The Effect of Annealing on the Field Emission Properties of Amorphous CN(x) Films

The carbon nitride films deposited by r.f magnetron sputtering in pure N2 discharge were annealed in vacuum up to 900 C. The chemical composition and bonding structure of the films were studied using X-ray photoelectron spectroscopy (XPS), Fourier Transformation Infrared (FTIR). The effects of the thermal annealing on bonding structure and the electron field emission characteristics of CN(sub x) films were investigated. It is found that the sp(sup 2) carbon bonds and N content in CN(sub x) films are closely related to field emission of CN(sub x) films. The results show that thermal annealing treatment cause a great loss of N content and a larger formation of sp2 carbon bonds in CN(sub x) films, which would enhance significantly the field emission properties for the CN(sub x) films. The CN(sub x) films annealed at temperature of 750 C show the optimal electron emission properties. In addition, the correlation between the change in concentration of sp2 carbon bonds in the films induced by annealing and electron emission properties for the CN(sub x) films was discussed.