Oriented Tin-Doped Indium Oxide Films on Preferred Oriented Polycrystalline ZnO Films

Abstract

-oriented tin-doped indium oxide (ITO) films were deposited by rf magnetron sputtering on ZnO-coated glass substrates (ZnO/glass). The ZnO underlayers were also deposited by rf magnetron sputtering and have been known to exhibit preferred orientation in a wide range of deposition conditions. The X-ray diffraction profiles of the ITO films deposited on the ZnO/glass showed predominant orientation without any differently oriented crystallites, whereas the ITO films deposited on bare glass substrates (ITO/glass) under the same deposition conditions showed -preferred orientation with small areas of several other orientations. A mechanism of the heteroepitaxial growth of In₂O₃(111)|| ZnO(001) was explained by comparing the atomic configurations of oxygen between the oxygen mostly dense-packed planes of In₂O₃ and ZnO parallel to In₂O₃(111) and ZnO(001) planes, respectively. Sn concentrations and lattice constants of the -oriented films (ITO/ZnO/glass) were found to be greater than those of preferred oriented films (ITO/glass) in spite of the fact that the target and deposition conditions were the same, which could be associated with the electrical properties of the films.