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Title: Interactions of low energy reactive ions with surfaces. IV. Chemically bonded diamond-like films from ion-beam deposition

Journal Article · · J. Chem. Phys.; (United States)
DOI:https://doi.org/10.1063/1.454524· OSTI ID:5372000

Low energy (10--300 eV) mass-selected C/sup +/ ion beams are used to deposit thin carbon films on surfaces of Si(100), Ni(111), Ta, W, and Au in a UHV environment at room temperature. The films are characterized by Auger electron spectroscopy (AES), x-ray and UV photoelectron spectroscopy (XPS and UPS), valence level electron energy loss spectroscopy (ELS), K-shell ionization loss spectroscopy (ILS), and ellipsometry. The initial monolayer of the deposited film is in the form of a carbide layer which is chemically bonded to the substrate atoms. The film evolves gradually over the next several layers deposited, through intermediate structures, into a diamond-like structure. The diamond-like structure is confirmed by comparing the results of the above spectroscopic measurements with those of pure diamond and graphite and by referring to band structure calculations. A phase diagram, prepared as C/sup +/ ion dose vs C/sup +/ kinetic energy E/sub k/, shows the regions of the different structures. The optimum C/sup +/ energy range for formation of the diamond-like structure is 30--175 eV. Below 10 eV the final diamond-like structure has not been attained and above 180 eV there is a sharp increase in the dose required to attain this final structure. The films are found to be free of impurities, inert to O/sub 2/ chemisorption, structurally stable up to 350 /sup 0/C, have a low sputtering yield, and have a sharp interface with the substrate surface. The mechanism of film deposition and growth is discussed.

Research Organization:
Department of Chemistry, University of Houston, Houston, Texas 77004
OSTI ID:
5372000
Journal Information:
J. Chem. Phys.; (United States), Vol. 88:9
Country of Publication:
United States
Language:
English