Patent Publication Number: US-2023156898-A1

Title: Contamination shield for mechanically insulating device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Application No. 63/020,760, filed May 06, 2020 and titled CONTAMINATION SHIELD FOR MECHANICAL INSULATING DEVICE and which is incorporated herein in its entirety by reference. 
    
    
     TECHNICAL FIELD 
     The disclosed subject matter relates to an apparatus for shielding a mechanically insulating device such as a flexible bellows from unwanted materials. 
     BACKGROUND 
     A fluid material (such as a liquid, a gas, or a partial liquid) that moves in a system can collide with a surface (an impact surface) in the system. The collision with the impact surface can result in splashing, deposition, and/or scattering of the material, and the splashing, deposition, and/or scattering can result in contamination of the impact surface and objects near the impact surface. The contamination can be, for example, bits of material that are flung from the material as a result of the collision. The contamination of the object can result in the performance of the object and/or the entire system being degraded. 
     For example, the system can include an optical element such as a mirror, and contamination of the mirror can change the reflective properties of the mirror. The mirror can be a mirror in an extreme ultraviolet (EUV) light source, and the contamination can result in reduced amounts of EUV light being output by the EUV light source. 
     EUV light, for example, electromagnetic radiation having wavelengths of 100 nanometers (nm) or less (also sometimes referred to as soft x-rays), and including light at a wavelength of, for example, 20 nm or less, between 5 and 20 nm, or between 13 and 14 nm, can be used in photolithography processes to produce extremely small features in substrates, for example, silicon wafers, by initiating polymerization in a resist layer. Methods to produce EUV light include, but are not necessarily limited to, converting a material that includes an element, for example, xenon, lithium, or tin, with an emission line in the EUV range in a plasma state. In one such method, often termed laser produced plasma (“LPP”), the required plasma is produced by irradiating a target material, for example, in the form of a droplet, plate, tape, stream, or cluster of material, with an amplified light beam. For this process, the plasma is typically produced in a sealed vessel, for example, a vacuum chamber, and monitored using various types of metrology equipment. 
     During operation, an EUV light source utilizes and produces gasses, liquids, and partial liquids (such as the plasma effluent) that are delivered between components and pass through various mechanical connective devices that provide conduits for the fluid flow between the components. 
     SUMMARY 
     In some general aspects, an apparatus includes: a mechanically insulating device having a flexible bellows extending between first and second flanges; a rigid inner sleeve; and a shield device. The flexible bellows defines a bellows passageway that extends along an axial direction between openings of the first and second flanges. The rigid inner sleeve is affixed to or supported by the first flange and extends along the bellows passageway in the axial direction. The rigid inner sleeve has an outer diameter that is less than an inner diameter of the flexible bellows. The shield device is at least partly fixed to or supported by the second flange and defines an axial device opening having a diameter that is less than the inner diameter of the flexible bellows and is greater than the outer diameter of the rigid inner sleeve. The shield device is configured to enable relative motion between the first and second flanges, the relative motion including translational motion along one or more directions that are perpendicular to the axial direction and rotational motion about one or more directions that are perpendicular to the axial direction. 
     Implementations can include one or more of the following features. For example, the shield device can extend into the bellows passageway. 
     A distance between an inner diameter of the flexible bellows and the outer diameter of the rigid inner sleeve can be greater than about 10%, greater than about 20%, or greater than about 30% of the inner diameter of the flexible bellows. 
     The shield device can include one or more disks that extend along a direction that is not parallel to the axial direction. The direction in which the one or more disks extend can be perpendicular to the axial direction. The one or more disks can include a plurality of disks. An outer diameter of at least one disk can be different from the outer diameter of each other disk, and an inner diameter of at least one disk can be different from the inner diameter of each other disk. An outer diameter of at least one disk can be equal to the outer diameter of another disk, and an inner diameter of at least one disk can be equal to the inner diameter of another disk. Each disk can be constrained from moving along the axial direction and can be free to move along a direction not parallel to the axial direction. Each disk can be defined by a thickness along the axial direction that allows each disk to be installed adjacent to the second flange. Each of the one or more disks can include a slit that extends from an outer diameter of the disk to an inner diameter of the disk, the slit allowing each disk to be installed adjacent to the second flange. The shield device can also include a disk housing configured to retain the one or more disks. The disk housing can be defined by an inner diameter that is equal to the inner diameter of the flexible bellows. At least one disk of the one or more disks can have an outer diameter that is greater than an inner diameter of the disk housing. The one or more disks can include a plurality of disks. If any one of the disks is a small disk that has an outer diameter that is less than a sum of an inner diameter of the disk housing plus an annular radius of the disk housing, then the small disk can be sandwiched between two disks each having outer diameters that are greater than the sum of the inner diameter of the disk housing plus the annular radius of the disk housing. 
     Each disk can be defined by a thickness along the axial direction such that the one or more disks are receivable within the disk housing. 
     The shield device can be configured to at least partially cover or mostly cover a region between the flexible bellows and the rigid inner sleeve so that the shield device block particulates from entering this region. The particulates can include one or more of solid particles, fluid particles, and splashes. 
     The flexible bellows can include pleats configured to fold and unfold to enable the relative motion between the first and second flanges. 
     The shield device can be made of a metal that includes a coating configured to prevent particulates from contaminating the shield device. The particulates can include one or more of solid particles, fluid particles, and splashes. And, the shield device coating can be configured to: repel fluid particles to thereby prevent the fluid particles from accumulating on the shield device; and prevent solid particles solidified on the shield device from sticking to the shield device. The shield device coating can be further configured to prevent corrosion of an exterior surface of the shield device, such corrosion being caused by contamination by the particulates. The metal can be stainless steel and the shield device coating can be a metal nitride or a metal oxide. 
     The rigid inner sleeve can be made of a metal. The metal can have a high thermal conductivity. The rigid inner sleeve can be made of molybdenum, aluminum, copper, aluminum oxide, diamond, or graphite. The rigid inner sleeve can include a coating configured to prevent particulates from contaminating one or more of the shield device and the rigid inner sleeve. The particulates can include one or more of: solid particles, fluid particles, and splashes. The rigid inner sleeve coating can be configured to: repel the fluid particles to thereby prevent the fluid particles from accumulating on the shield device; and prevent solid particles solidified on the shield device from sticking to the shield device. The rigid inner sleeve coating can be configured to repel fluid particles along a direction that is parallel with the axial direction or away from the shield device such that when a fluid propagates through the rigid inner sleeve such fluid detaches from the rigid inner sleeve having a propagation direction that is parallel with the axial direction or away from the shield device. The rigid inner sleeve coating can be further configured to prevent corrosion of an exterior surface of the shield device, such corrosion caused by contamination of the particulates. The rigid inner sleeve coating can be a metal nitride, a metal oxide, or a silicon nitride. 
     The apparatus can also include a heating apparatus configured to adjust a temperature of the rigid inner sleeve. The heating apparatus can be in direct thermal communication with an outer surface of the rigid inner sleeve to adjust the temperature of the rigid inner sleeve by thermal conduction. The heating apparatus can be arranged to not be in direct thermal communication with the flexible bellows. 
     The first and second flanges can be vacuum flanges. 
     The apparatus can also include an inner guard extending over an opening of one or more of: the first flange and the second flange. The inner guard can be made of a metal that includes a guard coating configured to prevent particulates from contaminating the inner guard. The distance between the inner guard and the respective flange can be small enough to reduce an amount of particulates from contaminating the respective flange. The distance between the inner guard and the respective flange can be configured to reduce the amount of particulates from contaminating the respective flange at least in part because particles are repelled from the surfaces of the inner guard and the respective flange. The particulates can include one or more of solid particles, fluid particles, and splashes. The coating can be configured to: repel the fluid particles to prevent the fluid particles from accumulating on the inner guard; and prevent the solid particles from sticking to the inner guard. The guard coating can be a metal nitride. 
     The rigid inner sleeve and the shield device can be arranged so that the rigid inner sleeve is configured to penetrate the opening of the shield device. 
     The flexible bellows can be coupled or fixed at a first end to the first flange and at a second end to the second flange. The rigid inner sleeve can be either affixed directly to the first flange or affixed to a first end of the flexible bellows that is fixed to the first flange. 
     In other general aspects, an extreme ultraviolet (EUV) light source includes: a chamber comprising a chamber wall defining a fluid portal; and an apparatus retained at the chamber wall. The apparatus includes: a mechanically insulating device including a flexible bellows extending between first and second flanges; a rigid inner sleeve; and a shield device. The flexible bellows defines a bellows passageway that extends along an axial direction between openings of the first and second flanges, such openings being in fluid communication with the fluid portal. The rigid inner sleeve is affixed to or supported by the first flange and extends along the bellows passageway in the axial direction. The inner sleeve has an outer diameter that is less than an inner diameter of the flexible bellows. The shield device is at least partly fixed to or supported by the second flange and defines an axial device opening having a diameter that is less than the inner diameter of the flexible bellows and is greater than the outer diameter of the rigid inner sleeve. The shield device is configured to enable relative motion between the first and second flanges caused by movement of the chamber wall, the relative motion including translational motion along one or more directions that are perpendicular to the axial direction and rotational motion about one or more directions that are perpendicular to the axial direction. 
