Study of dislocations in AlN single-crystal using bright-field synchrotron x-ray topography under a multiple-beam diffraction condition

Abstract

Dislocations in an AlN single crystal were studied via bright-field synchrotron x-ray topography under a multiple-beam diffraction (MBD) condition. Two-beam approximation conditions using nine different types of diffraction vectors (g) were applied, including five types near the MBD condition, and the Burgers vector (b) of dislocations was identified using the g·b invisibility criterion. Based on the assignment of the Burgers vectors, some of the propagation behaviors of the dislocation were observed, including dislocation reduction via a reaction between threading edge-type dislocations and the generation of a pair of dislocations that have opposite Burgers vectors.