Tin handling device and apparatus, EUV generation apparatus, EUV utilization apparatus, use thereof, and method of removing tin

Abstract

A receiving container of a tin handling device is configured to receive tin removed from a collection container. A transfer line is configured to transfer tin from the collection container to the receiving container. The tin handling device is configured to transfer tin from the collection container to the receiving container via the transfer line by way of one or both of: a pressure differential and a siphon. There is also provided a tin handling apparatus with such a tin handling device and a collection container configured to collect tin. Also described are an EUV generation apparatus, an EUV utilization apparatus, a method of removing tin from a collection container, as well as the use of such a device, apparatus or method in an EUV utilization method or apparatus.

Description

TIN HANDLING DEVICE AND APPARATUS. EUV GENERATION APPARATUS. EUV UTILIZATION APPARATUS. USE THEREOF. AND METHOD OF REMOVING TINCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority of US application 63 / 602,423 which was filed on 23 November 2023 and US application 63 / 704,243 which was filed on 07 October 2024 which is incorporated herein in its entirety by reference.FIELD

[0002] The present disclosure relates to a tin handling device, a tin handling apparatus, an EUV generation apparatus, an EUV utilization apparatus, a method of removing tin from a collection container, as well as the use of such a tin handling device, tin handling apparatus, EUV generation apparatus, EUV utilization apparatus, or method in an EUV utilization method or apparatus. The present disclosure has particular, but not exclusive, application in an EUV lithographic apparatus and method, and EUV inspection apparatus and method.BACKGROUND

[0003] A lithographic apparatus is a machine constructed to apply a desired pattern onto a substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithographic apparatus may for example project a pattern from a patterning device (e.g. a mask) onto a layer of radiation-sensitive material (resist) provided on a substrate. A lithographic apparatus is an example of an EUV utilization apparatus. Another example of an EUV utilization apparatus is an EUV inspection apparatus.

[0004] The wavelength of radiation used by a lithographic apparatus to project a pattern onto a substrate determines the minimum size of features which can be formed on that substrate. A lithographic apparatus which uses EUV radiation, being electromagnetic radiation having a wavelength within the range 4-20 nm, may be used to form smaller features on a substrate than a conventional lithographic apparatus (which may for example use electromagnetic radiation with a wavelength of 193 nm).

[0005] In an EUV utilization apparatus, a laser, which may, for example, be a CO2 laser, is arranged to deposit energy via a laser beam into a fuel, such as tin (Sn) which is provided from a fuel emitter. Although tin is referred to in the following description, any suitable fuel may be used. The fuel may, for example, be in liquid form, and may, for example, be a metal or alloy. The fuel emitter may comprise a nozzle configured to direct tin, e.g. in the form of droplets, along a trajectory towards a plasma formation region. The laser beam is incident upon the tin at the plasma formation region. The deposition of laser energy into the tin creates a plasma at the plasma formation region. Radiation,including EUV radiation, is emitted from the plasma during de-excitation and recombination of ions of the plasma.

[0006] Since the fuel, such as tin, is turned into a plasma to generate EUV radiation, which then reforms to reform the fuel, the fuel is not used up in the same way as, for example, hydrocarbon fuel is used up in an internal combustion engine and then exhausted to the atmosphere. As such, the fuel used to generate EUV radiation is collected. In addition, not all of the droplets of the fuel which are provided are irradiated and converted into plasma, so some droplets of the fuel are caught by a fuel catching apparatus and then stored in a reservoir.

[0007] Over time, the reservoir used to store the fuel which has been used in the EUV utilization apparatus needs to be emptied. Presently, this is done by removing the reservoir from the EUV utilization apparatus, transporting it to a different location where it is put into an oven upside down and the heat of the oven melts the fuel to allow it to drain away. This is time consuming, causing significant downtime for the EUV utilization apparatus, and risks damage and contamination to the reservoir. Whilst it is possible to reduce downtime by providing spare reservoirs, this still does not address the time taken and risk associated with removing one reservoir and replacing it with another, and it is still necessary to drain any spare reservoirs.

[0008] The present disclosure has been provided in an attempt to address at least some of the problems identified above.SUMMARY OF THE INVENTION

[0009] According to a first aspect of the present disclosure, there is provided a tin handling device configured to remove tin from a collection container, the device comprising a receiving container configured to receive tin removed from the collection container; a transfer line configured to transfer tin from the collection container to the receiving container; wherein the tin handling device is configured to transfer tin from the collection container to the receiving container via the transfer line by way of one or both of: a pressure differential and a siphon.

