Growth of thick GaN layers with hydride vapour phase epitaxy
2005 (English)In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 281, no 1, 17-31 p.Article in journal (Refereed) Published
In this paper we describe recent experimental efforts to produce high quality thick (⩾300 μm) GaN layers on sapphire, the removal of such a layer from the sapphire substrate, and the properties of the so obtained free-standing GaN material. The growth process is described in some detail in the vertical reactor geometry used in this work. Defects like dislocations, micro-cracks and pits produced during growth are discussed, along with procedures to minimize their concentration on the growing surface. The laser lift-off technique is shown to be a feasible technology, in particular if a powerful laser with a large spot size can be used. A major problem with the free-standing material is the typically large bowing of such a wafer, due to the built in defect concentrations near the former GaN-sapphire interface. This bowing typically causes a rather large width of the XRD rocking curve of the free-standing material, while optical data confirm virtually strain free material of excellent quality at the top surface.
Place, publisher, year, edition, pages
2005. Vol. 281, no 1, 17-31 p.
characterization, computer simulation, defects, chloride vapour phase deposition, gallium nitride
National CategoryEngineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-46086DOI: 10.1016/j.jcrysgro.2005.03.040OAI: oai:DiVA.org:liu-46086DiVA: diva2:266982