Magnetic enhancement layer in memory cell
Magnetic memory cell comprising two conductors and a magnetic storage element between the two conductors, wherein a magnetic enhancement layer (MEL) is provided in the proximity of at least along a partial length of at least one of the two conductors. The MEL is for enhancing a magnetic field in the element when the two conductors are energized. Methods for operation and fabrication process for the memory cell are also disclosed. The memory cell is particularly for use in magnetic random access memory (MRAM) circuits, when using magnetic tunnel junction (MTJ) stacks as the magnetic storage elements.
1. A method of manufacturing a magnetic memory cell comprising a first conductor, a second conductor, and a magnetic storage element disposed between said two conductors, comprising:
depositing a magnetic enhancement layer proximate at least along a partial length of at least one of said two conductors, said magnetic enhancement layer for enhancing a magnetic field in said element when said first and second conductors are energized; and wherein the magnetic enhancement layer at least partially encapsulates the first and second conductors.
2. The method of claim 1 , wherein said magnetic enhancement layer comprises a stack of tantalum/nickel-iron/tantalum, and wherein said nickel-iron is in any form that produces ferromagnetic properties.
3. The method of claim 1 , wherein said magnetic enhancement layer is on opposite sides of said first and second conductors.
4. The method of claim 1 , further comprising masklessly etching back said magnetic enhancement layer while retaining said magnetic enhancement layer only at said opposite sides.
5. The method of claim 1 wherein said first conductor is a word line and said second conductor is a bit line.
6. The method of claim 1 wherein at least one of said two conductors comprises aluminum.
7. The method of claim 1 wherein said magnetic enhancement layer comprises at least one of the following ferromagnetic materials:
a) iron,
b) cobalt,
c) iron-cobalt, and
d) nickel-iron,
wherein iron-cobalt and nickel-iron are in any form that produce ferromagnetic properties.
8. The memory cell of claim 1 wherein said magnetic enhancement layer comprises a first ferromagnetic material for said first conductor and a second ferromagnetic material for said second conductor.