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

• US 20050271953A1
• Filed: 07/26/2005
• Published: 12/08/2005
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Masktools B.V. (ASML Holding NV)
• Inventors: Broeke, Douglas Van Den, Chen, J. Fung
• Granted Patent: US 7,399,559 B2
• Time in Patent Office: Days
• US Class Current: 430/5
• CPC Class Codes: G03F 1/26 Phase shift masks [PSM]; PSM blanks; Preparation thereof
• CPC Class Codes: G03F 1/34 Phase-edge PSM, e.g. chromeless PSM; Preparation thereof
• CPC Class Codes: G03F 1/36 Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes

Abstract

A photolithography mask for optically transferring a pattern formed in the mask onto a substrate and for negating optical proximity effects. The mask includes a plurality of resolvable features to be printed on the substrate, and at least one non-resolvable optical proximity correction feature, where the non-resolvable optical proximity correction feature is a phase-edge.

Claims

1. A photolithography mask for optically transferring a pattern formed in said mask onto a substrate, said 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.

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

3. The photolithography mask of claim 1, wherein said phase-edge effects a phase-shift of 180°

.

4. The photolithography mask of claim 1, wherein said phase-edge effects a phase-shift of greater than 0°

.

7. The photolithography mask 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 photolithography mask of claim 1, wherein said mask forms a chromeless phase-shift mask.

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

12. The computer program product of claim 10, wherein said phase-edge has a width dimension substantially equal to zero.

13. The computer program product of claim 10, wherein said phase-edge effects a phase-shift of 180°

.

14. The computer program product of claim 10, wherein said phase-edge effects a phase-shift of greater than 0°

.

17. The computer program product of claim 10, wherein said mask comprises a quartz substrate, said at least one non-resolvable phase-edge being formed by etching said quartz substrate.

18. The computer program product of claim 10, wherein said mask forms a chromeless phase-shift mask.

20. The computer program product of claim 10, wherein said mask is illuminated utilizing off-axis illumination.

28. The mask 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.

30. The mask of claim 1, wherein said first resolvable feature and said second resolvable feature are densely spaced.

5. (canceled)

6. (canceled)

9. (canceled)

11. A computer program product for controlling a computer comprising a recording medium readable by the computer, means recorded on the recording medium for directing the computer to generate at least one file corresponding to a photolithography mask for optically transferring a pattern formed in said mask onto a substrate, said 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.

29. The computer program product of claim 11, 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.

31. The computer program product of claim 11, wherein said first resolvable feature and said second resolvable feature are densely spaced.

15. (canceled)

16. (canceled)

19. (canceled)

21-27. -27. (canceled)