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Potential Dependence of Competitive Adsorption of PEG, Cl-, and SPS/MPS on Cu: An In Situ Ellipsometric Study



Marlon L. Walker, Lee J. Richter, Thomas P. Moffat


Potential dependent adsorption of bis- (3-sodiumsulfopropyl disulfide) (SPS), 3-mercaptopropyl sulfonate (MPS), Cl , and polyethylene glycol (PEG) on evaporated Cu thin films was examined using in-situ spectroscopic ellipsometry at 0.65 VMSE, -0.75 VMSE and 0.85 VMSE under quiescent conditions. The adsorption for the thiol compound was similar at all potentials examined, but the adsorption of the disulfide increased at more negative potentials. The influence of Cl on the substrate was greatly diminished and PEG concurrently less strongly adsorbed at more negative potentials, as measured by ellipsometric responses. Both sulfur-containing species inhibited the specific adsorption of PEG in the presence of Cl and displaced pre-adsorbed PEG/Cl- layers. The displacement of pre-adsorbed PEG/Cl- layers by the disulfide compound was strongly potential dependent. At all potentials studied, the disulfide was less effective than MPS at displacement of pre-adsorbed PEG/Cl-.
Journal of the Electrochemical Society


chloride, Cu electrodepostion, in-situ ellipsomety, MPS, PEG, potential dependence, SPS


Walker, M. , Richter, L. and Moffat, T. (2008), Potential Dependence of Competitive Adsorption of PEG, Cl<sup>-</sup>, and SPS/MPS on Cu: An In Situ Ellipsometric Study, Journal of the Electrochemical Society (Accessed April 18, 2024)
Created October 16, 2008