Method of fabricating a magnetic stack design with decreased substrate stress
View Patent ↗A magnetic element and a method for making a magnetic element. The method includes patterning a first electrode material to form a first electrode on a substrate and depositing filler material on the substrate around the first electrode. The method further includes polishing to form a planar surface of filler and the first electrode. A magnetic cell is formed on the planar surface and a second electrode is formed on the magnetic cell. In some embodiments, the first electrode has an area that is at least 2:1 to the area of the magnetic cell.
1. A method of making a magnetic element comprising:
patterning a first electrode material to form a first electrode on a substrate, wherein patterning the first electrode material to form a first electrode comprises patterning the first electrode material to form a dog-bone shaped first electrode;
depositing filler on the substrate around the first electrode;
polishing to form a planar surface comprising the filler and the first electrode; and
forming a magnetic cell on the planar surface and a second electrode on the magnetic cell.
2. The method of claim 1 wherein depositing filler comprises depositing dielectric filler comprising SiO 2 , Al 2 O 3 , FSG (fluorinated silicate glass), doped SiO 2 , SiN or MgO.
3. The method of claim 1 wherein the first electrode material and the second electrode material comprise TiN, TaN, Cu or W.
4. The method of claim 3 wherein patterning a first electrode material comprises patterning a first electrode material with a thickness of about 1000 Å.
5. The method of claim 1 wherein polishing comprises chemical-mechanical polishing (CMP).
6. The method of claim 1 wherein forming a magnetic cell comprises forming a magnetic cell comprising a first ferromagnetic layer having a pinned magnetization orientation, a second ferromagnetic layer having a switchable magnetization orientation, and a non-magnetic layer therebetween.
7. The method of claim 6 wherein forming a magnetic cell comprises forming a magnetic cell having a thickness of about 600 Å.
8. The method of claim 6 wherein forming a magnetic cell comprises providing a magnetic cell layer and etching the layer to form the magnetic cell.
9. The method of claim 8 wherein etching the magnetic cell layer comprises ion beam etching (IBE) or reactive-ion etching (RIE).
10. The method of claim 1 wherein forming a second electrode comprises forming a second electrode having a thickness of about 2000 Å.
11. The method of claim 1 further comprising deposing a spacer layer over the second electrode and polishing the spacer layer to form a planar surface.
12. The method of claim 1 wherein the dumbbell shaped first electrode has a width at least twice a width of the magnetic cell.
13. The method of claim 1 wherein:
patterning a first electrode material to form a first electrode comprises forming the first electrode with an aspect ratio, and
forming a magnetic cell comprises forming the magnetic cell with an aspect ratio, wherein the aspect ratio of the magnetic cell is the same as the aspect ratio of the first electrode.