Patent Description:
Microlithography is used for producing microstructured components, for example integrated circuits. The microlithography process is performed using a lithography apparatus, which has an illumination system and a projection system. The image of a mask (reticle) illuminated by means of the illumination system is in this case projected by means of the projection system onto a substrate (for example a silicon wafer) which is coated with a light-sensitive layer (photoresist) and arranged in the image plane of the projection system, in order to transfer the mask structure to the light-sensitive coating of the substrate.

Driven by the desire for ever smaller structures in the production of integrated circuits, currently under development are EUV lithography apparatuses that use light with a wavelength in the range from <NUM> to <NUM>, in particular <NUM>. In the case of such EUV lithography apparatuses, because of the high absorption of light of this wavelength by most materials, reflective optical units, that is to say mirrors, have to be used instead of - as previously - refractive optical units, that is to say lens elements.

An EUV lithography apparatus as explained above comprises components having a cooling circuit, for example for cooling the respective component with water, or a purging circuit, for example for purging the respective component with a purge gas, in particular with an inert gas. A component of this type can be a so-called actuation sensor unit, for example, with the aid of which facets of a facet mirror, for example of a field facet mirror or of a pupil facet mirror, can be deflected. In this case, a so-called actuation sensor package is assigned to each facet for the purpose of deflecting the facets. The actuation sensor packages should be sealed in a fluid-tight manner vis-à-vis a main body or frame of the actuation sensor unit.

For sealing purposes, O-rings or sealing mats can be used as seals. In order to maintain the sealing function during operation and over the lifetime, the seal can be clamped onto the respective actuation sensor package by means of prestress or in a manner supported in the pressure direction. A centring of the seal can be obtained as a result. In this case, it should be taken into consideration that the seal requires a yielding volume for the purpose of pressing it. Said yielding volume can be created by keeping enough space available between an inner contour of the respective seal and the actuation sensor package. However, this space is in turn disadvantageous with regard to a good centring of the seal. For instance, <CIT> discloses a facet mirror comprising a multiplicity of sealing rings.

Against this background, it is an object of the present invention to provide an improved sealing device.

In accordance with claim <NUM>, a sealing device for sealing a first component part of a lithography apparatus vis-à-vis a multiplicity of second component parts of the lithography apparatus is proposed. The sealing device comprises a multiplicity of sealing rings, and a multiplicity of connection locations, wherein the sealing rings are integrally connected to one another with the aid of the connection locations.

By virtue of the fact that the sealing rings are connected to one another with the aid of the connection locations, the mounting of the sealing device is simplified compared to a sealing device without such connection locations.

The sealing device can also be referred to as a sealing mat. Preferably, a multiplicity of sealing rings is provided which form a two-dimensional pattern or grid. That is to say that the sealing rings are arranged in particular in the shape of a grid or in the shape of a pattern. A plurality of connection locations, for example four, are assigned to each sealing ring. The connection locations can also be referred to as contact locations. In accordance with the invention, the sealing rings are connected to one another integrally, in particular materially in one piece, with the aid of the connection locations. "Integrally" means in the present case that the sealing rings together form a common component part, namely the sealing device. "Materially in one piece" means here that the sealing device is produced from the same material throughout. Preferably, the sealing device is produced from a plastics material. By way of example, a perfluoro rubber (FFKM) can be used as suitable material. The sealing device can be cut out from a sheet or film of a suitable plastics material with the aid of a laser, for example.

In accordance with one embodiment, the connection locations each comprise a yielding volume for pressing the respective sealing ring between the first component part and one of the second component parts.

By virtue of the fact that the yielding volume is provided, it is possible for the respective sealing ring always to be sufficiently pressed, with the result that leaks during mounting and also over the service life of the lithography apparatus can be prevented or at least significantly reduced. The yielding volume can be provided between an inner contour of the respective sealing ring and a second component part received in the inner contour. However, the yielding volume can also be provided directly in or at the respective connection location, for example in the form of a cutout, a groove, a hole or the like. All that is relevant here is that material of the sealing ring is pressed into the yielding volume during the pressing of the respective sealing ring. The abovementioned inner contour of the sealing ring can have an arbitrary shape. The inner contour can be circular, oval, triangular, polygonal or the like. Furthermore, the inner contour - as will be explained below - can also be trefoiled. The yielding volume is provided in particular in or at the sealing device itself.

In accordance with a further embodiment, each sealing ring comprises an inner contour, in each of which a second component part is able to be received at least in sections, and wherein the yielding volume is formed by virtue of the inner contour widening at the connection locations.

The fact that the inner contour "widens" means in the present case that the inner contour, at least in an unpressed state of the respective sealing ring, does not bear against the corresponding second component part and thus stands away from the second component part, in particular. By virtue of the fact that the inner contour widens at the connection locations, a sufficiently large yielding volume for the pressing of the respective sealing ring can be provided at the connection locations.

In accordance with a further embodiment, the inner contour comprises a connection radius at the connection locations, wherein the inner contour comprises an intermediate radius in each case between two adjacent connection locations, and wherein the intermediate radius and the connection radius differ from one another in terms of their absolute value in such a way that the inner contour widens at the connection locations and narrows between two adjacent connection locations.

By virtue of the fact that the inner contour narrows between two adjacent connection locations, a centring of the sealing rings at the respective intermediate radius is made possible. Thus, with the aid of the widening and the narrowing, it is possible simultaneously to ensure a sufficiently large yielding volume for the pressing of the sealing rings and a centring of the sealing rings at the second component parts.

