Method for manufacturing magnetic laminated body and magnetic sensor, and apparatus for manufacturing magnetic laminated body

A method for manufacturing a magnetic sensor comprising steps of:

• arranging a ferromagnetic layer, a magnetically free layer whose magnetization direction changes with respect to an external magnetic field, a nonmagnetic layer, and an antiferromagnetic layer in the order of the magnetically free layer, the nonmagnetic layer, the ferromagnetic layer, and the antiferromagnetic layer in a first direction;
• forming a group of a first element unit and a second element unit in which said first element unit and said second element unit are connected in series, wherein each of said first and second element units comprises laminated film in which said ferromagnetic layer and said antiferromagnetic layer are in contact with each other, and in which one end of the group is connected to a power supply and other end is grounded;
• providing an output section between the first element unit and the second element unit;
• forming, from the ferromagnetic layer of the first element unit, a magnetically pinned layer, which has a pinned magnetization direction with respect to an external magnetic field, by applying a first magnetic field in the first direction to the first element unit;
• after stopping application of the first magnetic field, heating the first element unit to a temperature equal to or higher than a blocking temperature of the antiferromagnetic layer of the first element unit;
• forming, from the ferromagnetic layer of the second element unit, a magnetically pinned layer, which has a pinned magnetization direction with respect to an external magnetic field, by applying a second magnetic field including a component in a direction opposite to the first direction to the second element unit;
• and
• after stopping application of the second magnetic field, heating the second element unit to a temperature equal to or higher than a blocking temperature of the antiferromagnetic layer of the second element unit.

A method for manufacturing a magnetic sensor comprising steps of:

• arranging a ferromagnetic layer, a magnetically free layer whose magnetization direction changes with respect to an external magnetic field, a nonmagnetic layer, and an antiferromagnetic layer in the order of the magnetically free layer, the nonmagnetic layer, the ferromagnetic layer, and the antiferromagnetic layer in a first direction;
• forming a first group of a first element unit and a second element unit in which said first element unit and said second element unit are connected in series, and forming a second group of a third element unit and a fourth element unit in which said third element unit and said fourth element unit are connected in series, wherein each of the first to fourth element units comprises laminated film in which the ferromagnetic layer and the antiferromagnetic layer are in contact with each other and one end of each of the first and second groups is connected to a power supply and the other ends are grounded, and wherein the first element unit and the fourth element unit are arranged on the power-supply side, and the second element unit and the third element unit are arranged on the ground side;
• providing a differentiator for determining a difference between an output that is between the first element unit and the second element unit and an output that is between the third element unit and the fourth element unit;
• forming, from the ferromagnetic layers of the first and third element units, magnetically pinned layers, each of which having a pinned magnetization direction with respect to an external magnetic field, by applying a first magnetic field in the first direction to the first and third element units;
• after stopping application of the first magnetic field, heating the first and third element units to a temperature equal to or higher than blocking temperatures of the antiferromagnetic layers of the first and third element units;
• forming, from the ferromagnetic layers of the second and fourth element units, magnetically pinned layers, each of which having a pinned magnetization direction with respect to an external magnetic field, by applying a second magnetic field including a component in a direction opposite to the first direction to the second and fourth element units;
• and
• after stopping application of the second magnetic field, heating the second and fourth element units to a temperature equal to or higher than blocking temperatures of the antiferromagnetic layers of the second and fourth element units.

An apparatus for manufacturing a magnetic laminated body comprising:

• a magnetic field application device that applies a magnetic field in a first direction to a laminated film of a wafer that comprises the laminated film, in which a ferromagnetic layer and an antiferromagnetic layer are in contact with each other in the first direction, to form a magnetically pinned layer from the ferromagnetic layer, wherein a magnetization direction of the magnetically pinned layer is pinned with respect to an external magnetic field;
• a heating device that heats the laminated film to a temperature equal to or higher than a blocking temperature of the antiferromagnetic layer;
• and
• a transfer device that transfers the wafer between the magnetic field application device and the heating device.