Etching-dependent reproducible memory switching in vertical SiO2 structures

TL;DR

This study investigates how different etching methods affect the reproducibility of memory switching in vertical SiO2 structures, revealing filamentary conduction as the key mechanism and demonstrating high ON/OFF ratios.

Contribution

It introduces etching-dependent fabrication of vertical SiO2 memory devices and identifies filamentary conduction as the primary switching mechanism.

Findings

Both dry and wet etched structures show voltage-controlled memory switching.

High ON/OFF ratios exceeding 10^4 were achieved.

Filamentary conduction explains the switching behavior.

Abstract

Vertical structures of SiO$_{2}$ sandwiched between a top tungsten electrode and conducting non-metal substrate were fabricated by dry and wet etching methods. Both structures exhibit similar voltage-controlled memory behaviors, in which short voltage pulses (1 $\mu$s) can switch the devices between high- and low-impedance states. Through the comparison of current-voltage characteristics in structures made by different methods, filamentary conduction at the etched oxide edges is most consistent with the results, providing insights into similar behaviors in metal/SiO/metal systems. High ON/OFF ratios of over 10$^{4}$ were demonstrated.