Process window based on defect probability

Patent metadata

Field	Value
Publication number	US-11822255-B2
Application number	US-202117389842-A
Country	US
Kind code	B2
Filing date	Jul 30, 2021
Priority date	Dec 22, 2017
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

A method including obtaining (i) measurements of a parameter of the feature, (ii) data related to a process variable of a patterning process, (iii) a functional behavior of the parameter defined as a function of the process variable based on the measurements of the parameter and the data related to the process variable, (iv) measurements of a failure rate of the feature, and (v) a probability density function of the process variable for a setting of the process variable, converting the probability density function of the process variable to a probability density function of the parameter based on a conversion function, where the conversion function is determined based on the function of the process variable, and determining a parameter limit of the parameter based on the probability density function of the parameter and the measurements of the failure rate.

First claim

What is claimed is:

1. A method comprising:
obtaining (i) a parameter limit of a parameter of a patterning process based on failure rate measurements of the patterning process, and (ii) a probability density function of the parameter defined as a function of a process variable of the patterning process and a variance of the process variable;
determining an estimated failure rate of the patterning process based on the parameter limit and the probability density function of the parameter; and
identifying, by a hardware computer system, a process window of the patterning process in terms of the process variable such that the estimated failure rate of the parameter is less than a selected threshold.

2. The method according to claim 1 , wherein the identifying of the process window involves determining a range of the process variable between an intersection of the estimated failure rate and the selected threshold.

3. The method according to claim 1 , wherein the selected threshold is based on a selected yield of the patterning process.

4. The method according to claim 1 , wherein the patterning process is configured to adjust of one or more apparatuses of the patterning process based on the process window.

5. The method according to claim 4 , wherein the one or more apparatuses includes a lithographic apparatus configured to perform patterning on a substrate based on the process window.

6. The method of claim 1 , wherein the parameter of the patterning process is a critical dimension and the process variable is a dose.

7. A computer product comprising a non-transitory computer-readable medium having instructions, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
obtain (i) a parameter limit of a parameter of a patterning process based on failure rate measurements of the patterning process, and (ii) a probability density function of the parameter defined as a function of a process variable of the patterning process and a variance of the process variable;
determine an estimated failure rate of the patterning process based on the parameter limit and the probability density function of the parameter; and
identify a process window of the patterning process in terms of the process variable such that the estimated failure rate of the parameter is less than a selected threshold.

8. A method comprising:
obtaining a parameter limit of a parameter of a patterning process; and
determining, by a hardware computer system, an estimated failure rate of the patterning process using a function based on the parameter limit and on a probability density function of the parameter or a cumulative distribution function of the probability density function, wherein the probability density function of the parameter is defined as a function of a process variable of the patterning process and a variance of the process variable.

9. The method according to claim 8 , wherein the patterning process is configured to adjust one or more apparatuses of the patterning process based on the estimated failure rate.

10. The method according to claim 9 , wherein the one or more apparatuses includes a lithographic apparatus configured to perform patterning on a substrate.

11. The method according to claim 8 , wherein the parameter of the patterning process is a critical dimension and the process variable is a dose.

12. The method according to claim 8 , further comprising identifying a process window of the patterning process in terms of the process variable based on the estimated failure rate of the parameter.

13. The method according to claim 8 , wherein the function based on at least the parameter limit is based on the probability density function of the parameter.

14. A computer product comprising a non-transitory computer-readable medium having instructions, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
obtain a parameter limit of a parameter of a patterning process; and
determine an estimated failure rate of the patterning process using a function based on the parameter limit and on a probability density function of the parameter or a cumulative distribution function of the probability density function, wherein the probability density function of the parameter is defined as a function of a process variable of the patterning process and a variance of the process variable.

15. A method comprising:
obtaining (i) a parameter limit of a parameter of a patterning process, and (ii) a probability density function of the parameter defined as a function of a process variable of the patterning process;
determining an estimated failure rate of the patterning process based on the parameter limit and the probability density function of the parameter; and
identifying, by a hardware computer system, a process window of the patterning process in terms of the process variable based on the estimated failure rate.

16. The method according to claim 15 , wherein the identifying of the process window involves determining a range of the process variable between an intersection of the estimated failure rate and a selected threshold for the estimated failure rate.

17. The method according to claim 15 , wherein the patterning process is configured to adjust one or more apparatuses of the patterning process based on the process window.

18. The method according to claim 17 , wherein the one or more apparatuses includes a lithographic apparatus configured to perform patterning on a substrate based on the process window.

19. The method according to claim 15 , wherein the parameter of the patterning process is a critical dimension and the process variable is a dose.

20. A computer product comprising a non-transitory computer-readable medium having instructions, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
obtain (i) a parameter limit of a parameter of a patterning process, and (ii) a probability density function of the parameter defined as a function of a process variable of the patterning process;
determine an estimated failure rate of the patterning process based on the parameter limit and the probability density function of the parameter; and
identifying, by a hardware computer system, a process window of the patterning process in terms of the process variable based on the estimated failure.

Assignees

• Asml Netherlands Bv

Inventors

• Slachter Abraham
• Hunsche Stefan
• Tel Wim Tjibbo
• Van Oosten Anton Bernhard
• Van Ingen Schenau Koenraad
• Rispens Gijsbert
• Peterson Brennan

Classifications

• G03F1/36

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

• G03F1/70

  Adapting basic layout or design of masks to lithographic process requirements, e.g., second iteration correction of mask patterns for imaging · CPC title

• G03F7/70641

  Focus · CPC title

• G03F7/70525

  Controlling normal operating mode, e.g. matching different apparatus, remote control or prediction of failure · CPC title

• G03F7/70633 Primary

  Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching · CPC title