Eur. Phys. J. D 64, 427-435 (2011)
https://doi.org/10.1140/epjd/e2011-20393-7

Regular Article

Growth and properties of Ti-Cu films with respect to plasma parameters in dual-magnetron sputtering discharges

¹ Ernst-Moritz-Arndt-Universität Greifswald, Institut für Physik, Felix-Hausdorff-Str. 6, 17489 Greifswald, Germany
² Institute of Physics v. v. i., Academy of Science of the Czech Republic, Na Slovance 2, 182 21 Prague, Czech Republic
³ Charles University in Prague, Faculty of Mathematics and Physics, V Holešovičkách 2, 180 00 Prague, Czech Republic

^a e-mail: stranak@physik.uni-greifswald.de

Received: 4 July 2011
Received in final form: 5 August 2011
Published online: 11 October 2011

Abstract

Properties of different methods of magnetron sputtering (dc-MS, dual-MS and dual-HiPIMS) are studied and compared with respect to intermetallic Ti-Cu film formation. The quality and features of thin films are strongly influenced by the energy of incoming particles. The ion velocity distribution functions (IVDFs) were measured by time-resolved retarding field analyzer (RFA) in the substrate position. Thin films were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD) and X-ray reflectometry (XR). Properties and crystallography of Ti-Cu films are discussed as a function of ion energy which is affected by the mode of sputtering. It was found that IVDFs measured in pulsed discharges exhibit double-peak distribution. The IVDFs reach the maximum at ion energies about  ~8 eV. The ion saturated current is highest in dual-HiPIMS discharge (~5 μA/cm²) and is mostly represented by Cu⁺ and Ar⁺ ions. The mode of sputtering influences chemical composition and film formation. The copper forms polycrystalline fcc-phase while much smaller Ti particles enwraps the copper crystallites or are part of a solid solution.