Synthesis of aluminium nitride thin films by ion-vapour deposition method

Abstract

Aluminium nitride (AlN) thin films have been synthesized by evaporation of aluminium and simultaneous irradiation with nitrogen ions (ion-vapour deposition method). The substrate temperature has been kept at room temperature or 473 K and the kinetic energy of the incident nitrogen ion beam has been varied from 0.5 to 2.0 keV. The microstructure of the synthesized films has been examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). In the XRD patterns of films synthesized at both room temperature and 473 K the diffraction line indicating the AlN (100) plane can be discerned and the broad peak composed of two lines indicating the AlN(002) and AlN(101) planes is also observed. TEM observations reveal that the films synthesized at 473 K show a more highly crystallized structure rather than the films synthesized at room temperature. The intensity of the AlN(002) and AlN(101) planes is found to increase with decreasing nitrogen ion energy at the substrate temperature of 473 K. The present results suggest that the synthesis of c-axis-oriented AlN films is feasible by controlling the substrate temperature and the incident ion energy.