DE102022202355A1 - Micromirror assembly, manufacturing method for manufacturing a micromirror assembly and method for tilting a mirror surface - Google Patents

Abstract

The invention relates to a micromirror assembly (1) of a facet arrangement (2) of a facet mirror (119, 121). The micromirror assembly (1) has a base area (5), a carrier area (3) spaced from the base area (5) with a mirror surface (4) facing away from the base area (5), and a micromechanical assembly (7) with a spring element (8). and a separate heat-conducting element (9). The spring element (8) and the heat-conducting element (9) are each arranged at a distance from one another between the base area (5) and the carrier area (3) and are designed such that the carrier area (3) has at least two rotational degrees of freedom (R1 ,2) can be tilted.

Description

The present invention relates to a micromirror assembly of a facet arrangement of a facet mirror, having a base area and a carrier area spaced apart from the base area with a mirror surface.

The invention also relates to a facet arrangement of a facet mirror, having a plurality of micro-mirror assemblies.

The invention also relates to a facet mirror, in particular a field facet mirror or a pupil facet mirror for a projection exposure system, and a projection exposure system for microlithography.

The invention further relates to a manufacturing method for manufacturing a micromirror assembly of a facet arrangement of a facet mirror, and a method for tilting a mirror surface of a facet mirror relative to a base region.

Projection exposure systems or lithography systems are used to produce integrated circuits with high precision. Here, the light from a radiation source is directed to a wafer to be exposed via optical elements such as mirrors and/or lenses. The arrangement, position and geometry of the optical elements make a decisive contribution to the quality of the exposure. Due to the progressive miniaturization of semiconductor circuits, the requirements for the resolution and the accuracy of the projection exposure systems are increasing in equal measure. Correspondingly high demands are placed in particular on their optical elements and the actuation of the optical elements.

In order to achieve a particularly high resolution, EUV (“Extreme Ultra Violet”) projection exposure systems have been used for a number of years. In the illumination system of such projection exposure systems, individual field facets up to individual segments of field facets are generally assigned to differently positioned pupil facets (segments). The facet mirrors can be implemented using individually tiltable micro-mirrors.

In the case of EUV projection exposure systems, care must also be taken to ensure that the mirrors do not exceed a defined temperature, because as a rule one third of the radiation incident on the mirrors is absorbed. Finally, the thermal load deposited in the mirror optics must be dissipated in order to avoid optical aberrations or imaging errors and to ensure consistently high imaging accuracy. In order to achieve the highest possible filling factor in mirror modules made from micromirrors, the actuators, sensors and other micromechanical elements must be arranged below the mirror surface. The thermal resistance of this micromechanical assembly between the carrier area for the mirror surface and the base area of the micromirror assembly is of particularly great importance.

Dissipating the heat via the micromechanical components is often problematic.

Previous solutions for enabling the movement of the micromirror around two tilting axes usually include leaf spring elements that together form a cardanic joint (cf., for example, DE 10 2015 204 874 A1 ). In order to achieve the greatest possible freedom of movement with simple actuator means, the individual spring elements must have a low degree of bending stiffness. At the same time, however, the heat must be dissipated from the mirror surface into the base area of the micromirror assembly via the spring elements. This requirement is in contrast to the requirement for low bending stiffness.

There is therefore a need to provide a micromechanical assembly with low flexural rigidity and at the same time the lowest possible thermal resistance.

In view of this, the object of the present invention is to provide a micromirror assembly with a micromechanical assembly that has a low flexural rigidity for tilting a mirror surface and is nevertheless able to efficiently dissipate the heat from the mirror surface.

The present invention is also based on the object of providing a facet arrangement, a facet mirror and a projection exposure system, each of which has at least one micromirror assembly with a micromechanical assembly that has a low flexural rigidity for tilting a mirror surface and which is nevertheless able to efficiently dissipate the heat from the mirror surface .

It is also an object of the invention to propose a production method by means of which a micromirror assembly can be produced which has a micromechanical assembly which has low flexural rigidity for tilting a mirror surface and which is nevertheless able to efficiently dissipate the heat from the mirror surface.

Furthermore, it is the object of the invention to propose a method for tilting a mirror surface, which allows flexible and precise positioning of the mirror surface, while at the same time efficiently dissipating heat from the mirror surface.

The object is achieved for the micromirror assembly, the facet arrangement, the facet mirror, the projection exposure system, the manufacturing method and the method for tilting the mirror surface with the respective independent claims. The dependent claims and the features described below relate to advantageous embodiments and variants of the invention.

A micromirror assembly of a facet arrangement of a facet mirror is provided, having a base area and a carrier area spaced apart from the base area with a mirror surface facing away from the base area.

The carrier area can in particular be formed in one piece with the mirror surface—for example, the carrier area can form a mirror body, the mirror body being correspondingly coated on the surface facing the radiation or processed in some other way in order to form the mirror surface. In principle, however, any configuration can be provided, for example also a multi-part division, with the carrier area being connected to a separate mirror body or a separate mirror surface (in particular materially).

The carrier area can preferably be moved, in particular tilted, relative to the base area, as will be described below.

The base area is preferably the stationary part of the micro-mirror assembly, which is formed, for example, on a common substrate of a plurality of micro-mirror assemblies.

The micromirror assembly has a micromechanical assembly with at least one spring element and at least one separate heat-conducting element. The spring element and the heat-conducting element are spaced apart from one another and are each arranged and configured between the base area and the carrier area in such a way that the carrier area can be tilted relative to the base area along at least two rotational degrees of freedom.

The micromechanical assembly can in particular have an articulated connection, preferably a solid articulated connection, which is formed by the at least one spring element and the at least one heat-conducting element. However, the micromechanical assembly can also have other components, in particular electronic components (sensors, actuators, etc.), as will be described below, and can therefore also be referred to as a microelectromechanical assembly.

The inventors have recognized that the integration of an additional heat conducting element (or possibly also several heat conducting elements) in addition to the at least one spring element can improve the thermal conductivity without significantly increasing the mechanical rigidity of the micromechanical assembly.

The at least one additional heat-conducting element can advantageously be arranged outside the bending plane of the at least one spring element (preferably offset in the direction of the mirror surface).

The dimensions and/or the geometric course of the at least one heat-conducting element can be determined in such a way that, in combination with the spring element, both the thermal resistance and the flexural rigidity are reduced compared to a system with the spring element but without an additional heat-conducting element (for example compared to a simple leaf spring). In principle, these properties can even be achieved without the integration of additional materials (although the integration of additional materials can certainly further improve the properties of the heat-conducting element).

The micromirror assembly or at least the micromechanical assembly may be a microelectromechanical system (MEMS).

