Wafer alignment markers, systems, and related methods

1. A method, comprising:

applying a magnetic field to a wafer;

detecting residual magnetic fields from one or more alignment markers within the wafer;

responsive to the detected residual magnetic fields, determining locations of the one or more alignment markers;

based at least partially on the determined locations of the one or more alignment markers, determining a geometrical transformation model for aligning the wafer according to an ideal grid; and

aligning the wafer based on the geometrical transformation model.

2. The method of claim 1 , further comprising, before applying the magnetic field:

forming a pattern of recesses in a surface of the wafer; and

filling the pattern with a ferromagnetic or antiferromagnetic material or any other material or structure capable of interacting with a magnetic field to form the one or more alignment markers.

3. The method of claim 2 , wherein forming the pattern of recesses in the surface of the wafer comprises forming the pattern such that resulting alignment markers have longitudinal ends aligned along one of an X-axis, a Y-axis, or a Z-axis of a Cartesian space.

4. The method of claim 1 , wherein applying a magnetic field to the wafer comprises applying the magnetic field with an electromagnet.

5. The method of claim 1 , wherein detecting the residual magnetic fields from the one or more alignment markers within the wafer comprises detecting the one or more residual magnetic fields with a sensor selected from the group consisting of a Hall Effect sensor, a GMR sensor, a TMR sensor, an EMR sensor, or a spin hall sensor.

6. The method of claim 1 , wherein applying a magnetic field to the wafer comprises applying an in-plane magnetic field to the wafer.

7. The method of claim 1 , wherein applying a magnetic field to the wafer comprises applying an out of plane magnetic field to the wafer.

8. The method of claim 1 , wherein applying a magnetic field to the wafer comprises rotating all domains within the one or more alignment markers to be in known directions.

9. A method, comprising:

driving a magnetization of at least one alignment marker within a wafer;

measuring the magnetization of the at least one alignment marker;

responsive to the magnetization of the at least one alignment marker, determining a location of the at least one alignment marker relative to an ideal grid;

based at least partially on the determined location of the at least one alignment marker, determining a geometrical transformation model for aligning the wafer according to an ideal grid; and

aligning the wafer based on the geometrical transformation model.

10. The method of claim 9 , wherein measuring the magnetization of the at least one alignment marker within the wafer comprises measuring the magnetization with a sensor selected from the group consisting of a MFM probe, a SQUID, or VSM.

11. The method of claim 9 , wherein measuring the magnetization of the at least one alignment marker comprises measuring a magnetic force between the at least one alignment marker and a sensor.

12. The method of claim 9 , wherein driving magnetization of at least one alignment marker within a wafer comprises applying an external magnetic field to the wafer.

13. The method of claim 9 , further comprising, after alignment of the wafer:

subjecting the wafer to at least one semiconductor fabrication process; and

demagnetizing the at least one alignment marker.

14. The method of claim 9 , wherein measuring the magnetization of the at least one alignment marker comprises:

passing a sensor over a surface of the wafer;

detecting interactions between a magnetized tip of the sensor and the at least one alignment marker; and

responsive to the detected interactions, determining the magnetization of the at least one alignment marker.

15. A method, comprising:

applying a magnetic field to a wafer having one or more alignment markers comprising a ferromagnetic or antiferromagnetic material or any other material or structure capable of interacting with a magnetic field;

detecting one or more magnetic attributes of the one or more alignment markers with a sensor;

responsive to the detected one or more magnetic attributes of the one or more alignment markers, determining locations of the one or more alignment markers; and

based at least partially on the determined locations of the one or more alignment markers, determining a geometrical transformation model for aligning the wafer according to an ideal grid.

16. The method of claim 15 , wherein detecting one or more magnetic attributes comprises detecting a residual magnetic field of the one or more alignment markers.

17. The method of claim 15 , wherein detecting one or more magnetic attributes comprises measuring a magnetization of the one or more alignment markers.

18. The method of claim 15 , wherein detecting one or more magnetic attributes comprises approximating a residual magnetic field of the one or more alignment markers as a dipole.

19. The method of claim 15 , wherein detecting one or more magnetic attributes comprises approximating a residual magnetic field of the one or more alignment markers as a surface magnetic moment.

20. The method of claim 15 , further comprising:

determining locations of the one or more alignment markers relative to the ideal grid; and

aligning the wafer responsive to the geometrical transformation model.

21. A method, comprising:

applying a magnetic field to a wafer;

detecting a response from one or more alignment markers within the wafer;

responsive to the detected response from the one or more alignment markers, determining locations of the one or more alignment markers;

based at least partially on the determined locations of the one or more alignment markers, determining a geometrical transformation model for aligning the wafer according to an ideal grid; and

aligning the wafer based on the geometrical transformation model.

22. The method of claim 21 , wherein detecting a response from the one or more alignment markers within the wafer comprises detecting photon emissions from the one or more alignment markers.

23. The method of claim 21 , wherein detecting a response from the one or more alignment markers with in the wafer comprises detecting a DC magnetic field from the one or more alignment markers.

24. The method of claim 21 , further comprising disposing the one or more alignment markers comprising one or more circuits within recesses of a pattern within the wafer.