Dependence of Giant Tunnel Magnetoresistance of Sputtered CoFeB/MgO/CoFeB Magnetic Tunnel Junctions on MgO Barrier Thickness and Annealing Temperature

By J. Hayakawa, Shoji Ikeda, Fumihiro Matsukura, H. Takahashi, Hideo Ohno. 2005

232 citations recorded by the source corpus.

We investigated the dependence of giant tunnel magnetoresistance (TMR) on the thickness of an MgO barrier and on the annealing temperature of sputtered CoFeB/MgO/CoFeB magnetic tunnel junctions deposited on SiO2/Si wafers. The resistance-area product exponentially increases with MgO thickness, indicating that the quality of MgO barriers is high in the investigated thickness range of 1.15–2.4 nm. High-resolution transmission electron microscope images show that annealing at 375°C results in the formation of crystalline CoFeB/MgO/CoFeB structures, even though CoFeB electrodes are amorphous in the as-sputtered state. The TMR ratio increases with annealing temperature and is as high as 260% at room temperature and 403% at 5 K.

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

View Paper: https://www.semanticscholar.org/paper/a2764a696eac58c0d4d4d7994edaa40e7330e27d

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

1. Hideo Ohno
2. Fumihiro Matsukura
3. C. Marrows
4. Shoji Ikeda
5. T. Kawahara
6. R. Takemura
7. Kenchi Ito
8. T. Dietl

In Electronic, Optical and Magnetic Materials

1. Hideo Ohno
2. Fumihiro Matsukura
3. Shoji Ikeda
4. C. Marrows
5. T. Dietl

In Materials Chemistry

1. Hideo Ohno
2. Fumihiro Matsukura
3. C. Marrows
4. T. Dietl
5. T. Jungwirth
6. Daichi Chiba

Citations in the corpus

• Magnetic Tunnel Junctions for Spintronic Memories and Beyond (2007, background): “Employing a double-barrier structure has also been shown effective in increasing ∆V [76].”
• Spin-polarised currents and magnetic domain walls (2005, background): “The most recent developments at the time of writing are a 230% room temperature magnetoresistance in an ultrasmooth junction with a crystalline (001) MgO barrier but using amorphous CoFeB electrodes [43], rapidly followed by a 260% room temperature result in similar junction structure, but where the”
• Spin-transfer torque RAM technology: Review and prospect (2012, background): “Furthermore, Djavaprawira et al. demonstrated a TMR ratio of 230% at room temperature for sputtered Co60Fe20B20/MgO/Co60Fe20B20 IMTJs [19], and Hayakawa et al. demonstrated a TMR ratio of 260% for Co40Fe40B20/MgO/ Co40Fe40B20 IMTJs [20].”