NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Fourier Transform Infrared Spectroscopy of CF4 on the GEC Reference CellFourier Transform Infrared Spectroscopy (FTIR) has been used to characterize inductively coupled CF4 plasmas in a GEC Reference Cell in-situ In examining these FTIR spectra, several assumptions and approximations of FTIR analysis are addressed. This includes the density dependence of cross-sections, non-linear effects in the addition of overlapping bands and the effect of spatial variations in density and temperature, This analysis demonstrates that temperatures extracted from MR spectra may provide a poor estimate of the true neutral plasma temperature. The FTIR spectra are dominated by unreacted CF, accounting for 40-60% of the gas products. The amount of CF4 consumption is found to have a marked dependence on power, and is nearly independent of pressure in the range of 10-50 mtorr. Small amounts of C2F6 are observed at low power. Also observed are etching products from the quartz window SiF4 COF2 and CO which occur in approximately equal ratios and together account for less than 10% of the gas. The concentrations of these species are nearly independent of pressure. CFx radicals are below the detection limit of this apparatus (approx. 1012/cc).
Document ID
20010050106
Acquisition Source
Ames Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Rao, M. V. V. S.
Sharma, S. P.
Meyyappan, M.
Cruden, Brett A.
Arnold, Jim
Date Acquired
August 20, 2013
Publication Date
January 1, 2001
Subject Category
Geophysics
Funding Number(s)
PROJECT: RTOP 755-30-01
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available