In accordance with one preferred embodiment of the sealing device, the latter comprises a multiplicity of sealing rings, a multiplicity of connection locations, wherein the sealing rings are connected to one another with the aid of the connection locations, wherein each sealing ring comprises an inner contour, in each of which a second component part is able to be received at least in sections, wherein the inner contour comprises a connection radius at the connection locations, wherein the inner contour comprises an intermediate radius in each case between two adjacent connection locations, and wherein the intermediate radius and the connection radius differ from one another in terms of their absolute value in such a way that the inner contour widens at the connection locations and narrows between two adjacent connection locations.

The inner contour is composed of a plurality of radii, in particular. That is to say that the inner contour is preferably not circular. The inner contour can also have any other geometry, as mentioned above. In the region of the connection locations, the inner contour has a widening or broadening and, in the region between the connection locations, the inner contour has a narrowing, constriction or restriction. This results in a trefoiled or trefoil-like geometry of the inner contour, deviating from the circular shape. The inner contour can therefore be referred to as "trefoiled" or "trefoil-like". The sealing device is positioned in particular between a sealing surface of the first component part and a sealing surface of the second component part and effects fluid-tight sealing vis-à-vis them.

The fact that the second component part is "able to be received" in the inner contour should be understood in the present case to mean that a respective sealing ring can be put onto the second component part, or vice versa. In this case, the second component part preferably has a circular-cylindrical base section, at which the sealing ring is centred with the aid of the intermediate radius.

Preferably, as mentioned above, four connection locations are provided. Accordingly, the inner contour also has four times the connection radius and four times the intermediate radius. Accordingly, there are, in particular, also four pairs of adjacent connection locations, between each of which a connection radius is provided. The radii transition into one another, such that the inner contour has no shoulders, but rather a curved shape.

The fact that the intermediate radius and the connection radius "differ" from one another should be understood to mean, in particular, that the intermediate radius is greater than the connection radius, or vice versa. A centre point of the connection radius can be offset relative to a centre point of the intermediate radius in such a way that the condition that the inner contour widens at the connection locations and narrows between two adjacent connection locations is met both if the connection radius is greater than the intermediate radius and if the connection radius is less than the intermediate radius.

In accordance with a further embodiment, the intermediate radius is greater than the connection radius.

By way of example, the connection radius is approximately <NUM>. The intermediate radius can be approximately <NUM> to <NUM>.

In accordance with a further embodiment, the inner contour comprises a first intermediate radius and a second intermediate radius, wherein the first intermediate radius and the second intermediate radius are equal in magnitude or have different magnitudes.

Preferably, the first intermediate radius is greater than the second intermediate radius. Alternatively, the first intermediate radius can also be less than the second intermediate radius. With the aid of the different intermediate radii, it is possible, if the connection locations are positioned in a manner spaced apart from one another at different azimuth angles in an azimuth direction or circumferential direction, to take account of the fact that a shortening of the sealing ring by the factor of azimuth angle/<NUM>° is to be produced between two connection locations in order, during the mounting of the sealing device, to prevent the connection locations from moving azimuthally, which could otherwise lead to warpage of the sealing device. For the case where the azimuth angles are equal in magnitude, the first intermediate radius and the second intermediate radius are preferably also equal in magnitude. Preferably, the connection locations are constructed in each case symmetrically with respect to a line of symmetry assigned to the respective connection location. The azimuth angles are measured between the lines of symmetry of the connection locations. A respective centre point of the connection radius lies on the line of symmetry of that connection location to which the connection radius is assigned.

In accordance with a further embodiment, the second intermediate radius has a bigger magnitude than the first intermediate radius.

Alternatively, the second intermediate radius can also have a smaller magnitude than the first intermediate radius.

In accordance with a further embodiment, two adjacent connection locations between which the first intermediate radius is provided and two adjacent connection locations between which the second intermediate radius is provided are arranged in a manner spaced apart at the same distance or at different distances from one another.

Preferably, the connection locations are positioned in a manner spaced apart from one another non-uniformly as viewed in the circumferential direction. That is to say that different azimuth angles are provided between the connection locations. In this case, the first intermediate radius is positioned between a pair of connection locations between which a smaller azimuth angle is provided. The second intermediate radius is provided between a pair of connection locations between which a larger azimuth angle is provided. For the case where the azimuth angles are equal in magnitude, the connection locations are also arranged in a manner spaced apart at an equal distance from one another.

In accordance with a further embodiment, a centre point of the intermediate radius is arranged offset relative to a centre point of the connection radius.

Preferably, the sealing ring comprises a first plane of symmetry and a second plane of symmetry, with respect to which the sealing ring is constructed symmetrically. The planes of symmetry are positioned perpendicularly to one another, in particular. The centre point of the intermediate radius is positioned eccentrically. The centre point of the connection radius is also positioned eccentrically. As mentioned above, the centre point of the connection radius lies on the respective line of symmetry of the connection location.

In accordance with a further embodiment, a centre point of the first intermediate radius is arranged offset relative to the centre point of the connection radius in an x-direction and a y-direction of the sealing ring, wherein a centre point of the second intermediate radius is arranged offset relative to the centre point of the connection radius in the x-direction and in the y-direction of the sealing ring.

In particular, a coordinate system having a first spatial direction or x-direction, a second spatial direction or y-direction and a third spatial direction or z-direction is assigned to the sealing ring. The spatial directions are positioned perpendicularly to one another. The first plane of symmetry is spanned by the y-direction and the z-direction, in particular. The second plane of symmetry is spanned by the x-direction and the z-direction, in particular. The inner contour runs in particular as two-dimensional geometry in the x-direction and the y-direction. The centre point of the first intermediate radius is positioned offset relative to the centre point of the connection radius in the x-direction and the y-direction in particular in such a way that the inner contour experiences a constriction in the region of the first intermediate radius, even though the first intermediate radius is greater than the connection radius. In particular, the centre point of the second intermediate radius is positioned offset relative to the centre point of the connection radius in the x-direction and in the y-direction in such a way that the inner contour experiences a constriction in the region of the second intermediate radius, even though the second intermediate radius is preferably greater than the connection radius.