The at least one spring element can form a flexure joint or be at least part of a flexure joint. The at least one heat-conducting element can optionally also form a functional component of the flexure joint, at least to a certain extent, in cooperation with the at least one spring element. The at least one heat conducting element can preferably form a type of idler joint with regard to the at least one spring element, which is designed to be softer in the actuation or tilting direction of the flexure joint formed by the at least one spring element. The softer design of the at least one heat-conducting element can be realized through material properties or the geometry or a combination of material properties and geometry.

In an advantageous development of the invention, it can be provided that the base area, the carrier area and the micromechanical assembly are produced within the scope of a common method for producing microstructures. Preferably, the entire micromirror assembly is fabricated as part of a common microstructure fabrication process.

• - physikalische Gasphasenabscheidung, insbesondere thermisches Verdampfen, Elektronenstrahlverdampfen, Laserstrahlverdampfen, Lichtbogenverdampfen, Molekularstrahlepitaxie, Sputtern, ionenstrahlgestützte Deposition, ICB-Technik und/oder lonenplattieren; und/oder
• - chemische Gasphasenabscheidung, insbesondere plasmaunterstützte chemische Gasphasenabscheidung, heißdraht-aktivierte Gasphasenabscheidung, chemische Niederdruck-Gasphasenabscheidung und/oder metallorganische chemische Gasphasenabscheidung; und/oder
• - plasma-unterstütztes Ätzen; und/oder
• - reaktives Ionentiefenätzen, insbesondere reaktives Silizium-Ionentiefenätzen.

Such a method can include the following method steps:

• - physical vapor deposition, in particular thermal vaporization, electron beam vaporization, laser beam vaporization, arc vaporization, molecular beam epitaxy, sputtering, ion beam assisted deposition, ICB technology and/or ion plating; and or
• - chemical vapor deposition, in particular plasma-enhanced chemical vapor deposition, hot-wire-activated vapor deposition, low-pressure chemical vapor deposition and/or metal-organic chemical vapor deposition; and or
• - plasma-assisted etching; and or
• - Deep reactive ion etching, in particular deep reactive silicon ion etching.

According to a further development of the invention, it can be provided in particular that components of the micromirror assembly are of monolithic design.

Preferably, the entire micromirror assembly is monolithic.

According to a development of the invention, it can be provided in particular that the mirror surface has a spatial extent of less than 10 mm in each direction, preferably less than 6 mm, particularly preferably less than 5 mm, very particularly preferably less than 3 mm. for example less than 1 mm.

Each individual mirror surface can in particular be a reflection surface with dimensions of 1 mm x 1 mm (preferred for example for a field facet mirror), 2 mm x 2 mm, 5 mm x 5 mm or up to 6 mm x 6 mm (preferred for example for a pupil facet mirror ) and larger. The reflection surface can also have smaller dimensions. In particular, it has side lengths in the micrometer or lower millimeter range. The individual mirror surfaces are therefore sometimes also referred to as “micromirrors” in the present case.

The invention is particularly advantageously suitable for use with micromirrors having the dimensions mentioned above or even smaller.

In a development of the invention, it can be provided that one or more components of the micromechanical assembly, in particular the spring element and/or the heat-conducting element, are made of polycrystalline silicon and/or monocrystalline silicon.

Said materials have proven to be particularly suitable and can be processed very well for the present micromechanical application.

In a further development of the invention, it can also be provided that one or more components of the micromechanical assembly, in particular the spring element and/or the heat-conducting element, have a coating which has silicon carbide (e.g. silicon-filtered silicon carbide), gold, silver, aluminum and/or copper .

A coating with said materials can further improve the mechanical, thermal and optical properties of the micromechanical assembly.

The coating can have a layer thickness of 10 nm to 200 nm, for example.

In a particularly preferred development of the invention, it can be provided that the spring element is designed as a leaf spring.

The spring element preferably has a cardanic joint or forms a cardanic joint (e.g. in connection with further spring elements which interact with the spring element in one piece or in several parts), in particular if the spring element is designed as a leaf spring. The ability to tilt along the two rotational degrees of freedom can thus be made possible in a particularly simple and cost-effective manner.

In principle, any joint can be provided in order to enable or guide tilting by at least two rotational degrees of freedom, for example also a point joint.

A plurality of spring elements can preferably be provided in order to enable tilting along at least two rotational degrees of freedom overall. For example, two, three, four or even more spring elements (especially leaf springs) can be provided. Also the uses However, it is possible to use only a single spring element.

In an advantageous development of the invention, it can be provided that the heat-conducting element has a lower flexural rigidity than the spring element with regard to the rotational degrees of freedom by which the carrier area can be tilted relative to the base area.

The heat-conducting element preferably has a bending stiffness that is at least a factor of 2, particularly preferably at least a factor of 4, very particularly preferably at least a factor of 10 (e.g. also at least a factor of 20, 30, 40, 50 or 100) lower than that Spring element with respect to the rotational degrees of freedom by which the carrier area can be tilted relative to the base area. In principle, however, it can also be provided that the heat-conducting element has the same or at least approximately the same rigidity as the spring element.

Provision can be made for the heat-conducting element to be designed separately from the spring element. However, a one-piece or one-piece configuration is also possible.

In an advantageous development of the invention, it can be provided that the spring element and/or the heat-conducting element has a flexural rigidity of 1 nNm/rad to 5,000 nNm/rad. Suitable flexural rigidities are also, for example, 5 nNm/rad to 500 nNm/rad, particularly preferably 10 nNm/rad to 200 nNm/rad.

It can be provided that the at least one spring element and the at least one heat conducting element are dimensioned and designed such that the flexural rigidity of the micromechanical system corresponds to the flexural rigidity of a micromechanical system without the heat conducting element. In order to achieve this, the rigidity of the spring element can be correspondingly reduced in order to compensate for the fact that the heat-conducting element introduces at least a certain flexural rigidity into the system. For example, it may be advisable to reduce the thickness of the spring element, since the rigidity then decreases with the third power, while the thermal resistance increases only linearly.

In an advantageous development of the invention, it can be provided that the spring element and/or the heat-conducting element has a thickness of 100 nm to 1,000 nm, preferably a thickness of 400 nm to 600 nm.

The thicknesses can be selected and matched to one another in such a way that the thermal resistance of the overall system is reduced compared to a system without the heat-conducting element. Suitable simulation models can be used for this.

In a development of the invention, it can be provided that the spring element and/or the heat-conducting element has a thermal resistance of 200 K/W to 20,000 K/W. Suitable thermal resistances are, for example, 500 K/W to 4000 K/W, particularly preferably 500 K/W to 2000 K/W.

Provision can be made for the heat-conducting element to be designed to extend in two or three mutually orthogonal spatial directions.

According to a development of the invention, it can be provided in particular that the heat-conducting element runs at least in sections transversely to the spring element.

A course of the heat conducting element “transverse” to the spring element is preferably, but not necessarily, to be understood as a course of the heat conducting element orthogonal to the spring element. In principle, however, it can be advantageous for the heat-conducting element to run at any angle, that is to say also at a different angle than 90°, relative to the spring element.

