Ion-channeling studies of epitaxial layers

Depth and temperature dependences of ion channeling were used to characterize 1–4-μm Si layers on spinel substrates (Al2O3 · MgO). Profiles of the density of crystal imperfections in the Si layers have been calculated from the channeling spectra. The imperfections are greatest near the interface, and the crystalline quality improves significantly with increasing distance from the interface. This technique is particularly applicable to heteroepitaxial layers containing high densities of crystal imperfections and can be used to monitor the relative influence of growth parameters on the crystalline quality of the layers.