THERMAL-STABILITY OF COPPER NITRIDE FILMS PREPARED BY RF MAGNETRON SPUTTERING

Copper nitride films were prepared by the rf magnetron sputtering meth od using Ar and N-2 as working gas. The nitrification degree of the fi lms was studied by changing the N-2 fraction or the substrate temperat ure under the N-2 fraction of 30%. The films deposited under different N-2 fraction were also annealed at temperature range of 100-300 degre es C in order to study the thermal stability of the films. X-Ray diffr action (XRD) and X-ray photoelectron spectroscopy (XPS) were used to c haracterize the films. It was shown that the films grow along the [100 ] orientation and the preferential growth becomes heavier with increas ing N-2? fraction. The size of the Cu3N grain is estimated to be on th e order of nanometers, and the grain size increases with increasing N- 2;? fraction. The Cu3N phase is thermally unstable in vacuum even at 1 00 degrees C. During the deposition under the N-2 fraction of 30%, the highest substrate temperature to form the Cu3N phase ranges from 200 to 250 degrees C. Good agreement between XRD and XPS analysis was obta ined in characterizing the film structures. The observed phenomena are discussed briefly. (C) 1998 Elsevier Science S.A. All rights reserved .