HIGH-RESOLUTION INFRARED-SPECTROSCOPY OF ETCHING PLASMAS

Citation
M. Haverlag et al., HIGH-RESOLUTION INFRARED-SPECTROSCOPY OF ETCHING PLASMAS, Plasma sources science & technology, 4(2), 1995, pp. 260-267
Citations number
19
Categorie Soggetti
Phsycs, Fluid & Plasmas
ISSN journal
09630252
Volume
4
Issue
2
Year of publication
1995
Pages
260 - 267
Database
ISI
SICI code
0963-0252(1995)4:2<260:HIOEP>2.0.ZU;2-J
Abstract
Infrared absorption spectroscopy has been used to measure the absolute densities of neutral particles in various fluorocarbon RF plasmas. Th e densities of CF2 radicals have been measured using a tunable diode l aser. Moreover, broadband absorption spectra obtained using a Fourier transform spectrometer have been used to determine the densities of st able reaction products and to assess the degree of dissociation in the plasma. The results indicate that the rotational temperatures of all species involved are slightly above room temperature. The density of C F2 at high gas pressures increases close to the electrodes, indicating production near or on the electrodes and loss in the gas phase. The d issociation degree in plasmas of gases with a high C/F ratio can be as high as 90%. From an analysis of the flow dependence of the degree of dissociation the total dissociation rate coefficients of CF4, CF2Cl2, CF3Cl and C2F4Cl2 have been calculated.