Surfactant effects of indium on cracking in AlN/GaN distributed Bragg reflectors grown via metal organic vapor phase epitaxy

• Published in: Superlattices and microstructures Vol. 49; no. 1; pp. 52 - 59
• Main Authors: Rodak, L.E., Miller, C.M., Korakakis, D.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2011
• Subjects: Aluminum nitride; Cracks; Distributed Bragg reflectors; Fracture mechanics; Gallium nitrides; Indium; Metal organic vapor phase epitaxy; Nitrides; Surfactant; Surfactants; Thermal expansion; Vapor phase epitaxy; Metal organic vapor phase epitaxy; Nitrides; Distributed Bragg reflectors; Surfactant
• ISSN: 0749-6036; 1096-3677
• DOI: 10.1016/j.spmi.2010.11.001

Aluminum Nitride (AlN) and Gallium Nitride (GaN) superlattice structures are often characterized by a network of cracks resulting from the large lattice mismatch and difference in thermal expansion coefficients, especially as the thickness of the layers increases. This work investigates the influence of indium as a surfactant on strain and cracking in AlN/GaN DBRs grown via Metal Organic Vapor Phase Epitaxy (MOVPE). DBRs with peak reflectivities ranging from 465 nm to 540 nm were grown and indium was introduced during the growth of the AlN layer. Image processing techniques were used to quantify the crack length per square millimeter and it was observed that indium has a significant effect on the crack formation and reduced the total crack length in these structures by a factor of two. ► Investigated surfactant effects of indium on AlN/GaN distributed Bragg reflectors. ► Image processing techniques were employed to quantify the amount of cracking. ► Under optimal conditions, indium can be used to reduce the cracking by a factor of two.