Method, program product and apparatus for model based geometry decomposition for use in a multiple exposure process

• US 8,060,842 B2
• Filed: 12/19/2008
• Issued: 11/15/2011
• Est. Priority Date: 12/29/2005
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Masktools B.V. (ASML Holding NV)
• Inventors: Socha, Robert John
• Primary Examiner(s): Do; Thuan
• Assistant Examiner(s): Dimyan; Magid
• Application Number:
  US12/340,608
• Publication Number:
  US 20090148783A1
• Time in Patent Office: 1,061 Days
• Field of Search: 716/50, 716/55, 430/5
• US Class Current: 716/50
• CPC Class Codes: G03F 1/36 Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes
• 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 7/70433 Layout for increasing efficiency or for compensating imaging errors, e.g. layout of exposure fields for reducing focus errors; Use of mask features for increasing efficiency or for compensating imaging errors
• 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 having features to be imaged on a substrate so as to allow said features to be imaged in a multi-exposure process. The method includes the steps of: (a) segmenting a plurality of the features into a plurality of polygons; (b) determining the image log slope (ILS) value for each of the plurality of polygons; (c) determining the polygon having the minimum ILS value, and defining a mask containing the polygon; (d) convolving the mask defined in step (c) with an eigen function of a transmission cross coefficient so as to generate an interference map, where the transmission cross coefficient defines the illumination system to be utilized to image the target pattern; and (e) assigning a phase to the polygon based on the value of the interference map at a location corresponding to the polygon, where the phase defines which exposure in said multiexposure process the polygon is assigned.

Claims

1. A computer-implemented method of decomposing a target pattern having features to be imaged on a substrate so as to allow said features to be imaged in a multi-exposure process, said method comprising the steps of:

(a) segmenting, using a computer, a plurality of said features into a plurality of polygons; and

(b) assigning a phase or color to said polygons based on the value of an interference map at a location respectively corresponding to said polygons, said phase or color defining which exposure in said multi-exposure process said polygons are assigned.

2. The method of claim 1, wherein said interference map is generated by convolving a mask representing said polygons with an eigen function of a transmission cross coefficient, said transmission cross coefficient defining an illumination system.

3. The method of claim 1, wherein the method further comprises:

forming a mask containing polygons to which the same phase or color are assigned.

4. The method of claim 3, wherein the method further comprises:

exposing the mask with an exposure condition of the multi-exposure process.

5. A computer-implemented method of decomposing a target pattern having features to be imaged on a substrate so as to allow said features to be imaged in a multi-exposure process, said method comprising the steps of:

(a) segmenting, using a computer, a plurality of said features into a plurality of polygons; and

(b) assigning a phase or color to said polygons based on the result of a convolution of a mask representing said polygons with an eigen function of a transmission cross coefficient, said transmission cross coefficient defining an illumination system used in multi-exposure process.

6. The method of claim 5, wherein the method further comprises:

forming a mask containing polygons to which the same phase or color are assigned.

7. The method of claim 6, wherein the method further comprises:

exposing the mask with an exposure condition of the multi-exposure process.

8. A computer-implemented method of imaging a wafer comprising the steps of:

(c) segmenting, using a computer, a plurality of features to be imaged into a plurality of polygons; and

(d) assigning a phase or color to said polygons based on the value of an interference map at a location respectively corresponding to said polygons, said phase or color defining which exposure in a multi-exposure process said polygons are assigned.

9. The method of claim 8, wherein said interference map is generated by convolving a mask representing said polygons with an eigen function of a transmission cross coefficient, said transmission cross coefficient defining an illumination system.

10. A computer-implemented method of imaging a wafer comprising the steps of:

(e) segmenting, using a computer, a plurality of features to be imaged into a plurality of polygons; and

(f) assigning a phase or color to said polygons based on the result of a convolution of a mask representing said polygons with an eigen function of a transmission cross coefficient, said transmission cross coefficient defining an illumination system used in a multi-exposure process.

11. A computer program product for controlling a computer comprising a non-transitory recording medium readable by the computer, means recorded on the recording medium for directing the computer to decompose a target pattern having features to be imaged on a substrate so as to allow said features to be imaged in a multi-exposure process, the process comprising the steps of:

(g) segmenting a plurality of said features into a plurality of polygons; and

(h) assigning a phase or color to said polygons based on the value of an interference map at a location respectively corresponding to said polygons, said phase or color defining which exposure in said multi-exposure process said polygons are assigned.

12. The computer program product of claim 11, wherein said interference map is generated by convolving a mask representing said polygons with an eigen function of a transmission cross coefficient, said transmission cross coefficient defining an illumination system.

13. A computer program product for controlling a computer comprising a non-transitory recording medium readable by the computer, means recorded on the recording medium for directing the computer to decompose a target pattern having features to be imaged on a substrate so as to allow said features to be imaged in a multi-exposure process, the process comprising the steps of:

(i) segmenting a plurality of said features into a plurality of polygons; and

(j) assigning a phase or color to said polygons based on the result of a convolution of a mask representing said polygons with an eigen function of a transmission cross coefficient, said transmission cross coefficient defining an illumination system used in a multi-exposure process.