[0010] The device according to the present disclosure allows for tin to be removed from a collection container, which is a container that slowly fills up with tin when an associated EUV utilization apparatus is in use, and transferred to a separate receiving container without the need to disconnect the collection container. This avoids the time, risk, and difficulty associated with physically removing the collection container from an associated EUV utilization apparatus. The collection container usually comprises one or more heaters which are sufficiently powerful to melt any tin within the container or to keep it in a molten state. As such, the liquid tin may be removed from the collection container and transferred to the receiving container via the transfer line . This may be achieved by one of or a combination of a pressure differential and a siphon. A pressure differential can either be an overpressure or an under pressure. For example, the pressure in the receiving container may be decreased to less than that of the collection container such that there is a tendency of the liquid tin topass from the collection container to the receiving container. Similarly, the pressure within the collection container may be increased relative to the receiving container to generate the pressure differential. A siphon may alternatively or additionally be used to transfer the liquid tin. A siphon allows for the passive flow of a liquid from one container to another and, once the flow has begun, no additional external energy input is required. As such, a pressure differential could be used to begin the flow of liquid tin and then released to allow the tin to continue to flow via a siphon effect. This reduce the wear on any pump used to generate a pressure differential and also reduces power requirements.

[0011] The tin handling device may comprise a vacuum pump configured to reduce a pressure within the receiving container. A vacuum pump is operable to reduce the pressure within the receiving container such that when the transfer line is in fluid communication with a collection container containing liquid tin at ambient pressure, there is a pressure differential which causes the liquid tin to flow through the transfer line.

[0012] The receiving container may be positionable at a height lower than the collection container when in use to allow the siphon to transfer tin from the collection container to the receiving container. A siphon does not rely on a pressure differential to cause flow of a liquid, but rather the energy needed to cause flow is provided by the potential energy of the liquid being transferred. This means that once the flow has begun, no further external energy is required to maintain the flow of liquid and it will naturally cease once the level of the liquid tin in the collection container is lower than an inlet to the transfer line.

[0013] The receiving container may comprise a pump including a plurality of heating elements that is configured to pump tin via selective melting and freezing of the tin. Such pumps are described in EP3974905 and EP21769432, the contents of which is incorporated herein by reference. When tin melts, the volume of the tin increases and if the liquid tin is enclosed when it melts, the pressure will increase. By controlling the melting and solidification of tin, it is possible to generate a pumping force. In more detail, a pump is provided with a reservoir in thermal communication with an array of heating elements. The tin from the collection container is in fluid communication with the pump reservoir. The heating elements are operated to allow a first portion of the tin to solidify thereby forming a plug. The heating elements are operated to allow an upstream second portion of the tin adjacent to the plug to solidify. The heating elements are then operated to melt a downstream portion of the plug to generate a portion of the tin at increased pressure.

[0014] The collection container may comprise a pressure chamber configured to contain a pressure below ambient pressure. The collection container may comprise a vessel within the pressure chamber that is configured to receive tin removed from the collection container. The vessel may be a drafted vessel. A drafted vessel is one in which the sides are not parallel to one another. The vessel may be separable from the pressure chamber. In this way, the pressure within the pressure vessel can be reduced in order to cause the liquid tin to flow into the vessel. Once the tin has been passed into the vessel, the vessel can be removed and the tin removed.

[0015] A valve may be provided between the receiving container and the transfer line. The valve may be closed when the receiving container is being pumped down to reduce the pressure therein and can then be opened to begin the flow of liquid tin. The valve can be closed in order to stop the flow of liquid tin. In this way the valve may be configured to regulate pressure within the receiving container.

[0016] The transfer line may be a heated transfer line. Since liquid tin is being transferred, it is possible that the tin may cool sufficiently to solidify if the transfer line is not appropriately insulated, is too long, or if the flow of liquid tin is too low. The provision of a heated transfer line prevents the possibility of the tin inadvertently solidifying within the transfer line. The transfer line may comprise one or more heaters. The transfer line may comprise an array of heaters. The heaters may be configured to heat the tin within the transfer line such that a radially outer portion of tin within the transfer line is melted. If a radially outer portion of tin within the transfer line is solid and a radially inner portion is liquid, this can result in a high pressure within the transfer line and potentially cause damage.

