Deposition of thin films by ion beam sputtering: Mechanisms and epitaxial growth

In this paper, the capabilities of ion beam sputtering (IBS) to prepare epitaxial layers of various materials are investigated. Thin films (W<0.5 μm) of silicon, yttria stabilized zirconia (YSZ), tungsten and nickel were deposited using an UHV apparatus equipped with surface analytical tools (RHEED, Auger electron spectrometer). Rare gas ions (Ar, Kr, Xe) of 20 keV energy were used. Silicon homoepitaxial films deposited at temperature above 700°C showed structure and electrical properties close to the bulk. Layers of YSZ on Si substrates were deposited by sputtering of a (Y₂ O₃)_0.23 (ZrO₂)_0.77 target. Films of good epitaxial quality were grown on Si(100) substrates under partial pressure of oxygen at temperatures in the range 700°C–800°C. Tungsten silicide and Ni_xGaAs films were prepared by pure metal deposition on heated silicon and GaAs substrates, respectively. Structure and electrical properties of these films have been determined as a function of the deposition temperature. In order to improve the thin film properties, sputtering‐related phenomena were studied.