Methods of forming magnetic memory cells, and methods of forming arrays of magnetic memory cells

1. A method of forming a magnetic memory cell, the method comprising:

forming a magnetic cell core material over a base material, forming the magnetic cell core material comprising:

forming a first magnetic region over the base material;

forming a tunnel barrier material over the first magnetic region; and

forming a second magnetic region over the tunnel barrier material;

maintaining a temperature of at least one of the base material or a wafer stage underlying the base material at a temperature below about 0° C.;

exposing the magnetic cell core material to at least a first beam comprising one of an ion beam or a neutral beam comprising ions or elements of at least one noble gas to remove portions of the magnetic cell core material while the temperature of the at least one of the base material or the wafer stage is below about 0° C.; and

exposing the magnetic cell core material to a second beam comprising one of an ion beam or a neutral beam comprising at least one noble gas and at least one oxygen-containing gas.

2. The method of claim 1 , wherein exposing the magnetic cell core material to the at least a first beam comprises exposing the magnetic cell core material to the at least a first beam while maintaining the temperature of at least one of the base material or the wafer stage below about −50° C.

3. The method of claim 1 , wherein exposing the magnetic cell core material to at least a first beam comprises exposing the magnetic cell core to a first beam having an energy between about 200 eV and about 1,000 eV.

4. The method of claim 1 , further comprising selecting the at least one noble gas of the first beam to comprise at least one of neon, argon, or krypton.

5. The method of claim 1 , wherein:

exposing the magnetic cell core material to at least a first beam comprises forming a magnetic memory cell; and

exposing the magnetic cell core material to a second beam comprising one of an ion beam or a neutral beam comprising at least one noble gas and at least one oxygen-containing gas comprises forming an oxide material over sidewalls of the magnetic memory cell.

6. The method of claim 1 , further comprising selecting the at least one oxygen-containing gas to comprise at least one of oxygen, ozone, nitric oxide, nitrous oxide, nitrogen dioxide, carbon monoxide, or carbon dioxide.

7. The method of claim 1 , further comprising selecting the second beam to comprise between about 0.1 part and about 10 parts of the oxygen-containing gas for every about 1 part of the at least one noble gas.

8. The method of claim 1 , further comprising selecting a beam angle of the second beam to be between about 45° and about 90° to form an oxide material on sidewalls of the magnetic memory cell.

9. The method of claim 1 , wherein exposing the magnetic cell core material to a second beam comprises selecting a beam energy of the first beam to be greater than a beam energy of the second beam.

10. The method of claim 1 , wherein maintaining a temperature of at least one of the base material or a wafer stage underlying the base material at a temperature below about 0° C. comprises cooling the wafer stage with an ice bath, liquid carbon dioxide, or liquid nitrogen.

11. The method of claim 1 , wherein exposing the magnetic cell core material to at least a first beam comprises exposing the magnetic cell core material to a first beam consisting essentially of an oxygen-containing gas.

12. A method of forming an array of magnetic memory cells, the method comprising:

forming a stack of magnetic materials comprising a first magnetic material over a base material, a tunnel barrier material over the first magnetic material, and at least a second magnetic material over the tunnel barrier material;

exposing the stack of magnetic materials to a first beam comprising at least one noble gas at a beam angle between about 0° and about 45° while maintaining a temperature of the base material or a wafer stage on which the base material is disposed below about 0° C. to remove portions of the stack and form a plurality of magnetic memory cells; and

exposing the stack of magnetic materials to a second beam comprising an oxygen-containing gas to form an oxide material on the stack of magnetic materials.

13. The method of claim 12 , further comprising selecting the first beam to comprise the at least one noble gas and at least one oxygen-containing gas.

14. The method of claim 12 , wherein exposing the stack of magnetic materials to a second beam comprises exposing the plurality of magnetic memory cells to a second beam comprising at least one oxygen-containing gas and at least one noble gas, the second beam having a beam angle between about 45° and about 90° to form the oxide material.

15. The method of claim 12 , further comprising selecting a beam angle of the second beam to be greater than the beam angle of the first beam.

16. The method of claim 12 , further comprising selecting a beam energy of the second beam to be less than a beam energy of the first beam.

17. The method of claim 12 , further comprising maintaining a temperature of the base material or the wafer stage at a temperature below about 0° C. while exposing the plurality of magnetic memory cells to the second beam.

18. The method of claim 12 , wherein maintaining a temperature of the base material or a wafer stage on which the base material is disposed below about 0° C. comprises selecting the temperature to be less than about −50° C.

19. The method of claim 12 , wherein forming an oxide material on the stack of magnetic materials comprises forming the oxide material on sidewalls of the stack to comprise a metal oxide of a material in contact with the oxide material.