A backscattering ion channeling study of the lattice site location of the constituents of two systems

Abstract

Backscattering ion channeling measurements were performed to determine the lattice site location of the constituents of two systems. For (GaSb) 1_x(Ge2)x spectra were obtained at a set of incident beam orientations along an angular scan through the [110] direction and nearly parallel to the [110) plane. The asymmetry in the backseattering yield from the antimony in the near surface region is used to observe a structural phase transition in the alloy from the zinc blende structure to a diamond structure. In the second system the extent of antimony segregation to the [111] silicon - silicon dioxide interface was first determined. Channeling scans were made through the [111], [110] and [121] directions of thin silicon crystals with a silicon dioxide layer at the rear surface. By comparing the form of the channeling yield scan for antimony that had been segregated to the interface with the signal from the silicon crystal itself it was possible to deduce the projected position of the antimony in each direction. The antimony was found to occupy a silicon substitutional site. For both of these systems computer simulations of the channeling process were carried out in order to internet the data quantitatively.