Identification of Chemical Bonds on Upper Layers of DLC Using Auger Spectroscopy and XPS

Hydrogen free DLC were deposited by solid carbon arc sputtering system. The DLC samples have been examined by N(E)CKVV Auger spectroscopy and Electron energy loss spectra of C1s XPS (EEL of C1s). According the CKVV data, concentration of the sp3 bonds averages 60% - 70%. The EEL of C1s XPS spectra have not π - plasmon feature that is the inherent peculiarity of C=C bonds. Obviously, these data are showing the evidence of absence of the sp2-bonds in traditional understanding. The DLC samples were heated in-situ up to 800K or Ar ion etched. The CKVV showed the transformation of sp3 bonds from 70% to 0% but EEL of C1s XPS did not show the π-plasmon formation. The results are showing the evidence of DLC decomposition only on upper layers.