In-plane epitaxial relationships between a-plane sapphire substrates and GaN layers grown by different techniques
2003 (English)In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 257, no 1-2, 1-6 p.Article in journal (Refereed) Published
We have studied GaN films grown on a-plane sapphire substrate by both hydride vapour phase epitaxy (HVPE) and metalorganic vapour phase epitaxy (MOVPE) using X-ray diffraction and transmission electron microscopy. The in-plane orientation relationships between the epitaxial films and the substrate are determined to be [1 1 2¯ 0]GaN?[0 0 0 1] sapphire and [1 1¯ 0 0]GaN?[1 1¯ 0 0] sapphire in the HVPE growth, while [1 1¯ 0 0] GaN?[0 0 0 1]sapphire and [1 1 2¯ 0] GaN?[1 1¯ 0 0]sapphire are found in the MOVPE growth. In a few films of both types a simultaneous presence of two domains, representing the two in-plane relationships, is observed although the preferable one in each type of films is strongly dominating. We propose that the two in-plane orientations of GaN are generally possible on the a-sapphire substrate and are related to the atom termination of the sapphire surface determined by the substrate pre-treatment used in the different growth methods. © 2003 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
2003. Vol. 257, no 1-2, 1-6 p.
A1. Epitaxial relationships, B1. A-plane sapphire, B1. GaN
National CategoryEngineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-46511DOI: 10.1016/S0022-0248(03)01374-5OAI: oai:DiVA.org:liu-46511DiVA: diva2:267407