Dielectric properties of aluminum silver alloy thin films in optical frequency range

Abstract

The dielectric properties of direct current (dc) magnetron sputtering aluminum silver alloy films in optical frequency have been quantitatively studied by variable angle spectroscopic ellipsometry. The structure and surface topography of the alloy films were characterized using scanning probe microscopy and x-ray diffraction. The Drude–Lorentz model was used to simulate the dielectric function of Al-Ag alloy films. Meanwhile, the effective medium theory has been utilized for the treatment of surface roughness. We found that the interband transition around 1.5 eV can be shifted through a variable annealing temperature and a changeable silver percentage of Al-Ag alloys.