In particular, it can also be provided that one or more sections of the at least one heat-conducting element run parallel to the spring element, whereas other sections run at an angle or transversely. Various variants are conceivable in this respect, of which some particularly advantageous geometries are described below.

In an advantageous development of the invention, it can be provided, for example, that the heat-conducting element is designed as a leaf spring with a bend.

Provision can be made for the heat-conducting element to have two attachment sections which accommodate the bend on one side or on both sides. The bend can in particular have a length of 10 μm to 100 μm, preferably about 40 μm. Provision can be made for the attachment section(s) to have a length of 1 μm to 50 μm, preferably approximately 5 μm.

Alternatively or additionally, the heat-conducting element can have one or more kinks or bends.

According to a development of the invention can also be provided that the heat guide element is at least partially formed in a spiral shape. In particular, the heat-conducting element can run in an ascending rotation between the base area and the carrier area.

The rotation of the spiral-shaped section of the heat-conducting element can be, for example, 10° to 180°, preferably 70° to 110°, particularly preferably 89° to 91°.

In an advantageous development of the invention, it can also be provided that the heat-conducting element is designed in the shape of a circular arc at least in sections or forms some other curved course.

The circular arc of the circular arc-shaped section of the heat-conducting element can extend, for example, over 200° to 330°, preferably over 250° to 290°, particularly preferably over 269° to 271°.

In a development of the invention, it can be provided that the micromechanical assembly has two pairs of spring elements, each designed as a leaf spring, in an orthogonal arrangement in order to form a cardanic flexure joint. In particular, in two quadrants of the micromechanical assembly, two of said spring elements can be connected to one another by means of an intermediate plate, with respective heat-conducting elements being able to be arranged in the other two quadrants.

However, other arrangements are also possible within the framework of a micromechanical assembly according to the invention, for example a central arrangement of the heat-conducting elements.

In a preferred development of the invention, the micromirror assembly has a microelectromechanical actuator device for tilting the carrier area relative to the base area (also known as a “tilt manipulator”).

In this way, the orientation of the micromirror or the mirror surface can be changed in cooperation with the at least one spring element and the at least one heat-conducting element. The actuator device can preferably be part of the micromechanical assembly, in particular form a common microelectromechanical system with the at least one spring element and the at least one heat conducting element.

Any type of actuator device can be provided, for example a capacitive or electrostatic actuator device of a MEMS mirror concept according to FIG DE 10 2015 204 874 A1 , the content of which is fully incorporated by reference into the present application text. Alternatively, for example, an actuator device according to WO 2014/140015 A1 for use with the present invention come into consideration, which is why the disclosure of WO 2014/140015 A1 be integrated into the present description. Actuator devices of this type are sufficiently known in the prior art, which is why further details and further examples are omitted here. However, it should be emphasized that the invention is not limited to use with a specific type of actuator.

In addition, the micromirror assembly can also have any other components that are connected to the other components in one piece or monolithically, but possibly also in multiple pieces. For example, a sensor device can be provided which is able to detect the tilt angle of the mirror surface relative to the base area.

At this point it should be mentioned that within the scope of the invention, exactly one heat-conducting element, but optionally also several heat-conducting elements, can be provided, in particular several heat-conducting elements spaced apart from one another and from the spring element or elements.

The invention also relates to a facet arrangement of a facet mirror, having several of the micromirror assemblies according to the above and following statements, which are arranged in relation to one another in such a way that their mirror surfaces together form a segmented facet of the facet mirror and/or which are arranged in relation to one another in such a way that their mirror surfaces form respective facets form the facet mirror.

The individual mirror surfaces or micromirrors can each be tiltable by means of an actuator.

The facet mirror can be formed from individual mirror surfaces or micromirrors, each of which represents an individual facet and has a dimension of approximately 5 mm in the y-direction and 100 mm in the x-direction.

As an alternative to realizing an individual facet by exactly one individual mirror surface or exactly one individual micromirror, each of the facets can also be approximated by groups of smaller mirror surfaces. A facet with dimensions of 5 mm in the y-direction and 100 mm in the x-direction can e.g. B. by means of a 1 x 20 array of individual mirror surfaces with dimensions of 5 mm x 5 mm up to a 10 x 200 array be constructed from individual mirror surfaces with the dimensions 0.5 mm x 0.5 mm.

The facet mirror can have a total of around 100,000 micromirrors, for example. Depending on the size of the individual mirror surfaces, the faceted mirror can also have a different number of individual mirror surfaces. The number of individual mirror surfaces of the faceted mirror is in particular at least 1,000, in particular at least 5,000, in particular at least 10,000. It can be up to 100,000, in particular up to 300,000, in particular up to 500,000, in particular up to 1,000,000.

In an advantageous development of the invention, it can be provided that the base regions of the individual micromirror assemblies are arranged on a common substrate. Each micromirror can then advantageously be tiltable relative to a common reference surface.

The invention also relates to a facet mirror, in particular a field facet mirror or a pupil facet mirror for a projection exposure system, having a facet arrangement according to the statements above and below.

The use of at least one heat-conducting element proposed according to the invention ensures that both the thermal resistance and the spring stiffness of the overall system can be reduced, so that the facet mirror or the micromirror can also be used particularly advantageously under high thermal loads. The proposed facet mirror is therefore particularly advantageously suitable for use with an EUV projection exposure system.

The invention also relates to a projection exposure system for microlithography (in particular an EUV projection exposure system) with an illumination system that has a radiation source and an optical system. The optics have a facet mirror according to the statements above and below, in particular a field facet mirror and/or a pupil facet mirror.

Because the solution according to the invention makes it possible to reduce the thermal resistance between the base region and the carrier region of the mirror surface, the possibility of dissipating heat from the individual micromirrors is significantly improved. The result of this is that, particularly when it is a mirror of an EUV projection exposure system, the formation of defects and the reflection loss, which is increased at higher temperatures, are significantly reduced. A lower mirror temperature also improves the drift stability (thermal deformations) and, with some sensor types, also the measuring accuracy.

It is advantageous if the micromirror assembly is matched to the projection exposure system and designed in such a way that the temperature of the micromirror during operation is less than 200°, preferably less than 100°. This efficiently reduces defect formation and reflection loss at the mirror surface.

According to the invention, the improved heat dissipation makes it possible to increase the performance of the system that radiates onto the mirror, in particular an EUV projection exposure system, compared to the prior art and/or to improve the imaging accuracy of the projection exposure system.

It has been shown that, according to the invention, the thermal resistance between the mirror and the substrate can be reduced by more than 20%, with a simultaneous reduction in the flexural rigidity by more than 25%.

