Method of producing exchange coupling film and method of producing magnetoresistive sensor by using exchange coupling

A method of producing an exchange coupling film comprising an antiferromagnetic layer, a ferromagnetic layer contacting said antiferromagnetic layer at an interface therebetween, and a seed layer comprising a (111) plane of face-centered cubic crystal, which seed layer contacts said antiferromagnetic layer at an interface therebetween on a side opposite said ferromagnetic layer, said antiferromagnetic layer comprising a first antiferromagnetic layer, a second antiferromagnetic layer, and a third antiferromagnetic layer, said method comprising:

• forming said seed layer such that said (111) plane of face-centered cubic crystal is preferentially oriented in a direction parallel to said interface between said seed layer and said antiferromagnetic layer;
• forming said antiferromagnetic layer such that said third antiferromagnetic layer is adjacent to said seed layer, said first antiferromagnetic layer is adjacent to said ferromagnetic layer, and said second antiferromagnetic layer is between said first and said third antiferromagnetic layer, wherein each of said first, said second, and said third antiferromagnetic layers comprises an element X, an element X′, and Mn, wherein X is selected from the group consisting of Pt, Pd, Ir, Rh, Ru, Os, and combinations thereof, and X′ is selected from the group consisting of Ne, Ar, Kr, Xe, Be, B, C, N, Mg, Al, Si, P, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, Cd, Sn, Hf, Ta, W, Re, Au, Pb, a rare earth element, and combinations thereof, such that said second antiferromagnetic layer has a smaller composition ratio of said element X than said first and said third antiferromagnetic layers;
• forming said ferromagnetic layer;
• and
• effecting a heat-treatment, such that an exchange coupling magnetic field is developed at said interface between said antiferromagnetic layer and said ferromagnetic layer.

A method of producing an exchange coupling film comprising an antiferromagnetic layer, a ferromagnetic layer contacting said antiferromagnetic layer at an interface therebetween, and a seed layer comprising a (111) plane of face-centered cubic crystal, which seed layer contacts said antiferromagnetic layer at an interface therebetween on a side opposite said ferromagnetic layer, said antiferromagnetic layer comprising a first antiferromagnetic layer, a second antiferromagnetic layer, and a third antiferromagnetic layer, said method comprising:

• forming said seed layer such that said (111) plane of face-centered cubic crystal is preferentially oriented in a direction parallel to said interface between said seed layer and said antiferromagnetic layer;
• forming said antiferromagnetic layer such that said third antiferromagnetic layer is adjacent to said seed layer, said first antiferromagnetic layer is adjacent to said ferromagnetic layer, and said second antiferromagnetic layer is between said first and said third antiferromagnetic layer, wherein each of said first, said second, and said third antiferromagnetic layers comprise an element X, an element X′, and Mn, wherein said element X is selected from the group consisting of Pt, Pd, Ir, Rh, Ru, Os, and combinations thereof, and wherein said element Xis selected from the group consisting of an element which invades interstices of a space lattice composed of said element X and said Mn, and an element which substitutes for a portion of lattice points of a crystalline lattice constituted by said Mn and said element X, such that said second antiferromagnetic layer has a smaller composition ratio of said element X than said first and said third antiferromagnetic layers;
• and
• effecting a heat-treatment after said forming of said seed layer and said forming of said antiferromagnetic layer, such that an exchange coupling magnetic field is developed at said interface between said antiferromagnetic layer and said ferromagnetic layer.

A method of producing a magnetoresistive sensor comprising:

• forming a seed layer contacting an antiferromagnetic layer at an interface therebetween, said antiferromagnetic layer comprising a first antiferromagnetic layer, a second antiferromagnetic layer and a third antiferromagnetic layer, said seed layer comprising a (111) plane of face-centered cubic crystal, such that said (111) plane of face-centered cubic crystal is preferentially oriented in a direction parallel to said interface between said seed layer and said antiferromagnetic layer;
• forming said antiferromagnetic layer such that said third antiferromagnetic layer is adjacent to said seed layer, said first antiferromagnetic layer is adjacent to a pinned magnetic layer, and said second antiferromagnetic layer is between said first and said third antiferromagnetic layers, wherein each of said first, said second, and said third antiferromagnetic layers comprises an element X and Mn, wherein X is selected from the group consisting of Pt, Pd, Ir, Rh, Ru, Os, and combinations thereof, such that said second antiferromagnetic layer has a smaller composition ratio of said element X than said first and said third antiferromagnetic layers;
• forming said pinned magnetic layer contacting said antiferromagnetic layer at an interface therebetween on a side opposite said seed layer, which pinned magnetic layer has a direction of magnetization fixed by an exchange anisotropic magnetic field with said antiferromagnetic layer;
• forming a non-magnetic intermediate layer between said pinned magnetic layer and a free magnetic layer;
• forming said free magnetic layer;
• forming a bias layer which aligns a direction of magnetization of said free magnetic layer in a direction that intersects said direction of magnetization of said pinned magnetic layer;
• and
• effecting a heat-treatment, such that an exchange coupling magnetic field is developed at said interface between said antiferromagnetic layer and said pinned magnetic layer.

