Spin valve sensor free layer structure with a cobalt based layer that promotes magnetic stability and high magnetoresistance

A method of making a magnetic read head, which includes a spin valve sensor comprising the steps of:

• a making of the spin valve sensor comprising the steps of:
• forming a free layer structure that has a magnetic moment and an easy axis;
• forming a ferromagnetic pinned layer structure that has a magnetic moment;
• forming a pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
• forming a nonmagnetic conductive spacer layer between the free layer structure and the pinned layer structure;
• forming the free layer structure by obliquely ion beam sputtering at least one cobalt or cobalt based layer in the presence of a magnetic field oriented in a direction of said easy axis;
• the pinning layer structure being formed by forming a nickel oxide (NiO) layer and an alpha iron oxide (αFeO) layer wherein each of the nickel oxide (NiO) layer and the alpha iron oxide (αFeO) layer has been formed by oblique ion beam sputtering at angles α and β wherein angles α and β form first and second planes respectively which are orthogonal with respect to one another.

A method of making a magnetic read head, which includes a spin valve sensor, comprising the steps of:

• forming the spin valve sensor as follows:
• forming a ferromagnetic pinned layer structure that has a magnetic moment;
• forming a pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
• forming a nonmagnetic conductive spacer layer between the free layer structure and the pinned layer structure;
• and
• forming the pinning layer structure of a nickel oxide (NiO) layer and an alpha iron oxide (αFeO) layer wherein at least one of the nickel oxide (NiO) layer and the alpha iron oxide (αFeO) layer has been obliquely ion beam sputtered at angles α and β wherein angles α and β form first and second planes respectively which are orthogonal with respect to one another.

A method of making a magnetic read head, which includes a spin valve sensor, comprising:

• a making of the spin valve sensor including the steps of:
• forming a free layer structure that has a magnetic moment and an easy axis;
• forming a ferromagnetic pinned layer structure that has a magnetic moment;
• forming a pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
• forming a nonmagnetic conductive spacer layer between the free layer structure and the pinned layer structure;
• a making the free layer structure including the steps of:
• obliquely ion beam sputtering first and second cobalt or cobalt based layers and a nickel iron based layer in the presence of a magnetic field oriented in a direction of said easy axis with the first and second cobalt or cobalt based layers interfacing the spacer layer and a cap layer respectively and the nickel iron based layer being located between and interfacing the first and second cobalt or cobalt based layers;
• the oblique ion beam sputtering being at angles α=40° and β=10°-30° wherein angles α and β form first and second planes respectively which are orthogonal with respect to one another;
• and
• after said oblique ion beam sputtering in the presence of said field oriented in said direction of the easy axis, annealing each of the cobalt or cobalt based layers and the nickel iron based layer.

A method of making magnetic head assembly that includes a write head and a read head, comprising the steps of:

• a making of the write head including:
• forming ferromagnetic first and second pole piece layers in pole tip, yoke and back gap regions wherein the yoke region is located between the pole tip and back gap regions;
• forming a nonmagnetic nonconductive write gap layer between the first and second pole piece layers in the pole tip region;
• forming an insulation stack with at least one coil layer embedded therein between the first and second pole piece layers in the yoke region;
• and
• connecting the first and second pole piece layers at said back gap region, and making the read head as follows:
• forming a spin valve sensor and first and second nonmagnetic first and second read gap layers with the spin valve sensor located between the first and second read gap layers;
• forming a ferromagnetic first shield layer;
• and
• forming the first and second read gap layers between the first shield layer and the first pole piece layer;
• and
• a making of the spin valve sensor comprising the steps of:
• forming a free layer structure that has a magnetic moment and an easy axis;
• forming a ferromagnetic pinned layer structure that has a magnetic moment;
• forming a pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
• forming a nonmagnetic conductive spacer layer between the free layer structure and the pinned layer structure;
• a making of the free layer structure including the step of:
• obliquely ion beam sputtering first and second cobalt or cobalt based layers and a nickel iron based layer in the presence of a magnetic field oriented in a direction of said easy axis with the first and second cobalt or cobalt based layers interfacing the spacer layer structure and a gap layer respectively and the nickel iron based layer being located between and interfacing the first and second cobalt or cobalt based layers;
• the oblique ion beam sputtering being at angles α=40° and β=10°-30° wherein angles α and β form first and second planes respectively which are orthogonal with respect to one another;
• and
• after said oblique ion beam sputtering in the presence of said field oriented in said direction of the easy axis, annealing each of the cobalt or cobalt based layers and the nickel iron based layer.

A method of making a magnetic layer and/or an antiferromagnetic (AFM) layer for an electrical device comprising the steps of:

• obliquely ion beam sputtering at least one material layer from a target onto a substrate to form said magnetic layer and/or antiferromagnetic (AFM) layer;
• the oblique ion beam sputtering being at angles α and β wherein each angle α and β is acute and wherein the angles α and β form first and second planes respectively which are orthogonal with respect to each other;
• and
• the angle β being 10° to 30°.

A method of making a magnetic layer and/or an antiferromagnetic (AFM) layer for an electrical device comprising the steps of:

• obliquely ion beam sputtering at least one material layer from a target onto a substrate to form said magnetic layer and/or antiferromagnetic (AFM) layer;
• the oblique ion beam sputtering being at angles α and β wherein each angle α and β is acute and wherein the angles α and β form first and second planes respectively which are orthogonal with respect to each other;
• and
• the angle β being 20° and the angle α being 40°.