     Implementations can include one or more of the following features. For example, the first flange can be fixed to the chamber wall and the second flange can be fixed to a second wall of a second chamber. The EUV light source can further include a target material supply system including a droplet generator configured to produce a stream of targets. The targets include a target material that emits EUV light when in a plasma state. The EUV light source can also include a structure defining a structure passageway configured to receive target material that travels along a target material path. The first flange can be fixed to a wall of the structure. The second flange can be fixed to a wall of a receptacle configured to receive target material from the structure passageway. The first and second flanges can be vacuum flanges, the first flange can be fixed to the wall of the structure with a vacuum seal, and the second flange can be fixed to the wall of the receptacle with another vacuum seal. The EUV light source can further include a first inner guard extending over the opening of the first flange, and a second inner guard extending over the opening of the second flange. Each of the first and second inner guards can be configured to: block the target material from contacting the respective vacuum seal; and prevent the target material from solidifying between the respective flange and the structure wall at the location of the vacuum seal to thereby form an unwanted joint between the respective flange and the structure wall. The structure can be arranged at a location of the chamber opposite to the droplet generator. The structure passageway can coincide with a direction of gravity and a flow direction of the target material at least partly coincides with the direction of gravity. 
     The apparatus can be implemented as a gravity-driven drain configured to pass or trap target material traveling within the chamber. 
     In other general aspects, an apparatus includes: a mechanically insulating device including a flexible bellows extending between first and second flanges; a rigid inner sleeve; and a shield device. The flexible bellows defines a bellows passageway that extends along an axial direction between openings of the first and second flanges. The rigid inner sleeve is affixed to or supported by the first flange and extends along the bellows passageway in the axial direction. The inner sleeve has an outer diameter that is less than an inner diameter of the flexible bellows. The shield device is at least partly fixed to or supported by the second flange and defines an axial device opening having a diameter that is less than the inner diameter of the flexible bellows and is greater than the outer diameter of the rigid inner sleeve. The shield device is configured to at least partially cover or mostly cover a region between the flexible bellows and the rigid inner sleeve so that the shield device block particulates from entering this region. 
     Implementations can include one or more of the following features. For example, the shield device can include one or more movable disks supported by a disk housing fixed to the second flange, each disk defining an opening large enough to accommodate the rigid inner sleeve. Each disk can have an inner diameter that is less than the inner diameter of the flexible bellows. The one or more movable disks can be configured to enable relative motion between the first and second flanges, the relative motion including translational motion along one or more directions that are perpendicular to the axial direction and rotational motion about one or more directions that are perpendicular to the axial direction. 
     In other general aspects, an apparatus includes: a structure including a structure interior configured to receive target material that travels along a path; a receptacle including a volume; and a connection device between the structure and the receptacle, and configured to provide a fluid communication between the structure interior and the receptacle volume. The connection device includes: a mechanically insulating device comprising a flexible bellows extending between first and second flanges; an inner sleeve; and a shield device. The flexible bellows defines a bellows passageway that extends along an axial direction between openings of the first and second flanges. The first flange is fixed to a wall of the structure and the second flange is fixed to the receptacle. The inner sleeve is affixed to or supported by the first flange and extends within the bellows passageway in the axial direction. The inner sleeve has an outer diameter that is less than an inner diameter of the flexible bellows and defines a sleeve passageway within the bellows passageway, such that the sleeve passageway provides the fluid communication between the structure interior and the receptacle volume. The shield device is at least partly fixed to or supported by the second flange and defines an axial device opening having a diameter that is less than the inner diameter of the flexible bellows and is greater than the outer diameter of the rigid inner sleeve. 
     Implementations can include one or more of the following features. For example, the receptacle can be in fluid communication with a nozzle system of a target supply system configured to supply target material to an EUV light source. The receptacle can be a part of a target material debris collection and drain system of a drain module within a chamber of an EUV light source. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a block diagram of an apparatus including a mechanically insulating device, a rigid inner sleeve extending within a passageway of the mechanically insulating device, and a shield device configured to blocks particulates from entering a gap between the rigid inner sleeve and the mechanically insulating device; 
         FIGS.  2 A and  2 B  are block diagrams of the apparatus of  FIG.  1   , showing, respectively, translational and rotational relative motion between a first flange at a first end of the mechanically insulating device and a second flange at a second end of the mechanically insulating device; 
         FIG.  3 A  is a cutaway perspective view of an implementation of the apparatus of  FIG.  1   ; 
         FIG.  3 B  is a perspective view of a rigid inner sleeve of the apparatus of  FIG.  3 A ; 
         FIG.  3 C  is a perspective view of an implementation of a disk used in the shield device of the apparatus of  FIG.  3 A ; 
         FIG.  3 D  is a side cross-sectional view of the apparatus of  FIG.  3 A ; 
         FIG.  3 E  is a plan view along the XY plane at plane 3E-3E of  FIG.  3 D , the plan view including a disk housing, a disk, and a rigid inner sleeve of the apparatus of  FIG.  3 D ; 
         FIG.  3 F  is a side cross-sectional view showing an implementation of a section 3F of the apparatus of  FIG.  3 D ; 
         FIG.  3 G  is a side cross-sectional view showing another implementation of the section 3F of the apparatus of  FIG.  3 D ; 
         FIG.  3 H  is a perspective view of another implementation of a disk used in the shield device of the apparatus of  FIG.  3 A ; 
         FIG.  4 A  is a side cross-sectional view of the apparatus of  FIG.  3 A , showing relative motion between first and second flanges attached to the mechanically insulating device along an axial direction; 
         FIG.  4 B  is a plan view along the XY plane at plane 4B-4B of  FIG.  4 A , the plan view including a disk housing, a disk, and a rigid inner sleeve of the apparatus of  FIG.  4 A ; 
         FIG.  5 A  is a side cross-sectional view of the apparatus of  FIG.  3 A , showing relative motion between first and second flanges attached to the mechanically insulating device, the relative motion being a translation motion along a direction that is perpendicular to the axial direction; 
         FIG.  5 B  is a plan view along the XY plane at plane 5B-5B of  FIG.  5 A , the plan view including a disk housing, a disk, and a rigid inner sleeve of the apparatus of  FIG.  5 A ; 
         FIG.  6 A  is a side cross-sectional view of the apparatus of  FIG.  3 A , showing relative motion between first and second flanges attached to the mechanically insulating device, the relative motion being a rotation motion about a direction that is perpendicular to the axial direction; 
         FIG.  6 B  is a plan view along the XY plane at plane 6B-6B of  FIG.  6 A , the plan view including a disk housing, a disk, and a rigid inner sleeve of the apparatus of  FIG.  6 A ; 
         FIG.  7 A  is a side cross-sectional view of another implementation of the apparatus of  FIG.  1   , in which the shield device includes a plurality of disks seated in a disk housing; 
         FIG.  7 B  is a plan view along the XY plane at plane 7B-7B of  FIG.  7 A , the plan view including the disk housing, the disks, and a rigid inner sleeve of the apparatus of  FIG.  7 A ; 
         FIG.  7 C  is a side cross-sectional view showing an implementation of a section 7C of the apparatus of  FIG.  7 A ; 
         FIG.  8 A  is a side cross-sectional view of another implementation of the section 3F of the apparatus of  FIG.  3 D , showing motion of the rigid inner sleeve relative to a shield device that includes a single disk in a disk housing; 
         FIG.  8 B  is a side cross-sectional view of another implementation of the section 7C of the apparatus of  FIG.  7 A , showing motion of the rigid inner sleeve relative to a shield device that includes two disks in a disk housing; 
         FIG.  9 A  is a side cross-sectional view of the apparatus of  FIG.  7 A , showing relative motion between first and second flanges attached to the mechanically insulating device, the relative motion being a translation motion along a direction that is perpendicular to the axial direction; 
         FIG.  9 B  is a plan view along the XY plane at plane 9B-9B of  FIG.  9 A , the plan view including the disk housing, the disks, and the rigid inner sleeve of the apparatus of  FIG.  9 A ; 
         FIG.  10 A  is a side cross-sectional view of the apparatus of  FIG.  7 A , showing relative motion between first and second flanges attached to the mechanically insulating device, the relative motion being a rotation motion about a direction that is perpendicular to the axial direction; 
         FIG.  10 B  is a plan view along the XY plane at plane 10B-10B of  FIG.  10 A , the plan view including the disk housing, the disks, and the rigid inner sleeve of the apparatus of  FIG.  10 A ; 
         FIG.  11 A  is a side cross-sectional view of another implementation of the apparatus of  FIG.  1   , in which the apparatus includes a heating apparatus associated with the rigid inner sleeve and an inner guard associated with a second flange attached to the mechanically insulating device; 
         FIG.  11 B  is a plan view along the XY plane at plane 11B-11B of  FIG.  11 A , the plan view including the disk housing, the disk, the rigid inner sleeve, and the inner guard of the apparatus of  FIG.  11 A ; 
         FIG.  11 C  is a perspective view of an implementation of the inner guard of the apparatus of  FIG.  11 A ; 
         FIG.  12    is a block diagram of an apparatus including a structure, a receptacle, and the apparatus of  FIG.  1    acting as a connection device between the structure and the receptacle; and 
         FIG.  13    is a block diagram of an extreme ultraviolet (EUV) light source, in which the receptacle of  FIG.  12    is in fluid communication with a nozzle system of a target supply system configured to supply target material. 
     
    
    
     DESCRIPTION 
     Referring to  FIGS.  1 ,  2 A, and  2 B , an apparatus  100  is configured as a pass-through fluid device that connects a first part  105  and a second part  110 . The apparatus  100  enables relative movement between the first and second parts  105 ,  110  while maintaining the connection between the first and second parts  105 ,  110 , and while also maintaining a fluid flow path for a fluid to pass between the first and second parts  105 ,  110 . The relative movement between the first and second parts  105 ,  110  can be due to thermal expansion or contraction of one or more of the first and second parts  105 ,  110 , and vibrations and positional deviations between the first and second parts  105 ,  110 . 
