Fig. 1
From: Multi-level resistive switching in hafnium-oxide-based devices for neuromorphic computing
Reported device sizes and positive and negative switching voltages for hafnium-oxide-based multi-level RS. a Number of reported devices vs. device size. If different device sizes were reported in a publication, we included the smallest one in the figure. The arrow points out the most common device size. Inset: Illustration of gradual and abrupt switching. Red and purple, schematic: forming and subsequent switching with a positive compliance current as typically observed for filamentary RS. Blue: gradual non-filamentary switching from a system like [36]. b Switching voltages after forming (where necessary). Crosses correspond to individual reports, bubbles to multiple identical values from different reports, and the red line indicates symmetry between positive and negative switching voltages. The values in the figure correspond to the voltages applied to devices during the IV sweeping. Inset: Illustration of probes (dark gray) and probe pads (light gray) required for high-speed electrical measurements such as for measuring the ultimate device switching speed or switching power consumption