Structural, electrical, and optical properties of amorphous carbon nitride films prepared using a hybrid deposition technique

Amorphous carbon nitride (a-CN_x) thin films were prepared using a hybrid deposition technique (HDT), which is a combination of RF and DC magnetron co-sputtering of a graphite target. We varied the nitrogen gas flow ratio (GFR, N₂/N₂ + Ar) during deposition to prepare a-CN_x films with various nitrogen concentrations. The film properties were characterized using X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The optical and electrical properties were also investigated. For 0.3 < GFR < 1, the optical band gap and resistivity increased with increasing nitrogen concentration (x = N/C) and sp³ C-N bonding fraction in the films. Compared to carbon nitride films with a comparable nitrogen content prepared by RF and DC sputtering, the optical band gap and resistivity of a-CN_x films prepared by HDT were narrower and lower, respectively.