Method and system for providing a magnetic junction having an engineered barrier layer
A magnetic junction usable in a magnetic memory and a method for providing the magnetic memory are described. The method includes providing a pinned layer, providing an engineered nonmagnetic tunneling barrier layer, and providing a free layer. The pinned layer and the free layer each include at least one ferromagnetic layer. The engineered nonmagnetic tunneling barrier layer has a tuned resistance area product. In some aspects, the step of providing the engineered nonmagnetic tunneling barrier layer further includes radio-frequency depositing a first oxide layer, depositing a metal layer, and oxidizing the metal layer to provide a second oxide.
1. A method for fabricating a magnetic junction usable in a magnetic memory comprising:
providing a pinned layer including at least one ferromagnetic layer;
providing an engineered nonmagnetic tunneling barrier layer, the engineered nonmagnetic tunneling barrier layer having a tuned resistance area product, the step of providing the engineered nonmagnetic tunneling barrier layer further including
depositing a first metal insertion layer wherein the first metal insertion layer is a non-magnetic metal insertion layer;
radio-frequency depositing a first oxide layer on the first metal insertion layer;
depositing a metal layer; and
oxidizing the metal layer to provide a second oxide layer, the first oxide layer and the second oxide layer being on the first metal insertion layer, the method being free of an oxidation step between the step of depositing the first metal insertion layer and at least one of depositing the metal layer and radio-frequency depositing the first oxide layer; and
providing a free layer including at least an additional ferromagnetic layer, the nonmagnetic tunneling barrier layer residing between the pinned layer and the free layer, the free layer configured to be switchable between a plurality of stable magnetic states when a write current is passed through the magnetic junction.
2. The method of claim 1 wherein the step of providing the engineered nonmagnetic tunneling barrier layer further includes:
depositing a second metal insertion layer, the first oxide layer and the second oxide layer residing between the first metal insertion layer and the second metal insertion layer.
3. The method of claim 2 wherein the first oxide layer adjoins the first insertion layer.
4. The method of claim 2 wherein the second oxide layer adjoins the first insertion layer.
5. The method of claim 2 wherein the step of providing the engineered nonmagnetic tunneling barrier layer further includes oxidizing the second metal insertion layer.
6. The method of claim 2 further comprising:
providing a nonmagnetic layer, the free layer residing between the nonmagnetic layer and the engineered tunneling barrier layer; and
providing an additional pinned layer, the nonmagnetic layer residing between the additional pinned layer and the free layer.
7. The method of claim 6 wherein the nonmagnetic layer is an additional engineered nonmagnetic tunneling barrier layer having an additional tuned resistance area product.
8. The method of claim 2 further comprising:
providing a plurality of contacts including a first contact and a second contact for the magnetic junction.
9. The method of claim 2 wherein the pinned layer is a synthetic antiferromagnet (SAF) including a plurality of ferromagnetic layers separated by a nonmagnetic separation layer, the plurality of ferromagnetic layers being antiferromagnetically aligned.
10. The method of claim 2 wherein the free layer is a synthetic antiferromagnet (SAF) including a plurality of ferromagnetic layers separated by a nonmagnetic separation layer, the plurality of ferromagnetic layers being antiferromagnetically aligned.
11. A method for magnetic memory comprising:
providing a plurality of magnetic memory cells, each of the plurality of magnetic memory cells including at least one magnetic memory element and at least one selection device, the step of providing the at least one magnetic memory element further including
providing a pinned layer for each of the at least one magnetic memory element, the pinned including at least one ferromagnetic layer;
providing an engineered nonmagnetic tunneling barrier layer for each of the at least one magnetic memory element, the engineered nonmagnetic tunneling barrier layer having a tuned resistance area product, the step of providing the engineered nonmagnetic tunneling barrier layer further including
depositing a first metal insertion layer wherein the first metal insertion layer is a non-magnetic metal insertion layer;
radio-frequency depositing a first oxide layer;
depositing a metal layer; and
oxidizing the metal layer to provide a second oxide layer, the first oxide layer and the second oxide layer being on the first metal insertion layer, the method being free of an oxidation step between the step of depositing the first metal insertion layer and at least one of depositing the metal layer and radio-frequency depositing the first oxide layer; and
providing a free layer for each of the at least one magnetic memory element, the free layer including at least an additional ferromagnetic layer, the nonmagnetic tunneling barrier layer residing between the pinned layer and the free layer, the free layer configured to be switchable between a plurality of stable magnetic states when a write current is passed through the magnetic memory element of the plurality of magnetic memory elements;
providing at least one bit line coupled with the plurality of magnetic memory cells; and
providing at least one word line coupled with the plurality of magnetic memory cells.
12. The method of claim 11 wherein the step of providing the engineered nonmagnetic tunneling barrier layer further includes:
depositing a second metal insertion layer, the first oxide layer and the second oxide layer residing between the first metal insertion layer and the second metal insertion layer.
13. The method of claim 12 wherein the first oxide layer adjoins the first insertion layer.
14. The method of claim 12 wherein the second oxide layer adjoins the first insertion layer.
15. The method of claim 12 wherein the step of providing the engineered nonmagnetic tunneling barrier layer further includes oxidizing at least one of the first metal insertion layer and the second metal insertion layer.
16. The method of claim 12 wherein the step of providing the at least one magnetic memory element further includes:
providing a nonmagnetic layer, the free layer residing between the nonmagnetic layer and the engineered tunneling barrier layer; and
providing an additional pinned layer, the nonmagnetic layer residing between the additional pinned layer and the free layer.
17. The method of claim 16 wherein the nonmagnetic layer is an additional engineered nonmagnetic tunneling barrier layer having an additional tuned resistance area product.
18. The method of claim 12 further comprising:
providing a plurality of contacts, each of the plurality of magnetic memory elements having a first contact and a second contact of the plurality of contacts.
19. The method of claim 12 wherein the pinned layer is a synthetic antiferromagnet (SAF) including a plurality of ferromagnetic layers separated by a nonmagnetic separation layer, the plurality of ferromagnetic layers being antiferromagnetically aligned.
20. The method of claim 12 wherein the free layer is a synthetic antiferromagnet (SAF) including a plurality of ferromagnetic layers separated by a nonmagnetic separation layer, the plurality of ferromagnetic layers being antiferromagnetically aligned.