Maintaining reproducible plasma reactor wall conditions: SF6 plasma cleaning of films deposited on chamber walls during Cl2/O2 plasma etching of Si

Saurabh J. Ullal, Harmeet Singh, John Daugherty, Vahid Vahedi, Eray S. Aydil

Research output: Contribution to journalArticle


The removal of silicon oxychloride films deposited on the chamber walls during Cl2/O2 plasma etching of Si using an SF6 plasma was studied using multiple surface and plasma diagnostic techniques. Focus was on the changes in the gas phase and in the chemical composition of the silicon oxychloride film as it is removed by F atoms in an SF6 plasma. Films depositing and species adsorbing on the chamber walls during the deposition and cleaning steps were detected by a real time, in situ diagnostic probe. The radicals in the discharge were detected by optical emission spectroscopy (OES) while stable gas species present in the exhaust of the reactor were detected through gas phase FTIR absorption spectroscopy. Simultaneous monitoring of the walls and the gas phase yielded insights into the cleaning mechanism of the silicon oxychloride deposits by SF6 plasma.

Original languageEnglish (US)
Pages (from-to)1195-1201
Number of pages7
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Issue number4
StatePublished - Jul 1 2002


ASJC Scopus subject areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

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