Growth Characteristics and Properties of RuAlO Hybrid Films Fabricated by Atomic Layer Deposition

In this work, RuAlO hybrid films were synthesized by alternating ALD sequences of Al2O3 and Ru for electrical conductivity regulation. O-2 exposure has significant effects on the nucleation and etching processes of Ru, therefore the O-2 exposure was first optimized for efficient growth of Ru. A set of RuAlO hybrid films with different Ru subcycle ratios were fabricated. In-situ quartz crystal microbalance (QCM) measurement revealed a certain nucleation delay when Ru was deposited on the surface of Al2O3, while no nucleation delay was observed when Al2O3 was deposited on Ru. High resolution transmission electron microscopy (HRTEM) char-acterization confirmed formation of Ru grains embedded in amorphous Al2O3 matrix. Elemental mapping results demonstrated that Ru and Al elements are uniformly distributed on the cross section of the film. In the grazing incidence angle X-ray diffraction (GIAXRD) patterns of RuAlO hybrid films, characteristic diffraction peaks of Ru appear with a Ru subcycle ratio >= 70 %. By properly tuning the Ru to Al2O3 ALD subcycle ratio, electrical re-sistivity of the RuAlO hybrid film could be adjusted over a wide range of 10(-3) similar to 10(11) Omega.cm.