The characteristic of as-grown and post-annealed nitrogen doped amorphous carbon thin films deposited by surface wave microwave plasma enhanced chemical vapor deposition method

Nitrogen doped amorphous carbon (a-C:N) thin films were deposited on silicon and quartz substrates by microwave surface-wave plasma chemical vapor deposition (SWMP-CVD) technique at low temperatures (< 100 degrees C). We used argon (Ar), camphor dissolved in alcohol, and nitrogen (N) as carrier, source, and dopant gases, respectively. Optical band gap (E-g) decreased from 4.1 to 2.4 eV when the N gas concentration increased from 0% to 4.5%. The films were annealed at different temperatures ranging from 150 degrees C to 450 degrees C in Ar gas environment to investigate the optical and electrical properties of the films before and after annealing. Both Eg and electrical resistivity (rho) decreased dramatically up to 0.95 eV and 57x 10(3) Omega cm at 450 degrees C annealing. The structural modifications of the films leading them to become more graphitized as a function of the annealing temperature were confirmed by the characterization of Raman spectra.