(Invited) ALD Grown Functional Oxide Layers for Nonvolatile Resistive Switching Memory Applications

Abstract

The significance of atomic layer deposition (ALD) for the growth of transition metal oxide thin films which are to be integrated into metal-oxide-metal structures for future nonvolatile resistive switching memory devices is illustrated. Focus is put to the requirements on transition metal oxide layers with respect to the control of morphology, structure, and defect state. For the representative example of ALD TiO2-x thin films grown from different titanium sources possibilities for a design of thin film properties by means of precise process control are exemplified. The success of this strategy is highlighted by the resistive switching behavior of 8 nm ALD TiO2-x thin films integrated into Pt/ TiO2-x/Ti/Pt cross point junctions of 100 nm x 100 nm lateral size by which it could be demonstrated that a stable SET operation in TiO2 films is possible for compliance currents of about 20 µA.