Chemical synthesis and surface morphology of amorphous hydrogenated carbon nitride film deposited by N₂/CH₄dielectric barrier discharge plasma

A dielectric barrier discharge of N2:CH4 mixture was operated at 500 mbar was employed to deposit poly-amide (HCN x ) film, under low input power and atmospheric pressure. The top surface layer of amorphous hydrogenated carbon nitride (a-HCN x ) is analyzed by X-ray photoelectron spectroscopy (XPS). Bulk a-HCN x is analyzed by means of fourier transform infrared (FTIR) spectroscopy. The deposited polymer having triple bond (–C≡N/–C≡C–) at ∼2180 cm−1 and carbonyl-amide group –(C=O)NH– at ∼1680 cm−1, were synthesized by FTIR spectroscopy to elucidate the nature of the products formed from N2/CH4 mixture. The nitrile group (–C≡N/–) is decreasing with the elevated annealing temperature is obtained from FTIR spectrum. Shake-up satellite peaks are observed in XPS spectrum at room temperature. The shake-up peaks disappear gradually as the annealing temperature is increased from 50 to 300 °C. Simultaneously, the chemical shift of 1s electron shifted to its own advantageous position. The surface roughness (Root Mean Square, RMS) of the HCN x film is changing from 5.3 to 28.2 nm as the annealing temperature increases from room temperature to 300 °C.