Magnetoresistive random access memory and method of making the same
A magnetoresistive random access memory (MRAM) cell includes a magnetic tunnel junction (MTJ), a top electrode disposed over the MTJ, a bottom electrode disposed below the MTJ, and an induction line disposed to one side of the MTJ. The induction line is configured to induce a perpendicular magnetic field at the MTJ.
1. A magnetoresistive random access memory (MRAM) cell, comprising:
a magnetic tunnel junction (MTJ);
a top electrode disposed over the MTJ;
a bottom electrode disposed below the MTJ; and
an induction line disposed to one side of the MTJ,
wherein the induction line is configured to induce a perpendicular magnetic field at the MTJ.
2. The MRAM cell of claim 1 , wherein the induction line is formed in the same layer as the top electrode.
3. The MRAM cell of claim 1 , wherein the induction line is formed in the same layer as the bottom electrode.
4. The MRAM cell of claim 1 , wherein the induction line is formed in the same layer as the MTJ.
5. The MRAM cell of claim 1 , wherein the MTJ comprises a free layer, a fixed layer, and an insulator disposed between the free layer and the fixed layer, the fixed layer has a fixed magnetic polarity, and the free layer has a changeable magnetic polarity.
6. The MRAM cell of claim 5 wherein the free layer comprises CoFeB or NiFe.
7. The MRAM cell of claim 5 , wherein the fixed layer comprises CoFe or CoFeB.
8. The MRAM cell of claim 5 wherein the insulator comprises MgO or Al 2 O 3 .
9. The MRAM cell of claim 1 , wherein the MTJ has an oval or elliptic shape.
10. The MRAM cell of claim 1 , wherein the MRAM cell is a spin transfer torque (STT) MRAM cell.
11. A method of fabricating a magnetoresistive random access memory (MRAM) cell, comprising:
forming a bottom electrode over a substrate;
forming a magnetic tunnel junction (MTJ) over the bottom electrode;
forming a top electrode over the MTJ; and
forming an induction line disposed to one side of the MTJ, wherein the induction line is configured to induce a perpendicular magnetic field at the MTJ.
12. The method of claim 11 , wherein the induction line is formed in the same layer as the top electrode.
13. The method of claim 11 , wherein the induction line is formed in the same layer as the bottom electrode.
14. The method of claim 11 , wherein the induction line is formed in the same layer as the MTJ.
15. The method of claim 11 , wherein forming the MTJ comprises:
forming a fixed layer having a fixed magnetic polarity over the bottom electrode;
forming an insulator over the fixed layer; and
forming a free layer over the insulator having a Changeable magnetic polarity.
16. The method of claim 15 , wherein the free layer comprises CoFeB or NiFe.
17. The method of claim 15 , wherein the fixed layer comprises CoFe or CoFeB.
18. The method of claim 15 , wherein the insulator comprises MgO or Al 2 O 3 .
19. A magnetoresistive random access memory (MRAM) cell, comprising:
a magnetic tunnel junction (MTJ) including a free layer, a fixed layer, and an insulator disposed between the free layer and the fixed layer, wherein the fixed layer has a fixed magnetic polarity, and the free layer has a changeable magnetic polarity;
a top electrode disposed over the MTJ;
a bottom electrode disposed below the MTJ; and
an induction line disposed to one side of the MTJ,
wherein the induction line is configured to induce a perpendicular magnetic field at the MTJ and the MTJ has an oval or elliptic shape.
20. The MRAM cell of claim 19 , wherein the MTJ is above a via.