Oxygen incorporation in Mo/Ni multilayers

• Published in: Thin solid films 1992-09, Vol.216 (2), p.259-267
• Main Authors: Makous, John L, Lareau, Richard T, Hues, Steven M
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Metals. Metallurgy; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/0040-6090(92)90847-5

We describe the effects of oxygen incorporation on the structural and elastic properties of Mo/Ni multilayers. Auger depth profiling analyses of the multilayers show that the oxygen level in the nickel layers saturates at 7 at.% while that in the molybdenum layers steadily increases as the average oxygen incorporation in the multilayers is increased to 20 at.%. X-ray diffraction measurements indicate that a structural transition from coherent superlattices to incoherent multilayers occurs at an average bilayer oxygen concentration of about 10–12 at.%. At oxygen concentrations above this level the structural analyses of the individual molybdenum and nickel layers indicate a continuous breakdown in the ordering of the molybdenum layers concurrent with an improvement in the structural order in the nickel. Surface acoustic wave velocity measurements demonstrate an elastic hardening with increasing oxygen incorporation that is consistent with the observed relaxation in the nickel layers and with previous work on the elastic properties of Mo/Ni multilayers.