Complementary resistive switching behaviors evolved from bipolar TiN/HfO2/Pt device

Abstract

In this letter, the dynamic evolution of TiN/HfO2/Pt device from bipolar resistive switching (BRS) to complementary resistive switching (CRS) was reported. The device exhibits the uniform BRS with long retention, good endurance, and self-compliance characteristics after the asymmetric two-step electroforming. However, BRS of the device eventually transforms to CRS after the transitional processes through controlling the compliance current. Meanwhile, the effective barrier height rises up accordingly as the device evolves from BRS to CRS. These superior resistive switching performances of TiN/HfO2/Pt device here can be elucidated in views of evolution of asymmetric filament. This work confirms the intimate correlation and discrepancy between BRS and CRS, and also indicates the potential application of TiN/HfO2/Pt device for future ultra-dense resistive random access memory.

Control of Switching Modes and Conductance Quantization in Oxygen Engineered HfOx based Memristive Devices

“…On lowering of the operating voltage compared to cf8 ‐BRS, we observe a transition to complementary resistive switching, as shown in Figure e. This CRS mode was observed in the narrow regime of −1.2 V in the negative polarity and +1.1 V in the positive polarity, in agreement with other similar results, where a f8 type bipolar switching was observed simultaneously . CRS was attributed by Brivio et al to the presence of an oxidized TiON layer at the interface of HfO 2 and TiN generated during deposition.…”

“…CRS was attributed by Brivio et al to the presence of an oxidized TiON layer at the interface of HfO 2 and TiN generated during deposition. However, Chen et al activated the CRS operation using in devices where TiN was used as a top electrode, thus avoiding its oxidation during deposition . Any further increase in the positive bias voltage was found to lead to a deep reset behavior, thus, crossing over to a standard cf8 type BRS, as described before.…”

“…Adding to the more frequently observed cf8 ‐BRS mode, a lower‐bias voltage f8 ‐BRS mode (reset process with TiN as anode) with lower resistance ratios (≤10) was also observed in similar devices . This f8 operation was further found to coexist with a complementary resistive switching (CRS) operation . Despite these various observations, the nature of partial coexistence of various switching modes and the conditions for the occurrence of quantization remain to be understood.…”

“…In order to achieve this goal, we have investigated as a model system a prototypical HfO 2 based RRAM device using Pt and TiN electrodes, which has been reported to exhibit reliable switching in several publications . In addition, this device type is particularly interesting due to multiple coexisting switching modes and polarities, as well as a large possible resistance window of operation, making it promising as multibit synaptic devices in neuromorphic computing . In the Pt/HfO 2 /TiN device configuration, with applied bias to Pt electrode, a stable cf8 ‐BRS mode has been most often reported.…”

Evaluating extrinsic origin of frequency dispersion of measured capacitance in high‐k mixed stacks

“…The creation of additional charges and trapping centers at the interface between the oxide and the gate should also be considered when revealing the real capacitance of the structure [45][46][47]. In this case also, the effect of the metal gate should be taken into account [48][49][50].…”