MRS Proceedings

Articles

First-principles investigation of the conductive filament configuration in rutile TiO2-x ReRAM

2012 MRS Spring Meeting.

Liang Zhaoa1, Seong-Geon Parka2, Blanka Magyari-Köpea1 and Yoshio Nishia1

a1 Department of Electrical Engineering, Stanford University, 420 Via Palou Mall, Stanford, CA 94305, U.S.A.

a2 Department of Material Science and Engineering, Stanford University, 420 Via Palou Mall, Stanford, CA 94305, U.S.A.

ABSTRACT

The interactions and ordering of oxygen vacancies in rutile TiO2 were thoroughly investigated by density functional calculations to search for atomic configurations of the conductive filament. As random isolated vacancies could not support the low-resistance state conduction in TiO2 ReRAM, vacancy ordering was introduced in [110] and [001] directions of the lattice to study the electronic structures. The calculation results revealed that a di-vacancy chain in [001] direction makes the electrons delocalized in that direction, which is identified as a possible configuration of the conductive filament. This low-resistance state can be effectively disrupted by moving oxygen vacancies out of the filament to reach high-resistance states.

Key Words:

  • memory;
  • simulation;
  • defects
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