SCATTERING BAR OPC APPLICATION METHOD FOR SUB-HALF WAVELENGTH LITHOGRAPHY PATTERNING FIELD OF THE INVENTION

• US 20090233186A1
• Filed: 01/08/2009
• Published: 09/17/2009
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: Donglas Van Den Broeke, Jang Fung Chen, Kurt Wampler, Thomas Laidig
• Inventors: Broeke, Donglas Van Den, Laidig, Thomas, Chen, Jang Fung, Wampler, Kurt E.
• Granted Patent: US 7,892,707 B2
• Time in Patent Office: Days
• US Class Current: 430/5
• CPC Class Codes: G03F 1/36 Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes

Abstract

A method of forming a mask having optical proximity correction features, which includes the steps of obtaining a target pattern of features to be imaged, expanding—the width of the features to be imaged, modifying the mask to include assist features which are placed adjacent the edges of the features to be imaged, where the assist features have a length corresponding to the expanded width of the features to be imaged, and returning the features to be imaged from the expanded width to a width corresponding to the target pattern.

Claims

1. A method of forming a mask containing a target pattern comprising features to be imaged, said method comprising the steps of:

(a) obtaining said target pattern comprising features to be imaged;

(b) expanding the width of said features to be imaged;

(c) modifying said mask to include assist features, said assist features being placed adjacent edges of said features to be imaged, said assist features having a length corresponding to the expanded width of said features to. be imaged; and

(d) reducing the features to be imaged from the expanded width to a width corresponding to the target pattern;

wherein said mask includes said assist features and said features to be imaged, said features to be imaged having said width corresponding to said target pattern.

2. The method of forming a mask according to claim 1, wherein step (b) and step (c) further comprise the steps of

expanding the width of said features to be imaged in a first direction by a predetermined amount;

modifying said mask to include horizontally aligned assist features which are disposed adjacent horizontal edges formed by said expanded features in a first direction;

expanding the width of said features to be imaged in a. second direction by a predetermined amount; and

modifying said mask to include vertically aligned assist features which are disposed adjacent vertical edges formed by said expanded features in a second direction, said first direction and said second direction being orthogonal to one another.

3. The method of forming a mask according to claim 2, further comprising the step of canceling any portion of said horizontally aligned assist features that overlap with said vertically aligned assist features from said mask, and canceling any portion of said vertically aligned assist features that overlap with said horizontally aligned assist features from said mask.

4. The method of forming a mask according to claim 1, wherein said assist features are subresolution such that said assist features do not print when said mask is imaged.

5. The method of forming a mask according to claim 2, wherein a single, continuous vertically aligned assist feature is disposed proximate line ends of horizontally aligned features that are disposed adjacent one another.

6. The method of forming a mask according to claim 2, wherein a single, continuous horizontally aligned assist feature is disposed proximate line ends of vertically aligned features that are disposed adjacent one another.

7. A method of forming a mask comprising features to be imaged and optical proximity correction features;

said method comprising the steps of;

forming a first assist feature extending in a first direction;

forming a second assist feature extending in a second direction, said first direction and said second direction being orthogonal to one another; and

forming a chamfer assist feature which connects said first assist feature to said second assist feature, said chamfer assist feature disposed at an angle relative to both said first assist feature and said second assist feature.

8. The method of forming a mask according to- claim 7, wherein said chamfer assist feature has a primary axis which is disposed at approximately a 45°

angle relative to a primary axis of said first assist feature, and a primary axis of said second assist feature.

9. The method of forming a mask according to claim 7, wherein said chamfer assist feature has a triangular configuration.

10. The method of forming a mask according to claim 9, wherein said chamfer-assist feature has a configuration forming a right-triangle having approximately angles of 45°

, 45° and

900.

11. The method of forming a mask according to claim 7, wherein said chamfer assist feature has a trapezoidal configuration.

12. A method of forming a mask comprising features to be imaged and optical proximity correction features;

said method comprising the steps of forming a plurality of first assist features, each of which extends in a first direction;

forming a plurality of second assist features, each of which extends in a second direction, said first direction and said second direction being orthogonal to one another; and

forming a plurality of chamfer assist features, each of which connects one of said first assist features to one of said plurality of second assist features, each of said chamfer assist features disposed at an angle relative to both said plurality of first assist features and said plurality of second assist features.

13. The method of forming a mask according to claim 12, wherein at least a portion of said plurality of first assist features, at least a portion of said plurality of second assist features, and at least a portion of said chamfer assist features are arranged so as to substantially surround a feature to be imaged.

14. The method of forming a mask according to claim 12, wherein each of said plurality of chamfer assist features has a primary axis which is disposed at approximately a 45°

angle relative to a primary axis of each of said plurality of first assist features, and a primary axis of each of said plurality of second assist features.

