Flicker Noise Behavior in Resistive Memory Devices With Double-Layered Transition Metal Oxide

Characteristics of flicker (or 1/f) noise have been investigated in resistive-switching random access memory (RRAM) devices with TiN/Ti/TiO_x/HfO_x/TiN double-layered (DL) metal oxide structure. In DL-RRAMs, no significant difference is found in the normalized current noise power spectral densities of the high- and low-resistance states, unlike RRAMs with the TiN/Ti/TiO_x/ TiN SL structure. Based on comparative analysis, we demonstrate that the dominant 1/f noise source of DL-RRAM is located near the TiO_x/HfO_x and HfO_x/TiN interfaces, and the origin of 1/f noise is modeled to be the mobility fluctuation. A unique measurement method, which completely breaks down the HfO_x layer only, was employed for a systematic analysis of RRAMs with three different structures.