Hydrogen-Induced Oxygen Vacancy Bistability and Its Impact on RRAM Device Operation

Abstract

Hydrogen-induced bistability of an oxygen vacancy defect was investigated in hafnium oxide using density functional theory calculations. With the injection of an excess electron, a bistability is induced by hydrogen site preference change due to excess electron charge redistribution near the hydrogen and oxygen vacancy. The spatial charge delocalization of electrons is altered in this transition, and this process can have a strong effect on the charge transport probability near conductive filaments of resistive random access memories. If the thickness of HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> scales down below 1 nm, the bistability can also be used to realize an atomic resistive switch controlled by a single hydrogen atom.