Optical properties of ion implanted AIN x

Abstract

The effect of ion implantation on optical properties of AlN x films has been investigated by measuring transmittance of visible radiation. Two kinds of AlN x films with x = 0.83 and x = 1.43, respectively, were prepared on the surface of microscope plate glasses and silicon wafers by using an activated reactive evaporation (ARE) method. Ion implantation into the thin films of AlN x was carried out with a dose range from 5 × 10 16 to 5 × 10 17 N +/cm 2 at energies of 40 and 80 keV. After nitrogen ion implantation, the transmittance of Al rich films deposited on glass increased from less than 10% of virgin state to above 70% with increasing doses. It also increased with decreasing acceleration energies. In the case of N rich films, relatively low dose implantation was found to be sufficient to improve the transmittance from 60% to 85%. The improvement of the transmittance is considered as the result of AlN formation, which was confirmed by the 670 cm −1 IR peak in the FTIR spectra for the films deposited on silicon substrates with the same implantation condition. It is found that ion implantation is effective in improving the visible transmittance of AlN x thin films. At higher energy, the mechanism for the improvement is energy deposition whereas at lower energy the nitrogen doping effect may also be significant.