Method for forming a hard bias structure in a magnetoresistive sensor

A method for forming a hard bias structure in a magnetoresistive sensor, comprising

• providing a substrate comprising a clap layer having a top surface;
• forming a magnetoresistive sensor structure over the substrate, the magnetoresistive sensor structure comprising at least a soft magnetic bias layer, a spacer layer over the soft magnetic bias layer, and a magnetoresistive layer over the spacer layer;
• forming a mask over a portion of the magnetoresistive sensor structure to define a central region of the magnetoresistive sensor;
• ion milling the masked magnetoresistive structure to remove portions of the magnetoresistive sensor structure not shielded by the mask, to form a central region of the magnetoresistive sensor having sloped sides, and to expose a region of the clap layer laterally adjacent the sloped sides of the central region;
• forming a first underlayer onto at least the sloped sides of the central region by depositing a first underlayer material at a high deposition angle;
• forming a second underlayer at least partially overlapping the first underlayer by depositing a second underlayer material at a first lower deposition angle;
• and forming a hard bias layer over at least a portion of the second underlayer by depositing a hard bias material at a second lower deposition angle, wherein forming the first underlayer onto the sloped sides of the central region and onto the exposed substrate comprises depositing the underlayer material at a deposition angle at least about 20° from perpendicular to an upper surface of the substrate.

A method for forming a hard bias structure in a magnetoresistive sensor, comprising

• providing a substrate comprising a clap layer having a top surface;
• forming a magnetoresistive sensor structure over the substrate, the magnetoresistive sensor structure comprising at least a soft magnetic bias layer, a spacer layer over the soft magnetic bias layer, and a magnetoresistive layer over the spacer layer;
• forming a mask over a portion of the magnetoresistive sensor structure to define a central region of the magnetoresistive sensor;
• ion milling the masked magnetoresistive structure to remove portions of the magnetoresistive sensor structure not shielded by the mask, to form a central region of the magnetoresistive sensor having sloped sides, and to expose a region of the clap layer laterally adjacent the sloped sides of the central region;
• forming a first underlayer onto at least the sloped sides of the central region by depositing a first underlayer material at a high deposition angle;
• forming a second underlayer at least partially overlapping the first underlayer by depositing a second underlayer material at a first lower deposition angle;
• and forming a hard bias layer over at least a portion of the second underlayer by depositing a hard bias material at a second lower deposition angle, wherein forming the first underlayer onto the sloped sides of the central region and onto the exposed substrate comprises depositing the underlayer material at a deposition angle generally normal to the slope of the sides of the central region at the junction.

A method for forming a hard bias structure in a magnetoresistive sensor, comprising

• providing a substrate comprising a clap layer having a top surface;
• forming a magnetoresistive sensor structure over the substrate, the magnetoresistive sensor structure comprising at least a soft magnetic bias layer, a spacer layer over the soft magnetic bias layer, and a magnetoresistive layer over the spacer layer;
• forming a mask over a portion of the magnetoresistive sensor structure to define a central region of the magnetoresistive sensor;
• ion milling the masked magnetoresistive structure to remove portions of the magnetoresistive sensor structure not shielded by the mask, to form a central region of the magnetoresistive sensor having sloped sides and to expose a region of the clap layer laterally adjacent the sloped sides of the central region;
• forming a first underlayer onto at least the sloped sides of the central region by depositing a first underlayer material at a high deposition angle;
• forming a second underlayer at least partially overlapping the first underlayer by depositing a second underlayer material at a first lower deposition angle;
• and forming a hard bias layer over at least a portion of the second underlayer by depositing a hard bias material at a second lower deposition angle, wherein forming a second underlayer on a portion of the first underlayer comprises depositing the underlayer material at a deposition angle generally normal to an upper surface of the substrate.

A method for forming a hard bias structure in a magnetoresistive sensor, comprising

• providing a substrate comprising a clap layer having a top surface;
• forming a magnetoresistive sensor structure over the substrate, the magnetoresistive sensor structure comprising at least a soft magnetic bias layer, a spacer layer over the soft magnetic bias layer, and a magnetoresistive layer over the spacer layer;
• forming a mask over a portion of the magnetoresistive sensor structure to define a central region of the magnetoresistive sensor;
• ion milling the masked magnetoresistive structure to remove portions of the magnetoresistive sensor structure not shielded by the mask, to form a central region of the magnetoresistive sensor having sloped sides and to expose a region of the clap layer laterally adjacent the sloped sides of the central region;
• forming a first underlayer onto at least the sloped sides of the central region by depositing a first underlayer material at a high deposition angle;
• forming a second underlayer at least partially overlapping the first underlayer by depositing a second underlayer material at a first lower deposition angle;
• and forming a hard bias layer over at least a portion of the second underlayer by depositing a hard bias material at a second lower deposition angle, wherein ion milling to remove portions of the magnetoresistive sensor structure not shielded by the mask further comprises overmilling, to remove a portion of the gap layer.