Original Publication Date
Applied Physics Letters
DOI of Original Publication
Date of Submission
Pendeoepitaxy on patterned templates has been proven to be efficient for reducing threading dislocation densities in GaN thin films. In this letter, we report on in situ crack-assisted pendeoepitaxy of GaN using spontaneously formed cracks in AlGaN∕GaNheterostructures. Our approach involves the growth of an AlGaN∕GaNtemplate followed by in situ thermal etching and deposition of an amorphous silicon nitride mask in a low pressure metal organic chemical vapor deposition system. Microwirelike GaN seeds are then formed along the crack lines during the initial stage of GaN overgrowth, which act as nucleation stripes for epitaxial lateral overgrowth. Transmission electron microscopy revealed that the lateral overgrowth of the wirelike GaN seeds effectively bends threading dislocations toward ⟨11¯00⟩ directions on the amorphous silicon nitride mask. The threading dislocation density by this method has been reduced from 2×109cm−2 in control samples to 2×108cm−2 in some parts and 5×107cm−2 in other parts of the GaN layer as determined by plan-view transmission electron microscopy which is very encouraging.
Moon, Y.T., Liu, C., Xie, J., et al. In situ pendeoepitaxy of GaN using heteroepitaxial AlGaN∕GaN cracks. Applied Physics Letters, 89, 024103 (2006). Copyright © 2006 AIP Publishing LLC.
Is Part Of
VCU Electrical and Computer Engineering Publications