Highly reflective GaN/Al[sub 0.34]Ga[sub 0.66]N quarter-wave reflectors grown by metal organic chemical vapor deposition.

Quarter-wave reflectors consisting of sets of GaN and Al[sub 0.34]Ga[sub 0.66]N layers have been grown on sapphire substrates by atmospheric-pressure metal organic chemical vapor deposition. A periodic structure with flat interfaces was observed by high-resolution scanning electron microscopy. X-ray diffraction measurements were performed to characterize the structures, from which the Al content x in the Al[sub x]Ga[sub 1-x]N layers was determined to be 0.34. No cracks could be seen on the surface of the reflectors by optical microscopy. The measured peak reflectivity at 390 nm increases with the number of pairs and reaches as high as 96±2% in the 35-pair reflector. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]