A method of producing a magnetoresistive sensor comprising:

• forming a seed layer contacting an antiferromagnetic layer at an interface therebetween, said antiferromagnetic layer comprising a first antiferromagnetic layer, a second antiferromagnetic layer and a third antiferromagnetic layer, said seed layer comprising a (111) plane of face-centered cubic crystal, such that said (111) plane of face-centered cubic crystal is preferentially oriented in a direction parallel to said interface between said seed layer and said antiferromagnetic layer;
• forming said antiferromagnetic layer such that said third antiferromagnetic layer is adjacent to said seed layer, said first antiferromagnetic layer is adjacent to a pinned magnetic layer, and said second antiferromagnetic layer is between said first and said third antiferromagnetic layer, wherein each of said first, said second, and said third antiferromagnetic layers comprises an element X, an element X′, and Mn, wherein X is selected from the group consisting of Pt, Pd, Ir, Rh, Ru, Os, and combinations thereof, and X′ is selected from the group consisting of Ne, Ar, Kr, Xe, Be, B, C, N, Mg, Al, Si, P, Ti, V, Cr, Fe, Go, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, Cd, Sn, Hf, Ta, W, Re, Au, Pb, a rare earth element, and combinations thereof, such that said second antiferromagnetic layer has a smaller composition ratio of said element X than said first and said third antiferromagnetic layers;
• forming said pinned magnetic layer contacting said antiferromagnetic layer at an interface therebetween on a side opposite said seed layer, which pinned magnetic layer has a direction of magnetization fixed by an exchange anisotropic magnetic field with said antiferromagnetic layer;
• forming a non-magnetic intermediate layer between said pinned magnetic layer and a free magnetic layer;
• forming said free magnetic layer;
• forming a bias layer which aligns a direction of magnetization of said free magnetic layer in a direction that intersects said direction of magnetization of said pinned magnetic layer;
• and
• effecting a heat-treatment, such that an exchange coupling magnetic field is developed at said interface between said antiferromagnetic layer and said pinned magnetic layer.

A method of producing a magnetoresistive sensor comprising:

• forming a seed layer contacting an antiferromagnetic layer at an interface therebetween, said antiferromagnetic layer comprising a first antiferromagnetic layer, a second antiferromagnetic layer and a third antiferromagnetic layer, said seed layer comprising a (111) plane of face-centered cubic crystal, such that said (111) plane of face-centered cubic crystal is preferentially oriented in a direction parallel to said interface between said seed layer and said antiferromagnetic layer;
• forming said antiferromagnetic layer such that said third antiferromagnetic layer is adjacent to said seed layer, said first antiferromagnetic layer is adjacent to a pinned magnetic layer, and said second antiferromagnetic layer is between said first and said third antiferromagnetic layers, wherein each of said first, said second, and said third antiferromagnetic layers comprises an element X and Mn, wherein X is selected from the group consisting of Pt, Pd, Ir, Rh, Ru, Os, and combinations thereof, such that said second antiferromagnetic layer has a smaller composition ratio of said element X than said first and said third antiferromagnetic layers;
• forming said pinned magnetic layer contacting said antiferromagnetic layer at an interface therebetween on a side opposite said seed layer, which pinned magnetic layer has a direction of magnetization fixed by an exchange anisotropic magnetic field with said antiferromagnetic layer;
• forming a non-magnetic intermediate layer between said pinned magnetic layer and a free magnetic layer having an upper side and a lower side;
• forming said free magnetic layer;
• forming an antiferromagnetic exchange bias layer on either said upper side or said lower side of said free magnetic layer, said antiferromagnetic exchange bias layer comprising a plurality of portions spaced from each other in a track width direction;
• and
• effecting a heat-treatment, such that an exchange coupling magnetic field is developed at said interface between said antiferromagnetic layer and said pinned magnetic layer.

