Structural properties of ultra-low-energy ion-implanted silicon studied by combined X-ray scattering methods

The use of a combination of X-ray scattering techniques for the complete characterization of ultra-low-energy (E < 5 keV) implanted Si is discussed. Grazing incidence diffuse X-ray scattering (GI-DXS) reveals the properties of the defects confined within thin crystalline layers with depth resolution. Due to the weak diffuse intensity arising from such defects, the high brilliance of synchrotron radiation is required. GI-DXS proved to be particularly well suited for the investigation of the so-called `end-of-range' defects. In a complementary way, X-ray diffraction (XRD) in the vicinity of the 004 Bragg reflection is sensitive to the distribution of the strain in the Si lattice in the direction perpendicular to the sample surface. The structural characterization is complemented by the electron density profile of the near-surface amorphous region provided by specular reflectivity (SR). It will be shown that only by merging the results obtained with GI-DXS, XRD and SR, is it possible to obtain the detailed structural characterization of the implanted Si samples.