Optimization of source and bandwidth for new and existing patterning devices

Patent metadata

Field	Value
Publication number	US-10416566-B2
Application number	US-201615781970-A
Country	US
Kind code	B2
Filing date	Nov 30, 2016
Priority date	Dec 14, 2015
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

A method to improve a lithographic process of imaging a portion of a design layout onto a substrate using a lithographic apparatus, the method including: computing a multi-variable cost function, the multi-variable cost function being a function a plurality of design variables that represent characteristics of the lithographic process; and reconfiguring one or more of the characteristics of the lithographic process by adjusting one or more of the design variables until a certain termination condition is satisfied; wherein a bandwidth of a radiation source of the lithographic apparatus is allowed to change during the reconfiguration.

First claim

What is claimed is:

1. A method to improve a lithographic process of imaging a portion of a design layout onto a substrate using a lithographic apparatus, the method comprising:
computing, by a hardware computer system, a multi-variable cost function of a plurality of design variables that represent characteristics of the lithographic process, the multi-variable cost function being a function of a bandwidth of a radiation source of the lithographic apparatus, or being a function of a variable that is a function of the bandwidth or that affects the bandwidth; and
reconfiguring, by the hardware computer system, one or more of the characteristics of the lithographic process by adjusting one or more of the design variables and re-computing the multi-variable cost function based on the adjusted one or more design variables until a certain termination condition is satisfied.

2. The method of claim 1 , wherein the reconfiguration is under a constraint that any geometrical characteristics of a patterning device comprising the design layout are not allowed to change.

3. The method of claim 1 , wherein the bandwidth is a full width at half maximum (FWHM) bandwidth, or wherein the bandwidth is an E95 bandwidth.

4. The method of claim 1 , wherein reconfiguring the one or more of the characteristics of the lithographic process improves an image quality of the portion of the design layout.

5. The method of claim 1 , wherein reconfiguring the one or more of the characteristics of the lithographic process increases latitude of at least one of the design variables.

6. The method of claim 5 , wherein the latitude is depth of focus or exposure latitude.

7. The method of claim 1 , wherein the cost function evaluates one or more selected from the following: edge placement error, critical dimension, a resist contour characteristic, worst defect size, exposure latitude, image shift, mask error enhancement factor or focus.

8. A computer program product comprising a non-transitory computer-readable medium having instructions recorded thereon, the instructions, when executed by a computer system, configured to cause at least:
computation of a multi-variable cost function of a plurality of design variables that represent characteristics of a lithographic process of imaging a portion of a design layout onto a substrate using the lithographic apparatus, the multi-variable cost function being a function of a bandwidth of a radiation source of a lithographic apparatus, or being a function of a variable that is a function of the bandwidth or that affects the bandwidth; and
reconfiguration of one or more of the characteristics of the lithographic process by adjusting one or more of the design variables and re-computing the multi-variable cost function based on the adjusted one or more design variables until a certain termination condition is satisfied.

9. A computer program product comprising a non-transitory computer-readable medium having instructions recorded thereon, the instructions, when executed by a computer system, configured to cause at least:
computation of a multi-variable cost function, the multi-variable cost function being a function of a plurality of design variables that represent characteristics of a lithographic process of imaging a portion of a design layout onto a substrate using a lithographic apparatus; and
reconfiguration of one or more of the characteristics of the lithographic process by adjusting one or more of the design variables and re-computing the multi-variable cost function based on the adjusted one or more design variables until a certain termination condition is satisfied,
wherein a bandwidth of a radiation source of the lithographic apparatus is allowed to change during the reconfiguration.

10. The computer program product of claim 9 , wherein the reconfiguration is under a constraint that any geometrical characteristics of a patterning device comprising the design layout are not allowed to change.

11. A method to improve a lithographic process of imaging a portion of a design layout onto a substrate using a lithographic apparatus, the method comprising:
computing, by a hardware computer system, a multi-variable cost function, the multi-variable cost function being a function of a plurality of design variables that represent characteristics of the lithographic process; and
reconfiguring, by the hardware computer system, one or more of the characteristics of the lithographic process by adjusting one or more of the design variables and re-computing the multi-variable cost function based on the adjusted one or more design variables until a certain termination condition is satisfied,
wherein a bandwidth of a radiation source of the lithographic apparatus is allowed to change during the reconfiguration.

12. The method of claim 11 , wherein the reconfiguration is under a constraint that any geometrical characteristics of a patterning device comprising the design layout are not allowed to change.

13. The method of claim 11 , wherein the bandwidth is a full width at half maximum (FWHM) bandwidth, or wherein the bandwidth is an E95 bandwidth.

14. The computer program product of claim 8 , wherein the reconfiguration is under a constraint that any geometrical characteristics of a patterning device comprising the design layout are not allowed to change.

15. The computer program product of claim 8 , wherein the bandwidth is a full width at half maximum (FWHM) bandwidth, or wherein the bandwidth is an E95 bandwidth.

16. The computer program product of claim 8 , wherein reconfiguration of the one or more of the characteristics of the lithographic process increases latitude of at least one of the design variables.

17. The computer program product of claim 9 , wherein the bandwidth is a full width at half maximum (FWHM) bandwidth, or wherein the bandwidth is an E95 bandwidth.

18. The method of claim 1 , wherein the bandwidth or the variable is a function of one or more of the plurality of design variables.

19. The computer program product of claim 8 , wherein the bandwidth or the variable is a function of one or more of the plurality of design variables.

20. The computer program product of claim 8 , wherein the reconfiguring the one or more of the characteristics of the lithographic process causes the bandwidth to have a value greater than the minimum that hardware of the radiation source allows.

Assignees

• Cymer LLC
• Asml Netherlands Bv

Inventors

• Conley Willard Earl
• Hsieh Wei-An
• Chiou Tsann-Bim
• Hsieh Cheng-Hsien

Classifications

• G03F7/70575

  Wavelength control, e.g. control of bandwidth, multiple wavelength, selection of wavelength or matching of optical components to wavelength · CPC title

• G03F7/70258

  Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system · CPC title

• G03F7/70441

  Optical proximity correction [OPC] · CPC title

• G03F7/70625

  Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness · CPC title

• G03F1/36

  Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes · CPC title