A method of producing a magnetoresistive sensor comprising:

• forming a seed layer contacting an antiferromagnetic layer at an interface therebetween, said antiferromagnetic layer comprising a first antiferromagnetic layer, a second antiferromagnetic layer and a third antiferromagnetic layer, said seed layer comprising a (111) plane of face-centered cubic crystal, such that said (111) plane of face-centered cubic crystal is preferentially oriented in a direction parallel to said interface between said seed layer and said antiferromagnetic layer;
• forming said antiferromagnetic layer such that said third antiferromagnetic layer is adjacent to said seed layer, said first antiferromagnetic layer is adjacent to a pinned magnetic layer, and said second antiferromagnetic layer is between said first and said third antiferromagnetic layer, wherein each of said first, said second, and said third antiferromagnetic layers comprises an element X, an element X′, and Mn, wherein X is selected from the group consisting of Pt, Pd, Ir, Rh, Ru, Os, and combinations thereof, and X′ is selected from the group consisting of Ne, Ar, Kr, Xe, Be, B, C, N, Mg, Al, Si, P, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, Cd, Sn, Hf, Ta, W, Re, Au, Pb, a rare earth element, and combinations thereof, such that said second antiferromagnetic layer has a smaller composition ratio of said element X than said first and said third antiferromagnetic layers;
• forming said pinned magnetic layer contacting said antiferromagnetic layer at an interface therebetween on a side opposite said seed layer, which pinned magnetic layer has a direction of magnetization fixed by an exchange anisotropic magnetic field with said antiferromagnetic layer;
• forming a non-magnetic intermediate layer between said pinned magnetic layer and a free magnetic layer having an upper side and a lower side;
• forming said free magnetic layer;
• forming an antiferromagnetic exchange bias layer on either said upper side or said lower side of said free magnetic layer, said antiferromagnetic exchange bias layer comprising a plurality of portions spaced from each other in a track width direction;
• and
• effecting a heat-treatment, such that an exchange coupling magnetic field is developed at said interface between said antiferromagnetic layer and said pinned magnetic layer.

A method of producing a magnetoresistive sensor comprising:

• forming a seed layer comprising a (111) plane of face-centered cubic crystal, such that said (111) plane of face-centered cubic crystal is preferentially oriented in a direction parallel to an interface between said seed layer and a first antiferromagnetic layer;
• forming said first antiferromagnetic layer overlying said seed layer;
• forming a first pinned magnetic layer overlying said first antiferromagnetic layer;
• forming a first non-magnetic layer overlying said first pinned magnetic layer;
• forming a free magnetic layer overlying said first non-magnetic layer;
• forming a second non-magnetic layer overlying said free magnetic layer;
• forming a second pinned magnetic layer overlying said second non-magnetic layer;
• forming a second antiferromagnetic layer overlying said second pinned magnetic layer, said first and second antiferromagnetic layers serving to fix directions of magnetization of said first and second pinned magnetic layers by exchange anisotropic magnetic fields;
• forming a bias layer which aligns a direction of magnetization of said free magnetic layer to a direction that intersects said directions of said first and second pinned magnetic layers;
• and
• effecting a heat-treatment, such that an exchange coupling magnetic field is developed at at least one of a first interface between said first antiferromagnetic layer and said first pinned magnetic layer and a second interface between said second antiferromagnetic layer and said second pinned magnetic layer;
• wherein
• at least one of said first and said second antiferromagnetic layers comprises a first layer, a second layer, and a third layer, wherein each of said first layer, said second layer, and said third layer comprises an element X and Mn, wherein X is selected from the group consisting of Pt, Pd, Ir, Rh, Ru, Os, and combinations thereof, such that said second layer has a smaller composition ratio of said element X than said first and said third layers.

