Reduction of Dislocations in Single Crystal Diamond by Lateral Growth over a Macroscopic Hole.

A low-dislocation diamond is obtained by homoepitaxial chemical vapor deposition on a standard moderate-quality substrate hollowed out by a large square hole. Dislocations are found to propagate vertically and horizontally from the substrate and to terminate at the top surface or at the sides of the hole, thus leaving the central part with a strongly reduced dislocation density.