In accordance with a further embodiment, centre points of two first intermediate radii are arranged in a manner spaced apart from one another by a first distance in the y-direction, wherein centre points of two second intermediate radii are arranged in a manner spaced apart from one another by a second distance in the x-direction, and wherein the first distance and the second distance are equal in magnitude or have different magnitudes.

In particular, the centre points of the two first intermediate radii are positioned in the first plane of symmetry and outside the second plane of symmetry. Preferably, the centre points are positioned mirror-symmetrically with respect to the second plane of symmetry. In particular, the centre points of the two second intermediate radii are positioned in the second plane of symmetry and outside the first plane of symmetry. Preferably, the centre points of the second intermediate radii are positioned mirror-symmetrically with respect to the first plane of symmetry. For the case where the azimuth angles are equal in magnitude, the first distance and the second distance are preferably equal in magnitude.

In accordance with a further embodiment, the first intermediate radii and the second intermediate radii are arranged alternating along the inner contour.

This means that seen along the inner contour, each first intermediate radius is arranged between two second intermediate radii and vice versa. The two first intermediate radii are arranged vis-á-vis or with a peripheral angle of <NUM>°. The same can be valid for the second intermediate radii.

In accordance with a further embodiment, the inner contour comprises a transition radius, wherein the intermediate radius transitions into the connection radius with the aid of the transition radius.

This ensures a continuously variable transition from the intermediate radius to the transition radius. Preferably, the transition radius is less than the intermediate radius and the connection radius.

In accordance with a further embodiment, two yielding volumes are provided per connection location, wherein a connection web of the connection location is provided between the two yielding volumes, and wherein the connection web connects adjacent sealing rings to one another.

In particular, the connection web connects the sealing rings to one another integrally, in particular materially in one piece.

In accordance with a further embodiment, the yielding volume is a groove which completely penetrates through a wall thickness of the sealing device or which extends only to a defined depth into the wall thickness.

For the case where the groove penetrates through the wall thickness only to the defined depth, the groove can be rectangular or rounded in cross section. If the groove does not completely penetrate through the wall thickness, said groove can also extend through the connection web. The groove can comprise sidewalls running parallel to one another. The sidewalls can also be positioned obliquely with respect to one another, such that the groove is wedge-shaped.

In accordance with a further embodiment, the yielding volume comprises a multiplicity of holes which completely penetrate through a wall thickness of the sealing device or which extend only to a defined depth into the wall thickness.

The holes can all have the same diameter or different diameters. The holes can be arranged in a manner spaced apart from one another uniformly or non-uniformly. The holes can be arranged in one row or a plurality of rows.

Furthermore, a component for a lithography apparatus is proposed. The component comprises a first component part, a multiplicity of second component parts which are received at least in sections in the first component part, and a sealing device of this type.

By way of example, the component can be part of a beam shaping and illumination system or of a projection system of the lithography apparatus. The component can be a so-called Actuation Sensor Unit (ASU), for example, with the aid of which facets of a facet mirror, for example of a field facet mirror or of a pupil facet mirror, can be deflected. Such a facet mirror having deflectable facets can be part of the beam shaping and illumination system, for example. The first component part can be for example a main body or frame of the component. The first component part can comprise a cooling system for cooling the component, in particular the second component parts. The cooling system can be formed with the aid of cooling channels provided in the first component part. The second component part can be an Actuation Sensor Package (ASP), for example, which is suitable for deflecting a facet of a facet mirror as mentioned above. The second component parts can have a circular-cylindrical geometry at least in sections. With the aid of the sealing device, the second component parts are sealed vis-à-vis the first component part in order to seal the cooling system with respect to surroundings of the component.

In accordance with one embodiment, the sealing rings are pressed in each case between the first component part and one of the second component parts in such a way that a respective yielding volume of the sealing device is at least partly filled with material of the respective sealing ring.

During the pressing of the sealing ring, the latter is pressed at least partly into the yielding volume. A permanent safeguard against leaks is achieved as a result.

In accordance with one preferred embodiment, the component comprises a first component part, a multiplicity of second component parts which are received in the first component part at least in sections, a sealing device as explained above, wherein the inner contour, for the purpose of centring the respective sealing ring at one of the second component parts, bears against the second component part with the intermediate radius, and wherein the inner contour, for the purpose of providing a yielding volume between the inner contour and the second component part, stands away from the second component part at the connection radius.

The fact that the inner contour "stands away" from the second component part at the connection radius for the purpose of providing the yielding volume should be understood to mean, in particular, that the inner contour does not make contact with the second component part in the region of the connection radius. That is to say that the inner contour and the second component part are free of contact or do not touch at the connection radius.

Furthermore, a lithography apparatus is proposed. The lithography apparatus concomitantly comprises a sealing device as explained above and/or a component as explained above.

The lithography apparatus can be an EUV lithography apparatus or a DUV lithography apparatus. EUV stands for "extreme ultraviolet" and denotes a wavelength of the working light of between <NUM> and <NUM>. DUV stands for "deep ultraviolet" and denotes a wavelength of the working light of between <NUM> and <NUM>.

"A(n); one" in the present case should not necessarily be understood as restrictive to exactly one element. Rather, a plurality of elements, such as, for example, two, three or more, can also be provided. Any other numeral used here, too, should not be understood to the effect that there is a restriction to exactly the stated number of elements. Rather, numerical deviations upwards and downwards are possible, unless indicated to the contrary.

