Nanoscale resistive switching in amorphous perovskite oxide (a-SrTiO3) memristors

Memristive devices are the precursors to high density nanoscale memories and the building blocks for neuromorphic computing. In this work, a unique room temperature synthesized perovskite oxide (amorphous SrTiO3: a-STO) thin film platform with engineered oxygen deficiencies is shown to realize high performance and scalable metal-oxide-metal (MIM) memristive arrays demonstrating excellent uniformity of the key resistive switching parameters. a-STO memristors exhibit nonvolatile bipolar resistive switching with significantly high (103-104) switching ratios, good endurance (>106I-V sweep cycles), and retention with less than 1% change in resistance over repeated 105 s long READ cycles. Nano-contact studies utilizing in situ electrical nanoindentation technique reveal nanoionics driven switching processes that rely on isolatedly controllable nano-switches uniformly distributed over the device area. Furthermore, in situ electrical nanoindentation studies on ultrathin a-STO/metal stacks highlight the impact of mechanical stress on the modulation of non-linear ionic transport mechanisms in perovskite oxides while confirming the ultimate scalability of these devices. These results highlight the promise of amorphous perovskite memristors for high performance CMOS/CMOL compatible memristive systems.