Rotating magnetic field hall measurement system

Patent metadata

Field	Value
Publication number	US-9772385-B2
Application number	US-201514748495-A
Country	US
Kind code	B2
Filing date	Jun 24, 2015
Priority date	Apr 9, 2015
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A rotating magnetic field Hall apparatus is provided and includes first and second magnets disposed in a master-slave configuration, a device-under-test (DUT) stage interposable between the first and second magnets on which a DUT is disposable in first or second orientations for Hall measurement or photoelectromagnetic (PEM) testing, respectively, controllers disposed to center the DUT stage between the first and second magnets and orthogonal magnetic field sensors disposed aside lateral sides of the first magnet to facilitate positional initialization of the first and second magnets and to generate in-phase and out-of-phase reference signals for phase-sensitive or lock-in Hall signal detection. The system also includes software system to perform signal processing to yield the final Hall signal.

First claim

What is claimed is:

1. A method of operating a rotating magnetic field Hall apparatus, the method comprising:
dispsosing first and second magnets in a master-slave configuration;
interposing a device-under-test (DUT) stage between the first and second magnets;
disposing a DUT on the DUT stage in first or second orientations for Hall measurement or photoelectromagnetic (PEM) testing, respectively;
maneuvering the first magnet in a vertical dimension and maneuvering the second magnet in the vertical dimension and in a horizontal dimension to center the DUT stage between the first and second magnets;
disposing a first sensor on a first spire to face upwardly in the vertical dimension to face a lower facing lateral and non-longitudinal side of the first magnet;
disposing a second sensor on a second spire to face sideways in the horizontal dimension to face a sideways facing lateral and non-longitudinal side of the first magnet;
facilitating positional initialization of the first and second magnets; and
generating in-phase and out-of-phase reference signals for phase-sensitive or lock-in Hall signal detection.

2. The method according to claim 1 , further comprising disposing the first and second magnets in parallel.

3. The method according to claim 1 , further comprising increasing a magnetic field of one of the first and second magnets.

4. The method according to claim 3 , further comprising:
interposing a first magnetic flux concentrator between the first magnet and the DUT stage along the vertical dimension; and
interposing a second magnetic flux concentrator between the second magnet and the DUT stage along the vertical dimension.

5. The method according to claim 1 , further emitting light toward the DUT and applying current to the DUT.

6. A method of operating a computing system comprising a processor and a memory on which a program is stored, which, when executed causes the processor to manage a rotating magnet Hall apparatus, comprising:
first and second magnets disposed in a master-slave configuration; and
a device-under-test (DUT) stage interposable between the first and second magnets on which a DUT is disposable in first or second orientations for Hall measurement or photoelectromagnetic (PEM) testing, respectively, the method comprising:
maneuvering the first magnet in a vertical dimension and maneuvering the second magnet in the vertical dimension and in a horizontal dimension to center the DUT stage between the first and second magnets; and
operating orthogonal magnetic field sensor assembly, comprising:
first and second transversely oriented spires;
a first sensor disposed on the first spire to face upwardly in the vertical dimension to face a lower facing lateral and non-longitudinal side of the first magnet; and
a second sensor disposed on the second spire to face sideways in the horizontal dimension to face a sideways facing lateral and non-longitudinal side of the first magnet,
the first and second sensors being configured to facilitate positional initialization of the first and second magnets and to generate in-phase and out-of-phase reference signals for phase-sensitive or lock-in Hall signal detection.

7. The method according to claim 6 , wherein the processor is configured to perform signal processing to extract a final Hall signal and comprises:
a signal conditioning system for data selection and background subtraction;
a power spectral density analysis system; and
a system for lock-in detection and signal-to-noise ratio calculation.

Assignees

• IBM

Inventors

• Gunawan Oki
• Pereira Michael A

Classifications

• G01R33/072 Primary

  Constructional adaptation of the sensor to specific applications · CPC title

• G01R33/07 Primary

  Hall effect devices · CPC title

• G01N27/72

  by investigating magnetic variables · CPC title