A mathematical model of the ion-beam growth of tetrahedrally-bonded carbon nitride

We present a model to calculate the threshold ion bombarding energy required for overall rearrangement of target atoms in the ion-beam-enhanced deposition of carbon nitride films. This model describes the transient modification of the film-bonding configuration by successive individual ion impact events. Each ion impact is treated as a cylindrical thermal spike with a finite initial width, taking into account energy loss and energy dissipation processes. It is shown that the rearrangement of atoms during a cylindrical spike is the dominant mechanism leading to the formation of carbon nitride phase. The predicted characteristic energy range in which bombardment of the target atoms has at least one rearrangement is in good agreement with the experimental observation. The sp(3) bonding structure is dominant in carbon nitride films synthesized by ion-beam-enhanced deposition technique. It is suggested that one way to enhance the potential for formation of sp(3) configuration is to increase the thermal energy of target atoms to promote their rearrangement.