Applied Surface Science, Vol.252, No.22, 8001-8004, 2006
Study of the structure and electrical properties of the copper nitride thin films deposited by pulsed laser deposition
Copper nitride thin films were prepared on glass and silicon substrates by ablating a copper target at different pressure of nitrogen. The films were characterized in situ by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and ex situ by X-ray diffraction (XRD). The nitrogen content in the samples, x = [N]/[Cu], changed between 0 and 0.33 for a corresponding variation in nitrogen pressure of 9 x 10(-2) to 1.3 x 10(-1) Torr. Using this methodology, it is possible to achieve sub-, over- and stoichiometric films by controlling the nitrogen pressure. The XPS results show that is possible to obtain copper nitride with x = 0.33 (Cu3N) and x = 0.25 (Cu4N) when the nitrogen pressure is 1.3 x 10(-1) and 5 x 10(-2) Torr, respectively. The lattice constants obtained from XRD results for copper nitride with x = 0.25 is of 3.850 angstrom and with x = 0.33 have values between 3.810 and 3.830 angstrom. The electrical properties of the films were studied as a function of the lattice constant. These results show that the electrical resistivity increases when the lattice parameter is decreasing. The electrical resistivity of copper nitride with x = 0.25 was smaller than samples with x = 0.33. (c) 2005 Elsevier B.V. All rights reserved.