Improvement of Field Emission Characteristics of Copper Nitride Films with Increasing Copper Content

A copper nitride (Cu₃N) thin film is deposited on a Si substrate by the reactive magnetron sputtering method. The XPS measurements of the composite film indicate that the Cu content in the film is increased to 80.82at.% and the value of the Cu/N ratio to 4.2:1 by introducing 4% H₂ into the reactive gas. X-ray diffraction measurements show that the film is composed of Cu₃N crystallites with an anti-ReO₃ structure. The effects of the increase of copper content on the field emission characteristics of the Cu₃N thin film are investigated. Significant improvement in emission current density and emission repeatability could be attributed to the geometric field enhancement, caused by numerous surface nanotips, and the decrease of resistivity of the film.