Low cost anti-parallel pinned spin valve (SV) and magnetic tunnel junction (MTJ) structures with high thermal stability
View Patent ↗The invention is a laminated antiferromagnetically coupled (AFC) structure for use in a spin valve (SV) sensor or magnetic tunnel junction (MTJ) device, having two ferromagnetic films coupled together with an improved AFC film. Particularly the AFC film comprises an alloy material selected from the group consisting of Ru 100-x m x , Os 100-y m y , Ir 100-y m y , Rh 100-y ,m y , Re 100-z m z , and M 100-x m x , where M is an alloy of two or more materials selected from the group consisting of Ru, Os, Ir, Rh, and Re, and where m is a material selected from the group consisting of W, Ta, Mo, Nb and alloys of two or more materials selected from W, Ta, Mo, and Nb, and where x is between approximately 5 and 95 at. %, y is between approximately 10 and 90 at. %, and z is between approximately 25 and 75 at. %. The sensors may be used in magnetic heads of hard disk drives.
1. A magnetic head including a magnetoresistive sensor comprising:
a pinned ferromagnetic layer structure;
a free ferromagnetic layer structure; and
a nonmagnetic spacer layer located between the pinned and free ferromagnetic layers structures; and wherein at least one of the pinned and free ferromagnetic layers structure includes:
first and second ferromagnetic films;
an antiferromagnetic coupling (AFC) film located between and in contact with said first and second ferromagnetic films, said AFC film comprising an alloy material selected from the group consisting of Ru 100-x m x , Os 100-y m y , Ir 100-y m y , Rh 100-y ,m y , Re 100-z m z , and M 100-x m x , where M is an alloy of two or more materials selected from the group consisting of Ru, Os, Ir, Rh, and Re, and where m is a material selected from the group consisting of W, Ta, Mo, Nb and alloys of two or more materials selected from W, Ta, Mo, and Nb, and where x is between approximately 5 and 95 at. %, y is between approximately 10 and 90 at. %, and z is between approximately 25 and 75 at. %.
2. A magnetic head as described in claim 1 wherein said AFC film has a thickness from approximately 3 Å to approximately 30 Å.
3. A magnetic head as described in claim 1 wherein said pinned ferromagnetic layer structure includes NiFe/X/NiFe, NiCo/X/NiFe, CoFe/X/NiFe, NiFe/X/NiCo, NiFe/X/CoFe or CoFe/X/CoFe, where X consists of said AFC film.
4. A magnetic head as described in claim 1 wherein said free ferromagnetic layer structure includes NiFe/X/NiFe, NiCo/X/NiFe, CoFe/X/NiFe, NiFe/X/NiCo, NiFe/X/CoFe or CoFe/X/CoFe, where X consists of said AFC film.
5. A magnetic head as described in claim 1 wherein both said pinned ferromagnetic layer structure and said free ferromagnetic layer structure include first and second ferromagnetic films having said AFC film formed therebetween.
6. A hard disk drive including a magnetic head magnetic head including a magnetoresistive sensor comprising:
a pinned ferromagnetic layer structure;
a free ferromagnetic layer structure; and
a nonmagnetic spacer layer located between the pinned and free ferromagnetic layers structures; and wherein at least one of the pinned and free ferromagnetic layers structure includes:
first and second ferromagnetic films;
an antiferromagnetic coupling (AFC) film located between and in contact with said first and second ferromagnetic films, said AFC film having a thickness sufficient to couple said first and second ferromagnetic films together with their magnetic moments oriented antiparallel to one another; said AFC film comprising an alloy material selected from the group consisting of Ru 100-x m x , Os 100-y m y , Ir 100-y m y , Rh 100-y ,m y , Re 100-z m z , and M 100-x m x , where M is an alloy of two or more materials selected from the group consisting of Ru, Os, Ir, Rh, and Re, and where m is a material selected from the group consisting of W, Ta, Mo, Nb and alloys of two or more materials selected from W, Ta, Mo, and Nb, and where x is between approximately 5 and 95 at. %, y is between approximately 10 and 90 at. %, and z is between approximately 25 and 75 at. %.
7. A hard disk drive including a magnetic head magnetic head as described in claim 6 wherein said AFC film has a thickness from approximately 3 Å to approximately 30 Å.
8. A hard disk drive including a magnetic head magnetic head as described in claim 6 wherein said pinned ferromagnetic layer structure includes NiFe/X/NiFe, NiCo/X/NiFe, CoFe/X/NiFe, NiFe/X/NiCo, NiFe/X/CoFe or CoFe/X/CoFe, where X consists of said AFC film.
9. A hard disk drive including a magnetic head magnetic head as described in claim 6 wherein said free ferromagnetic layer structure includes NiFe/X/NiFe, NiCo/X/NiFe, CoFe/X/NiFe, NiFe/X/NiCo, NiFe/X/CoFe or CoFe/X/CoFe, where X consists of said AFC film.
10. A hard disk drive including a magnetic head magnetic head as described in claim 6 wherein both said pinned ferromagnetic layer structure and said free ferromagnetic layer structure include first and second ferromagnetic films having said AFC film formed therebetween.
