Patent ID: 7965077

Claim:
A method for fabricating a ferromagnetic thin-film based magnetic field sensor comprising two or more reference layer directions, comprising: providing a substrate; forming a first insulating layer over the substrate; forming a sensor layer stack over the first insulating layer, the sensor layer stack comprising a reference layer structure formed over the first insulating layer, a nonmagnetic intermediate layer formed over the reference layer structure, and a sense layer formed over the nonmagnetic intermediate layer; selectively etching the sensor layer stack to form a first electrode stack and a second electrode stack, where the reference layer structure within the first electrode stack has a first shape anisotropy configured to set a first reference direction, and where the reference layer structure within the second electrode stack has a second shape anisotropy configured to set a second reference direction; applying a saturating field substantially parallel to the substrate that is oriented in a field direction between the first and second reference directions until each reference layer structure of the first and second electrode stacks has a magnetization that is substantially aligned with the field direction; and removing the saturating field to allow the first shape anisotropy to set the magnetization of the reference layer structure of the first electrode stack, and to allow the second shape anisotropy to set the magnetization of the reference layer structure of the second electrode stack.