Structural analysis of dislocations in type-IIa single-crystal diamond

High-quality crystals with flat surfaces and low defect densities are required in order to realize stable high performance in diamond-based power devices. Type-IIa single-crystal diamond that has no inclusions is thought to have potential as a defectless substrate. However, with today's crystal growth methods, there exist many dislocations in the type-IIa diamond, and thus this potential remains unrealized. In this paper, we describe the identification of dislocations in type-IIa diamond using X-ray topography. From the quantitative dislocation density analysis, it is estimated that the half of the dislocations are 45° dislocations and one-fourth of the dislocations are edge dislocations and 60° dislocations.

► Analyzed dislocations are in high-quality type-IIa single crystal diamond. ► There is a lot of dislocation, edge dislocation and mixed dislocation. ► When the density of dislocation is calculated by its type, mixed dislocation (45°) is about half of all dislocations.