Monocrystalline CVD synthetic diamond samples grown onto (001) substrates were studied using X-ray topography, photoluminescence imaging, cathodoluminescence imaging and transmission electron microscopy. X-ray section topographs sampling a plane very close to the surface of a (010) cross-sectional slice showed contrast that was closely correlated with photoluminescence image contrast relating to differences in incorporation of point defects on step risers and terraces during growth. The point defect content was too low to influence X-ray topography contrast and therefore the correlation suggested a difference between the dislocation content for terrace and riser growth. Dislocations imaged in cathodoluminescence were observed to follow paths that were strongly influenced by step flow during growth. Transmission electron micrographs showed [001] dislocations with sections of <110> 60° or edge dislocations in configurations consistent with formation as a result of step flow growth. It was proposed that a passing riser can cause dislocations to switch from [001] to [101] line direction when this minimises the increase in the energy associated with the dislocation as riser growth proceeds.

Effect of Steps on Dislocations in CVD Diamond Grown on {001} Substrates. P.Martineau, M.Gaukroger, R.Khan, D.Evans: Physica Status Solidi C, 2009, 6[8], 1953-7