Carbon nitride thin films deposited by nitrogen-ion-assisted KRF excimer ablation of graphite

Carbon nitride thin films were deposited on silicon wafers by pulsed KrF Excimer (wavelength 248 nm, duration 23 ns) ablation of graphite. Different laser fluences and pressures of the nitrogen atmosphere were used in order to achieve a high nitrogen content in the deposited thin films. A Kaufmann-type ion source was used to produce a nitrogen ion beam to assist the deposition process. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to identify the binding structure and the content of the nitrogen species in the deposited thin films. The thin films deposited in nitrogen atmosphere had N/C ratio of 0.42, similar to those deposited with assistance of nitrogen ion beam bombardment with N/C = 0.43. A high content of C=N double bond was indicated in both thin films deposited in nitrogen atmosphere and with nitrogen ion-beam assistance. The dependence of the optical band gap on nitrogen ion energy was studied by Ellipsometry.