     The apparatus  100  provides a flexible and mechanically adjustable pathway for the fluid path between the first and second parts  105 ,  110 . The apparatus  100  includes a mechanically insulating device  115  that includes a flexible bellows extending between a first flange  125  defining a first opening  125   o  and a second flange  130  defining a second opening  130   o . The flexible bellows  115  defines a bellows passageway  120  that extends along an axial direction B A  between the openings  125   o ,  130   o . The axial direction B A  is parallel with a Z axis of an X, Y, Z coordinate system. 
     The first flange  125  is fixed to the first part  105  and the second flange  130  is fixed to the second part  110  such that fluid is enabled to pass through the openings  125   o ,  130   o . The first and second flanges  125 ,  130  are extensions (such as a rib or a rim) that provides for strength, and for attachment to between the respective first and second part  105 ,  110  and the mechanically insulating device  115 . Moreover, the first and second flanges  125 ,  130  can be vacuum flanges that each act to provide a hermetic seal between the respective first and second part  105 ,  110  and the mechanically insulating device  115 , such seal acting to maintain the fluid within the fluid flow path. Thus, in order to achieve a vacuum seal at each vacuum flange  125 ,  130 , a gasket can be arranged at the interface between the respective first and second part  105 ,  110  and the first and second flange  125 ,  130 . The gasket can be, for example, an elastomeric O-ring placed in a groove. 
     The apparatus  100  includes a rigid inner sleeve  135  that is fixed to the first flange  125  by a mounting structure  136 . The rigid inner sleeve  135  extends along the bellows passageway  120  along the axial direction B A , and defines a sleeve passageway  137  within the bellows passageway  120 . An outer diameter OD 135  of the inner sleeve  135  is less than an inner diameter ID 115  of the flexible bellows  115 . The rigid inner sleeve  135  acts as a shield that prevents or drastically reduces a contamination of the flexible bellows  115 . In particular, the rigid inner sleeve  135  physically blocks particulates (that can be in fluid that flows between the first part  105  and the second part  110 ) from reaching the flexible bellows  115 . Specifically, the rigid inner sleeve  135  maintains particulates that travel between the first and second parts  105 ,  110  within the sleeve passageway  137  (and thus keeping such particulates separated from the flexible bellows  115 ). The rigid inner sleeve  135  also enables removal of such particulates from the sleeve passageway  137  in a manner that ensures such particulates have a reduced or minimal disruption to operation of the first and second flanges  125 ,  130  and the flexible bellows  115 . 
     In some implementations, particulates can be formed within an extreme ultraviolet (EUV) light source chamber from a target material that emits EUV light when in a plasma state (such as shown in  FIG.  13   ). The target material can be, for example, water, tin, lithium, xenon, or any material that, when converted to a plasma state, has an emission line in the EUV range. For example, the target material can be the element tin, which can be used as pure tin (Sn); as a tin compound, for example, SnBr4, SnBr2, SnH4; as a tin alloy, for example, tin-gallium alloys, tin-indium alloys, tin-indium-gallium alloys, or any combination of these alloys. 
     During operation, and without the use of the rigid inner sleeve  135 , the flexible bellows  115  would be exposed to the particulates due to the flow of fluid between the first and second parts  105 ,  110 . Such particulates include, for example, solid particles, fluid particles, and splashes of clusters of particles. Contamination of the flexible bellows  115  and the attached flanges  125 ,  130  from these particulates can have a detrimental effect on the functionality of the flexible bellows  115 ; the vacuum integrity of the flexible bellows  115 ; and the integrity of the vacuum seal or seals at least partly maintained by the flexible bellows  115 . In particular, the flexible bellows  115  is made of a flexible and thin bellows material extending along the axial direction B A , and this bellows material has a geometric configuration that includes corrugations or pleats (such as ridges or grooves). These corrugations or pleats are configured to fold and unfold to enable the relative motion between the first and second flanges  125 ,  130 . These corrugations or pleats provide functionality to the flexible bellows  115 ; for example, the expansion and contraction of the corrugations enables relative movement between the first and second parts  105 ,  110  while maintaining the connection between the first and second parts  105 ,  110 . Particulates that are deposited within the corrugations of the flexible bellows  115  can therefore compromise the ability of the flexible bellows  115  to expand and/or contract. Moreover, particulates that are deposited on the thin bellows material of the flexible bellows  115  can also corrode the thin bellows material, which therefore compromises the vacuum integrity of the flexible bellows  115 . This can lead to a vacuum leak through the thin bellows material of the flexible bellows  115 . 
     As discussed above, the outer diameter OD 135  of the inner sleeve  135  is less than the inner diameter ID 115  of the flexible bellows  115 . Moreover, the outer diameter OD 135  of the inner sleeve  135  is small enough so that a gap between the inner sleeve  135  and the flexible bellows  115  is great enough to permit the needed motion of the flexible bellows  115  and to permit the full relative motion between the first and second flanges  125 ,  130 . A difference (G) between the inner diameter ID 115  of the flexible bellows  115  and the outer diameter OD 135  of the inner sleeve  135  is given by G = ID 115  -OD 135 . This difference G can be greater than a percentage P of the inner diameter ID 115  of the flexible bellows  115 . In some implementations, the difference G is greater than about 10% of the inner diameter ID 115  of the flexible bellows  115 , or G &gt; 0.1 × ID 115 . In other implementations, the difference G is greater than about 20% of the inner diameter ID 115  of the flexible bellows  115 , or G &gt; 0.2 × ID 115 . In other implementations, the difference G is greater than about 30% of the inner diameter ID 115  of the flexible bellows  115 , or G &gt; 0.3 × ID 115 . 
     As shown in  FIG.  2 A , the relative motion between the first and second flanges  125 ,  130  can be a translation motion along one or more directions that are perpendicular to the axial direction B A . While translation along the X axis is shown in  FIG.  2 A , such translation motion can be along any direction in the XY plane. As shown in  FIG.  2 B , the relative motion between the first and second flanges  125 ,  130 , can be a rotation motion about one or more directions that are perpendicular to the axial direction B A . While rotation about the Y axis is shown in  FIG.  2 B , such rotational motion can be about any direction in the XY plane. 
     The apparatus  100  further includes a shield device  140  positioned within the gap between the inner sleeve  135  and the flexible bellows  115 . The shield device  140  acts as a shield or cover that blocks particulates (such as solid particles, fluid particles, and splashes or splash particles) from entering the gap between the rigid inner sleeve  135  and the flexible bellows  115 . Moreover, the shield device  140  is able to perform the function of preventing contamination while still maintaining the separation between the inner sleeve  135  and the flexible bellows  115  and not restricting motion of the rigid inner sleeve  135 . 
     Referring to  FIG.  3 A , an implementation  300  of the apparatus  100  is shown. The apparatus  300  includes a flexible bellows  315  extending between a first flange  325  defining a first opening  325   o  and a second flange  330  defining a second opening  330   o . The first flange  325  can be fixed to a structure or part such as the first part  105  ( FIG.  1   ), and the second flange  330  can be fixed to another structure or part such as the second part  110  ( FIG.  1   ). In this way, a vacuum seal can be formed between the first flange  325  and the first part  105  and a vacuum seal can be formed between the second flange  330  and the second part  110 . The flexible bellows  315  is an implementation of the mechanically insulating device  115  ( FIG.  1   ). The apparatus  300  also include a rigid inner sleeve  335  fixed to the first flange  325  and a shield device  340  at least partly fixed or supported by the second flange  330 . 
     The flexible bellows  315  defines a bellows passageway  320  that extends along an axial direction B A  between the first opening  325   o  and the second opening  330   o . The axial direction B A  is parallel with the Z axis. The flexible bellows  315  includes a first end  317 , a second end  319 , and a corrugated portion  316  made of a bellows material and geometrically shaped to allow for the functionality of the flexible bellows  315  including expansion and contraction. The first end  317  is fixed to the first flange  325  and connects the corrugated portion  316  of the flexible bellows  315  to the first flange  325 . The second end  319  is fixed to the shield device  340  and connects the corrugated portion  316  of the flexible bellows  315  to the shield device  340 . The corrugated portion  316  includes pleats  318  that are configured to fold and unfold enabling the flexible bellows  315  to expand and contract generally along the axial direction B A . This functionality of the flexible bellows  315  permits for relative movement between the first and second flanges  325 ,  330  that can be caused by thermal expansion or contraction of one or more of the structures fixed to each of the flanges  325 ,  330 , and vibrations and positional deviations between the structures fixed to each of the flanges  325 ,  330 . The relative movement is discussed with reference to  FIGS.  4 A- 6 B . 
     The rigid inner sleeve  335  extends through the bellows passageway  320  along the axial direction B A . The rigid inner sleeve  335  defines a sleeve passageway  337  within the bellows passageway  320 . The rigid inner sleeve  335  is fixed to the first flange  325  by a mounting structure  336 . The mounting structure  336  is coupled to the first end  317  of the flexible bellows  315 , and the first end  317  is directly joined to the first flange  325 . With additional reference to  FIG.  3 B , the rigid inner sleeve  335  is cylindrically shaped with a circular cross-section taken in the XY plane. The rigid inner sleeve  335  is made of a rigid material that is not reactive with fluid that passes through the bellows passageway  320 . For example, the rigid inner sleeve  335  can be made of a metal such as molybdenum, aluminum or, copper or other suitable materials such as but not limited to aluminum oxide, diamond, and graphite. The rigid inner sleeve  335  can have an inner surface  338  (which defines the sleeve passageways  337 ) that is generally smooth. 
