Surface Structure of ZnO Single Crystals Analysed by Ion Scattering Spectroscopy

A ZnO crystal of wurtzite-type structure has polar surfaces of (0001) and (0001), which are terminated by Zn and O ions, respectively. Observation conducted by atomic force microscopy showed that step/terrace structures were formed on the (0001) and (0001) surfaces, whose step height was predominantly half of lattice parameter, c 0 . The ionic arrangement of the surfaces was determined by coaxial impact-collision ion scattering spectroscopy (CAICISS); the CAICISS spectra had a periodicity of 60° for azimuth angle dependence. From the analyses of CAICISS spectra it was shown that the (0001) and (0001) surfaces had a single dangling bond, and no ionic distortion occurred.