Method and apparatus for analyzing an image of a microlithographic microstructured component

1 . A method for analyzing an image of a microlithographic microstructured component, wherein in the image each of a multiplicity of pixels is assigned in each case an intensity value, wherein the method comprises the steps of:

isolating a plurality of edge fragments in the image;

classifying each of the isolated edge fragments either as a relevant edge fragment or as an irrelevant edge fragment, wherein the relevant edge fragment represents a boundary between a first type of region and a second type of region, and the irrelevant edge fragment does not represent a boundary between the first type of region and the second type of region; and

ascertaining contiguous segments in the image based on the relevant edge fragments;

wherein for the ascertainment of contiguous segments pixels located in the surrounding area of in each case one edge fragment are assigned, in a spacing-based manner, to a respective one of the two regions that are separated by this edge fragment;

wherein for the ascertaining of contiguous segments pixels located in interruption regions between successive edge fragments are assigned, in a spacing-based manner, to the one or to the other of the adjoining regions, wherein an existing edge fragment is complemented on both sides respectively with a further virtual edge having a width of one pixel, and it is ascertained for an edge fragment that is located closest in the interruption region whether it lies closer to the one or to the other of the adjoining regions.

2 . The method of claim 1 , wherein the classifying of each of the isolated edge fragments is effected based on an average intensity gradient of isolated edge fragments.

3 . The method of claim 2 , wherein each of the isolated edge fragments is classified based on whether the respective average intensity gradient of an isolated edge fragment exceeds a threshold value.

4 . The method of claim 3 , wherein some of the isolated edge fragments are not taken into account for the defining of the threshold value, wherein the isolated edge fragments not taken into account for the defining of the threshold value comprise at least one of particularly short edge fragments, particularly high-contrast edge fragments, particularly low-contrast edge fragments, or edge fragments located near a comparatively brighter edge fragment.

5 . The method of claim 1 , wherein the contiguous segments are ascertained without prior closing of gaps present between the edge fragments.

6 . The method of claim 1 , wherein furthermore irrelevant edge fragments are eliminated during the ascertainment of contiguous segments.

7 . The method of claim 1 , wherein edge fragments are combined into object edges and the edge coordinates are computed in a subpixel-wise manner after the ascertainment of contiguous segments.

8 . The method of claim 7 , wherein irrelevant object edges are eliminated after said combination of edge fragments into object edges.

9 . The method of claim 8 , wherein a segment image is computed after said elimination of irrelevant object edges.

10 . The method of claim 1 , wherein before a plurality of edge fragments are isolated, image pre-processing for reducing a noise component is carried out.

11 . The method of claim 1 , wherein isolating a plurality of edge fragments comprises eliminating branches having lengths that fall below a specified value.

12 . The method of claim 1 , wherein isolating a plurality of edge fragments comprises eliminating intersection points at which at least three edges intersect.

13 . The method of claim 1 , wherein the image is divided by way of the segments into a total of two different regions which differ in terms of a material that is located in the respective region.

14 . The method of claim 1 , wherein the microstructured component is a mask.

15 . The method of claim 14 , wherein the mask is designed for a working wavelength of less than 250 nm.

16 . The method of claim 1 , wherein the microstructured component is a wafer.

17 . An apparatus for analyzing an image of a microlithographic microstructured component, wherein the apparatus is designed to carry out the method of claim 1 .

18 . The apparatus of claim 17 , wherein the classifying of each of the isolated edge fragments is effected based on an average intensity gradient of isolated edge fragments.

19 . An apparatus for analyzing an image of a microlithographic microstructured component, the image comprising a plurality of pixels, each pixel being assigned an intensity value, the apparatus comprising:

a storage device storing instructions;

at least one data processor configured to execute the instructions to implement a process comprising:

isolating a plurality of edge fragments in the image;

classifying each of the isolated edge fragments either as a relevant edge fragment or as an irrelevant edge fragment, wherein the relevant edge fragment represents a boundary between a first type of region and a second type of region, and the irrelevant edge fragment does not represent a boundary between the first type of region and the second type of region; and

ascertaining contiguous segments in the image based on the relevant edge fragments;

wherein for each edge fragment, pixels located in a surrounding area of the edge fragment are assigned, in a spacing-based manner, to a respective one of two regions that are separated by the edge fragment;

wherein for the ascertaining of contiguous segments pixels located in interruption regions between successive edge fragments are assigned, in a spacing-based manner, to the one or to the other of the adjoining regions, wherein an existing edge fragment is complemented on both sides respectively with a further virtual edge having a width of one pixel, and it is ascertained for an edge fragment that is located closest in the interruption region whether it lies closer to the one or to the other of the adjoining regions.

20 . The apparatus of claim 19 in which the classifying of each of the isolated edge fragments is effected based on an average intensity gradient of isolated edge fragments.

21 . The method of claim 1 , comprising modifying the microstructured component based on an analysis of the contiguous segments in the image.

22 . The method of claim 1 , comprising identifying errors in the microstructured component based on an analysis of the contiguous segments in the image, and modifying the microstructured component to correct the errors.

23 . The method of claim 14 , wherein the mask is designed for a working wavelength of less than 200 nm.

24 . The method of claim 14 , wherein the mask is designed for a working wavelength of less than 15 nm.

25 . The method of claim 1 wherein the relevant edge fragment represents a boundary between a coated region and an uncoated region, and the irrelevant edge fragment does not represent a boundary between a coated region and an uncoated region.

26 . The method of claim 1 wherein the relevant edge fragment represents a boundary between a structure-carrying region and a structure-less region, and the irrelevant edge fragment does not represent a boundary between a structure-carrying region and a structure-less region.

27 . The apparatus of claim 17 wherein the relevant edge fragment represents a boundary between a coated region and an uncoated region, and the irrelevant edge fragment does not represent a boundary between a coated region and an uncoated region.

28 . The apparatus of claim 17 wherein the relevant edge fragment represents a boundary between a structure-carrying region and a structure-less region, and the irrelevant edge fragment does not represent a boundary between a structure-carrying region and a structure-less region.

29 . The apparatus of claim 19 wherein the relevant edge fragment represents a boundary between a coated region and an uncoated region, and the irrelevant edge fragment does not represent a boundary between a coated region and an uncoated region.

30 . The apparatus of claim 19 wherein the relevant edge fragment represents a boundary between a structure-carrying region and a structure-less region, and the irrelevant edge fragment does not represent a boundary between a structure-carrying region and a structure-less region.

31 . The method of claim 1 wherein ascertained contiguous segments do not include irrelevant edge fragments.