A method of making a magnetic layer and/or an antiferromagnetic (AFM) layer for an electrical device comprising the steps of:

• obliquely ion beam sputtering at least one material layer from a target onto a substrate to form said magnetic layer and/or antiferromagnetic (AFM) layer;
• the oblique ion beam sputtering being at angles α and β wherein each angle α and β is acute and wherein the angles α and β form first and second planes respectively which are orthogonal with respect to each other;
• and
• the angle β being 30° and the angle α being 40°.

A method of making a magnetic layer and/or an antiferromagnetic (AFM) layer for an electrical device comprising the steps of:

• obliquely ion beam sputtering at least one material layer from a target onto a substrate to form said magnetic layer and/or antiferromagnetic (AFM) layer;
• the oblique ion beam sputtering being at angles α and β wherein each angle α and β is acute and wherein the angles α and β form first and second planes respectively which are orthogonal with respect to each other;
• said at least one material layer being a nickel iron film and first and second cobalt based films with the nickel iron layer being located between the first and second cobalt based films for forming said magnetic layer;
• and
• a second material layer comprising a nickel oxide film and an α phase iron oxide film that interface one another being obliquely ion beam sputtered at said angles α and β for forming said antiferromagnetic layer.

A method of making a magnetic layer and/or an antiferromagnetic (AFM) layer for an electrical device comprising the steps of:

• obliquely ion beam sputtering at least one material layer from a target onto a substrate to form said magnetic layer and/or antiferromagnetic (AFM) layer;
• the oblique ion beam sputtering being at angles α and β wherein each angle α and β is acute and wherein the angles α and β form first and second planes respectively which are orthogonal with respect to each other;
• said at least one material layer being a ferromagnetic free layer;
• forming a ferromagnetic pinned layer;
• forming a nonmagnetic spacer layer between the free and pinned layers;
• and
• the pinned and spacer layers being ion beam sputtered at an angle α which is acute and at an angle β which is 10° to 30°.

A method of ion beam sputtering at least one layer comprising the steps of:

• providing a substrate with a first planar surface;
• providing at least one target with a second planar surface wherein the target is composed of a desired material for said layer;
• positioning the planar surfaces at angles α and β with respect to one another wherein angle α forms a first plane intersecting the first and second planar surfaces and angle β forms a second plane intersecting the first and second planar surfaces as well as the first plane with the intersection of the first and second planes being orthogonal with respect to each other;
• and
• ion beam sputtering the target so that said material is sputtered from the target onto said substrate to form said layer.

A method of ion beam sputtering at least one layer comprising the steps of:

• providing a substrate with first planar surface;
• providing at least one target with a second planar surface wherein the target is composed of a desired material for said layer;
• positioning the planar surfaces at angles α and β with respect to one another wherein angle α forms a first plane intersecting the first and second planar surfaces and angle β forms a second plane intersecting the first and second planar surfaces as well as the first plane with the intersection of the first and second planes being orthogonal with respect to each other;
• and
• ion beam sputtering the target so that said material is sputtered from the target onto said substrate to form said layer;
• a central ion beam lying within said first plane;
• and
• the angle β being 10° to 30°.

A method of ion beam sputtering at least one layer comprising the steps of:

• providing a substrate with a first planar surface;
• providing at least one target with a second planar surface wherein the target is composed of a desired material for said layer;
• positioning the planar surfaces at angles α and β with respect to one another wherein angle α forms a first plane intersecting the first and second planar surfaces and angle β forms a second plane intersecting the first and second planar surfaces as well as the first plane with the intersection of the first and second planes being orthogonal with respect to each other;
• and
• ion beam sputtering the target so that said material is sputtered from the target onto said substrate to form said layer;
• a central ion beam lying within said first plane;
• and
• the angle β being 20° and the angle α being 40°.

A method of ion beam sputtering at least one layer comprising the steps of:

• providing a substrate with a first planar surface;
• providing at least one target with a second planar surface wherein the target is composed of a desired material for said layer;
• positioning the planar surfaces at angles α and β with respect to one another wherein angle α forms a first plane intersecting the first and second planar surfaces and angle β forms a second plane intersecting the first and second planar surfaces as well as the first plane with the intersection of the first and second planes being orthogonal with respect to each other;
• and
• ion beam sputtering the target so that said material is sputtered from the target onto said substrate to form said layer;
• a central ion beam lying within said first plane;
• and
• the angle β being 30° and the angle α being 40°.

A method of ion beam sputtering at least one layer comprising the steps of:

• providing a substrate with a first planar surface;
• providing at least one target with a second planar surface wherein the target is composed of a desired material for said layer;
• positioning the planar surfaces at angles α and β with respect to one another wherein angle α forms a first plane intersecting the first and second planar surfaces and angle β forms a second plane intersecting the first and second planar surfaces as well as the first plane with the intersection of the first and second planes being orthogonal with respect to each other;
• and
• ion beam sputtering the target so that said material is sputtered from the target onto said substrate to form said layer;
• a central ion beam lying within said first plane;
• said at least one layer being a nickel iron film and first and second cobalt based films with the nickel iron film being located between the first and second cobalt based films for forming said layer;
• and
• a second layer comprising a nickel oxide film and an α phase iron oxide film that interface one another being obliquely ion beam sputtered at said angles α and β for forming another layer.