论文部分内容阅读
Freescale所提供的MRAM替代性方案在Freescale的器件中,自由的和固定的磁体层并不是单纯的铁磁板。相反,它们是合成的反铁磁体(synthetic antiferromagnet,SAF)三明治结构,由两个反向对准的铁磁材料层以及两层材料之间所夹的一层非磁性材料耦合隔层而组成。图2示出了一个SAF位单元。SAF三明治结构产生磁致电阻效应的能力并不会因为它的混合式结构而受到影响。对准和反对准只取决于MTJ结构两侧相对的两层材料。将两层板材组成SAF,就可以让每层板变成“磁矩平衡”—净外磁场为零。这避免了磁场交叠而导致的可扩展性的问题。
MRAM Alternatives Provided by Freescale In Freescale devices, the free and fixed magnet layers are not mere ferromagnetic plates. Instead, they are synthetic synthetic antiferromagnet (SAF) sandwich structures consisting of two oppositely aligned layers of ferromagnetic material and a layer of nonmagnetic coupling material sandwiched between two layers of material. Figure 2 shows a SAF bit cell. The ability of the SAF sandwich structure to produce a magnetoresistance effect is not affected by its hybrid structure. Alignment and opposition are based only on two opposing layers of material on either side of the MTJ structure. By combining the two layers of SAF, it is possible to make each of the plates “magnetic moment balanced” - the net external magnetic field is zero. This avoids the problem of scalability caused by magnetic field overlap.