InGaN lattice constant engineering via growth on (In,Ga)N GaN nanostripe arrays

• Published in: Semiconductor science and technology Vol. 30; no. 10; pp. 105020 - 105028
• Main Authors: Keller, Stacia, Lund, Cory, Whyland, Tyler, Hu, Yanling, Neufeld, Carl, Chan, Silvia, Wienecke, Steven, Wu, Feng, Nakamura, Shuji, Speck, James S, DenBaars, Steven P, Mishra, Umesh K
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.10.2015
• Subjects: defects; gratings; indium gallium nitride; luminescence; nanostructures; strain
• ISSN: 0268-1242; 1361-6641
• DOI: 10.1088/0268-1242/30/10/105020

Planar (In,Ga)N layers were grown on nanostripe arrays composed of InGaN GaN multi quantum wells (MQWs) by metal-organic chemical vapor deposition. The MQW nanostripe arrays with height to width aspect ratios of about 0.5 and 1 were fabricated from planar coherently strained InGaN GaN MQW samples. Independent of their aspect ratio, the nanostripes exhibited elastic relaxation perpendicular to the stripe direction after pattern fabrication, resulting in an a lattice constant perpendicular to the stripe direction larger than that of the GaN base layer. In a subsequent step, (In,Ga)N layers were grown on top of the nanostripe arrays, leading to the formation of planar films with a similar a lattice constant as the MQW stripes beneath. Bright luminescence was recorded from the planar, partially relaxed re-grown (In,Ga)N layers grown on the stripe arrays with an aspect ratio of 1. Plastic relaxation of the MQW stripes was observed after (In,Ga)N regrowth for samples with a stripe aspect ratio of 0.5, leading to luminescence quenching.