Method of determining control parameters of a device manufacturing process
A method including: obtaining an image of at least part of a substrate, wherein the image includes at least one feature of a device being manufactured in a layer on the substrate; obtaining a layout of features associated with a previous layer adjacent to the layer on the substrate; calculating one or more image-related metrics in dependence on: 1) a contour determined from the image including the at least one feature and 2) the layout; and determining one or more control parameters of a lithographic apparatus and/or one or more further processes in a manufacturing process of the device in dependence on the one or more image-related metrics, wherein at least one of the control parameters is determined to modify the geometry of the contour in order to improve the one or more image-related metrics.
1. A method for a manufacturing process of a device on a substrate, wherein the manufacturing process comprises a lithographic process of imaging a portion of a design layout onto the substrate using a lithographic apparatus and one or more further processes in the manufacturing process of the device, the method comprising:
obtaining an image of at least part of the substrate, wherein the image comprises at least one feature comprised by the device being manufactured in a layer on the substrate;
obtaining a layout of features associated with a previous layer adjacent to the layer on the substrate;
calculating one or more image-related metrics in dependence on: 1 ) a contour determined from the image comprising the at least one feature and 2 ) the layout of features; and
determining one or more control parameters of the lithographic apparatus and/or the one or more further processes in the manufacturing process of the device in dependence on the one or more image-related metrics, wherein at least one of the one or more control parameters is determined to modify the geometry of the contour in order to improve the one or more image-related metrics.
2. The method of claim 1 , wherein the one or more image-related metrics comprises an area of contact between the feature and another feature associated with the previous layer.
3. The method of claim 1 , wherein at least one control parameter of the one or more control parameters is an aberration setting of the lithographic apparatus.
4. The method of claim 3 , wherein the aberration setting is a value of astigmatism.
5. The method of claim 1 , wherein the one or more control parameters comprises a plurality of control parameters and at least two control parameters of the plurality of control parameters are co-determined.
6. The method of claim 5 , wherein the at least two control parameters are dose and astigmatism.
7. A method for a manufacturing process of a device on a substrate, wherein the manufacturing process comprises a lithographic process of imaging a portion of a design layout onto the substrate using a lithographic apparatus and one or more further processes in the manufacturing process of the device, the method comprising:
obtaining an image of at least part of the substrate, wherein the image comprises at least one feature comprised by the device being manufactured on the substrate;
calculating one or more image-related metrics in dependence on a contour determined from the image comprising the at least one feature;
determining a plurality of control parameters of the lithographic apparatus and/or the one or more further processes in the manufacturing process of the device in dependence on the one or more image-related metrics, wherein at least two control parameters of the plurality of control parameters are co-determined.
8. The method according to claim 7 , wherein co-determination of the at least two control parameters comprises determining an applied value of one of the control parameters in dependence on an applied value of another of the control parameters.
9. The method according to claim 7 , wherein co-determination of the at least two control parameters is dependent on:
the combined effect of the at least two control parameters; and/or
the interdependence of the at the least two control parameters.
10. The method according to claim 7 , wherein the co-determined control parameters comprise focus and dose.
11. The method according to claim 10 , wherein the co-determined control parameters further include overlay and/or contrast.
12. The method according to claim 7 , wherein the co-determined control parameters are determined in dependence on critical dimension variation on a small spatial scale or in dependence on both critical dimension variation on a small spatial scale and critical dimension variation on a large spatial scale.
13. The method according to claim 7 , wherein the co-determined control parameters are determined in dependence on one or more selected from: global edge placement error (EPE), local EPE, critical dimension, critical dimension uniformity, or critical dimension variation on a small spatial scale and critical dimension variation on a large spatial scale.
14. The method according to claim 7 , further comprising:
obtaining a plurality of images of the substrate; and
determining image-related metrics of features in each image.
15. The method according to claim 14 , wherein at least one of the control parameters is determined in dependence of the image-related metrics of each image as well as the dependence of the determined image-related metrics on changes of at least one control parameter.
16. The method according to claim 14 , wherein the image-related metrics include one or more selected from: sizes of block patterns in the images, differences in sizes of the block patterns in the images, differences in pitches in gratings in the images, the overall shift of a block layer with respect to grating layer, or the shift between two LELE layers.
17. The method according to claim 14 , wherein the images are of the same part of the substrate; and the images are obtained during different manufacturing processes of a layer of the substrate.
18. The method according to claim 17 , further comprising controlling proximity effects in dependence on differences between the images.
19. The method according to claim 14 , wherein the image-related metrics are obtained by:
mapping a measured image to a reference image; and/or
averaging parameters derived from lines across an image.
20. A computer program product comprising a non-transitory computer-readable medium having machine-readable instructions therein, the instructions, when executed by a computer system, configured to cause the computer system to at least:
obtain an image of at least part of a substrate, wherein the image comprises at least one feature comprised by a device being manufactured in a layer on the substrate by a manufacturing process that comprises a lithographic process of imaging a portion of a design layout onto the substrate using a lithographic apparatus and one or more further processes in the manufacturing process of the device;
obtain a layout of features associated with a previous layer adjacent to the layer on the substrate;
calculate one or more image-related metrics in dependence on: 1 ) a contour determined from the image comprising the at least one feature and 2 ) the layout;
determine one or more control parameters of the lithographic apparatus and/or the one or more further processes in the manufacturing process of the device in dependence on the one or more image-related metrics, wherein at least one of the control parameters is determined to modify the geometry of the contour in order to improve the one or more image-related metrics.