Observation of dislocations and their arrays in physical vapor transport-grown AlN single-crystal substrate by synchrotron X-ray topography

Abstract

Dislocations in a single-crystal aluminum nitride bulk substrate have been characterized using synchrotron X-ray topography (XRT). Threading edge dislocations (TEDs) and screw-type dislocations as well as {0001}-plane basal plane dislocations have been observed, and their Burgers vectors were evaluated based on the XRT contrast of these dislocations. Particular attention has been paid to the direction of the Burgers vectors of dislocation arrays composed of TEDs. By analyzing the bright/dark contrast change of these TED arrays when all six different g-vectors (equivalent to g = 11-26) were applied, the directions of the a-axis components of Burgers vectors were determined.