Field electron emission from HfNxOy thin films deposited by direct current sputtering

HfNxOy thin films were deposited on Si substrates by direct current sputtering at room temperature. The samples were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). SEM indicates that the film is composed of nanoparticles. AFM indicates that there are no sharp protrusions on the surface of the film. XRD pattern shows that the films are amorphous. The field electron emission properties of the film were also characterized. The turn-on electric field is about 14V/mum at the current density of 10muA/cm2, and at the electric field of 24V/mum, the current density is up to 1mA/cm2. The field electron emission mechanism of the HfNxOy thin film is also discussed.