MRAM top electrode structure with liner layer
A semiconductor device is provided. The semiconductor device includes a memory including a bottom electrode, a magnetic tunnel junction (MTJ) stack on the bottom electrode, and an upper electrode on the MTJ stack. The semiconductor device also includes at least one dielectric layer formed around the memory, wherein a top metal layer contact hole is formed in the at least one dielectric layer, a dielectric liner layer formed in the top metal contact hole, and a top metal layer contact in the top metal layer contact hole.
1. A method of manufacturing a semiconductor device, the method comprising:
forming a memory by
forming a bottom electrode,
forming a magnetic tunnel junction (MTJ) stack on the bottom electrode, and
forming an upper electrode on the MTJ stack;
forming at least one dielectric layer around the memory;
forming a top metal layer contact hole in the at least one dielectric layer, the top metal layer contact hole formed to a depth sufficient to expose at least a portion of a sidewall of the MTJ stack;
after forming the top metal layer contact hole, forming a dielectric liner layer in the top metal contact hole;
removing at least substantially horizontal portions of the dielectric liner layer; and
forming a top metal layer contact in the top metal layer contact hole.
2. The method according to claim 1 , wherein the dielectric liner layer covers at least a portion of a sidewall of the MTJ stack.
3. The method according to claim 1 , wherein forming the at least one dielectric layer includes forming a dielectric encapsulation layer and a dielectric fill layer.
4. The method according to claim 1 , wherein the MTJ stack includes a reference layer, a tunnel barrier layer, and a magnetic free layer.
5. The method according to claim 1 , wherein the dielectric liner layer covers sidewalls of the upper electrode.
6. The method according to claim 1 , wherein a width of the top metal contact hole is greater than a width of the upper electrode.
7. The method according to claim 1 , wherein at least a portion of the dielectric liner layer is between the top metal contact and the MTJ stack.
8. The method according to claim 1 , wherein the top metal contact is in direct contact with at least an upper surface of the upper electrode.
9. The method according to claim 1 , wherein the dielectric liner layer comprises AlN.
10. A semiconductor device comprising:
a memory including
a bottom electrode,
a magnetic tunnel junction (MTJ) stack on the bottom electrode, and
an upper electrode on the MTJ stack;
at least one dielectric layer formed around the memory, wherein a top metal layer contact hole is included in the at least one dielectric layer, the top metal layer contact hole extending to a depth to at least partially expose a sidewall of the MTJ stack;
a dielectric liner layer formed in the top metal contact hole that covers at least the partially exposed sidewall of the MTJ stack; and
a top metal layer contact in the top metal layer contact hole.
11. The semiconductor device according to claim 10 , wherein the dielectric liner layer covers at least a portion of a sidewall of the MTJ stack.
12. The semiconductor device according to claim 10 , wherein the top metal contact hole is formed to a depth sufficient to expose at least a portion of a sidewall of the MTJ stack.
13. The semiconductor device according to claim 10 , wherein the at least one dielectric layer includes a dielectric encapsulation layer and a dielectric fill layer.
14. The semiconductor device according to claim 10 , wherein the MTJ stack includes a reference layer, a tunnel barrier layer, and a magnetic free layer.
15. The semiconductor device according to claim 10 , wherein the dielectric liner layer covers sidewalls of the upper electrode.
16. The semiconductor device according to claim 10 , wherein a width of the top metal contact hole is greater than a width of the upper electrode.
17. The semiconductor device according to claim 10 , wherein at least a portion of the dielectric liner layer is between the top metal contact and the MTJ stack.
18. The semiconductor device according to claim 10 , wherein the top metal contact is in direct contact with at least an upper surface of the upper electrode.
19. The semiconductor device according to claim 10 , wherein the dielectric liner layer comprises AlN.