Figure 3 shows

the AFM images of 20-nm-thick Lu2O3 film. The rms value obtained by AFM observation was 1.82 nm. The lower surface roughness may result in better uniformity and higher yield of the fabricated memory devices. Figure 1 XRD micrographs of amorphous Lu 2 O 3 thin film sputtered on flexible ITO/PET substrate. Figure 2 XPS line-shape analyses. (a) O 1 s. (b) Lu 4d spectra for Lu2O3 thin film on ITO/PET substrate. Figure 3 AFM image of Lu 2 O 3 thin film on flexible SBI-0206965 in vitro ITO/PET substrate. In order to investigate the memory performance of the flexible Ru/Lu2O3/ITO ReRAM cell, the RS characteristics were analyzed. A high bias voltage with predefined current compliance (I CC) of 100 μA was applied to the pristine memory cell to initiate the RS into the Lu2O3 thin film, as shown in Figure 4a. I CC is required to protect the device from hard breakdown. During this initial bias sweeping, a sudden abrupt decrease in oxide conductance was observed, which is known as soft breakdown or Belnacasan chemical structure electroforming

process. A nanomorphological change into the oxide layer is assumed due to the introduction of a high oxygen vacancy density of the oxide thin films [25]. After the electroforming process, the memory device switches to low-resistance state (LRS). To change the resistance state of the memory device, a sufficient positive bias of certain value (V reset) was applied and the devices transform to high-resistance oxyclozanide state (HRS), as shown in Figure 4b. In contrast, an application of negative bias results in a transition from HRS to LRS at certain set voltage (V set) and this effect is reproducible over several hundreds of voltage 10058-F4 order sweeping cycles. As can be seen that the Ru/Lu2O3/ITO ReRAM cell can be switched between two distinguished resistance state (HRS to LRS and vice versa), at a very low voltage of approximately 0.8 V (100 μA set current) and approximately 1.2 V (<1 mA reset current) for set and reset operations, respectively. The lower switching

voltage is believed due to the low power hopping conduction via oxide defects [7]. In order to realize the current conduction mechanism into the Lu2O3 thin film, both HRS and LRS current–voltage (I-V) characteristics at different temperature were analyzed. Figure 4 Analysis of the RS characteristics of Ru/Lu 2 O 3 /ITO ReRAM device. (a) The electroforming process of the Ru/Lu2O3/ITO ReRAM device with current compliance of 100 μA. Shaded area shows the typical RS behavior after electroforming process. (b) Enlarged view of the shaded region showing promising RS characteristics of the Ru/Lu2O3/ITO ReRAM device. Figure 5 shows the resistance variation of the memory device at different resistance states at different temperatures ranging from 303 to 353 K. In HRS, the resistance value decreases as the temperature increase to 353 K.