Applied Surface Science, Vol.455, 919-923, 2018
Influence of temperature and A1/N ratio on structural, chemical & electronic properties of epitaxial A1N films grown via PAMBE
The present article investigates structural, chemical and electronic properties of epitaxial AlN films grown via plasma assisted molecular beam epitaxy on atomically clean Si (1 1 1) substrates. An inclusive optimization process of growth parameters by varying the substrate temperature (790-825 degrees C) and Al/N (III/V) ratio is demonstrated. The AlN film grown with optimized parameters yielded an FWHM of 24.6 arcmin, crystallite size of 11.6 nm, screw dislocation density of 4.43 x 10(9)/cm(2) and a surface roughness of 3.11 nm. Besides, the chemical states and electronic structure analysis displayed absence of remnant metallic aluminium and native surface oxide (-2%) with Fermi level (3.0 eV) pinned near its intrinsic value. A growth mechanism has been proposed for the optimized growth of AlN. Further, the high quality AlN film can potentially be used for the fabrication of smart optoelectronics for deep UV application and field emission devices.