MAGNETORESISTIVE MEMORY DEVICE AND MANUFACTURING METHOD OF THE SAME
According to one embodiment, a magnetoresistive memory device includes an electrode, a first layer which is provided on the electrode and includes an amorphous portion in at least a part of an electrode side, and a magnetoresisive element provided on the first layer.
1 . A magnetoresistive memory device comprising:
an electrode;
a first layer which is provided on the electrode and includes an amorphous portion in at least a part of an electrode side; and
a magnetoresistive element provided on the first layer.
2 . The device of claim 1 , further comprising
a second layer provided between the first layer and the magnetoresistive element, wherein
the first layer contains at least one of Zr, Hf and Ta as a base material, and contains at least one of B and C as an additive, and
a concentration of the additive on a second layer side in the first layer is less than a concentration of the additive on an the electrode side in the first layer.
3 . The device of claim 1 , wherein
the first layer includes a crystalline portion on a magnetoresistive element side.
4 . The device of claim 2 , wherein
the concentration of the additive in the first layer is changed continuously in a thickness direction of the first layer.
5 . The device of claim 2 , wherein
the concentration of the additive in the first layer is changed in a stepwise manner in a thickness direction of the first layer.
6 . The device of claim 2 , wherein
the second layer is crystalline.
7 . The device of claim 1 , wherein
a size of a bottom surface of the electrode is different from a size of an upper surface of the first layer.
8 . The device of claim 1 , wherein
the first layer comprises a first conductive layer provided on the electrode side, and a second conductive layer provided on the first conductive layer,
the first and second conductive layers contain at least one of B and C as an additive, and
a concentration of B or C in the first conductive layer is higher than a concentration of B or C in the second conductive layer.
9 . The device of claim 8 , wherein
the first and second conductive layers contain at least one of Zr, Hf and Ta as a base material.
10 . The device of claim 8 , wherein
the concentration of B or C in the first or second conductive layer is constant in a thickness direction of the first and second conductive layers.
11 . The device of claim 8 , wherein
the concentration of B or C in the first or second conductive layer is changed continuously in a thickness direction of the first and second conductive layers.
12 . The device of claim 8 , wherein
the first conductive layer is amorphous, and the second conductive layer and the second layer are crystalline.
13 . The device of claim 1 , wherein
the magnetoresistive element has a stacked layer structure comprising a first magnetic layer, a second magnetic layer and a nonmagnetic layer provided, between the first and second magnetic layers.
14 . The device of claim 13 , wherein
the first magnetic layer or the second magnetic layer includes a crystalline substance.
15 . The device of claim 1 , further comprising
a substrate on which a transistor for switching is provided, wherein
the electrode is provided on the substrate and is connected to a part of the transistor.
16 . A method of manufacturing a magnetoresistive memory device, the method comprising:
forming a first layer on an electrode, the first layer containing at least one of Zr, Hf and Ta as a base material, containing at least one of B and C as an additive, and containing the additive more on an electrode side than on an opposite side of the electrode;
forming a second layer on the first layer; and
forming a magnetoresistive element, on the second layer.
17 . The method of claim 16 , wherein
the first layer is amorphous on the electrode side, the first layer is crystalline on a second layer side, and
the second layer is crystalline.
18 . The method of claim 16 , wherein
a concentration of the additive in the first layer is changed continuously or in a stepwise manner in a thickness direction of the first layer.
19 . The method of claim 16 , wherein
the forming the first layer includes forming a first conductive layer on the electrode, and forming a second conductive layer on the first conductive layer, and
the second conductive layer contains the additive less than the first conductive layer.