Resistive switching properties of a polycrystalline TiO₂ memory cell with a tungsten nitride (WN) buffer layer inserted

Resistive switching properties were investigated in a polycrystalline TiO₂ film with a tungsten nitride (WN) barrier layer sandwiched between the Pt electrodes. DC voltage-current measurements were done to observe the switching properties of the low- and the high-resistance states. The TiO₂ memory cell was also studied in terms of the electrical pulse parameter dependence of the Set/Reset switching process. The dc voltage-current characteristics of the TiO₂ memory cell with a WN barrier layer demonstrated enhanced switching compared to those of the memory cell without WN barrier layers. In addition, stable resistance switching in the cell with WN inserted was repetitively observed to be a strong function of the amplitude and the width of the voltage pulse. This stable switching property is expected to originate from the decrease in the number of oxygen vacancies at the interfaces between the Pt electrode and the TiO₂ layer due to the inserted WN buffer layer.