Room-temperature TiOx oxide diode for 1D1R resistance-switching memory
Resistive-switching behaviors in transition metal oxides, such as NiO and TiO2, have attracted great attention recently due to the potential for the next-generation nonvolatile memory applications [1, 2]. However, read disturbance due to the cross-talk among neighboring cells is a serious issue for the implementation of large memory array as shown in Fig. 1 [3]. Traditionally, a transistor can be added as a selection element in the memory cell, the so-called 1T1R (one transistor one resistor) cell, to prevent undesirable cross-talk, but at the expense of increasing cell size and high thermal-budget. Nevertheless, it is unfavorable in the high-density memory array where the unit cell size and the low-temperature three-dimensional stacking is of the concern. Recently, a compact 1D1R cell, which utilizes an oxide-based diode as the selection element to cut off the parasitic cross-talk, has been realized [4]. The ratifying pn junction formed by two different oxide layers, one n-type and one p-type, provides sufficient on-off ratio and current density, but the high turn-on voltage and high ideality factor are less than ideal. In this study, we demonstrate a high forward-current TiOx diode fabricated at room temperature by a very simple process. Finally, the switching behavior of the 1D1R cell will be discussed.