Static information storage and retrieval – Systems using particular element – Magnetic thin film
Patent
1997-07-16
1998-11-24
Nelms, David C.
Static information storage and retrieval
Systems using particular element
Magnetic thin film
365158, G11C 1115
Patent
active
058416927
ABSTRACT:
A magnetic tunnel junction (MTJ) device is usable as a magnetic field sensor or as a memory cell in a magnetic random access (MRAM) array. The MTJ device has a "pinned" ferromagnetic layer whose magnetization is oriented in the plane of the layer but is fixed so as to not be able to rotate in the presence of an applied magnetic field in the range of interest, a "free" ferromagnetic layer whose magnetization is able to be rotated in the plane of the layer relative to the fixed magnetization of the pinned ferromagnetic layer, and an insulating tunnel barrier layer located between and in contact with both ferromagnetic layers. The pinned ferromagnetic layer is formed as a sandwich of two antiferromagnetically coupled ferromagnetic layers separated by a metallic layer. The free and pinned ferromagnetic layers are located in separate spaced-apart planes so as to not overlap the tunnel barrier layer. An insulating layer surrounds the lateral perimeter of at least the free ferromagnetic layer and supports an electrical lead that makes contact with the free ferromagnetic layer.
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Gallagher William Joseph
Papworth Parkin Stuart Stephen
Slonczewski John Casimir
Sun Jonathan Zanhong
Berthold Thomas R.
International Business Machines - Corporation
Nelms David C.
Tran Michael T.
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