MRAM Fundamentals and Devices

  • Hiroaki YodaEmail author
Reference work entry


This chapter covers the entire gamut of MRAM, from the fundamental physics of magnetism, magnetic materials used in MTJ elements, history of MRAM developments, and innovations which were keys to MRAM, to important designing points, MRAM scalability, and expected future evolutions of MRAM.

The chapter is expected to help engineers who are not familiar with MRAM to learn MRAM and develop a deeper understanding of its concepts, so that they can be more creative in their work. The chapter will also help researchers to make innovations for scalability and for memory hierarchy evolution with MRAM.


Magnetic Layer Memory Hierarchy Threshold Curve Phase Change Memory Design Node 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

List of Abbreviations


Anisotropic Magneto Resistance


Current Induced Magnetization Reversal


Error Correction Code


Ferroelectric RAM


Giant MagnetoResistance


Magnetoresistive Random Access Memory


Magnetic Tunnel Junction


Normally-Off Computing


Phase change RAM, also called PCRAM, PCM, or Ovonic Memory


Resistive RAM


Alternative term for STT-writing MRAM


Tunnel MagnetoResistance



I would like to thank all members of the Spin-RAM working group of the NEDO Spintronics Nonvolatile Devices project (2006–2010), which was organized by the collaboration of AIST, Toshiba, Tohoku University, Osaka University, and University of Electro-Communications, for their contributions to the development of Spin-RAM.


