DE102019215689A1 - WAVE FRONT MANIPULATOR FOR A PROJECTION EXPOSURE PLANT AND A PROJECTION EXPOSURE PLANT AND OPERATING AND MANUFACTURING METHOD THEREFOR - Google Patents

Abstract

The present invention relates to a wavefront manipulator for an optical arrangement, in particular for a projection exposure apparatus for microlithography, and to a corresponding projection exposure apparatus, wherein the wavefront manipulator comprises a refractive optical element (8) with two optically active surfaces (8a, 8b) which are in operation of working light the optical arrangement are irradiated, and with at least one edge surface formed between the two optically active surfaces and is oriented transversely to the optically active surfaces, wherein the wavefront manipulator further comprises a socket (9) in which the refractive optical element is mounted , and at least one optical system (10), with which heating light can be irradiated via the edge surface in the refractive optical element (8), wherein the optical system (10) or several components thereof is formed as a structural unit and / or the socket (9) one Connection arrangement for a connection unit of the optical system (10) for positive and / or non - positive, releasable coupling of the connection unit has. Moreover, the invention relates to a method for producing a corresponding wavefront manipulator and to a method for operating a projection exposure apparatus.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to a wavefront manipulator for an optical arrangement, in particular for a projection exposure apparatus for microlithography, and to a corresponding projection exposure apparatus and a method for producing a corresponding wavefront manipulator and to a method for operating a projection exposure apparatus.

STATE OF THE ART

In projection exposure systems for microlithography, which are used for the production of nanostructured or microstructured components for microelectronics or microsystem technology, it is necessary to correct possible aberrations as far as possible in order to enable a high resolution of the structures to be imaged. Accordingly, it is already known from the prior art to use so-called wavefront manipulators with which the wavefront of the working light passing through the projection exposure apparatus can be manipulated and thus corrected.

Examples of wavefront manipulators which, by irradiating heating light into a refractive optical element laterally, cause a local deformation of the refractive optical element and / or refractive index of the refractive optical element and thus a change in the wavefront of the working light in a corresponding optical arrangement, such as a projection exposure apparatus. when passing through the wavefront through the refractive optical element of the wavefront manipulator, are from the publications WO 2013/044936 A1 . WO 2014/139543 A1 and WO 2014/139990 A1 known. The content of these documents is fully incorporated by reference into the disclosure of the present invention.

The wavefront manipulator known in the prior art has at least one heating light source and corresponding components for generating a plurality of heating light beams and for guiding and coupling them into the refractive optical element. Preferably, a plurality of optical systems for generating a plurality of heating light beams are distributed around the circumference of the refractive optical element arranged to allow distributed over the refractive optical element, a different heating of the refractive optical element and thus a different manipulation of the refractive optical element passing Enable wavefront.

The disadvantage here, however, that a large number of components for the corresponding optical systems are required by the plurality of Heizlichtstrahlen to be produced, the number of which can be in the range of more than 50 or more than 100 partial beams, so that the installation and adjustment effort for Aligning the corresponding beam in the refractive optical element require a lot of effort and long assembly times.

DISCLOSURE OF THE INVENTION

OBJECT OF THE INVENTION

It is therefore an object of the present invention, a wavefront manipulator of the type described, in which Heizlichtstrahlen be radiated laterally to change the optical properties of a wavefront of the working light of an optical arrangement traversed refractive optical element in this, to improve the effect that the assembly effort and the assembly time be reduced, while ensuring a high quality of wavefront manipulation. In particular, a precisely and variably adjustable change in the optical properties of the refractive optical element in locally different regions of the refractive optical element should be achievable.

TECHNICAL SOLUTION

This object is achieved by a wavefront manipulator having the features of claim 1 and a projection exposure apparatus having the features of claim 11 and a method of manufacturing a wavefront manipulator having the features of claim 9 and a method of operating the projection exposure apparatus having the features of claim 12. Advantageous Embodiments are the subject of the dependent claims.

