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CN-122000188-A - Method for manufacturing magnetic laminate and magnetic sensor, and apparatus for manufacturing magnetic laminate

CN122000188ACN 122000188 ACN122000188 ACN 122000188ACN-122000188-A

Abstract

In a method for manufacturing a magnetic laminate, a laminated film (601) having a ferromagnetic layer (631) and an antiferromagnetic layer (66) and the ferromagnetic layer (631) and the antiferromagnetic layer (66) being in contact with each other in a first direction Z is formed (step S1). Then, a magnetic field in a first direction Z is applied to the laminated film (601), and a magnetization fixed layer (63) having a magnetization direction fixed to an external magnetic field is formed from the ferromagnetic layer (631) (step S2). After stopping the application of the magnetic field, the laminated film (601) is heated at a temperature equal to or higher than the blocking temperature of the antiferromagnetic layer (66), and a magnetic laminate (6) is produced (step S3).

Inventors

  • Ohmura Hiroaki

Assignees

  • TDK株式会社

Dates

Publication Date
20260508
Application Date
20251031
Priority Date
20241101

Claims (14)

  1. 1. A method of manufacturing a magnetic layer stack, comprising the steps of: Forming a laminated film having a ferromagnetic layer and an antiferromagnetic layer, the ferromagnetic layer and the antiferromagnetic layer being in contact with each other in a first direction; applying a magnetic field in the first direction to the laminated film, forming a magnetization fixed layer having a magnetization direction fixed to an external magnetic field from the ferromagnetic layer, and After stopping the application of the magnetic field, the laminated film is heated at a temperature equal to or higher than the blocking temperature of the antiferromagnetic layer, thereby producing a magnetic laminate.
  2. 2. The manufacturing method according to claim 1, wherein, The laminated film is heated by laser light.
  3. 3. The manufacturing method according to claim 1, wherein, After stopping the application of the magnetic field, the laminated film is transferred for heating the laminated film.
  4. 4. The method according to any one of claim 1 to 3, wherein, The laminated film has a magnetization free layer whose magnetization direction changes with respect to an external magnetic field, and a nonmagnetic layer, The ferromagnetic layer, the antiferromagnetic layer, the magnetization free layer, and the nonmagnetic layer are arranged in the order of the magnetization free layer, the nonmagnetic layer, the ferromagnetic layer, and the antiferromagnetic layer along the first direction.
  5. 5. The method according to any one of claim 1 to 3, wherein, The laminated film has a magnetization free layer whose magnetization direction changes with respect to an external magnetic field, a nonmagnetic layer, an intermediate ferromagnetic layer, and an intermediate layer made of a nonmagnetic metal, The ferromagnetic layer, the antiferromagnetic layer, the magnetization free layer, the nonmagnetic layer, the intermediate ferromagnetic layer, and the intermediate layer are arranged in the order of the magnetization free layer, the nonmagnetic layer, the intermediate ferromagnetic layer, the intermediate layer, the ferromagnetic layer, and the antiferromagnetic layer in the first direction.
  6. 6. The manufacturing method according to claim 5, wherein, When the magnetic moment of the intermediate ferromagnetic layer is M1 and the magnetic moment of the ferromagnetic layer is M2, |M2-M1|/M1 is 3% to 20%.
  7. 7. The manufacturing method according to claim 5, wherein, The magnitudes of perpendicular magnetic anisotropies of the intermediate ferromagnetic layer and the ferromagnetic layer are different from each other.
  8. 8. The manufacturing method according to claim 5, wherein, In the absence of the external magnetic field, the magnetization direction of the magnetization free layer forms a vortex shape on a plane orthogonal to the first direction.
  9. 9. The manufacturing method according to claim 5, wherein, The nonmagnetic layer is composed of an insulating layer.