15. The method of forming a mask according to claim 12, wherein each of said plurality of chamfer assist features have at least of one a triangular configuration or a trapezoidal configuration.

16. A program product, comprising executable code transportable by at least one machine readable medium, wherein execution of the code by at least one programmable computer causes the at least one programmable computer to perform a sequence of steps for forming a mask for optically transferring a pattern formed in said mask onto a substrate, said steps comprising:

(a) obtaining a target pattern comprising features to be imaged;

(b) expanding the width of said features to be imaged;

(c) modifying said mask to include assist features, said assist features being placed adjacent edges of said features to be imaged, said assist features having a length corresponding to the expanded width of said features to be imaged; and

(d) reducing the features to be imaged from the expanded width to a width corresponding to the target pattern;

wherein said mask includes said assist features and said features to be imaged, said features to be imaged having said width corresponding to said target pattern.

17. The program product according to claim 16, wherein step (b) and step (c) further comprise the steps of:

expanding the width of said features to be imaged in a first direction by a predetermined amount;

modifying said mask to include horizontally aligned assist features which are disposed adjacent horizontal edges formed by said expanded features in a first direction;

expanding the width of said features to be imaged in a second direction by a predetermined amount; and

modifying said mask to include vertically aligned assist features which are disposed adjacent vertical edges formed by said expanded features in a second direction, said first direction and said second direction being orthogonal to one another.

18. The program product according to claim 17, further comprising the step of canceling any portion of said horizontally aligned assist features that overlap with said vertically aligned assist features from said mask, and canceling any portion of said vertically aligned assist features that overlap with said horizontally aligned assist features from said mask.

19. The program product according to claim 16, wherein said assist features are subresolution such that said assist features do not print when said mask is imaged.

20. The program product according to claim 17, wherein a single, continuous vertically aligned assist feature is disposed proximate line ends of horizontally aligned features that are disposed adjacent one another.

21. The program product according to claim 17, wherein a single, continuous horizontally aligned assist feature is disposed proximate line ends of vertically aligned features that are disposed adjacent one another.

22. A program product, comprising executable code transportable by at least one machine readable medium, wherein execution of the code by at least one programmable computer causes the at least one programmable computer to perform a sequence of steps for forming a mask for optically transferring a pattern formed in said mask onto a substrate, said steps comprising:

forming a first assist feature extending in a first direction;

forming a second assist feature extending in a second direction, said first direction and said second direction being orthogonal to one another; and

forming a chamfer assist feature which connects said first assist feature to said second assist feature, said chamfer assist feature disposed at an angle relative to both said first assist feature and said second assist feature.

23. A program product according to claim 22, wherein said chamfer assist feature has a primary axis which is disposed at approximately a 45°

angle relative to a primary axis of said first assist feature, and a primary axis of said second assist feature.

24. A program product according to claim 22, wherein said chamfer assist feature has a triangular configuration.

25. A program product according to claim 23, wherein said chamfer assist feature has a configuration forming a right-triangle having approximately angles of 45°

, 45° and

90°

.

26. A program product according to claim 24, wherein said chamfer assist feature has a trapezoidal configuration.

27. A program product, comprising executable code transportable by at least one machine readable medium, wherein execution of the code by at least one programmable computer causes the at least one programmable computer to perform a sequence of steps for forming a mask for optically transferring a pattern formed in said mask onto a substrate, said steps comprising:

forming a plurality of first assist features, each of which extends in a first direction;

forming a plurality of second assist features, each of which extends in a second direction, said first direction and said second direction being orthogonal to one another; and

forming a plurality of chamfer assist features, each of which connects one of said first assist features to one of said plurality of second assist features, each of said chamfer assist features disposed at an angle relative to both said plurality of first assist features and said plurality of second assist features, wherein at least a portion of said plurality of first assist features, at least a portion of said plurality of second assist features, and at least a portion of said chamfer assist features are arranged so as to substantially surround a feature to be imaged.

28. A method of forming a mask comprising features to be imaged and optical proximity correction features;

said method comprising the steps of;

forming a first assist feature extending in a first direction;

forming a second assist feature extending in a direction parallel to said first direction;

forming a chamfer assist feature which connects said first assist feature to said second assist feature, said chamfer assist feature disposed at an angle relative to both said first assist feature and said second assist feature.

29. The method of forming a mask according to claim 28, wherein said chamfer assist feature has a primary axis which is disposed at approximately a 45°

angle relative to a primary axis of said first assist feature, and a primary axis of said second assist feature.

30. The method of forming a mask according to claim 28, wherein said chamfer assist feature has a parallelogram configuration.