Ya-Bing Li, Wei Wang, Yong-Lei Li
Apr 1, 2009
Citations
1
Influential Citations
58
Citations
Journal
Journal of The Electrochemical Society
Abstract
The adsorption behavior and mechanism of Janus green B (JGB) during a copper via-filling process were investigated by means of electrochemical measurements. Mass spectrometry and liquid NMR spectroscopy were employed to confirm the molecular weight and the structure of a JGB decomposition product (noted simply as product A). Meanwhile, quantum chemistry calculation was also used to investigate the active atoms in a JGB molecule. These results suggest that JGB can be easily reduced to product A on the cathode surface at very low polarizing potential, and desorb from the cathodic surface at the same time. As a result, the double bond -N=N- in the JGB molecule is broken and two hydrogen ions are added to each nitrogen atom, respectively. Compared to JGB, the adsorption strength of product A increases with the potential shifting negatively, and only product A can adsorb on the cathodic surface stably in a high overpotential range, which corresponds to the potential range used in practical copper via filling. It can be concluded that the reduced product A of JGB is the real leveler of copper via filling.