RAMAN, DIELECTRIC AND OPTICAL INVESTIGATIONS OF DLC THIN FILMS

Abstract

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.