In Situ Imaging of the Conducting Filament in a Silicon Oxide Resistive Switch

TL;DR

This study uses in situ transmission electron microscopy to directly observe the formation, evolution, and switching mechanisms of conducting filaments in silicon oxide resistive switches, revealing silicon nanocrystals' role in conduction.

Contribution

It provides the first real-time imaging of filament formation and evolution in silicon oxide resistive switches, uncovering the role of silicon nanocrystals and their structural variations.

Findings

Silicon nanocrystals form during electroforming.

Filament growth and shrinkage are linked to electrical stimuli.

Insights into electrical breakdown in silicon oxide layers.

Abstract

The nature of the conducting filaments in many resistive switching systems has been elusive. Through in situ transmission electron microscopy, we image the real-time formation and evolution of the filament in a silicon oxide resistive switch. The electroforming process is revealed to involve the local enrichment of silicon from the silicon oxide matrix. Semi-metallic silicon nanocrystals with structural variations from the conventional diamond cubic form of silicon are observed, which likely accounts for the conduction in the filament. The growth and shrinkage of the silicon nanocrystals in response to different electrical stimuli show energetically viable transition processes in the silicon forms, offering evidence to the switching mechanism. The study here also provides insights into the electrical breakdown process in silicon oxide layers, which are ubiquitous in a host of electronic devices.