AVS 46th International Symposium
    Vacuum Metallurgy Division Tuesday Sessions
       Session VM+TF-TuM

Paper VM+TF-TuM8
Carburizing of Tantalum by Radio-Frequency Plasma Assisted CVD

Tuesday, October 26, 1999, 10:40 am, Room 620

Session: Ionized Plasma and Chemical Vapor Deposition
Presenter: A. Raveh, NRC-Negev, Israel
Authors: A. Rubinshtein, Ben-Gurion University
A. Raveh, NRC-Negev, Israel
J.E. Klemberg-Sapieha, Ecole Polytechnique, Canada
L. Martinu, Ecole Polytechnique, Canada
Correspondent: Click to Email
Tantalum carbide has a great potential as an alternative to tantalum and tantalum oxide for applications requiring thermal stability and corrosion resistance. In the present work we are studying hard TaC layers prepared by inductive rf plasma-assisted CVD (IPACVD) in different gas mixtures containing argon, methane, and hydrogen. The IPACVD approach combines plasma-induced diffusion with chemical vapor deposition. Maximum temperature of the tantalum substrate measured during 6 hours of processing time was 900 degC. Microstructure of the TaC layers was characterized by XRD, AFM, AES, and XPS, and the mechanical properties were studied by micro- and nanoindentation techniques. Close correlation between carburizing parameters, microstructure and mechanical properties of the layers has been established. The best mechanical performance in terms of elasto-plastic properties (microhardness of about 25 GPa) were obtained for several micrometers thick TaC films prepared at rf power levels between 1.6-2.0 kW and pressures between 40 and 60 mTorr. The effect of gas composition, rf power and substrate temperature on the layer composition (TaC/Ta@sub 2@C phase ratio), and the mechanical behavior will be presented and discussed.