Investigation of d.c.-reactive magnetron-sputtered AlN thin films by electron microprobe analysis, X-ray photoelectron spectroscopy and polarised infra-red reflection

Abstract

Thin films of AlN were deposited at a total gas pressure of 7×10 −4 mbar and a nitrogen partial presure of 9×10 −5 mbar by reactive d.c. magnetron sputtering. Low-carbon steel 08KP, Si (100) wafers and monocrystal KCl were used as substrates. Electron microprobe analysis (EMA), X-ray photoelectron spectroscopy (XPS), polarised infra-red reflection and infra-red (PIRR) transmission measurements were carried out to characterise these films. The EMA analysis confirms the microcrystalline structure of our films. From an XPS spectrum of the deposited AlN films, we have demonstrated that AlN was formed at these values of total and partial pressures. The PIRR measurements indicate the presence of a phonon at about 680 cm −1, typical for AlN. The deposited films have a high transmittance (about 80%) in the wavelength region between 2.5 and 12 μm.