Epitaxial growth of Gd silicides prepared by channeled ion implantation

A continuous buried GdSi1.7 layer is formed by channelled implantation of 90 keV Gd ions into Si(111). In the case of (001) oriented silicon substrates, the silicide film is formed on the silicon surface. Its worse crystalline quality is due to the epitaxy occurring relative to all four(111)si planes resulting in a textured GdSi1.7 layer. Annealing at a temperature of greater than or equal to 850 degrees C for 30 min results in the presence of only the orthorhombic GdSi2 phase on the silicon surface for both (111) and (001) silicon substrates. However, the precipitates embedded in the silicon substrate are still hexagonal GdSi1.7. The phase transformation temperature is higher for (111) than for (001) silicon. (C) 1997 American Institute of Physics.