Methods and systems for creating or performing a dynamic sampling scheme for a process during which measurements are performed on wafers
Various methods and systems for creating or performing a dynamic sampling scheme for a process during which measurements are performed on wafers are provided. One method for creating a dynamic sampling scheme for a process during which measurements are performed on wafers includes performing the measurements on all of the wafers in at least one lot at all measurement spots on the wafers. The method also includes determining an optimal sampling scheme, an enhanced sampling scheme, a reduced sampling scheme, and thresholds for the dynamic sampling scheme for the process based on results of the measurements. The thresholds correspond to values of the measurements at which the optimal sampling scheme, the enhanced sampling scheme, and the reduced sampling scheme are to be used for the process.
1. A system operable to pattern a wafer, comprising:
a measurement tool operable to perform measurements on the wafer, wherein results of the measurements comprise stress metrology data;
one or more processors operable to:
model deformation of the wafer based on the results of the measurements; and
alter one or more parameters of a patterning process based on the deformation of the wafer; and
a patterning tool operable to pattern the wafer using the patterning process after the one or more parameters of the patterning process have been altered to produce a first patterned wafer, wherein the one or more processors are further operable to model the deformation by estimating the deformation the wafer will have when the wafer is placed on a stage of the patterning tool by modeling how the deformation of the wafer interacts with the stage of the patterning tool.
2. The system of claim 1 , wherein the measurement tool is further operable to perform the measurements by performing the measurements at substantially all measurement spots on the wafer.
3. The system of claim 1 , wherein the results of the measurements further comprise shape metrology data.
4. The system of claim 1 , wherein the results of the measurements further comprise overlay metrology data.
5. The system of claim 1 , wherein the one or more processors are further operable to model the deformation by simulating effects of the deformation on patterning of a design pattern on the wafer.
6. The system of claim 5 , wherein the measurement tool is further operable to perform additional measurements on the first patterned wafer, wherein the one or more processors are further operable to alter the one or more parameters of the patterning tool based on results of the additional measurements, and wherein after the one or more parameters of the patterning tool are altered based on the results of the additional measurements, the patterning tool is further operable to pattern a second wafer to produce a second patterned wafer.
7. The system of claim 6 , wherein the results of the additional measurements comprise overlay metrology data.
8. The system of claim 6 , wherein the results of the additional measurements comprise focus metrology data.
9. The system of claim 6 , wherein the results of the additional measurements comprise dose metrology data.
10. The system of claim 6 , wherein the first and second patterned wafers are in the same lot.
11. The system of claim 6 , wherein the first and second patterned wafers are in different lots.
12. The system of claim 1 , wherein the measurement tool is configured as an interferometer.
13. The system of claim 1 , wherein the measurement tool comprises optical interferometers configured for simultaneous measurements of displacement of both sides of the wafer.
14. The system of claim 1 , wherein during the measurements, the wafer is free of effects from outer forces because the wafer stands in an upright position.
15. The system of claim 1 , wherein the measurement tool is further operable to support the wafer in a substantially vertical direction during the measurements.
16. The system of claim 1 , further comprising a processing tool configured to perform a fabrication process on the wafer before the measurements are performed on the wafer.
17. The system of claim 16 , wherein the measurement tool is further operable to perform additional measurements on the wafer prior to the fabrication process, wherein the one or more processors are further operable to model additional deformation of the wafer based on results of the additional measurements and to alter one or more parameters of the fabrication process based on the additional deformation of the wafer, and wherein the processing tool is further operable to perform the fabrication process on the wafer after the one or more parameters of the fabrication process have been altered.
18. A system operable to process a wafer, comprising:
a measurement tool operable to perform measurements on the wafer, wherein results of the measurements comprise stress metrology data;
one or more processors operable to:
model deformation of the wafer based on the results of the measurements; and
alter one or more parameters of a fabrication process based on the deformation of the wafer; and
a processing tool operable to perform the fabrication process on the wafer after the one or more parameters of the fabrication process have been altered, wherein the one or more processors are further operable to model the deformation by estimating the deformation the wafer will have when the wafer is placed on a stage of the processing tool by modeling how the deformation of the wafer interacts with the stage of the processing tool.
19. The system of claim 18 , wherein the measurement tool is further operable to perform additional measurements on the wafer after the fabrication process is performed on the wafer, and wherein the one or more processors are further operable to model additional deformation of the wafer based on results of the additional measurements.