  1. 1.
    Durlam M, Addie D, Akerman J, Butcher B, Brown P, Chan J, DeHerrera M, Engel BN, Feil B, Grynkewich G, Janesky J, Johnson M, Kyler K, Molla J, Martin J, Nagel K, Ren J, Rizzo ND, Rodriguez T, Savtchenko L, Salter J, Slaughter JM, Smith K, Sun JJ, Lien M, Papworth K, Shah P, Qin W, Williams R, Wise L, Tehrani S (2003) A 0.18 μm 4 Mb toggling MRAM. In: 2003 I.E. international electron devices meeting (IEDM) technical digest, Washington, DC, pp 995–997Google Scholar
  2. 2.
    Yoda H et al (2007) Presented at 7th international workshop on future information processing technologies, session III, Dresden GermanyGoogle Scholar
  3. 3.
    Nakayama M, Kai T, Shimomura N, Amano M, Kitagawa E, Nagase T, Yoshikawa M, Kishi T, Ikegawa S, Yoda H (2008) Spin transfer switching in TbCoFe/CoFeB/MgO/CoFeB/TbCoFe magnetic tunnel junctions with perpendicular magnetic anisotropy. J Appl Phys 103:07A710-1-3Google Scholar
  4. 4.
    Nagase T, Nishiyama K, Nakayama M, Shimomura N, Amano M, Kishi T, Yoda H (2008) Spin transfer torque switching in perpendicular magnetic tunnel junction with Co based multilaper. In: Presented at American Physical Society March meeting, New OrleansGoogle Scholar
  5. 5.
    Kishi T, Yoda H, Kai T, Nagase T, Kitagawa E, Yoshikawa M, Nishiyama K, Daibou T, Nagamine M, Amano M, Takahashi S, Nakayama M, Shimomura N, Aikawa H, Ikegawa S, Yuasa S, Yakushiji K, Kubota H, Fukushima A, Oogane M, Miyazaki T, Ando K (2008) Lower-current and fast switching of a perpendicular TMR for high speed and high density spin-transfer-torque MRAM. In: 2008 I.E. international electron devices meeting (IEDM) technical digest, San Francisco, pp 309–312Google Scholar
  6. 6.
    Daibou T, Yoshikawa M, Kitagawa E, Nagase T, Nishiyama K, Nagamine M, Amano M, Nakayama M, Kai T, Kishi T, Yoda H (2010) Spin transfer torque switching in perpendicular magnetic tunnel junctions using L10-ordered FePd electrodes. In: Presented at the 11th joint MMM/Intermag conference, Washington, DCGoogle Scholar
  7. 7.
    Yoda H, Kishi T, Nagase T, Yoshikawa M, Nishiyama K, Kitagawa E, Daibou T, Amano M, Shimomura N, Takahashi S, Kai T, Nakayama M, Aikawa H, Ikegawa S, Nagamine M, Ozeki J, Mizukami S, Oogane M, Ando Y, Yuasa S, Yakushiji K, Kubota H, Suzuki Y, Nakatani Y, Miyazaki T, Koji A (2010) High efficient spin transfer torque writing on perpendicular magnetic tunnel junctions for high density MRAMs. Curr Appl Phys 10:e87–e89CrossRefADSGoogle Scholar
  8. 8.
    Yoda H, Fujita S, Shimomura N, Kitagawa E, Abe K, Nomura K, Noguchi H, Ito J (2012) Progress of STT-MRAM technology and the effect on normally-off computing systems. In: Proceedings of IEDM technical digest, San Francisco, p 259Google Scholar
  9. 9.
    Kitagawa E, Fujita S, Nomura K, Noguchi H, Abe K, Ikegami K, Daibou T, Kato Y, Kamata C, Kashiwada S, Shimomura N, Ito J, Yoda H (2012) Impact of ultra low power and fast write operation of advanced perpendicular MTJ on power reduction in for high performance mobile CPU. In: Proceedings of IEDM technical digest, San Francisco, p 677Google Scholar
  10. 10.
    Tomita H, Nozaki T, Seki T, Nagase T, Nishiyama K, Kitagawa E, Yoshikawa M, Daibou T, Nagamine M, Kishi T, Ikegawa S, Shimomura N, Yoda H, Suzuki Y (2011) High-speed spin-transfer switching in GMR nano-pillars with perpendicular anisotropy. IEEE Trans Magn 47:1599–1602; Tomita H et al (2011) IEEE Magnetics Letter (in press)Google Scholar
  11. 11.
    Slonczewski JC (1996) Current-driven excitation of magnetic multilayers. J Magn Magn Mater 159:L1–L7CrossRefADSGoogle Scholar
  12. 12.
    Berger L (1996) Emission of spin waves by a magnetic multilayer traversed by a current. Phys Rev B 54:9353–9358CrossRefADSGoogle Scholar
  13. 13.
    Baibich MN, Broto JM, Fert A, Nguyen Van Dau F, Petroff F, Etienne P, Creuzet G, Friederich A, Chazelas J (1988) Giant magnetoresistance of (001)Fe/(001)Cr magnetic superlattices. Phys Rev Lett 61:2472–2475CrossRefADSGoogle Scholar
  14. 14.
    Binasch G, Grunberg P, Saurenbach F, Zinn W (1989) Enhanced magnetoresistance in layered magnetic structures with antiferromagnetic interlayer exchange. Phys Rev B39:4282Google Scholar
