Large enhanced perpendicular magnetic anisotropy in CoFeB/MgO system with the typical Ta buffer replaced by an Hf layer

By T. Liu, J. W. Cai, Li Sun. 2012

162 citations recorded by the source corpus.

By systematically comparing the magnetic properties of the Ta/CoFeB/Ta and MgO/CoFeB/MgO structures with and without a submonolayer of MgO, Ta, V, Nb, Hf and W inserted in the middle of the CoFeB layer, we have proved that the observed perpendicular magnetic anisotropy (PMA) in Ta/CoFeB/MgO sandwiches is solely originated from the CoFeB/MgO interface with the Ta buffer acting to enhance the CoFeB/MgO interface anisotropy significantly. Moreover, replacing Ta with Hf causes the CoFeB/MgO interfacial PMA further enhanced by 35%, and the CoFeB layer with perpendicular magnetization has a much larger critical thickness accordingly, leaving a wider thickness margin for the CoFeB/MgO-based perpendicular magnetic tunnel junction optimization. Also the sputter deposited thin Hf films are amorphous with low surface roughness. These results will ensure the Hf/CoFeB/MgO more promising material system for PMA device development. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4748337]

Subfields: Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/318b2d747aa528b6f75a67b813a4b42396baf233

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In Atomic and Molecular Physics, and Optics

1. Juan G. Alzate
2. M. Chshiev
3. Kang L. Wang
4. Bernard Dieny
5. Jordan A. Katine

In Electronic, Optical and Magnetic Materials

1. Juan G. Alzate
2. M. Chshiev
3. Bernard Dieny
4. Kang L. Wang

In Materials Chemistry

1. M. Chshiev
2. Bernard Dieny
3. Kang L. Wang

Citations in the corpus

• Perpendicular magnetic anisotropy at transition metal/oxide interfaces and applications (2017, background): “Liu, Cai, and Sun (2012) substituted a Hf buffer for the Ta buffer and observed a 35% increase in PMA at the CoFeB=MgO interface.”
• Electric-Field-Controlled Magnetoelectric RAM: Progress, Challenges, and Scaling (2015, result): “As an example, the use of Hf and Mo seed layers has resulted in a larger Ki compared with that of the Ta layer, which is an important requirement for scaling of MeRAM [39], [40] (see Section III-E), while very large VCMA values have been observed in V|Fe-based films [41].”