PEMBE-Growth of Gallium Nitride on (0001) Sapphire: A comparison to MOCVD
grown GaN
H. Angerer, O. Ambacher, R. Dimitrov, Th. Metzger, W. Rieger, M. Stutzmann
Walter Schottky Institut, Technische Universität München
This article was received on June 2, 1996 and
accepted on October 8, 1996. Abstract
Thin films of GaN on c-plane sapphire were grown by plasma-enhanced
molecular beam epitaxy (PEMBE). The influence of different growth conditions on
the quality of the epitaxial layers was studied by x-ray diffraction (XRD),
atomic force microscopy (AFM) and Hall measurements. For low deposition
temperatures, the growth of a thin buffer layer of AlN results in a decrease of
the XRD rocking curve full width at half maximum (FWHM) but also in poorer
quality in electronic and optical properties. Samples of 3µm thickness with
570 arcsec FWHM in the XRD rocking curve, a near band gap PL-emission FWHM at
5 K of 7 meV, charge carrier densities of n
