanostatic measurement (GM) are applied to obtain electrochemical property of three levelers (oligomerswith different ratios of imidazole and 1,4-butanediol diglycidyl ether, named L1, L2 and L3, respectively) at different rotation speeds. Measured by GM with varied levelers, potential differences (PDs) are confirmed as effective indicators of THs plating and named Δη (caused by self-inhibition of leveler) and Δηr (caused by different convection). The slope of the Tafel curve, obtained by chronopotentiometry, is a bridge to connect PDs to uniformity of THs plating. Also, the multi-physical coupling simulation based on the finite element method is introduced to investigate leveling effect on uniformity. A model based on Haring cell is formulated to predict the relationship between PDs and uniformity. Furthermore, numerical simulation and plating experiment both show that levelers with more negative PDs lead to more uniform conformal THs copper deposition and a systematic relationship between PDs and uniformity of THs plating is established. The weightings of Δη and Δηr are also achieved for THs playing. Finally, the model paves an alternative way to screen for better leveler based on the relationship between PDs and uniformity of THs plating. [ABSTRACT FROM AUTHOR]