ON THE DETERMINATION OF THE SP(3) TO SP(2) RATIO IN DIAMOND-LIKE CARBON THIN-FILMS

The carbon bonding ratio in diamond-like carbon (DLC) thin films has b een estimated from the epsilon(2) spectra obtained by spectroscopic el lipsometry. A method has been developed to find out the atomic fractio ns of sp(3)- and sp(2)-bonded carbon atoms by combining the various fe atures of the existing methods. The atomic fraction of sp(3)-bonded ca rbon atoms has been determined by fitting the gaussian curves in the e xperimentally observed epsilon(2) spectra in the low energy range (<4 sV). The atomic fraction of sp(3)-bonded carbon atoms has been determi ned by calculating the total electron density in the DLC matrix. The a mount of hydrogen present in DLC films has also been taken into accoun t. (C) 1997 Elsevier Science S.A.