Electrical properties of heteroepitaxial grown tin-doped indium oxide films

Abstract

Oriented thin-film tin-doped indium oxide (ITO) was heteroepitaxially grown on optically polished (100) or (111) planes of single-crystalline yttria-stabilized zirconia (YSZ) substrates using e-beam evaporation or dc magnetron sputtering techniques. Pole figure x-ray diffraction analyses revealed that the heteroepitaxial relations were (001)ITO∥(001)YSZ, [100]ITO∥[100]YSZ, and (111)ITO∥(111)YSZ, [110]ITO∥[110]YSZ, respectively. X-ray rocking curve analyses and Rutherford backscattering spectrometry revealed that the e-beam evaporated heteroepitaxial ITO films had much higher crystallinity than the one deposited by dc magnetron sputtering. Both carrier density and Hall mobility of the e-beam evaporated heteroepitaxial films showed steady increases in a wide temperature range, which could be interpreted in terms of the increasing Sn-doping efficiency caused by the improvement of the crystallinity of In2O3 host lattice, and hence the decreasing Sn-based neutral scattering centers.