TY - JOUR

T1 - Ab initio study of oxygen vacancy filament formation at Ta/HfO2 interface

AU - Zhang, Donglan

AU - Wang, Jiong

AU - Wu, Qing

AU - Du, Yong

AU - Holec, David

N1 - Publisher Copyright: © 2024

PY - 2024/6

Y1 - 2024/6

N2 - The resistive switching (RS) behavior of resistive random access memory (RRAM) based on oxygen vacancy (V O) conduction is significantly affected by the interface properties between metal electrode and oxide layer, yet the modulation between the RS behavior and the physico-chemical properties of the interface is still not very clear. In this study, the correlative role of Ta/HfO 2 interface with the RS behavior in HfO 2-based RRAM is explored at atomic level. First-principles thermodynamic calculations show that the strong interaction between three-fold oxygen vacancies (V O3) leads to a formation of V O3-based conductive filament (CF) along direction perpendicular to the interface. Four-fold oxygen vacancies (V O4) make a major contribution to the re-formation and growth of CFs during the set process by diffusing into the residual filaments. The results of electronic properties further indicate that as the number of V Os perpendicular to the interface increases, the charge redistribution between O and Ta atoms at the interface is significantly increased, and more electron clouds are gathered around V Os. This is the underlying mechanism of forming a conductive channel. This study reveals the important regulation mechanism of the interface characteristics between metal electrode and oxide layer in RRAM on the formation and growth of V O-based CFs.

AB - The resistive switching (RS) behavior of resistive random access memory (RRAM) based on oxygen vacancy (V O) conduction is significantly affected by the interface properties between metal electrode and oxide layer, yet the modulation between the RS behavior and the physico-chemical properties of the interface is still not very clear. In this study, the correlative role of Ta/HfO 2 interface with the RS behavior in HfO 2-based RRAM is explored at atomic level. First-principles thermodynamic calculations show that the strong interaction between three-fold oxygen vacancies (V O3) leads to a formation of V O3-based conductive filament (CF) along direction perpendicular to the interface. Four-fold oxygen vacancies (V O4) make a major contribution to the re-formation and growth of CFs during the set process by diffusing into the residual filaments. The results of electronic properties further indicate that as the number of V Os perpendicular to the interface increases, the charge redistribution between O and Ta atoms at the interface is significantly increased, and more electron clouds are gathered around V Os. This is the underlying mechanism of forming a conductive channel. This study reveals the important regulation mechanism of the interface characteristics between metal electrode and oxide layer in RRAM on the formation and growth of V O-based CFs.

KW - Conductive filaments

KW - Interface

KW - Oxygen vacancy

KW - Resistive switching

KW - RRAM

UR - http://www.scopus.com/inward/record.url?scp=85191762298&partnerID=8YFLogxK

U2 - 10.1016/j.surfin.2024.104418

DO - 10.1016/j.surfin.2024.104418

M3 - Article

VL - 49.2024

JO - Surfaces and Interfaces

JF - Surfaces and Interfaces

SN - 2468-0230

IS - June

M1 - 104418

ER -