AVS 47th International Symposium
    Thin Films Tuesday Sessions
       Session TF-TuP

Paper TF-TuP9
Deposition of W Films using Different Underlayers

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: V. Pashkevich, University of Daugavpils, Latvia
Authors: L.V. Kozlovsky, University of Daugavpils, Latvia
A. Antinsh, University of Daugavpils, Latvia
V. Pashkevich, University of Daugavpils, Latvia
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It is known that the formation of beta-Ta crystalline phase in sputtered Ta films depends on the nature of the substrate or underlayer. Comparison of our data as well as of results of various authors reveals the correlation between beta-Ta formation in Ta/Me bilayers and mismatching of the shortest interatomic distances (SID) in bcc Ta and in Me. Beta-Ta phase presents in the Ta films when SID mismatching greater of 9%. The aim of the present work was to determine whether beta-W formation in W/Me bilayers occurs at such conditions. We deposited 100 nm Me/X nm W (Me: Nb,Al, Fe, Zr, Hf, Dy ; X = 20,50, 100, 200 nm) bilayers on near room-temperature glass substrates in a Xe discharge at a pressure of (7 - 9) x10@super -4@ Torr using Penning discharge sputtering devices. The base pressure was nearly 5x10@super -9@ Torr.10 nm C underlayer was deposited on substrates at the same vacuum conditions before bilayers deposition. The structure of the films was investigated by X-ray diffraction (XRD). In the case of Nb and Al the SID mismatching is less of 4% but for other metals it is in the interval (10 - 28)%. Wolfram layers structure was characterized as bcc W. XRD profiles for all bilayers had no peaks corresponding to beta-W. W films on Nb and Fe had texture (110). Preferred orientation of {110} and {211} planes parallel to the substrate plane was found in W layers in the case of Al, Zr, Hf, Dy underlayers. The results of present work have shown that beta-W formation in Me/W bilayers is not dependent on underlayer. Data of the bilayers crystal structure investigations will be presented and discussed.