Metal fill optimization for self-aligned double patterning

1. A method of optimizing self-aligned double patterning, the method comprising:

providing predefined locations for required metal cuts in order to form metal wires from metal fills that have been cut, the metal wires having a priority;

providing extended locations for extended metal cuts in order to cut adjacent metal fills, the adjacent metal fills being the metal fills that are adjacent to the predefined locations for the required metal cuts, wherein the extended metal cuts extend beyond the required metal cuts, wherein the metal wires having a higher priority are associated with a higher likelihood of having the extended metal cuts as compared to the metal wires having a lower priority; and

performing the required metal cuts into the metal fills and the extended metal cuts into the adjacent metal fills.

2. The method of claim 1 , further comprising performing a check to determine if the extended locations for the extended metal cuts violate design rules.

3. The method of claim 2 , further comprising removing the extended locations for the extended metal cuts that violate the design rules.

4. The method of claim 2 , further comprising for a given extended location for a given extended metal cut that violates a minimum spacing requirement of the design rules with respect to a given cut, utilizing a first mask to make the given extended metal cut and a second mask to make the given cut, thereby avoiding the minimum spacing requirement.

5. The method of claim 1 , wherein the required metal cuts into the metal fills and the extended metal cuts into the adjacent metal fills are both performed simultaneously.

6. The method of claim 1 , wherein the extended metal cuts into the adjacent metal fills reduce parasitic capacitance.

7. The method of claim 1 , wherein the adjacent metal fills are adjacent to the metal wires having been formed by the required metal cuts at the predefined locations.

8. The method of claim 7 , wherein a given adjacent metal fill for a given metal wire is not on a same row as the given metal wire.

9. The method of claim 1 , wherein a given predefined location is in a first row, the given predefined location being for a given required metal cut to form a given metal wire from a given metal fill.

10. The method of claim 9 , wherein a given extended location is in a second row, the given extended location being for a given extended metal cut to cut a given adjacent metal fill.

11. The method of claim 10 , wherein the given extended location for the given extended metal cut is aligned to the given predefined location for the given required metal cut, such that the given extended metal cut is aligned to the given required metal cut.

12. The method of claim 1 , further comprising performing an additional cut on the adjacent metal fills having a length greater than a predefined length, in order to reduce parasitic capacitance affecting the metal wires adjacent to the adjacent metal fills.

13. A structure formed by self-aligned double patterning, the structure comprising:

wire metals formed by cutting metal fills to form required metal cuts, the metal wires having a priority; and

adjacent metal fills of the metal fills, the adjacent metal fills including extended cuts, wherein the extended cuts are aligned to the required metal cuts, wherein the required metal cuts and the extended cuts are spaces of removed metal from the metal fills, wherein the metal wires having a higher priority are associated with a higher likelihood of having the extended metal cuts as compared to the metal wires having a lower priority.

14. The structure of claim 13 , wherein the spaces of the extended cuts in the adjacent metal fills and the spaces of the required metal cuts in the metal fills are aligned in a horizontal direction.

15. The structure of claim 14 , wherein the spaces of the extended cuts and the required metal cuts have an equal length.

16. The structure of claim 14 , wherein the adjacent metal fills are the metal fills that are adjacent to predefined locations for the required metal cuts, wherein the extended cuts extend an offset distance beyond the required metal cuts.

17. The structure of claim 14 , wherein the wire metal includes copper.

18. The structure of claim 14 , wherein the wire metal includes aluminum.

19. The structure of claim 14 , wherein the wire metal includes gold.

20. A computer program product of a design for optimizing self-aligned double patterning, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions readable by a computer to cause the computer to perform a method comprising:

providing predefined locations for required metal cuts in order to form metal wires from metal fills that have been cut, the metal wires having a priority;

providing extended locations for extended metal cuts in order to cut adjacent metal fills, the adjacent metal fills being the metal fills that are adjacent to the predefined locations for the required metal cuts, wherein the extended metal cuts extend beyond the required metal cuts, wherein the metal wires having a higher priority are associated with a higher likelihood of having the extended metal cuts as compared to the metal wires having a lower priority; and

causing fabrication equipment to perform the required metal cuts into the metal fills and the extended metal cuts into the adjacent metal fills.