Cathodoluminescence (CI), Raman spectroscopy and transmission electron
microscopy (TEM) have been used to study chemical vapour deposited (C
VD) diamond films. Most of this work was carried out on flame-grown CV
D diamond film on a silicon substrate. CL was used to identify and map
the distribution of defects in films. The CL spectra from cubo-octahe
dral crystallites of the flame-grown sample showed nitrogen-related 53
3 nm (2.326 eV) and 575 mn (2.156 eV) systems. The zero-phonon lines w
ere found to be split into two or three components, and by correlation
with Raman spectroscopy results the splitting was attributed to a sur
face tensile stress. A stress variation across crystallites was studie
d by imaging in each of these components. Below the surface of the cry
stallite high compressive stresses were detected by Raman spectroscopy
. Another sample, grown by hot filament chemical vapour deposition, wa
s studied mainly by TEM in order to elucidate the microstructure of th
ese films. High densities of twins, stacking faults and dislocations w
ere found to be correlated with particular regions of the deposit and
to vary in a systematic fashion with distance from the substrate inter
face. An attempt has been made to present a consistent picture of stre
ss in the cube-octahedral crystals of these samples by relating the re
sults acquired from the different techniques used in this work.