Abstract: A sensor includes first and second magnetoresistive sensor elements configured to produce respective first and second output signals in response to an external magnetic field. The first and second magnetoresistive sensor elements form a gradient unit, each of the magnetoresistive sensor elements includes a sense layer having a vortex magnetization pattern. A processing circuit is coupled to the sensor elements and is configured to produce a differential output signal as a difference between the first and second output signals of the first and second magnetoresistive sensor elements of the gradient unit. The system includes an encoder that produces the external magnetic field and the sensor having one or more gradient units, in which the gradient units may be arranged in a second-order gradient sensing configuration.

Abstract: A magnetic field sensor includes a magnetic sense element and a shield structure formed on a substrate. The shield structure fully encircles the magnetic sense element for suppressing stray magnetic fields along a first axis and a second axis, both of which are parallel to a surface of the substrate and perpendicular to one another. A magnetic field is oriented along a third axis perpendicular to the surface of the substrate, and the magnetic sense element is configured to sense a magnetic field along the first axis. A magnetic field deflection element, formed on the substrate proximate the magnetic sense element, redirects the magnetic field from the third axis into the first axis to be sensed as a measurement magnetic field by the magnetic sense element. At least two magnetic field sensors, each fully encircled by a shield structure, form a gradient unit for determining a magnetic field gradient.

Abstract: A method includes performing an ion beam etching process on a tunnel magnetoresistance (TMR) stack to remove material portions of a first magnetic layer and a tunnel barrier layer of the TMR stack. The ion beam etching process stops at a top surface of a second magnetic layer of the TMR stack. A protective layer is deposited over the TMR stack. Another etch process is performed to remove the protective layer such that a portion of the second magnetic layer is exposed from the protective layer and a spacer is formed from a remaining portion of the protective layer. The spacer surrounds sidewalls of the first magnetic layer and the tunnel barrier layer. The portion of the second magnetic layer exposed from the protective layer is removed so that a TMR sensor element remains, where the TMR sensor element includes a bottom magnet, a top magnet, and a tunnel junction.

Abstract: A method includes performing an ion beam etching process on a tunnel magnetoresistance (TMR) stack to remove material portions of a first magnetic layer and a tunnel barrier layer of the TMR stack. The ion beam etching process stops at a top surface of a second magnetic layer of the TMR stack. A protective layer is deposited over the TMR stack. Another etch process is performed to remove the protective layer such that a portion of the second magnetic layer is exposed from the protective layer and a spacer is formed from a remaining portion of the protective layer. The spacer surrounds sidewalls of the first magnetic layer and the tunnel barrier layer. The portion of the second magnetic layer exposed from the protective layer is removed so that a TMR sensor element remains, where the TMR sensor element includes a bottom magnet, a top magnet, and a tunnel junction.

Abstract: A magnetic field sensor includes a magnetic sense element and a shield structure formed on a substrate. The shield structure fully encircles the magnetic sense element for suppressing stray magnetic fields along a first axis and a second axis, both of which are parallel to a surface of the substrate and perpendicular to one another. A magnetic field is oriented along a third axis perpendicular to the surface of the substrate, and the magnetic sense element is configured to sense a magnetic field along the first axis. A magnetic field deflection element, formed on the substrate proximate the magnetic sense element, redirects the magnetic field from the third axis into the first axis to be sensed as a measurement magnetic field by the magnetic sense element. At least two magnetic field sensors, each fully encircled by a shield structure, form a gradient unit for determining a magnetic field gradient.

Abstract: A method includes performing an ion beam etching process on a tunnel magnetoresistance (TMR) stack to remove material portions of a first magnetic layer and a tunnel barrier layer of the TMR stack. The ion beam etching process stops at a top surface of a second magnetic layer of the TMR stack. A protective layer is deposited over the TMR stack. Another etch process is performed to remove the protective layer such that a portion of the second magnetic layer is exposed from the protective layer and a spacer is formed from a remaining portion of the protective layer. The spacer surrounds sidewalls of the first magnetic layer and the tunnel barrier layer. The portion of the second magnetic layer exposed from the protective layer is removed so that a TMR sensor element remains, where the TMR sensor element includes a bottom magnet, a top magnet, and a tunnel junction.

Abstract: An apparatus for the qualitative and/or quantitative measurement of analytes, in particular in biological samples by means of receptor ligand binding and having a magnetizing device for the production of a magnetic field at the location of the sample and with a detection device for measurement of magnetic properties of the sample is characterized in that the magnetizing device is spatially disposed with respect to the detection device in such a fashion that the magnetic field produced by the magnetization device at the location of the magnetization is attenuated by at least a factor of 10, and preferentially by a factor of 1000 or more, at the location occupied by the sample during the measurement, or in that a switching device is provided for which, throughout a predetermined time duration and in particular during the measurement phase of the detection device can switch-off the magnetic field of the magnetizing device at the location of the sample.