Nanoscale Transformations in Metastable, Amorphous, Silicon‐Rich Silica

Adnan Mehonic,Alexander L Shluger,Richard J Chater,Sarah Fearn,Stephen Hudziak,Mark Buckwell,Luca Montesi,Manveer Singh Munde,David Mcphail,Michel Bosman,Anthony J Kenyon,David Gao

doi:10.1002/adma.201601208

Abstract

Electrically biasing thin films of amorphous, substoichiometric silicon oxide drives surprisingly large structural changes, apparent as density variations, oxygen movement, and ultimately, emission of superoxide ions. Results from this fundamental study are directly relevant to materials that are increasingly used in a range of technologies, and demonstrate a surprising level of field-driven local reordering of a random oxide network.

Highlights

Functional oxides are fundamental to modern microelectronics as high quality insulators, transparent conductors, electroluminescent and electrochromic materials, amongst other applications
The dynamic response of amorphous substoichiometric oxides to electrical stresses encountered in applications including resistance switching,[1]
There have been reports of intrinsic reversible breakdown of silicon oxide,[9,10,11] usually ascribed to the formation of chains of oxygen vacancies[12] produced by fielddriven movement of oxygen ions. The reversibility of these changes is of the greatest interest, as it probes the dynamics of oxides under controlled stress and provides a model for the initial stages of irreversible dielectric breakdown

Summary

Introduction

Functional oxides are fundamental to modern microelectronics as high quality insulators, transparent conductors, electroluminescent and electrochromic materials, amongst other applications. Abrupt changes of resistance in response to electrical stress are hallmarks of correlated electron and ion dynamics and an obvious manifestation of structural dynamics; such phenomena have been reported in a variety of oxides with a range of stoichiometries in different applications.

Results

Conclusion