Pattern-independent and hybrid matching/tuning including light manipulation by projection optics
First Claim
Patent Images
1. A method comprising:
- obtaining, by a computer system comprising hardware, model coefficients representing optical behavior of a lithographic process;
obtaining, by the computer system, model coefficients representing optical behavior of a reference lithographic process separate from the lithographic process to which the lithographic process is to be tuned, wherein tuning comprises substantially matching the optical behavior of the lithographic process to the reference lithographic process,wherein the obtained model coefficients for the lithographic process and the reference lithographic process both comprise a non-diagonalized matrix of elements; and
tuning, by the computer system, the lithographic process to the reference lithographic process by determining values of a plurality of design variables representing adjustable characteristics of the lithographic process that cause a termination condition corresponding to a difference between the obtained model coefficients for the lithographic process and the reference lithographic process to be reached, the lithographic process being configured for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus comprising an illumination source and projection optics.
1 Assignment
0 Petitions
Accused Products
Abstract
Described herein are methods for matching the characteristics of a lithographic projection apparatus to a reference lithographic projection apparatus, where the matching includes optimizing illumination source and projection optics characteristics. The projection optics can be used to shape wavefront in the lithographic projection apparatus. According to the embodiments herein, the methods can be accelerated by using linear fitting algorithm or using Taylor series expansion using partial derivatives of transmission cross coefficients (TCCs).
-
Citations
22 Claims
-
1. A method comprising:
-
obtaining, by a computer system comprising hardware, model coefficients representing optical behavior of a lithographic process; obtaining, by the computer system, model coefficients representing optical behavior of a reference lithographic process separate from the lithographic process to which the lithographic process is to be tuned, wherein tuning comprises substantially matching the optical behavior of the lithographic process to the reference lithographic process, wherein the obtained model coefficients for the lithographic process and the reference lithographic process both comprise a non-diagonalized matrix of elements; and tuning, by the computer system, the lithographic process to the reference lithographic process by determining values of a plurality of design variables representing adjustable characteristics of the lithographic process that cause a termination condition corresponding to a difference between the obtained model coefficients for the lithographic process and the reference lithographic process to be reached, the lithographic process being configured for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus comprising an illumination source and projection optics. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method for tuning a lithographic process to a reference lithographic process, the method comprising:
-
defining, using a computer system comprising hardware, a hybrid multi-variable cost function of a plurality of design variables that represent adjustable characteristics of the lithographic process, the hybrid cost function having first terms comprising a difference between model coefficients for the lithographic process and the reference lithographic process and second terms comprising a difference between lithographic responses of the lithographic process and the reference lithographic process; and reconfiguring, by the computer system, the characteristics of the lithographic process by adjusting the design variables until a termination condition associated with the hybrid cost function is satisfied, the lithographic process being configured for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus comprising an illumination source and projection optics. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
Specification