Method to reduce dislocation density in silicon using stress
A crystalline material structure with reduced dislocation density and method of producing same is provided. The crystalline material structure is annealed at temperatures above the brittle-to-ductile transition temperature of the crystalline material structure. One or more stress elements are formed on the crystalline material structure so as to annihilate dislocations or to move them into less harmful locations.
1. A method of reducing dislocation density in a crystalline material structure, comprising:
annealing said crystalline material structure at temperatures above the brittle-to-ductile transition temperature of said crystalline material; and
forming one or more stress states en said crystalline material structure so as to annihilate dislocations or to move them into less harmful locations.
2. The method of claim 1 , wherein the crystalline material comprises a semiconductor.
3. The method of claim 2 , wherein the semiconductor crystalline material comprises silicon.
4. The method of claim 3 , wherein the crystalline silicon material comprises multicrystalline silicon.
5. The method of claim 1 , wherein the crystalline material is a wafer, ribbon, block, or ingot.
6. The method of claim 1 , wherein the one or more stress states comprise mechanical stresses.
7. The method of claim 1 , wherein the stresses comprise normal stresses.
8. The method of claim 1 , wherein the stresses comprise compressive stresses.
9. The method of claim 1 , wherein the stresses comprise shear stresses.
10. The method of claim 1 , wherein the stresses comprise a normal stress gradient.
11. The method of claim 1 , wherein the stresses comprise a shear stress gradient.
12. The method of claim 1 , wherein the stresses are applied with physical contact.
13. The method of claim 1 , wherein the stress are applied without physical contact.
14. The method of claim 1 , wherein the one or more stress states comprise residual stresses.
15. The method of claim 1 , wherein the one or more stress states comprise cyclic stresses.
16. The method of claim 1 , wherein the cyclic stresses comprises non-linear thermal gradients to create stress via uneven thermal expansion.
17. The method of claim 16 , wherein the non-linear stress gradients are formed thermally or mechanically or through photons.
18. The method of claim 16 , wherein the cyclic stresses comprise a sample being placed in an environment where temperature fluctuates.
19. The method of claim 16 , wherein the cyclic stresses comprise exposing a sample being moved between environments of different set temperatures.
20. The method of claim 1 , wherein said crystalline material is utilized in a solar cell.
21. A semiconductor structure with reduced dislocation density comprising:
a crystalline material structure being annealed at temperatures above the brittle-to-ductile transition temperature of said crystalline material structure, and
one or more stress states formed on said crystalline material structure so as to annihilate dislocations or to move them into less harmful locations.
22. The semiconductor structure of claim 21 , wherein the crystalline material comprises a semiconductor.
23. The semiconductor structure of claim 22 , wherein the semiconductor crystalline material comprises silicon.
24. The semiconductor structure of claim 23 , wherein the semiconductor silicon material comprises multicrystalline silicon.
25. The semiconductor structure of claim 21 , wherein the crystalline material is a wafer, ribbon, block or ingot.
26. The semiconductor structure of claim 21 , wherein the one or more stress elements comprise mechanical stresses.
27. The semiconductor structure of claim 21 , wherein the stresses comprise normal stresses.
28. The semiconductor structure of claim 21 , wherein the stresses comprise compressive stresses.
29. The semiconductor structure of claim 21 , wherein the stresses comprise shear stresses.
30. The semiconductor structure of claim 21 , wherein the stresses comprise a normal stress gradient.
31. The semiconductor structure of claim 21 , wherein the stresses comprise a shear stress gradient.
32. The semiconductor structure of claim 21 , wherein the stresses are applied with physical contact.
33. The semiconductor structure of claim 21 , where in the stress are applied without physical contact.
34. The semiconductor structure of claim 21 , wherein the one or more stress states comprise residual stresses.
35. The semiconductor structure of claim 21 , wherein the one or more stress states comprise cyclic stresses.
36. The semiconductor structure of claim 21 , wherein the cyclic stresses comprises non-linear thermal gradients to create shear stress via uneven thermal expansion.
37. The semiconductor structure of claim 36 , wherein the non-linear gradients are foamed thermany or mechanically or through photons.
38. The semiconductor structure of claim 36 , wherein the cyclic stresses comprises exposing a sample being placed in an environment where temperature fluctuates.
39. The semiconductor structure of claim 36 , wherein the cyclic annealing comprises exposing a sample being moved between environments of different set temperatures.
40. The semiconductor structure of claim 21 , wherein said crystalline material is utilized in a solar cell.