Microstructural characterization of V-defects in InGaN/GaN multiquantum wells
H. Wang+, G. Jin+, Q. Tan+*
+Academy of Electronic Information and Electrical Engineering, Xiangnan University Chenzhou, 423000, China
*Institute of Physics and Information Science, Hunan Normal University, Changsha, 410081, China
Abstract
InGaN multiple-quantum-well (MQW) structures grown by metal-organic chemical-vapor deposition
(MOCVD) are found to contain V-defects attached to threading dislocations. The nature of the V-defects
was evaluated using transmission electron microscopy (TEM), atomic force microscope (AFM), secondary
ion mass spectroscopy (SIMS). Some (a+c) dislocations were shown to decompose inside the multi-quantum
well, giving rise to a misfit segment in the c-plane and a V-defect. The V-defects in the
multiple-quantum-well have the thin six-walled structure with InGaN/GaN layers. The
mechanism of formation of these defects has been discussed in terms of stress induced by lattice
mismatch and reduced In incorporation on the planes in comparison to the (0001) surface.