Metrology and control of overlay and edge placement errors
An overlay metrology system may include a controller to generate optical tool error adjustments for a hybrid overlay target including optically-resolvable features and device-scale features by measuring a difference between an optical overlay measurement based on the optically-resolvable features and a device-scale overlay measurement based on the device-scale features, generate target-to-device adjustments for the hybrid overlay target based on positions of features within the device area, determine device-relevant overlay measurements for one or more locations in the device area based on at least one of the optical overlay measurement, the optical tool error adjustments, or the target-to-device adjustments, and provide overlay correctables for the device area to a lithography tool to modify exposure conditions for at least one subsequent exposure based on the device-relevant overlay measurements.
1. A metrology system comprising:
a controller, the controller including one or more processors configured to execute program instructions configured to cause the one or more processors to:
generate optical tool error adjustments for a hybrid overlay target including optically-resolvable features and device-scale features, by measuring a difference between an optical overlay measurement based on the optically-resolvable features and a device-scale overlay measurement based on the device-scale features;
generate target-to-device adjustments for the hybrid overlay target based on positions of features within a device area;
determine device-relevant overlay measurements for one or more locations in the device area based on at least one of the optical overlay measurement, the optical tool error adjustments, or the target-to-device adjustments; and
provide overlay correctables for the device area to a lithography tool to modify exposure conditions for at least one subsequent exposure based on the device-relevant overlay measurements.
2. The metrology system of claim 1 , wherein the positions of the features within the device area for determining the target-to-device adjustments comprise:
pattern placement distances between the hybrid overlay target and the features within the device area for two or more layers of the sample.
3. The metrology system of claim 2 , wherein the pattern placement distances between the hybrid overlay target and the features within the device area are received from an edge-placement metrology tool comprising:
a translation stage for securing the sample, wherein the translation stage has a range of motion at least equal to a separation between the hybrid overlay target and the device-scale features within the device area; and
an imaging system, wherein the pattern placement distances include distances measured by the translation stage between the hybrid overlay target and the device-scale features.
4. The metrology system of claim 3 , wherein the edge-placement metrology tool is integrated within at least one of an optical metrology tool or a particle-beam metrology tool.
5. The metrology system of claim 1 , wherein the positions of the features within the device area for determining the target-to-device adjustments comprise:
overlay measurements within the device area.
6. The metrology system of claim 5 , wherein the overlay measurements within the device area comprise:
overlay measurements of device features within the device area.
7. The metrology system of claim 5 , wherein the overlay measurements within the device area comprise:
overlay measurements of device-scale overlay targets within the device area.
8. The metrology system of claim 1 , wherein the optically-resolvable features are segmented to include periodically-distributed features providing multiple measurement locations, wherein the optical overlay measurement includes overlay determined based on the multiple measurement locations.
9. The metrology system of claim 1 , wherein the device-scale features are segmented to include periodically-distributed features providing multiple measurement locations, wherein the device-scale overlay measurement includes overlay determined based on the multiple measurement locations.
10. The metrology system of claim 1 , wherein the controller receives the optical overlay measurement from an optical metrology tool.
11. The metrology system of claim 10 , wherein the optical metrology tool is an image-based overlay tool, wherein the optical overlay measurement is an image-based overlay measurement.
12. The metrology system of claim 10 , wherein the optical metrology tool is a scatterometry-based overlay tool, wherein the optical overlay measurement is a scatterometry-based overlay measurement.
13. The metrology system of claim 1 , wherein the controller receives the device-scale overlay measurement from a particle-beam metrology tool.
14. The metrology system of claim 13 , wherein the particle-beam metrology tool comprises:
a scanning electron microscope metrology tool.
15. The metrology system of claim 14 , wherein the scanning electron microscope metrology tool comprises:
a critical-dimension scanning electron microscope.
16. The metrology system of claim 13 , wherein the particle-beam metrology tool comprises:
a focused ion beam metrology tool.
17. The metrology system of claim 1 , wherein the device area is a die of the sample.
18. The metrology system of claim 1 , wherein the hybrid overlay target is located in a scribe line of the sample.
19. The metrology system of claim 1 , wherein at least one of the optical overlay measurement of the hybrid overlay target, the device-scale overlay measurement of the hybrid overlay target, or measurements of the positions of the features within the device area for determining the target-to-device adjustments comprise:
after development inspection data.
20. The metrology system of claim 1 , wherein at least one of the optical overlay measurement of the hybrid overlay target, the device-scale overlay measurement of the hybrid overlay target, or measurements of the positions of the features within the device area for determining the target-to-device adjustments comprise:
after etch inspection data.
21. The metrology system of claim 1 , wherein the optically-resolvable features and the device-scale features of the hybrid overlay target are physically separated.
