Reduction characteristics of iodate ion on copper: Application to copper chemical mechanical polishing

Anik M.

Journal of Applied Electrochemistry, vol.34, no.9, pp.963-969, 2004 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 34 Issue: 9
  • Publication Date: 2004
  • Doi Number: 10.1023/b:jach.0000040549.05699.eb
  • Journal Name: Journal of Applied Electrochemistry
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.963-969
  • Keywords: CMP, copper, diffusion, iodate, kinetics, ELECTROCHEMICAL-BEHAVIOR, PLATINUM-ELECTRODES, SULPHURIC MEDIUM, ACID SOLUTIONS, TUNGSTEN, TECHNOLOGY, SURFACE, IODINE, DISK
  • Eskisehir Osmangazi University Affiliated: Yes

Abstract

Potentiodynamic and potentiostatic polarization, and the rotating disk electrode technique were used to study the reduction characteristics of iodate (IO3-) ion on copper (Cu). Depending on the relative concentrations of (IO3-) and H+. two pH regimes were observed. The cathodic current in the first regime (pH > 3) was controlled by H+ diffusion from the solution to the metal surface. In the second regime (pH < 3 and up to 10-2 M (IO3 -) concentration) the cathodic current was found to be under mixed control, involving reaction control via the electrochemical reduction of (IO3-) and transport control via the diffusion of I 2 (aq). It was concluded that (IO3-) was an effective oxidant for Cu chemical mechanical polishing (CMP) with strongly acidic (pH < 3) slurries but it was not convenient reagent as an oxidant for Cu CMP with weakly acidic (pH > 3) slurries.