Nanoscale Resistive Switching in Amorphous Perovskite Oxide (a-SrTiO3) Memristors


  • M.B. and S.S. dedicate this work to the memory of Dr. K. Govindarajan


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.