Polycrystalline silicon-germanium films prepared by aluminum-induced crystallization

The Si(1-x)Ge(x) thin films were deposited on Al-coated glass and single-crystal Si substrates by traditional plasma-enhanced chemical vapor deposition with the mixture of SiH(4), GeH(4), and Ar at a low temperature of 300 degrees C. The structure of the films was characterized by X-ray diffraction, Raman spectra, field-effect scanning electron microscopy, and atomic force microscopy. It showed that the Al layer was a very effective crystallization precursor for preparing the Si(1-x)Ge(x) thin films. The polycrystalline Si(1-x)Ge(x) thin films were the easiest to be formed when x = 0.06. Moreover, the (111) interplanar spacing values (d(111)) of the stress-free poly-Si(1-x)Ge(x) thin films, with a lower concentration of crystallographic defects, were in accord with Vegard's law. The grain size was sensitive to the annealing temperature and the Ge content. And, there was no surface roughening in the aluminum-induced crystallization poly-Si(1-x)Ge(x) (0 < x < 0.2). (C) 2008 The Electrochemical Society.