Method, program product and apparatus for performing decomposition of a pattern for use in a DPT process

• US 8,495,526 B2
• Filed: 01/03/2011
• Issued: 07/23/2013
• Est. Priority Date: 11/14/2006
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Masktools B.V. (ASML Holding NV)
• Inventors: Socha, Robert J.
• Primary Examiner(s): Whitmore, Stacy
• Application Number:
  US12/983,858
• Publication Number:
  US 20110097653A1
• Time in Patent Office: 932 Days
• Field of Search: 716 50- 56
• US Class Current: 716/53
• CPC Class Codes: G03F 1/26 Phase shift masks [PSM]; PSM blanks; Preparation thereof
• CPC Class Codes: G03F 1/68 Preparation processes not covered by groups G03F1/20 - G03F1/50
• 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
• CPC Class Codes: G03F 7/70466 Multiple exposures, e.g. combination of fine and coarse exposures, double patterning or multiple exposures for printing a single feature stitching G03F7/70475
• CPC Class Codes: G03F 7/705 Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions

Abstract

A method of decomposing a target pattern containing features to be printed on a wafer into multiple patterns. The method includes the steps of: (a) defining a region of influence which indicates the minimum necessary space between features to be imaged; (b) selecting a vertex associated with a feature of the target pattern; (c) determining if an edge of another feature is within the region of influence with respect to the vertex; and (d) splitting the another feature into two polygons if the edge of another feature is within the region of influence.

Claims

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

(a) defining a region of influence which indicates the minimum necessary space between features to be imaged;

(b) selecting a vertex associated with a feature of said target pattern,

(c) determining, by the computer, if an edge of another feature is within said region of influence with respect to said vertex, and placing a new vertex created by applying a fragmentation process, if said edge of said another feature is within said region of influence; and

(d) splitting said another feature into two polygons, whose common edge includes said new vertex created by applying said fragmentation process, for separate inclusion into different ones of said multiple patterns when it is determined that said edge of another feature is within said region of influence.

2. The method of claim 1, further comprising the step of repeating steps (b)-(d) such that each vertex of each feature of said target pattern is analyzed.

3. The method of claim 1, wherein said region of influence is defined by the formula k₁λ

/NA, where k₁ is the minimum k₁ to print features in a single exposure, λ

is the wavelength associated with the illumination source, and NA is the numerical aperture.

4. The method of claim 1, wherein said region of influence is determined by at least one of a simulation process or actual experimental imaging data.

5. The method of claim 1, wherein step (c) comprises the steps of:

extending a segment from said vertex until said segment intersects at least one of an edge or vertex of one of said features; and

extending a ray from a middle portion of said segment by a length equal to said region of influence.

17. A mask generated utilizing the method of claim 1.

6. A non-transitory computer readable medium bearing a computer program for decomposing a target pattern containing features to be printed on a wafer, into multiple patterns to be imaged separately, the computer program, when executed, causing a computer to perform the steps of:

(a) defining a region of influence which indicates the minimum necessary space between features to be imaged;

(b) selecting a vertex associated with a feature of said target pattern,

(c) determining if an edge of another feature is within said region of influence with respect to said vertex, and placing a new vertex created by applying a fragmentation process, if said edge of said another feature is within said region of influence; and

(d) splitting said another feature into two polygons, whose common edge includes said new vertex created by applying said fragmentation process, for separate inclusion into different ones of said multiple patterns when it is determined that said edge of another feature is within said region of influence.

7. The computer readable medium of claim 6, further comprising the step of repeating steps (b)-(d) such that each vertex of each feature of said target pattern is analyzed.

8. The computer readable medium of claim 6, wherein said region of influence is defined by the formula k₁λ

/NA, where k₁ is the minimum k₁ to print features in a single exposure, λ

is the wavelength associated with the illumination source, and NA is the numerical aperture.

9. The computer readable medium of claim 6, wherein said region of influence is determined by at least one of a simulation process or actual experimental imaging data.

10. The computer readable medium of claim 6, wherein step (c) comprises the steps of:

extending a segment from said vertex until said segment intersects at least one of an edge or vertex of one of said features; and

extending a ray from a middle portion of said segment by a length equal to said region of influence.

11. 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 an imaging system;

(c) using a target 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), said mask is formed by a method comprising the steps of;

(e) defining a region of influence which indicates a minimum necessary space between features of said target pattern to be imaged;

(f) selecting a vertex associated with a feature of said target pattern,

(g) determining if an edge of another feature is within said region of influence with respect to said vertex, and placing a new vertex created by applying a fragmentation process, if said edge of said another feature is within said region of influence; and

(h) splitting said another feature into two polygons, whose common edge includes said new vertex created by applying said fragmentation process, for separate inclusion into different ones of said multiple patterns to be imaged separately when it is determined that said edge of another feature is within said region of influence.

12. A computer-implemented method for generating masks to be imaged separately in a photolithography process, said method comprising the steps of:

(a) defining a region of influence which indicates a minimum necessary space between features of a target pattern to be imaged;

(b) selecting a vertex associated with a feature of said target pattern,

(c) determining, by the computer, if an edge of another feature is within said region of influence with respect to said vertex, and placing a new vertex created by applying a fragmentation process, if said edge of said another feature is within said region of influence; and

(d) splitting said feature into two polygons, whose common edge includes said new vertex created by applying said fragmentation process, for separate inclusion into different ones of said multiple patterns when it is determined that said edge of another feature is within said region of influence.

13. The method of claim 12, further comprising the step of repeating steps (b)-(d) such that each vertex of each feature of said target pattern is analyzed.

14. The method of claim 12, wherein said region of influence is defined by the formula k₁/λ

NA, where k₁ is the minimum k₁ to print features in a single exposure, λ

is the wavelength associated with the illumination source, and NA is the numerical aperture.

15. The method of claim 12, wherein said region of influence is determined by at least one of a simulation process or actual experimental imaging data.

16. The method of claim 12, wherein step (c) comprises the steps of:

extending a segment from said vertex until said segment intersects at least one of an edge or vertex of one of said features; and

extending a ray from a middle portion of said segment by a length equal to said region of influence.

18. A mask generated utilizing the method of claim 12.