J.A. Dı́az

Copper nitride films produced by reactive pulsed laser deposition

Deposition of copper nitride films is of importance due to its technological applications. Copper nitride thin films are deposited by reactive pulsed laser deposition (nitrogen environments) on silicon substrates at room temperature. The resultant films are in situ characterized by Auger (AES), X-Ray Photoelectron (XPS) and Reflection Electron Energy Loss spectroscopies (REELS). The chemical bond is strongly linked to the stoichiometry, and both can be controlled by the deposition pressure. The mass density achieved for Cu3N is 5.91 g cm−3, close to the theoretical value of 5.84 g cm−3. We conclude that this deposition method offers a means for fine-tuning the properties of copper nitride.

Tungsten nitride films grown via pulsed laser deposition studied in situ by electron spectroscopies

Abstract Tungsten nitride (WNx) films were grown on silicon and glass slide substrates by laser ablating a tungsten target in molecular nitrogen ambient. By in situ Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS), the films density, elemental composition and chemical state were determined. Ex situ, the films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Also, the transmittance and resistivity of the film on glass substrates were determined. The results show that the reaction of tungsten and nitrogen is effective; the nitrogen is integrated in the tungsten matrix changing gradually the electronic configuration, chemical states and film properties. Since with this preparation method the obtained films are of high quality, low resistivity and dense, this makes attractive to growth tungsten nitride films for technological applications.

Growth of beryllium nitride films by pulsed laser deposition; dielectric function determination

Beryllium nitride thin films, which are candidates for optoelectronic applications, have been grown by pulsed laser deposition on silicon substrates. The films were prepared by ablating a beryllium foil in N environment at several pressures and substrate 2 temperatures. Real-time ellipsometric monitoring for the period of deposition were carried out by a multiwavelength ellipsometer in the 1.625(hn(4.405 eV photon-energy range. After its completion, the films were characterized in situ by electron spectroscopies and ex situ by atomic force and scanning electron microcopies. A model for the growth of beryllium nitride was applied to reproduce the optical measurement and concurrently, the refractive index from the visible to the near ultraviolet spectral region was calculated. The estimated optical bandgap correlates closely with previously published theoretical results. 2003 Elsevier Science B.V. All rights reserved.