Patent ID: 7816719

Claim:
A nonvolatile magnetic memory device comprising a magnetoresistance device having a recording layer formed of a ferromagnetic material for storing information by use of variation in resistance depending on the magnetization inversion state; wherein: a plan-view shape of said recording layer includes four sides; two of said four sides each include a smooth curve; said plan-view shape of said recording layer is inscribed in a virtual rhombus having four sides corresponding to the four sides of the recording layer, the plan-view shape of the recording layer is a superposed shape in which a first shape and a second shape have a center coinciding with the center of the first shape at one position, a longer axis, and a shorter axis orthogonally intersecting said longer axis at the bisecting point of said longer axis, said longer axis being substantially parallel to an easy axis of magnetization of said recording layer, and said shorter axis being substantially parallel to a hard axis of magnetization of said recording layer; each of said two of said four sides of said recording layer that includes a respective smooth curve contacts the corresponding side of said virtual rhombus at least two points; each of the other two of said four sides of said recording layer includes a straight line that contacts the corresponding side of said virtual rhombus at more than two points; said sides constituting said plan-view shape of said recording layer are smoothly connected to each other, and the plan-view shape of the recording layer is inscribed in the virtual rhombus in a pseudo-rhombic shape to minimize dispersion of the switching magnetic field and to enlarge a data writing margin of the magnetoresistance device.