Amorphous alloys for magnetic devices
AssigneeFreescale Semiconductor, Inc.
InventorsJon M. Slaughter, Renu W. Dave, Srinivas V. Pietambaram
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Abstract
An amorphous layer of a cobalt iron-based (CoFe-based) magnetic alloy suitable for use in magnetoelectronic devices is disclosed. In the most preferred embodiments of the present invention, at least one amorphous layer is provided in an MTJ stack to increase the smoothness of the various layers in the MTJ stack while also enhancing the magnetic performance of the resulting device. Additionally, the alloys of the present invention are also useful in cladding applications to provide electrical flux containment for signal lines in magnetoelectronic devices and as a material for fabricating write heads.
Claims15
A magnetic tunnel junction comprising:
- a first ferromagnetic layer;
- a spacer layer formed over said first ferromagnetic layer;
- a second ferromagnetic layer formed over said spacer layer;
- wherein at least one of said first ferromagnetic layer and said second ferromagnetic layer is an amorphous (Co100-X FeX)100-YDY alloy comprising X in a range of approximately 10.5%-25% by atomic %;
- and
- wherein D comprises at least one of boron (B), tantalum (Ta), hafnium (Hf), boron-carbon(B—C), tantalum-carbon (Ta—C) and hafnium-carbon (Hf—C).
A magnetoresistive sensor comprising:
- a first ferromagnetic layer, said first ferromagnetic layer comprising a fixed magnetic moment;
- a spacer layer formed on said first ferromagnetic layer;
- a second ferromagnetic layer formed on said spacer layer, said second ferromagnetic layer comprising a free magnetic moment with an easy axis approximately perpendicular to said fixed magnetic moment of said first ferromagnetic layer;
- wherein at least one of said first ferromagnetic layer and said second ferromagnetic layer is an amorphous (Co100-X FeX)100-YDY alloy comprising X is in a range of approximately 10.5%-25% by atomic %;
- and
- wherein D comprises at least one of boron (B), tantalum (Ta), hafnium (Hf), boron-carbon (B—C). tantalum-carbon (Ta—C) and hafnium-carbon (Hf—C).
Dependencies are inferred from the claim text.