Contrast based resolution enhancement for photolithographic processing

1. A method of processing a data layout file defining a plurality of features to be created in an integrated device, comprising:

receiving at least a portion of a data layout file that defines a number of features to be created in an integrated device;

fragmenting each of the features received into a number of edge fragments;

estimating a contrast value for each of the edge fragments;

determining an original distribution of contrast values for the edge fragments;

selecting a threshold contrast value;

selecting at least one resolution enhancement parameter for application to one or more of the edge fragments;

determining new distributions of contrast values for values of the selected resolution enhancement parameter applied to the one or more edge fragments in the data layout file;

comparing the new distributions of contrast values with the original distribution of contrast values; and

creating a revised version of the portion of the data layout file using a value of the selected resolution enhancement parameter that produces a distribution with more edge fragments having contrast values that are higher than the threshold contrast value than were present in the original distribution.

2. The method of claim 1 , in which the one or more edge fragments to which the resolution enhancement parameter is applied have similar initial contrast values.

3. The method of claim 1 , in which the integrated device is an integrated circuit.

4. The method of claim 1 , further comprising:

determining if the value of the resolution enhancement parameter applied to the one or more edge fragments in the layout causes individual edge fragments to have a lower contrast value than the initial contrast value, and if so, adjusting the value of the resolution enhancement parameter applied to the individual edge fragments.

5. The method of claim 1 , wherein the at least one resolution enhancement parameter includes the size of a sub-resolution assist feature positioned adjacent each edge fragment.

6. The method of claim 1 , wherein the at least one resolution enhancement parameter includes the distance between a sub-resolution assist feature and a neighboring edge fragment.

7. The method of claim 1 , wherein the at least one resolution enhancement parameter includes the width of a sub-resolution assist feature and a neighboring edge fragment.

8. The method of claim 1 , wherein the at least one resolution enhancement parameter includes the width of a phase shifted window neighboring an edge fragment.

9. The method of claim 1 , wherein the at least one resolution enhancement parameter includes the spacing or separation between subresolution assist features neighboring an edge fragment.

10. The method of claim 1 , wherein the at least one resolution enhancement parameter includes an extension, serif or hammerhead neighboring an edge fragment.

11. The method of claim 1 , wherein the at least one resolution enhancement parameter includes the positive or negative bias associated with an edge fragment for each of a single or multiple exposure.

12. The method of claim 1 , wherein the at least one resolution enhancement parameter includes the phase of a feature that abuts a neighboring edge fragment.

13. The method of claim 1 , wherein the at least one resolution enhancement parameter includes a transmission of a feature that abuts to a neighboring edge fragment.

14. The method of claim 1 , wherein the at least one resolution enhancement parameter includes a local light polarization modifier around a neighboring edge fragment.

15. The method of claim 1 , wherein the at least one resolution enhancement parameter includes a bias value of a dipole illumination device.

16. The method of claim 1 , further comprising:

supplying the edge fragments and the applied resolution enhancement parameters to an OPC system to selectively bias the position of the edge fragments.

17. The method of claim 16 , wherein the OPC system is a rule-based system.

18. The method of claim 16 , wherein the OPC system is a model-based system.

19. The method of claim 1 , wherein the value of the resolution enhancement parameter applied to the one or more edge fragments is determined by:

selecting a value of the resolution enhancement parameter that maximizes the number of edge fragments that have a contrast value that is greater than or equal to the threshold contrast value.

20. The method of claim 1 , further comprising applying a weighting function to the distribution of contrast values determined after a value of the resolution enhancement parameter is applied.

21. The method of claim 1 , further comprising applying the values of the one or more resolution enhancement parameters to edge fragments in another data layout file.

22. A computer readable media including a sequence of programmed instructions that cause a computer system to implement any of the method claims 1 - 19 .

23. A data layout file describing a number of features to be created in an integrated device that has been processed according to any of the method claims 1 - 19 .