Influence of substrate temperature and ion-beam energy on the syntheses of aluminium nitride thin films by nitrogen-ion-assisted pulsed-laser deposition

Abstract

Aluminium nitride (AlN) thin films have been grown on Si(100), Si(111) and Sapphire Al2O3(001) substrates by pulsed KrF excimer laser (wavelength 248 nm, duration 30 ns) ablation of an AlN target with the assistance of nitrogen-ion-beam bombardment. The influence of process parameters such as substrate temperature and ion-beam energy has been investigated in order to obtain high-quality AlN films. The AlN films deposited by pulsed-laser deposition (PLD) have been characterized by X-ray diffraction (XRD) to determine the crystalline quality, grain size and growth orientation with respect to the substrate. The XRD spectra of AlN films on Si(100), Si(111) and Sapphire substrates yield full-width-half-maximum (FWHM) values of approximately 2.3-1.6°. The bonding characteristics in the films have been evaluated by Raman spectroscopy. The chemical composition of the films has been characterized by X-ray photoelectron spectroscopy (XPS). The surface morphology of the films has been measured by atomic force microscopy (AFM). At a substrate temperature of at least 600°C, polycrystalline AlN films with orientations of AlN(100) and AlN(101) have been synthesized.