Rasoul Malekfar, Hamid Motahari, Jalal Rohollahnejad, Fatemeh Sahraiyan

Raman, Dielectric and Optical Investigations of DLC Thin Films

Surface Review and Letters 16 (2009) 731–736

Diamond-like carbon, DLC, thin films which is an amorphous hydrogenated form of carbon, a-C: H, has been synthesized by CVD method. SEM imaging, back-scattering Raman spectroscopy and reflected FT-IR spectroscopy have been used for characterization of the synthesized thin films. Kramers-Kronig dispersion relations have been used for the calculation of dielectric and optical parameters, which include the real and imaginary parts of the refractive and dielectric indices. In Raman spectroscopy, two obvious, wide and almost symmetrical peaks around 1355 cm^-1 (D mode) and 1520-1550 cm^-1 (G mode), clarify the formation of a-C:H thin film. Reflected spectra of thin films, in the spectral region of 400-4000 cm^-1, have been recorded by the near normal FTIR reflection spectroscopy and show some peaks which can be assigned to the bending of sp³ C-C, sp³ or sp² CH. The calculated data show that dielectric and optical parameters are almost independent of wavenumber.

Cited Articles

1. Franta D., Nečas D., Zajíčková L., Buršíková V.,
   Limitations and possible improvements of DLC dielectric response model based on parameterization of density of states,
   Diamond and Related Materials 18 (2009) 413–418