• - eines Basisbereichs;
• - eines von dem Basisbereich beabstandeten Trägerbereichs mit einer von dem Basisbereich abgewandten Spiegelfläche; und
• - einer mikromechanischen Baugruppe, die ein Federelement und ein separates Wärmeleitelement aufweist, wobei das Federelement und das Wärmeleitelement derart voneinander beabstandet und jeweils zwischen dem Basisbereich und dem Trägerbereich angeordnet und ausgebildet werden, dass der Trägerbereich gegenüber dem Basisbereich entlang zumindest zweier Rotationsfreiheitsgrade verkippbar ist.

The invention also relates to a manufacturing method for manufacturing a micromirror assembly of a facet arrangement of a facet mirror, having at least method steps for manufacturing:

• - a base area;
• - A spaced-apart from the base area carrier area with a remote from the base area mirror surface; and
• - a micromechanical assembly that has a spring element and a separate heat-conducting element, the spring element and the heat-conducting element being spaced apart from one another and being arranged and formed between the base area and the carrier area in such a way that the carrier area can be tilted relative to the base area along at least two rotational degrees of freedom.

A tiltable micromirror or a tiltable micromirror arrangement with deformable heat-conducting elements can thus be provided in an advantageous manner.

As part of the manufacturing process, in particular with regard to the selection of the designs of the spring elements and/or the heat conducting elements, provision can first be made for appropriate analytical models to be set up in order to (at least approximately) describe the respective thermal properties and rigidities. Subsequently, it can optionally be provided to reduce free parameters of the model in order to simplify the system. Ultimately, the thermal properties and stiffness can be calculated for a defined parameter space, optimized and checked using subsequent simulation.

• - physikalische Gasphasenabscheidung, insbesondere thermisches Verdampfen, Elektronenstrahlverdampfen, Laserstrahlverdampfen, Lichtbogenverdampfen, Molekularstrahlepitaxie, Sputtern, ionenstrahlgestützte Deposition, ICB-Technik und/oder lonenplattieren; und/oder
• - chemische Gasphasenabscheidung, insbesondere plasmaunterstützte chemische Gasphasenabscheidung, heißdraht-aktivierte Gasphasenabscheidung, chemische Niederdruck-Gasphasenabscheidung und/oder metallorganische chemische Gasphasenabscheidung; und/oder
• - plasma-unterstütztes Ätzen; und/oder
• - reaktives Ionentiefenätzen, insbesondere reaktives Silizium-Ionentiefenätzen.

According to a development of the invention, it can be provided in particular that the micromirror assembly is formed using at least one of the following method steps:

• - physical vapor deposition, in particular thermal vaporization, electron beam vaporization, laser beam vaporization, arc vaporization, molecular beam epitaxy, sputtering, ion beam assisted deposition, ICB technology and/or ion plating; and or
• - chemical vapor deposition, in particular plasma-enhanced chemical vapor deposition, hot-wire-activated vapor deposition, low-pressure chemical vapor deposition and/or metal-organic chemical vapor deposition; and or
• - plasma-assisted etching; and or
• - Deep reactive ion etching, in particular deep reactive silicon ion etching.

The invention also relates to a method for tilting a mirror surface of a facet mirror relative to a base area, which is arranged in a thermally conductive manner on a carrier area, which is connected to the base area via at least one spring element and at least one heat-conducting element of a micromechanical assembly and can be tilted with respect to the base area along at least two rotational degrees of freedom is. A microelectromechanical actuator device is used to tilt the carrier area.

Features that have been described in connection with one of the objects of the invention, namely given by the micromirror assembly according to the invention, the facet arrangement, the facet mirror, the projection exposure system, the manufacturing method or the method for tilting a mirror surface, can also be advantageously implemented for the other objects of the invention . Likewise, advantages that were mentioned in connection with one of the objects of the invention can also be understood in relation to the other objects of the invention.

In addition, it should be noted that terms such as "comprising", "having" or "with" do not exclude any other features or steps. Furthermore, terms such as "a" or "that" which indicate a singular number of steps or features do not exclude a plurality of features or steps - and vice versa.

In a puristic embodiment of the invention, however, it can also be provided that the features introduced in the invention with the terms “comprising”, “having” or “with” are listed exhaustively. Accordingly, one or more listings of features may be considered complete within the scope of the invention, e.g. considered for each claim. The invention can consist exclusively of the features mentioned in claim 1, for example.

It should be mentioned that designations such as “first” or “second” etc. are primarily used for reasons of distinguishing the respective device or method features and are not necessarily intended to indicate that features are mutually dependent or related to one another.

Furthermore, it should be emphasized that the values and parameters described here are deviations or fluctuations of ±10% or less, preferably ±5% or less, more preferably ±1% or less, and very particularly preferably ±0.1% or less of the respectively named Include value or parameter, provided that these deviations are not excluded in the implementation of the invention in practice. The specification of ranges by means of initial and final values also includes all those values and fractions that are enclosed by the range specified in each case, in particular the initial and final values and a respective mean value.

Exemplary embodiments of the invention are described in more detail below with reference to the drawings.

The figures each show preferred exemplary embodiments in which individual features of the present invention are shown in combination with one another. Features of an exemplary embodiment can also be implemented separately from the other features of the same exemplary embodiment and can accordingly easily be combined with features of other exemplary embodiments by a person skilled in the art to form further meaningful combinations and sub-combinations.

Elements with the same function are provided with the same reference symbols in the figures.

• 1 eine EUV-Projektionsbelichtungsanlage im Meridionalschnitt;
• 2 eine Mikrospiegelbaugruppe gemäß einem Ausführungsbeispiel der Erfindung;
• 3 eine mikromechanische Baugruppe mit mehreren Federelementen zur Ausbildung eines Festkörpergelenks für eine erfindungsgemäße Mikrospiegelbaugruppe, gemäß einer ersten Variante;
• 4 eine mikromechanische Baugruppe mit mehreren Federelementen zur Ausbildung eines Festkörpergelenks für eine erfindungsgemäße Mikrospiegelbaugruppe, gemäß einer zweiten Variante;
• 5 eine Mikrospiegelbaugruppe mit einem einzelnen Federelement gemäß dem Stand der Technik;
• 6 eine Mikrospiegelbaugruppe mit einem einzelnen Federelement in Kombination mit einem zusätzlichen Wärmeleitelement gemäß einer Variante der Erfindung in einem nicht ausgelenkten Ruhezustand;
• 7 die Mikrospiegelbaugruppe der 6 in einem ausgelenkten Arbeitszustand;
• 8 eine Mikrospiegelbaugruppe mit einem einzelnen Federelement in Kombination mit einem zusätzlichen Wärmeleitelement gemäß einer weiteren Variante der Erfindung; und
• 9 eine kreisbogenförmige Anordnung eines Wärmeleitelements zwischen dem Basisbereich und dem Trägerbereich.

