ELECTRICAL-RESISTIVITY OF RUOX THIN-FILMS PREPARED BY ION-BEAM SPUTTER DEPOSITION

A compact ion source using a hollow cathode discharge was fabricated and was applied to the ion beam sputter deposition of RuOx thin films. Ar or Ar + 02 mixture was employed as the working gas and a compressed RuO2 powder disk was used as the target. Sputter deposition was carried out by varying the acceleration voltage in the range of 1-5 kV. Electron energy loss spectroscopy (EELs) analysis indicated that the RuO2 was reduced into RuOx through the sputtering process. The electrical resistivity of RuOx films, about 100 nm thick, is higher than the bulk value of RuO2 (3.5 x 10(-5) OMEGA . cm) by about two orders of magnitude. This may be attributed to the amorphous structure of the RuOx films and to the incorporation of foreign atoms. The incorporation of Fe from the ion source into the RuOx films was confirmed by EELS analysis. Temperature dependence of the resistivity of RuOx films prepared at different acceleration voltages was also examined.