The mechanism of nitrogen depletion of N-rich Cu₃N thin films have been investigated as a function of the stopping power and irradiation angle. To this purpose, N-rich Cu₃N thin films with a thickness of ~100 nm were deposited by DC triode sputtering [1] and were irradiated with Cu at room temperature at energies ranging from 2.0 to 40.0 MeV by Cu. Thus, irradiation took place mainly in the electronic stopping power regime. The irradiation fluence was selected to be from 5x10¹¹cm^-2 up to 5x10¹⁴cm^-2, and the incidence angle was varied from 60º to 85º with respect to the sample normal. The irradiation-induced changes in the chemical composition, structural phases and surface morphology were characterized by ion beam analysis (IBA) techniques, X-ray diffraction (XRD), profilometry and atomic force microscopy (AFM), respectively. Elastic Recoil Detection Analysis (ERDA) reveals that in the lower fluence range no significant release of N takes place, but at higher fluence a prominent N release was observed. The release of nitrogen and the formation of secondary phases and metallic Cu are discussed on the basis of existing models.

[1] N. Gordillo et al. Jour. of Cryst.Growth 310 (2008) 4362.