The embodiments and features described for the sealing device are correspondingly applicable to the proposed component and respectively to the proposed lithography apparatus, and vice versa.

Further advantageous configurations and aspects of the invention are the subject matter of the dependent claims and also of the exemplary embodiments of the invention described below. In the text that follows, the invention is explained in more detail on the basis of preferred embodiments and with reference to the accompanying figures.

Identical elements or elements having an identical function have been provided with the same reference signs in the figures, unless indicated to the contrary. It should also be noted that the illustrations in the figures are not necessarily true to scale.

<FIG> shows a schematic view of an EUV lithography apparatus 100A, which comprises a beam shaping and illumination system <NUM> and a projection system <NUM>. In this case, EUV stands for "extreme ultraviolet" and denotes a wavelength of the working light of between <NUM> and <NUM>. The beam shaping and illumination system <NUM> and the projection system <NUM> are respectively provided in a vacuum housing (not shown), each vacuum housing being evacuated with the aid of an evacuation device (not shown). The vacuum housings are surrounded by a machine room (not shown), in which drive devices for mechanically moving or setting optical elements are provided. Moreover, electrical controllers and the like can also be provided in this machine room.

The EUV lithography apparatus 100A comprises an EUV light source 106A. A plasma source (or a synchrotron), which emits radiation 108A in the EUV range (extreme ultraviolet range), that is to say for example in the wavelength range of <NUM> to <NUM>, can for example be provided as the EUV light source 106A. In the beam shaping and illumination system <NUM>, the EUV radiation 108A is focused and the desired operating wavelength is filtered out from the EUV radiation 108A. The EUV radiation 108A generated by the EUV light source 106A has a relatively low transmissivity through air, for which reason the beam guiding spaces in the beam shaping and illumination system <NUM> and in the projection system <NUM> are evacuated.

The beam shaping and illumination system <NUM> illustrated in <FIG> has five mirrors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. After passing through the beam shaping and illumination system <NUM>, the EUV radiation 108A is guided onto a photomask (called a reticle) <NUM>. The photomask <NUM> is likewise embodied as a reflective optical element and can be arranged outside the systems <NUM>, <NUM>. Furthermore, the EUV radiation 108A can be directed onto the photomask <NUM> by means of a mirror <NUM>. The photomask <NUM> has a structure which is imaged onto a wafer <NUM> or the like in a reduced fashion by means of the projection system <NUM>.

The projection system <NUM> (also referred to as projection lens) has six mirrors M1 to M6 for imaging the photomask <NUM> onto the wafer <NUM>. In this case, individual mirrors M1 to M6 of the projection system <NUM> can be arranged symmetrically in relation to an optical axis <NUM> of the projection system <NUM>. It should be noted that the number of mirrors M1 to M6 of the EUV lithography apparatus 100A is not restricted to the number represented. A greater or lesser number of mirrors M1 to M6 can also be provided. Furthermore, the mirrors M1 to M6 are generally curved on their front face for beam shaping.

<FIG> shows a schematic view of a DUV lithography apparatus 100B, which comprises a beam shaping and illumination system <NUM> and a projection system <NUM>. In this case, DUV stands for "deep ultraviolet" and denotes a wavelength of the working light of between <NUM> and <NUM>. As has already been described with reference to <FIG>, the beam shaping and illumination system <NUM> and the projection system <NUM> can be arranged in a vacuum housing and/or surrounded by a machine room with corresponding drive devices.

The DUV lithography apparatus 100B has a DUV light source 106B. By way of example, an ArF excimer laser that emits radiation 108B in the DUV range at <NUM>, for example, can be provided as the DUV light source 106B.

The beam shaping and illumination system <NUM> illustrated in <FIG> guides the DUV radiation 108B onto a photomask <NUM>. The photomask <NUM> is embodied as a transmissive optical element and can be arranged outside the systems <NUM>, <NUM>. The photomask <NUM> has a structure which is imaged onto a wafer <NUM> or the like in a reduced fashion by means of the projection system <NUM>.

The projection system <NUM> has a plurality of lens elements <NUM> and/or mirrors <NUM> for imaging the photomask <NUM> onto the wafer <NUM>. In this case, individual lens elements <NUM> and/or mirrors <NUM> of the projection system <NUM> can be arranged symmetrically in relation to an optical axis <NUM> of the projection system <NUM>. It should be noted that the number of lens elements <NUM> and mirrors <NUM> of the DUV lithography apparatus 100B is not restricted to the number represented. A greater or lesser number of lens elements <NUM> and/or mirrors <NUM> can also be provided. Furthermore, the mirrors <NUM> are generally curved on their front face for beam shaping.

An air gap between the last lens element <NUM> and the wafer <NUM> can be replaced by a liquid medium <NUM> which has a refractive index of > <NUM>. The liquid medium <NUM> can be high-purity water, for example. Such a construction is also referred to as immersion lithography and has an increased photolithographic resolution. The medium <NUM> can also be referred to as an immersion liquid.

<FIG> shows a plan view of a component <NUM> for an EUV lithography apparatus 100A as explained above. By way of example, the component <NUM> can be part of the beam shaping and illumination system <NUM> or of the projection system <NUM> of the EUV lithography apparatus 100A. However, the component <NUM> can also be part of a DUV lithography apparatus 100B as explained above.

The component <NUM> can be a so-called Actuation Sensor Unit (ASU), for example, with the aid of which facets of a facet mirror, for example of a field facet mirror or of a pupil facet mirror, can be deflected. Such a facet mirror having deflectable facets can be part of the beam shaping and illumination system <NUM>, for example.

