Projection exposure apparatus including at least one mirror

Patent metadata

Field	Value
Publication number	US-9910364-B2
Application number	US-201615298323-A
Country	US
Kind code	B2
Filing date	Oct 20, 2016
Priority date	Oct 21, 2015
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A microlithographic projection exposure apparatus includes: a projection lens for imaging mask structures via an exposure radiation including at least one optical element and at least one manipulator; a read-in device for reading in application-specific structure information defining at least one property of an angular distribution of the exposure radiation upon entering the projection lens; and a travel establishing device for establishing a travel command defining a change to be made in an optical effect of the at least one optical element by manipulation of a property of the optical element via the at least one manipulator along a travel. The travel establishing device is configured to establish the travel command in an at least two-stage optimization.

First claim

What is claimed is:

1. An apparatus, comprising:
a projection lens configured to image mask structures via exposure radiation, the projection lens comprising an optical element and a manipulator;
a read-in device configured to read in application-specific structure information defining a property of an angular distribution of the exposure radiation upon entering the projection lens; and
a travel establishing device configured to establish a travel command defining a change to be made in an optical effect of the optical element via manipulation of a property of the optical element via the manipulator along a travel,
wherein:
the travel establishing device is configured to establish the travel command in an at least two-stage optimization;
a first stage of the optimization is configured to establish an approximation of the travel command from a state characterization of the projection lens via a first optimization algorithm based on a predefined standard angular distribution of the exposure radiation upon entering the projection lens;
a second stage of the optimization is configured to establish an optimization result of the travel command via a second optimization algorithm from the approximation of the travel command taking into account the application-specific structure information; and
the apparatus is a microlithographic projection exposure apparatus.

2. The apparatus of claim 1 , wherein the application-specific structure information comprises: a) an indication regarding the illumination mode used during the imaging of the mask structures; and/or b) an indication regarding a structure type of the mask structures.

3. The apparatus of claim 2 , wherein:
the travel command comprises travel settings assigned to a multiplicity of manipulator degrees of freedom of the manipulator;
travel settings assigned to a first set of the manipulator degrees of freedom serve as optimization variables in the first stage of the optimization; and
travel settings assigned to a second set of the manipulator degrees of freedom serve as optimization variables in the second stage of the optimization.

4. The apparatus of claim 3 , wherein the first set of the manipulator degrees of freedom is mutually exclusive of the second set of the manipulator degrees of freedom.

5. The apparatus of claim 4 , wherein the second set of the manipulator degrees of freedom contains fewer manipulator degrees of freedom than the first set of the manipulator degrees of freedom.

6. The apparatus of claim 5 , wherein the second set of the manipulator degrees of freedom comprises overlay degrees of freedom of the projection lens such that manipulation via the manipulator along one of the overlay degrees of freedom or along a combination of a plurality of the overlay degrees of freedom brings about a change in an overlay aberration of the projection lens.

7. The apparatus of claim 6 , wherein the state characterization of the projection lens comprises aberration parameters characterizing an imaging quality of the projection lens, and the second stage of the optimization is effected on the basis of a subset of the aberration parameters whose elements in each case relate to an overlay aberration of the projection lens.

8. The apparatus of claim 7 , wherein the first optimization algorithm is based on a merit function in a Tikhonov regularization which contains implicit constraints described with the aid of weighting parameters, and the values of the weighting parameters are left unchanged when the first optimization algorithm is executed.

9. The apparatus of claim 8 , wherein the travel establishing device is configured to establish the travel command in less than one second.

10. The apparatus of claim 9 , wherein the travel establishing device is configured to carry out the two-stage optimization in the context of a maintenance adjustment and to perform the second stage of the optimization, in each case proceeding from the approximation of the travel command, for different items of application-specific structure information.

11. The apparatus of claim 1 , wherein the state characterization of the projection lens comprises aberration parameters characterizing an imaging quality of the projection lens, and the second stage of the optimization is effected on the basis of a subset of the aberration parameters whose elements in each case relate to an overlay aberration of the projection lens.

12. The apparatus of claim 1 , wherein:
the travel command comprises travel settings assigned to a multiplicity of manipulator degrees of freedom of the manipulator;
travel settings assigned to a first set of the manipulator degrees of freedom serve as optimization variables in the first stage of the optimization; and
travel settings assigned to a second set of the manipulator degrees of freedom serve as optimization variables in the second stage of the optimization.

13. A method of controlling a microlithographic projection exposure apparatus comprising a projection lens for imaging mask structures, the projection lens comprising an optical element and a manipulator, the method comprising:
reading in application-specific structure information defining a property of an angular distribution of the exposure radiation upon entering the projection lens; and
establishing a travel command defining a change to be made in an optical effect of the optical element by manipulation of a property of the optical element via the manipulator along a travel in an optimization comprising first and second stages,
wherein:
in the first stage of the optimization, an approximation of the travel command is established from a state characterization of the projection lens via a first optimization algorithm based on a predefined standard angular distribution of the exposure radiation upon entering the projection lens; and
in the second stage of the optimization, via a second optimization algorithm an optimization result of the travel command is established from the approximation of the travel command taking into account the application-specific structure information.

14. the method of claim 13 , wherein the optimization is repeated at time intervals of at least one week in the context of a standard set-up.

15. The method of claim 14 , wherein, before a repetition of the optimization, the second stage of the optimization is carried out separately at least once.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Bittner Boris
• Wabra Norbert
• Schneider Sonja
• Schoemer Ricarda
• Rist Stefan

Classifications

• G03F7/70191 Primary

  Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like · CPC title

• G03F7/7015

  Details of optical elements · CPC title

• G03F7/70258 Primary

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

• G03F7/705

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