Magnetic memory devices for differential sensing
A magnetic memory device is provided. The magnetic memory device includes a first magnetic tunnel junction (MTJ) stack, a second MTJ stack, and a spin-orbit torque (SOT) electrode. The second MTJ stack is adjacent to the first MTJ stack. The SOT electrode is connected to the first MTJ stack and the second MTJ stack, wherein the SOT electrode has a first electrode section along a first axis and a second electrode section along a second axis, and the second axis is spaced apart from and parallel to the first axis.
1 . A magnetic memory device, comprising:
a first magnetic tunnel junction (MTJ) stack;
a second MTJ stack adjacent to the first MTJ stack;
a spin-orbit torque (SOT) electrode connected to the first MTJ stack and the second MTJ stack, wherein the SOT electrode has a first electrode section along a first axis and a second electrode section along a second axis, the second axis is spaced apart from and parallel to the first axis; and
a connecting electrode section along a third axis substantially perpendicular to the first axis and the second axis, wherein the first axis and the second axis extend away from the third axis in opposite directions.
2 . The magnetic memory device of claim 1 , the connecting electrode section comprises a first end portion connecting to the first electrode section and a second end portion connected to the second electrode section.
3 . The magnetic memory device of claim 2 , wherein the first MTJ stack is in contact with the first electrode section and the second MTJ stack is in contact with the second electrode section.
4 . The magnetic memory device of claim 2 , wherein the first MTJ stack at a corner of the SOT electrode where the first electrode section connects to the connecting electrode section.
5 . The magnetic memory device of claim 4 , wherein the second MTJ stack is at a corner of the SOT electrode where the second electrode section connects to the connecting electrode section.
6 . The magnetic memory device of claim 1 , wherein the first MTJ stack and the second MTJ stack each comprise a tunneling barrier layer between a free magnetic layer and a fixed magnetic layer, wherein the magnetization direction of the fixed magnetic layers of the first MTJ stack and the second MTJ stack are aligned in a substantially similar direction.
7 . The magnetic memory device of claim 6 , further comprising a magnetic element, and a magnetic field direction of the magnetic element is substantially parallel to the first axis.
8 . The magnetic memory device of claim 1 , wherein the magnetic memory device includes a magnetic random-access memory (MRAM) comprising three transistors and two MTJ stacks.
9 . The magnetic memory device of claim 8 , wherein the magnetic memory device is capable of storing one true bit in the first MTJ stack and one complementary bit in the second MTJ stack.
10 . A magnetic memory device, comprising:
a first magnetic tunnel junction (MTJ) stack;
a first transistor coupled to the first MTJ stack;
a second MTJ stack adjacent to the first MTJ stack;
a second transistor coupled to the second MTJ stack;
a spin-orbit torque (SOT) electrode connected to the first MTJ stack and the second MTJ stack, wherein the SOT electrode has a first electrode section along a first axis, a second electrode section along a second axis, the second axis is spaced apart from and parallel to the first axis, and a connecting electrode section along a third axis substantially perpendicular to the first axis and the second axis, wherein the first axis and the second axis extend away from the third axis in opposite directions; and
a third transistor coupled to the SOT electrode.
11 . The magnetic memory device of claim 10 , further comprising a first bit line and a second bit line, wherein the first bit line is coupled to the first transistor and the second transistor, and the second bit line is coupled to the third transistor.
12 . The magnetic memory device of claim 11 , further comprising a source line, wherein the source line is coupled to the SOT electrode.
13 . The magnetic memory device of claim 12 , further comprising a first word line and a second word line, wherein the first word line is coupled to the third transistor and the second word line is coupled to the first transistor and the second transistor.
14 . The magnetic memory device of claim 13 , wherein the first word line serves as an electrical route for a write operation of the magnetic memory device.
15 . The magnetic memory device of claim 14 , wherein the second word line serves as an electrical route for a read operation of the magnetic memory device.
16 . A method of forming a magnetic memory device, comprising:
forming a first magnetic tunnel junction (MTJ) stack and a second MTJ stack; and
forming a spin-orbit torque (SOT) electrode including forming a first electrode section, forming a second electrode section, and forming a connecting electrode section, wherein the first electrode section is formed along a first axis, the second electrode section is formed along a second axis that is spaced apart from and parallel to the first axis, and the connecting electrode section is formed along a third axis that is substantially perpendicular to the first axis and the second axis, wherein the first axis and the second axis extend away from the third axis in opposite directions.
17 . The method of claim 16 , wherein the connecting electrode section comprises a first end portion and a second end portion, and forming the connecting electrode section comprises forming the first end portion to be connected to the first electrode section and the second end portion to be connected to the second electrode section.
18 . The method of claim 16 , further comprising forming a first bit line coupled to the first MTJ stack and a second bit line coupled to the second MTJ stack and the SOT electrode.
19 . The method of claim 18 , further comprising forming a first word line coupled to the SOT electrode and a second word line coupled to the first MTJ stack and the second MTJ stack.