Apparatus for initializing perpendicular MRAM device
View Patent ↗The present invention is directed to an apparatus for initializing perpendicular magnetic tunnel junction. The apparatus comprises a permanent magnet for generating a magnetic flux; a flux concentrator made of a soft ferromagnetic material and having a base area in contact with the permanent magnet and an tip area that is smaller than the base area, thereby funneling and concentrating the magnetic flux to the tip area for emitting a magnetic field therefrom; and a means for supporting and conveying a substrate with an arrays of magnetic tunnel junctions formed therein to traverse the magnetic field in close proximity to the tip area. The apparatus may further include at least one of the following: a substrate heater, a flux containment structure coupled to the permanent magnet, and a magnetic imaging plate disposed in proximity to the substrate on the opposite side from the flux concentrator.
1. An apparatus for initializing perpendicular magnetic tunnel junctions, the apparatus comprising:
a permanent magnet;
a flux concentrator made of a soft ferromagnetic material and having a base area in contact with said permanent magnet and an tip area that is smaller than said base area, thereby funneling and concentrating a magnetic flux generated by said permanent magnet to form a magnetic field at said tip area; and
a means for supporting and conveying a substrate to traverse said magnetic field in close proximity to said tip area.
2. The apparatus of claim 1 , wherein said soft ferromagnetic material comprises at least one metal selected from the group consisting of cobalt, nickel, and iron.
3. The apparatus of claim 1 , further comprising a means for adjusting relative distance between said tip area and a surface of said substrate.
4. The apparatus of claim 1 , further comprising a substrate heater.
5. The apparatus of claim 1 , further comprising a flux containment structure made of a soft ferromagnetic material and coupled to said permanent magnet.
6. The apparatus of claim 1 , further comprising a magnetic imaging layer made of a soft ferromagnetic material disposed in proximity to said means for supporting and conveying said substrate opposite said flux concentrator.
7. The apparatus of claim 1 , further comprising a magnetic imaging layer made of a soft ferromagnetic material disposed in proximity to said substrate opposite said flux concentrator.
8. The apparatus of claim 5 , further comprising a magnetic imaging layer made of a soft ferromagnetic material in proximity to said substrate opposite said flux concentrator.
9. The apparatus of claim 8 , wherein each of said flux concentrator, said magnetic imaging layer, and said flux containment structure is made of a soft ferromagnetic material comprising at least one metal selected from the group consisting of cobalt, nickel, and iron.
10. The apparatus of claim 8 , further comprising a flux closure structure coupled to said magnetic imaging layer and said flux containment structure.
11. The apparatus of claim 10 , wherein said flux closure structure is made of a soft ferromagnetic material comprising at least one metal selected from the group consisting of cobalt, nickel, and iron.
12. An apparatus for initializing perpendicular magnetic tunnel junctions, the apparatus comprising:
a first permanent magnet;
a first flux concentrator having a first base area in contact with said first permanent magnet and a first tip area that is smaller than said first base area;
a second permanent magnet;
a second flux concentrator having a second base area in contact with said second permanent magnet and a second tip area that is smaller than said second base area, said first and second tip areas being spaced apart and facing each other with a magnetic field formed therebetween; and
a means for supporting and conveying a substrate to traverse said magnetic field.
13. The apparatus of claim 12 , wherein said first and second tip areas have opposite magnetic polarities.
14. The apparatus of claim 12 , further comprising a substrate heater.
15. The apparatus of claim 12 , further comprising a first flux containment structure coupled to said first permanent magnet and a second flux containment structure coupled to said second permanent magnet.
16. The apparatus of claim 15 , wherein each of said first and second flux concentrators and said first and second flux containment structures is made of a soft ferromagnetic material.
17. The apparatus of claim 15 , further comprising a flux closure structure coupled to said first and second flux containment structures.
18. The apparatus of claim 17 , wherein said flux closure structure is made of a soft ferromagnetic material comprising at least one metal selected from the group consisting of cobalt, nickel, and iron.