[0017] The device may comprise a controller that is configured to control the operation of the tin handling device. The controller may control one of more of: the pressure within the device, the pump which generates a pressure differential, the heated transfer line, the activation of any valves, and any heating elements. The controller may be configured to ensure safe operation. Safe operation is operation within predetermined parameters.

[0018] The receiving container may comprise one or more heaters configured to heat any tin therein to melt the tin or keep the tin in a liquid state. So that the tin does not pile up, it is desirable to keep in molten or to melt it so that it reaches an even level. In addition, when the receiving container is being emptied of tin, it is easier if the tin is liquid. The receiving container may contain a removable vessel that can be taken out of or disconnected from the rest of the receiving container. The tin within the removable vessel may have been allowed to solidify before the removable vessel is taken away in order to prevent the risk of spillage.

[0019] According to a second aspect of the present disclosure, there is provided a tin handling apparatus comprising a tin handling device according to the first aspect of the present disclosure, and a collection chamber configured to collect tin.

[0020] The collection container may be an existing component of an EUV generation or utilization device. The collection container may be mounted on an EUV generation or utilization device.

[0021] The collection container may be configured to receive an external supply of a gas. The gas may be nitrogen, but any other gas which is available may be used. Preferably, the gas does not contain oxygen in order to avoid oxidation of the tin. The collection container may be configured to be pressurised to remove tin from the collection container. The gas may be pressurised to push the liquid tin out of the collection container. In addition, the gas may serve to displace oxygen to prevent tin oxidation.

[0022] The collection container may comprise one or more heaters. The tin which enters the collection container may be molten, but will rapidly cool due to its small size. As such, without heating,the tin would form a mound within the collection container. The heaters may therefore be operable, whether continuously or intermittently, to melt the tin and thereby prevent mounding of the tin and make best use of the volume of the container to store the tin.

[0023] The collection container may further comprise one or more dedicated ports through which tin can be removed. The ports may have an adapter configured to connect to the transfer line. The adapter may be in fluid communication with a dip tube inside the container that is configured to allow liquid tin to be removed from the container.

[0024] According to a third aspect of the present disclosure, there is provided an EUV generation apparatus including a tin handling device or tin handling apparatus according to the first or second aspects of the present disclosure.

[0025] According to a fourth aspect of the present disclosure, there is provided an EUV utilization apparatus comprising a tin handling device, tin handling apparatus, or EUV generation apparatus according to the first, second, or third aspects of the present disclosure.

[0026] The EUV utilization apparatus may be a lithographic apparatus or an EUV inspection apparatus.

[0027] According to a fifth aspect of the present disclosure, there is provided a method of removing tin from a collection container, the method including: fluidly connecting a transfer line between a collection container holding liquid tin and a receiving container configured to receive the liquid tin, and transferring the liquid tin from the collection container to the receiving container via the transfer line by way of one or both of a pressure differential and a siphon.

[0028] As mentioned in respect of the previous aspects of the present disclosure, the ability to remove liquid tin from a collection container without having to remove the container from the apparatus to which it is connected in nominal use has a number of advantages, including reducing the downtime of the apparatus to which it is connected, avoiding the need to have spare containers that can be used whilst a container is being emptied, avoid the risk of contamination, and avoiding the need to have a separate facility for heating the container to remove accumulated tin.

[0029] The method may comprise operating the pump to create a pressure differential such that liquid tin passes through the transfer line.

[0030] The method may comprise providing a pressurising gas to the collection container to push liquid tine to the receiving container via the transfer line. The pressurising gas may be nitrogen. The method may comprise both pressurizing the collection container and reducing the pressure in the receiving container in order to make the liquid tin flow between the two containers.

[0031] The method may comprise providing tin within the transfer line. The method may further comprise fluidly connecting an end of the transfer line to the liquid tin within the collection container, fluidly connecting another end of the transfer line to a receiving container, the end connected to the receiving container being at a lower height than the end connected to the collection container, and melting the tin within the transfer line to siphon the liquid tin from the collecting container to thereceiving container via the transfer line. In order for a siphon to function, the tube through which the liquid flows must contain the liquid. Where the tube instead contains a gas, usually the gas will be removed from the tube and the pressure differential will pull liquid through the tube to begin the siphon. By pre-charging the transfer line with tin and then melting the tin, it is possible to start the siphon without the need for a pressure differential. This means that no pump or pressure vessel is required. The transfer line may be allowed to cool and any tin therein to solidify in order to pre-charge the transfer line for next use.

