Published online by Cambridge University Press: 10 February 2011
Ruthenium oxide films were deposited on Al2O3 (0001) and (1102) substrates using reactive sputtering under two different target surface conditions. Films grown when the surface of the target was metallic ruthenium (metallic-target) showed a Ru: O ratio of 1: 2.0±0.05 as determined by Rutherford backscattering spectrometry. At elevated deposition temperatures, these films aligned with the substrates as RuO2 (100) ║ A12O3 (0001) and RuO2 (101) ║ Al2O3(1102). Films deposited when the target surface was fully oxidized (oxidized-target) exhibited a Ru: O ratio of 1: 2.5±0.05 and displayed an oriented crystalline structure even at room temperature. The resistivity of the RuO2.5 films was 75 μΩ-cm and was independent of temperature between 5 and 300 K. Possible causes of this behavior are discussed.