The component <NUM> comprises a first component part <NUM>. The first component part <NUM> can be for example a main body or frame of the component <NUM>. The first component part <NUM> can be produced from metal, preferably from copper, high-grade steel or aluminium. Preferably, the first component part <NUM> is actively cooled. "Actively cooled" should be understood in the present case to mean that a fluid, for example water, is guided through the first component part <NUM> in order to absorb heat there and transport it away. For this purpose, the first component part <NUM> can comprise a cooling system <NUM>, in particular a cooling circuit, which is illustrated highly schematically in <FIG>. The cooling system <NUM> can be formed with the aid of cooling channels provided in the first component part <NUM>.

The component <NUM> comprises a multiplicity of second component parts <NUM>, only one of which, however, is provided with a reference sign in <FIG>. The second component part <NUM> can be an Actuation Sensor Package (ASP), for example, which is suitable for deflecting a facet of a facet mirror as mentioned above. In this case, a second component part <NUM> of this type is assigned to each facet. Preferably, a multiplicity of second component parts <NUM> are provided. By way of example, hundreds of second component parts <NUM> can be provided. As shown in <FIG>, the second component parts <NUM> are arranged in the shape of a grid or in the shape of a pattern. The second component parts <NUM> can have a circular-cylindrical geometry.

The second component parts <NUM> are received in the first component part <NUM> at least in sections and are sealed vis-à-vis said first component part. The second component parts <NUM> can be cooled with the aid of the cooling system <NUM>. The first component part <NUM> has receiving sections, for example holes or recesses, in which the second component parts <NUM> are received in sections.

<FIG> shows a schematic section view through two second component parts <NUM> in accordance with the sectional line III-III in <FIG>. <FIG> shows the detail view IV in accordance with <FIG>. Reference is made below to <FIG> and <FIG> simultaneously.

As already mentioned, the first component part <NUM> comprises receiving sections <NUM>, in which the second component parts <NUM> are received. The receiving sections <NUM> can be embodied as holes in the first component part <NUM>. The first component part <NUM> furthermore comprises one sealing surface <NUM> or a plurality of sealing surfaces <NUM>. In particular, a sealing surface <NUM> of this type is assigned to each second component part <NUM>. The sealing surfaces <NUM> each extend circularly around the corresponding second component part <NUM>. As shown in <FIG>, the second component parts <NUM> each project above the sealing surface <NUM> assigned thereto.

Each second component part <NUM> comprises a main body <NUM> having a cylindrical base section <NUM> and a flange section <NUM> extending around the base section <NUM>. The base section <NUM> can be constructed rotationally symmetrically with respect to a centre axis or axis of symmetry <NUM>. The flange section <NUM> is not constructed rotationally symmetrically with respect to the axis of symmetry <NUM>.

The flange section <NUM> can be polygonal. As viewed along the sectional line III-III, a distance A1 between flange sections <NUM> of two adjacent second component parts <NUM> is only a few hundred µm. By way of example, the distance A1 can be <NUM>. The base section <NUM> is received in the receiving section <NUM> and projects beyond the corresponding sealing surface <NUM>. The flange section <NUM> comprises in each case a sealing surface <NUM> respectively facing a corresponding sealing surface <NUM> of the first component part <NUM>.

A ring body <NUM> is placed onto the main body <NUM>. The ring body <NUM> is closed off with a ceramic plate towards the top in the orientation in <FIG>. The ceramic plate can be soldered into the ring body <NUM>. The ring body <NUM> can be welded to the main body <NUM>. Each second component part <NUM> comprises a sensor system and an actuator. The actuator can comprise a plurality of coils.

The second component parts <NUM>, in particular the sealing surfaces <NUM>, are sealed vis-à-vis the first component part <NUM>, in particular the sealing surfaces <NUM>, with the aid of a sealing device <NUM>. For this purpose, the sealing device <NUM> is positioned and pressed between the sealing surfaces <NUM>, <NUM>. A yielding volume <NUM> for the pressing of the sealing device <NUM> is provided in each case between the sealing device <NUM> and the base sections <NUM>. The yielding volume <NUM> can be referred to as a compensation volume.

<FIG> shows a schematic sectional view through two second component parts <NUM> in accordance with the sectional line V-V in <FIG>. <FIG> shows the detail view VI in accordance with <FIG>. Reference is made below to <FIG> and <FIG> simultaneously.

As viewed along the sectional line V-V, the first component part <NUM> extends out over the sealing surfaces <NUM> with a bearing section <NUM>. The second component parts <NUM> bear on the bearing sections <NUM> in such a way that the sealing surfaces <NUM>, <NUM> are positioned at a defined distance away from one another. The distance A1 is significantly larger when viewed along the sectional line V-V than when viewed along the sectional line III-III.

The comparison of <FIG> and <FIG> with <FIG> and <FIG> shows that very little structural space is present along the sectional line III-III. There is a very small overlap between the sealing surfaces <NUM> of the second component parts <NUM> and the sealing device <NUM>. A decentration of the sealing device <NUM> in relation to the respective axis of symmetry <NUM> can easily lead to leakage for this reason. Furthermore, between adjacent second component parts <NUM>, there is also only a very small or almost no yielding volume <NUM> for the pressing of the sealing device <NUM>. Therefore, leaks can occur between two adjacent second component parts <NUM>.

