Structural analysis of In/Ag, In/Cu and In/Pd thin films on tungsten by ellipsometric, XRD and AES methods

Compositional, microstructural and optical properties of In/Cu, In/Ag and In/Pd thin films evaporated on W substrate in a vacuum were investigated by means of Auger electron spectroscopy, X-ray diffractometry, scanning electron microscopy, and spectroscopic ellipsometry methods. Thicknesses of deposited pure metal layers were adjusted to atomic concentration ratios In:Ag = 1:2, In:Cu = 2:1 and In:Pd = 3:1. Interdiffusion of metals and creation of intermetallic compounds AgIn2, Ag2In and CuIn2were detected at room temperature. Phase transformation and changes in the surface morphology due to annealing of samples at 393 K for 60 min were revealed. Combined investigations indicated a layered structure of In/Ag films. A tendency of island-like structure formation was stronger for In/Cu and In/Pd films. The complex dielectric functions 〈ϵ˜(E)〉=〈ϵ1(E)〉+i〈ϵ2(E)〉 of In/Ag, In/Cu and In/Pd composite layers were determined from spectroellipsometric data.