公开(公告)号：US20240103100A1

公开(公告)日：2024-03-28

申请号：US17935013

申请日：2022-09-23

Applicant: Apple Inc.

Inventor： Jason Janesky ,  Savas Gider

IPC: G01R33/09

CPC classification number: G01R33/093 ,  G01R33/091

Abstract: Embodiments are disclosed for yoke structures for improved magnetometer performance. In an embodiment, a magnetometer comprises: a yoke structure comprising at least one hard magnetic layer and at least one soft magnetic layer arranged along a dimension of the yoke structure, where a first coercivity of the at least one hard magnetic layer is greater than a second coercivity of the at least one soft magnetic layer; and at least one magnetic sensing element located in proximity to the at least one soft magnetic layer. In another embodiment, a magnetometer comprises: a multilayer yoke structure comprising layers of non-magnetic material and magnetic material along a dimension of the yoke structure; and at least one magnetic sensing element located in proximity to the yoke structure.

公开(公告)号：US20240107892A1

公开(公告)日：2024-03-28

申请号：US17934969

申请日：2022-09-23

Applicant: Apple Inc.

Inventor： Jason Janesky ,  Jodi M. Iwata-Harms ,  Savas Gider

IPC: H01L43/08 ,  G01R33/09 ,  G11C11/16 ,  H01F10/32 ,  H01L43/10

CPC classification number: H01L43/08 ,  G01R33/093 ,  G11C11/161 ,  H01F10/3272 ,  H01L43/10

Abstract: The enclosed embodiments are directed to a magnetoresistance (MR) sensor with a biased free layer for improved stability of magnetic performance. In an embodiment, an MR sensor comprises: a first antiferromagnetic (AF) pinning layer; a magnetic fixed layer disposed on the first AF layer; a tunnel barrier disposed on the magnetic fixed layer; a magnetic coupled free layer disposed on the tunnel barrier; a AF coupling layer disposed on the magnetic coupled free layer; a magnetic pinned layer disposed on the AF coupling layer; and a second AF pinning layer disposed on the magnetic pinned layer. In an embodiment, a method of unpinning a pinned free layer uses a current pulse through the MR sensor to self-heat above a blocking temperature of the AF pinning layer, and then reading the MR sensor after the current pulse is reduced or removed and the MR sensor cools back below the blocking temperature.