公开(公告)号：US20070109839A1

公开(公告)日：2007-05-17

申请号：US11273214

申请日：2005-11-14

申请人： Romney Katti ,  Owen Hynes ,  Daniel Reed ,  Hassan Kaakani

发明人： Romney Katti ,  Owen Hynes ,  Daniel Reed ,  Hassan Kaakani

IPC分类号： G11C11/00

CPC分类号： G11C11/16

摘要： A new read scheme is provided for an MRAM bit having a pinned layer (fixed) and a storage layer (free) sandwiching a nonmagnetic spacer layer. By applying a magnetic field to the bit at least partially orthogonal to the easy axis of the bit, the magnetization direction of the storage layer can be partially rotated or canted without switching the logical state of the MRAM bit. The resistivity of the bit is measured (calculated based on a voltage/current relationship) in two ways: (i) with the magnetization direction of the storage layer partially rotated in a first direction and (ii) with the magnetization direction of the storage layer in its bi-stable orientation parallel to the easy axis. Those measures can then be used to compare and determine the logical state of the storage layer. For instance, if the canted resistivity is greater than the uncanted resistivity then the magnetization directions of the pinned and storage layer are parallel, and if the canted resistivity is less than the uncanted resistivity then the magnetization directions of the pinned and storage layer are opposite.

摘要翻译： 为具有钉扎层（固定）和夹持非磁性间隔层的存储层（自由）的MRAM位提供了新的读取方案。 通过将至少部分地正交于该位的容易轴的位施加磁场，可以在不切换MRAM位的逻辑状态的情况下部分地旋转或倾斜存储层的磁化方向。 以两种方式测量位的电阻率（基于电压/电流关系计算）：（i）存储层的磁化方向在第一方向上部分旋转，并且（ii）与存储层的磁化方向 其平行于易轴的双稳态取向。 然后可以使用这些措施来比较和确定存储层的逻辑状态。 例如，如果倾斜电阻率大于无电阻率，那么被钉扎层和存储层的磁化方向是平行的，并且如果斜面电阻率小于未被覆盖的电阻率，那么被钉扎和存储层的磁化方向相反。

公开(公告)号：US07248496B2

公开(公告)日：2007-07-24

申请号：US11273214

申请日：2005-11-14

申请人： Romney R. Katti ,  Owen J. Hynes ,  Daniel S. Reed ,  Hassan Kaakani

发明人： Romney R. Katti ,  Owen J. Hynes ,  Daniel S. Reed ,  Hassan Kaakani

IPC分类号： G11C7/00

CPC分类号： G11C11/16

摘要： A new read scheme is provided for an MRAM bit having a pinned layer (fixed) and a storage layer (free) sandwiching a nonmagnetic spacer layer. By applying a magnetic field to the bit at least partially orthogonal to the easy axis of the bit, the magnetization direction of the storage layer can be partially rotated or canted without switching the logical state of the MRAM bit. The resistivity of the bit is measured (calculated based on a voltage/current relationship) in two ways: (i) with the magnetization direction of the storage layer partially rotated in a first direction and (ii) with the magnetization direction of the storage layer in its bi-stable orientation parallel to the easy axis. Those measures can then be used to compare and determine the logical state of the storage layer. For instance, if the canted resistivity is greater than the uncanted resistivity then the magnetization directions of the pinned and storage layer are parallel, and if the canted resistivity is less than the uncanted resistivity then the magnetization directions of the pinned and storage layer are opposite.