     Referring again to  FIG.  3 A , the shield device  340  is at least partly fixed to or supported by the second flange  330 . The shield device  340  defines an axial device opening  340   o  in fluid communication with the second opening  330   o . The shield device  340  is positioned at the free end of the rigid inner sleeve  335  (the end nearest the second flange  330 ) so that the free end of the rigid inner sleeve  335  extends through the axial device opening  340   o . 
     The shield device  340  includes at least one movable disk  344  and a disk housing  342  configured to retain the disk  344 . The disk housing  342  includes a first side  346   a  and a second side  346   b . The first side  346   a  of the shield device  340  is fixed to the second end  319  of the flexible bellows  340 , and the second side  346   b  is fixed to the second flange  330  by a mounting region  327 . The fixing can be by way of a vacuum seal. In particular, the first side  346   a  can be vacuum sealed to the second end  319  of the flexible bellows  340  and the second side  346   b  can be vacuum sealed to the second flange  330 . 
     Referring specifically to  FIGS.  3 D and  3 F , so as not to obstruct fluid flow through the apparatus  300  and to enable relative motion between the first and second flanges  325 ,  330 , the disk housing  342  is annular in shape and thus defines the axial device opening  340   o  through which the rigid inner sleeve  335  can pass. The axial device opening  340   o  is defined by an inner diameter ID 342  that is on the order of or about the same extent as an inner diameter ID 315  of the flexible bellows  315 . The inner diameters ID 342  and ID 315  can be about the same size as the diameter of the opening  330   o . The disk housing  342  has an annular radius AR 342  ( FIG.  3 E ), which is given by one half of the distance between an outer circumferential edge (defining the outer diameter OD 342 ) of the disk housing  342  and an inner circumferential edge (defining an inner diameter ID 342  of the axial opening  340   o ). 
     Referring to  FIGS.  3 C- 3 F , the disk  344  has a generally flat shape along the axial direction B A  when inserted into the disk housing  342 . The disk  344  is retained in the disk housing  342  so that the disk  344  is able to move along a direction within the XY plane. 
     In the implementation shown in  FIGS.  3 A- 3 F , in which only one disk  344  is retained in the disk housing  342 , an outer diameter OD 344  of the disk  344  is greater than the inner diameter ID 342  of the disk housing  342  so that the disk  344  does not become removed from or askew within the disk housing  342 , which could cause the disk  344  to become jammed and unable to move. Moreover, to enable the disk  344  to move freely in the XY plane and to move far enough within the XY plane to enable the full range of relative motion between the first and second flanges  325 ,  330 , the outer diameter OD 344  of the disk  344  should be less than the outer diameter OD 342  of the disk housing  342 . The larger the difference between the outer diameter OD 342  of the disk housing  342  and the outer diameter OD 344  of the disk  344 , the larger the range of motion of the disk  344  within the XY plane. 
     The disk  344  is annular in shape and thus defines a central opening  345  through which the rigid inner sleeve  335  can pass. To enable the rigid inner sleeve  335  to pass through the central opening  345 , the diameter D 345  of the central opening  345  is larger than the outer diameter OD 335  of the rigid inner sleeve  335 . An annular radius AR 344  of the disk  344  is given by one half of the distance between an outer circumferential edge  343  (defining the outer diameter OD 344 ) of the disk  344  and an inner circumferential edge  341  (defining diameter D 345  of the central opening  345 ). 
     Referring to  FIGS.  3 C,  3 D, and  3 F , the disk  344  is defined by a thickness T 344  taken along the Z axis, which is parallel with the axial direction B A  when the disk  344  and the shield device  340  are attached within the apparatus  300 . This thickness T 344  is less than a thickness T 342  of an interior cavity  339  of the disk housing  342  taken along the Z axis. The difference between the thickness T 342  of the interior cavity  339  of the disk housing  342  and the thickness T 344  of the disk  344  should be great enough to enable the free movement of the disk  344  along the XY plane within the interior cavity  339  of the disk housing  342 . Additionally, the difference between the thickness T 342  of the interior cavity  339  of the disk housing  342  and the thickness T 344  of the disk  344  should be small enough to at least partly constrain the disk  344  from excessive motion along the Z axis when the disk  344  is inside the disk housing  342 . A notable gap between the disk housing  342  and the disk  344  is shown in  FIGS.  3 A,  3 D, and  3 F  to facilitate clarity in the drawings; nevertheless, it is possible for the disk  344  to be in contact with or much closer to the disk housing  342 , as shown in  FIG.  3 G . 
     Referring to  FIG.  3 H , in some implementations, the disk  344  includes a slit  347  that extends radially between the outer edge  343  (defining the outer diameter OD 344 ) of the disk  344  and the inner edge  341  (defining the central opening  345  of the disk  344 ). In other words, the disk  344  is cut from the outer edge  343  of the disk  344  to the central opening  345  along the radial direction such that the slit  347  is formed. The slit  347  is formed by a first radial edge  348   a  and a second radial edge  348   b  of the disk  344 . The first radial edge  348   a  and the second radial edge  348   b  can be moved relative to each other along the Z direction by bending the disk  344  to thereby form a gap between the first and second radial edges  348   a ,  348   b  extending along the Z direction. For example, the thickness T 344  of the disk  344  can be small enough that the disk  344  is flexible and can bend to allow the first radial edge  348   a  to move relative to the second radial edge  348   b  in the Z direction. 
     The slit  347  allows the disk  344  to be installed within the interior cavity  339  of the disk housing  342 . The gap is formed between the first radial edge  348   a  and the second radial edge  348   b  in the Z direction when the first and second radial edges  348   a ,  348   b  are moved relative to each other. The gap between the first and second radial edge  348   a ,  348   b  allows a portion of the disk  344  including the first radial edge  348   a  to be installed in the interior cavity  339  of the disk housing  342  before the remaining portion of the disk  344  including the second radial edge  348   b  is installed into the disk housing  342 . Specifically, the first radial edge  348   a  can be passed through the opening  330   o  of the second flange  330  and through the axial device opening  340   o  to install the portion of the disk  344  including the first radial edge  348   a  into the interior cavity  339  of the disk housing  342 . The disk  344  can then be rotated about the axial direction B A  to install the remaining portion of the disk  344  including the second radial edge  348   b  into the interior cavity  339  of the disk housing  342 . In this way, the slit  347  allows the disk  344  that is defined by the outer diameter OD 344  that is greater than the inner diameter ID 342  of the disk housing  342  to be installed within the disk housing  342 . 
     The shield device  340  including the disk  344  and the disk housing  342  can be made of material that is rigid and not reactive to the fluid passing through the apparatus  300 . For example, the disk  344  and the disk housing  342  can be made of a metal such as stainless steel. In implementations of the disk  344  that include the slit  347 , the disk  344  can be made of a metal that is pliable and bends and returns to its original shape after forces are applied to the disk  344  to deform the disk  344 . Thus, the disk  344  can be made of stainless steel that is defined by a thickness T 344  that is much smaller than the outer diameter OD 344 . 
     Additionally, one or more of the disk  344  and the disk housing  342  (of the shield device  340 ) can also include a coating configured to prevent particulates from contaminating the shield device  340 . For example, the shield device  340  coating can be configured to repel fluid particles to prevent the fluid particles from accumulating on the shield device  340  and to prevent solid particles from sticking to the shield device  340 . The shield device  340  coating can be, for example, a nitride such as a metal nitride or a metalloid nitride. The coating on the disk  344  and/or the disk housing  342  can also act to prevent corrosion of the underlying material (which can be stainless steel), such corrosion being caused by contamination by the particulates. 
     If the particulates are formed from target material with a chamber of an EUV light source, then the shield device  340  coating can be selected so as to be compatible with and/or to repel the target material. 
     The rigid inner sleeve  335  can also include a coating configured to prevent particulates  328  from contaminating one or more of the shield device  340  and the rigid inner sleeve  335  during operation. As discussed above, particulates  328  can include one or more of solid particles, fluid particles, and splashes of the fluid that pass through the sleeve passageway  337 . For example, the rigid inner sleeve  335  coating can be configured to repel the fluid particles to prevent the fluid particles from accumulating on the shield device  340  and the rigid inner sleeve  335 . The rigid inner sleeve  335  coating can be, for example, a metal nitride or a silicon nitride. If the particulates are formed from target material with a chamber of an EUV light source, then the rigid inner sleeve  335  coating can be selected so as to be compatible with and/or to repel the target material. 
     In particular, and with reference to  FIG.  3 F , the rigid inner sleeve  335  coating can be configured to repel the particulates  328  (such as fluid particles) along a direction that is parallel to the axial direction B A  or away from the shield device  340 . In particular, when a fluid propagates through the sleeve passageway  337 , the fluid particles that detach from the coating on the smooth inner surface  338  detach in a manner such that their propagation direction is parallel with the axial direction B A  or away from the components (the disk  344  and the disk housing  342 ) of the shield device  340 , as shown in  FIG.  3 F . The rigid inner sleeve  335  coating can also be configured to prevent the solid particles from sticking to the shield device  340  and the rigid inner sleeve  335 . As another example, the rigid inner sleeve  335  coating can be configured to prevent corrosion of an exterior surface (such as a surface of the disk  344  or the disk housing  342 ) of the shield device  340  that is caused by the contamination of the particulates. 