It is assumed that a wavefront manipulator for an optical arrangement, in particular for a projection exposure apparatus for microlithography, we him in the above-mentioned prior art in the publications WO 2013/044936 A1 . WO 2014/139543 A1 and WO 2014/139990 A1 is described, namely of a wavefront manipulator having a refractive optical element with two optically active surfaces, which are irradiated in operation by the working light of the optical arrangement, so for example the projection exposure system. The refractive optical element has at least one edge surface, which is formed between the two optically active surfaces and is oriented transversely to the optically active surfaces. The refractive optical element is mounted in a socket and has at least one optical system with which heating light can be irradiated via the edge surface into the refractive optical element.

The present invention proposes to simplify the assembly and to shorten the installation time, the optical system of such a wavefront manipulator or more components thereof as a structural unit, so that an optical system can be mounted as a unit or with a few units on the refractive optical element , Although the corresponding components of the optical system must be mounted in the one or more units in the formation of one or more units, but by the independent assembly of the units, which then only need to be joined together, the assembly is simplified and the units can be separately check their functionality and, if necessary, improve them so that they meet the requirements. Accordingly, it is easier to detect and correct errors.

Accordingly, a method for producing a wavefront manipulator is claimed, in which one or more units of the optical system and the refractive optical element are manufactured separately and then assembled, wherein the structural unit of the optical system with a coupling unit for coupling the heating light rays or in the refractive optical element is adjusted prior to assembly with the refractive optical element.

Moreover, it is alternatively or additionally proposed to form a connection arrangement on the holder for the refractive optical element with which the refractive optical element of the wavefront manipulator can be held and stored in an optical arrangement, such as a microlithography projection exposure apparatus, with a connection unit cooperates with the optical system, so that a positive and / or non-positive, releasable connection of the connection unit of the optical system with the connection arrangement of the version of the refractive optical element is given. As a result, an optical system of the wavefront manipulator can be connected in a defined manner to the refractive optical element without requiring further testing of the functionality, so that an optical system already tested in advance for its functionality can be arranged in the wavefront manipulator without further testing and adjustment effort , This also makes it possible to significantly reduce the cost of assembly and the time required for this.

In addition, this makes it possible to exchange an optical system of the wavefront manipulator in a simple manner, so that different optical systems can be used in the wavefront manipulator depending on the required wavefront manipulation.

The optical system of the wavefront manipulator may comprise at least one light source unit with one or more heating light sources for providing heating light. However, it is also possible for a plurality of optical systems of the wavefront manipulator to share a common light source unit or a common heat light source. Furthermore, the optical system can have a beam shaping and / or beam guidance unit for shaping and / or guiding one or more heating light beams and at least one coupling unit for coupling the heating light beam or beams into the refractive optical element. These units can be formed by a variety of components, wherein the optical system is preferably modular and, for example, the light source unit and / or the beam shaping and / or beam guiding unit and / or the coupling unit can each represent a module in the form of a structural unit. In addition, further combinations of components of the optical system and / or of corresponding units can be made into a structural unit. In particular, it is possible for the optical system to be implemented as a single structural unit.

For the simple and defined arrangement of the optical system or at least the coupling-in unit, the connection arrangement of the socket and the connection unit of the optical system can comprise suitable mechanical connection and / or closure elements which enable a positive and / or non-positive connection. In particular, recesses and projections may be provided which can mutually engage with each other. In addition, the connecting and / or closing elements may comprise clamping elements, screw connections, bayonet locks, stops and the like.

list of figures

• 1 eine Darstellung einer Projektionsbelichtungsanlage,
• 2 eine Darstellung eines Wellenfrontmanipulators,
• 3 eine Darstellung eines optischen Systems für einen Wellenfrontmanipulator,
• 4 eine Darstellung eines Wellenfrontmanipulators gemäß der Erfindung,
• 5 eine Darstellung eines weiteren Wellenfrontmanipulator gemäß der Erfindung,
• 6 eine Darstellung eines Lichtleitermoduls,
• 7 eine Draufsicht auf das Lichtleitermodul aus 6,
• 8 eine Darstellung einer Einkoppeleinheit und in
• 9 eine Darstellung einer Justiereinrichtung für das Lichtleitermodul aus 6 in Verbindung mit einer Fokussieroptik als Einkoppeleinheit.

