Low defect density a-plane GaN films were successfully grown by sidewall epitaxial lateral overgrowth (SELO) technique. Control of V/III ratio during the growth of GaN by metalorganic vapor phase epitaxy (MOVPE) was found to be very important to achieve a complete overgrowth on the SiO{sub}2 mask regions and atomically flat surface. The threading dislocation and stacking fault densities in the overgrown regions were lower than 10{sup}6cm{sup}(-2) and 10{sup}3cm{sup}(-1), respectively. The root mean square roughness was 0.09nm. We also fabricated and characterized a-plane-GaN-based-light-emitting diodes (LEDs) using SELO technique. The light output power of the blue-green LED steeply increased with the decrease of threading dislocation density from 10{sup}10cm{sup}(-2) to 10{sup}8cm{sup}(-2) and tended to saturate at lower dislocation densities.
展开▼
