Abstract: A magnetic tunnel junction cell having a free layer, a ferromagnetic pinned layer, and a barrier layer therebetween. The free layer has a central ferromagnetic portion and a stabilizing portion radially proximate the central ferromagnetic portion. The construction can be used for both in-plane magnetic memory cells where the magnetization orientation of the magnetic layer is in the stack film plane and out-of-plane magnetic memory cells where the magnetization orientation of the magnetic layer is out of the stack film plane, e.g., perpendicular to the stack plane.
Abstract: Non-volatile static random access memory (nvSRAM) that has a six transistor static random access memory (6T SRAM) cell electrically connected to a non-volatile random access memory (nvRAM) cell. The nvRAM cell has first and second variable magnetic resistors and first, second and third transistors.
Type:
Grant
Filed:
February 12, 2009
Date of Patent:
June 5, 2012
Assignee:
Seagate Technology LLC
Inventors:
Yongchul Ahn, Antoine Khoueir, Yong Lu, Hongyue Liu
Abstract: A spin-transfer torque memory apparatus and non-destructive self-reference read schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage and storing the first bit line read voltage in a first voltage storage device. The magnetic tunnel junction data cell has a first resistance state. Then the method includes applying a second read current thorough the magnetic tunnel junction data cell having the first resistance state and forming a second bit line read voltage and storing the second bit line read voltage in a second voltage storage device. The first read current is less than the second read current. Then the stored first bit line read voltage is compared with the stored second bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state.
Type:
Grant
Filed:
June 27, 2008
Date of Patent:
February 14, 2012
Assignee:
Seagate Technology LLC
Inventors:
Yiran Chen, Hai Li, Hongyue Liu, Ran Wang, Dimitar V. Dimitrov