Microstructure and composition of MgF2 optical coatings grown on Si substrate by PVD and IBS processes

MgF2 is a current material for the optical applications in the UV and deep UV range. Nevertheless, modern applications still require improvement of th e optical and structural quality of the deposited layers. In the present wo rk, the composition and microstructure of MgF2 single layers grown on Si [1 00] substrate by physical vapour deposition (PVD) and ion beam sputtering ( IBS) processes, were analyzed and compared. Experiments were carried out us ing X-ray photoelectron spectroscopy (XPS) in depth profile, grazing angle X-ray diffraction (XRD) and transmission electron microscopy (TEM). Both la yers exhibited a good stoichiometry and a low level of contamination. The s ample grown by IBS revealed more homogeneous and regular columnar microstru cture than the other one. (C) 2000 Elsevier Science S.A. All rights reserve d.