Fabrication and structure of epitaxial Er silicide films on (111) Si

Abstract
We prepared Er silicide films on (111) Si by (1) deposition of Er and contact reaction at 380 °C or (2) vacuum codeposition of Er and Si maintaining the flux ratio close to 1:2. Subsequent annealing at temperatures up to 900 °C yielded monocrystalline, continuous layers, whose properties were examined by means of low-energy electron diffraction, Auger spectroscopy (in situ) and (ex situ), x-ray and high-energy electron diffraction, and Rutherford backscattering. Method 2 was shown to give better results. The films had a hexagonal AlB2 structure with Si deficiency up to 20%, which is consistent with formerly published results on Si vacancy formation. We showed that the film structure had an additional periodicity of 15 Å along the 〈110〉 orientations of Si and of 6 Å along the 〈112〉 orientations of Si. We demonstrated a feasibility of Si reepitaxy on Er silicide deposited on (111) Si, thus fabricating a novel semiconductor/metal/semiconductor epitaxial heterostructure.