[0032] The method may comprise selectively melting and freezing the tin in order to pump the tin from the collection container to the receiving container.

[0033] According to a sixth aspect of the present disclosure, there is provided the use of the tin handling device, the tin handling apparatus, EUV generation apparatus, EUV utilization apparatus, or method according to the first to fifth aspects of the present disclosure in an EUV utilization method or apparatus.

[0034] It will be appreciated that features described in respect of one embodiment may be combined with any features described in respect of another embodiment and all such combinations are expressly considered and disclosed herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0036] Figure 1 schematically depicts a lithographic apparatus;

[0037] Figure 2 schematically depicts a tin handling device; and

[0038] Figure 3 schematically depicts a tin handling apparatus.

[0039] The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and / or structurally similar elements.DETAILED DESCRIPTION

[0040] Figure 1 shows a lithographic system including a gas-based laser. The lithographic system comprises a radiation source SO and a lithographic apparatus LA. The radiation source SO is configured to generate an extreme ultraviolet (EUV) radiation beam B. The lithographic apparatus LA comprises an illumination system IL, a support structure MT configured to support a patterning device MA (e.g. a mask), a projection system PS and a substrate table WT configured to support a substrate W. The illumination system IL is configured to condition the radiation beam B before it is incident upon the patterning device MA. The projection system is configured to project the radiation beam B(now paterned by the mask MA) onto the substrate W. The substrate W may include previously formed paterns. Where this is the case, the lithographic apparatus aligns the paterned radiation beam B with a patern previously formed on the substrate W. In this example, a pellicle 15 is depicted in the path of the radiation and protecting the paterning device MA. It will be appreciated that the pellicle 15 may be located in any required position and may be used to protect any of the mirrors in the lithographic apparatus. The pellicle 15 is optional, and may be absent.

[0041] The radiation source SO, illumination system IL, and projection system PS may all be constructed and arranged such that they can be isolated from the external environment. A gas at a pressure below atmospheric pressure (e.g. hydrogen) may be provided in the radiation source SO. A vacuum may be provided in illumination system IL and / or the projection system PS. A small amount of gas (e.g. hydrogen) at a pressure well below atmospheric pressure may be provided in the illumination system IL and / or the projection system PS.

[0042] The radiation source SO shown in Figure 1 is of a type which may be referred to as a laser produced plasma (LPP) source. A laser 1, which may for example be a CO2 laser, is arranged to deposit energy via a laser beam 2 into a fuel, such as tin (Sn) which is provided from a fuel emiter 3. Although tin is referred to in the following description, any suitable fuel may be used. The fuel may for example be in liquid form, and may for example be a metal or alloy. The fuel emiter 3 may comprise a nozzle configured to direct tin, e.g. in the form of droplets, along a trajectory towards a plasma formation region 4. The laser beam 2 is incident upon the tin at the plasma formation region 4. The deposition of laser energy into the tin creates a plasma 7 at the plasma formation region 4. Radiation, including EUV radiation, is emited from the plasma during de-excitation and recombination of ions of the plasma. A tin catch apparatus 26 may be provided generally opposite to the fuel emiter 3 and is configured to catch droplets of tin which pass through the plasma formation region 4. The tin catch apparatus 26 is schematically depicted as spanning enclosing structure 9, but it will be appreciated that this does not necessarily require that the tin catch apparatus be contained within the enclosing structure 9. The tin catch apparatus 26 comprises a collection container 23 into which tin is collected.

[0043] The EUV radiation is collected and focused by a near normal incidence radiation collector 5 (sometimes referred to more generally as a normal incidence radiation collector). The collector 5 may have a multilayer structure which is arranged to reflect EUV radiation (e.g. EUV radiation having a desired wavelength such as 13.5 nm). The collector 5 may have an elliptical configuration, having two ellipse focal points. A first focal point may be at the plasma formation region 4, and a second focal point may be at an intermediate focus 6, as discussed below.

[0044] The laser 1 may be separated from the radiation source SO. Where this is the case, the laser beam 2 may be passed from the laser 1 to the radiation source SO with the aid of a beam delivery system (not shown) comprising, for example, suitable directing mirrors and / or a beam expander, and / or other optics. The laser 1 and the radiation source SO may together be considered to be a radiation system.

