Electrochemical measurements during the chemical mechanical polishing of tungsten thin films

E. A. Kneer, C. Raghunath, V. Mathew, Srini Raghavan, Joong S. Jeon

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

A polishing tool and a potentiostat were used to simultaneously polish and measure the direct current (dc) open-circuit potential and anodic polarization behavior of chemical vapor deposited tungsten films in the presence of various oxidants. Of the different oxidants tested at pH 1.5 or pH 4.4, (NH4)6Mo7O24 formed the most protective passive layer on tungsten. Even in the presence of the most aggressive oxidant, Fe(NO3)3, the dissolution rates of chemical vapor deposited tungsten were approximately 3 nm/min during abrasion, which is a very small fraction of typical removal rates reported for chemical mechanical polishing of tungsten. This indicates that electrochemical oxidation followed by abrasive removal of the oxidation product and dissolution may not be the primary mechanism for tungsten removal. Atomic force microscopy scans of polished tungsten films indicate that corrosion assisted fracture may be an important removal mechanism for tungsten during chemical mechanical polishing.

Original languageEnglish (US)
Pages (from-to)3041-3049
Number of pages9
JournalJournal of the Electrochemical Society
Volume144
Issue number9
StatePublished - Sep 1997

Fingerprint

Tungsten
Chemical mechanical polishing
polishing
tungsten
Thin films
thin films
Oxidants
dissolving
Dissolution
Vapors
vapors
Industrial Oils
Anodic polarization
electrochemical oxidation
Electrochemical oxidation
abrasion
abrasives
Polishing
Abrasives
Abrasion

ASJC Scopus subject areas

  • Electrochemistry
  • Surfaces, Coatings and Films
  • Surfaces and Interfaces

Cite this

Electrochemical measurements during the chemical mechanical polishing of tungsten thin films. / Kneer, E. A.; Raghunath, C.; Mathew, V.; Raghavan, Srini; Jeon, Joong S.

In: Journal of the Electrochemical Society, Vol. 144, No. 9, 09.1997, p. 3041-3049.

Research output: Contribution to journalArticle

Kneer, E. A. ; Raghunath, C. ; Mathew, V. ; Raghavan, Srini ; Jeon, Joong S. / Electrochemical measurements during the chemical mechanical polishing of tungsten thin films. In: Journal of the Electrochemical Society. 1997 ; Vol. 144, No. 9. pp. 3041-3049.
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