System and method for generating and analyzing roughness measurements and their use for process monitoring and control
In one embodiment, a method includes receiving measured linescan information describing a pattern structure of a feature, applying the received measured linescan information to an inverse linescan model that relates measured linescan information to feature geometry information, and identifying, based at least in part on the applying the received measured linescan model to the inverse linescan model, feature geometry information that describes a feature that would produce a linescan corresponding to the received measured linescan information. The method also includes determining, at least in part using the inverse linescan model, feature edge positions of the identified feature, analyzing the feature edge positions to determine errors in the manufacture of the pattern structure, and controlling a lithography tool based on the analysis of the feature edge positions.
1. A method, comprising:
receiving measured linescan information describing a pattern structure of a feature;
applying the received measured linescan information to an inverse linescan model that relates measured linescan information to feature geometry information;
identifying, based at least in part on the applying the received measured linescan model to the inverse linescan model, feature geometry information that describes a feature that would produce a linescan corresponding to the received measured linescan information;
determining, at least in part using the inverse linescan model, feature edge positions of the identified feature;
analyzing the feature edge positions to determine errors in the manufacture of the pattern structure; and
controlling a lithography tool based on the analysis of the feature edge positions.
2. The method of claim 1 , wherein the lithography tool is controlled by making an adjustment in at least one of focus and exposure dose during the printing of a pattern structure.
3. The method of claim 1 , wherein the lithography tool is controlled to improve the uniformity of feature edge positions from wafer to wafer.
4. The method of claim 1 , wherein the lithography tool is controlled to improve the spatial uniformity of the feature edge positions across a wafer.
5. The method of claim 1 , wherein the lithography tool is controlled to improve the spatial uniformity of the feature width across a wafer.
6. The method of claim 1 , wherein the lithography tool is controlled to reduce the pattern placement error of the pattern structure.
7. The method of claim 1 , wherein the lithography tool is controlled to center the values of focus and exposure dose within the focus-exposure process window.
8. The method of claim 1 , wherein the lithography tool is controlled to increase the size of the focus-exposure process window.
9. The method of claim 1 , wherein the lithography tool is controlled to increase the throughput of the lithography tool.
10. The method of claim 1 , wherein the spatial distribution or other characteristics of the light source of the lithography tool are adjusted to reduce errors in the feature edge positions.
11. The method of claim 1 , wherein the lithography tool is controlled to improve the matching of feature edge position characteristics to other lithography tools, such as spatial signatures and pattern placement errors.
12. An edge detection system, comprising:
an imaging device configured to generate a first image of a pattern structure, wherein the first image of the pattern structure includes image noise; and
a processor, coupled to the imaging device, the processor configured to:
generate, based at least in part on the first image of the pattern structure, measured linescan information describing a pattern structure of a feature;
apply the measured linescan information to an inverse linescan model that relates measured linescan information to feature geometry information;
identify, based at least in part on the applying the measured linescan model to the inverse linescan model, feature geometry information that describes a feature that would produce a linescan corresponding to the received measured linescan information;
determine, at least in part using the inverse linescan model, feature edge positions of the identified feature;
analyze the feature edge positions to determine errors in the manufacture of the pattern structure; and
control a lithography tool based on the analysis of the feature edge positions.
13. The edge detection system of claim 12 , wherein the lithography tool is controlled by making an adjustment in at least one of focus and exposure dose during the printing of a pattern structure.
14. The edge detection system of claim 12 , wherein the lithography tool is controlled to improve the uniformity of feature edge positions from wafer to wafer.
15. The edge detection system of claim 12 , wherein the lithography tool is controlled to improve the spatial uniformity of the feature edge positions across a wafer.
16. The edge detection system of claim 12 , wherein the lithography tool is controlled to improve the spatial uniformity of the feature width across a wafer.
17. The edge detection system of claim 12 , wherein the lithography tool is controlled to reduce the pattern placement error of the pattern structure.
18. The edge detection system of claim 12 , wherein the lithography tool is controlled to center the values of focus and exposure dose within the focus-exposure process window.
19. The edge detection system of claim 12 , wherein the lithography tool is controlled to improve the matching of feature edge position characteristics to other lithography tools, such as spatial signatures and pattern placement errors.
20. A tangible, non-transitory computer-readable medium storing instructions that, when executed, cause a processing device to:
obtain a first image of a pattern structure, wherein the first image of the pattern structure includes image noise;
generate, based at least in part on the first image of the pattern structure, measured linescan information describing a pattern structure of a feature;
apply the measured linescan information to an inverse linescan model that relates measured linescan information to feature geometry information;
identify, based at least in part on the applying the measured linescan model to the inverse linescan model, feature geometry information that describes a feature that would produce a linescan corresponding to the received measured linescan information;
determine, at least in part using the inverse linescan model, feature edge positions of the identified feature;
analyze the feature edge positions to determine errors in the manufacture of the pattern structure; and
control a lithography tool based on the analysis of the feature edge positions.