Optical properties in infra-red region of nitrogen-incorporated amorphous carbon films

Nitrogen-incorporated amorphous carbon (a-C:N) films arc prepared by filtered are deposition. Optical properties of a-C:N films were characterized by infra-red reflectance spectrometer. The experimental results show that the reflectivity of a-C:N films increases as the nitrogen content increases. Using detailed theoretical analysis and computer simulation, the complex dielectric constant epsilon=epsilon(1)+i epsilon(2),, refractive index (n) over tilde=n+ik and absorption coeifficient alpha of a-C:N films in infra-red region were investigated. Simulation results indicate that the optical constants of a-C:N show a considerable variation with wave number and nitrogen content. The a-C:N film with a low nitrogen content possesses a low <(epsilon)over tilde> and corresponding low (n) over tilde and alpha values. The variation of optical properties and optical constants of a-C:N films may be due to the development of graphite-like structure with the increasing of nitrogen content in these films. (C) 1998 Elsevier Science S.A.