Multi-bit magnetic memory cells
OwnerJanice Nickel, Manoj Bhattacharyyainventors
Life of this patent
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Abstract
A magnetic memory cell includes first and second magneto-resistive devices connected in series. The first and second magneto-resistive devices have sense layers with different coercivities. Magnetic Random Access Memory (MRAM) devices may include arrays of these memory cells.
Claims25
A magnetic memory cell comprising first and second magneto-resistive devices connected in series, the first magneto-resistive device having a first sense layer, the second magneto-resistive device having a second sense layer, the first and second sense layers having different coercivities.
An information storage device comprising:
- an array of memory cells;
- and
- a plurality of first and second traces for the array, the first and second traces extending in different directions;
- each memory cell being at a cross point of a first trace and a second trace;
- at least some of the memory cells including series-connected first and second magnetic tunnel junctions, sense layers of the first and second junctions having different coercivities.
The information storage device of 13, wherein each first magnetic tunnel junction includes a first sense layer and a first pinned layer;
- and wherein each second magnetic tunnel junction includes a second sense layer and a second pinned layer.
A method of fabricating a magnetic memory device, the method comprising:
- forming a first stack of magnetic memory layers on a substrate, the first stack including a first sense layer;
- forming a second stack of magnetic memory layers on the first stack, the second stack including a second sense layer;
- the first and second sense layers being made to have different coercivities.
Dependencies are inferred from the claim text.