Strain measurements of semiconductor multilayers by ion channeling, High Resolution XRD and Raman Spectroscopy

The ion-beam channeling technique has been used, along with other characterization techniques, to characterize the epilayer and interface of In0.1Ga0.9As/GaAs superlattice structures grown by Organo Metallic Vapour Phase Epitaxy (OMVPE). Strain produced n the epilayer and at the interface due to the lattice mismatch between In0.1Ga0.9As and GaAs substrate can be directly measured by carrying out ion-channeling in the off-normal channeling axes. The energy of the probe beam plays a very important role in the determination of strain, the critical angle for channeling being directly related with it. At low incident energies, the critical angle is comparable to the angular misalignment of the axes, giving rise to ambiguous measurements in the strain values. We discuss here the Beam Steering effect occurring at low energy channeling and compare the channeling results with High Resolution XRD and Raman Spectroscopy.