     In operation, the rigid inner sleeve  335  is configured to physically block particulates from reaching the flexible bellows  315  by maintaining particulates that travel between structures or parts through the apparatus  300  within the sleeve passageway  337  and separated from the flexible bellows  315 . As described above, the functionality of the flexible bellows  315  permits relative movement between the first and second flanges  325 ,  330  that can be caused by thermal expansion or contraction of one or more of the structures fixed to each of the flanges  325 ,  330 , and vibrations and positional deviations between the structures fixed to each of the flanges  325 ,  330 . The upper end of the rigid inner sleeve  335  that is fixed to the first flange  325  moves with the first flange  325  and relative to the second flange  330  when each of the flanges  325 ,  330  moves relative to each other. In this way, as particulates  328  travel through the sleeve passageway  237  and each of the flanges  325 ,  330  moves relative to each other, the rigid inner sleeve  335  continues to block the particulates  328  from reaching the flexible bellows  315 . 
     Furthermore, the lower end of the rigid inner sleeve  335  that is near the second flange  330  extends below the shield device  340  to physically block particulates  328  from contaminating the shield device  340 . In addition, the shield device  340  prevents particulates  328  from traveling into the region between the flexible bellows  315  and the rigid inner sleeve  335  through an opening defined between the lower end of the rigid inner sleeve  335  (that is nearest to the second flange  330 ) and the second flange  330 . Specifically, when the rigid inner sleeve  335  moves with the first flange  325  and relative to the second flange  330 , the disk  344  also moves with the lower portion of the rigid inner sleeve  335  (that is near the second flange  330 ) relative to the second flange  330  and blocks particulates  328  from traveling into the opening  320  between the flexible bellows  315  and the rigid inner sleeve  335 . As such, both of the rigid inner sleeve  335  and the shield device  340  physically block the particulates  328  from reaching and contaminating the flexible bellows  315  during operation. Details are provided next. 
     During operation, as discussed above with reference to  FIGS.  2 A and  2 B , the relative movement between the first and second flanges  325 ,  330  can include linear motion along the axial direction B A , translational motion along one or more directions that are perpendicular to the axial direction B A , and rotational motion about one or more directions that are perpendicular to the axial direction B A . The shield device  340  enables this relative movement between the first and second flanges  325 ,  330  while preventing the particulates  328  from entering the region between the rigid inner sleeve  335  and the flexible bellow  315  to thereby contaminate the flexible bellows  315 . 
     Referring to  FIGS.  4 A and  4 B , the first and second flanges  325 ,  330  move relative to each other in a linear motion along the axial direction B A . For example, the first flange  325  can move along the axial direction B A  towards the second flange  330 . The flexible bellows  315  expands and contracts along the axial direction B A  allowing the first and second flanges  325 ,  330  to move relative to each other. As described above, the flexible bellows  315  expands and contracts by the folding and unfolding of the pleats  318  in the corrugated portion  316  of the flexible bellows  315 . For example, the flexible bellows  315  contracts by the folding of the pleats  318  when the first and second flanges  325 ,  330  move towards each other along the axial direction B A  and expands by the unfolding of the pleats  318  when the first and second flanges  325 ,  330  move away from each other along the axial direction B A . Because the rigid inner sleeve  335  is fixed to the first flange  335 , the rigid inner sleeve  335  moves with the first flange  325  and relative to the second flange  330  along the Z direction. For example, the rigid inner sleeve  335  can move with the first flange  325  along the Z direction towards the second flange  330 . 
     The shield device  340  enables the relative linear motion between the first and second flanges  325 ,  330  along the axial direction B A . Specifically, the rigid inner sleeve  335  that moves with the first flange  325  is enabled to move along the axial direction B A  through the central opening  345  of the disk  344 . Because the outer diameter OD 335  of the rigid inner sleeve  335  is smaller than the diameter D 345  of the central opening  345  of the disk  344 , the rigid inner sleeve  335  is able to freely move along the Z direction relative to the disk  344 . In this way, the shield device  340  enables the relative linear motion of the first and second flanges  325 ,  330  along the axial direction B A  by allowing the rigid inner sleeve  335  to also move with the axial motion relative motion between the first flange  325  and the second flange  330 . Additionally, as the rigid inner sleeve  335  moves relative to the second flange  330  in the axial direction B A , the disk  344  continues to block particulates  328  from traveling into the region between the rigid inner sleeve  335  and the flexible bellows  315 . Thus, the shield device  340  prevents the particulates  328  from contaminating the flexible bellows  315  when the first and second flanges  325 ,  330  move relative to each other along the axial direction B A . 
     Referring to  FIGS.  5 A and  5 B , the first and second flanges  325 ,  330  move relative to each other in a translational motion along the X direction that is perpendicular to the axial direction B A . For example, as shown in  FIG.  5 A , the first flange  325  can move along the -X direction relative to the second flange  330 . A portion or side of the flexible bellows  315  expands generally along the axial direction B A  while another portion or side of the flexible bellows  315  contracts, thus allowing the first and second flanges  325 ,  330  to move relative to each other. For example, a corrugated portion  316   a  of the flexible bellows  315  expands by the unfolding of the pleats  318  while a corrugated portion  316   b  of the flexible bellows  315  contracts by folding the pleats  318  when the first flange  325  moves along the -X direction relative to the second flange  330 . Because the rigid inner sleeve  335  is fixed to the first flange  335 , the rigid inner sleeve  335  moves with the first flange  325  relative to the second flange  330  along the -X direction. For example, the rigid inner sleeve  335  can move with the first flange  325  along the -X direction relative to the second flange  330 . 
     The shield device  340  enables and facilitates the relative translational motion between the first and second flanges  325 ,  330  along the XY plane. Specifically, because the disk  344  is enabled to move along the X direction (and in the XY plane) within the interior cavity  339  of the disk housing  342 , the rigid inner sleeve  335  that moves with the first flange  325  is also enabled to move along the X direction while remaining within the opening  345  of the disk  344 . In other words, the disk  344  does not prevent or constrain the rigid inner sleeve  335  from moving in the X direction. Thus, as the first flange  325  and the rigid inner sleeve  335  move along the X direction relative to the second flange  330 , the disk  344  is also prompted to move along the X direction by the movement of the rigid inner sleeve  335 . In this way, the shield device  340  enables the relative translational motion of the first and second flanges  325 ,  330  along the X direction that is perpendicular to the axial direction B A  by allowing the rigid inner sleeve  335  to also move with the first flange  325 . 
     Additionally, as the rigid inner sleeve  335  moves relative to the second flange  330  in the X direction, the disk  344  continues to block particulates  328  from traveling into the region between the rigid inner sleeve  335  and the flexible bellows  315 . Because the disk  344  moves with the rigid inner sleeve  335  and the first flange  325  in the -X direction relative to the second flange  330 , the disk  344  continues to radially span the gap between the rigid inner sleeve  335  and the flexible bellows  315 . Thus, the shield device  340  prevents the particulates  328  from contaminating the flexible bellows  315  when the first and second flanges  325 ,  330  move relative to each other translationally along the XY plane. In other examples, the shield device  340  can similarly enable relative translational motion of the first and second flanges  325 ,  330  along any direction that is perpendicular to the axial direction B A  such as, for example, the Y direction or a direction in the XY plane. In these examples, the shield device  340  prevents the particulates  328  from contaminating the flexible bellows  315  in the same manner as described above. 
     Referring to  FIGS.  6 A and  6 B , the first and second flanges  325 ,  330  move relative to each other in a rotational motion about a direction (such as the Y direction) that is perpendicular to the axial direction B A . For example, the first flange  325  can rotate about the Y direction relative to the second flange  330 . The flexible bellows  315  expands generally along the axial direction B A  at the corrugated portion  316   a  of the flexible bellows  315  and contracts generally along the axial direction B A  at the corrugated portion  316   b  of the flexible bellows  315  allowing the first and second flanges  325 ,  330  to rotate relative to each other. For example, the flexible bellows  315  expands by the unfolding of the pleats  318  at the portion  316   a  of the flexible bellows  315  and contracts by the folding of the pleats  318  at the portion  316   b  of the flexible bellows  315 . Because the rigid inner sleeve  335  is fixed to the first flange  335 , the rigid inner sleeve  335  rotates with the first flange  325  relative to the second flange  330  about the Y direction. For example, the rigid inner sleeve  335  can rotate with the first flange  325  about the Y direction such that the lower portion of the rigid inner sleeve  335  (that is near the second flange  330 ) is rotated (and also translated) relative to the second flange  330 . 
     The shield device  340  enables a tilting between the first and second flanges  325 ,  330 , which involves the relative rotational motion between the first and second flanges  325 ,  330  about the direction perpendicular to the axial direction B A  (such as the Y direction in this example). Specifically, because the disk  344  is enabled to move along the XY plane within the interior cavity  339  of the disk housing  342 , the lower portion of the rigid inner sleeve  335  that is moved by the rotation of the first flange  325  about the Y direction is also enabled to rotate. In other words, the disk  344  does not prevent the lower portion of the rigid inner sleeve  335  from rotating. Thus, as the first flange  325  and the rigid inner sleeve  335  rotate about the Y direction relative to the second flange  330 , the disk  344  is also prompted to move along the X direction by the movement of the lower portion of the rigid inner sleeve  335 . In this way, the shield device  340  enables the relative rotational motion of the first and second flanges  325 ,  330  about the Y direction that is perpendicular to the axial direction B A  by allowing the rigid inner sleeve  335  to also move with the first flange  325 . 
     Additionally, as the lower portion of the rigid inner sleeve  335  rotates relative to the second flange  330 , the disk  344  continues to block particulates  328  from traveling into the region between the rigid inner sleeve  335  and the flexible bellows  315 . Because the disk  344  moves with the lower portion of the rigid inner sleeve  335  in the X direction, the disk  344  continues to radially span the gap between the rigid inner sleeve  335  and the flexible bellows  315 . Thus, the shield device  340  prevents the particulates  328  from contaminating the flexible bellows  315  when the first and second flanges  325 ,  330  are rotated relative to each other about the Y direction. In other examples, the shield device  340  can similarly enable relative rotational motion of the first and second flanges  325 ,  330  about any other direction that is perpendicular to the axial direction B A  such as, for example, about the X direction or about a direction in the XY plane. In these examples, the shield device  340  prevents the particulates  328  from contaminating the flexible bellows  315  in the same manner as described above. 
