The influence of thickness and ammonia flow rate on the properties of AlN layers


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Corekci S., Ozturk M. K. , Çakmak M. , Ozcelik S. , Ozbay E.

Materials Science in Semiconductor Processing, vol.15, pp.32-36, 2012 (Journal Indexed in SCI Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 15
  • Publication Date: 2012
  • Doi Number: 10.1016/j.mssp.2011.06.003
  • Title of Journal : Materials Science in Semiconductor Processing
  • Page Numbers: pp.32-36
  • Keywords: AlN thin films, Ammonia flow rate, GROWTH MODE MODIFICATION, X-RAY-DIFFRACTION, ALN/SAPPHIRE TEMPLATES, DISLOCATION DENSITIES, SAPPHIRE SUBSTRATE, OPTICAL-PROPERTIES, EPITAXY, QUALITY, MOVPE, MICROSTRUCTURE

Abstract

Undoped AlN layers have been grown on c-plane sapphire substrates by metal-organic chemical vapor deposition in order to study the effects of ammonia (NH 3) 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 NH 3 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 2) plane. © 2011 Elsevier Ltd. All rights reserved.