Along the sectional line V-V, by contrast, the ridge-shaped bearing section <NUM> is provided between two adjacent second component parts <NUM>, the flange sections <NUM> of the second component parts <NUM> being supported on said bearing section. The sealing device <NUM> extends between the bearing section <NUM> and the base sections <NUM> of the main body <NUM> of the respective second component part <NUM>. Significantly more structural space is present between adjacent second component parts <NUM> in comparison with a view along the sectional line III-III. There is a significantly larger overlap between the sealing surfaces <NUM> of the second component parts <NUM> and the sealing device <NUM>. Therefore, a decentration of the sealing device <NUM> is rather noncritical here with regard to leaks. The yielding volume <NUM> for the pressing of the sealing device <NUM> is also significantly larger as viewed along the sectional line V-V.

If an internal diameter of the sealing device <NUM> is then increased in order to enlarge the yielding volume <NUM>, the centring of the sealing device <NUM> is no longer ensured, however. The lack of centring of the sealing device <NUM> can have the effect that in the view along the sectional line III-III the sealing device <NUM> bears against one of two adjacent second component parts <NUM> and is spaced apart by double the distance from the other of the two second component parts <NUM>. Leaks can occur on account of the small overlap between the sealing surface <NUM> and the sealing device <NUM>. No overlap at all between the sealing surface <NUM> and the sealing device <NUM> occurs in the worst case. This must be avoided.

The small structural space between the second component parts <NUM> does not permit the sealing device <NUM> to be separated into individual sealing rings, for example into O-rings. Furthermore, individual sealing rings cannot be prevented from tilting away on account of the small structural space. Therefore, the sealing device <NUM>, as shown in <FIG>, is produced as a sealing mat, which is cut out from a suitable plastics material with the aid of a laser, for example. By way of example, a perfluoro rubber (FFKM) can be used as suitable material.

As shown in <FIG>, the sealing device <NUM> comprises a multiplicity of sealing rings <NUM> connected to one another, only one of which, however, is provided with a reference sign in <FIG>. By virtue of the fact that the sealing rings <NUM> are connected to one another, the sealing rings <NUM> are prevented from tilting away.

<FIG> shows the detail view IIX in accordance with <FIG>. The sealing rings <NUM> are connected to one another at connection locations <NUM>, only two of which are provided with a reference sign in <FIG>. The sealing device <NUM> is thus an integral component part, in particular one which is materially in one piece. "Integral" should be understood to mean in the present case that the sealing device <NUM> forms a single component part, which is not constructed from mutually separate component parts. That is to say that the sealing rings <NUM> are fixedly connected to one another, wherein the totality of all the sealing rings <NUM> forms the sealing device <NUM>. "Materially in one piece" should be understood in the present case to mean that the sealing device <NUM> is an integral component part produced from the same material throughout.

The sealing rings <NUM> each have an external diameter DA, which is constant and which is flattened only in the region of the connection locations <NUM>. For the case where the sealing rings <NUM> are embodied such that they each also have a constant internal diameter chosen in such a way that a centring on the respective base section <NUM> of the second component parts <NUM> is effected, the problem arises that, as viewed along the sectional line III-III in <FIG>, almost no yielding volume <NUM> for the pressing of the sealing device <NUM> is present. Consequently, the sealing device <NUM> cannot be pressed sufficiently between adjacent second component parts <NUM>.

This can have the consequence that either the sealing device <NUM> is damaged, which can lead to leaks, or a required installation position of the respective second component part <NUM> cannot be attained. This last can lead to position errors in a height direction (z-error) of the component <NUM>. In order to obtain a sufficient yielding volume <NUM>, the internal diameter of the sealing rings <NUM> can be increased, such that a sufficiently large yielding volume <NUM> is kept available between the second component parts <NUM> and the sealing device <NUM>. However, this has the disadvantage that a sufficient centring at the base sections <NUM> of the second component parts <NUM> is not ensured. The sealing rings <NUM> then do not bear circumferentially against the base sections <NUM>, which can lead to leaks over time or directly in the course of mounting.

In order then to obtain a sufficiently large yielding volume <NUM> and a good centring at the same time, the sealing rings <NUM> each comprise an inner contour <NUM> which is not circular, but rather, as will be explained below, is trefoiled. That is to say that the sealing rings <NUM> have a varying internal diameter rather than a constant internal diameter. Reference is made below to just one sealing ring <NUM>. A theoretical internal diameter DI of the sealing ring <NUM> is illustrated by a dashed line in <FIG>. The internal diameter DI corresponds to an external diameter of the base section <NUM> of the second component parts <NUM>.

Each sealing ring <NUM> comprises a first plane of symmetry E1 and a second plane of symmetry E2. The planes of symmetry E1, E2 are positioned perpendicularly to one another and intersect one another. The sealing ring <NUM> is constructed symmetrically, in particular mirror-symmetrically, both with respect to the first plane of symmetry E1 and with respect to the second plane of symmetry E2. The diameters DA, DI have their centre point on a line of intersection of the two planes of symmetry E1, E2. A coordinate system having a first spatial direction or x-direction x, a second spatial direction or y-direction y and a third spatial direction or z-direction z is assigned to the sealing ring <NUM>. The directions x, y, z are positioned perpendicularly to one another.

Furthermore, an azimuth direction or circumferential direction U is also assigned to the sealing ring <NUM>. The circumferential direction U can be oriented in the clockwise or anticlockwise direction. The circumferential direction U is oriented in the anticlockwise direction in <FIG>. The circumferential direction U runs along the inner contour <NUM>.

The connection locations <NUM> are arranged mirror-symmetrically both with respect to the first plane of symmetry E1 and with respect to the second plane of symmetry E2. A respective azimuth angle α, β is provided between two adjacent connection locations <NUM>. The azimuth angle α can be referred to as first azimuth angle. The azimuth angle β can be referred to as second azimuth angle. The azimuth angle β is greater than the azimuth angle α. By way of example, the azimuth angle α is approximately <NUM>° and the azimuth angle β is approximately <NUM>°. The azimuth angle α is provided in each case between two connection locations <NUM> arranged mirror-symmetrically with respect to the first plane of symmetry E1. The azimuth angle β is provided in each case between two connection locations <NUM> arranged mirror-symmetrically with respect to the second plane of symmetry E2.