They show schematically:

• 1 an EUV projection exposure system in the meridional section;
• 2 a micromirror assembly according to an embodiment of the invention;
• 3 a micromechanical assembly with a plurality of spring elements for forming a solid joint for a micromirror assembly according to the invention, according to a first variant;
• 4 a micromechanical assembly with a plurality of spring elements for forming a solid joint for a micromirror assembly according to the invention, according to a second variant;
• 5 a prior art single spring element micromirror assembly;
• 6 a micromirror assembly having a single spring element in combination with an additional thermally conductive element according to a variant of the invention in an undeflected rest state;
• 7 the micromirror assembly 6 in a deflected working condition;
• 8th a micromirror assembly with a single spring element in combination with an additional thermally conductive element according to another variant of the invention; and
• 9 a circular arc-shaped arrangement of a thermally conductive element between the base area and the carrier area.

The following are first with reference to 1 the essential components of an EUV projection exposure system 100 for microlithography are described by way of example. The description of the basic structure of the EUV projection exposure system 100 and its components should not be understood as limiting here.

In addition to a radiation source 102 , an illumination system 101 of the EUV projection exposure system 100 has illumination optics 103 for illuminating an object field 104 in an object plane 105 . In this case, a reticle 106 arranged in the object field 104 is exposed. The reticle 106 is held by a reticle holder 107 . The reticle holder 107 can be displaced via a reticle displacement drive 108, in particular in a scanning direction.

In 1 a Cartesian xyz coordinate system is drawn in for explanation. The x-direction runs perpendicularly into the plane of the drawing. The y-direction is horizontal and the z-direction is vertical. The scan direction is in 1 along the y-direction. The z-direction runs perpendicular to the object plane 105.

The EUV projection exposure system 100 includes projection optics 109. The projection optics 109 are used to image the object field 104 in an image field 110 in an image plane 111. The image plane 111 runs parallel to the object plane 105. Alternatively, there is also an angle other than 0° between the object plane 105 and the image plane 111 is possible.

A structure on the reticle 106 is imaged onto a light-sensitive layer of a wafer 112 arranged in the region of the image field 110 in the image plane 111. The wafer 112 is held by a wafer holder 113. The wafer holder 113 can be displaced via a wafer displacement drive 114, in particular along the y-direction. The displacement of the reticle 106 via the reticle displacement drive 108 on the one hand and the wafer 112 on the other hand via the wafer displacement drive 114 can be synchronized with one another.

The radiation source 102 is an EUV radiation source. The radiation source 102 emits in particular EUV radiation 115, which is also referred to below as useful radiation or illumination radiation. The useful radiation 115 has, in particular, a wavelength in the range between 5 nm and 30 nm a DPP (Gas Discharged Produced Plasma) source. It can also be a synchrotron-based radiation source. The radiation source 102 can be a free-electron laser (FEL).

The illumination radiation 115 emanating from the radiation source 102 is bundled by a collector 116 . The collector 116 can be a collector with one or more ellipsoidal and/or hyperboloidal reflection surfaces. The at least one reflection surface of the collector 116 can be used in grazing incidence ("Grazing Incidence", GI), i.e. with angles of incidence greater than 45°, or in normal incidence ("Normal Incidence", NI), i.e. with angles of incidence smaller than 45° of the illumination radiation 115 are applied. The collector 116 can be structured and/or coated on the one hand to optimize its reflectivity for the useful radiation 115 and on the other hand to suppress stray light.

After the collector 116, the illumination radiation 115 propagates through an intermediate focal point kus in an intermediate focal plane 117. The intermediate focal plane 117 can represent a separation between a radiation source module, comprising the radiation source 102 and the collector 116, and the illumination optics 103.

The illumination optics 103 includes a deflection mirror 118 and a first facet mirror 119 downstream of this in the beam path. The deflection mirror 118 can be a planar deflection mirror or alternatively a mirror with an effect that influences the bundle beyond the pure deflection effect. Alternatively or additionally, the deflection mirror 118 can be designed as a spectral filter, which separates a useful light wavelength of the illumination radiation 115 from stray light of a different wavelength. If the first facet mirror 119 is arranged in a plane of the illumination optics 103 which is optically conjugate to the object plane 105 as a field plane, it is also referred to as a field facet mirror. The first facet mirror 119 includes a multiplicity of individual first facets 120, which are also referred to below as field facets. Of these facets 120 are in the 1 only a few shown as examples.

The first facets 120 can be embodied as macroscopic facets, in particular as rectangular facets or as facets with an arcuate or part-circular edge contour. The first facets 120 can be embodied as planar facets or alternatively as convexly or concavely curved facets.

Like for example from the DE 10 2008 009 600 A1 is known, the first facets 120 themselves can each also be composed of a multiplicity of individual mirrors, in particular a multiplicity of micromirrors. The first facet mirror 119 can be designed in particular as a microelectromechanical system (MEMS system) and can have the micromirror assembly 1 according to the invention, which is also described below.

The illumination radiation 115 runs horizontally between the collector 116 and the deflection mirror 118, ie along the y-direction.

A second facet mirror 121 is arranged downstream of the first facet mirror 119 in the beam path of the illumination optics 103. If the second facet mirror 121 is arranged in a pupil plane of the illumination optics 103, it is also referred to as a pupil facet mirror. The second facet mirror 121 can also be arranged at a distance from a pupil plane of the illumination optics 103 . In this case, the combination of the first facet mirror 119 and the second facet mirror 121 is also referred to as a specular reflector. Specular reflectors are known from US 2006/0132747 A1 , the EP 1 614 008 B1 and the U.S. 6,573,978 .

The second facet mirror 121 includes a plurality of second facets 122. In the case of a pupil facet mirror, the second facets 122 are also referred to as pupil facets.

The second facets 122 can also be macroscopic facets, which can have round, rectangular or hexagonal borders, for example, or alternatively facets composed of micromirrors. In this regard, also on the DE 10 2008 009 600 A1 referred. The pupil facet mirror 121 can also have a micro-mirror assembly 1 according to the present invention.

The second facets 122 can have plane or alternatively convexly or concavely curved reflection surfaces.

The illumination optics 103 thus forms a double-faceted system. This basic principle is also known as the "Fly's Eye Integrator".

It can be advantageous not to arrange the second facet mirror 121 exactly in a plane which is optically conjugate to a pupil plane of the projection optics 109 .

The individual first facets 120 are imaged in the object field 104 with the aid of the second facet mirror 121 . The second facet mirror 121 is the last beam-forming mirror or actually the last mirror for the illumination radiation 115 in the beam path in front of the object field 104.

In a further embodiment of the illumination optics 103 that is not shown, transmission optics can be arranged in the beam path between the second facet mirror 121 and the object field 104 , which particularly contribute to the imaging of the first facets 120 in the object field 104 . The transmission optics can have exactly one mirror, but alternatively also have two or more mirrors, which are arranged one behind the other in the beam path of the illumination optics 103 . The transmission optics can in particular comprise one or two mirrors for normal incidence (NI mirror, "normal incidence" mirror) and/or one or two mirrors for grazing incidence (GI mirror, "gracing incidence" mirror).

