IEEE Transactions on Magnetics · 2005 · 12 citations · 7 references
Natural SciencesMaterials EngineeringMaterials ScienceElectronic MaterialsMagnetic MaterialsThin FilmsFerromagnetic MaterialsFerromagnetismMagnetic AnisotropyMagnetic Recording MaterialsMagnetic Thin FilmsSpintronicsAnisotropy FieldIntrinsic AnisotropyMagnetic Materials CharacterizationMagnetic Tunneling JunctionsMagnetization CurvesMagnetization In Thin FilmsMagnetoresistive Random-access MemoryPinned Magnetic Layers
Toggle switching mode MRAM is tested and characterized with respect to the free- and pinned-layer material and thickness. With magnetization curves, we were able to find the optimum thickness combinations of free-layer and spacer materials. For CoFeB where the intrinsic anisotropy field ( Hi) is about 20-30 Oe, one needs to have a reasonably high exchange coupling field (Hex) to ensure large switching margin. In case of an NiFe/Ru/NiFe free-layer, Hi is usually much smaller than Hex, so that further decrease of Hex between two magnetic layers is needed. The pinned-layer roughness and thickness are other factors to be optimized to reduce the toggle switching field. High cell aspect ratio /spl ges/3.0 helps to minimize the switching distribution and enhance the switching stability.
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Antiferromagnetically coupled CoFeB∕Ru∕CoFeB trilayers
Applied Physics Letters · 2004 · 49 citations · Full text