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Microstructural and chemical properties of Cu‐In alloys formed using co‐electrodeposition
Author(s) -
Moon KyungWon,
Ashok Kumar A.,
Lee YoungBoo,
Park YangKyu,
Choi ChelJong
Publication year - 2012
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.4960
Subject(s) - overpotential , alloy , electrolyte , hillock , cathodic protection , diffusion , molar ratio , metal , materials science , metallurgy , chemistry , electrochemistry , electrode , composite material , catalysis , biochemistry , physics , thermodynamics
We investigated the microstructural and chemical properties of Cu‐In alloys formed on Au‐coated Si substrates using co‐electrodeposition. The co‐electrodeposition was performed using electrolytic solutions with various molar ratios of CuCl 2 and InCl 3 (1 mM/5 mM, 2 mM/4 mM, and 5 mM/5 mM) at room temperature. With increased electrodeposition current, the concentrations of Cu and In atoms in the Cu‐In alloys decreased and increased, respectively. Because of the preferential growth of Cu, a decrease in the molar ratio of CuCl 2 and InCl 3 led to a reduction in the minimum electrodeposition current that is required to obtain Cu‐In alloys with the same concentration of Cu and In atoms. The increases in electrodeposition current and the molar ratio of CuCl 2 and InCl 3 facilitated the formation of Cu‐In dendrites with long central trunks and secondary branches. The dendrites could be associated with autocatalytical alloy growth driven by a concentric diffusion field of metal ions on a thermodynamically unstable surface. During co‐electrodeposition using electrolytic solution (CuCl 2 = 1 mM and InCl 3 = 5 mM) under an electrodeposition current of 20 mA, the increase in the cathodic overpotential caused by surface irregularity led to the formation of Au‐In, which could be a main cause of the observed hillock formation. Copyright © 2012 John Wiley & Sons, Ltd.