Magnetic memory device having a recording layer
View Patent ↗There is provided a magnetic memory device stable in write characteristics. The magnetic memory device has a recording layer. The planar shape of the recording layer has the maximum length in the direction of the easy-axis over a primary straight line along the easy-axis, and is situated over a length smaller than the half of the maximum length in the direction perpendicular to the easy-axis, and on the one side and on the other side of the primary straight line respectively, the planar shape has a first part situated over a length in the direction perpendicular to the easy-axis, and a second part situated over a length smaller than the length in the direction perpendicular to the easy-axis. The outer edge of the first part includes only a smooth curve convex outwardly of the outer edge.
1. A magnetic memory device, comprising:
a substrate;
a first wire arranged over the substrate, and having a part extending with a first axis as the central axis along the first axis;
a second wire arranged over the substrate, having a part extending along a second axis as the central axis crossing with the first axis, and crossing with the first wire with a space in the direction of thickness of the substrate provided therebetween; and
a recording layer having a planar shape, placed so as to be at least partially interposed between the first wire and the second wire in the region in which the first wire and the second wire cross each other with the space provided therebetween, having an easy-axis, and being changed in magnetization direction by the synthetic magnetic field of the magnetic field by the first wire and the magnetic field by the second wire,
wherein the planar shape has the maximum length in the direction of the easy-axis over a primary straight line along the easy-axis, and the planar shape has a width smaller than half of the maximum length in the direction perpendicular to the easy-axis, and
on one side and on the other side of the primary straight line respectively, the planar shape has a first part having a first length in the direction perpendicular to the easy-axis, and a second part having a second length smaller than the first length in the direction perpendicular to the easy-axis, and
wherein the outer edge of the first part includes only a smooth curve convex outwardly of the outer edge, and
the second part has a concave part in the edge of the planar shape.
2. The magnetic memory device according to claim 1 , wherein the first part has a symmetry axis perpendicular to the easy-axis.
3. The magnetic memory device according to claim 2 , wherein the second part has asymmetry with respect to the symmetry axis.
4. The magnetic memory device according to claim 1 , wherein the curve is a quadratic curve.
5. The magnetic memory device according to claim 1 , wherein the middle point of the part included in the planar shape of the primary straight line is, in a plan view, situated at the point of intersection between the first axis and the second axis.