1 Study of the Influence of the Dielectric Composition of Al/Ti/ZrO2:Al2O3/TiN/Si/Al Structures on the Resistive Switching Behavior for Memory Applications H. Castán a , S. Dueñas a , K. Kukli b,c , M. Kemell b , M. Ritala b , and M. Leskelä b a Department of Electronics, University of Valladolid, Valladolid, Spain b Department of Chemistry, University of Helsinki, Helsinki, Finland c Institute of Physics, University of Tartu, Tartu, Estonia correspondent author email: helena@ele.uva.es The memory behavior of Al/Ti/ZrO2:Al2O3/TiN/Si/Al devices is investigated in this work. They are adequate to be used as resistive switching memories, with two clearly different states. Besides, intermediate states are also accessible in a controllable manner. The electrical characterization in terms of admittance parameters provides relevant complementary information. The cation ratio influences the memory maps and can be changed to obtain specifically sized shape of the maps. Introduction Nowadays both volatile and non-volatile memories are under a high development pressure in the industrial context. Besides the dominant solid-state memory technologies, such as DRAM and flash, non-volatile random access resistive memories (RRAM) are considered adequate candidates to complement the memory landscape [1, 2]. In spite of the interest, no consensus has been reached yet about the selection of appropriate materials for fabrication [3, 4]. The aim of this work is to deepen the knowledge on the usefulness of transition metal oxides in this field, and specifically to explore the improvements on the memory behavior of metal/ZrO2/metal structures by stabilizing metastable phases of ZrO2 by doping or nanolaminating the dielectric films with small and controlled amounts of Al2O3. The effects of materials structure and composition on memory window, stability and robustness, as well as comparative small-signal response are reported in this study. Experimental ZrO2:Al2O3 films were grown on highly-doped conductive Si <100> substrates covered by 10 nm thick TiN films by means of atomic layer deposition (ALD) at 350 ºC. The reactor was a flow-type hot-wall F120 (ASM Microchemistry Ltd.). The precursors were AlCl3 (99%, Acros Organics), ZrCl4 (99.9%, Aldrich), and O3. For electrical measurements, Al/Ti/ZrO2:Al2O3/TiN/Si/Al capacitor stacks were fabricated. Double-layer 110 nm-Al / 50 nm-Ti top electrodes were electron-beam evaporated. The electrode area used in the measurements was 0.204 mm 2 . The bottom electrode was provided by evaporating 100- 120 nm thick Al layer on HF-etched Si. A similar sample based on HfO2:Al2O3 was also deposited for comparison, deposited at 350 ºC and by using HfCl4 (99.9%, Strem) as precursor. All samples are listed in Table I.