Fabrication process and layout for magnetic sensor arrays

摘要

A magnetic sensor includes a plurality of groups, each group comprising a plurality of magnetic tunnel junction (MTJ) devices having a plurality of conductors configured to couple the MTJ devices within one group in parallel and the groups in series enabling independent optimization of the material resistance area (RA) of the MTJ and setting total device resistance so that the total bridge resistance is not so high that Johnson noise becomes a signal limiting concern, and yet not so low that CMOS elements may diminish the read signal. Alternatively, the magnetic tunnel junction devices within each of at least two groups in series and the at least two groups in parallel resulting in the individual configuration of the electrical connection path and the magnetic reference direction of the reference layer, leading to independent optimization of both functions, and more freedom in device design and layout. The X and Y pitch of the sense elements are arranged such that the line segment that stabilizes, for example, the right side of one sense element; also stabilizes the left side of the adjacent sense element.

主权项

1. A magnetic sensor comprising at least one array, each array comprising:
a plurality of groups, each group comprising one or more subgroupings of magnetic tunnel junction devices, each subgrouping comprising:
a shaped reference element comprising:
an electrode; anda shaped reference layer over the electrode,a tunnel barrier layer over the shaped reference layer; anda plurality of sense elements over the tunnel barrier layer,wherein a sense element, the portion of the tunnel barrier layer under the sense element, and the portion of the shaped reference element under the sense element form a magnetic tunnel junction device; and a plurality of conductors over the plurality of magnetic tunnel junction devices, wherein the plurality of conductors and one or more of the electrodes are configured to electrically couple one of:
the magnetic tunnel junction devices within each group in parallel and the groups in series; orthe magnetic tunnel junction devices within each of the plurality of groups in series and the plurality of groups in parallel.