Measurements of radical densities in radio-frequency fluorocarbon plasmas using infrared absorption spectroscopy

M. Haverlag, E. Stoffels, W.W. Stoffels, G.M.W. Kroesen, F.J. de Hoog

Research output: Contribution to journalArticleAcademicpeer-review

70 Citations (Scopus)

Abstract

Densities of CF 2 radicals, rotational temperatures, and the degree of dissociation in radio-frequency fluorocarbon plasmas have been measured using Fourier transform infrared absorption spectroscopy and tunable diode laser infrared absorption spectroscopy. The CF2 densities obtained in CF4, CHF3fC2F6, and CF2C12 plasmas indicate that the partial pressure of CF2 is around l%-5% of the total pressure. From the spatial dependence of the CF2 density it was established that at high pressure, CF2 is produced either on the rf electrode or close to the rf electrode. Furthermore, a comparison between measured absorption spectra and a simulation of the rotational distributions has revealed that the rotational temperatures of CF4, CF2, and HF are all close to room temperature. FTIR spectra indicate that in plasmas of gases with a low F/C ratio (due to the presence of H or Cl) the source gas is converted for a significant part into other species.

Original languageEnglish
Pages (from-to)3102-3108
Number of pages7
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces, and Films
Volume12
Issue number6
DOIs
Publication statusPublished - 1 Jan 1994

Fingerprint Dive into the research topics of 'Measurements of radical densities in radio-frequency fluorocarbon plasmas using infrared absorption spectroscopy'. Together they form a unique fingerprint.

  • Cite this