Computer simulation of channeling in strained-layer superlattices

In this paper a computer simulation program for the calculation of channeling is described. The program is based on the binary collision model and permits analysis of fundamental physical processes of channeling as well as of backscattering channeling spectra for single crystals, multielemental and multilayered strained structures. The special features of the medium ion energy region and the electrostatic energy analysis are taken into account. The calculated channeling spectra of 300 keV protons for the <110>→(100) and <110>→(110) axial-to-planar channeling transition in silicon and the analysis of the ion trajectories explain the dramatically changed oscillations of the RBS planar channeling yield at resonance dechanneling conditions observed experimentally. Furthermore, the calculations verify the up to threefold increase in width of the channeling surface peak as measured in the analysed transition from axial-to-planar channeling. For a strained-layer SiGe/Si system, the energy and thickness dependence of the steering effect are systematically analysed. The application of the program to the quantitative strain determination in strained-layer superlattices (SLSs) by dechanneling measurements is demonstrated. (orig.)