Near-Amorphous Alloy Thin Films by Co-Sputtering Deposition
Four alloy thin films were deposited on Si(100) by co-sputtering of various metals to investigate the formation of near-amorphous structure which may lead to featureless surface morphology and boundary-free structure. These thin films, Nb-Cr, Ta-Cr, Ti-Nb, and Zr-Cr, were examined using XRD SEM, and TEM. It is found that the forming ranges of near-amorphous thin films by co-sputtering are related to the difference in atomic size of the paired metals as well as their heat of mixing. Accordingly, Zr-Cr has the widest concentration range to form the near-amorphous structure. The addition of nitrogen during deposition can further enhance amorphization and reduce the surface roughness, until nitride phases are formed.
M. Gupta and Christina Y.H. Lim
J.H. Hsieh et al., "Near-Amorphous Alloy Thin Films by Co-Sputtering Deposition", Journal of Metastable and Nanocrystalline Materials, Vol. 23, pp. 211-214, 2005