Method for designing optical lithography masks for directed self-assembly

1. A method for selecting at least one prepattern shape from a plurality of prepattern shapes, comprising:

using a computer, generating said prepattern shapes, said prepattern shapes coded as digital data, said prepattern shapes, when used in conjunction with a multi-component self-assembly material, generates a directed self-assembly pattern of inner domains surrounded by outer domains of said multi-component self-assembly material within actual prepattern shapes on a substrate, said actual prepattern shapes based on said prepattern shapes;

applying a first test to each prepattern shape of said plurality of prepattern shapes to determine a fidelity with which each prepattern shape of said plurality of prepattern shapes produces said directed self-assembly pattern when used in conjunction with a directed self-assembly process using said multi-component self-assembly material;

applying a second test to each prepattern shape of said plurality of prepattern shapes to determine a lithographic exposure latitude for each prepattern shape of said plurality of prepattern shapes; and

selecting said at least one prepattern shape of said plurality of prepattern shapes based on evaluating results of said first and second tests.

2. The method of claim 1 , further including:

calibrating said first and second tests to reduce spatial differences between prepatterns and corresponding directed-self assembled patterns by comparing actual directed-self assembled patterns fabricated using corresponding actual prepatterns in a photoresist layer to a model of generating directed self-assembly patterns from corresponding prepatterns.

3. The method of claim 1 , further comprising, for each prepattern shape of said plurality of prepattern shapes:

(i) modeling topographical patterns of said multiple components of said multi-component self-assembly material within a region bounded by corresponding prepattern shapes of said plurality of prepattern shapes;

(ii) comparing said topographical patterns to said target pattern; and

(iii) selecting at least one prepattern shape of said multiple prepattern shapes that corresponds to said target pattern to a specified degree of fidelity.

4. The method of claim 1 , further comprising:

modeling a pattern transferred by an etch process into said substrate after removing a component of said multi-component self-assembly material following self-assembly of said multi-component self-assembly material within an opening in a photoresist layer.

5. The method of claim 1 , further comprising:

designing an optical photolithographic mask, which when used in conjunction with a photolithographic process, leads to the formation of an actual prepattern in a photoresist layer formed on said substrate, said actual prepattern based on said selected prepattern.

6. The method of claim 1 , wherein said prepattern shapes are capable of being generated as said actual prepattern shapes in a photoresist layer applied to said substrate by an optical photolithographic process.

7. The method of claim 1 , wherein determining said fidelity includes comparing simulated locations and sizes of inner domains of said directed self-assembly material within said prepattern shapes to a target size and location of an inner domain of said directed self-assembly pattern.

8. The method of claim 1 , wherein determining said exposure latitude includes comparing simulated locations and sizes of inner domains of said directed self-assembly material within said prepattern shapes over a range of exposure doses applied to each of said prepattern shapes to a target size and location of an inner domain of said directed self-assembly pattern.

9. The method of claim 1 , wherein determining said exposure latitude includes comparing actual locations and sizes of inner domains of said directed self-assembly material within said actual prepattern shapes printed over a range of exposure doses applied to each of said prepattern shapes to a target size and location of an inner domain of said directed self-assembly pattern.

10. The method of claim 1 , wherein determining said fidelity includes comparing simulated locations, numbers and sizes of inner domains of said directed self-assembly material within said prepattern shapes to target sizes, numbers and locations of inner domains of said directed self-assembly pattern.

11. The method of claim 1 , wherein determining said exposure latitude includes comparing simulated locations, numbers and sizes of inner domains of said directed self-assembly material within said prepattern shapes over a range of exposure doses applied to each of said prepattern shapes to target sizes, numbers and locations of inner domains of said directed self-assembly pattern.

12. The method of claim 1 , wherein determining said exposure latitude includes comparing actual locations, numbers and sizes of inner domains of said directed self-assembly material within said prepattern shapes printed over a range of exposure doses applied to each of said prepattern shapes to target sizes, numbers and locations of inner domains of said directed self-assembly pattern.

13. The method of claim 1 , further including:

before applying said first and second tests, generating simulated photoresist profiles of said prepattern shapes and generating corresponding simulated directed self-assembly patterns using said simulated photoresist profiles: and

performing said first and second tests using said simulated directed-self assembly patterns.

14. The method of claim 13 , wherein said simulated directed self-assembly patterns are generated using a geometric heuristic algorithm.

15. The method of claim 13 , wherein a molecular dynamics simulation is used by said computer to generate said directed self-assembly patterns.

16. The method of claim 13 , wherein a look-up table of different directed self-assembly patterns of said self-assembly material and corresponding prepatterns is used by said computer to generate said directed self-assembly patterns.