Relationship Between Conduction Mechanism and Low-Frequency Noise in Polycrystalline- $\hbox{TiO}_{x}$-Based Resistive-Switching Memory Devices

Low-frequency noise (LFN) characteristics have been studied in polycrystalline- TiO
_x
-based resistive random access memories (RRAMs). LFNs are proportional to 1/
f
in high-resistance state (HRS), but those in low-resistance state (LRS) are proportional to 1/
f
only in less than ~100 Hz. The normalized noise power in HRS is around three orders of magnitude higher than that in LRS. Bias dependence of 1/
f
noise shows that the current conduction mechanisms from noise measurements are consistent with those from the current-voltage relationships in TiO
_x
-based unipolar RRAM devices.