Cathodoluminescence of the a-C:N films deposited by a filtered cathodic arc plasma system

Amorphous carbon nitride (a-C:N) films were successfully synthesized on silicon using a 90°-bend magnetic filtered cathodic arc plasma (FCAP) system. ESCA analysis demonstrated that the N/C ratios reached 1.08. Many investigations on photoluminescence (PL) spectra of diamondlike carbon films have been performed, but cathodoluminescence (CL) spectra have seldom been discussed. This work investigated a-C:N films using the CL spectra at 300 K. This work presents CL spectra of a-C:N films obtained at 1.5-3.5 eV and verifies luminescence from the a-C:N films in the visible region. The most prominent luminescence in the CL spectra from the a-C:N films has two peaks centered ∼2.67 eV (blue light) and ∼1.91 eV (red light), but the a-C film yielded only the band at ∼1.91 eV. These optical emissions are intrinsic and extrinsic to the a-C:N film and are sensitive to the content of nitrogen.