Static information storage and retrieval – Systems using particular element – Magnetoresistive
Reexamination Certificate
2006-11-30
2008-10-28
Elms, Richard T. (Department: 2824)
Static information storage and retrieval
Systems using particular element
Magnetoresistive
C365S189011
Reexamination Certificate
active
07443718
ABSTRACT:
A magnetic memory device comprises a magnetic tunnel junction (MTJ) having a ferromagnetic free layer, and exhibits a first, relatively high resistance state, and a second, relatively low resistance state. To write to the magnetic memory device a current IMTJis driven through the MTJ. For a first duration, the current is equal to a DC threshold current, being the DC current required to switch the multilayer structure between the first state and the second state. This induces a C-like domain structure in the free layer. For a second duration, the current IMTJis larger than the DC threshold current. This causes the MTJ to switch states. The current requited to cause switching is less than that required using a uniform current pulse.
REFERENCES:
patent: 6791873 (2004-09-01), Perner
patent: 6826086 (2004-11-01), Smith et al.
patent: 6956763 (2005-10-01), Akerman et al.
patent: 6980468 (2005-12-01), Ounadjela
patent: 6992910 (2006-01-01), Kochan et al.
patent: 2005/0047198 (2005-03-01), Engel et al.
Devolder, T. et al, “Precharging Stragegy to Accelerate Spin-Transfer Switching Below the nanosecond,” Applied Physics Letters 86, 2005 American Institute of Physics, pp. 062505-1-062505-3 (3 pages).
Recent Developments in Magnetic Tunnel Junction MRAM, Tehrani et al., IEEE Transactions on Magnetics, vol. 36, p. 2752 (2000).
Emission of Spin Waves by a Magnetic Multilayer Traversed by a Current, Berger, Physical Review, vol. 54 p. 9353 (1996).
Highly Scalable MRAM using Field Assisted current Induced Switching, Jeong et al. 2005 Symposium on VLSI technology Digest of Technical Papers, p. 184.
Ito Kenchi
Kawahara Takayuki
Takahashi Hiromasa
Takemura Riichiro
Antonelli, Terry Stout & Kraus, LLP.
Elms Richard T.
Hitachi , Ltd.
Le Toan
LandOfFree
Magnetic memory device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetic memory device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic memory device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4000603