BONDING PROPERTIES OF RF-CO-SPUTTERING AMORPHOUS GE-C FILMS STUDIED BY X-RAY PHOTOELECTRON AND RAMAN SPECTROSCOPIES

The bonding properties of hydrogenated amorphous germanium-carbon (a-G e1-xCx:H) alloy films, deposited by the rf-co-sputtering technique, we re measured by Fourier transform infrared, micro-Raman and X-ray photo electron spectroscopies. Films with carbon content in the 0 to 100 at. % range were prepared under the same deposition conditions used to pre pare a-Ge:H films. The infrared spectra revealed that the carbon is bo nded in both sp(3) and sp(2) configurations. XPS measurements show a c hemical shift of the binding energy of the Ge 3d core electrons toward larger energies as the carbon content increases, while the line-width remains almost constant. On the other hand, the peak associated with the C 1s orbital displays a doubler related to the C-Ge and C-C bonds. The Raman spectroscopy data are analyzed over a wide frequency range of the Stokes scattering for different alloy compositions. (C) 1998 El sevier Science B.V. All rights reserved.