     Referring to  FIGS.  7 A and  7 B , an apparatus  700  is designed similarly to the apparatus  300  except that the apparatus  700  includes a plurality (or stack)  744  of disks  744   a ,  744   b ,  744   c  positioned within an interior cavity  739  of a disk housing  742 . The disks  744   a ,  744   b ,  744   c  are layered or stacked adjacently to each other along the Z direction. Each of the disks  744   a ,  744   b ,  744   c  in the stack  744  is designed similarly to the disk  344  in that each disk  744   a ,  744   b ,  744   c  includes a respective central opening  745   a ,  745   b ,  745   c  that is large enough to accommodate the inner rigid sleeve  735 . Thus, a diameter D 745a , D 745b , D 745c  of each central opening  745   a ,  745   b ,  745   c  is greater than an outer diameter OD 735  of the rigid inner sleeve  735 . 
     In some implementations, at least one of the disks (for example, disk  744   b ) has an outer diameter OD 744b  that is different from an outer diameter of each other disk (such as outer diameter OD 744a  and OD 744c  of respective disks  744   a  and  744   c ). In still further implementations, at least one disk (such as disk  744   a ) has an outer diameter OD 744a  that is equal to the outer diameter OD 744c  of another disk (such as disk  744   c ) and an inner diameter D 745a  that is equal to the inner diameter D 745c  of the other disk  744   c . In these implementations, the disks  744   a  and  744   c  have the same annular radius. 
     The sum of the thicknesses T of each disk  744   a ,  744   b ,  744   c  taken along the axial direction B A  is less than an extent of the interior cavity  739  along the axial direction B A  to enable all of the disks  744   a ,  744   b ,  744   c  to fit within the interior cavity  739 . Moreover, one or more of the disks  744   a ,  744   b ,  744   c  can include a slit (such as the slit  347  in disk  344  discussed above) that extends radially between the outer edge (defining the outer diameter OD) of that disk  744   a ,  744   b ,  744   c  and the inner edge (defining the central opening  745   a ,  745   b ,  745   c  of that disk). Such slit can function similarly to the function of the slit  347  to enable each disk  744   a ,  744   b ,  744   c  to be installed within the interior cavity  739  of the disk housing  742 . 
     In some implementations, one of the disks in the disk stack  744  is a small disk, such as disk  744   b . This means that the disk  744   b  has an outer diameter OD 744b  that is less than a sum of an inner diameter ID 742  of the disk housing  742  plus an annular radius AR 742  of the disk housing  742  ( FIGS.  7 B and  7 C ). In this situation, the small disk  744   b  could be dislodged from or askew within the interior cavity  739 , which could cause the disk  744   b  to be accidentally jammed and prevented from moving within the interior cavity  739 . Accordingly, the disk  744   b  is placed between (sandwiched between) two large disks  744   a ,  744   c , such large disks  744   a ,  744   c  each have respective outer diameters OD 744a , OD 744c  that are greater than the sum of the inner diameter ID 742  of the disk housing  742  plus the annular radius AR 742  of the disk housing  742  ( FIGS.  7 B and  7 C ). 
     In general, and with reference to  FIGS.  8 A and  8 B , the use of a stack or plurality of disks of different inner and outer diameters, such as shown in  FIG.  8 B , can lead to an improvement in compactness of the disk housing and also facilitates installation of the disks through the opening  330   o  of the second flange  330  when compared with just using one disk  344 , such as used in the apparatus  300  and as shown in closer view in  FIG.  8 A . Specifically,  FIG.  8 A  shows that the annular radius AR 342  of the disk housing  342  (in which a single disk  344  is placed) is substantially larger than an annular radius AR 842  of disk housing  842 , in which two disks  844   a ,  844   b  of a stack  844  are placed. Additionally, the overall extent of the two disks  844   a ,  844   b  is given by their outer diameters and this overall extent is much smaller than the outer diameter OD 344  of the disk  344 . Nevertheless, because the inner diameter ID 842  of the disk housing  842  is the same as the inner diameter ID 342  of the disk housing  342 , it is easier to install the disks  844   a ,  844   b  in the interior cavity of the disk housing  842 . 
     In general, for a disk stack such as the disk stack  744  or the disk stack  844 , the inner and outer diameters of each disk can be chosen such that the disks in each stack overlap in all possible positions of the rigid inner sleeve  735  and also still cover the gap between the rigid inner sleeve  735  and the flexible bellows  715 . In a most compact implementation, all of the disks in a disk stack have the same annular radius and the inner diameter of the nth disk is slightly smaller than the outer diameter of the (n-1)th disk, where n=1 denotes the disk with the smallest inner diameter that is slightly larger than the outer diameter of the rigid inner sleeve  735 . 
     Referring to  FIGS.  9 A and  9 B , a relative translational motion between the first and second flanges  325 ,  330  is shown with reference to the apparatus  700 . The shield device  740  enables and facilitates the relative translational motion between the first and second flanges  325 ,  330  along the XY plane. Specifically, the small disk  744   b , which hugs the rigid inner sleeve  735 , moves with the rigid inner sleeve  735  along the -X direction. Moreover, the large disks  744   a ,  744   c  also move when engaged by the rigid inner sleeve  735 . Because the large disks  744   a ,  744   c  each have respective outer diameters OD 744a , OD 744c  that are greater than the sum of the inner diameter ID 742  of the disk housing  742  plus the annular radius AR 742  of the disk housing  742  ( FIGS.  7 B and  7 C ), the small disk  744   b  is prevented from being dislodged from the interior cavity  739  of the shield device  740 . 
     Additionally, as the rigid inner sleeve  735  moves relative to the second flange  330  in the X direction, the disk stack  744  continues to block particulates  328  from traveling into the region between the rigid inner sleeve  735  and the flexible bellows  715 . Because the disks of the disk stack  744  move with the rigid inner sleeve  735  and the first flange  725  in the -X direction relative to the second flange  330 , one or more of the disks  744   a ,  744   b ,  744   c  continues to radially span the gap between the rigid inner sleeve  735  and the flexible bellows  715 . Thus, the shield device  740  prevents the particulates  328  from contaminating the flexible bellows  715  when the first and second flanges  325 ,  330  move relative to each other translationally along the XY plane. In other examples, as discussed above, the shield device  740  enables relative translational motion of the first and second flanges  325 ,  330  along any direction that is perpendicular to the axial direction B A  such as, for example, the Y direction or a direction in the XY plane. In these examples, the shield device  740  prevents the particulates  328  from contaminating the flexible bellows  715  in the same manner as described above. 
     Referring to  FIGS.  10 A and  10 B , a relative rotational motion between the first and second flanges  325 ,  330  is shown with reference to the apparatus  700 . The first and second flanges  325 ,  330  move relative to each other in a rotational motion about a direction (such as the Y direction) that is perpendicular to the axial direction B A . The flexible bellows  715  expands and contracts as discussed with reference to the flexible bellows  315  of  FIG.  6 A . Because the rigid inner sleeve  735  is fixed to the first flange  335 , the rigid inner sleeve  735  rotates with the first flange  325  relative to the second flange  330  about the Y direction. 
     The shield device  740  enables the relative rotational motion between the first and second flanges  325 ,  330  about the direction perpendicular to the axial direction B A  (such as the Y direction in this example). Specifically, the small disk  744   b  moves along the XY plane within the interior cavity  739  of the disk housing  742  as the rigid inner sleeve  735  is rotated. Specifically, the small disk  744   b , which hugs the rigid inner sleeve  735 , moves along the -X direction as the rigid inner sleeve  735  is rotated. Moreover, the large disks  744   a ,  744   c  also move when engaged by the rigid inner sleeve  735 . Because the large disks  744   a ,  744   c  each have respective outer diameters OD 744a , OD 744c  that are greater than the sum of the inner diameter ID 742  of the disk housing  742  plus the annular radius AR 742  of the disk housing  742  ( FIGS.  7 B and  7 C ), the small disk  744   b  is prevented from being dislodged from the interior cavity  739  of the shield device  740 . 
     Additionally, as the lower portion of the rigid inner sleeve  735  rotates relative to the second flange  330 , the disk stack  744  continues to block particulates  328  from traveling into the region between the rigid inner sleeve  735  and the flexible bellows  715 . 
     Referring to  FIGS.  11 A and  11 B , an apparatus  1100  is designed similarly to the apparatus  300  except that the apparatus  1100  includes a heating apparatus  1151  and an inner guard  1153 . The heating apparatus  1151  is configured to adjust and/or regulate a temperature of the rigid inner sleeve  335 . The heating apparatus  1151  is in direct thermal communication with an outer surface 335 s of the rigid inner sleeve  335  to adjust or control the temperature of the rigid inner sleeve  335  by thermal conduction. The heating apparatus  1151  is not in direct thermal communication with the flexible bellows  315 . This means that the flexible bellows  315  is not substantially thermally affected by adjustments made by the heating apparatus  1151 . For example, the flexible bellows  315  may be positioned farther away from the heating apparatus  1151  or the flexible bellows  315  may be made of a material having a reduced thermal conductivity. 
