6533b7d1fe1ef96bd125d6e6

RESEARCH PRODUCT

Flash annealing influence on structural and electrical properties of TiO2/TiO/Ti periodic multilayers

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Abstract Multilayered structures with a 40 nm period composed of titanium and two different titanium oxides, TiO and TiO 2 , were accurately produced by DC magnetron sputtering using the reactive gas pulsing process. These multilayers were sputtered onto Al 2 O 3 sapphire to avoid substrate compound diffusion during flash annealing (ranging from 350 °C to 550 °C). Structure and composition of these periodic TiO 2 /TiO/Ti stacks were investigated by X-ray diffraction, X-ray photoemission spectroscopy and transmission electronic microscopy techniques. Two crystalline phases α-Ti and fcc-TiO were identified in the metallic-rich sub-layers whereas the oxygen-rich ones were composed of a mixture of amorphous and rutile TiO 2 phase. DC electrical resistivity ρ measured for temperatures ranging from 25 to 200 °C was influenced by the thermal treatments. The temperature coefficients of resistance of these periodic TiO 2 /TiO/Ti multilayers were modified from 11.7 × 10 − 04 to − 8.81 × 10 − 04  K − 1 . Local changes of crystallinity were reported and the resistivity responses of these annealed films could be linked to the typical electrical behavior of a metal–oxide mixture.