11. A laminated ferromagnetic layer structure, comprising:
first and second ferromagnetic films;
an antiferromagnetic coupling (AFC) film located between and in contact with said first and second ferromagnetic films, said AFC film comprising an alloy material selected from the group consisting of Ru 100-x n x , where n is a material selected from the group consisting of W, Mo, Nb and alloys of two or more materials selected from the group consisting of W, Ta, Mo and Nb, and Os 100-y m y , Ir 100-y m y , Rh 100-y ,m y , Re 100-z m z , and M 100-x m x , where M is an alloy of two or more materials selected from the group consisting of Ru, Os, Ir, Rh, and Re, and where m is a material selected from the group consisting of W, Ta, Mo, Nb and alloys of two or more materials selected from W, Ta, Mo, and Nb, and where x is between approximately 5 and 95 at. %, y is between approximately 10 and 90 at. %, and z is between approximately 25 and 75 at. %.
12. A laminated ferromagnetic layer structure as described in claim 11 wherein said AFC film has a thickness from approximately 3 Å to approximately 30 Å.
13. A laminated ferromagnetic layer structure as described in claim 11 wherein said ferromagnetic layer structure includes NiFe/X/NiFe, NiCo/X/NiFe, CoFe/X/NiFe, NiFe/X/NiCo, NiFe/X/CoFe or CoFe/X/CoFe, where X consists of said AFC film.
14. A spin valve sensor structure, comprising:
a pinned ferromagnetic layer structure;
a free ferromagnetic layer structure; and
a nonmagnetic, electrically conductive spacer layer located between the pinned and free ferromagnetic layers structures; and wherein at least one of the pinned and free ferromagnetic layers structure includes:
first and second ferromagnetic films;
an antiferromagnetic coupling (AFC) film located between and in contact with said first and second ferromagnetic films, said AFC film comprising an alloy material selected from the group consisting of Ru 100-x m x , Os 100-y m y , Ir 100-y m y , Rh 100-y ,m y , Re 100-z m z , and M 100-x m x , where M is an alloy of two or more materials selected from the group consisting of Ru, Os, Ir, Rh, and Re, and where m is a material selected from the group consisting of W, Ta, Mo, Nb and alloys of two or more materials selected from W, Ta, Mo, and Nb, and where x is between approximately 5 and 95 at. %, y is between approximately 10 and 90 at. %, and z is between approximately 25 and 75 at. %.
15. A spin valve sensor structure as described in claim 14 wherein said AFC film has a thickness from approximately 3 Å to approximately 30 Å.
16. A spin valve sensor structure as described in claim 14 wherein said pinned ferromagnetic layer structure includes NiFe/X/NiFe, NiCo/X/NiFe, CoFe/X/NiFe, NiFe/X/NiCo, NiFe/X/CoFe or CoFe/X/CoFe, where X consists of said AFC film.
17. A spin valve sensor structure as described in claim 14 wherein said free ferromagnetic layer structure includes NiFe/X/NiFe, NiCo/X/NiFe, CoFe/X/NiFe, NiFe/X/NiCo, NiFe/X/CoFe or CoFe/X/CoFe, where X consists of said AFC film.
18. A spin valve sensor structure as described in claim 14 wherein both said pinned ferromagnetic layer structure and said free ferromagnetic layer structure include first and second ferromagnetic films having said AFC film formed therebetween.
19. A magnetic tunnel junction structure, comprising:
a pinned ferromagnetic layer structure;
a free ferromagnetic layer structure; and
a nonmagnetic, electrically insulative spacer layer located between the pinned and free ferromagnetic layers structures; and wherein at least one of the pinned and free ferromagnetic layers structure includes:
first and second ferromagnetic films;
an antiferromagnetic coupling (AFC) film located between and in contact with said first and second ferromagnetic films, said AFC film comprising an alloy material selected from the group consisting of Ru 100-x m x , Os 100-y m y , Ir 100-y m y , Rh 100-y ,m y , Re 100-z m z , and M 100-x m x , where M is an alloy of two or more materials selected from the group consisting of Ru, Os, Ir, Rh, and Re, and where m is a material selected from the group consisting of W, Ta, Mo, Nb and alloys of two or more materials selected from W, Ta, Mo, and Nb, and where x is between approximately 5 and 95 at. %, y is between approximately 10 and 90 at. %, and z is between approximately 25 and 75 at. %.
20. A magnetic tunnel junction structure as described in claim 19 wherein said AFC film has a thickness from approximately 3 Å to approximately 30 Å.
21. A magnetic tunnel junction structure as described in claim 19 wherein said pinned ferromagnetic layer structure includes NiFe/X/NiFe, NiCo/X/NiFe, CoFe/X/NiFe, NiFe/X/NiCo, NiFe/X/CoFe or CoFe/X/CoFe, where X consists of said AFC film.
22. A magnetic tunnel junction structure as described in claim 19 wherein said free ferromagnetic layer structure includes NiFe/X/NiFe, NiCo/X/NiFe, CoFe/X/NiFe, NiFe/X/NiCo, NiFe/X/CoFe or CoFe/X/CoFe, where X consists of said AFC film.
23. A magnetic tunnel junction structure as described in claim 19 wherein both said pinned ferromagnetic layer structure and said free ferromagnetic layer structure include first and second ferromagnetic films having said AFC film formed therebetween.