Flicker Noise Behavior in Resistive Memory Devices With Double-Layered Transition Metal Oxide

Abstract

Characteristics of flicker (or <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{1}/f$</tex></formula> ) noise have been investigated in resistive-switching random access memory (RRAM) devices with <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX"> $\hbox{TiN/Ti/TiO}_{x}/\hbox{HfO}_{x}/\hbox{TiN}$</tex></formula> double-layered (DL) metal oxide structure. In DL-RRAMs, no significant difference is found in the normalized current noise power spectral densities of the high- and low-resistance states, unlike RRAMs with the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{TiN/Ti/TiO}_{x}/ \hbox{TiN}$</tex></formula> SL structure. Based on comparative analysis, we demonstrate that the dominant <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{1}/f$</tex></formula> noise source of DL-RRAM is located near the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{TiO}_{x}/\hbox{HfO}_{x}$</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">$\hbox{HfO}_{x}/\hbox{TiN}$</tex></formula> interfaces, and the origin of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$ \hbox{1}/f$</tex></formula> noise is modeled to be the mobility fluctuation. A unique measurement method, which completely breaks down the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{HfO}_{x}$</tex></formula> layer only, was employed for a systematic analysis of RRAMs with three different structures.