HOW PLASTIC-DEFORMATION CAN PRODUCE TEXTURE IN GRAPHITIC FILMS OF BORON-NITRIDE, CARBON NITRIDE, AND CARBON

The graphitic forms of carbon, boron nitride, and carbon nitride grown in energetic film-deposition processes or processed using ion irradia tion often possess an in-plane c-axis texture. In this texture the bas al planes of the graphitic material are perpendicular to the substrate . We show that the in-plane c-axis texture can be produced through pla stic deformation as a mechanism to relieve the large ion-induced compr essive stresses in these materials. Specifically, basal-plane slip and kinking processes would produce a rotation of the c-axis towards the plane of biaxial compressive stress. Once the c-axis has rotated to li e in the plane of the substrate, further deformation by basal-plane sl ip cannot occur. Then, in the absence of additional stress-reduction p athways, the stress level will rise if the material undergoes further compressive elastic strain. The possible relationship between this str ess build-up and nucleation of high-density phases, such as cubic boro n nitride, is briefly discussed. (C) 1997 Elsevier Science S.A.