Degradation of poly(ethylene glycol-propylene glycol) copolymer and its influences on copper electrodeposition

Abstract

In this work, the degradation of poly(ethylene glycol-propylene glycol) copolymer (PEG-PPG) and its effect on the electrodeposition of Cu were investigated. PEG-PPG became fragmented during the electrodeposition with changing its terminal groups from hydroxyl to aldehyde, formic ester, and ketone. The aged solution showed a higher saturation current density than the fresh solution in chronoamperometry (CA) measurements, resulting from an easier desorption of the cleaved PEG-PPG from the copper surface through the competition with bis-(3-sulfopropyl)-disulfide (SPS). Furthermore, the electrical resistivity of Cu films deposited from the aged solution increased due to a decrease in the grain sizes. (C) 2014 Published by Elsevier B.V.