Polar and nonpolar GaN grown by HVPE: Preferable substrates for nitride-based emitting devices
2004 (English)In: Physica status solidi. A, Applied research, ISSN 0031-8965, Vol. 201, no 10, 2265-2270 p.Article in journal (Refereed) Published
We report on hydride vapor phase epitaxial growth of thick nonpolar GaN films on r-plane sapphire in comparison with polar GaN films on c-plane sapphire substrates with AlN buffer layers, aiming at developing of their quasi-substrate application. Both the thick films and the buffers were identified to have single crystalline structures. The microstructure of the films was studied by transmission electron microscopy. High resolution X-ray diffraction mapping and photoluminescence measurements were employed to characterize the strain present in both polar and nonpolar GaN films. In contrast to c-plane GaN, which is always characterised by isotropic in-plane properties, the a-plane GaN shows a strong in-plane anisotropy of the growth rate, morphology and strain distribution. Different defect, impurity and free carrier concentrations were observed in the polar and nonpolar material.
Place, publisher, year, edition, pages
2004. Vol. 201, no 10, 2265-2270 p.
National CategoryEngineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-46187DOI: 10.1002/pssa.200404818OAI: oai:DiVA.org:liu-46187DiVA: diva2:267083