公开(公告)号：JPH11353621A

公开(公告)日：1999-12-24

申请号：JP14418599

申请日：1999-05-25

Applicant: IBM

Inventor： FONTANA JR ROBERT E ,  PARKIN STUART STEPHEN PAPWORTH ,  CHIN FA TSUAN

IPC: G01R33/06 ,  G11B5/39

Abstract: PROBLEM TO BE SOLVED: To prevent the shunting of the sense current to a bias ferromagnetic layer and to optimize a device by determining electric resistance to current flowing perpendicularly in respective layers in a stack by the relative directions of the magnetic moments of a stationary ferromagnetic layer and detecting ferromagnetic layer when electric leads are connected to a sensing circuit. SOLUTION: The bias magnetic field in the transverse direction to a magnetic tunnel junction device (MTJ) is obtd. by the ferromagnetic bias layer 320 having a longitudinally bias region 322 near the right and left edges 180 of a detecting layer and a transverse bias region 324 along a rear surface edge 190 apart from an air bearing surface (ABS) surface. The front edge of an MTJ sensor 100 is directly arranged on the ABS or is retreated from the ABS to introduce magnetic fluxes to the retreated front edge of the sensor by using a magnetic flux guide. The transverse bias magnetic field of an adequate quantity is made possible by using an additional bias region 324 at the rear surface edge 190.

公开(公告)号：JPH11213351A

公开(公告)日：1999-08-06

申请号：JP28902098

申请日：1998-10-12

Applicant: IBM

Inventor： DILL FREDERICK HAYES ,  FONTANA JR ROBERT E ,  PARKIN STUART STEPHEN PAPWORTH ,  TSANG CHING HWA

IPC: G11B5/39 ,  G11B5/33 ,  H01F10/16 ,  H01F10/32 ,  H01L43/08

Abstract: PROBLEM TO BE SOLVED: To reduce the gap between magnetic shields to obtain a high surface density. SOLUTION: The magnetic shield enables a head to detect each magnetic transition from a magnetic recording medium without interference of adjacent transitions and functions as an electric lead which connects the head to a detection circuit. Conductive spacer layer 102 and 104 are arranged above and below an MTJ(magnetic tunnel junction) element to connect the MTJ element to the shield. The thickness of spacer layere 102 and 104 are selected so as to optimize the gap between shields. This thickness is a parameter which controls the linear resolution of data read from the magnetic recording medium. If the gap between shields is narrow, each shield has a pedestal area for the purpose of reducing a possibility of electric short-circuit between shields, and the MTJ element can be arranged between these two pedestals. In this case, the gap between shields on the outside of pedestals is larger than the inside of pedestal areas.

公开(公告)号：JPH11213350A

公开(公告)日：1999-08-06

申请号：JP28901398

申请日：1998-10-12

Applicant: IBM

Inventor： FONTANA JR ROBERT E ,  PARKIN STUART STEPHEN PAPWORTH ,  TSANG CHING HWA ,  WILLIAMS MASON LAMAR

IPC: G11B5/39 ,  G11B5/33

Abstract: PROBLEM TO BE SOLVED: To provide a magnetic tunnel junction magneto-resistance reading head for magnetic recording system which gives a large output signal. SOLUTION: The magneto-resistance read head is provided with an MTJ detection or free ferromagnetic layer 132 functioning as a magnetic flux guide which directs a magnetic flux from a magnetic recording medium to a tunnel junction 100, and an MTJ fixed ferromagnetic layer 118 and an MTJ tunnel barrier layer 120 are provided with front edge parts 206 and 210 which are approximately level with the detection surface of the head, and the fixed ferromagnetic layer 118 and the free ferromagnetic layer 132 are brought into contact with opposite faced of the MTJ tunnel barrier layer 120, and the free ferromagnetic layer 132 is extended beyond the rear edge part of one of the free ferromagnetic layer 132 and the tunnel barrier layer 118 which has the rear edge part 208 or 212 nearer to the detection surface, and it is secured that the magnetic flux is non-zero in the tunnel junction area. The direction of magnetization of the fixed ferromagnetic layer 118 is fixed in the direction perpendicular to the detection surface by surface exchange coupling with an antiferromagnetic layer 116. The direction of magnetization of the free ferromagnetic layer 132 is made parallel with the surface of a medium when an applied magnetic field is zero, and it is freely rotated when an applied magnetic field exists.

公开(公告)号：JP2003077108A

公开(公告)日：2003-03-14

申请号：JP2002150087

申请日：2002-05-24

Applicant: Internatl Business Mach Corp ,  インターナショナル・ビジネス・マシーンズ・コーポレーション

Inventor： HARDAYAL SIN GILL ,  FONTANA JR ROBERT E

IPC: G11B5/39 ,  H01F10/16 ,  H01F10/30 ,  H01L43/08 ,  H01L43/12

CPC classification number: B82Y25/00 ,  B82Y10/00 ,  G11B5/3903 ,  G11B5/3909 ,  G11B5/3932 ,  G11B5/3967

Abstract: PROBLEM TO BE SOLVED: To provide a reading head having a tunnel junction sensor and a non-shunting vertical bias layer.
SOLUTION: The first and second vertical bias layers of a tunnel junction sensor are electrically insulative, and a current conducted through the tunnel junction sensor is not shunted. The first and second vertical bias layers are made of gamma iron oxide (λFe
2 O
3 ).
COPYRIGHT: (C)2003,JPO

Abstract translation: 要解决的问题：提供一种具有隧道结传感器和非分流垂直偏置层的读取头。 解决方案：隧道结传感器的第一和第二垂直偏置层是电绝缘的，并且通过隧道结传感器传导的电流不被分流。 第一和第二垂直偏置层由γ氧化铁（λFe2 O 3）制成。

公开(公告)号：JPH11213349A

公开(公告)日：1999-08-06

申请号：JP28899998

申请日：1998-10-12

Applicant: IBM

Inventor： FONTANA JR ROBERT E ,  PARKIN STUART STEPHEN PAPWORTH ,  TSANG CHING HWA

IPC: G11B5/39 ,  G11B5/40

Abstract: PROBLEM TO BE SOLVED: To provide an MTJ(magnetic tunnel junction) MR(magneto-resistance) read head free from problems accompanying the existence of an edge part of an exposed MTJ layer on a detection surface. SOLUTION: The MTJ magneto-resistance read head for magnetic recording system is provided with an MTJ detection or free ferromagnetic layer 132 functioning as a magnetic flux guide which directs a magnetic flux from a magnetic recording medium to a tunnel junction. An MTJ fixed ferromagnetic layer 118 has a front edge part retreated from the detection surface of the head. The fixed ferromagnetic layer and the free ferromagnetic layer are brought into contact with opposite faces of an MTJ tunnel barrier layer 120, but the free ferromagnetic layer is extended beyond the rear edge part of one of the tunnel barrier layer and the fixed ferromagnetic layer which has the rear edge part nearer to the detection surface. The direction of magnetization of the fixed ferromagnetic layer is desirably fixed in the direction of an arrow 119 approximately perpendicular to the detection surface, namely, the magnetic recording medium by surface exchange coupling with an antiferromagnetic layer.