22. The metrology system of claim 1 , wherein at least some of the optically-resolvable features are segmented, wherein the device-scale features form segments of the optically-resolvable features.
23. The metrology system of claim 1 , wherein the device-scale features of the hybrid overlay target are compatible with design rules of device features within the device area.
24. The metrology system of claim 1 , wherein the metrology system is configured as an overlay metrology system.
25. The metrology system of claim 1 , wherein the metrology system is configured as an edge placement metrology system.
26. A metrology system comprising:
an optical metrology tool configured to generate an optical overlay measurement based on optically-resolvable features of a hybrid overlay target on a sample;
a particle-beam metrology tool configured to generate a device-scale overlay measurement based on device-scale features of the hybrid overlay target;
an edge-placement metrology tool configured to measure positions of features within a device area of the sample with respect to the hybrid overlay target; and
a controller communicatively coupled to the optical metrology tool and the particle-beam metrology tool, the controller including one or more processors configured to execute program instructions configured to cause the one or more processors to:
generate optical tool error adjustments for the hybrid overlay target based on a difference between the optical overlay measurement received by the optical metrology tool and the device-scale overlay measurement received by the particle-beam metrology tool;
generate target-to-device adjustments for the hybrid overlay target based on positions of features within the device area received by the edge-placement metrology tool;
determine device-relevant overlay measurements for one or more locations in the device area based on at least one of the optical overlay measurement, the optical tool error adjustments, or the target-to-device adjustments; and
provide overlay correctables for the device area to a lithography tool to modify exposure conditions for at least one subsequent exposure based on the device-relevant overlay measurements.
27. The metrology system of claim 26 , wherein the positions of the features within the device area for determining the target-to-device adjustments comprise:
pattern placement distances between the hybrid overlay target and the features within the device area for two or more layers of the sample.
28. The metrology system of claim 27 , wherein the edge-placement metrology tool comprises:
a translation stage for securing the sample, wherein the translation stage has a range of motion at least equal to a separation between the hybrid overlay target and the device-scale features within the device area; and
an imaging system, wherein the pattern placement distances include distances measured by the translation stage between the hybrid overlay target and the device-scale features.
29. The metrology system of claim 26 , wherein the edge-placement metrology tool is integrated within at least one of the optical metrology tool or the particle-beam metrology tool.
30. The metrology system of claim 26 , wherein the positions of the features within the device area for determining the target-to-device adjustments further comprise:
overlay measurements within the device area measured using at least one of the optical metrology tool or the particle-beam metrology tool.
31. The metrology system of claim 30 , wherein the overlay measurements within the device area comprise:
overlay measurements of device features within the device area.
32. The metrology system of claim 30 , wherein the overlay measurements within the device area comprise:
overlay measurements of device-scale overlay targets within the device area.
33. The metrology system of claim 26 , wherein the optically-resolvable features are segmented to include periodically-distributed features providing multiple measurement locations, wherein the optical overlay measurement includes overlay determined based on the multiple measurement locations.
34. The metrology system of claim 26 , wherein the device-scale features are segmented to include periodically-distributed features providing multiple measurement locations, wherein the device-scale overlay measurement includes overlay determined based on the multiple measurement locations.
35. The metrology system of claim 26 , wherein the optical metrology tool is an image-based overlay tool, wherein the optical overlay measurement is an image-based overlay measurement.
36. The metrology system of claim 26 , wherein the optical metrology tool is a scatterometry-based overlay tool, wherein the optical overlay measurement is a scatterometry-based overlay measurement.
37. The metrology system of claim 26 , wherein the particle-beam metrology tool comprises:
a scanning electron microscope metrology tool.
38. The metrology system of claim 37 , wherein the scanning electron microscope metrology tool comprises:
a critical-dimension scanning electron microscope.
39. The metrology system of claim 26 , wherein the particle-beam metrology tool comprises:
a focused ion beam metrology tool.
40. The metrology system of claim 26 , wherein the metrology system is configured as an overlay metrology system.
41. The metrology system of claim 26 , wherein the metrology system is configured as an edge placement metrology system.
42. A metrology method comprising:
measuring an optical overlay of a hybrid overlay target on a sample based on optically-resolvable elements of the hybrid overlay target;
measuring a device-scale overlay of the hybrid overlay target based on device-scale elements of the hybrid overlay target;
determining optical tool error adjustments for the hybrid overlay target based on a difference between the optical overlay and the device-scale overlay;
measuring target-to-device placement errors for one or more features within a device area with respect to the hybrid overlay target;
generating one or more target-to-device adjustments for the device area based on the target-to-device placement errors;
determining device-relevant overlay measurements for one or more positions within the device area based on the optical overlay, the optical tool error adjustments, and the target-to-device adjustments; and
providing overlay correctables for the device area to a lithography tool to modify exposure conditions for at least one subsequent sample based on the device-relevant overlay measurements.