AVS 47th International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS1-ThA

Paper PS1-ThA9
Study of Defects Induced on Graphite Surface by Low Pressure Argon Plasma

Thursday, October 5, 2000, 4:40 pm, Room 310

Session: Plasma-Surface Interactions II
Presenter: A.L. Thomann, GREMI (CNRS), France
Authors: A.L. Thomann, GREMI (CNRS), France
P. Brault, GREMI (CNRS), France
H. Estrade-Szwarckopf, CRMD (CNRS), France
B. Rousseau, CRMD (CNRS), France
C. Andreazza-Vignolle, CRMD (Universite d'Orleans), France
P. Andreazza, CRMD (Universite d'Orleans), France
Correspondent: Click to Email
Since several years, we have been studying ultra-thin metal film deposition by a plasma sputtering method giving rise to low deposition rates (< 5 Å/min). Previous works have shown that the metal growth mode depends on the deposition conditions, which are tailored by the plasma conditions. For example, Pd metal has been found to form either 3D nanometer clusters, or very thin continuous layers.@footnote 1@ These results are interesting because they evidence that, with this deposition method, the film morphology may be easily chosen for a given application. Our aim is now to study how argon plasma pretreatment may modify the substrate surface state and thus, change growth modes. This will lead to an integrated plasma process allowing surface preparation followed by metal deposition. To study the induced defects, a plasma reactor has been added to an UHV-chamber equipped with STM, AFM, XPS and UPS analyses. This system allows chemical, electronic and morphological characterizations of the substrates before and after plasma treatments of different durations (30 s to 1 h). For these experiments, Highly Oriented Pyrolytic Graphite (HOPG) substrate has been used because it has been thoroughly studied as well as the surface defects created by ions beam techniques. First results show that small (D= some Å) and large (D= tens of Å) size defects are created on HOPG surface, that appear on STM images as hillocks of some Å height. Close to the large defects, a graphite lattice superstructure is observed. After a long lasting plasma treatment, the C1s XPS spectrum of the HOPG surface is completely modified ; on STM images, the hexagonal lattice is no longer observed and the superficial atomic structure appears as highly distorted although with a very small roughness (< 2 Å). @FootnoteText@ @footnote 1@ P. BRAULT et al, Recent Research Development in Vacuum Sci. And Technol., 2, R.A. Gottscho & R.J. Pearton Eds. (Transworld Research Network, India, 1000).