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Effect of Tantalum Spacer Thickness and Deposition Conditions on the Properties of MgO/CoFeB/Ta/CoFeB/MgO Free Layers
- Source :
- IEEE Magnetics Letters, IEEE Magnetics Letters, IEEE, 2019, 10, pp.1-4. ⟨10.1109/LMAG.2019.2940572⟩
- Publication Year :
- 2019
- Publisher :
- Institute of Electrical and Electronics Engineers (IEEE), 2019.
-
Abstract
- To get stable perpendicularly magnetized tunnel junctions at small device dimensions, composite free layers that comprise two MgO/FeCoB interfaces as sources of interface anisotropy are generally used. Proper cristallisation and annealing robustness is typically ensured by the insertion of a spacer layer of the early transition metal series within the FeCoB layer. We study the influence of the spacer thickness and growth condition on the switching metrics of tunnel junctions thermally annealed at 400$^\circ$C for the case of 1-4 \r{A} Ta spacers. Thick Ta spacer results in a large anisotropies indicative of a better defined top FeCoB/MgO interface, but this is achieved at the systematic expense of a stronger damping. For the best anisotropy-damping compromise, junctions of diameter 22 nm can still be stable and spin-torque switched. Coercivity and inhomogeneous linewidth broadening, likely arising from roughness at the FeCoB/Ta interface, can be reduced if a sacrificial Mg layer is inserted before the Ta spacer deposition.<br />Comment: To appear in IEEE magnetics letters
- Subjects :
- Materials science
Annealing (metallurgy)
Tantalum
FOS: Physical sciences
chemistry.chemical_element
02 engineering and technology
Surface finish
01 natural sciences
law.invention
Condensed Matter::Materials Science
law
0103 physical sciences
[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]
Crystallization
Composite material
Anisotropy
Deposition (law)
010302 applied physics
Condensed Matter - Materials Science
Materials Science (cond-mat.mtrl-sci)
Coercivity
Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
021001 nanoscience & nanotechnology
Electronic, Optical and Magnetic Materials
chemistry
0210 nano-technology
Layer (electronics)
Subjects
Details
- ISSN :
- 19493088 and 1949307X
- Volume :
- 10
- Database :
- OpenAIRE
- Journal :
- IEEE Magnetics Letters
- Accession number :
- edsair.doi.dedup.....400c6f3b75f9ba046b5909b665595b13