Projection exposure apparatus with at least one manipulator

Patent metadata

Field	Value
Publication number	US-9927714-B2
Application number	US-201715484402-A
Country	US
Kind code	B2
Filing date	Apr 11, 2017
Priority date	Nov 20, 2014
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A microlithography projection exposure apparatus includes a projection lens at least one manipulator to change an optical effect of at least one optical element of the projection lens, and a travel establishing device for generating a travel command for the at least one manipulator.

First claim

What is claimed is:

1. An apparatus, comprising:
a projection lens configured to image mask structures, the projection lens comprising an optical element;
a manipulator configured to change an optical effect of the optical element by manipulating a property of the optical element along a travel; and
a device configured to generate a travel command for the manipulator,
wherein:
the device is configured to generate a first travel command from a first state characterization of the projection lens by executing an optimization algorithm comprising a work variable;
the optimization algorithm is configured to change a value of the work variable in the course of the optimization and to save the value of the work variable that is present at the end of the optimization as a transfer value;
the device is configured to generate a second travel command from a second state characterization of the projection lens by repeated execution of the optimization algorithm and in the process to use the saved transfer value as a start value of the work variable;
the second state characterization is updated relative to the first state characterization, and
the apparatus a microlithography projection exposure apparatus.

2. The apparatus of claim 1 , wherein the optimization algorithm is configured to optimize a merit function taking account of a constraint described outside the merit function.

3. The apparatus of claim 2 , wherein the constraint described outside the merit function comprises a fixed boundary for the travel performed by the at least one manipulator.

4. The apparatus of claim 1 , further comprising a state generator configured to provide the first and second state characterizations of the projection lens.

5. The apparatus of claim 1 , wherein the work variable comprises a limit value for the travel of the manipulator, and the limit value is set at times during the optimization process.

6. The apparatus of claim 1 , wherein:
the optimization algorithm is configured to optimize a merit function taking account of a constraint;
the constraint specifies a limit value for a parameter; and
the work variable includes information as to whether the relevant parameter deviates from the limit value by a maximum of 10% at a given point in time.

7. The apparatus of claim 1 , wherein the work variable comprises a Lagrange variable of the Karush-Kuhn-Tucker condition.

8. The apparatus of claim 1 , wherein the work variable comprises a change direction of an optimization variable that is chosen by the optimization algorithm at the given point in time.

9. The apparatus of claim 1 , wherein the optimization algorithm is configured to change the value of the work variable iteratively in the course of the optimization.

10. The apparatus of claim 1 , wherein the optimization algorithm is configured to establish the second travel command in less than one second.

11. The apparatus of claim 1 , wherein:
the state characterizations in each case comprise a set of aberration parameters characterizing the imaging quality of the projection lens; and
the state characterization is updated so frequently that a plurality of selected aberration parameters of the second state characterization deviate from the corresponding aberration parameter of the first state characterization in each case by less than 10%.

12. The apparatus of claim 11 , wherein the selected aberration parameters comprise at least two Zernike coefficients from a group of Zernike coefficients Zn where n≤100, and the assigned Zernike polynomials are odd-wave Zernike polynomials.

13. The apparatus of claim 1 , wherein the device is configured to generate a multiplicity of further travel commands by repeated execution of the optimization algorithm during the exposure process and to use in each case the transfer value stored during the generation of the preceding travel command as a respective start value of the work variable.

14. The apparatus of claim 13 , wherein the multiplicity of further travel commands to be generated during the exposure process comprises at least fifty travel commands.

15. The apparatus of claim 1 , wherein the state generator is configured to update the state characterization of the projection lens multiply during an exposure process in which the mask structures of a reticle are imaged onto a substrate once by means of the projection lens.

16. A method, comprising:
using the apparatus of claim 1 to image mask structures.

17. A method of controlling a microlithography projection exposure apparatus comprising an optical element, the method comprising:
generating a first travel command from a first state characterization of the projection lens by executing an optimization, wherein in the course of the optimization a value of a work variable is changed and the value of the work variable that is present at the end of the optimization is saved as a transfer value;
changing an optical effect of at least one of the optical elements by manipulating a property of the optical element along a travel defined by the first travel command; and
generating a second travel command from a further second characterization of the projection lens, the second state characterization being updated relative to the first state characterization by repeated execution of the optimization,
wherein the saved transfer value is used as a start value of the work variable.

18. The method of claim 17 , wherein the optimization is carried out by optimization of a merit function taking account of a constraint described outside the merit function.

19. The method of claim 17 , wherein the work variable comprises a limit value for the travel, and the limit value is set at times during the optimization process.

20. The method of claim 17 , further comprising using the apparatus to image mask structures.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Bittner Boris
• Rist Stefan

Classifications

• G03F7/70233

  Optical aspects of catoptric systems, i.e. comprising only reflective elements, e.g. extreme ultraviolet [EUV] projection systems · CPC title

• G03F7/70266 Primary

  Adaptive optics, e.g. deformable optical elements for wavefront control, e.g. for aberration adjustment or correction · CPC title

• G03F7/705

  Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions · CPC title

• G03F7/706849

  Irradiation branch, e.g. optical system details, illumination mode or polarisation control · CPC title

• G03F7/70275

  Multiple projection paths, e.g. array of projection systems, microlens projection systems or tandem projection systems · CPC title