Method for performing pattern decomposition based on feature pitch

• US 20080144969A1
• Filed: 09/13/2007
• Published: 06/19/2008
• Est. Priority Date: 09/13/2006
• Status: Active Grant

• Current Assignee: Netcharts-Gb LLC
• Original Assignee: ASML Masktools B.V. (ASML Holding NV)
• Inventors: Park, Jung Chul
• Granted Patent: US 7,970,198 B2
• Time in Patent Office: Days
• US Class Current: 382/276
• CPC Class Codes: G03F 1/70 Adapting basic layout or design of masks to lithographic process requirements, e.g., second iteration correction of mask patterns for imaging

Abstract

A method for decomposing a target pattern containing features to be printed on a wafer. The method includes the steps of: (a) defining a kernel representing a function having positive values within an inner radius and negative values in an outer radius; (b) defining the features utilizing a plurality of pixels; (c) disposing the kernel over a first pixel of the plurality of pixels; (d) determining the value of the kernel at location of each of the plurality of pixels, storing the value for each of the plurality of pixels so as to define a pixel value for each of the plurality of pixels; (e) adding a previously stored value associated with a given pixel of the plurality of pixels with the pixel value of the given pixel determined in step (d); (f) disposing the kernel over another pixel of the plurality of pixels, and repeating steps (d)-(f) until each of the plurality of pixels has been processed; and (g) determining placement of the pixel in a first pattern or a second pattern based on the pixel value of the given pixel.

Claims

1. A method for decomposing a target pattern containing features to be printed on a wafer, into multiple patterns, comprising the steps of:

(a) defining a kernel representing a function having positive values within an inner radius and negative values in an outer radius;

(b) defining said features utilizing a plurality of pixels;

(c) disposing said kernel over a first pixel of said plurality of pixels;

(d) determining the value of the kernel at location of each of said plurality of pixels, storing said value for each of said plurality of pixels so as to define a pixel value for each of said plurality of pixels;

(e) adding a previously stored value associated with a given pixel of said plurality of pixels with said pixel value of the given pixel determined in step (d);

(f) disposing said kernel over another pixel of said plurality of pixels, and repeating steps (d)-(f) until each of said plurality of pixels has been processed; and

(g) determining placement of said pixel in a first pattern or a second pattern based on the pixel value of the given pixel.

2. A method for decomposing a target pattern containing features to be printed on a wafer according to claim 1, wherein said outer radius corresponds to a pitch value which is less than a minimum pitch for a process to be utilized to image said multiple patterns.

3. A method for decomposing a target pattern containing features to be printed on a wafer according to claim 1, wherein when disposing said kernel over a given pixel, the center of the kernel is disposed over said given pixel.

4. A method for decomposing a target pattern containing features to be printed on a wafer according to claim 1, wherein the value associated with each of said plurality of pixels is initially assigned to zero.

5. A method for decomposing a target pattern containing features to be printed on a wafer according to claim 1, wherein said pixels having a positive value are assigned to said first pattern, and pixels having a negative value are assigned to said second pattern.

6. A method for decomposing a target pattern containing features to be printed on a wafer according to claim 1, wherein a given feature may be segmented into multiple portions, with a first portion of said segmented feature being assigned to said first pattern and a second portion of said segmented feature being assigned to said second pattern.

7. A computer readable storage medium storing a computer program for decomposing a target pattern containing features to be printed on a wafer, into multiple patterns, when executed, causing a computer to perform the steps of:

(a) defining a kernel representing a function having positive values within an inner radius and negative values in an outer radius;

(b) defining said features utilizing a plurality of pixels;

(c) disposing said kernel over a first pixel of said plurality of pixels;

(d) determining the value of the kernel at location of each of said plurality of pixels, storing said value for each of said plurality of pixels so as to define a pixel value for each of said plurality of pixels;

(e) adding a previously stored value associated with a given pixel of said plurality of pixels with said pixel value of the given pixel determined in step (d);

(f) disposing said kernel over another pixel of said plurality of pixels, and repeating steps (d)-(f) until each of said plurality of pixels has been processed; and

(g) determining placement of said pixel in a first pattern or a second pattern based on the pixel value of the given pixel.

