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Assessment of conduction mechanisms through MgO ultrathin barriers in CoFeB/MgO/CoFeB perpendicular magnetic tunnel junctions.
- Source :
-
Applied Physics Letters . 3/11/2019, Vol. 114 Issue 10, pN.PAG-N.PAG. 5p. 1 Chart, 5 Graphs. - Publication Year :
- 2019
-
Abstract
- Perpendicular magnetic tunnel junctions (p-MTJs) have been explored for spin transfer torque magnetic random access memory devices (STT-MRAMs). The current-induced switching (CIS) of the p-MTJs requires a relatively high current density (J); thereby, very thin insulating barriers are required, consequently increasing the risk of non-tunneling conduction mechanisms through the MgO film. In this work, we fabricated CoFeB/MgO/CoFeB p-MTJs and studied the CIS characteristics, with the obtained switching current densities of about 2 × 1010 A/m2. The filament conduction through the MgO film was induced by applying a high set current (Iset) until a significant decrease in the resistance (R) is observed. A decrease in R with increasing current (I) for parallel (P) and antiparallel (AP) states was observed. In contrast, an increase in R with the increasing I value was observed for filament p-MTJs. We used a two-channel model to extract the filament resistance (Rf) and filament current (If). The Rf dependence on the electrical power (Pf) was linearly fitted, and a heating coefficient β of about 6%/mW was obtained, which was much higher than 0.15%/mW obtained from the bulk metallic multilayers of the top electrode. The CIS for filament p-MTJs was modeled by considering the bias dependence of the tunneling and the thermal dependence of Rf, showing a significant change in the CIS curves and switching currents. Our study addresses the effect of filament conduction on the tunneling current of CoFeB/MgO/CoFeB p-MTJs, critical for the design and control of the p-MTJ based devices, such as STT-MRAMs. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00036951
- Volume :
- 114
- Issue :
- 10
- Database :
- Academic Search Index
- Journal :
- Applied Physics Letters
- Publication Type :
- Academic Journal
- Accession number :
- 135380548
- Full Text :
- https://doi.org/10.1063/1.5087952