公开(公告)号：DE69611326T2

公开(公告)日：2001-05-31

申请号：DE69611326

申请日：1996-06-13

Applicant: IBM

Inventor： FONTANA JR ,  GURNEY BRUCE ALVIN ,  LIN TSANN ,  SPERIOSU VIRGIL SIMON ,  TSANG CHING HWA ,  WILHOIT DENNIS RICHARD

IPC: G01R33/09 ,  G11B5/39 ,  H01F10/32 ,  H01L43/10

Abstract: A spin valve magnetoresistive (SVMR) sensor uses a laminated antiparallel (AP) pinned layer 70 in combination with an improved antiferromagnetic (AF) exchange biasing layer 57. The pinned layer comprises two ferromagnetic films 72, 74 separated by a nonmagnetic coupling film 73 such that the magnetizations of the two ferromagnetic films are strongly coupled together antiferromagnetically in an antiparallel orientation. This laminated AP pinned layer is magnetically rigid in the small field excitations required to rotate the SVMR sensor's free layer. When the magnetic moments of the two ferromagnetic layers in this AP pinned layer are nearly the same, the net magnetic moment of the pinned layer is small. However, the exchange field is correspondingly large because it is inversely proportional to the net magnetic moment. The laminated AP pinned layer has its magnetization fixed or pinned by an AF material that is highly corrosion resistant but that has an exchange anisotropy too low to be usable in conventional SVMR sensors. In the preferred embodiment the AF layer is nickel-oxide and is formed on one of the magnetoresistive (MR) shields that serves as the substrate 45. Thus the AF material also serves as the insulating MR gap material. The location of the AF layer and the laminated AP-pinned layer to which it is exchange coupled on the bottom of the SVMR sensor allows for improved longitudinal biasing of the free layer when the SVMR sensor is fabricated.

公开(公告)号：DE69611326D1

公开(公告)日：2001-02-01

申请号：DE69611326

申请日：1996-06-13

Applicant: IBM

Inventor： FONTANA JR ,  GURNEY BRUCE ALVIN ,  LIN TSANN ,  SPERIOSU VIRGIL SIMON ,  TSANG CHING HWA ,  WILHOIT DENNIS RICHARD

IPC: G01R33/09 ,  G11B5/39 ,  H01F10/32 ,  H01L43/10

Abstract: A spin valve magnetoresistive (SVMR) sensor uses a laminated antiparallel (AP) pinned layer 70 in combination with an improved antiferromagnetic (AF) exchange biasing layer 57. The pinned layer comprises two ferromagnetic films 72, 74 separated by a nonmagnetic coupling film 73 such that the magnetizations of the two ferromagnetic films are strongly coupled together antiferromagnetically in an antiparallel orientation. This laminated AP pinned layer is magnetically rigid in the small field excitations required to rotate the SVMR sensor's free layer. When the magnetic moments of the two ferromagnetic layers in this AP pinned layer are nearly the same, the net magnetic moment of the pinned layer is small. However, the exchange field is correspondingly large because it is inversely proportional to the net magnetic moment. The laminated AP pinned layer has its magnetization fixed or pinned by an AF material that is highly corrosion resistant but that has an exchange anisotropy too low to be usable in conventional SVMR sensors. In the preferred embodiment the AF layer is nickel-oxide and is formed on one of the magnetoresistive (MR) shields that serves as the substrate 45. Thus the AF material also serves as the insulating MR gap material. The location of the AF layer and the laminated AP-pinned layer to which it is exchange coupled on the bottom of the SVMR sensor allows for improved longitudinal biasing of the free layer when the SVMR sensor is fabricated.