AVS 45th International Symposium
    Vacuum Metallurgy Division Monday Sessions
       Session VM-MoP

Paper VM-MoP2
Deposition of bcc Ta and beta-Ta Films using Different Underlayers

Monday, November 2, 1998, 5:30 pm, Room Hall A

Session: Vacuum Metallurgy Division Poster Session
Presenter: L.V. Kozlovsky, University of Daugavpils, Latvia
Authors: L.V. Kozlovsky, University of Daugavpils, Latvia
A. Antinsh, University of Daugavpils, Latvia
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The formation of crystalline phases in sputtered Ta films can be attributed to the deposition conditions as well as to the nature of the substrate. We deposited 100 nm Me / X nm Ta (Me: Mo, W, Nb, Ti, Zr, Hf, Dy, Fe, Al; X = 40,100, 200 nm) bilayers on room-temperature glass substrates in a Xe discharge at a pressure of (5 - 8) x10@super -4@ Torr using Penning discharge sputtering devices @footnote 1@. The base pressure was nearly 5x10@super -9@ Torr. 10 nm C underlayers were deposited on substrates at the same vacuum conditions before bilayers deposition. The structure of the films was investigated by X-ray diffraction (XRD). XRD profiles revealed peaks corresponding to (110), (220), (211) reflections of bcc Ta, peaks at d = (0.2665 0.2672) nm and the second orders of these reflections. The peaks were attributed to the beta-Ta phase in the films. Ta films on Nb, W, Mo, Ti, Al had bcc structure. Ta/Dy, Ta/Fe films structure was characterized as beta-Ta and Ta/Zr and Ta/Hf films consisted of a mixture of bcc Ta and beta-Ta. The Me and Ta layers had preferred orientation of close-packed planes parallel to the substrate plane (the [111], [110], [001] planes for the fcc, bcc, hcp metals correspondingly). The shortest interatomic distances (SID) in the Me are the shortest distances between the atoms in these planes. The correlation between beta-Ta formation in Ta/Me bilayers and mismatching of the SID in bcc Ta and in Me was found. Results of Ta films crystal structure investigations will be presented and discussed. @FootnoteText@ @footnote 1@ 1. L.V. Kozlovsky. Istrum. Experim. Techniq., 38, iss. 3, pt. 2, 417, (1995).