AVS 49th International Symposium
    Thin Films Monday Sessions
       Session TF-MoA

Paper TF-MoA7
Super-Smooth Indium-Tin Oxide Thin Films by Negative Sputter Ion Beam Technology

Monday, November 4, 2002, 4:00 pm, Room C-101

Session: Transparent Conductive Coatings
Presenter: M.H. Sohn, Plasmion Corporation
Authors: M.H. Sohn, Plasmion Corporation
D. Kim, Plasmion Corporation
N.W. Paik, Plasmion Corporation
S.J. Kim, Plasmion Corporation
S. Gupta, KDF
Correspondent: Click to Email
A new ionized PVD, Negative Sputter Ion Beam technology, is described for the deposition of super-smooth indium-tin oxide (ITO) thin films with highly transparent and conductive properties at near-room temperature deposition. A limited amount of cesium vapor injected onto a conventional sputtering target surface lowers the work function of the target and produces a negatively charged sputter ion beam. The negative sputter ion beam carries the kinetic energy defined by the potential difference between the cathode and substrate. A negatively-charged sputter ion beam was produced by retrofitting an ITO magnetron sputtering cathode with a cesium vapor injector capable of releasing controlled amounts of cesium vapor into the plasma during deposition. Experiments were performed in a down-sputtering scanning batch tool (KDF 902GT). Using this highly energetic deposition process, ITO thin films have been obtained at near-room temperature (less than 50 °C) with super smooth surface (< 1 nm RMS), resistivity of 4 x 10@super -4@@ohm@cm, and transmittance higher than 90% (at wavelength 550 nm). Baseline ITO depositions were also carried out under the same sputtering conditions with no cesium injected, as a comparison. In this paper, film properties such as resistivity, transmittance over the visible spectrum, and surface roughness will be detailed as a function of cesium partial pressure during deposition. The significance of a high quality, low temperature ITO coating process applied to polymer substrates will be discussed.