Interfacial structure of MBE grown InN on GaN

✍ Scribed by Kehagias, Th. ;Iliopoulos, E. ;Delimitis, A. ;Nouet, G. ;Dimakis, E. ;Georgakilas, A. ;Komninou, Ph.

• Book ID: 105363191
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 127 KB
• Volume: 202
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200461343

✦ Synopsis

Abstract

The structural properties of the interfacial area of InN thin films, grown by rf‐plasma MBE on top of GaN/Al~2~O~3~ substrates have been investigated by TEM and HRTEM. Continuous or columnar film growth highly depends on the pre‐growth of an InN nucleation layer and low substrate temperatures. The lattice constants in both growth cases were determined by electron diffraction analysis. A network of 60° misfit dislocations was introduced in the InN/GaN interface to accommodate the lattice mismatch between the two crystals. The degree of residual compressive strain in the continuous film is also calculated, considering the columnar film closer to the relaxed configuration. The good agreement between the experimental and the calculated value for the misfit dislocation spacing provides evidence that the residual compressive strain is minimized. The in‐plane lattice expansion, observed in the continuous InN film, is attributed to thermal tensile strain originating from the difference in the thermal expansion coefficients of InN and GaN. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)