Binding state transformation in high temperature synthesized CN thin films

We have obtained tetrahedral carbon nitride (CN) films by r.f. plasma pulse d laser deposition at 600 degrees C. As we increase the magnitude of the ne gative d.c. bias voltage of the Si substrate, predominant formation of tetr ahedral CN bonds and suppression of graphite-like CN state are found. By me ans of such a bias voltage, CN films with adaptable fraction of graphite-li ke and tetrahedral CN bonds can be tailored according to requirement. All t hese films are stable to annealing at 800 degrees C. Likewise, annealing of CN films prepared at room temperature (RT) revealed a novel transformation of CN binding state. The graphitelike CN bond is ruptured and converted in to the aliphatic-like CN state. The tetrahedral CN bond contained inside th e RT-prepared samples remained after annealing. (C) 1999 Elsevier Science S .A. All rights reserved.