Temperature-gradient Organometallic Vapor Phase Epitaxy (OMVPE) was used to deposit InxGa1-xN/GaN MQW structures with a concentration gradient of In across the wafer. These MQW structures were deposited on low defect density (1.7x108 cm?²) GaN template layers for investigation of microstructural properties and V-defect formation. Room temperature (RT) photoluminescence (PL) and photomodulated transmission (PT) were used for optical characterization. Triple-axis X-ray diffraction (TAXRD) and cross-section transmission electron microscopy (XTEM) were used to obtain microstructural properties of different regions across the wafer. Results show that there is a decrease in crystal quality and an increase in V-defect formation with increasing indium concentration. The depth of extension of the V-defects also increases with decreasing growth temperature and increased indium concentration. A direct correlation is found between V-defect density and growth temperature due to increased strain for increasing indium concentration.
Revised: October 25, 2005 |
Published: May 1, 2005
Citation
Johnson M.C., Z. Liliental-Weber, D.N. Zakharov, D.E. McCready, R.J. Jorgensen, J. Wu, and W. Shan, et al. 2005.Investigation of Microstructure and V-defect Formation in InxGa1-xN/GaN MQW Grown using Temperature-Gradient Metalorganic Chemical Vapor Deposition.Journal of Electronic Materials 34, no. 5:605-611.PNNL-SA-42438.