Ab. Harker et al., DIRECT OBSERVATION OF THE DEFECT STRUCTURE OF POLYCRYSTALLINE DIAMONDBY SCANNING ELECTRON-MICROSCOPY, Applied physics letters, 62(24), 1993, pp. 3105-3107
A method has been demonstrated to directly observe the surface crystal
lography and defect structures in diamond films by scanning electron m
icroscopy. Individual diamond crystals in the polycrystalline films ar
e polished to a rms smoothness of less than 2 nm using iron metal at t
emperatures in excess of 725-degrees-C. In the absence of topography,
the detailed microstructure of the films can be characterized by secon
dary electron imaging in a scanning electron microscope by charge-indu
ced electron contrast which shows strong beam voltage dependence. It i
s hypothesized that defects and grain boundaries form a connected path
way in the film which has greater conductivity than the generally insu
lating diamond and creates the charge-induced contrast.