Dynamic magnetic information storage or retrieval – Head – Hall effect
Patent
1996-11-27
1998-03-17
Heinz, A. J.
Dynamic magnetic information storage or retrieval
Head
Hall effect
257421, 365158, G11B 539, G11C 1100, H01L 4112
Patent
active
057294100
ABSTRACT:
A magnetic tunnel junction device for use as a magnetic memory cell or a magnetic field sensor has one fixed ferromagnetic layer and one sensing ferromagnetic layer formed on opposite sides of the insulating tunnel barrier layer, and a hard biasing ferromagnetic layer that is electrically insulated from but yet magnetostatically coupled with the sensing ferromagnetic layer. The magnetic tunnel junction in the device is formed on an electrical lead on a substrate and is made up of a stack of layers. The layers in the stack are an antiferromagnetic layer, a fixed ferromagnetic layer exchange biased with the antfferromagnetic layer so that its magnetic moment cannot rotate in the presence of an applied magnetic field, an insulating tunnel barrier layer in contact with the fixed ferromagnetic layer, and a sensing ferromagnetic layer in contact with the tunnel barrier layer and whose magnetic moment is free to rotate in the presence of an applied magnetic field. The stack is generally rectangularly shaped with parallel side edges. A layer of hard biasing ferromagnetic material is located near to but spaced from the side edges of the sensing ferromagnetic layer to longitudinally bias the magnetic moment of the sensing ferromagnetic layer in a preferred direction. A layer of electrically insulating material isolates the hard biasing material from the electrical lead and the sensing ferromagnetic layer so that sense current is not shunted to the hard biasing material but is allowed to flow perpendicularly through the layers in the stack.
REFERENCES:
patent: 3623038 (1971-11-01), Franklin et al.
patent: 5018037 (1991-05-01), Krounbi et al.
patent: 5390061 (1995-02-01), Nakatani et al.
patent: 5416353 (1995-05-01), Kamiguchi et al.
patent: 5432734 (1995-07-01), Kawano et al.
patent: 5465185 (1995-11-01), Heim et al.
patent: 5528440 (1996-06-01), Fontana et al.
patent: 5629922 (1997-05-01), Moordera
M. Julliere, "Tunneling Between Ferromagnetic Films", Physics Letters, vol. 54A, No. 3, Sep. 8, 1975, pp. 225-226.
K. Matsuyama et al., "Fabrication of Microstructured Magnetic Tunneling Valve Junction", IEEE Transactions on Magnetics, vol. 31, No. 6, Nov. 1995, pp. 3176-3178.
J.S. Moodera et al., "Ferromagnetic-insulator-ferromagnetic Tunneling: Spin-dependent Tunneling and Large Magnetoresistance in Trilayer Junctions", Symposium on Spin Tunneling and Injection Phenomena, Journal of Applied Physics, vol. 79, No. 8, Apr. 15, 1996, pp. 4724-4729.
Fontana, Jr. Robert Edward
Papworth Parkin Stuart Stephen
Berthold Thomas R.
Heinz A. J.
International Business Machines - Corporation
LandOfFree
Magnetic tunnel junction device with longitudinal biasing 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 tunnel junction device with longitudinal biasing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic tunnel junction device with longitudinal biasing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-963520