PECVD of hydrogenated diamond like carbon films from CH4-Ar mixtures: growth chemistry and material characteristics.

Hydrogenated diamond-like carbon film growth from CH4-Ar plasmas has been investigated under the effect of negative DC self-bias voltage. The deposition rate, the optical emission spectroscopy data and the material properties have been examined for understanding the growth mechanism. It is suggested that the sputter-etching process in competition with the growth process is responsible for the decrease of deposition rate at high bias voltage (i.e. high radio frequency power and low pressure). The clear and important roles of Ar ions and H atoms in sputter-etching process are well evidenced by the joined analysis of deposition rate, emitting species intensities and modified material properties.