Effect of oxygen diffusion into TiN on resistance switching characteristics of ZrO2 films with annealing temperatures

In this study, the effects of annealing temperature on both physical and resistive switching properties of ZrO₂ films were investigated. XRD showed the increase of the monoclinic phase in the as-grown tetragonal ZrO₂ with annealing above 450°C. The ZrO₂ films exhibited the unipolar and the bipolar switching behaviors in Pt/ZrO₂/TiN MIM structure. The HRS resistance in unipolar switching behavior was reduced with increasing annealing temperature. On the contrary, The HRS resistance in bipolar switching behavior was increased. XPS showed the increase of metallic Zr in annealed ZrO₂ films that could cause the reduction of HRS resistance in unipolar resistance switching of ZrO₂. SIMS spectra confirmed the enlargement of interfacial TiO_xN_y layer in TiN bottom electrode with increasing the annealing temperature. The enlargement of interfacial TiO_xN_y layer was expected to cause an increase of HRS resistance because the larger amount of mobile oxygen ions in inter-facial TiO_xN_y layer was possible to migrate to ZrO_2-x films.