Fabrication of periodically polarity-inverted ZnO structures on (0001) Al2O3

Two-dimensional periodically polarity-inverted (PPI) ZnO structures were fabricated on (0001) Al2O3 substrates using plasma assisted molecular beam epitaxy. Holographic lithography was carried out for the realization of nanometer-scale patterns of CrN which was obtained by nitridation of Cr metal. The PPI ZnO structures consisted of Zn-polar regions grown on CrN and O-polar regions grown on Zn-terminated AlN/Al2O3. The periodical polarity inversion was confirmed by voltage-piezo response curves and contrast in the piezo response microscopy images. A diffraction pattern of the fabricated PPI ZnO sample was observed when a He-Ne laser beam was incident on the sample surface.