A Comparison of the Radiation Response of ${\rm TaO}_{\rm x}$ and ${\rm TiO}_2$ Memristors

Abstract

The effects of radiation on memristors created using tantalum oxide and titanium oxide are compared. Both technologies show changes in resistance when exposed to 800 keV Ta ion irradiation at fluences above <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$10^{10}~\hbox{cm}^{\hbox{-}2}$</tex> </formula> . <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm TaO}_{\rm x}$</tex></formula> memristors show a gradual reduction in resistance at high fluences whereas <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm TiO}_2$</tex> </formula> memristors show gradual increases in resistance with inconsistent decreases. After irradiation <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm TaO}_{\rm x}$</tex></formula> devices remain fully functional and can even recover resistance with repeated switching. <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\rm TiO}_2$</tex></formula> devices are more variable and exhibit significant increases and decreases in resistance when switching after irradiation. Irradiation with 28 MeV Si ions causes both technologies to switch from the off-state to the on-state when ionizing doses on the order of 60 Mrad(Si) or greater (as calculated by SRIM) are reached without applying current or voltage to the part. Irradiation with 10 keV X-rays up to doses of 18 Mrad(Si) in a single step show little effect on either technology. <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm TaO}_{\rm x}$</tex></formula> and <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm TiO}_2$</tex></formula> memristors both show high tolerance for displacement damage and ionization damage and are promising candidates for future radiation-hardened non-volatile memory applications.