Monoclinic carbon nitride phase coherently grown on Si (001) substrates

Carbon nitride films deposited on Si (001) substrates at room temperature b y XeCl laser ablation of graphite targets in low pressure (1, 5, 10 and 50 Pa) N-2 atmosphere at fluence of 12 J/cm(2) (similar to0.4 GW/cm(2)) have b een investigated by x-ray diffraction and transmission electron microscopy in order to study the structure of the films. The results showed that the s amples are constituted of a continuous amorphous film inside which microcry stals of a coherently grown CNx phase are dispersed. This phase is monoclin ic with the following lattice parameters: a=b=0.384 nm, c=0.302 nm, alpha=g amma =90 degrees, and beta =96.5 degrees. The CNx phase grows with the (001 ) plane coincident with the (001) plane of the Si substrate and with the [0 10](CNx) direction parallel to the [110](Si) one. (C) 2001 American Institu te of Physics.