AVS 47th International Symposium
    Thin Films Friday Sessions
       Session TF+NS-FrM

Paper TF+NS-FrM8
Nanophase Metal - Metal Oxide Films Deposited from a High-rate, Nanoparticle Beam

Friday, October 6, 2000, 10:40 am, Room 203

Session: Nanostructured Thin Films
Presenter: F.K. Urban III, Florida International University
Authors: F.K. Urban III, Florida International University
A. Hosseini-Tehrani, Florida International University
P.D. Griffiths, Florida International University
A. Khabari, Florida International University
Y.-W. Kim, University of Illinois
I. Petrov, University of Illinois
L. Wei, University of Illinois
Correspondent: Click to Email
While interest in nanophase films deposited in vacuum from nanoparticle beams dates back to the early 1970s, development of suitable sources for such beams has been difficult. A rapidly increasing number of different materials are now being used to deposit nanophase films, from a few tenths to a micrometer in thickness. The new method employs DC magnetron sputtering and condensation of a conductive target material into a helium and argon gas mixture in a flow rate ratio of up to 0.12 at total pressures between 0.7-0.8 Torr. A low velocity beam of the gas and nanoparticles is formed as they escape through a 3 mm-diameter converging-diverging exit nozzle consecutively into differentially pumped chambers maintained at pressures less than 10-3 and less than 10-4 Torr, respectively. Results to date confirm a typically oxygen-containing nanophase film structure. A set of new metal and doped semiconductor elements including Ag, Al, Au, Co, Cr, Cu, Fe, Mo, Nb, Ni, Pt, Si, Sn, Ta, W, and Zr have just been deposited. To our knowledge, some of these are deposited in vacuum for the first time and details on their nanostructure, composition, and materials properties are just now being learned and will be reported. To date, all films are nanocrystalline with grain sizes ranging from 1 to 20 nm and have a porous structure metallic densities, determined from combined Rutherford backscattering and film thickness measurements, in the range of 15-80% of the bulk densities. The effects of synthesis chamber wall cooling and gas conditions as well as starting material vapor pressure, melting point, and condensation energies will be presented. New findings on material properties will also be presented.