  15. 15.
    Miyazaki T, Tezuka N (1995) Giant magnetic tunneling effect in Fe/Al2O3/Fe junction. J Magn Magn Mater 139:L231–L234CrossRefADSGoogle Scholar
  16. 16.
    Moodera JS, Kinder LR, Wong TM, Meservey R (1995) Large magnetoresistance at room temperature in ferromagnetic thin film tunnel junctions. Phys Rev Lett 74:3273–3276CrossRefADSGoogle Scholar
  17. 17.
    Myers EB, Ralph DC, Katine JA, Louie RN, Buhrman RA (1999) Current-induced switching of domains in magnetic multilayer devices. Science 285:867–870CrossRefGoogle Scholar
  18. 18.
    Huai Y, Albert F, Nguyen P, Pakala M, Valet T (2004) Observation of spin-transfer switching in deep submicron-sized and low-resistance magnetic tunnel junctions. Appl Phys Lett 84:3118–3120CrossRefADSGoogle Scholar
  19. 19.
    Kubota H, Fukushima A, Ootani Y, Yuasa S, Ando K, Maehara H, Tsunekawa K, Djayaprawira DD, Watanabe N, Suzuki Y (2005) Evaluation of spin-transfer switching in CoFeB/MgO/CoFeB magnetic tunnel junctions. Jpn J Appl Phys 44:L1237–L1240CrossRefADSGoogle Scholar
  20. 20.
    Butler WH, Zhang X-G, Schulthess TC, Maclare JM (2001) Spin-dependent tunneling conductance of Fe|MgO|Fe sandwiches. Phys Rev B 63:054416CrossRefADSGoogle Scholar
  21. 21.
    Mathon J, Umerski A (2001) Theory of tunneling magnetoresistance of an epitaxial Fe/MgO/Fe(001) junction. Phys Rev B 63:220403RCrossRefADSGoogle Scholar
  22. 22.
    Yuasa S, Fukushima A, Nagahara T, Ando K, Suzuki Y (2004) High tunnel magnetoresistance at room temperature in fully epitaxial Fe/MgO/Fe tunnel junctions due to coherent spin-polarized tunneling. Jpn J Appl Phys 43:L588–L590CrossRefADSGoogle Scholar
  23. 23.
    Parkin SSP, Kaiser C, Panchula A, Rice PM, Hughes B, Samant M, Yang SH (2004) Giant tunnelling magnetoresistance at room temperature with MgO (100) tunnel barriers. Nat Mater 3:862–867CrossRefADSGoogle Scholar
  24. 24.
    Meng H, Wanga J-P (2006) Spin transfer in nanomagnetic devices with perpendicular anisotropy. Appl Phys Lett 88:172506CrossRefADSGoogle Scholar
  25. 25.
    Mangin S, Ravelosona D, Katine JA, Carey MJ, Terris BD, Fullerton EE (2006) Current-inducedmagnetization reversal in nanopillars with perpendicular anisotropy. Nat Mater 5:210–215CrossRefADSGoogle Scholar
  26. 26.
    Seki T, Mitani S, Yakushiji K, Takanashi K (2006) Magnetization reversal by spin-transfer torque in 90° configuration with a perpendicular spin polarizer. Appl Phys Lett 89:172504CrossRefADSGoogle Scholar
  27. 27.
    Tsuchida K, Inaba T, Fujita K, Ueda Y, Shimizu T, Asao Y, Kajiyama T, Iwayama M, Sugiura K, Ikegawa S, Kishi T, Kai T, Amano M, Shimomura N, Yoda H, Watanabe Y (2010) A 64 Mb MRAM with clamped-reference and adequate-reference schemes. In: 2010 I.E. international solid-state circuits conference (ISSCC) technical digest, San Francisco, pp 258–260Google Scholar
  28. 28.
    Yoda H, Kai T, Inaba T, Iwata Y, Shimomura N, Ikegawa S, Tsuchida K, Asao Y, Kishi T, Ueda T, Takahashi S, Nagamine M, Kajiyama T, Yoshikawa M, Amano M, Nagase T, Hosotani K, Nakayama M, Shimizu Y, Aikawa H, Nishiyama K, Kitagawa E, Akizawa RT, Ueda Y, Iwayama M, Itagaki K (2006) 1.8 V power supply 16 Mb-MRAM with 42.3% array efficiency. IEEE Trans Magn 42(10):2724–2726CrossRefADSGoogle Scholar
  29. 29.
    Savchenko L, Engel BN, Rizzo ND, Deherrera MF, Janesky JA (2003) US Patent 6545906b1Google Scholar
  30. 30.
    Kai T, Ozeki J, Nakayama M, Aikawa H, Ikegawa S, Yoda H (2008) Scalability of perpendicular MRAM using spin transfer torque switching. In: Presented at the 32th annual conference on magnetics in Japan, 15pB 9, TagajoGoogle Scholar
  31. 31.
    Ando K (2001) Nonvolatile magnetic memory. J FED 12(4):89–95Google Scholar
  32. 32.
    Abe K, Shinobu F, Lee TH (2005) Novel nonvolatile logic circuits with three-dimensionally stacked nanoscale memory device. NSTI Nanotech 3:203–206Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  1. 1.Toshiba Electronics Korea CorporationSeoulRepublic of Korea

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