Effect of substrate temperature on the physical properties of copper nitride films by r.f. reactive sputtering

Deposition of copper nitride films are of significant interest because of t heir low thermal stability and semiconducting characteristics resulting in emerging applications in optical memories and laser writing. Copper nitride films are deposited by 13.56 MHz r.f. reactive sputtering (in the nitrogen plasma environment), keeping the substrates at 30 degreesC (no deliberate heating of the substrate), 75 degreesC and 150 degreesC. Crystalline phases of the films are identified by grazing angle X-ray diffraction (GAXRD) tec hnique. With an increase in substrate temperature, the film orients strongl y towards the (100) plane of the Cu3N phase. Surface morphology of the film s studied by atomic force microscopy (AFM) indicates an increase in grain s ize and a decrease in surface roughness in the films with increasing substr ate temperature. Agglomeration effect of grains are observed at the substra te temperature corresponding to 75 degreesC. The bandgap of the films are f ound by UV-VIS absorption spectroscopy varying from 1.3 to 1.76 eV. Stoichi ometry of the films is determined by heavy ion elastic recoil detection ana lysis (ERDA) technique with a DeltaE-E detector telescope. This study provi des insight into the importance of substrate temperature on the characteris tics of copper nitride films. (C) 2001 Elsevier Science B.V. All rights res erved.