Method of making a CIG target by spray forming

1. A method of making a sputtering target, comprising:

providing a backing structure, and

forming a copper indium gallium sputtering target material on the backing structure by spray forming wherein:

from 0% to 10% of primary phase regions in the sputtering target material are of a size greater than 30 μm in any random 1 cm by 1 cm area of the sputtering target;

an average primary phase region in the sputtering target material is of a size not greater than 10 μm; and

the sputtering target material has an overall uniform composition.

2. A method as claimed in claim 1 , wherein the sputtering target material is provided in a liquid state from a tundish into at least one gas jet to create a liquid droplet spray.

3. A method as claimed in claim 2 , wherein the sputtering target material is formed by spraying the entire sputtering target material directly onto the backing structure having a planar shape.

4. A method as claimed in claim 2 , wherein the sputtering target material is formed by spraying the entire sputtering target material directly onto the backing structure comprising a cylindrical backing structure to form a rotary sputtering target.

5. A method as claimed in claim 4 , wherein the sputtering target material droplet spray is provided onto the cylindrical backing structure that is rotated about its axis and moved parallel to its axis.

6. A method as claimed in claim 4 , wherein the sputtering target material droplet spray is provided from the tundish through a slit shaped opening having about a same length as an axial length of the cylindrical backing structure.

7. A method as claimed in claim 6 , wherein the sputtering target material droplet spray provided from the tundish has about the same length as the axial length of the cylindrical backing structure.

8. A method as claimed in claim 6 , wherein the cylindrical backing structure rotates about its axis but is not moved along its axis while the sputtering target material droplet spray is provided onto the backing structure.

9. A method as claimed in claim 6 , wherein the slit shaped opening has a variable width such that more sputtering target material is deposited on the backing structure at a location corresponding to a wider opening width than at a location corresponding to a narrower opening width.

10. A method as claimed in claim 2 , further comprising heating the backing structure before the sputtering target material droplet spray is provided onto the backing structure.

11. A method as claimed in claim 2 , further comprising cooling the backing structure at least one of during and after the sputtering target material droplet spray is provided onto the backing structure.

12. A method as claimed in claim 2 , wherein the liquid sputtering target material is provided from the tundish in a controlled environment.

13. A method as claimed in claim 2 , wherein the sputtering target material droplet spray and the backing structure are contained within a controlled environment.

14. A method as claimed in claim 2 , further comprising adding metallic sodium or a sodium compound to the liquid copper indium gallium sputtering target material.

15. A method as claimed in claim 2 , further comprising providing solid particles into the liquid droplet spray.

16. A method as claimed in claim 15 , wherein the solid particles comprise sodium containing particles which are provided into the spray to create a substantially homogenous distribution of sodium containing particles within the target.

17. A method as claimed in claim 1 , wherein the sputtering target material has an overall uniform composition of about 29-41 wt % copper, about 36-62 wt % indium, and about 8-25 wt % gallium.

18. A method as claimed in claim 1 , wherein the sputtering target material has an overall uniform composition of about 8-15 wt % copper, about 55-80 wt % indium, and about 10-25 wt % gallium.

19. A method as claimed in claim 1 , wherein the sputtering target material is formed by rapid solidification of the liquid sputtering target material on the backing structure at a rate of approximately 100° C./s, or greater.

20. A method as claimed in claim 1 , wherein the target material further comprises a metallic Na or Na-containing compound, and the target material contains 0.1 wt % to 1.0 wt % Na.

21. A method of making a sputtering target, comprising:

providing a backing structure, and

forming a copper indium gallium sputtering target material on the backing structure by spray forming, wherein:

from 0% to 10% of primary phase regions in the sputtering target material are of a size greater than 10 μm in any random 1 cm by 1 cm area of the sputtering target;

an average primary phase region in the sputtering target material is of a size between 0.5 and 10 μm; and

the sputtering target material has an overall uniform composition.

22. A method of making a sputtering target, comprising:

providing a backing structure, and

forming a copper indium gallium sputtering target material on the backing structure by spray forming, wherein:

from 1% to 5% of primary phase regions in the sputtering target material are of a size greater than 10 μm in any random 1 cm by 1 cm area of the sputtering target;

an average primary phase region in the sputtering target material is of a size between 1 and 5 μm; and

the sputtering target material has an overall uniform composition.