Characterization of dislocation arrays in AlN single crystals grown by PVT

Abstract

AbstractThe density and distribution of extended defects in AlN single crystals grown by physical vapor transport (PVT) was studied by bright field and polarized light microscopy, defect‐selective etching, and high resolution X‐ray diffraction (HRXRD). Etch pits associated with dislocation arrays forming low angle grain boundaries (LAGB) were observed and two types of LAGB were identified. Reduction of LAGB in AlN grown under reduced radial temperature gradients, as estimated by simulation of the growth cell, was demonstrated.