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US 6,803,615 B1Granted
Magnetic tunnel junction MRAM with improved stability
AssigneeWestern Digital (Fremont), LLC
InventorsKyusik Sin, Xizeng Shi, Hugh Craig Hiner
Life of this patent
Estimating the term…
Abstract
An MRAM cell includes a pinned layer, a free layer, and a bit line with a magnetic sheath. The magnetic sheath allows a magnetic field to circulate in a loop around the bit line. The looping magnetic field can couple with the magnetic field of the free layer for enhanced stability with respect to stray magnetic fields and elevated temperatures.
Claims47
An MRAM cell comprising:
- a magnetic tunneling junction including
- a free layer,
- a pinned layer, and
- a spacer layer disposed between the free layer and the pinned layer;
- a digit line including a digit line segment disposed proximate to the magnetic tunneling junction;
- a bit line including a bit line segment in electrical contact with the magnetic tunneling junction;
- and
- a magnetic liner layer disposed entirely around the bit line segment and contacting the free layer.
5 more elements
An MRAM cell comprising:
- a magnetic tunneling junction including
- a free layer having a magnetization orientation,
- a pinned layer, and
- an insulating spacer layer disposed between the free layer and the pinned layer;
- a digit line including a segment disposed proximate to the pinned layer;
- a bit line including a segment in electrical contact with the free layer;
- a magnetic liner layer disposed entirely around the bit line segment and contacting the free layer such that a magnetic field encircles the bit line segment.
4 more elements
An MRAM cell comprising:
- a magnetic tunneling junction including
- a free layer,
- a pinned layer, and
- an insulating spacer layer disposed between the free layer and the pinned layer;
- a digit line including a segment disposed proximate to the pinned layer, the digit line segment having a long axis defining a first direction;
- an electrically insulating spacer layer disposed between the digit line segment and the pinned layer;
- a bit line including a segment in electrical contact with the free layer, the bit line segment having a long axis defining a second direction substantially perpendicular to the first direction;
- a magnetic liner layer disposed entirely around the bit line segment and contacting the free layer.
5 more elements
An MRAM cell comprising:
- a magnetic tunneling junction including
- a free layer,
- a pinned layer, and
- an insulating spacer layer disposed between the free layer and the pinned layer;
- a digit line including a segment disposed proximate to the pinned layer, the digit line segment having a long axis defining a first direction;
- a bit line including a bit line segment in electrical contact with the free layer and having a long axis defining a second direction substantially perpendicular to the first direction;
- and
- a magnetic sheath disposed entirely around the bit line segment and magnetically coupled to the free layer.
5 more elements
Dependencies are inferred from the claim text.