Conduction and stability of holmium titanium oxide thin films grown by atomic layer deposition

© 2015 Elsevier B.V. All rights reserved. Holmium titanium oxide (HoTiO<inf>x</inf>) thin films of variable chemical composition grown by atomic layer deposition are studied in order to assess their suitability as dielectric materials in metal-insulator-metal electronic devices. The correlation between thermal and electrical stabilities as well as the potential usefulness of HoTiO<inf>x</inf> as a resistive switching oxide are also explored. It is shown that the layer thickness and the relative holmium content play important roles in the switching behavior of the devices. Cycled current-voltage measurements showed that the resistive switching is bipolar with a resistance window of up to five orders of magnitude. In addition, it is demonstrated that the post-breakdown current-voltage characteristics in HoTiO<inf>x</inf> are well described by a power-law model in a wide voltage and current range which extends from the soft to the hard breakdown regimes.