On the growth mechanism of pulsed laser deposited carbon nitride films

Carbon nitride films have been deposited by ArF excimer laser ablation of a graphite target in the 10−2 to 100 Pa N2 pressure range. Arrival rates of the constituting elements, mass densities and apparent growth rates have been derived from areal densities of both carbon and nitrogen atoms, determined by ion beam techniques, and film thicknesses, measured by a mechanical stylus. Below 5 Pa the film building blocks are atoms and molecules while above ∼50 Pa the formation and interaction of clusters and particles determine the film growth. The results reveal that the formation, composition and microstructure of carbon nitride films fabricated in this process window is governed by gas-phase processes.