AVS 55th International Symposium & Exhibition | |
Thin Film | Thursday Sessions |
Session TF-ThM |
Session: | Evaporation, Pulsed Laser Deposition, and Molecular Beam Epitaxy |
Presenter: | D.I. Filoti, University of New Hampshire |
Authors: | D.I. Filoti, University of New Hampshire A.M. Brown, University of New Hampshire D. Carlson, University of New Hampshire J.M.E. Harper, University of New Hampshire |
Correspondent: | Click to Email |
We show that the evolution of metal fiber texture in sputtered metal-insulator composite thin films depends strongly on the composition through the presence of second-phase particles that interrupt normal metal grain growth. Using x-ray diffraction pole figures, we measured the strength of the Au(111) fiber texture as a function of composition in the Au-SiO2 system, which phase segregates during deposition. For very low SiO2 volume fractions less than 0.05, the Au has low resistivity and a strong (111) fiber texture similar to that of pure Au. For higher SiO2 volume fractions up to 0.3, the strength of the fiber texture decreases rapidly with increasing volume fraction of SiO2 second-phase particles, and the resistivity increases. For SiO2 volume fractions greater than 0.3, the fiber texture is lost as the Au becomes discontinuous and the microstructure changes to randomly oriented Au islands within an insulating matrix of SiO2, confirmed by resistivity and transmission electron microscopy measurements. We show that the rapid decrease in Au(111) fiber texture strength correlates with a reduction in Au grain size caused by Zener pinning of Au grains by second-phase SiO2 particles. Grain boundary pinning by second-phase particles prevents the development of (111) fiber texture that usually occurs during normal grain growth. The result is a more rapid loss of fiber texture as a function of composition than can be explained only by the decreasing Au volume fraction.