Electrodeposition of Copper in the PE-PEG-C1-SPS Additive System Reduction of Overfill Bump Formation During Cu Superfilling

Published

July 5, 2006

Author(s)

Soo K. Kim, Daniel Josell, Thomas P. Moffat

Abstract

The impact of Polyethyleneimine (PEI), a weak cationic polyelectrolyte, on the kinetics of copper deposition in the presence of additives used for superfill of sub-micron features is studied from deposition on planar substrates. The impact of PEI on overfill bump height during superfill of trenches in the same electrolytes is also studied. The observed dependence of overfill bump height as well and the general morphology of trench filling is interpreted in light of the kinetics studies. In summary, addition of PEI substantially quenches the additive-free Cu deposition kinetics; this is attributed to adsorption of PEI. A decrease in the hysteretic response of potential-current curves typical of superfilling electrolytes is observed in the presence of PEI; this is attributed to disturbance/deactivation of the accelerator by the PEI adsorption resulting from competition between PEI and the accelerator for adsorption sites. For certain concentrations, PEI effectively attenuates bump formation over superfilled features without significant negative impact on the superfill dynamic.

Citation

Journal of the Electrochemical Society

Volume

153

Issue

9

Pub Type

Journals

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Keywords

copper, Polyethyleneimine (PEI), superfill

Citation

Kim, S. , Josell, D. and Moffat, T. (2006), Electrodeposition of Copper in the PE-PEG-C1-SPS Additive System Reduction of Overfill Bump Formation During Cu Superfilling, Journal of the Electrochemical Society, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=853408 (Accessed April 25, 2024)