Abstract:
A method and system for providing a magnetic memory is described. The method and system include providing a plurality of magnetic storage cells, a plurality of word lines, and a plurality of bit lines. Each of the plurality of magnetic storage cells includes a plurality of magnetic elements and at least one selection transistor. Each of the plurality of magnetic elements is capable of being programmed using spin transfer induced switching by a write current driven through the magnetic element. Each of the plurality of magnetic elements has a first end and a second end. The at least one selection transistor is coupled to the first end of each of the plurality of magnetic elements. The plurality of word lines is coupled with the plurality of selection transistors and selectively enables a portion of the plurality of selection transistors.
Abstract:
A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, nonmagnetic spacer, free, and heat assisted switching layers. The spacer layer resides between the pinned and free layers. The free layer resides between the spacer and heat assisted switching layers. The heat assisted switching layer improves thermal stability of the free layer when the free layer is not being switched, preferably by exchange coupling with the free layer. The free layer is switched using spin transfer when a write current is passed through the magnet element. The write current preferably also heats the magnetic element to reduce the stabilization of the free layer provided by the heat assisted switching layer. In another aspect, the magnetic element also includes a second free layer, a second, nonmagnetic spacer layer, and a second pinned layer. The heat assisted switching layer resides between the two free layers, which are magnetostatically coupled. The second spacer layer resides between the second free and second pinned layers.
Abstract:
A method and system for providing a magnetic element are disclosed. The method and system include providing first (102) and second (120) pinned layers, a free layer (114), and first (112) and second (116) barrier layers between the first and second pinned layers, respectively, and the free layer. The first barrier layer is oreferably crystalline MgO, which is insulating, and configured to allow tunneling through the first barrier layer. Furthermore, the first barrier layer has an interface with another layer, such as the free layer or the first pinned layer. The interface has a structure that provides a high spin polarization of at least fifty percent and preferably over eighty percent. The second barrier layer is insulating and configured to allow tunneling through the second barrier layer. The magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element.
Abstract:
A method and system for providing a magnetic element are disclosed. The method and system include providing a pinned layer, providing a spacer layer, and providing a free layer. The free layer is ferrimagnetic and includes at least one of a conductive ferrite, a garnet, a ferrimagnetic alloy excluding a rare earth, a heavy rare- earth-transition metal alloy, a half-metallic ferrimagnetic, and a bilayer. The bilayer includes a rare earth-transition metal alloy layer and a spin current enhancement layer. The magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element.
Abstract:
A method and system for providing a magnetic element are disclosed. The method and system include providing a pinned layer, a free layer, and a spacer layer between the pinned layer and the free layer. The spacer layer is insulating and has an ordered crystal structure. The spacer layer is also configured to allow tunneling through the spacer layer. In one aspect, the free layer is comprised of a single magnetic layer having a particular crystal structure and texture with respect to the spacer layer. In another aspect, the free layer is comprised of two sublayers, the first sublayer having a particular crystal structure and texture with respect to the spacer layer and the second sublayer having a lower moment. In still another aspect, the method and system also include providing a second pinned layer and a second spacer layer that is nonmagnetic and resides between the free layer and the second pinned layer. The magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element.
Abstract:
A method and system for providing a magnetic memory is disclosed. The method and system include providing a plurality of magnetic elements and providing at least one stress-assist layer. Each of the plurality of magnetic elements is configured to be written using spin transfer. The at least one stress-assist layer is configured to exert at least one stress on at least one magnetic element of the plurality of magnetic elements during writing. The reduction of spin-transfer switching current is due to stress exerted by the stress-assist layer on the magnetic elements during writing. Stability of the magnetic memory with respect to thermal fluctuations is not compromised because the energy barrier between the two magnetization states is unchanged once the switching current is turned off.