Comprehensive Rutherford backscattering and channeling study of ion-beam-synthesized ErSi1.7 layers

Heteroepitaxial ErSi1.7 layers with excellent crystallinity (chi(min) of Er is 1.5%) have been prepared by high-dose 90 keV Er implantation into a Si(111) substrate using channeled implantation. Such an ErSi1.7/Si system offers a rare opportunity to study comprehensively the structure, orientation, and strain using Rutherford backscattering spectrometry and channeling analysis. We found that the minimum yield and width of the [0001] dip of the Er atoms are quite different from that of the Si atoms in the silicide layer. It is confirmed that the azimuthal orientation of the hexagonal ErSi1.7 layer to the cubic Si substrate is ErSi1.7 [0001] parallel to Si[111] and ErSi1.7 {11 (2) over bar 0} parallel to Si {110}, and that the epilayer is compressively strained. Besides, by using the angular scan and image scan, we reveal that the dips of the {10 (1) over bar 0} family are missing for the Si atoms in the epilayer but do exist for the Er atoms in the same epilayer. The reason for this drastic difference is explained by the separate {10 (1) over bar 0} planes and the different steering potential of the Si and Er atoms in ErSi1.7. (C) 1996 American Institute of Physics.