Patent ID: 8049997
Filing Date: 2011-11-01
Classification: B82Y,G01R,G11B,H01F,H01L

Abstract:
1. A magnetoresistive element comprising: a first shield portion and a second shield portion; and an MR stack disposed between the first and second shield portions, wherein: the MR stack and the second shield portion are stacked in this order on the first shield portion; the first shield portion includes a first main shield layer, and a first exchange coupling shield layer disposed between the first main shield layer and the MR stack; the second shield portion includes a second main shield layer, and a second exchange coupling shield layer disposed between the second main shield layer and the MR stack; the first exchange coupling shield layer includes: an underlayer made of a nonmagnetic conductive material and disposed on the first main shield layer; a first antiferromagnetic layer disposed on the underlayer; and a first magnetization controlling layer disposed between the first antiferromagnetic layer and the MR stack; the second exchange coupling shield layer includes: a second antiferromagnetic layer; and a second magnetization controlling layer disposed between the second antiferromagnetic layer and the MR stack; the MR stack includes: a first free layer that is magnetically coupled to the first magnetization controlling layer and thereby has a magnetization in a controlled direction; a second free layer that is magnetically coupled to the second magnetization controlling layer and thereby has a magnetization in a controlled direction; and a spacer layer made of a nonmagnetic material and disposed between the first and second free layers; the first magnetization controlling layer includes a first ferromagnetic layer exchange-coupled to the first antiferromagnetic layer; the second magnetization controlling layer includes a second ferromagnetic layer exchange-coupled to the second antiferromagnetic layer; and only one of the first and second magnetization controlling layers further includes: a nonmagnetic middle layer made of a nonmagnetic conductive material and disposed between the first or second ferromagnetic layer and the MR stack: and a third ferromagnetic layer disposed between the nonmagnetic middle layer and the MR stack and antiferromagnetically exchange-coupled to the first or second ferromagnetic layer through the nonmagnetic middle layer.