Wet cleaning of cross-contamination of high-k dielectrics in plasma etch tool

Viraj Pandit, H. G. Parks, Bert Vermeire, Srini Raghavan

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Direct tunneling through the gate SiO2 (εr ≈4) has become a serious concern for metal-oxide semiconductor field effect transistor scaling. The semiconductor industry is focusing on dielectrics with high relative dielectric constants (εr 10) to replace SiO2 gate oxides. Among the potential high- k materials, oxides and silicates of hafnium (Hf) have shown the most promise. The possibility of process cross-contamination by integrating these materials into silicon processes is a major concern for integrated circuit manufacturers. Cross-contamination of Hf in a plasma etch tool has been investigated. These studies confirm that significant cross-contamination occurs when HfO2 is etched in a chloro-fluoro-carbon plasma etch system. None of the standard cleaning processes commonly used in the semiconductor industry (such as SC1 and SC2) completely remove the contamination; however, dilute hydrofluoric acid, hydrofluoric acid-hydrogen peroxide water mixture, and SC1 cleans removed contamination below the concentration thresholds for oxide degradation and close to the total reflection X-ray fluorescence detection limit.

Original languageEnglish (US)
Article number017611JES
Pages (from-to)G970-G975
JournalJournal of the Electrochemical Society
Issue number11
StatePublished - 2006
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Materials Chemistry
  • Surfaces, Coatings and Films
  • Electrochemistry
  • Renewable Energy, Sustainability and the Environment


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