Structural characterization of thick (1122) GaN layers grown by HVPE on m-plane sapphire

• Published in: Physica status solidi. A, Applications and materials science Vol. 207; no. 6; pp. 1295 - 1298
• Main Authors: Usikov, Alexander, Soukhoveev, Vitali, Shapovalov, Lisa, Syrkin, Alexander, Ivantsov, Vladimir, Scanlan, Bernard, Nikiforov, Alexey, Strittmatter, Andre, Johnson, Noble, Zheng, Jian-Guo, Spiberg, Philippe, El-Ghoroury, Hussein
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.06.2010; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: cathodoluminescence; Condensed matter: structure, mechanical and thermal properties; Defects and impurities in crystals; microstructure; dislocations; Exact sciences and technology; Experimental determination of defects by diffraction and scattering; GaN; HVPE; laser; Physics; quantum wells; structure; Structure of solids and liquids; crystallography; Dislocation density; Thickness; Template method; Transmission electron microscopy; Threading dislocation; Thick films; Stacking fault density; VPE; XRD; Cathodoluminescence; Gallium nitride
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.200983655

This paper reports structural characterization of thick $(11\bar {2}2)$‐oriented GaN layers by means of XRD, TEM, and micro‐ CL. The semi‐polar $(11\bar {2}2)$ GaN layers were grown on m‐plane sapphire substrates by HVPE. Their structural quality improved with thickness. Threading dislocation density of 3 × 108 cm−2 and stacking faults density of 4 × 104 cm−1 were measured at the surface of 20 µm thick $(11\bar {2}2)$ GaN layers. The semi‐polar GaN layers were used as template substrates to grow InGaN/GaN MQW heterostructures by MOCVD that demonstrated optically pumped lasing at 500 nm wavelength. The results demonstrate the longest wavelength yet reported for a photo‐pumped laser on template substrates.