The accompanying drawings show in a purely schematic manner in FIG

• 1 a representation of a projection exposure apparatus,
• 2 a representation of a wavefront manipulator,
• 3 a representation of an optical system for a wavefront manipulator,
• 4 a representation of a wavefront manipulator according to the invention,
• 5 a representation of another wavefront manipulator according to the invention,
• 6 a representation of a fiber optic module,
• 7 a plan view of the fiber optic module 6 .
• 8th a representation of a coupling unit and in
• 9 an illustration of an adjusting device for the optical fiber module 6 in conjunction with a focusing optics as coupling unit.

EMBODIMENTS

Further advantages, characteristics and features of the present invention will become apparent from the following detailed description of the embodiments. However, the invention is not limited to these embodiments.

The 1 shows a representation of a projection exposure system 1 with a light source 2 that the working light for the projection exposure system 1 provides. The projection exposure machine 1 also has a lighting system 3 on, with which the working light of the light source 2 is processed to a reticle 4 to illuminate which has structures on a wafer 6 to be displayed in a miniaturized way. This is a projection lens 5 provided, which according to the invention, a wavefront manipulator 7 comprising a refractive optical element 8th in the form of a plate, the two optically active surfaces 8a and 8b that is from the work light of the production exposure equipment 1 is irradiated.

The refractive optical element 8th of the wavefront manipulator 7 is in a version 9 stored, which according to the invention an optical system 10 for heating the refractive optical element 8th is arranged with heating light.

The 2 shows an example of a wavefront manipulator 7 in a top view. Accordingly, it can be seen here that the refractive optical element 8th is formed as a circular disc, which is perpendicular to the image plane, an edge surface 17 has, over which Heizlichtstrahlen 12 of several optical systems 10a . 10b and 10c into the refractive optical element 8th be irradiated to there the refractive optical element 8th to heat and thereby lead to a manipulation of the wavefront of the working light, which is the refractive optical element according to the representation of the projection lens 5 in the 1 passes.

Again 2 it can be seen, are several optical systems 10a . 10b and 10c for irradiation of heating light in the refractive optical element 8th intended. The corresponding optical systems 10a . 10b and 10c each have a heating light source 11 on which Heizlichtstrahlen 12 generated by a focusing optics 13 be irradiated in several partial beams in the refractive optical element.

Such as in the WO 2013/044936 A1 . WO 2014/139543 A1 or WO 2014/139990 A1 described, various embodiments of optical systems for generating Heizlichtstrahlen and irradiation thereof in a refractive optical element can be realized. The corresponding optical systems for generating and irradiating heating light in refractive optical elements, as disclosed in said prior art, are incorporated herein by reference.

The 3 shows a further embodiment of an optical system with a light source unit with a plurality of Heizlichtquellen 11 in the form of LEDs and a coupling optics 14 , with which the heating light of the light source unit in light guide 15 , such as glass fibers, can be coupled. The light guides 15 , which constitute a beam guiding unit, have at their end a coupling-out optics 16 on, with the heating light back out of the light guides 15 is decoupled. Subsequently, there is a focusing optics 13 with which the heating light in a variety of rays in the refractive optical element 8th a wavefront manipulator is introduced.

According to the invention, various components of the optical systems, as shown for example in the 2 and 3 are shown, merged into building units. For example, heating light sources 11 as a light source unit represent a structural unit or the light guide 15 can represent a structural unit in the form of a beam guiding unit, as in 3 shown. In addition, the focusing optics 13 be formed in a structural unit as a coupling unit.

The 4 shows that an optical system 10 can be formed overall as a structural unit and in a simple manner via a positive and / or non-positive connection to the socket 9 can be arranged so that the optical system 10 in a defined manner with respect to the refractive optical element 8th is arranged and the heating light 12 in a defined way over the edge surface 17 of the refractive optical element 8th into the refractive optical element 8th can be initiated.

