TEMPERATURE-DEPENDENCE OF THE FORMATION OF HIGHLY TETRAHEDRAL A-C-H

Deposition from a low pressure plasma beam source creates a highly tet rahedral form of hydrogenated amorphous carbon (ta-C:H) which is analo gous to the ta-C formed by deposition from a filtered cathodic are 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 temper atures above a threshold value, which is found to decrease with increa sing ion energy. The films above the threshold are mainly sp(2) bonded , with graphitic layering and high roughness. The variation of the fil m density with the ion energy and T-s is consistent with deposition oc curring by subplantation.