Channeling contrast microscopy of epitaxial lateral overgrowth of ZnO/GaN films

Rutherford Backscattering Spectrometry (RBS) is a powerful tool for the quantitative characterization of the depth profile and the crystallinity of such structures, and channeling contrast microscopy (CCM), which employs a focused ion beam in order to obtain laterally resolved channeling yield data, is ideally suited to determine micro structural characteristics, (e.g. defect densities, tilts in lattice planes, strain) of such samples. Here we report results from proton channeling contrast measurements of laterally overgrown ZnO thin films. The results show that high crystal quality ZnO films can be grown using the ELO method. Cross-sectional scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and CCM are used to study the morphology and microstructure of the ELO ZnO films.