Carbon nitride films prepared by guanazole laser ablation in ammonia atmosphere Original Research Article

Carbon nitride thin films were deposited using an ArF excimer laser to ablate a target of 3,5 diamino 1,2,4 triazole (guanazole) in a reactive atmosphere of ammonia. Films were obtained at room temperature onto crystalline silicon and aluminium substrates. The dependence of the film properties on the ammonia pressure is reported. Films were characterized systematically by profilometry, Fourier Transform infrared and energy dispersive X-ray (EDX) spectroscopies. Infrared spectra are dominated by a broad absorption band from 1300 to 1650 cm−1, and a peak located at 2165 cm−1 indicating that nitrogen is bonded to carbon in different configurations. The broad band at high wavenumbers (3100–3500 cm−1) is attributed to NHx stretching modes revealing the presence of hydrogen in the films. Additional X-ray photoelectron spectroscopy measurements corroborate the presence of carbon bonded to nitrogen. Composition estimated by EDX shows that as the ammonia pressure is increased, higher concentration of nitrogen is incorporated into the films, reaching values up to 53 at% for NH3 pressures > 1 Torr. Post-deposition thermal treatments up to 500 °C induce structural changes and promote the CN bond formation. Simultaneous analyses of the effused gases from the film during the thermal annealing are also reported.