On angle resolved RF magnetron sputtering of Ge-Sb-Te thin films

Thin amorphous films of Ge-Sb-Te were deposited from Ge2Sb2Te5 target by RF (f = 13.56 MHz) magnetron sputtering in argon plasma. Composition and chemical homogeneity of target and prepared thin films were traced by Energy Dispersive X-ray Analysis coupled with Scanning Electron Microscope (SEM-EDX). SEM technique was also used for surface morphology observation. Crystallinity of target and prepared thin films was studied by X-ray Diffraction (XRD). Optical parameters of prepared thin films (spectral dependence of refractive index, optical band gap energy Egopt) and film thicknesses were established via Variable Angle Spectroscopic Ellipsometry (VASE) supported by UV-Vis-NIR spectroscopy. Influence of deposition conditions (RF power, Ar pressure, angle divergency from normal direction) to composition, crystallinity, optical properties and deposition rate was established.