     The heating apparatus  1151  can include a plurality of discrete heating elements positioned at various positions relative to the outer surface 335 s of the rigid inner sleeve  335  or can be a single heating element. By heating the outer surface 335 s of the rigid inner sleeve  335 , the heating apparatus  1151  also heats the sleeve passageway  337  such that the fluid that passes through the sleeve passageway  337  is heated during operation. This allows the fluid that passes through the apparatus  1100  to be transformed into or maintained in a melted, fluid, or molten state in which the fluid is able to flow. The heating also provides for melting or vaporizing any particles or other materials that contact the inner surface of rigid inner sleeve  335 , such that they may be transported away with the fluid flow. 
     As described above, the rigid inner sleeve  335  is made of a rigid material that is not reactive with fluid that passes through the sleeve passageway  337 . In the example of  FIG.  11 A , the rigid inner sleeve  335  can be made of a metal with a high thermal conductivity such that changes in temperature applied by the heating apparatus  1151  are efficiently conveyed to the rigid inner sleeve  335 . For example, the rigid inner sleeve  335  can be made of a metal such as molybdenum, aluminum or copper, or other suitable materials such as aluminum oxide, diamond, or graphite. As described above, the rigid inner sleeve  335  also includes a coating configured to prevent the particulates  328  from contaminating one or more of the shield device  340  and the rigid inner sleeve  335 . For example, the rigid inner sleeve  335  coating can be a metal nitride, a metal oxide, or a silicon nitride. 
     The inner guard  1153  extends through the opening  330   o  of the second flange  330  along the axial direction B A . With additional reference to  FIG.  11 C , the inner guard  1153  defines an inner guard passageway  1152  within the opening  330   o . The inner guard  1153  is fixed to the second flange  330  by a mounting structure  1154 . The inner guard  1153  is cylindrically shaped with a circular cross-section taken in the XY plane. The inner guard  1153  can have an inner surface  1155  (which defines the inner guard passageway  1152 ) that is generally smooth. The inner guard  1153  is made of a rigid material that is not reactive with fluid that passes through the bellows passageway  320 . Thus, the inner guard  1153  can be made of a metal that includes a coating configured to prevent the particulates  328  from contaminating the inner guard  1153 . For example, the coating can be metal nitride. If the particulates are formed from target material with a chamber of an EUV light source, then the inner guard  1153  coating can be selected so as to be compatible with and/or to repel the target material. 
     The distance between an outer diameter OD 1153  of the inner guard  1153  and the inner diameter of the second flange  330  is small enough to reduce an amount of the particulates  328  from contaminating the second flange  330 . Specifically, the distance between an outer diameter OD 1153  of the inner guard  1153  and the inner diameter of the second flange  330  is configured to reduce the amount of particulates  328  from contaminating the second flange  330  at least in part because particles are repelled from the surfaces of the inner guard  1153  and the second flange  330 . As described above, the particulates  328  can include solid particles and fluid particles. The inner guard  1153  coating is configured to repel the fluid particles to prevent the fluid particles from accumulating on the inner guard  1153  and prevent the solid particles from sticking to the inner guard  1153 . 
     Referring to  FIG.  12   , in some implementations, the apparatus  100  can be implemented as a connection device  1200  in an apparatus  1260 . The apparatus  1260  includes, as the first part  105 , a structure  1205  defining a structure interior  1263  configured to receive target material that travels along a path, and, as the second part  110 , a receptacle  1210  defining a fluid volume  1265 . The connection device  1200  is positioned between the structure  1205  and the receptacle  1210 , and is configured to provide a fluid communication between the structure interior  1263  and the receptacle volume  1265 . The first flange  325  is fixed to a wall of the structure  1205  and the second flange  330  is fixed to a wall of the receptacle  1210 . 
     In some implementations, the receptacle  1210  is in fluid communication with a nozzle system of a target supply system configured to supply target material to an EUV light source, such as within a target material supply system  1375  of  FIG.  13   . In other implementations, the receptacle  1210  is a part of a target material debris collection and drain system of a drain module within a chamber of an EUV light source, such as a drain module  1364  shown in  FIG.  13   . 
     The apparatus  1260  (including the connection device  1200 ) can be implemented in an extreme ultraviolet (EUV) light source. Referring to  FIG.  13   , an EUV light source  1370  is shown. The EUV light source  1370  includes a chamber  1372  defining an interior  1373 . The EUV light source  1370  includes a target material supply system  1375  including a droplet generator  1376  configured to produce a stream of targets  1377 . The targets  1377  include a target material that emits EUV light when in a plasma state. The target material can be, for example, water, tin, lithium, xenon, or any material that, when converted to a plasma state, has an emission line in the EUV range. For example, the target material can be the element tin, which can be used as pure tin (Sn); as a tin compound, for example, SnBr4, SnBr2, SnH4; as a tin alloy, for example, tin-gallium alloys, tin-indium alloys, tin-indium-gallium alloys, or any combination of these alloys. 
     The targets  1377  are directed toward a target location  1378 . One or more amplified light beams  1379  are also directed to the target location  1378 . The interaction between an amplified light beam  1379  and the target material within the targets  1377  (at the target location  1378 ) produces plasma that emits EUV light or radiation  1380 . A light collector  1382  collects and directs collected EUV light  1380  toward an optical apparatus  1384 . The optical apparatus  1384  can be a lithography exposure apparatus, which uses this EUV light  1380  to create a pattern on a wafer, such as, using any number of process steps, which can be one or more of a combination of process steps such as etching, deposition, and lithography processes with a different mask to create a pattern of openings (such as grooves, channels, or holes) in the material of the wafer or in materials deposited on the wafer. 
     The apparatus  1260  is retained at a wall  1369  of the chamber  1372 . The structure  1205  of the apparatus  1260  is designed as a structure  1305  having a structure passageway 1305p configured to receive targets  1377  (or the target material remaining from the targets  1377 ) that travel along a target material path Ptm. In this example, the structure  1305  is arranged at a location of the chamber  1372  that is opposite to the droplet generator  1376 . Moreover, it is possible for the structure passageway 1305p and the target material path Ptm to coincide with a direction of gravity so that the apparatus  1260  acts as a gravity-driven drain configured to pass or trap the target material from the targets  1377 , such target material traveling within the chamber  1372 . 
     For example, the rigid inner sleeve  335  can have a cross-sectional shape other than a circle; such as polygonal or oval. As another example, another inner guard can be arranged relative to the first flange  325  (in addition to the inner guard  1153  arranged relative to the second flange  330 ). As a further example, it is possible to arrange the apparatus  1260  at a wall of the chamber  1372  such that the first flange  325  of the apparatus  1260  is fixed directly to the chamber wall and the second flange  330  is fixed to a wall of a second chamber (which can be the receptacle  1210 ). 
     Other aspects of the invention are set out in the following numbered clauses. 
     1. An apparatus comprising: 
     a mechanically insulating device comprising a flexible bellows extending between first and second flanges, the flexible bellows defining a bellows passageway that extends along an axial direction between openings of the first and second flanges;   a rigid inner sleeve affixed to or supported by the first flange and extending along the bellows passageway in the axial direction, the rigid inner sleeve having an outer diameter that is less than an inner diameter of the flexible bellows; and   a shield device at least partly fixed to or supported by the second flange and defining an axial device opening having a diameter that is less than the inner diameter of the flexible bellows and is greater than the outer diameter of the rigid inner sleeve;   wherein the shield device is configured to enable relative motion between the first and second flanges, the relative motion including translational motion along one or more directions that are perpendicular to the axial direction and rotational motion about one or more directions that are perpendicular to the axial direction.   

     2. The apparatus of clause 1, wherein the shield device extends into the bellows passageway. 
     3. The apparatus of clause 1, wherein a distance between an inner diameter of the flexible bellows and the outer diameter of the rigid inner sleeve is greater than about 10%, greater than about 20%, or greater than about 30%, of the inner diameter of the flexible bellows. 
     4. The apparatus of clause 1, wherein the shield device comprises one or more disks that extend along a direction that is not parallel to the axial direction. 
     5. The apparatus of clause 4, wherein the direction in which the one or more disks extend is perpendicular to the axial direction. 
     6. The apparatus of clause 4, wherein the one or more disks comprise a plurality of disks, and an outer diameter of at least one disk is different from the outer diameter of each other disk, and an inner diameter of at least one disk is different from the inner diameter of each other disk. 
     7. The apparatus of clause 4, wherein the one or more disks comprise a plurality of disks, and an outer diameter of at least one disk is equal to the outer diameter of another disk, and an inner diameter of at least one disk is equal to the inner diameter of another disk. 
     8. The apparatus of clause 4, wherein each disk is constrained from moving along the axial direction and is free to move along a direction not parallel to the axial direction. 
     9. The apparatus of clause 4, wherein each disk is defined by a thickness along the axial direction that allows each disk to be installed adjacent to the second flange. 
     10. The apparatus of clause 4, wherein each of the one or more disks comprises a slit that extends from an outer diameter of the disk to an inner diameter of the disk. 
     11. The apparatus of clause 4, wherein the shield device further comprises a disk housing configured to retain the one or more disks. 
     12. The apparatus of clause 11, wherein the disk housing is defined by an inner diameter that is equal to the inner diameter of the flexible bellows. 
     13. The apparatus of clause 11, wherein at least one disk of the one or more disks has an outer diameter that is greater than an inner diameter of the disk housing. 
     14. The apparatus of clause 11, wherein the one or more disks comprise a plurality of disks including a small disk that has an outer diameter that is less than a sum of an inner diameter of the disk housing plus an annular radius of the disk housing, the small disk sandwiched between two disks each having outer diameters that are greater than the sum of the inner diameter of the disk housing plus the annular radius of the disk housing. 
     15. The apparatus of clause 11, wherein each disk is defined by a thickness along the axial direction such that the one or more disks are receivable within the disk housing. 
