Two‐ and Three‐Terminal Resistive Switches: Nanometer‐Scale Memristors and Memistors

Abstract

The logical relationship between two previously defined “memory resistors” is revealed by constructing and experimentally demonstrating a three‐terminal memistor equivalent circuit using two two‐terminal memristors. A technique is then presented, using nanoimprint lithography in combination with angle evaporation, to fabricate a single nanoscale device with a footprint of 4F2, where F is the minimum lithographic feature size, that can be operated as either a two‐terminal lateral memristor or a three‐terminal memistor inside a crossbar structure. These devices exhibit repeatable bipolar nonvolatile switching behavior with up to 103 ON/OFF conductance ratios, as well as the desired three‐terminal behavior.

Current-induced electrical self-oscillations across out-of-plane threshold switches based on VO2 layers integrated in crossbars geometry

“…23 The term accounts also for the volatility of the resistive switching in MIT materials, as opposed to the non-volatile, permanent effects induced by electrical switching in memristive systems. 24 First observations of threshold switching in VO 2 bulk materials show that the E-MIT is described by an S-shaped current-voltage characteristic of the devices, characterized by a current controlled negative differential resistance (CC-NDR). [25][26][27][28] Under a specific electrical excitation, this CC-NDR effect underlies the onset of spontaneous electrical oscillations across two-terminal devices integrating bulk VO 2 , 26-28 with oscillation frequencies in the kHz range.…”

Nonvolatile three-terminal operation based on oxygen vacancy drift in a Pt/Ta2O5−x/Pt, Pt structure

“…Oxygen vacancy drift has also been used to achieve three-terminal memristive operations using TiO 2 . 27 In the demonstration, ON/OFF ratio up to three orders of magnitude was achieved.…”

Copper atomic-scale transistors

“…While two-terminal devices are able to constitute a completely new type of logic circuits as demonstrated by crossbar circuits [9], three-terminal devices can potentially be applied as logic operation devices that can fully utilize semiconductor circuit technology. Switching mechanisms such as valence-change memory effect, thermochemical memory effect, and electrochemical metallization effect have been previously exploited for three-terminal devices in solids [10–17]. But the performance of the solid resistive-switching three-terminal devices has to be improved in terms of switching rate, endurance and retention.…”