AVS 50th International Symposium
    Plasma Science and Technology Friday Sessions
       Session PS-FrM

Paper PS-FrM6
The Role of Chamber Dimension in Fluorocarbon Etching of SiO@sub 2@ and its Effects on Gas and Surface-Phase Chemistry

Friday, November 7, 2003, 10:00 am, Room 315

Session: Plasma-Surface Interactions: Etching
Presenter: E.A. Joseph, University of Texas - Dallas
Authors: E.A. Joseph, University of Texas - Dallas
B. Zhou, University of Texas - Dallas
S.P. Sant, University of Texas - Dallas
L.J. Overzet, University of Texas - Dallas
M.J. Goeckner, University of Texas - Dallas
B.E. Gnade, University of North Texas
Correspondent: Click to Email
The influence of plasma-wall interactions in a CF4 discharge and their symbiotic effect on processing of SiO2 has been explored as a function of chamber dimension using a modified gaseous electronics conference (mGEC) reference cell. By varying chamber wall diameter, 20-66 cm, and source-platen distance, 4 - 6 cm, the etch behavior of SiO2 and the resulting gas-phase chemistry change significantly. Results from in-situ spectroscopic ellipsometry show significant differences in etch characteristics, with etch rates as high as 700nm/min and as low as 150nm/min for the same self-bias voltage. Etch yields however remain unaffected by the chamber size variations. Fluorocarbon deposition rates are also highly dependent on chamber dimension and vary from no net deposition to deposition rates as high as 450 nm/min. Significant shifts in gas-phase properties such as electron density and electron temperature, as determined by Langmuir probe, are also measured while gas-phase in-situ multi-pass Fourier Transform Infra-Red spectroscopy (FTIR) is used to corrleate CF2, CF3 and CF4 gas-phase densities to CFx overlayer thickness and stoichiometry measured by x-ray photoelectron spectroscopy (XPS) and grazing angle total internal reflection (GATIR-FTIR). @FootnoteText@ This work is supported by a grant from NSF / DOE, CTS-0078669.