Optical and morphological properties of laser photo-deposited hydrogenated CNx thin ®lms

The optical and morphological properties of hydrogenated carbon nitride thin ®lms obtained by ArF excimer laser photodeposition (l ˆ 193 nm) from different ammonia/acetylene mixtures were investigated. The optical properties of the ®lms depend on the nitrogen content. The band gap deduced from measurements of the optical absorption coef®cient in the UV± VIS spectrum is found to be superior to 2.3 eV. Film thicknesses and refraction indexes were investigated by m-lines spectroscopy. The refraction index varies from 1.66 to 1.72. The microstructure of the deposited ®lms as revealed by scanning and transmission electron microscopy is discussed as a function of the deposition parameters. # 2000 Elsevier Science B.V. All rights reserved