Epitaxial ternary Er 0.5Y 0.5Si 1.7 silicide layers formed by channeled ion beam synthesis

Abstract

The ternary silicide, Er 0.5Y 0.5Si 1.7 has been produced by channeled ion beam synthesis (CIBS) in a Si(1 1 1) substrate. The properties of the material have been compared with those of the binary silicides (i.e. ErSi 1.7 and YSi 1.7) produced by the same method. Analysis was carried out using Rutherford backscattering (RBS) and X-ray diffraction (XRD). The study revealed that the layer produced is of good crystalline quality, and is indeed composed of the Er 0.5Y 0.5Si 1.7 ternary silicide as opposed to a mixture of the two binaries. It is epitaxial with respect to the Si substrate and possesses the same hexagonal (AlB 2) structure exhibited by both binary silicides. The azimuthal orientation with respect to the substrate is Er 0.5Y 0.5Si 1.7[0 0 0 1]//Si[1 1 1] and Er 0.5Y 0.5Si 1.7{1 1 2 ̄ 0}//Si{1 1 0}. The epilayer was found to be elastically strained with the perpendicular strain=−0.67% and the parallel strain=+0.34% similar to the values found for the Er and Y silicides.