Configuration of a single grown-in dislocation corresponding to one etch pit formed on the surface of CVD homoepitaxial diamond

We present a detailed crystalline structure around one etch pit formed on the as-grown surface of a (001)-oriented chemical vapor deposition (CVD) homoepitaxial single crystal diamond film investigated using cross-sectional transmission electron microscopy (TEM). One threading dislocation corresponding to one pit is found, and it is shown that this dislocation line continuously runs from the apex of the pit to the deeper region in the film toward the substrate. The observed threading dislocation directs parallel to the approximate [001] film-growth direction, but is not a perfect straight line and propagates in a zig-zag manner. The contrast analysis of the dislocation in TEM micrographs is performed under several major two-beam reflections. These results suggest that the dislocation is composed of short segments of undissociated perfect dislocations with Burgers vectors b=1/2[110], 1/2[011] and 1/2[101] lying on the {111} glide plane and, as a whole, travels approximately parallel to the [001] direction.