MAGNETORESISTIVE MEMORY DEVICE
A magnetoresistive memory device includes a first magnetic layer having a variable magnetization direction; a second magnetic layer, a magnetization direction of the second magnetic layer being invariable; a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer; and a second nonmagnetic layer provided on the first magnetic layer, which is opposite the first nonmagnetic layer. The first magnetic layer having a stacked layer structure in which amorphous magnetic material layer is sandwiched between crystalline magnetic material layers.
1 . A magnetoresistive memory device comprising:
a first magnetic layer having a variable magnetization direction;
a second magnetic layer, a magnetization direction of the second magnetic layer being invariable;
a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer; and
a second nonmagnetic layer provided on the first magnetic layer, which is opposite the first nonmagnetic layer,
the first magnetic layer having a stacked layer structure in which amorphous magnetic material layer is sandwiched between crystalline magnetic material layers.
2 . The device of claim 1 , further comprising nonmagnetic material layers provided between one of the crystalline magnetic material layers and the amorphous magnetic material layer, and between the other crystalline magnetic layer and the amorphous magnetic material layer, respectively.
3 . A magnetoresistive memory device comprising:
a first magnetic layer having a variable magnetization direction;
a second magnetic layer, a magnetization direction of the second magnetic layer being invariable;
a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer;
a second nonmagnetic layer provided on the first magnetic layer, which is opposite the first nonmagnetic layer; and
an amorphous Mo layer provided on the second nonmagnetic layer, which is opposite the first magnetic layer.
4 . The device of claim 1 , wherein a first electrode is provided on a semiconductor substrate, and the first magnetic layer is disposed closer to the first electrode than the second magnetic layer.
5 . The device of claim 1 , wherein a first electrode is provided on a semiconductor substrate, and the second magnetic layer is disposed closer to the first electrode than the first magnetic layer.
6 . The device of claim 3 , wherein a first electrode is provided on a semiconductor substrate, and the first magnetic layer is disposed closer to the first electrode than the second magnetic layer.
7 . The device of claim 3 , wherein a first electrode is provided on a semiconductor substrate, and the second magnetic layer is disposed closer to the first electrode than the first magnetic layer.
8 . A magnetoresistive memory device comprising:
a bottom electrode;
a first magnetic layer provided on the bottom electrode, a magnetization direction of the first magnetic layer being invariable;
a first nonmagnetic layer provided on the first magnetic layer;
a second magnetic layer provided on the first nonmagnetic layer, a magnetization direction of the second magnetic layer being variable, the second magnetic layer including Mo;
a second nonmagnetic layer provided on the second magnetic layer; and
an upper electrode provided on the second nonmagnetic layer.
9 . The device of claim 8 , wherein:
the first magnetic layer is a reference layer having magnetic anisotropy perpendicular to a film surface;
the second magnetic layer is a storage layer having magnetic anisotropy perpendicular to a film surface; and
the first nonmagnetic layer is a tunnel barrier layer through which a tunneling current flows.
10 . The device of claim 8 , wherein the second nonmagnetic layer comprises MgO.
11 . The device of claim 8 , wherein the first and the second nonmagnetic layers are different materials.
12 . The device of claim 8 , wherein the second magnetic layer includes Fe or Co.
13 . The device of claim 8 , wherein the second magnetic layer has a stacked layer structure in which a middle layer including Mo is provided between magnetic material layers.
14 . The device of claim 8 , wherein the second nonmagnetic layer is an oxide.
15 . The device of claim 8 , further comprising a first layer provided between the bottom electrode and the first magnetic layer.
16 . The device of claim 15 , wherein the first layer includes at least one element selected from the group consisting of Al, Be, Mg, Ca, Sr, Ba, Sc, Y, La, Si, Zr, Hf, W, Cr, Mo, Nb, Ti, Ta, and V, or a boride of these elements.