MTJ spin hall MRAM bit-cell and array
An apparatus is described having a select line and an interconnect with Spin Hall Effect (SHE) material. The interconnect is coupled to a write bit line. A transistor is coupled to the select line and the interconnect. The transistor is controllable by a word line. The apparatus also includes an MTJ device having a free magnetic layer coupled to the interconnect.
1. An apparatus comprising:
a select line;
an interconnect with Spin Hall Effect (SHE) material, the interconnect coupled to a write bit line;
a transistor coupled to the select line and the interconnect, the transistor controllable by a word line; and
a Magnetic Tunnel Junction (MTJ) device having a free magnetic layer coupled to the interconnect, the MTJ device comprising free and fixed magnetic layers and a tunneling material between the free and fixed magnetic layers.
2. The apparatus of claim 1 , wherein one end of the MTJ device is coupled to a read bit line.
3. The apparatus of claim 2 , wherein the MTJ device is physically located between the read bit line and the write bit line, and wherein the read bit line, the write bit line, and the select line are parallel to one another and flowing in the same direction.
4. The apparatus of claim 1 , wherein the select line is formed on a zero metal (M 0 ) layer.
5. The apparatus of claim 1 , wherein the read bit line is formed on a fourth metal (M 4 ) layer, and wherein the write bit line is formed on a second metal (M 2 ) layer.
6. The apparatus of claim 1 , wherein the MTJ device is operable to increase its resistance during read operation, and wherein the MTJ device is operable to decrease its resistance during write operation.
7. The apparatus of claim 1 , wherein the interconnect is exclusive to a single MTJ device.
8. The apparatus of claim 1 , wherein the transistor is a single transistor and the MTJ device is a single MTJ device.
9. The apparatus of claim 8 , wherein the single transistor is formed from multiple diffusions or shared diffusion such that a channel region of the transistor behaves as two or more transistors in parallel.
10. A method comprising:
forming a transistor having source region, drain region, and gate region;
forming a select line in metal zero (M 0 );
coupling the select line to the source region of the transistor;
forming an interconnect with Spin Hall Effect (SHE) material;
coupling the interconnect to a first metal (M 1 ) layer and to the drain terminal of the transistor; and
coupling a word line to the gate region of the transistor;
forming an MTJ device comprising free and fixed magnetic layers and a tunneling material between the free and fixed magnetic layers, the MTJ device being coupled to the interconnect.
11. The method claim 10 further comprising:
forming a write bit line in a second metal (M 2 ) layer; and
coupling the write bit line to the interconnect, wherein the MTJ device is physically located between the read bit line and the write bit line, and wherein the read bit line, the write bit line, and the select line are parallel to one another and flowing in the same direction.
12. The method of claim 11 further comprising:
forming the Magnetic Tunnel Junction (MTJ) device in a region dedicated for a third metal (M 3 ) layer; and
coupling the free magnetic layer of the MTJ device to the interconnect.
13. The method of claim 12 further comprising:
forming a read bit line in a fourth metal (M 4 ) layer; and
coupling the read bit line to the MTJ device, wherein the MTJ device is physically located between the read bit line and the write bit line, and wherein the read bit line, the write bit line, and the select line are parallel to one another and flowing in the same direction.
14. The method of claim 10 further comprising:
forming the Magnetic Tunnel Junction (MTJ) device in a region dedicated for a second metal (M 2 ) layer; and
coupling the free magnetic layer of the MTJ device to the interconnect.
15. The method of claim 14 further comprising:
forming a read bit line in a fourth metal (M 4 ) layer; and
coupling the read bit line to the MTJ device via a third metal (M 3 ) layer.
16. The method of claim 10 , wherein the interconnect is exclusive to a single MTJ device.
17. An apparatus comprising:
a plurality of select lines;
a plurality of write bit lines;
a plurality of interconnects with Spin Hall Effect (SHE) material; and
a plurality of rows of transistors, wherein transistors in each row are coupled to one of a select line of the plurality of select lines, wherein each interconnect of the plurality of interconnects in a row of transistors is coupled to one of the write bit lines; and,
a plurality of MTJ devices respectively coupled to the plurality of interconnects, each of the MTJ devices comprising free and fixed magnetic layers and a tunneling material between the free and fixed magnetic layers.
18. The apparatus of claim 17 further comprises:
a plurality of read bit lines; and
a plurality of rows of the Magnetic Tunnel Junction (MTJ) devices each having its free magnetic layer coupled to one of the interconnects, wherein each interconnect is indirectly coupled to each other.
19. The apparatus of claim 18 , wherein each of the plurality of read bit lines is coupled to a row of the MTJ devices from among the plurality of rows of MTJ devices.
20. The apparatus of claim 18 , wherein each of the MTJ devices is operable to increase its resistance during read operation, and wherein each of the MTJ devices is operable to decrease its resistance during write operation.