Optical proximity correction method utilizing phase-edges as sub-resolution assist features

1. A method of transferring a lithographic pattern from a photography mask onto a substrate by use of a lithographic exposure apparatus, said method comprising the steps of:

forming a plurality of resolvable features to be printed on said substrate; and

forming at least one non-resolvable optical proximity correction feature, said at least one non-resolvable optical proximity correction feature being a phase-edge,

wherein said at least one non-resolvable phase-edge is the sole optical proximity correction feature positioned between a first resolvable feature and a second resolvable feature.

2. The method of claim 1 , wherein said phase-edge has a width dimension substantially equal to zero.

3. The method of claim 1 , wherein said phase-edge effects a phase-shift of greater than 0°.

4. The method of claim 1 , wherein said phase-edge effects a phase-shift of 180°.

5. The method of claim 1 , wherein said mask is illuminated utilizing off-axis illumination.

6. A device manufacturing method comprising the steps of:

(a) providing a substrate that is at least partially covered by a layer of radiation-sensitive material;

(b) providing a projection beam of radiation using a radiation system;

(c) using a pattern on a mask to endow the projection beam with a pattern in its cross-section;

(d) projecting the patterned beam of radiation onto a target portion of the layer of radiation-sensitive material,

wherein, in step (c), use is made of a mask comprising:

a plurality of resolvable features to be printed on said substrate; and

at least one non-resolvable optical proximity correction feature, said at least one non-resolvable optical proximity correction feature being a phase-edge;

wherein said at least one non-resolvable phase-edge is the sole optical proximity correction feature positioned between a first resolvable feature and a second resolvable feature.

7. The method of claim 1 , wherein said mask comprises a quartz substrate, said at least one non-resolvable phase-edge being formed by etching said quartz substrate.

8. The method of claim 1 , wherein said mask forms a chromeless phase-shift mask.

9. The method of claim 1 , wherein said non-resolvable feature is spaced apart from said given one of said resolvable features so as to maximize the depth of focus of an imaging system for a given feature size.

10. The method of claim 1 , wherein the phase-shift effected by said phase-edge is selected so as to maintain said phase-edge sub-resolution.

11. The device manufacturing method of claim 6 , wherein said phase-edge has a width dimension substantially equal to zero.

12. The device manufacturing method of claim 6 , wherein said phase-edge effects a phase-shift of greater than 0°.

13. The device manufacturing method of claim 6 , wherein said phase-edge effects a phase-shift of 180°.

14. The device manufacturing method of claim 6 , wherein said mask forms a chromeless phase-shift mask.

15. The device manufacturing method of claim 6 , wherein said non-resolvable feature is spaced apart from said given one of said resolvable features so as to maximize the depth of focus of an imaging system for a given feature size.

16. The device manufacturing method of claim 6 , wherein the phase-shift effected by said phase-edge is selected so as to maintain said phase-edge sub-resolution.

17. The device manufacturing method of claim 6 , wherein said mask is illuminated utilizing off-axis illumination.

18. The device manufacturing method of claim 6 , wherein said mask comprises a quartz substrate, said at least one non-resolvable phase-edge being formed by etching said quartz substrate.