Influence of temperature on the epitaxial growth of In2O3 thin films on Y-ZrO2(1Â 1Â 1)

The influence of the substrate temperature on the epitaxial growth of In2O3 on Y-stabilized ZrO2(1 1 1) by oxygen plasma assisted molecular beam epitaxy has been investigated over a range between 550 and 860 °C. In all cases the films grow with (1 1 1) planes of the epilayer parallel to those of the substrate. Films grown at low temperature (T<650 °C) are characterised by a granular but continuous morphology. The high density of grain boundaries in these films may act as electron scattering centres, thus giving rise to low carrier mobility. For substrate temperatures above 700 °C, the films broke up into loosely connected mesa with serrated edges. The mesa had typical lateral dimensions of order 2-5 μm and exhibited atomically flat surface. X-ray diffraction shows that the change in film morphology releases strain. The effects of high temperature annealing on the properties of films deposited at low temperatures was also studied.