     16. The apparatus of clause 1, wherein the shield device is configured to at least partially cover or cover a region between the flexible bellows and the rigid inner sleeve. 
     17. The apparatus of clause 16, wherein the particulates include one or more of solid particles, fluid particles, and splashes. 
     18. The apparatus of clause 1, wherein the flexible bellows comprises pleats configured to fold and unfold to enable the relative motion between the first and second flanges. 
     19. The apparatus of clause 1, wherein the shield device is made of a metal that includes a coating configured to prevent particulates from contaminating the shield device. 
     20. The apparatus of clause 19, wherein: 
     the particulates include one or more of solid particles, fluid particles, and splashes; and   the shield device coating is configured to: repel fluid particles to thereby prevent the fluid particles from accumulating on the shield device; and prevent solid particles solidified on the shield device from sticking to the shield device.   

     21. The apparatus of clause 20, wherein the shield device coating is further configured to prevent corrosion of an exterior surface of the shield device, such corrosion being caused by contamination by the particulates. 
     22. The apparatus of clause 19, wherein the metal is stainless steel and the shield device coating is a metal nitride or a metal oxide. 
     23. The apparatus of clause 1, wherein the rigid inner sleeve is made of a metal. 
     24. The apparatus of clause 23, wherein the metal has a high thermal conductivity. 
     25. The apparatus of clause 1, wherein the rigid inner sleeve is made of molybdenum, aluminum, copper, aluminum oxide, diamond, or graphite. 
     26. The apparatus of clause 23, wherein the rigid inner sleeve includes a coating configured to prevent particulates from contaminating one or more of the shield device and the rigid inner sleeve. 
     27. The apparatus of clause 26, wherein: the particulates include one or more of: solid particles, fluid particles, and splashes; and the rigid inner sleeve coating is configured to: repel the fluid particles to thereby prevent the fluid particles from accumulating on the shield device; and prevent solid particles solidified on the shield device from sticking to the shield device. 
     28. The apparatus of clause 27, wherein the rigid inner sleeve coating is configured to repel fluid particles along a direction that is parallel to the axial direction or away from the shield device such that when a fluid propagates through the rigid inner sleeve such fluid detaches from the rigid inner sleeve having a propagation direction that is parallel to the axial direction or away from the shield device. 
     29. The apparatus of clause 27, wherein the rigid inner sleeve coating is further configured to prevent corrosion of an exterior surface of the shield device, such corrosion caused by contamination of the particulates. 
     30. The apparatus of clause 1, wherein the rigid inner sleeve includes a coating of a metal nitride, a metal oxide, or a silicon nitride. 
     31. The apparatus of clause 1, further comprising a heating apparatus configured to adjust a temperature of the rigid inner sleeve. 
     32. The apparatus of clause 31, wherein the heating apparatus is in direct thermal communication with an outer surface of the rigid inner sleeve to adjust the temperature of the rigid inner sleeve by thermal conduction and the heating apparatus is not in direct thermal communication with the flexible bellows. 
     33. The apparatus of clause 1, wherein the first and second flanges are vacuum flanges. 
     34. The apparatus of clause 1, further comprising an inner guard extending over an opening of one or more of: the first flange and the second flange. 
     35. The apparatus of clause 34, wherein the inner guard is made of a metal that includes a guard coating configured to prevent particulates from contaminating the inner guard. 
     36. The apparatus of clause 35, wherein the distance between the inner guard and the respective flange is small enough to reduce an amount of particulates from contaminating the respective flange. 
     37. The apparatus of clause 36, wherein the distance between the inner guard and the respective flange is configured to reduce the amount of particulates from contaminating the respective flange at least in part because particles are repelled from the surfaces of the inner guard and the respective flange. 
     38. The apparatus of clause 36, wherein the particulates include solid particles and fluid particles, and the coating is configured to: repel the fluid particles to prevent the fluid particles from accumulating on the inner guard; and prevent the solid particles from sticking to the inner guard. 
     39. The apparatus of clause 35, wherein the guard coating is a metal nitride. 
     40. The apparatus of clause 1, wherein the rigid inner sleeve and the shield device are arranged so that the rigid inner sleeve is configured to penetrate the opening of the shield device. 
     41. The apparatus of clause 1, wherein the flexible bellows is coupled or fixed at a first end to the first flange and at a second end to the second flange. 
     42. The apparatus of clause 1, wherein the rigid inner sleeve is either affixed directly to the first flange or is affixed to a first end of the flexible bellows that is fixed to the first flange. 
     43. An extreme ultraviolet (EUV) light source comprising:
     a chamber comprising a chamber wall defining a fluid portal; and   an apparatus retained at the chamber wall, the apparatus comprising:   a mechanically insulating device comprising a flexible bellows extending between first and second flanges, the flexible bellows defining a bellows passageway that extends along an axial direction between openings of the first and second flanges that are in fluid communication with the fluid portal;   a rigid inner sleeve being affixed to or supported by the first flange and extending along the bellows passageway in the axial direction, the rigid inner sleeve having an outer diameter that is less than an inner diameter of the flexible bellows; and   a shield device at least partly fixed to or supported by the second flange and defining an axial device opening having a diameter that is less than the inner diameter of the flexible bellows and is greater than the outer diameter of the rigid inner sleeve;   wherein the shield device is configured to enable relative motion between the first and second flanges caused by movement of the chamber wall, the relative motion including translational motion along one or more directions that are perpendicular to the axial direction and rotational motion about one or more directions that are perpendicular to the axial direction.   

     44. The EUV light source of clause 43, wherein the first flange is fixed to the chamber wall and the second flange is fixed to a second wall of a second chamber. 
     45. The EUV light source of clause 43, further comprising a target material supply system comprising a droplet generator configured to produce a stream of targets, wherein the targets comprise a target material that emits EUV light when in a plasma state. 
     46. The EUV light source of clause 45, further comprising a structure comprising a structure passageway configured to receive target material that travels along a target material path, wherein the first flange is fixed to a wall of the structure. 
     47. The EUV light source of clause 46, wherein the second flange is fixed to a wall of a receptacle configured to receive target material from the structure passageway. 
     48. The EUV light source of clause 47, wherein the first and second flanges are vacuum flanges, the first flange is fixed to the wall of the structure with a vacuum seal, and the second flange is fixed to the wall of the receptacle with another vacuum seal. 
     49. The EUV light source of clause 48, further comprising a first inner guard extending over the opening of the first flange, and a second inner guard extending over the opening of the second flange, wherein each of the first and second inner guards is configured to: block the target material from contacting the respective vacuum seal; and prevent the target material from solidifying between the respective flange and the structure wall at the location of the vacuum seal and forming an unwanted joint between the respective flange and the structure wall. 
     50. The EUV light source of clause 46, wherein the structure is arranged at a location of the chamber opposite to the droplet generator. 
     51. The EUV light source of clause 46, wherein the structure passageway coincides with a direction of gravity and a flow direction of the target material at least partly coincides with the direction of gravity. 
     52. The EUV light source of clause 44, wherein the apparatus is implemented as a gravity-driven drain configured to pass or trap target material traveling within the chamber. 
     53. An apparatus comprising: 
     a mechanically insulating device comprising a flexible bellows extending between first and second flanges, the flexible bellows defining a bellows passageway that extends along an axial direction between openings of the first and second flanges;   a rigid inner sleeve being affixed to or supported by the first flange and extending along the bellows passageway in the axial direction, the rigid inner sleeve having an outer diameter that is less than an inner diameter of the flexible bellows; and   a shield device at least partly fixed to or supported by the second flange and defining an axial device opening having a diameter that is less than the inner diameter of the flexible bellows and is greater than the outer diameter of the rigid inner sleeve, wherein the shield device is configured to at least partly cover or cover a region between the flexible bellows and the rigid inner sleeve.   

     54. The apparatus of clause 53, wherein the shield device comprises one or more movable disks supported by a disk housing fixed to the second flange, each disk defining an opening large enough to accommodate the rigid inner sleeve, wherein each disk has an inner diameter that is less than the inner diameter of the flexible bellows. 
     55. The apparatus of clause 54, wherein the one or more movable disks are configured to enable relative motion between the first and second flanges, the relative motion including translational motion along one or more directions that are perpendicular to the axial direction and rotational motion about one or more directions that are perpendicular to the axial direction. 
     56. An apparatus comprising: 
     a structure comprising a structure interior configured to receive target material that travels along a path;   a receptacle including a volume; and   a connection device between the structure and the receptacle, and configured to provide fluid communication between the structure interior and the receptacle volume, the connection device comprising:   a mechanically insulating device comprising a flexible bellows extending between first and second flanges, the flexible bellows defining a bellows passageway that extends along an axial direction between openings of the first and second flanges, the first flange fixed to a wall of the structure and the second flange fixed to the receptacle;   an inner sleeve affixed to or supported by the first flange and extending within the bellows passageway in the axial direction, the inner sleeve having an outer diameter that is less than an inner diameter of the flexible bellows and defining a sleeve passageway within the bellows passageway, such that the sleeve passageway provides the fluid communication between the structure interior and the receptacle volume; and   a shield device at least partly fixed to or supported by the second flange and defining an axial device opening having a diameter that is less than the inner diameter of the flexible bellows and is greater than the outer diameter of the inner sleeve.   

     57. The apparatus of clause 56, wherein the receptacle is in fluid communication with a nozzle system of a target supply system configured to supply target material to an EUV light source. 
     58. The apparatus of clause 56, wherein the receptacle is a part of a target material debris collection and drain system of a drain module within a chamber of an EUV light source. 
     Other implementations are within the scope of the following claims.