The illumination optics 103 has the version in which 1 shown, exactly three mirrors after the collector 116, namely the deflection mirror 118, the field facet mirror 119 and the pupil facet mirror 121.

In a further embodiment of the illumination optics 103, the deflection mirror 118 can also be omitted, so that the illumination optics 103 can then have exactly two mirrors downstream of the collector 116, namely the first facet mirror 119 and the second facet mirror 121.

The imaging of the first facets 120 by means of the second facets 122 or with the second facets 122 and transmission optics in the object plane 105 is generally only an approximate imaging.

The projection optics 109 includes a plurality of mirrors Mi, which are numbered consecutively according to their arrangement in the beam path of the EUV projection exposure system 100 .

At the in the 1 example shown, the projection optics 109 includes six mirrors M1 to M6. Alternatives with four, eight, ten, twelve or another number of mirrors Mi are also possible. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 115. The projection optics 109 are doubly obscured optics. The projection optics 109 has an image-side numerical aperture which is greater than 0.5 and which can also be greater than 0.6 and which can be 0.7 or 0.75, for example.

Reflection surfaces of the mirrors Mi can be designed as free-form surfaces without an axis of rotational symmetry. Alternatively, the reflection surfaces of the mirrors Mi can be designed as aspherical surfaces with exactly one axis of rotational symmetry of the reflection surface shape. Just like the mirrors of the illumination optics 103, the mirrors Mi can have highly reflective coatings for the illumination radiation 115. These coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon.

The projection optics 109 has a large object image offset in the y-direction between a y-coordinate of a center of the object field 104 and a y-coordinate of the center of the image field 110. This object-image offset in the y-direction can be about as large like a z-distance between the object plane 105 and the image plane 111.

The projection optics 109 can in particular be anamorphic. In particular, it has different image scales βx, βy in the x and y directions. The two image scales βx, βy of the projection optics 109 are preferably at (βx, βy)=(+/−0.25, +/-0.125). A positive image scale β means an image without image reversal. A negative sign for the imaging scale β means imaging with image inversion.

The projection optics 109 thus leads to a reduction in the ratio 4:1 in the x-direction, ie in the direction perpendicular to the scanning direction.

The projection optics 109 lead to a reduction of 8:1 in the y-direction, ie in the scanning direction.

Other imaging scales are also possible. Image scales with the same sign and absolutely the same in the x and y directions, for example with absolute values of 0.125 or 0.25, are also possible.

The number of intermediate image planes in the x-direction and in the y-direction in the beam path between the object field 104 and the image field 110 can be the same or, depending on the design of the projection optics 109, can be different. Examples of projection optics with different numbers of such intermediate images in the x and y directions are known from U.S. 2018/0074303 A1 .

In each case one of the pupil facets 122 is assigned to precisely one of the field facets 120 in order to form a respective illumination channel for illuminating the object field 104 . In particular, this can result in illumination based on Köhler's principle. The far field is broken down into a large number of object fields 104 with the aid of the field facets 120 . The field facets 120 generate a plurality of images of the intermediate focus on the pupil facets 122 assigned to them.

The field facets 120 are each imaged onto the reticle 106 by an associated pupil facet 122 in a superimposed manner in order to illuminate the object field 104 . In particular, the illumination of the object field 104 is as homogeneous as possible. It preferably has a uniformity error of less than 2%. Field uniformity can be achieved by superimposing different illumination channels.

The illumination of the entrance pupil of the projection optics 109 can be geometrically defined by an arrangement of the pupil facets. By selecting the illumination channels, in particular the subset of the pupil facets that guide light, the intensity distribution in the entrance the projection optics 109 can be adjusted. This intensity distribution is also referred to as an illumination setting.

A likewise preferred pupil uniformity in the area of defined illuminated sections of an illumination pupil of the illumination optics 103 can be achieved by redistributing the illumination channels.

Further aspects and details of the illumination of the object field 104 and in particular the entrance pupil of the projection optics 109 are described below.

The projection optics 109 can in particular have a homocentric entrance pupil. This can be accessible. It can also be inaccessible.

The entrance pupil of the projection optics 109 cannot regularly be illuminated exactly with the pupil facet mirror 121 . When imaging the projection optics 109, which telecentrically images the center of the pupil facet mirror 121 onto the wafer 112, the aperture rays often do not intersect at a single point. However, a surface can be found in which the distance between the aperture rays, which is determined in pairs, is minimal. This surface represents the entrance pupil or a surface conjugate to it in position space. In particular, this surface shows a finite curvature.

The projection optics 109 may have different positions of the entrance pupil for the tangential and for the sagittal beam path. In this case, an imaging element, in particular an optical component of the transmission optics, should be provided between the second facet mirror 121 and the reticle 106 . With the help of this optical component, the different positions of the tangential entrance pupil and the sagittal entrance pupil can be taken into account.

At the in the 1 In the arrangement of the components of the illumination optics 103 shown, the pupil facet mirror 121 is arranged in a surface conjugate to the entrance pupil of the projection optics 109 . The field facet mirror 119 is arranged tilted to the object plane 105 . The first facet mirror 119 is tilted relative to an arrangement plane that is defined by the deflection mirror 118 .

The first facet mirror 119 is tilted relative to an arrangement plane that is defined by the second facet mirror 121 .

The present invention is suitable in particular for EUV projection exposure systems, in particular for EUV projection exposure systems such as are exemplified in FIG 1 shown. However, the use of the invention is not limited to use in projection exposure systems 100, in particular not with the structure described. Furthermore, the invention and the following exemplary embodiments are not to be understood as being restricted to a specific design. The following figures represent the invention only by way of example and in a highly schematic manner.

In 2 1 shows a perspective but highly schematic illustration of a micromirror assembly 1 of a facet arrangement 2 of a facet mirror according to a first exemplary embodiment of the invention. The micromirror assembly 1 can in particular be part of the above-described field facet mirror 119 and/or pupil facet mirror 121 of the EUV projection exposure system 100 .

The micromirror assembly 1 includes a carrier area 3 with a mirror surface 4 or a “micromirror”. The mirror surface 4 can in particular be an individual facet 120, 122 of a facet mirror 119, 121 or one of several mirror surfaces of an individual facet 120, 122 of a facet mirror 119, 121. In the exemplary embodiment, the carrier region 3 forms the mirror body, on the front side of which the reflection surface, that is to say the mirror surface 4, is formed. The mirror surface 4 can be formed by a multi-layer structure and can preferably be radiation-reflecting for EUV radiation.

The micromirror assembly 1 has a base portion 5 spaced from the support portion 3 . The base area 5 is part of a substrate and can also be referred to as a base plate.

