Magnetic read sensor employing oblique etched underlayers for inducing uniaxial magnetic anisotropy in a self biased free layer

A magnetoresistive sensor, comprising:

• a magnetic free layer;
• a magnetic pinned layer structure;
• a non-magnetic spacer sandwiched between the free layer and the pinned layer structure;
• an underlayer formed adjacent to the free layer opposite the spacer layer, the underlayer having a surface having an anisotropic roughness, the surface being disposed adjacent to the free layer and inducing magnetic anisotropy in the free layer.

A magnetoresistive sensor, comprising:

• a magnetic free layer;
• a magnetic pinned layer structure;
• a non-magnetic spacer layer sandwiched between the free layer and the pinned layer structure;
• a magnetic bias layer;
• an orthogonal coupling layer sandwiched between the magnetic bias layer and the free layer;
• and
• an underlayer formed adjacent to the bias layer opposite the orthogonal coupling layer, the underlayer having a surface formed with an anisotropic roughness configured to induce a magnetic anisotropy in the bias layer.

A method for manufacturing a magnetoresistive sensor, comprising:

• depositing an underlayer having an upper surface;
• performing an ion etch at an oblique angle with respect to the surface of the underlayer and without rotating the substrate;
• and
• depositing a magnetic free layer.

A method for manufacturing a magnetoresistive sensor, comprising:

• depositing an underlayer having an upper surface;
• performing a first ion etch for some time at an oblique angle with respect to the surface of the underlayer and without rotating the substrate;
• rotating the substrate about 180 degrees in-plane;
• performing a second ion etch for about the same time and under the same oblique angle with respect to the surface of the underlayer as the first ion etch and without rotating the substrate;
• and
• depositing a magnetic free layer.

A method for manufacturing a magnetoresistive sensor, comprising:

• depositing a magnetic pinned layer structure;
• depositing a non-magnetic spacer layer over the pinned layer structure the spacer layer having a surface;
• performing an ion etch at an oblique angle with respect to the surface of the spacer layer;
• and
• depositing a free layer.

A method for manufacturing a magnetoresistive sensor, comprising:

• depositing a magnetic pinned layer structure;
• depositing a non-magnetic spacer layer over the pinned layer structure the spacer layer having a surface;
• performing a first ion etch at an oblique angle with respect to the surface of the spacer layer;
• rotating the substrate about 180 degrees in-plane;
• performing a second ion etch for about the same time and under the same oblique angle with respect to the surface of the underlayer as the first ion etch and without rotating the substrate;
• and
• depositing a free layer.