  10. 10. A method for manufacturing a magnetic sensor includes the steps of: Providing a first element unit and a second element unit in such a manner that the first element unit and the second element unit form a group connected in series, and one end of the group is connected to a power source and the other end is grounded, wherein the first element unit and the second element unit each include a laminated film in which a ferromagnetic layer, a magnetization free layer whose magnetization direction changes with respect to an external magnetic field, a nonmagnetic layer, and an antiferromagnetic layer are arranged in the order of the magnetization free layer, the nonmagnetic layer, the ferromagnetic layer, and the antiferromagnetic layer in the first direction, and the ferromagnetic layer and the antiferromagnetic layer are connected to each other; An output section is provided between the first element unit and the second element unit; applying a first magnetic field in the first direction to the first element unit, and forming a magnetization fixed layer having a magnetization direction fixed with respect to an external magnetic field from the ferromagnetic layer of the first element unit; Heating the first element unit at a temperature equal to or higher than a blocking temperature of the antiferromagnetic layer of the first element unit after stopping the application of the first magnetic field; Applying a second magnetic field having a component in a direction opposite to the first direction to the second element unit, forming a magnetization fixed layer having a magnetization direction fixed with respect to an external magnetic field from the ferromagnetic layer of the second element unit, and After stopping the application of the second magnetic field, the second element unit is heated at a temperature that is above a blocking temperature of the antiferromagnetic layer of the second element unit.
  11. 11. A method for manufacturing a magnetic sensor includes the steps of: Providing first to fourth element units as a first group in which the first element unit and the second element unit are connected in series, the third element unit and the fourth element unit are connected in series, one end of the first group and one end of the second group are connected to a power source and the other end of the second group is grounded, the first element unit and the fourth element unit are arranged on one side of the power source, and the second element unit and the third element unit are arranged on the ground side, wherein the first to fourth element units respectively include laminated films in which a ferromagnetic layer, a magnetization free layer whose magnetization direction is changed with respect to an external magnetic field, a nonmagnetic layer, and an antiferromagnetic layer are arranged in the order of the magnetization free layer, the nonmagnetic layer, the ferromagnetic layer, and the antiferromagnetic layer along the first direction, and the ferromagnetic layer and the antiferromagnetic layer are in contact with each other; manufacturing a differentiator, wherein the differentiator obtains a difference value between the output of the first element unit and the second element unit and the output of the third element unit and the fourth element unit; Applying a first magnetic field in the first direction to the first and third element units, and forming a magnetization fixed layer having a magnetization direction fixed with respect to an external magnetic field from the ferromagnetic layers of the first and third element units; After stopping the application of the first magnetic field, heating the first and third element units at a temperature equal to or higher than the blocking temperature of the antiferromagnetic layer of the first and third element units; Applying a second magnetic field having a component in a direction opposite to the first direction to the second and fourth element units, forming a magnetization fixed layer having a magnetization direction fixed with respect to an external magnetic field from the ferromagnetic layers of the second and fourth element units, and After stopping the application of the second magnetic field, the second and fourth element units are heated at a temperature that is above the blocking temperature of the antiferromagnetic layer of the second and fourth element units.
  12. 12. The manufacturing method according to claim 10 or 11, wherein, The second magnetic field has a direction opposite to the first direction.
  13. 13. An apparatus for manufacturing a magnetic layer stack, comprising: A magnetic field applying device that applies a magnetic field in a first direction to a laminated film of a wafer including the laminated film, and that produces a magnetization fixed layer having a magnetization direction fixed with respect to an external magnetic field from a ferromagnetic layer, wherein the ferromagnetic layer and an antiferromagnetic layer are in contact with each other in the first direction; A heating device for heating the laminated film at a temperature equal to or higher than the blocking temperature of the antiferromagnetic layer, and And a transfer device for transferring the wafer between the magnetic field applying device and the heating device.
  14. 14. The manufacturing apparatus as set forth in claim 13, wherein, The heating device has a laser irradiation device for heating the laminated film by laser light.

