Conduction and Low-Frequency Noise Analysis in $\hbox {Al}/\alpha \hbox {-TiO}_{X}/\hbox {Al}$ Bipolar Switching Resistance Random Access Memory Devices

We investigated the low-frequency noise (LFN) properties of the bipolar switching resistance random access memories (RRAMs) for the first time with amorphous TiO_x -based RRAM devices. The LFNs are proportional to 1/f for both high-resistance (HRS) and low-resistance states (LRS). The normalized noise in HRS is around an order of magnitude higher than that in LRS. The random telegraph noise (RTN) is observed only in HRS, which represents that the dominant trap causing the RTN becomes electrically inactive by being filled with electrons in LRS. The voltage dependence S_i/I² of shows that the noise can be used to elucidate the operation mechanism of RRAM devices.