Structural Properties and Thermodynamics of Hafnium sub-oxides in RRAM

TL;DR

This study uses ab initio simulations to analyze the structural, electronic, and thermodynamic properties of hafnium sub-oxides, providing insights relevant to the functioning of oxide-based RRAM devices.

Contribution

It offers a detailed computational analysis of hafnium sub-oxides' properties and their stability, advancing understanding of their role in RRAM technology.

Findings

Hafnium sub-oxides exhibit varying stability depending on oxygen content.

Progressive oxidation trends towards HfO2 are characterized.

Electronic properties suggest conductive regions within the oxide matrix.

Abstract

We study the structural and electronic properties of various hafnium sub-oxides HfzO from z = 9 to z = 0.5, by ab initio simulation using Density Functional Theory. The stability of these sub-oxides is studied against monoclinic HfO2. The progressive oxidation of a given HfzO is also envisaged toward stoichiometric HfO2. The analogy with a conductive region of electrons inside a HfO2 matrix is discussed within the context of Oxide-based Resistive Random Access Memories (OxRRAM) devices which employ hafnium dioxide as an insulator.