Structural, electrical, and optical characterization of nanocrystalline diamond films deposited by HFCVD method

Abstract

The structure, electrical and optical properties of nano-crystalline diamond (NCD) films deposited by hot-filament chemical vapor deposition (HFCVD) method, are reported. The influence of the carbon concentration during the film deposition on the Raman scattering, optical gap, optical constants (n and k) and dark-current is investigated. Under a higher carbon concentration during deposition, the NCD film obtained with a smaller grain size, has a lower optical gap, refractive index and electrical resistivity. These changes with the carbon concentration are attributed to the high amount of sp 2 bonded carbons and other non-diamond phase, which is confirmed by Raman scattering measurements.