In addition, it is also possible to construct a modular optical system and several units 18 . 19 . 20 to provide, as in 5 is shown. The 5 shows an optical system with three units, namely a coupling unit 18 , a beam generating and / or guiding unit 19 and a light source unit 20 , In such an embodiment with a plurality of modules or units, for example, the coupling unit 18 again in a positive and / or non-positive connection to the socket 9 be arranged so that a defined orientation of the coupling unit 18 with respect to the refractive optical element 8th is given and thus the heating light 12 in a defined manner in the refractive optical element 8th is irradiated. The other modules or modules, such as the beam guiding unit 19 and the light source unit 20 can then suitably with the coupling unit 18 get connected.

Both the optical system 10 the embodiment of the 4 , which is designed as a single unit, as well as the coupling unit 18 of the optical system used in 5 can be shown by the positive and / or non - positive connection with the socket 9 be replaced in a simple manner, since the positive and / or non-positive connection represents a detachable connection. Accordingly, the optical systems 10 can be exchanged in a simple manner and with a changed requirement profile to the wavefront manipulator can by replacing the optical system or systems 10 for the provision of heated light a simple adjustment can be made.

The 6 and 7 show a fiber optic module 21 , which as a structural unit, for example, together with a focusing optics 32 (please refer 9 ) may be formed as a coupling unit. The fiber optic module 21 has a base body in which a groove-like depression for forming a light guide receptacle 22 is formed in the glass fibers 23 . 24 are inserted as a light guide. The glass fibers 23 and 24 can by appropriate spacers 26 in the light guide 22 be positioned. The glass fibers 23 and 24 can also be arranged on the base body by cohesive connection, for example by means of an adhesive.

The fiber optic module 21 has plug feet 25 on, for example, in corresponding recesses in the version 9 for the refractive optical element 8th can be inserted so that a positive connection results. In addition, a focusing optics 32 in conjunction with the fiber optic module 21 be provided as they are in 9 is shown, so that a total of one coupling unit results. For this purpose, a base plate (not shown) may be provided, the recesses for receiving the plug feet 25 of the fiber optic module 21 and other connecting elements for connection to the focusing optics 32 includes. The base plate can in a corresponding manner by positive connection elements on the socket 9 of the wavefront manipulator.

The 8th shows a further embodiment of a coupling unit 27 , has been dispensed with a focusing optics and the glass fibers 28 . 29 . 30 be aligned accordingly to allow a desired irradiation of the Heizlichtstrahlen in the refractive optical element. For positioning the glass fibers 28 . 29 and 30 are again spacers 31 provided, wherein the glass fibers 28 . 29 and 30 can also be firmly bonded via an adhesive after the appropriate positioning.

An optical system or parts thereof, such as the coupling unit, for example in the form with the light guide module 21 and the focusing optics 32 according to the representation of 9 , can before installation in the wavefront manipulator, so for example before the arrangement of the coupling unit to the socket 9 the wavefront manipulator in an adjustment device are checked and adjusted, taking on a screen 33 the light pattern of the Heizlichtstrahlen generated by the coupling unit can be displayed and checked. Are the points of light of the Heizlichtstrahlen at the predetermined locations on the screen 33 , so the coupling unit corresponds to the optical fiber module 21 and the focusing optics 32 the specification and can be installed accordingly in the wavefront manipulator or in particular mounted on the socket. If there are deviations between the required light pattern and that on the screen 33 shown light pattern, so the light guide module 21 and the focusing optics 32 be adjusted accordingly before final assembly.

Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that the invention is not limited to these embodiments, but rather modifications are possible in the manner that individual features omitted or otherwise Combinations of features can be realized without departing from the scope of the appended claims. In particular, the present disclosure includes all combinations of the individual features shown in the various embodiments, so that individual features that are described only in connection with an embodiment can also be used in other embodiments or combinations of individual features not explicitly shown.

