This results in the formation of multiple oxygen filaments (Figure 7c). Under RESET operation of the NF devices, both Joule heating and O2−migration from the W BE/high-κx interface will lead to the oxidation of the conducting filament (Figure 7d). Overshoot RESET current is also observed (Figure 8). The maximum I RESET of the devices containing AlOx, GdOx, HfOx, and TaOx switching materials were 616,
1,180, 1,628, and 2,741 μA, respectively, for NF devices, and 409, 543, 276, and 684 μA, respectively, for the PF devices (Figure 8a,b,c,d). The RESET current of NF devices is higher in all cases than the PF devices probably because of higher current overshoot in the NF devices. Current overshoot degrades the switching material because selleck chemicals llc uncontrolled oxygen vacancy filaments form. For the NF devices, the multifilaments can be formed due to oxygen ion migration ; however, the filaments are ruptured by thermal effect under RESET operation, i.e., the thermal Selleck AZD8186 dissolution of oxygen vacancy filaments may result the uncontrolled filaments to break as well
as the SET operation will not be controlled in consequence. The thermal dissolution of conducting filaments under RESET operation on NiOx-based resistive https://www.selleckchem.com/products/rsl3.html switching memories was also reported by Ielmini et al.  and Long et al. [40, 41]. In contrast, the damage is negligible in the PF devices because of the presence of an electrically formed interfacial layer at the TE/high-κ interface. The filament
diameter is readily controlled in the PF devices because of the electrically formed interface. This kind of asymmetric resistive memory stack will help to optimize resistive switching and device performance. Figure 6 Fitted I-V characteristics of PF and NF devices with IrO x /TaO x /W structure. (a) LRS of NF devices fitted ohmic behavior. (b) HRS for the NF devices were consistent with Schottky behavior. (c) Both LRS and HRS of the PF devices show a TC-SCLC transport mechanism. Figure 7 Resistive switching mechanism of the mafosfamide PF and NF devices. PF and NF devices under (a, c) SET and (b, d) RESET operations. Figure 8 RESET phenomena for the PF and NF devices. RESET currents of NF and PF devices containing (a) AlOx, (b) GdOx, (c) HfOx, and (d) TaOx switching materials with an IrOx/high-κx/W structure. High-density memory devices are required for future applications. Resistive memory devices with cross-point architecture show promise to achieve high-density memory. Therefore, we fabricated the resistive memory stacks of IrOx/high-κx/W with cross-point structure (S2). Figure 9 shows the typical I-V curves of 1,000 consecutive dc switching cycles obtained for an IrOx/AlOx/W stack. The applied voltage sweep direction is indicated by arrows marked 1 to 4.