Method and processing apparatus for fabricating a magnetic resistive random access memory device
Methods of fabricating MRAM devices are provided along with a processing apparatus for fabricating the MRAM devices. The methods may include forming a ferromagnetic layer, cooling the ferromagnetic layer to a temperature within a range of between about 50° K to about 300° K, forming and oxidizing one or more Mg layers on the cooled ferromagnetic layer to form an MgO structure, forming a free layer on the MgO structure, and forming a capping layer on the free layer.
1. A method of fabricating a magnetic resistive random access memory (MRAM) device, the method comprising:
forming a lower electrode on a substrate;
forming a seed layer on the lower electrode;
forming a pinning layer including a CoPt-based layer or CoPd-based layer;
forming a synthetic anti-ferromagnetic (SAF) layer on the pinning layer;
forming a pinned layer including a CoFe-based layer; on the SAF layer;
cooling the substrate having the pinned layer exposed thereon to a range of approximately between about 50° K to about 300° K;
forming a first Mg layer on the pinned layer, after the cooling of the substrate having the pinned layer;
forming a first MgO layer by oxidizing the first Mg layer;
forming a second Mg layer on the first MgO layer;
forming a second MgO layer by oxidizing the second Mg layer, wherein the first and second MgO layers collectively form an MgO structure;
forming a free layer on the MgO structure;
forming a capping layer on the free layer; and
forming an upper electrode on the capping layer.
2. The method of claim 1 ,
wherein the seed layer comprises at least one of Ta or Ru.
3. The method of claim 2 ,
wherein the seed layer comprises a lower Ta layer and an upper Ru layer stacked on the lower Ta layer.
4. The method of claim 1 ,
wherein the pinning layer having a hexagonal closest packing (HCP) structure.
5. The method of claim 1 ,
wherein the pinning layer comprises a stacked layer of Co/Pt or Co/Pd having a face center cubic (FCC) structure or FCC-like structures.
6. The method of claim 1 ,
wherein the SAF layer comprises Ru.
7. The method of claim 1 ,
wherein the pinned layer comprises CoFeB.
8. The method of claim 7 ,
wherein the pinned layer comprises one of multilayer structures including CoFeB/Ta/CoFeB, Co/B/CoFeB, or Co/W/CoFeB/W/CoFeB.
9. The method of claim 1 ,
wherein the free layer comprises a single layer including CoFeB, or a multilayer including CoFeB/W/CoFeB.
10. The method of claim 1 ,
wherein the capping layer comprises a metal including Ta.
11. The method of claim 1 , further comprising:
forming a third Mg layer between the second MgO layer and the free layer; and
forming a third MgO layer by oxidizing the third Mg layer.
12. The method of claim 11 ,
wherein the first MgO layer, the second MgO layer, and the third MgO layer are unified to be materially contiguous with each other.
13. The method of claim 11 , further comprising:
cooling the second MgO layer before forming the third Mg layer thereon.
14. The method of claim 1 , further comprising:
cooling the first MgO layer before forming the second Mg layer thereon.
15. A method of fabricating an MRAM device, the method comprising:
forming a lower electrode on a substrate;
forming a seed layer having Ta and Ru on a lower electrode;
forming a pinning layer including a Co-based layer on the seed layer;
forming an SAF layer on the pinning layer;
forming a pinned layer including an CoFe-based layer on the SAF layer;
cooling the substrate having the pinned layer exposed thereon to a range of approximately between about 50° K to about 300° K;
forming a first Mg layer on the pinned layer, after the cooling of the substrate having the pinned layer;
forming a first MgO layer by oxidizing the first MgO layer;
forming a second Mg layer on the first MgO layer;
forming a second MgO layer by oxidizing the second Mg layer;
forming a free layer having CoFeB on the second MgO layer;
forming a capping layer having Ta on the free layer; and
forming an upper electrode on the capping layer.