Tunnel magnetoresistive effect element and magnetic memory
A TMR element includes a reference layer, a magnetization free layer, a tunnel barrier layer between the reference layer and the magnetization free layer, and a perpendicular magnetization inducing layer and a leakage layer stacked on a side of the magnetization free layer opposite to the tunnel barrier layer side. A magnetization direction of the reference layer is fixed along a stack direction. The perpendicular magnetization inducing layer imparts magnetic anisotropy along the stack direction to the magnetization free layer. The leakage layer is disposed on an end portion region in an in-plane direction of the magnetization free layer. The perpendicular magnetization inducing layer is disposed on at least a central region in the in-plane direction of the magnetization free layer. A resistance value of the leakage layer along the stack direction per unit area in plane is less than that of the perpendicular magnetization inducing layer.
1. A magnetic memory comprising:
a tunnel magnetoresistive effect element as a storage element, wherein the tunnel magnetoresistive effect element comprises:
a reference layer;
a magnetization free layer;
a tunnel barrier layer stacked in a stack direction between the reference layer and the magnetization free layer;
a perpendicular magnetization inducing layer and a leakage layer stacked on a side of the magnetization free layer opposite to the tunnel barrier layer side wherein a bottom surface of the leakage layer is in physical contact with a portion of a top surface of the magnetization free layer;
a side wall portion formed of an insulation material and covering side surfaces of the reference layer, the tunnel barrier layer, the magnetization free layer, the perpendicular magnetization inducing layer, and the leakage layer, and
a mask layer formed of a conductive material and stacked on the perpendicular magnetization inducing layer and the leakage layer,
wherein a magnetization direction of the reference layer is fixed along the stack direction,
the perpendicular magnetization inducing layer imparts magnetic anisotropy along the stack direction to the magnetization free layer,
the leakage layer is disposed on an end portion region in an in-plane direction of the magnetization free layer,
the perpendicular magnetization inducing layer is disposed on at least a central region in the in-plane direction of the magnetization free layer,
a resistance value of the leakage layer along the stack direction per unit area in plane is less than a resistance value of the perpendicular magnetization inducing layer along the stack direction per unit area in plane,
the perpendicular magnetization inducing layer and the leakage layer are arranged along the in-plane direction of the magnetization free layer,
in a cross section parallel to the stack direction, a width in an in-plane direction of the leakage layer is greater than a thickness of the perpendicular magnetization inducing layer, and
the perpendicular magnetization inducing layer is configured such that a resistance value of the perpendicular magnetization inducing layer along the stack direction per unit area in a plane perpendicular to the stack direction is smaller than that of the tunnel barrier layer.
2. A built-in memory comprising:
the magnetic memory according to claim 1 .