Description

Method for manufacturing magnetic laminate and magnetic sensor, and apparatus for manufacturing magnetic laminate Technical Field The present disclosure relates to a method of manufacturing a magnetic stack and a magnetic sensor, and an apparatus for manufacturing a magnetic stack. Background Japanese patent application laid-open No. 2018-6598 describes a magnetic sensor having a magnetization free layer whose magnetization direction changes with respect to an external magnetic field, a magnetization fixed layer whose magnetization direction is fixed with respect to the external magnetic field, and a nonmagnetic layer located between the magnetization free layer and the magnetization fixed layer. The magnetization direction of the magnetization fixed layer is inverted when subjected to a strong magnetic field, and the magnetization direction may be fixed in an inverted state. In order to avoid this, as described in Japanese patent application laid-open No. 2015-207625, it is known to provide an antiferromagnetic layer and strongly fix the magnetization direction of the magnetization fixed layer by exchange coupling between the antiferromagnetic layer and the magnetization fixed layer. Disclosure of Invention An object of the present disclosure is to provide a method of manufacturing a magnetic layer stack capable of simplifying a device for magnetization of a magnetization fixed layer and heating of an antiferromagnetic layer. A method for producing a magnetic laminate includes forming a laminate film having a ferromagnetic layer and an antiferromagnetic layer, the ferromagnetic layer and the antiferromagnetic layer being in contact with each other in a first direction, applying a magnetic field in the first direction to the laminate film, producing a magnetization fixed layer having a magnetization direction fixed to an external magnetic field from the ferromagnetic layer, and heating the laminate film at a temperature equal to or higher than a blocking temperature (blocking temperature) of the antiferromagnetic layer after stopping the application of the magnetic field. Drawings Fig. 1a to 1b are schematic configuration diagrams of a magnetic sensor according to a first embodiment. Fig. 2a to 2b are schematic diagrams showing a magnetization method of a magnetization fixed layer of the magnetic sensor shown in fig. 1a to 1b and a heating method of a laminated film. Fig. 3 is a schematic configuration diagram of a magnetic field application heating device of the magnetic sensor shown in fig. 1a to 1 b. Fig. 4a to 4b are schematic configuration diagrams of a magnetic sensor according to a second embodiment. Fig. 5 is a structural diagram of a laminated film in the second embodiment. Fig. 6 is a schematic configuration diagram of a magnetic sensor according to a third embodiment. Fig. 7 (a) - (D) are schematic diagrams showing a magnetization method of the magnetization pinned layer and a heating method of the laminated film of the magnetic sensor shown in fig. 6. Fig. 8 is a schematic configuration diagram of a magnetic sensor according to a fourth embodiment. Fig. 9 (a) - (D) are schematic diagrams showing a magnetization method of the magnetization pinned layer and a heating method of the laminated film of the magnetic sensor shown in fig. 8. Fig. 10a to 10b are graphs showing measurement results of magnetization curves in examples and comparative examples. Symbol description 1. Magnetic sensor 2. Magnetic field detecting element 6. Magnetic laminate 7. Lower electrode layer 11-14 First-fourth element units 61. Magnetization free layer 62. A first nonmagnetic layer 63. First magnetization fixed layer 64. Intermediate layer 65. Second magnetization fixed layer 66. Antiferromagnetic layer 100. Magnetizing and heating device 101. Magnetic field applying device 102. Heating device 103. Transfer device Detailed Description The magnetization pinned layer of the magnetic sensor needs to be magnetized, and the antiferromagnetic layer needs to be heated at a temperature equal to or higher than the blocking temperature for exchange coupling. In the magnetic sensor described in japanese patent application laid-open No. 2018-6598, the magnetization direction of the magnetization fixed layer is oriented in the lamination direction of the magnetization free layer, the nonmagnetic layer, and the magnetization fixed layer. Therefore, magnetization of the magnetization pinned layer and heating of the antiferromagnetic layer need to be performed from the same direction. However, since the magnetization and heating are performed in the same process, the apparatus for magnetization and heating becomes complicated. Some embodiments of the present disclosure are described below with reference to the accompanying drawings. In the following description and the accompanying drawings, the direction in which the plurality of layers of the magnetic stack 6 and the laminated film 601 are stacked (first direction) is referred to as th