Apparatus and method for fine-tuning magnet arrays with localized energy delivery

Patent metadata

Field	Value
Publication number	US-9779872-B2
Application number	US-201414565166-A
Country	US
Kind code	B2
Filing date	Dec 9, 2014
Priority date	Dec 23, 2013
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

One embodiment relates to an apparatus for adjustment of local magnetic strength in a magnetic device. A stage holds the magnetic device, and a sensor measures a magnetic field at locations above the magnetic device so as to generate magnetic field data. A computer system detects a non-uniformity in the magnetic field from the magnetic field data and determines a location and a duration for application of a pulsed laser beam to correct the non-uniformity. A laser device applies the pulsed laser beam at said location for said duration. Another embodiment relates to a method of adjusting local magnetic strength in a magnetic device. Another embodiment relates to a system for fine-tuning a magnet array with localized energy delivery. Other embodiments, aspects and features are also disclosed.

First claim

What is claimed is:

1. An apparatus for adjustment of local magnetic strength in a magnetic device, the apparatus comprising:
a stage for holding the magnetic device;
a sensor that measures a magnetic field at locations above the magnetic device so as to generate magnetic field data;
a computer system that detects a non-uniformity in the magnetic field from the magnetic field data, wherein the non-uniformity comprises a shift in a position of a peak in the magnetic field, and determines a location and a duration for application of a pulsed laser beam to correct the non-uniformity; and
a laser device that applies the pulsed laser beam at a section on one side of the peak for said duration to correct the position of the peak.

2. The apparatus of claim 1 , wherein the stage comprises a translatable stage that is controlled by the computer system.

3. The apparatus of claim 2 , wherein translatable stage controllably moves the magnetic device in three dimensions.

4. The apparatus of claim 1 , wherein the sensor comprises a Hall sensor that measures the magnetic field using the Hall effect.

5. The apparatus of claim 1 , wherein the sensor comprises a magnetoresistive sensor.

6. The apparatus of claim 1 , wherein the sensor comprises a giant magnetoresistive sensor.

7. The apparatus of claim 1 , wherein the sensor comprises a magneto optical Kerr effect sensor.

8. The apparatus of claim 1 , wherein non-uniformities in the magnetic field comprise deviations from an expected magnetic field.

9. The apparatus of claim 1 , wherein the laser device has a controllable orientation so as to controllably change an incident angle of the pulsed laser beam onto the magnetic device.

10. The apparatus of claim 1 , further comprising:
an inspection microscope for aligning the magnetic device for targeted application of the pulsed laser beam.

11. The apparatus of claim 10 , wherein the inspection microscope comprises an optical microscope.

12. The apparatus of claim 1 , wherein the magnetic device comprises a magnetic lens, and wherein the non-uniformity causes astigmatism of the magnetic lens.

13. A method of adjusting local magnetic strength in a magnetic device, the method comprising:
holding the magnetic device using a translatable stage;
measuring a magnetic field using a sensor at locations above the magnetic device so as to generate magnetic field data;
detecting a deviation in the magnetic field from the magnetic field data, wherein the deviation comprises a shift in a position of a peak in the magnetic field;
determining a location and a duration for application of a pulsed laser beam to correct the deviation; and
applying the pulsed laser beam at a section on one side of the peak for said duration for adjustment of the local magnetic strength to correct the position of the peak.

14. The method of claim 13 , further comprising:
measuring the magnetic field using the sensor after said applying to check a result of said adjustment of the local magnetic strength.

15. The method of claim 14 , further comprising:
detecting a remaining deviation in the magnetic field from said check;
determining a second location and a second duration for application of the pulsed laser beam to correct the remaining deviation; and
applying the pulsed laser beam at said second location for said second duration for further adjustment of the local magnetic strength.

16. A system for fine-tuning a magnet array with localized energy delivery, the system comprising:
a translatable stage for holding and translating the magnet array;
an inspection microscope for aligning a position of the magnet array;
a sensor that measures a magnetic field at locations above the magnet array so as to generate magnetic field data;
a computer apparatus that detects a deviation in the magnetic field from the magnetic field data, wherein the deviation comprises a shift in a position of a peak in the magnetic field; and
a laser device that applies the pulsed laser beam a section on one side of the peak to correct the position of the peak.

17. The system of claim 16 , wherein the magnet array comprises an array of magnetic lenses.

18. The system of claim 17 , wherein the deviation causes astigmatism or variation in peak strength in focusing of a magnetic lens of the array.

19. The system of claim 16 , wherein the system is automated under control of the computer apparatus so as to fine-tune the magnetic field generated by the magnet array.

20. The system of claim 19 , wherein a control module of the computer apparatus is configured to perform steps comprising:
using the sensor and translation of the stage to measure the magnetic field at multiple locations above the magnet array so as to generate the magnetic field data;
detecting the deviation in the magnetic field from the magnetic field data;
determining a location and a duration for application of the pulsed laser beam to mitigate the deviation; and
applying the pulsed laser beam at said location for said duration.

Assignees

• Kla Tencor Corp

Inventors

• Gerling John

Classifications

• H01F41/0286 Primary

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