The carrier area 3 together with the mirror surface 4 can be tilted relative to the base area 5 along at least two rotational degrees of freedom R _1,2 , for which one in 2 indicated as a black box, microelectromechanical actuator device 6 is used. The actuator device 6 is part of a micromechanical assembly 7, which also has the spring elements 8 described below, which together with separate heat-conducting elements 9, also described below, form an articulated connection, so that the carrier region 3 with the mirror surface 4 can be tilted accordingly by the actuator device 6 . In 3 the mirror surface 4 is shown in a tilted state by way of example.

To detect the pivoting position of the mirror surface 4, a sensor device (not specified) can be provided—suitable implementations are known in the prior art.

The following are with reference to the 3 and 4 two exemplary variants of a cardanic solid-state joint of the micromechanical assembly 7 of a micromirror assembly 1 according to the invention, which are not limiting for the invention, are described in more detail, with reference being made to FIG DE 10 2015 204 874 A1 be referred.

According to the 3 illustrated variant, the solid joint is formed by means of two torsion spring elements and therefore includes two spring elements 8 or torsion springs. The two spring elements 8 are designed in one piece and are aligned perpendicular to one another. The spring elements 8 extend in the direction of a respective tilting axis and are connected to the base area 5 on the one hand and to the carrier area 3 on the other hand via corresponding connecting blocks 12 which are each arranged at an end area of the corresponding spring element 8 .

The spring elements 8 of the flexure joint have a T-shaped profile in the area of the legs of the cross-shaped structure adjoining the central area and are thereby stiffened, in particular with regard to deflections in the direction of the surface normal N. A targeted design of the stiffening element 13 allows the mechanical and/or thermal properties of the flexure joint or the micromechanical assembly 7 in a targeted manner. The stiffening elements 13 can in particular serve to influence the rigidity in the actuator plane.

The micromechanical assembly 7 is also used to dissipate heat from the mirror surface 4 or from the carrier area 3, which according to the invention by in the 3 and 4 not shown heat-conducting elements 9 (or by at least one additional heat-conducting element 9) should be improved. The at least one heat-conducting element 9 (see, for example, 6 ) can go to the in the 3 and 4 illustrated spring elements 8 form an idler joint, preferably with less rigidity, so that the at least one heat conducting element 9 does not affect the mechanical properties of the micromechanical assembly 7 through the heat conducting elements 9 in a disruptive manner, but the heat dissipation from the mirror surface 4 is increased. How an advantageous combination of spring elements 8 and heat-conducting elements 9 can result is explained in detail below.

At the in 4 In the illustrated variant of the flexure joint, two pairs of spring elements 8 or two pairs of spiral springs are provided instead of the torsion springs. In this variant, too, the flexure joint has a high degree of rigidity in the horizontal degrees of freedom. At the in 4 The illustrated variant of the flexure joint is a cardanic flexure joint with orthogonally arranged, horizontal spring elements 8 designed as leaf springs. For connection to the base area 5 and the support area 3, connection blocks 12 are provided again, which in the exemplary embodiment of FIG 4 are each elongated, rod-shaped. A separating slot is provided between each two of the connecting blocks 12; the flexure joint is thus formed in two parts. Again, a combination with at least one heat conducting element 9 is provided in order to dissipate heat from the in 4 to improve the mirror surface 4, not shown, to the base region 5, also not shown. The heat conducting elements 9 are in 4 not shown, but can be provided in particular in the quadrants in which no intermediate plate 14 is formed. Alternatively, provision can also be made for the spring elements 8 to be shifted to the outside, so that the free space thus created in the center of the assembly 7 can be used for the arrangement of the heat-conducting elements 9 .

Based on 6 and 7 shall be compared with the prior art in accordance with 5 a highly simplified example of a micromechanical assembly 7 for a micromirror assembly 1 is illustrated. In a similar way, more complex solid joints, such as in the 2 until 4 shown, are expanded according to the invention with at least one heat-conducting element 9.

The thermal resistance for the in 5 Micromechanical assembly 7 shown is solely due to the individual spring element 8 (leaf spring), whereas the thermal resistance for in the 6 and 7 illustrated micromechanical assembly 7 results from the combination of a spring element 8 (leaf spring) and a thermally conductive element 9, which has a section running transversely to the spring element 8 or a bend 15. The thermal resistance is correspondingly reduced in the micromechanical assembly 7 according to the invention.

Nevertheless, it must be taken into account that the flexural rigidity for the micromechanical assembly 7 according to 5 is also only due to the spring element 8, whereas the heat conducting element 9 in the 6 and 7 the Stiffness can basically increase. It is proposed that the rigidities of the two micromechanical assemblies 7 ( 5 and 6 /7) to be interpreted in the same way. Because of the addition of the heat conducting element 9, the rigidity of the spring element 8 should therefore be reduced to such an extent that the overall rigidity of the micromechanical assembly 7 remains unchanged. For this purpose, the thickness of the spring element 8 can preferably be reduced, since this reduces the rigidity to the third power, with only a linear increase in the thermal resistance.

Another example of a micromechanical assembly 7 according to the invention is shown in 8th shown. The variant is similar to that in the 6 and 7 The configuration already described in detail, however, additionally has respective horizontal sections 17 of the heat-conducting element 9 between the attachment sections 16 and the bend 15, which can also be dispensed with if necessary.

In principle, different geometries can be provided for the heat-conducting element 9, which are well suited to introducing only a small amount of additional rigidity into the system. An example is in 9 a heat-conducting element 9 running in the form of a circular arc between the base region 5 and the carrier region 3 is indicated. The other components of the micromirror assembly 1 are not shown for the sake of simplicity.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was 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.

Patent Literature Cited

• DE 102015204874 A1 [0009, 0066, 0144]
• WO 2014140015 A1 [0066]
• DE 102008009600 A1 [0106, 0110]
• US20060132747A1[0108]
• EP 1614008 B1 [0108]
• US6573978 [0108]
• US20180074303 A1[0127]

Claims (29)

