Study of electron field emission and structural properties of nanostructured carbon thin films deposited by hot-filament-assisted reactive sputtering using methane gas

The electron field emission properties of the nanostructured carbon films were investigated. The films were deposited using an RF magnetron sputtering system with a hot filament. The target was a pure carbon disc and CH4 gas was introduced into the chamber to create plasma by applying an RF power of 100W at a relatively low pressure of 5×10−2Torr. The hot filament was made of tungsten wire, which was spiral-shaped and placed between the substrate and graphite target. The tungsten filament temperature was up to 2000°C during the deposition. Silicon, porous silicon (PS), and Pd-deposited PS (Pd/PS) were used as substrates on which the carbon films were formed at the temperature of 700°C. The characterizations of the films were investigated by scanning electron microscopy. Electron field emission of the films were characterized and an emission current density reached about 3.58×10−3A/cm2 at an electric field of 15V/μm for the carbon film deposited on Pd/PS substrate.