MAGNETORESISTIVE MEMORY DEVICE AND METHOD OF MANUFACTURING MAGNETORESISTIVE MEMORY DEVICE
According to an embodiment, a magnetoresistive memory device includes a layer stack. The layer stack includes a first ferromagnet, an insulator on the first ferromagnet, and a second ferromagnet on the insulator. A nonmagnet is provided above the layer stack. A first conductor is provided on the nonmagnet. A hard mask is provided above the first conductor. The nonmagnet includes a material that is removed at a first etching rate against a first ion beam. The first conductor includes a material that is removed at a second etching rate against the first ion beam. The first etching rate is lower than the second etching rate.
1 . A magnetoresistive memory device comprising:
a layer stack including a first ferromagnet, an insulator on the first ferromagnet, and a second ferromagnet on the insulator;
a nonmagnet above the layer stack;
a first conductor on the nonmagnet; and
a hard mask above the first conductor, wherein
the nonmagnet comprises a material that is removed at a first etching rate against a first ion beam,
the first conductor comprises a material that is removed at a second etching rate against the first ion beam, and
the first etching rate is lower than the second etching rate.
2 . The device according to claim 1 , wherein:
a side face of the nonmagnet consists with a face different from an extended face of a side face of the layer stack.
3 . The device according to claim 2 , wherein:
a side face of the first conductor consists a face different from an extended face of a side face of the nonmagnet.
4 . The device according to claim 2 , wherein:
the nonmagnet comprises one of tantalum, tungsten, hafnium, iron, cobalt, aluminum, and molybdenum.
5 . The device according to claim 4 , wherein:
the first conductor comprises one of platinum, tungsten, tantalum, and ruthenium.
6 . The device according to claim 2 , wherein:
the nonmagnet comprises one boride of tantalum, tungsten, hafnium, iron, cobalt, aluminum, and molybdenum.
7 . The device according to claim 6 , wherein:
the first conductor comprises one of platinum, tungsten, tantalum, and ruthenium.
8 . The device according to claim 1 , wherein:
the nonmagnet comprises one of tantalum, tungsten, hafnium, iron, cobalt, aluminum, and molybdenum.
9 . The device according to claim 5 , wherein:
the first conductor comprises one of platinum, tungsten, tantalum, and ruthenium.
10 . The device according to claim 1 , wherein:
the nonmagnet comprises one boride of tantalum, tungsten, hafnium, iron, cobalt, aluminum, and molybdenum.
11 . The device according to claim 10 , wherein:
the first conductor comprises one of platinum, tungsten, tantalum, and ruthenium. 10
12 . A method of manufacturing a magnetoresistive memory device, the method comprising:
forming a first layer stack above a substrate, the first layer stack comprising a first ferromagnet, an insulator above the first ferromagnet, a second ferromagnet above the insulator, a nonmagnet above the second ferromagnet, and a first conductor above the nonmagnet;
forming a hard mask having an opening on the first layer stack;
irradiating, through the opening, the first layer stack with a first ion beam traveling at a first angle with respect to a normal to the substrate, the nonmagnet being etched at a first etching rate by the first ion beam, the first conductor being etched at a second etching rate by the first ion beam, and the first etching rate being lower than the second etching rate; and
irradiating, through the opening, the first layer stack with a second ion beam traveling at a second angle with respect to the normal to the substrate, the second angle being smaller than the first angle.
13 . The method according to claim 12 , wherein:
the nonmagnet comprises one of tantalum, tungsten, hafnium, iron, cobalt, aluminum, and molybdenum.
14 . The method according to claim 13 , wherein:
the first conductor comprises one of platinum, tungsten, tantalum, and ruthenium.
15 . The method according to claim 12 , wherein:
the nonmagnet comprises one boride of tantalum, tungsten, hafnium, iron, cobalt, aluminum, and molybdenum.
16 . The method according to claim 13 , wherein:
the first conductor comprises one of platinum, tungsten, tantalum, and ruthenium.