[0045] Radiation that is reflected by the collector 5 forms a radiation beam B. The radiation beam B is focused at a point 6 to form an image of the plasma formation region 4, which acts as a virtual radiation source for the illumination system IL. The point 6 at which the radiation beam B is focused may be referred to as the intermediate focus. The radiation source SO is arranged such that the intermediate focus 6 is located at or near to an opening 8 in an enclosing structure 9 of the radiation source.

[0046] The radiation beam B passes from the radiation source SO into the illumination system IL, which is configured to condition the radiation beam. The illumination system IL may comprise a facetted field mirror device 10 and a facetted pupil mirror device 11. The faceted field mirror device 10 and faceted pupil mirror device 11 together provide the radiation beam B with a desired cross- sectional shape and a desired angular distribution. The radiation beam B passes from the illumination system IL and is incident upon the patterning device MA held by the support structure MT. The patterning device MA reflects and patterns the radiation beam B. The illumination system IL may comprise other mirrors or devices in addition to or instead of the faceted field mirror device 10 and faceted pupil mirror device 11.

[0047] Following reflection from the patterning device MA the patterned radiation beam B enters the projection system PS. The projection system comprises a plurality of mirrors 13, 14 which are configured to project the radiation beam B onto a substrate W held by the substrate table WT. The projection system PS may apply a reduction factor to the radiation beam, forming an image with features that are smaller than corresponding features on the patterning device MA. A reduction factor of 4 may for example be applied. Although the projection system PS has two mirrors 13, 14 in Figure 1, the projection system may comprise any number of mirrors (e.g. six mirrors).

[0048] The radiation sources SO shown in Figure 1 may comprise components which are not illustrated. For example, a spectral filter may be provided in the radiation source. The spectral filter may be substantially transmissive for EUV radiation but substantially blocking for other wavelengths of radiation such as infrared radiation.

[0049] Figure 2 is a schematic depiction of a tin handling device 16 according to the present disclosure. The tin handling device 16 comprises a receiving container 17 that is configured to receive and store liquid tin which has been extracted from another container. The tin handling device 16 comprises a pressure vessel 18 and a vessel 19 that receives and stores liquid tin. The pressure vessel 18 is shown as surrounding the vessel 19, but it will be appreciated that the pressure vessel 18 may engage with an upper portion of the vessel 19 to provide a volume which can be pumped down using vacuum pump 20, which is in fluid communication with the receiving container 17. A transfer line 21, which may be a heated transfer line, is in fluid communication with the receiving container 17 and another container (not shown) which contains liquid tin that needs to be removed. The transfer line may comprise a valve 22 to control the flow of liquid tin through the transfer line 21. It will be appreciated that the transfer line 21 is shown in schematic and may extend further than shown and does not have to,and preferably does not comprise angled turns. The valve 22 may be closed when the receiving container 17 is being pumped down to reduce the pressure within the receiving container 17. The valve22 may be opened to allow any liquid tin within the transfer line 21 to flow into the vessel 19. The receiving container 17 may comprise one or more heaters (not shown) that are able to melt any tin therein or to maintain any liquid tin therein in the molten state.

[0050] Figure 3 depicts a tin handling device 16 in fluid communication with a collection container23 to form a tin handling apparatus 24. The transfer line 21 is in fluid communication with any liquid tin held in the collection container 23. This may be via a dip tube to which the transfer line 21 is connected or the transfer line 21 may be configured to be submerged in liquid tin itself. As shown in Figure 3, the receiving container 17 may be at a lower height than the collection container 23 such that it is possible to siphon liquid tin from the collection container 23 to the receiving container 17 via transfer line 21. The height difference can be routinely selected such that a desired amount of liquid tin is transferred between the containers. A pressurising gas inlet 25 is provided and is configured to provide a gas to pressurise the collection container 23 to force liquid tin from the collection container 23 to the receiving container 17.

[0051] In use, liquid tin is present within the collection container 23. When it is desired to remove the liquid tin from the collection container 23, the tin handling device is fluidly engaged with the collection container 23 such that there is a pathway for the liquid tin to be transferred from the collection container 23 to the receiving container 17 via transfer line 21. The transfer of the liquid tin may be effected by a pressure differential, a siphon effect, or a combination of the two. Where the tin is transferred by way of a pressure differential, this may be achieved by providing gas via the pressurising gas inlet 25 such that the pressure within the collection container 23 is greater than the pressure within the receiving container 17. Alternatively or additionally, the vacuum pump 20 may be activated to reduce the pressure within the receiving container 17 to similarly cause the liquid tin to transfer from the collection container 23 to the receiving container 17. Once the tin has started flowing, it is possible to continue the flow using a siphon effect, which requires that the receiving container 17 be at a lower height than the collection container 23. The liquid tin will flow via the siphon until the level of the tin falls below the inlet to the transfer line 21 or until the level of the liquid tin in the collection and receiving containers is equalised.

