Study of atomic layer deposited ZrO2 and ZrO2/TiO2 films for resistive switching application



Thin ZrO2 films and ZrO2/TiO2 bilayers grown by atomic layer deposition (ALD) are integrated into metal–oxide–metal (MOM) structures for investigation of resistive switching (RS) properties. The films have different microstructure depending on the used ALD oxygen source and stacking sequence for the bilayers. Pt/ZrO2/Ti/Pt devices show unipolar RS for oxide thicknesses of 11–18 nm. The devices with O3 grown ZrO2 show higher yield in comparison to the ones with H2O processed oxide. The switching polarity of the Pt/ZrO2/Ti/Pt cells depends on the thickness of the Ti electrode layer. The increase of the Ti layer thickness leads to a change in switching polarity from unipolar to bipolar. The formation of ZrO2/TiO2 bilayers results in changes in the RS behavior of the MOM cells depending on the stacking sequence.