LIST OF REFERENCE NUMBERS

1

Projection exposure system

2

light source

3

lighting system

4

reticle

5

projection lens

6

wafer

7

Wavefront manipulator

8th

refractive optical element

8a, 8b

optically effective surfaces

9

version

10, 10a, 10b, 10c

optical system

11

Heizlichtquelle

12

Heizlichtstrahlen

13

Fodussieroptik

14

coupling optic

15

optical fiber

16

outcoupling optics

17

edge surface

18

coupling unit

19

Beam generating and / or guiding unit

20

Light source unit

21

Light module

22

Fiber storage

23, 24

glass fibers

25

plug the foot

26

spacer

27

coupling unit

28, 29, 30

glass fibers

31

spacer

32

focusing optics

33

screen

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2013/044936 A1 [0003, 0008, 0021]
• WO 2014/139543 A1 [0003, 0008, 0021]
• WO 2014/139990 A1 [0003, 0008, 0021]

Claims (12)

Wavefront manipulator for an optical arrangement, in particular for a projection exposure apparatus for microlithography, having a refractive optical element (8) with two optically active surfaces (8a, 8b), which are irradiated during operation of working light of the optical arrangement, and at least one edge surface (17 ), which is formed between the two optically active surfaces and oriented transversely to the optically active surfaces, wherein the wavefront manipulator further comprises a socket (9) in which the refractive optical element is mounted, and at least one optical system (10), with which heating light (12) can be radiated into the refractive optical element (8) via the edge surface (17), characterized in that the optical system (10) or several components thereof are used as a structural unit (10, 18, 19, 20, 21) is formed and / or the socket (9) has a connection arrangement for a connection unit of the optical system (10) for fo Having rm - and / or non-positive, releasable coupling of the connection unit. Wave front manipulator after Claim 1 , characterized in that the optical system (10) comprises at least one light source unit (20) for providing heating light, a beam shaping and / or beam guiding unit (19) for shaping and / or guiding one or more heating light beams and at least one coupling unit (18). for coupling the heating light beam or rays into the refractive optical element. Wave front manipulator after Claim 2 , characterized in that the optical system is constructed in modules, wherein in particular the light source unit (20) and / or the beam shaping and / or beam guiding unit (19) and / or the coupling unit (18) constitute a module in the form of a structural unit. Wavefront manipulator according to one of the preceding claims, characterized in that the optical system (10) comprises one or more components of the group comprising lasers, LEDs, optical fibers, glass fibers, refractive optical elements, optical lenses, reflective optical elements, mirrors, mirror assemblies, Covers diaphragms, beam splitters, coupling-in and coupling-out optics for optical fibers, focusing optics and absorbers. Wavefront manipulator according to one of the preceding claims, characterized in that a plurality of optical systems have a common light source unit. Wavefront manipulator according to one of the preceding claims, characterized in that the connection arrangement of the socket (9) and the connection unit of the optical system (10) comprise mechanical connection and / or closure elements which enable exact positioning of connection arrangement and connection unit, in particular one or more Group of components comprising recesses, projections, clamping elements, screw connections, bayonet locks and stops. Wavefront manipulator according to one of the Claims 2 to 6 , characterized in that the connection unit is formed in unit with the coupling unit (18). Wavefront manipulator according to one of the preceding claims, characterized in that the wavefront manipulator has a plurality of identical or different optical systems (10). Method for producing a wave front manipulator (7) according to one of the preceding claims, in which one or more structural units (18, 19, 20, 21) of the optical system (10) and the refractive optical element (8) are produced separately from one another and subsequently assembled wherein the assembly of the optical system is adjusted with a coupling unit (18) for coupling the heating light beam (s) into the refractive optical element prior to assembly with the refractive optical element (8). Method according to Claim 9 , characterized in that after the assembly of refractive optical element and the structural unit of the optical system with the coupling unit (18) these are no longer adjusted. Projection exposure apparatus for microlithography with a wavefront manipulator according to one of the Claims 1 to 8th , Method for operating a projection exposure apparatus according to Claim 11 in which successively different optical systems (10) are used in the wavefront manipulator (7) and are exchanged as a function of the required wavefront manipulation.

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