Determining wafer orientation in spectral imaging
Devices and methods for determining wafer orientation in spectral imaging are described. The devices and methods generate an image of a wafer that includes at least one spectral dimension. One or more properties are determined from the spectral dimension, and a map is generated based on the property. The generated map is compared to at least one other map, and data or information of the comparison is used to locate a region of the wafer, for example a measurement pad or other structure.
1. A method comprising:
generating an image of a wafer that includes at least one spectral dimension;
determining at least one property from the spectral dimension;
generating a map based on the property;
comparing the map to at least one other map; and
locating a region of the wafer using data of the comparing.
2. The method of claim 1 , wherein the property includes a film stack property of a film of the wafer.
3. The method of claim 1 , wherein the property is film thickness of a film of the wafer.
4. The method of claim 1 , wherein the map is a goodness-of-fit (GOF) map of the spectral dimension.
5. The method of claim 1 , wherein the map is a two-dimensional map.
6. The method of claim 1 , wherein the map corresponds to a portion of a surface of the wafer.
7. The method of claim 1 , wherein the other map is a goodness-of-fit map.
8. The method of claim 1 , wherein the comparing comprises comparing the map to goodness-of-fit (GOF) criteria.
9. The method of claim 1 , wherein the image is a two-dimensional image.
10. The method of claim 1 , wherein the image includes an image of a portion of a surface of the wafer.
11. The method of claim 1 , further comprising generating the other map by generating a model of reflectance spectra of the wafer as a film stack.
12. The method of claim 1 , wherein the comparing includes pattern recognition.
13. The method of claim 1 , wherein the region includes a measurement pad.
14. The method of claim 1 , further comprising determining wafer orientation using data of the comparing.
15. The method of claim 1 , wherein the wafer includes at least one thin film on a substrate.
16. A system comprising:
an imaging spectrometer configured to determine a reflectance spectrum for one or more spatial locations of a film of the wafer using reflected light of the wafer;
an imager configured to generate an image of an area of the film, the image including a spectral dimension; and
a processor configured to determine from the image at least one property of the film and generate a map based on the property, and locate a pre-specified region of the wafer using data of a comparison between the map and a goodness-of-fit map.
17. The system of claim 16 , wherein the reflected light is reflected from a one-dimensional pattern of spatial locations on the film.
18. The system of claim 17 , wherein the imager is further configured to:
generate reflectance spectra for a plurality of one-dimensional patterns of the spatial locations along the film using the reflectance spectrum for each spatial location;
aggregate the reflectance spectra to generate another reflectance spectra for a two-dimensional area on the film.
19. The system of claim 16 , further comprising a translation mechanism for translating the film relative to the spectrometer.
20. The system of claim 16 , wherein the comparison includes pattern recognition.
21. The system of claim 16 , wherein the pre-specified region includes a measurement pad.
22. The system of claim 16 , wherein the processor is configured to determine orientation of the wafer using data of the comparison.
23. The system of claim 16 , wherein the property includes a film stack property of a film of the wafer.
24. The system of claim 16 , wherein the property is film thickness of a film of the wafer.
25. The system of claim 16 , wherein the map is a goodness-of-fit (GOF) map of the spectral dimension.
26. The system of claim 16 , wherein the map is a two-dimensional map.
27. The system of claim 16 , wherein the image is a two-dimensional image.
28. The system of claim 16 , wherein the wafer includes at least one thin film on a substrate.
29. Machine readable media including executable instructions that when executed in a processing system:
generate an image of a wafer that includes at least one spectral dimension;
determine at least one property from the spectral dimension;
generate a map based on the property;
compare the map to at least one other map; and
locate a region of the wafer using data of the comparing.
30. The machine readable media of claim 29 , wherein the property includes a film stack property of a film of the wafer.
31. The machine readable media of claim 29 , wherein the map is a goodness-of-fit (GOF) map of the spectral dimension.
32. The machine readable media of claim 29 , wherein the map corresponds to a portion of a surface of the wafer.
33. The machine readable media of claim 29 , wherein comparing the map to at least one other map comprises comparing the map to goodness-of-fit (GOF) criteria.
34. The machine readable media of claim 29 , wherein the image includes an image of a portion of a surface of the wafer.
35. The machine readable media of claim 29 , wherein the comparing the map to at least one other map comprises pattern recognition.
36. The machine readable media of claim 29 , wherein the region includes a structure of the wafer.
37. The machine readable media of claim 29 , wherein execution of the executable instructions in a processing system determines wafer orientation using data of the comparing.