Corekci, S.Ozturk, M. K.Cakmak, M.Ozcelik, S.Özbay, Ekmel2015-07-282015-07-2820121369-8001http://hdl.handle.net/11693/13206Undoped AlN layers have been grown on c-plane sapphire substrates by metal-organic chemical vapor deposition in order to study the effects of ammonia (NH3) flow rate and layer thickness on the structural quality and surface morphology of AlN layers by high-resolution X-ray diffraction, scanning electron microscopy, and atomic force microscopy. Lower NH3 flow rate improves crystallinity of the symmetric (0 0 0 2) plane in AlN layers. Ammonia flow rate is also correlated with surface quality; pit-free and smooth AlN surfaces have been obtained at a flow rate of 70 standard cm(3) per minute. Thicker AlN films improve the crystallinity of the asymmetric (1 0 1 (1) over bar 2) plane.EnglishALN thin filmsAmmonia flow rateArticle10.1016/j.mssp.2011.06.003