Lattice Spacings of Fe Films Deposited by Facing Targets Type Sputtering

Abstract

Pure Fe films, deposited on various substrates under several Ar gas pressures, have been investigated by means of X-ray and electron diffraction, electron microscopy with a heating stage, and electron microprobe analysis. The apparent lattice spacing of Fe films decrease with increasing Ar gas pressure regardless of substrate materials and show a close relation to the film stresses. The films deposited at low Ar gas pressures have compressive stresses. After being annealed, the films have smaller lattice spacings than before. Correspondingly the half-value width of X-ray diffraction lines becomes narrow increasing annealing temperature. In situ observations by electron microscopy on the heating process of Fe films showed that the recrystallization process was able to take place even at 473 K. No significant evidence of incorporation of Ar atoms into Fe films was obtained. The present results suggest that the lattice expansion observed in the deposited Fe films can be ascribed to energetic particle bombardment, i.e., atomic shot-peening action rather than to the incorporation of Ar atoms into Fe films.