Semiquantitative subplantation model for low energy ion interactions with surfaces. II. Ion beam deposition of carbon and carbon nitride

Abstract

The semiquantitative subplantation model developed in article I of this series [J. Vac. Sci. Technol. A 16, 444 (1998)] is applied to model experimental data for the systems of C+ and N+ ion interactions with graphite, the deposition of diamondlike carbon (DLC) films from C+ ions, and the deposition of carbon nitride (CxNy) films from C+ and N+ ions. The success of the model is based on its ability to provide semiquantitative interpretations of the physical phenomena underlying experimental data from several sources that had previously been interpreted only qualitatively. These phenomena include the effects of ion kinetic energy, ion beam fluence, substrate temperature, radiation enhanced diffusion, penetration thresholds, displacement thresholds, substrate density, and bonding sites. The model allows one to draw previously unexpected conclusions about the interaction mechanisms and to establish quantitative estimates for some previously unknown physical parameters. The results indicate that there is a value of the C+ and N+ ion penetration threshold, ∼7 to 8 eV, which is applicable to graphite, CxNy, and DLC surfaces. The production of sp3 bonded structures is determined by a balance between the beneficial effects (subsurface deposition, enhanced diffusion, densification) and the deleterious effects (damage) of energetic particle beams.