Comparative Analysis of <i>n</i>- and <i>p</i>-Type Ferroelectric Tunnel Junctions Through Understanding of Non-FE Resistance Switching

Abstract

We re-evaluate the performance of the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${p}$ </tex-math></inline-formula> -type ferroelectric tunnel junction (FTJp) by introducing a perspective that includes non-ferroelectric (FE) resistive switching (RS). Contrary to the previous studies that FTJp exhibits significantly lower on-current density ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {on}}{)}$ </tex-math></inline-formula> compared to the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}$ </tex-math></inline-formula> -type FTJ (FTJ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\text {n}}{)}$ </tex-math></inline-formula> , our observations show that FTJp exhibits comparable <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {on}}$ </tex-math></inline-formula> to FTJn, thus achieving a higher tunneling electroresistance (TER) ratio. By analyzing low-frequency noise and temperature dependence of the fatigue rate, we demonstrate that the non-FE RS causes the increase in the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {on}}$ </tex-math></inline-formula> and TER ratio of FTJp. Furthermore, we discover a new advantage of FTJp: It exhibits lower read noise than FTJn in the operating region governed by the FE RS.