The sealing ring <NUM> comprises a connection radius R304 at the connection locations <NUM>. The inner contour <NUM> thus has the connection radius R304 in the region of the connection locations <NUM>. That is to say that four connection radii R304 are provided, only one of which, however, is shown in <FIG>. A respective centre point MR304-<NUM> to MR304-<NUM> of the connection radius R304 lies outside the planes of symmetry E1, E2. Four centre points MR304-<NUM> to MR304-<NUM> are provided, which lie on lines of symmetry L1 to L3 of the connection locations <NUM>. Each connection location <NUM> is assigned a line of symmetry L1 to L3, wherein only three lines of symmetry L1 to L3 are shown in <FIG>. The connection locations <NUM> are constructed in each case symmetrically with respect to the lines of symmetry L1 to L3. In other words, the lines of symmetry L1 to L3 run centrally through the connection locations <NUM>. The azimuth angles α, β are plotted between the lines of symmetry L1 to L3.

The centre points MR304-<NUM> to MR304-<NUM> are positioned mirror-symmetrically with respect to the planes of symmetry E1, E2. The centre points MR304-<NUM>, MR304-<NUM> and the centre points MR304-<NUM>, MR304-<NUM> are positioned in a manner spaced apart by a distance A2 from one another in the y-direction y. The centre points MR304-<NUM>, MR304-<NUM> and the centre points MR304-<NUM>, MR304-<NUM> are positioned in a manner spaced apart by a distance A3 from one another in the x-direction x. The distance A2 is greater than the distance A3. The respective connection radius R304 extends over an azimuth angle γ in the circumferential direction U. The azimuth angle γ is <NUM>°, for example. For the case where the azimuth angles α, β are each <NUM>°, the distances A2, A3 are equal in magnitude. The connection radius R304 is less than half the internal diameter DI.

The inner contour <NUM> has a respective first intermediate radius R11, R12 between two connection locations <NUM> which are adjacent in the x-direction x. The inner contour <NUM> comprises two first intermediate radii R11, R12. The first intermediate radii R11, R12 are situated respectively at the top and bottom in the orientation in <FIG>. The first intermediate radii R11, R12 are each greater than the connection radius R304. It thus holds true that: R11, R12 > R304.

A respective centre point MR11, MR12 of the first intermediate radii R11, R12 is situated on the first plane of symmetry E1 and is offset respectively upwards and downwards in relation to the second plane of symmetry E2 in the orientation in <FIG>. As viewed in the y-direction y, the centre points MR11, MR12 of the first intermediate radii R11, R12 are positioned in a manner spaced apart by a distance A4 from one another. In this case, the centre point MR11 is assigned to the first intermediate radius R11. The centre point MR12 is assigned to the first intermediate radius R12.

The inner contour <NUM> comprises a respective second intermediate radius R21, R22 between two connection locations <NUM> which are adjacent in the y-direction y. The inner contour <NUM> comprises two second intermediate radii R21, R22. The second intermediate radii R21, R22 are situated respectively on the left and right in the orientation in <FIG>. The second intermediate radii R21, R22 are in each case greater than the connection radius R304 and less than the first intermediate radii R11, R12. It thus holds true that: R <NUM>, R12 > R21, R22 > R304. However, other suitable size relationships can also be chosen. The intermediate radii R11, R12, R21, R22 are greater than half the internal diameter DI.

A respective centre point MR21, MR22 of the second intermediate radii R21, R22 is situated on the second plane of symmetry E2 and is offset respectively towards the left and right in relation to the first plane of symmetry E1 in the orientation in <FIG>. As viewed in the x-direction x, the centre points MR21, MR22 of the second intermediate radii R21, R22 are positioned in a manner spaced apart by a distance A5 from one another. In this case, the centre point MR21 is assigned to the second intermediate radius R21. The centre point MR22 is assigned to the second intermediate radius R22. The distance A4 is greater than the distance A5. For the case where the azimuth angles α, β are each <NUM>° and thus equal in magnitude, the distances A4, A5 are equal in magnitude. Accordingly, the intermediate radii R11, R12, R21, R22 can also be equal in magnitude.

The inner contour <NUM> furthermore comprises optional transition radii RU, with the aid of which the intermediate radii R11, R12, R21, R22 transition into the respective connection radius R304. In each case two transition radii RU are provided per connection location <NUM>. The transition radii RU are preferably identical, but can also be embodied individually. The transition radii RU provide for a continuously variable transition from the respective connection radius R304 into the intermediate radii R11, R12, R21, R22.

The prestress of the sealing ring <NUM> on the base section <NUM> of the respective second component part <NUM> is proportional to the azimuth angle α, β. Given an azimuth angle α of <NUM>°, by way of example, a shortening of the sealing ring <NUM> between the corresponding connection locations <NUM> by α/<NUM>° or <NUM>°/<NUM>° is necessary. Given different distances or different azimuth angles α, β, mutually different first intermediate radii R11, R12 and second intermediate radii R21, R22 are chosen, as mentioned above. It is thereby possible to prevent the connection locations <NUM> from moving azimuthally during mounting and the sealing device <NUM> from warping as a result.

By virtue of the fact that the inner contour <NUM> has the connection radius R304 in the region of the connection locations <NUM>, said connection radius being chosen such that it is less than the external diameter of the base section <NUM> of the second component parts <NUM> and thus the internal diameter DI, a sufficiently large yielding volume <NUM> for the pressing of the sealing ring <NUM> can be provided at the connection locations <NUM>.

