Deposition pressure effect on chemical, morphological and optical properties of binary Al-nitrides

• Deposition pressure effect on chemical, morphological and optical properties.
• Dependence of optical constant as function of deposition parameter in AlN films.
• Purity color dependence in AlN films demonstrates the possibility of purity color control.

Aluminum nitride films (AlN) were produced by Nd:YAG pulsed laser (PLD), with repetition rate of 10 Hz. The laser interaction on Al target under nitrogen gas atmosphere generates plasma which is produced at room temperature with variation in the pressure work from 0.39 Pa to 1.5 Pa thus producing different AlN films. In this sense the dependency of optical properties with the pressure of deposition was studied. The plasma generated at different pressures was characterized by optical emission spectroscopy (OES). Additionally ionic and atomic species from the emission spectra obtained were observed. The plume electronic temperature has been determined by assuming a local thermodynamic equilibrium of the emitting species. Finally the electronic temperature was calculated with Boltzmann plot from relative intensities of spectral lines. The morphology and composition of the films were studied using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy analysis (XPS) and Raman Spectroscopy. The optical reflectance spectra and color coordinates of the films were obtained by optical spectral reflectometry technique in the range from 400 nm to 900 nm. A clear dependence in morphological properties and optical properties, as a function of the applied deposition pressure, was found in this work which offers a novel application in optoelectronic industry.