Micromirror assembly (1) of a facet arrangement (2) of a facet mirror (119, 121), having a base area (5), a carrier area (3) at a distance from the base area (5) and having a mirror surface (4) facing away from the base area (5), and a micromechanical assembly (7) with a spring element (8) and a separate heat-conducting element (9), the spring element (8) and the heat-conducting element (9) being spaced apart from one another in each case so arranged between the base region (5) and the carrier region (3). and are designed such that the carrier area (3) can be tilted relative to the base area (5) along at least two rotational degrees of freedom (R _1,2 ). Micromirror assembly (1) according to claim 1 , characterized in that the base area (5), the carrier area (3) and the micromechanical assembly (7) are produced in a common method for the production of microstructures. Micromirror assembly (1) according to claim 1 or 2 , characterized in that the micro-mirror assembly (1) is monolithic. Micromirror assembly (1) according to one of Claims 1 until 3 , characterized in that the mirror surface (4) has a spatial extent of less than 10 mm in each direction, preferably less than 6 mm, particularly preferably less than 5 mm, very particularly preferably less than 3 mm, for example less than 1mm. Micromirror assembly (1) according to one of Claims 1 until 4 , characterized in that one or more components of the micromechanical assembly (7), in particular the spring element (8) and / or the heat conducting element (9), are formed from polycrystalline silicon and / or monocrystalline silicon. Micromirror assembly (1) according to one of Claims 1 until 5 , characterized in that one or more components of the micromechanical assembly (7), in particular the spring element (8) and / or the heat conducting element (9), have a coating which has silicon carbide, gold, silver, aluminum and / or copper. Micromirror assembly (1) according to claim 6 , characterized in that the coating has a layer thickness of 10 nm to 200 nm. Micromirror assembly (1) according to one of Claims 1 until 7 , characterized in that the spring element (8) is designed as a leaf spring. Micromirror assembly (1) according to one of Claims 1 until 8th , characterized in that the thermally conductive element (9) has a lower flexural rigidity than the spring element (8) with regard to the rotational degrees of freedom (R _1,2 ) by which the carrier area (3) can be tilted relative to the base area (5), preferably by at least one a factor of 2, particularly preferably at least a factor of 4, very particularly preferably at least a factor of 10 lower flexural rigidity than the heat-conducting element (9). Micromirror assembly (1) according to one of Claims 1 until 9 , characterized in that the spring element (8) and/or the heat-conducting element (9) has a flexural rigidity of 1 nNm/rad to 5,000 nNm/rad, preferably 5 nNm/rad to 500 nNm/rad, particularly preferably 10 nNm/rad rad up to 200 Nm/rad. Micromirror assembly (1) according to one of Claims 1 until 10 , characterized in that the spring element (8) and / or the heat conducting element (9) has a thickness of 100 nm to 1000 nm, preferably a thickness of 400 nm to 600 nm. Micromirror assembly (1) according to one of Claims 1 until 11 , characterized in that the spring element (8) and/or the heat-conducting element (9) has a thermal resistance of 200 K/W to 20,000 K/W, preferably of 500 K/W to 4,000 K/W, particularly preferably of 500 K/W W up to 2,000 K/W. Micromirror assembly (1) according to one of Claims 1 until 12 , characterized in that the heat conducting element (9) runs at least in sections transversely to the spring element (8). Micromirror assembly (1) according to Claim 13 , characterized in that the heat-conducting element (9) is designed as a leaf spring with a bend (15) and/or with a kink. Micromirror assembly (1) according to Claim 14 , characterized in that the bend (15) has a length of 10 µm to 100 µm. Micromirror assembly (1) according to one of Claims 1 until 15 , characterized in that the heat conducting element (9) is at least partially spirally formed and in an ascending rotation between the base area (5) and the carrier area (3). Micromirror assembly (1) according to Claim 16 , characterized in that the rotation of the spiral-shaped section of the heat-conducting element (9) is 10° to 180°, preferably 70° to 110°, particularly preferably 89° to 91°. Micromirror assembly (1) according to one of Claims 1 until 17 , characterized in that the heat conducting element (9) is at least partially formed in the shape of a circular arc. Micromirror assembly (1) according to Claim 18 , characterized in that the circular arc of the circular arc-shaped section of the heat-conducting element (9) extends over 200° to 330°, preferably over 250° to 290°, particularly preferably over 269° to 271°. Micromirror assembly (1) according to one of Claims 1 until 19 , characterized in that the micromechanical subassembly (7) has two pairs of spring elements (8), each designed as a leaf spring, in an orthogonal arrangement in order to form a cardanic flexure joint, with two of the spring elements (8) in each case in two quadrants of the micromechanical subassembly (7) are connected to one another by means of an intermediate plate (14), and wherein respective heat-conducting elements (9) are arranged in the other two quadrants. Micromirror assembly (1) according to one of Claims 1 until 20 , characterized by a microelectromechanical actuator device (6) for tilting the carrier area (3) relative to the base area (5). Facet arrangement (2) of a facet mirror (119, 121), having a plurality of micro-mirror assemblies (1) according to one of Claims 1 until 21 , which are arranged relative to each other such that their mirror surfaces (4) together form a segmented facet (120, 122) of the facet mirror (119, 121) and/or respective facets (120, 122) of the facet mirror (119, 121). Facet arrangement (2) after Claim 22 , characterized in that the base regions (5) of the individual micromirror assemblies (1) are arranged on a common substrate. Facet mirror, in particular field facet mirror (119) or pupil facet mirror (121) for a projection exposure system (100), having a facet arrangement (2) according to Claim 22 or 23 . Projection exposure system (100) for microlithography, with an illumination system (101) having a radiation source (102) and optics (103, 109), wherein the optics (103, 109) have a facet mirror (119, 121) according to Claim 24 has, in particular a field facet mirror (119) and/or a pupil facet mirror (121). Manufacturing method for manufacturing a micromirror assembly (1) of a facet arrangement (2) of a facet mirror (119, 121), having at least method steps for manufacturing: - a base region (5); - A carrier region (3) spaced from the base region (5) and having a mirror surface (4) facing away from the base region (5); and - a micromechanical assembly (7) which has a spring element (8) and a separate heat-conducting element (9), the spring element (8) and the heat-conducting element (9) being spaced apart from one another and each between the base area (5) and the carrier area (3) are arranged and designed such that the carrier area (3) can be tilted relative to the base area (5) along at least two rotational degrees of freedom (R _1,2 ). manufacturing process Claim 26 , characterized in that the micromirror assembly (1) is formed using at least one of the following process steps: - physical vapor deposition, in particular thermal evaporation, electron beam evaporation, laser beam evaporation, arc evaporation, molecular beam epitaxy, sputtering, ion beam assisted deposition, ICB technology and/or ion plating; and/or chemical vapor deposition, in particular plasma-enhanced chemical vapor deposition, hot-wire-activated vapor deposition, low-pressure chemical vapor deposition and/or metal-organic chemical vapor deposition; and/or - plasma-assisted etching; and/or deep reactive ion etching, in particular deep reactive silicon ion etching. manufacturing process Claim 26 or 27 , characterized in that the micro-mirror assembly (1) is formed using at least one application process step, preferably monolithic. Method for tilting a mirror surface (4) of a facet mirror (119, 121) relative to a base area (5), which is arranged in a thermally conductive manner on a carrier area (3) which has a spring element (8) and a heat-conducting element (9) of a micromechanical assembly (7) connected to the base area (5) and to the base area rich (5) along at least two rotational degrees of freedom (R _1.2 ) can be tilted, a microelectromechanical actuator device (6) being used to tilt the carrier area (3).

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