The Preparation of Amorphous SixGeyOz Alloy Films by Sputtering. Preparation Conditions, Chemical Composition, and Vibrational Properties

Amorphous SixGeyOz, alloy films with x = 0.17 to 0.60, y = 0.19 to 0.68, and z = 0.11 to 0.42 are deposited using reactive dc magnetron sputtering in an Ar/water atmosphere. The alloy concentrations are measured by secondary neutral mass spectrometry (SNMS). The oxygen content strongly decreases with decreasing silicon concentration. The dependence of the alloy composition on the target coverage with germanium pieces is investigated. IR transmission measurements in the range from 400 to 4000 cm−1 show a predominance of the SiOSi asymmetric stretching mode. The minor absorption band due to GeOGe stretching vibrations totally disappears after annealing the film at 800 °C. An increase of the SiOSi absorption mode is detected.