Determining metrics for a portion of a pattern on a substrate
Systems and methods for determining one or more characteristic metrics for a portion of a pattern on a substrate are described. Pattern information for the pattern on the substrate is received. The pattern on the substrate has first and second portions. The first portion of the pattern is blocked, for example with a geometrical block mask, based on the pattern information, such that the second portion of the pattern remains unblocked. The one or more metrics are determined for the unblocked second portion of the pattern. In some embodiments, the first and second portions of the pattern correspond to different exposures in a semiconductor lithography process. The semiconductor lithography process may be a multiple patterning technology process, for example, such as a double patterning process, a triple patterning process, or a spacer double patterning process.
1. A non-transitory computer readable medium having instructions therein or thereon, the instructions, when executed by a computer system, configured to cause the computer system to at least:
receive pattern information for a device-type pattern on a substrate, the pattern on the substrate having first and second portions;
block, based on the pattern information, the first portion such that the second portion remains unblocked; and
determine one or more metrics for the unblocked second portion.
2. The medium of claim 1 , wherein the one or more metrics comprise a critical dimension and/or edge placement error.
3. The medium of claim 1 , wherein the instructions configured to cause the computer system to determine the one or more metrics for the unblocked second portion are further configured to cause the computer system to:
align and average images of the pattern on the substrate;
perform contour extraction on an averaged image; and
align an extracted contour with the pattern information for the pattern on the substrate, the alignment performed for both portions of the pattern, including the blocked first portion and unblocked second portion.
4. The medium of claim 3 , wherein the instructions configured to cause the computer system to determine the one or more metrics for the unblocked second portion are further configured to cause the computer system to:
generate one or more gauges in the contour for the unblocked second portion of the pattern; and
measure the one or more gauges, the one or more gauges specifying the one or more metrics for the unblocked second portion.
5. The medium of claim 3 , wherein the first and second portions of the pattern are merged, wherein the images are scanning electron microscope (SEM) images comprising the merged first and second portions of the pattern on the substrate, and wherein the instructions configured to cause the computer system to determine the one or more metrics for the unblocked second portion are further configured to cause the computer system to decompose the first and second portions of the pattern in the SEM images.
6. The medium of claim 1 , wherein the instructions configured to cause the computer system to block the first portion are further configured to cause the computer system to generate a geometrical block mask for the first portion based on the pattern information.
7. The medium of claim 6 , wherein the pattern information specifies geometry of the first portion of the pattern, and wherein the instructions configured to cause the computer system to generate the mask are further configured to cause the computer system to bias the geometry of the first portion larger or smaller relative to the geometry of the first portion specified in the pattern information.
8. The medium of claim 6 , wherein the pattern information specifies geometry of the first portion of the pattern, and wherein the instructions configured to cause the computer system to generate the mask are further configured to cause the computer system to generate a first mask area by biasing the geometry of the first portion larger relative to the geometry of the first portion specified in the pattern information, generate a second mask area by biasing the geometry of the first portion smaller relative to the geometry of the first portion specified in the pattern information, and subtract the second mask area from the first mask area to generate the mask.
9. The medium of claim 6 , wherein at least a portion of the mask is further formed by a cutting layer of the pattern.
10. The medium of claim 1 , wherein the first and second portions of the pattern on the substrate are merged and correspond to different exposures in a semiconductor lithography process.
11. The medium of claim 10 , wherein the semiconductor lithography process is a multiple patterning technology process.
12. The medium of claim 6 , wherein the instructions configured to cause the computer system to block the first portion are further configured to cause the computer system to generate a geometrical block mask for the first portion further based on D2DB alignment.
13. The medium of claim 1 , wherein the instructions are further configured to cause the computer to adjust a semiconductor manufacturing process based on the one or more metrics for the unblocked second portion.
14. The medium of claim 13 , wherein the instructions configured to cause the computer system to adjust the semiconductor manufacturing process are further configured to cause the computer system to change a dimension, a shape, and/or a location of a feature in the second portion of the pattern; and/or change a mask, a dose, a focus, and/or an exposure associated with the second portion of the pattern.
15. The medium of claim 1 , wherein the instructions are further configured to cause the computer to:
unblock the first portion based on the pattern information;
block, based on the pattern information, the second portion such that the first portion remains unblocked; and
determine one or more metrics for the unblocked first portion.
16. A method comprising:
receiving pattern information for a device-type pattern on a substrate, the pattern on the substrate having first and second portions;
block, by a hardware computer system and based on the pattern information, the first portion such that the second portion remains unblocked; and
determine one or more metrics for the unblocked second portion.
17. The method of claim 16 , wherein the one or more metrics comprise a critical dimension and/or edge placement error.
18. The method of claim 16 , wherein determining the one or more metrics for the unblocked second portion comprises:
aligning and averaging images of the pattern on the substrate;
performing contour extraction on an averaged image; and
aligning an extracted contour with the pattern information for the pattern on the substrate, the aligning performed for both portions of the pattern, including the blocked first portion and unblocked second portion.
19. The method of claim 16 , wherein the blocking comprises generating a geometrical block mask for the first portion based on the pattern information.
20. The method of claim 16 , further comprising adjusting a semiconductor manufacturing process based on the one or more metrics for the unblocked second portion.