Preparation of Carbon Films by Hot-Filament-Assisted Sputtering for Field Emission Cathode

摘要

Carbon thin films on a silicon substrate were prepared by DC magnetron sputtering method with a tungsten hot filament. In order to investigate the effects of the hot filament on film properties, the carbon thin films were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and electron emission measurements. The tungsten atoms were evaporated from the hot filament and incorporated in the carbon film. The field emission measurement showed that the incorporation of tungsten was effective in reducing the turn-on voltage. The value of the turn-on voltage was 3.0 V/μm for the sample prepared with a tungsten filament heated at the temperature of 2000℃. The intentional insertion of a tungsten layer between the carbon film and the substrate was effective in obtaining a carbon film with a low turn-on voltage for the field emission.