XRD and RBS studies of quasi-amorphous zinc oxide layers produced by Atomic Layer Deposition

Although zinc oxide has been widely investigated for many important applications such as laser diodes, photovoltaics, and sensors, some basic properties of this material have not been established up to now. One of these are stopping power values which are crucial for the Rutherford Backscattering Spectrometry analysis. For this kind of measurements, amorphous materials should be used. In this paper we show the results of stopping power measurements for ZnO films grown by Atomic Layer Deposition. The films were grown on a silicon (100) substrate and parameters of the growth were chosen in a way that prevents crystallization of ZnO films. A series of ZnO films with thickness between 20 and 160 nm have been investigated. Extended film characterization has proven that the obtained nanopolycrystalline ZnO films can be considered as truly amorphous with respect to ion beam applications. ZnO films have been used for precise stopping power measurement of MeV He-ions in the energy range from 200 to 5000 keV. These results provide indispensable data for ion beam modification and analysis of ZnO.