Atomic bonding and electrical potential at metal/oxide interfaces, a first principle study

TL;DR

This study uses first principle calculations to analyze how atomic bonding at metal/oxide interfaces influences electrical and mechanical properties, revealing the critical role of bonding configuration and oxygen atoms in device insulation.

Contribution

It provides new insights into the atomic-scale bonding effects at metal/oxide interfaces, emphasizing the impact on electrical potential and oxide thickness in miniaturized devices.

Findings

Interfacial bonding configuration critically affects properties.

Oxygen atoms better delimit oxide boundaries.

Cation-metal bonds enable potential leakage without diffusion.

Abstract

A number of electronic devices involve metal/oxide interfaces in their structure where the oxide layer plays the role of electrical insulator. As the downscaling of devices continues, the oxide thickness can spread over only a few atomic layers, making the role of interfaces prominent on its insulating properties. The prototypical Al/SiO2 metal/oxide interface is investigated using first principle calculations, and the effect of the interfacial atomic bonding is evidenced. It is shown that the interface bonding configuration critically dictates the mechanical and electronic properties of the interface. Oxygen atoms are found to better delimit the oxide boundaries than cations. Interfacial cation-metal bonds allow the metal potential to leak inside the oxide layer, without atomic diffusion, leading to a virtual oxide thinning.