Method for Performing Pattern Decomposition Based on Feature Pitch

• US 20110317908A1
• Filed: 06/27/2011
• Published: 12/29/2011
• Est. Priority Date: 09/13/2006
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Masktools B.V. (ASML Holding NV)
• Inventors: Park, Jung Chul
• Granted Patent: US 8,615,126 B2
• Time in Patent Office: Days
• US Class Current: 382/145
• 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

The present invention discloses a method for decomposing a target pattern containing features to be printed on a wafer, into multiple patterns, the features having a plurality of patterns within a minimum pitch for processes utilized to image the target pattern. The method includes superposing a predefined kernel over a pixel, and moving the kernel from one pixel to another, the pixels representing the sub-patterns of the target pattern. Polarity of the kernel may be reversed when the pixel has a stored intensity value that is negative.

Claims

1-23. -23. (canceled)

24. A method for decomposing a target pattern, containing features to be printed on a wafer, into multiple patterns, the features having a plurality of patterns within a minimum pitch for processes utilized to image the target pattern, the method comprising the steps of:

(a) defining a first kernel for use in the decomposing, the kernel representing a function having a first value having a first polarity at a distance from a center equal to or less than a first distance corresponding to a maximum printable critical dimension of the features, and a second value having a second polarity which is a polarity opposite to the first polarity at a distance more than the first distance and less than a second distance corresponding to the minimum pitch;

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

(c) disposing the first kernel over a pixel of the plurality of pixels, such that the center is located on the pixel if a value stored for the pixel has the first polarity, and, disposing a second kernel in which polarity is reversed with respect to the first kernel over the pixel, such that the center is located on the pixel if the value stored for the pixel has the second polarity;

(d) determining the first value or the second value of the respective kernel at the corresponding location of each of the plurality of pixels, and storing the first value or the second value for each of the plurality of pixels;

(e) storing a value for each of the plurality of pixels by adding the previously stored pixel value to the value determined in step (d);

(f) repeating steps (c)-(e) until each of the plurality of pixels has been processed; and

(g) assigning a pattern formed by pixels of which the stored pixel value has the first polarity to a first pattern, and assigning a pattern formed by pixels of which the stored pixel value has the second polarity to a second pattern.

25. The method of claim 24, wherein the first kernel is moved sequentially from one pixel to another pixel of the plurality of pixels.

26. The method of claim 25, wherein the respective polarities of the first value and the second value of the first kernel are reversed to generate the second kernel if the value stored for the pixel over which the center of the first kernel has moved to has the second polarity.

27. The method of claim 24, wherein the first kernel comprises an annular cross section with the first value with the first polarity within an inner radius and the second value with the second polarity between the inner radius and an outer radius.

28. The method of claim 27, wherein the inner radius corresponds to the maximum printable critical dimension of the features, and the outer radius corresponds to the minimum pitch.

29. The method of claim 24 wherein an initial value of each pixel of the plurality of pixels is set to zero before disposing the first kernel.

30. A non-transitory computer-readable storage medium storing a computer program product for decomposing a target pattern, containing features to be printed on a wafer, into multiple patterns, the features having a plurality of patterns within a minimum pitch for processes utilized to image the target pattern, the computer program, when executed, causing a computer to perform the steps of:

(a) defining a first kernel for use in the decomposing, the kernel representing a function having a first value having a first polarity at a distance from a center equal to or less than a first distance corresponding to a maximum printable critical dimension of the features, and a second value having a second polarity which is a polarity opposite to the first polarity at a distance more than the first distance and less than a second distance corresponding to the minimum pitch;

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

(c) disposing the first kernel over a pixel of the plurality of pixels, such that the center is located on the pixel if a value stored for the pixel has the first polarity, and, disposing a second kernel in which polarity is reversed with respect to the first kernel over the pixel, such that the center is located on the pixel if the value stored for the pixel has the second polarity;

(d) determining the first value or the second value of the respective kernel at the corresponding location of each of the plurality of pixels, and storing the first value or the second value for each of the plurality of pixels;

(e) storing a value for each of the plurality of pixels by adding the previously stored pixel value to the value determined in step (d);

(f) repeating steps (c)-(e) until each of the plurality of pixels has been processed; and

(g) assigning a pattern formed by pixels of which the stored pixel value has the first polarity to a first pattern, and assigning a pattern formed by pixels of which the stored pixel value has the second polarity to a second pattern.

31. The computer program product of claim 30, wherein the first kernel is moved sequentially from one pixel to another pixel of the plurality of pixels.

32. The computer program product of claim 31, wherein the respective polarities of the first value and the second value of the first kernel are reversed to generate the second kernel if the value stored for the pixel over which the center of the first kernel has moved to has the second polarity.

33. The computer program product of claim 30, wherein the first kernel comprises an annular cross section with the first value with the first polarity within an inner radius and the second value with the second polarity between the inner radius and an outer radius.

34. The method of claim 33 wherein the inner radius corresponds to the maximum printable critical dimension of the features, and the outer radius corresponds to the minimum pitch.

35. The method of claim 30, wherein an initial value of each pixel of the plurality of pixels is set to zero before disposing the first kernel.

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

(a) defining a first kernel for use in the decomposing, the kernel representing a function having a first value having a first polarity at a distance from a center equal to or less than a first distance corresponding to a maximum printable critical dimension of the features, and a second value having a second polarity which is a polarity opposite to the first polarity at a distance more than the first distance and less than a second distance corresponding to the minimum pitch;

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

(c) disposing the first kernel over a pixel of the plurality of pixels, such that the center is located on the pixel if a value stored for the pixel has the first polarity, and, disposing a second kernel in which polarity is reversed with respect to the first kernel over the pixel, such that the center is located on the pixel if the value stored for the pixel has the second polarity;

(d) determining the first value or the second value of the respective kernel at the corresponding location of each of the plurality of pixels, and storing the first value or the second value for each of the plurality of pixels;

(e) storing a value for each of the plurality of pixels by adding the previously stored pixel value to the value determined in step (d);

(f) repeating steps (c)-(e) until each of the plurality of pixels has been processed;

(g) assigning a pattern formed by pixels of which the stored pixel value has the first polarity to a first pattern, and assigning a pattern formed by pixels of which the stored pixel value has the second polarity to a second pattern; and

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

37. The method of claim 36, wherein the first kernel is moved sequentially from one pixel to another pixel of the plurality of pixels.

38. The method of claim 37, wherein the respective polarities of the first value and the second value of the first kernel are reversed to generate the second kernel if the value stored for the pixel over which the center of the first kernel has moved to has the second polarity.

39. The method of claim 36, wherein the first kernel comprises an annular cross section with the first value with the first polarity within an inner radius and the second value with the second polarity between the inner radius and an outer radius.

40. The method of claim 39, wherein the inner radius corresponds to the maximum printable critical dimension of the features, and the outer radius corresponds to the minimum pitch.

41. The method of claim 36, wherein an initial value of each pixel of the plurality of pixels is set to zero before disposing the first kernel.