Temperature dependence of the formation of highly tetrahedral a-C:H

Abstract Deposition from a low pressure plasma beam source creates a highly tetrahedral form of hydrogenated amorphous carbon (ta-C:H)) which is analogous to the ta-C formed by deposition from a filtered cathodic arc or mass-selected ion beam. The properties of ta-C:H have been studied as a function of the substrate deposition temperature T s and ion energy using electron energy loss spectroscopy, X-ray diffraction and atomic force microscopy. The density decreases suddenly for deposition temperatures above a threshold value, which is found to decrease with increasing ion energy. The films above the threshold are mainly sp 2 bonded, with graphitic layering and high roughness. The variation of the film density with the ion energy and T s is consistent with deposition occurring by subplantation.