MEASUREMENTS OF RADICAL DENSITIES IN RADIOFREQUENCY FLUOROCARBON PLASMAS USING INFRARED-ABSORPTION SPECTROSCOPY

Citation
M. Haverlag et al., MEASUREMENTS OF RADICAL DENSITIES IN RADIOFREQUENCY FLUOROCARBON PLASMAS USING INFRARED-ABSORPTION SPECTROSCOPY, Journal of vacuum science & technology. A. Vacuum, surfaces, and films, 12(6), 1994, pp. 3102-3108
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics, Applied","Materials Science, Coatings & Films
ISSN journal
0734-2101
Volume
12
Issue
6
Year of publication
1994
Pages
3102 - 3108
Database
ISI
SICI code
0734-2101(1994)12:6<3102:MORDIR>2.0.ZU;2-T
Abstract
Densities of CF2 radicals, rotational temperatures, and the degree of dissociation in radio-frequency fluorocarbon plasmas have been measure d using Fourier transform infrared absorption spectroscopy and tunable diode laser infrared absorption spectroscopy. The CF2 densities obtai ned in CF4, CHF3, C2F6, and CF2Cl2 plasmas indicate that the partial p ressure of CF2 is around 1%-5% of the total pressure. From the spatial dependence of the CF2 density it was established that at high pressur e, CF2 is produced either on the rf electrode or close to the rf elect rode. Furthermore, a comparison between measured absorption spectra an d a simulation of the rotational distributions has revealed that the r otational temperatures of CF4, CF2, and HF are all close to room tempe rature. 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.