A method of producing a magnetoresistive sensor comprising:

• forming a seed layer comprising a (111) plane of face-centered cubic crystal, such that said (111) plane of face-centered cubic crystal is preferentially oriented in a direction parallel to an interface between said seed layer and a first antiferromagnetic layer;
• forming a first antiferromagnetic layer overlying said seed layer;
• forming a first pinned magnetic layer overlying said first antiferromagnetic layer;
• forming a first non-magnetic layer overlying said first pinned magnetic layer;
• forming a free magnetic layer overlying said first non-magnetic layer;
• forming a second non-magnetic layer overlying said free magnetic layer;
• forming a second pinned magnetic layer overlying said second non-magnetic layer;
• forming a second antiferromagnetic layer overlying said second pinned magnetic layer, said first and second antiferromagnetic layers serving to fix directions of magnetization of said first and said second pinned magnetic layers by exchange anisotropic magnetic fields;
• forming a bias layer which aligns a direction of magnetization of said free magnetic layer to a direction that intersects said directions of said first and said second pinned magnetic layers;
• and
• effecting a heat-treatment, such that an exchange coupling magnetic field is developed at at least one of a first interface between said first antiferromagnetic layer and said first pinned magnetic layer and a second interface between said second antiferromagnetic layer and said second pinned magnetic layer;
• wherein
• at least one of said first and said second antiferromagnetic layers comprises a first layer, a second layer, and a third layer, wherein each of said first layer, said second layer, and said third layer comprises an element X, an element X′, and Mn, wherein X is selected from the group consisting of Pt, Pd, Ir, Rh, Ru, Os, and combinations thereof, and X′ is selected from the group consisting of Ne, Ar, Kr, Xe, Be, B, C, N, Mg, Al, Si, P, Ti, V, Cr, Fe, Go, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, Cd, Sn, Hf, Ta, W, Re, Au, Pb, a rare earth element, and combinations thereof, such that said second layer has a smaller composition ratio of said element X than said first and said third layers.

A method of producing a magnetoresistive sensor comprising:

• forming a magnetoresistive layer having an upper side and a lower side;
• forming a soft magnetic layer, said magnetoresistive layer and said soft magnetic layer being superposed through the intermediacy of a non-magnetic layer;
• forming said non-magnetic layer;
• forming an antiferromagnetic layer on said upper side or said lower side of said magnetoresistive layer, said antiferromagnetic layer comprising a first antiferromagnetic layer, a second antiferromagnetic layer and a third antiferromagnetic layer, and said antiferromagnetic layer comprising a plurality of portions spaced apart in a track width direction, wherein each of said first, said second, and said third antiferromagnetic layers comprises an element X and Mn, wherein X is selected from the group consisting of Pt, Pd, Ir, Rh, Ru, Os, and combinations thereof, such that said second antiferromagnetic layer has a smaller composition ratio of said element X than said first and said third antiferromagnetic layers;
• forming a seed layer contacting said antiferromagnetic layer at an interface therebetween, said seed layer comprising a (111) plane of face-centered cubic crystal, such that said (111) plane of face-centered cubic crystal is preferentially oriented in a direction parallel to said interface between said seed layer and said antiferromagnetic layer;
• and
• effecting a heat-treatment, such that an exchange coupling magnetic field is developed.

A method of producing a magnetoresistive sensor comprising:

• forming a magnetoresistive layer having an upper side and a lower side;
• forming a soft magnetic layer, said magnetoresistive layer and said soft magnetic layer being superposed through the intermediacy of a non-magnetic layer;
• forming said non-magnetic layer;
• forming an antiferromagnetic layer on said upper side or said lower side of said magnetoresistive layer, said antiferromagnetic layer comprising a first antiferromagnetic layer, a second antiferromagnetic layer and a third antiferromagnetic layer, and said antiferromagnetic layer comprising a plurality of portions spaced apart in a track width direction, wherein each of said first, said second, and said third antiferromagnetic layers comprises an element X, an element X′, and Mn, wherein X is selected from the group consisting of Pt, Pd, Ir, Rh, Ru, Os, and combinations thereof, and X′ is selected from the group consisting of Ne, Ar, Kr, Xe, Be, B, C, N, Mg, Al, Si, P, Ti, V, Cr, Fe, Go, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, Cd, Sn, Hf, Ta, W, Re, Au, Pb, a rare earth element, and combinations thereof, such that said second antiferromagnetic layer has a smaller composition ratio of said element X than said first and said third antiferromagnetic layers;
• forming a seed layer contacting said antiferromagnetic layer at an interface therebetween, said seed layer comprising a (111) plane of face-centered cubic crystal, such that said (111) plane of face-centered cubic crystal is preferentially oriented in a direction parallel to said interface between said seed layer and said antiferromagnetic layer;
• and
• effecting a heat-treatment, such that an exchange coupling magnetic field is developed.