Deposition of diamond-like carbon using compact electron-beam-excited plasma source

We have deposited hydrogenated amorphous carbon (a-C:H) films called diamond-like carbon (DLC) on an electrically floating disk using a compact electron-beam-excited plasma (EBEP) employing toluene and ethylene as feed gases. Since the EBEP source enables us to control the ion sheath bias on the floating substrate by changing the electron-beam energy, the substrate ion bombardment energy needed to form the DLC film can be determined without applying an additional bias power supply such as RF. The relationship among the DLC film properties, the deposition rate and the electron-beam acceleration voltage for both feed gases has been investigated. In order to achieve uniform deposition on a disk of 80 mm diameter, the optimization of the compact EBEP source has been examined as well. A high-quality DLC film with good film uniformity on the disk was synthesized at high acceleration voltage employing toluene gas.