Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30375
Study of Two Writing Schemes for a Magnetic Tunnel Junction Based On Spin Orbit Torque

Authors: K. Jabeur, L. D. Buda-Prejbeanu, G. Prenat, G. Di Pendina


MRAM technology provides a combination of fast access time, non-volatility, data retention and endurance. While a growing interest is given to two-terminal Magnetic Tunnel Junctions (MTJ) based on Spin-Transfer Torque (STT) switching as the potential candidate for a universal memory, its reliability is dramatically decreased because of the common writing/reading path. Three-terminal MTJ based on Spin-Orbit Torque (SOT) approach revitalizes the hope of an ideal MRAM. It can overcome the reliability barrier encountered in current two-terminal MTJs by separating the reading and the writing path. In this paper, we study two possible writing schemes for the SOT-MTJ device based on recently fabricated samples. While the first is based on precessional switching, the second requires the presence of permanent magnetic field. Based on an accurate Verilog-A model, we simulate the two writing techniques and we highlight advantages and drawbacks of each one. Using the second technique, pioneering logic circuits based on the three-terminal architecture of the SOT-MTJ described in this work are under development with preliminary attractive results.

Keywords: Circuit simulation, MRAM, Spintronic, Spin orbit Torque, Magnetic Tunnel Junction

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2842


[1] S. Wolf, D. Awschqlom, R. Buhrman, J. Daughton, S. Von Molnar, M. Roukes, A. Chtchelkanova, and M. Treger, Science 294, 1488 (2001).
[2] Freescale MRAM products update reports (2007)
[4] Everspin (2012).
[Online]. Available:
[5] B. N. Engel, J. Akerman, B. Butcher, R. W. Dave, M. DeHerrera, M. Durlam, G. Grynkewich, J. Janesky, S. V. Pietambaram, N. D. Rizzo, J. M. Slaughter, K. Smith, J. J. Sun, and S. Tehrani, “A 4-Mb toggle MRAM based on a novel bit and switching method,” IEEE Trans. Magn., vol. 41, no. 1, pp. 132–136, Jan. 2005
[6] L. Prejbeanu, M. Kerekes, R. C. Sousa, H. Sibuet, O. Redon, B. Dieny, and J. P. Nozieres, “Thermally assisted MRAM,” ` J. Phys, -Condens. Matter, p. 165218, 2007
[7] Erya Deng et al, “Low Power Magnetic Full-Adder based on Spin Transfer Torque MRAM”, IEEE Transactions on Magnetics, Vol PP, Issue 99, p. 1, Feb. 2013
[8] Hui Zhao et al, “A Scaling Roadmap and Performance Evaluation of In- Plane and Perpendicular MTJ Based STT-MRAMs for High-Density Cache Memory”, IEEE journal of Solid-State Circuits, Vol.48, No. 2, February 2013
[9] Patrick M. Braganca et al, “A Three-Terminal Approach to Developing Spin-Torque Written Magnetic Random Access Memory Cells”, IEEE transactions on nanotechnology, vol. 8, no. 2, march 2009
[10] Niladri Narayan Mojumder et al, “A Three-Terminal Dual-Pillar STTMRAM for High-Performance Robust Memory Applications”, IEEE transactions on electron devices, vol. 58, no. 5, may 2011
[11] Zhang Shuchao et al, “Simulation study of new 3-terminal devices for high speed STT-RAM”, Vol. 32, No. 7 Journal of Semiconductors July 2011
[12] Pietro Gambardella and Ioan Mihai Miron, “Current-induced spin−orbit torques”, doi: 10.1098/rsta.2010.0336, Phil. Trans. R. Soc. A 2011 369, 3175-3197
[13] Ioan mihai Miron et al, “Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection”, Nature 476, 189–193 doi: 10.1038/nature10309. 11, August 2011
[14] Luqiao Liu, “Magnetic switching by spin torque from the spin Hall effect”, Materials Science (cond-mat.mtrl-sci), arXiv:1110.6846, Nov 2011
[15] Luqiao Liu et al. “Spin-Torque Switching with the Giant Spin Hall Effect of Tantalum”, DOI: 10.1126/science.1218197 Science 336, 555 (2012)
[16] Sasikanth Manipatruni, Dmitri E. Nikonov, Ian A. Young, ”Voltage and Energy-Delay Performance of Giant Spin Hall Effect Switching for Magnetic Memory and Logic”, arXiv:1301.5374v1
[cond-mat.mes-hall]) (Submitted on 23 Jan 2013)
[17] Virgile Javerliac, “Développement d’un modèle compact de la jonction tunnel magnétique de première génération et son intégration dans la réalisation d’architectures logiques reprogrammables hybrides magnétique-CMOS », PhD, SPINTEC, INP, Nov 2006
[18] L. Landau and E. Lifshitz,”Theory of the dispertion of magnetic permeability in ferromagnetic bodies”. Phys. Z. Sowjetunion, 8:153– 169, 1935.
[19] M. Julliere, “Tunneling between ferromagnetic films”. Phys. Lett. A, 54:225–226, 1975.
[20] J. G Simmons. Generalized formula for the electric tunnel effect between similar electrodes separated by a thin insulating film. J. Appl. Phys., 34:1793–1803, June 1963.
[21] W. F. Brinkman, R. C. Dynes, and J. M. Rowell, “Tunneling conductance of asymmetrical barriers”. J. Appl. Phys., 41:1915–1921, April 1970.
[22] C. H. Back, R. Allenspash, W. Weber, S. S. P. Parkin, D. Weller, E. L. Garwin, and H. C. Siegmann, “Minimum field strength in precessional magnetization reversal”, Science, 285(5429) :864–867, August 1999.
[23] L. Q. Liu, T. Moriyama, D. C. Ralph, and R. A. Buhrman, “Reduction of the spin-torque critical current by partially canceling the free layer demagnetization field.” Appl. Phys. Lett. 94, 122508 (2009).
[24] T. Moriyama, T. J. Gudmundsen, P. Y. Huang, L. Q. Liu, D. A. Muller, D. C. Ralph, and R. A. Buhrman, “ Tunnel magneto resistance and spin torque switching in MgO-based magnetic tunnel junctions with a Co/Ni multilayer electrode”, Appl. Phys. Lett. 97, 072513 (2010)
[25] S. Ikeda, K. Miura, H. Yamamoto, K. Mizunuma, H. D. Gan, M. Endo, S. Kanai, J. Hayakawa, F. Matsukura & H. Ohno, “A perpendicular-anisotropy CoFeB–MgO magnetic tunnel junction”, Nature Materials 9, 721–724 (2010) doi:10.1038/nmat2804
[26] T. Kishi et al.,” Lower-current and fast switching of a perpendicular TMR for high speed and high density spin-transfer-torque MRAM”, in Proceedings of the IEEE International Electron Devices Meeting 2008, San Francisco, December 2008 (IEEE, New York, 2008); 10.1109/ IEDM.2008.4796680.