8. A computer readable storage medium according to claim 7, wherein said outer radius corresponds to a pitch value which is less than a minimum pitch for a process to be utilized to image said multiple patterns.

9. A computer readable storage medium according to claim 7, wherein when disposing said kernel over a given pixel, the center of the kernel is disposed over said given pixel.

10. A computer readable storage medium according to claim 7, wherein the value associated with each of said plurality of pixels is initially assigned to zero.

11. A computer readable storage medium according to claim 7, wherein said pixels having a positive value are assigned to said first pattern, and pixels having a negative value are assigned to said second pattern.

12. A computer readable storage medium according to claim 7, wherein a given feature may be segmented into multiple portions, with a first portion of said segmented feature being assigned to said first pattern and a second portion of said segmented feature being assigned to said second pattern.

13. A device manufacturing method comprising the steps of:

(a) defining a kernel representing a function having positive values within an inner radius and negative values in an outer radius;

(b) defining said features utilizing a plurality of pixels;

(c) disposing said kernel over a first pixel of said plurality of pixels;

(d) determining the value of the kernel at location of each of said plurality of pixels, storing said value for each of said plurality of pixels so as to define a pixel value for each of said plurality of pixels;

(e) adding a previously stored value associated with a given pixel of said plurality of pixels with said pixel value of the given pixel determined in step (d);

(f) disposing said kernel over another pixel of said plurality of pixels, and repeating steps (d)-(f) until each of said plurality of pixels has been processed; and

(g) determining placement of said pixel in a first pattern or a second pattern based on the pixel value of the given pixel.

14. A device manufacturing method according to claim 13, wherein said outer radius corresponds to a pitch value which is less than a minimum pitch for a process to be utilized to image said multiple patterns.

15. A device manufacturing method according to claim 13, wherein when disposing said kernel over a given pixel, the center of the kernel is disposed over said given pixel.

16. A device manufacturing method according to claim 13, wherein the value associated with each of said plurality of pixels is initially assigned to zero.

17. A device manufacturing method according to claim 13, wherein said pixels having a positive value are assigned to said first pattern, and pixels having a negative value are assigned to said second pattern.

18. A device manufacturing method according to claim 13, wherein a given feature may be segmented into multiple portions, with a first portion of said segmented feature being assigned to said first pattern and a second portion of said segmented feature being assigned to said second pattern.

19. A method for generating masks to be utilized in a photolithography process, said method comprising the steps of:

(a) defining a kernel representing a function having positive values within an inner radius and negative values in an outer radius;

(b) defining said features utilizing a plurality of pixels;

(c) disposing said kernel over a first pixel of said plurality of pixels;

(d) determining the value of the kernel at location of each of said plurality of pixels, storing said value for each of said plurality of pixels so as to define a pixel value for each of said plurality of pixels;

(e) adding a previously stored value associated with a given pixel of said plurality of pixels with said pixel value of the given pixel determined in step (d);

(f) disposing said kernel over another pixel of said plurality of pixels, and repeating steps (d)-(f) until each of said plurality of pixels has been processed;

(g) determining placement of said pixel in a first pattern or a second pattern based on the pixel value of the given pixel; and

(h) generating a first mask corresponding to said first pattern, and a second mask corresponding to said second pattern.

20. A method for generating masks according to claim 19, wherein said outer radius corresponds to a pitch value which is less than a minimum pitch for a process to be utilized to image said multiple patterns.

21. A method for generating masks according to claim 19, wherein when disposing said kernel over a given pixel, the center of the kernel is disposed over said given pixel.

22. A method for generating masks according to claim 19, wherein the value associated with each of said plurality of pixels is initially assigned to zero.

23. A method for generating masks according to claim 19, wherein said pixels having a positive value are assigned to said first pattern, and pixels having a negative value are assigned to said second pattern.