The formation of yttrium silicides in implanted (170keV Y+, 4 x 1017/cm2) Si(111) was investigated by means of transmission electron microscopy, X-ray diffraction and Auger electron spectroscopy. A continuous buried YSi2 layer, which was about 35nm in thickness, was found beneath a 30nm-thick polycrystalline layer. The preferential growth of YSi2, with [001]YSi2||[111]Si, was found to predominate. A high density of twins and stacking faults was distributed in the layer beneath the silicide layer. In annealed (800C, 30s) samples, a continuous silicide layer which was about 100nm thick formed at the surface. The YSi2 was found to agglomerate in samples which were annealed at 1000 to 1100C for 30s. A high density of defects remained below the original silicide/Si interface. The silicide maintained its epitaxial relationship with respect to the substrate. No sign of vacancy ordering was detected in the diffraction patterns of as-implanted and annealed samples.

S.Jin, J.H.Lin, L.J.Chen, W.D.Shi, Z.Zhang: Nuclear Instruments and Methods in Physics Research B, 1995, 96[1-2], 347-51