Jb. Cui et al., SPECIES CHARACTERIZATION FOR A DIRECT-CURRENT-BIASED HOT-FILAMENT GROWTH OF DIAMOND USING SPATIAL RESOLVED OPTICAL-EMISSION SPECTROSCOPY, Applied physics letters, 69(21), 1996, pp. 3170-3172
Spatial resolved optical emission spectroscopy was applied for a direc
t-current biased hot filament diamond growth system with a spatial res
olution of better than 1 mm. Emission lines from atomic hydrogen, CH,
CH+, H-2, and Ar were observed in the visible region. It is found that
emission intensity of all the observed lines decreases rapidly as the
probe distance from the filament center raises. and increases near th
e substrate surface. The relative concentration of atomic hydrogen has
been estimated by using the emission line of Ar at 750.4 nm as an act
inometer. The concentration of atomic hydrogen decreases from filament
to the substrate and drops sharply at the substrate surface. The emis
sion spectra and the distribution of hydrogen atom along the substrate
surface have also been measured, which are closely correlated with th
e homogeneity of diamond film growth. And the low concentration of ato
mic hydrogen at the edge of the substrate results in a worsening of di
amond films. (C) 1996 American Institute of Physics.