In the region between the connection locations <NUM> at which the intermediate radii R11, R12, R21, R22 are provided, by contrast, the inner contour <NUM> experiences a constriction or narrowing, such that the inner contour <NUM> bears against the base section <NUM> and can be centred there. Consequently, between the connection locations <NUM>, the inner contour <NUM> bears against the base section <NUM> with a prestress. The narrowing of the inner contour <NUM> between the connection locations <NUM> and the widening of said inner contour at the connection locations <NUM> result in the inner contour <NUM> having the trefoiled or trefoil-like design mentioned above.

<FIG> shows the detail view IV in accordance with <FIG> shows a connection location <NUM> between two sealing rings <NUM> in detail. A respective yielding volume <NUM> is provided at the connection location <NUM> on both sides, said yielding volume, like the yielding volume <NUM>, enabling the sealing rings <NUM> to be pressed. The yielding volume <NUM> can be referred to as a compensating volume. Unlike the yielding volume <NUM>, however, the yielding volumes <NUM> are provided directly at the sealing device <NUM>. A connection web <NUM> is provided between the yielding volumes <NUM>, said connection web connecting adjacent sealing rings <NUM> to one another integrally. The connection location <NUM> itself has a width B304 at the connection web <NUM>. The width B304 can be two millimetres, for example.

The yielding volumes <NUM> can be embodied as flattened portions of the respective external diameter DA of the sealing rings <NUM>. That is to say that the external diameters DA of adjacent sealing rings <NUM> do not transition into one another. By way of example, the yielding volumes <NUM> are embodied in each case as a cutout or groove extending completely through a wall thickness W300 (<FIG>) of the sealing device <NUM>. In this case, the groove-type yielding volumes <NUM> can have a width B308. The width B308 can be for example <NUM> to <NUM>, in particular <NUM>, millimetre. The wall thickness W300 can be <NUM> to <NUM>, in particular <NUM>, millimetres.

<FIG> shows a development of the connection location <NUM> explained with reference to <FIG> and <FIG>. In contrast to <FIG> and <FIG>, the yielding volumes <NUM> do not extend completely through the wall thickness W300, but rather only to a depth T308. The depth T308 can be <NUM> millimetre, for example.

<FIG> shows once again the detail view IV in accordance with <FIG>, but a development of the connection location <NUM> shown in <FIG> and <FIG> is illustrated in <FIG>. In this case, the yielding volumes <NUM> are not embodied as cutouts or grooves. Rather, the yielding volumes <NUM> comprise a multiplicity of holes <NUM>, <NUM>, <NUM> positioned next to one another, only three of which, however, are provided with a reference sign in <FIG>. The number of holes <NUM>, <NUM>, <NUM> is arbitrary. By way of example, it is possible to provide six holes <NUM>, <NUM>, <NUM> of this type per yielding volume <NUM>.

The holes <NUM>, <NUM>, <NUM> can be circular and have a diameter D308 in each case. However, the holes <NUM>, <NUM>, <NUM> can also have any other geometry. By way of example, the holes <NUM>, <NUM>, <NUM> can also be oval or polygonal. The diameter D308 can be <NUM> millimetre, for example. The holes <NUM>, <NUM>, <NUM> can all have the same diameter D308 or mutually different diameters D308. The holes <NUM>, <NUM>, <NUM> can be arranged in one row, as shown in <FIG>. Alternatively, the holes <NUM>, <NUM>, <NUM> can also be arranged in a plurality of rows. The holes <NUM>, <NUM>, <NUM> can be positioned in a manner spaced apart from one another uniformly or non-uniformly.

The connection location <NUM> itself, as shown in <FIG>, along the width B304, that is to say at the connection web <NUM>, can be free of holes <NUM>, <NUM>, <NUM> or hole-free or holeless. The holes <NUM>, <NUM>, <NUM> can extend through the entire wall thickness W300 or only to the depth T308 explained above.

<FIG> shows once again the detail view IV in accordance with <FIG>, but a development of the connection location <NUM> shown in <FIG> is illustrated in <FIG>. In this case the yielding volumes <NUM> each comprise a plurality of rows <NUM>, <NUM> of holes, which in turn have a multiplicity of holes <NUM>, <NUM>, <NUM> as explained above. The number of rows <NUM>, <NUM> of holes is arbitrary. The holes <NUM>, <NUM>, <NUM> can be arranged in two rows, as shown in <FIG>. However, the holes <NUM>, <NUM>, <NUM> can also be arranged in three rows or in four rows. The individual holes <NUM>, <NUM>, <NUM> of the rows <NUM>, <NUM> of holes can be positioned next to one another, as shown in <FIG>. However, the holes <NUM>, <NUM>, <NUM> can also be arranged offset with respect to one another.

<FIG> shows once again the detail view IV in accordance with <FIG>, but a development of the connection location <NUM> shown in <FIG> is illustrated in <FIG>. In this embodiment of the connection location <NUM>, the entire connection web <NUM> is provided with holes <NUM>, <NUM>, <NUM>, such that only a single continuous yielding volume <NUM> formed from holes <NUM>, <NUM>, <NUM> is provided.

Claim 1:
Sealing device (<NUM>) for sealing a first component part (<NUM>) of a lithography apparatus (100A, 100B) vis-à-vis a multiplicity of second component parts (<NUM>) of the lithography apparatus (100A, 100B), comprising
a multiplicity of sealing rings (<NUM>), and
a multiplicity of connection locations (<NUM>),
characterised in that
the sealing rings (<NUM>) are integrally connected to one another with the aid of the connection locations (<NUM>).