Mechanistic Studies of Cu Electropolishing in Phosphoric Acid Electrolytes

Electropolishing of Cu and Cu/Ta/Si wafer samples were studied using a rotating disk electrode in a variety of phosphoric acid-based electrolytes, including several with ethanol and other species added as diluents. Diluents allow a wide range of water concentrations to be accessed and also reduce th...

Full description

Saved in:
Bibliographic Details
Published inJournal of the Electrochemical Society Vol. 151; no. 6; pp. C375 - C378
Main Authors Du, Bing, Suni, Ian Ivar
Format Journal Article
LanguageEnglish
Published Pennington, NJ Electrochemical Society 2004
Subjects
Cross-disciplinary physics: materials science; rheology
Exact sciences and technology
Materials science
Physics
Surface treatments
Phosphoric acid
Aqueous solutions
Transition elements
Electropolishing
Surface treatments
Diffusion coefficient
Copper
Kinematic viscosity
Current density
Online AccessGet full text

Cover

More Information
Summary:Electropolishing of Cu and Cu/Ta/Si wafer samples were studied using a rotating disk electrode in a variety of phosphoric acid-based electrolytes, including several with ethanol and other species added as diluents. Diluents allow a wide range of water concentrations to be accessed and also reduce the dissolution rate during Cu electropolishing, simplifying possible applications to damascene processing. The measured limiting current densities are subject to a Levich analysis, demonstrating that water is the acceptor species involved in the rate-determining step. The effective diffusion coefficient that is determined is in almost exact agreement with that previously obtained from the electrohydrodynamic impedance, which does not require knowledge of the limiting species.
Bibliography:ObjectType-Article-2
SourceType-Scholarly Journals-1
ObjectType-Feature-1
content type line 23
ISSN:0013-4651
DOI:10.1149/1.1740783