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CH 3 and CH Densities in a Diamond Growth DC Discharge
Author(s) -
Menningen K. L.,
Childs M. A.,
Toyoda H.,
Ueda Y.,
Anderson L. W.,
Lawler J. E.
Publication year - 1995
Publication title -
contributions to plasma physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.531
H-Index - 47
eISSN - 1521-3986
pISSN - 0863-1042
DOI - 10.1002/ctpp.2150350405
Subject(s) - chemical vapor deposition , materials science , plasma , radical , diamond , analytical chemistry (journal) , absorption (acoustics) , atomic physics , absorption spectroscopy , cathode , carbon fibers , plasma diagnostics , optics , chemistry , nanotechnology , physics , organic chemistry , quantum mechanics , composite number , composite material
A highly sensitive multi‐element optical absorption technique is used to measure the absolute column density of both CH 3 and CH radicals in a dc hollow cathode plasma‐assisted chemical vapor deposition (CVD) system with CH 4 and H 2 used as the input gases. The plasma gas temperature is determined at different spatial points using the H 2 emission spectrum near 460 nm. The spatial maps of the temperature and the radical densities provide information on the chemical processes taking place in the discharge. The CH 3 and CH radical density measurements made in the dc discharge system are compared with similar measurements made in a hot filament CVD system. The [H]/[H 2 ] ratio is derived from the CH 3 and CH densities using an analysis based on partial thermodynamic equilibrium of the single carbon hydrocarbon abstraction reactions.