[0052] Any metal surface of the components described above which can come into contact with liquid tin may be coated with a non-corrosive material. One example of such material is TiN which can be applied as a coating. By such coating, corrosion of the respective metals may be reduced or prevented, whereby preserving purity level of the removed tin.

[0053] CLAUSES1. A tin handling device configured to remove tin from a collection container, the device comprising:- a receiving container configured to receive tin removed from the collection container;- a transfer line configured to transfer tin from the collection container to the receiving container;wherein the tin handling device is configured to transfer tin from the collection container to the receiving container via the transfer line by way of one or both of: a pressure differential and a siphon.2. The tin handling device of clause 1, further comprising a vacuum pump configured to reduce a pressure within the receiving container.3. The tin handling device of any preceding clause, wherein the receiving container is positionable at a height lower than the collection container when in use to allow the siphon to transfer tin from the collection container to the receiving container.4. The tin handling device of any preceding clause, wherein the receiving container comprises a pump including a plurality of heating elements that is configured to pump tin via selective melting and freezing of the tin.5. The tin handling device of any preceding clause, wherein the collection container comprises a pressure chamber configured to contain a pressure below ambient pressure.6. The tin handling device of clause 5 wherein the collection container further comprises a vessel within the pressure chamber that is configured to receive tin removed from the collection container.7. The tin handling device of any preceding clause, wherein a valve is provided between the receiving container and the transfer line.8. The tin handling device of clause 7, wherein the valve is configured to regulate pressure within the receiving container.9. The tin handling device of any of any preceding clause, wherein the transfer line is a heated transfer line.10. The tin handling device of any preceding clause, further comprising a controller that is configured to control the operation of the tin handling device.11. The tin handling device of any preceding clause, wherein the receiving container comprises one or more heaters configured to heat any tin therein to melt the tin or keep the tin in a liquid state.12. The tin handling device of any preceding clause, wherein an internal surface area of one or more of the collector container, the receiving container, the transfer line is configured to be exposed to contact with tin, wherein the internal surface area is provided with a non-corrosive coating layer.13. The tin handling device of claim 12, wherein the non-corrosive coating layer comprises TiN.14. A tin handling apparatus comprising a tin handling device according to one or more of the preceding clauses, and a collection container configured to collect tin.15. The tin handling apparatus of clause 14, wherein the collection container is configured to receive an external supply of a gas, optionally wherein the gas is nitrogen, optionally wherein the gas is oxygen- free, and optionally wherein the collection container is configured to be pressurised to remove tin from the collection container.16. The tin handling apparatus of any of clauses 14 and 15, wherein the collection container comprises one or more heaters.17. The tin handling apparatus of any of clauses 14 to 16, wherein the collection container further comprises one or more dedicated ports through which tin can be removed.18. An EUV generation apparatus including a tin handling device or tin handling apparatus according to any preceding clause.19. An EUV utilization apparatus comprising a tin handling device, a tin handling apparatus, or EUV generation apparatus according to any preceding clause.20. An EUV utilization apparatus according to clause 19, wherein the EUV utilization apparatus is a lithographic apparatus or an EUV inspection apparatus.21. A method of removing tin from a collection container, the method including:- fluidly connecting a transfer line between a collection container holding liquid tin and a receiving container configured to receive the liquid tin, and- transferring the liquid tin from the collection container to the receiving container via the transfer line by way of one or both of a pressure differential and a siphon.22. The method according to clause 21, wherein the method comprises operating a pump to create a pressure differential such that liquid tin passes through the transfer line.23. The method according to clause 21 or 22, wherein the method comprises providing a pressurising gas to the collection container to push liquid tin to the receiving container via the transfer line, optionally wherein the pressurising gas is nitrogen.24. The method according to any of clauses 21 to 23, wherein the method comprises providing tin within the transfer line, fluidly connecting an end of the transfer line to the liquid tin within the collection container, fluidly connecting another end of the transfer line to a receiving container, the end connected to the receiving container being at a lower height than the end connected to the collection container and melting the tin within the transfer line to siphon the liquid tin from the collecting container to the receiving container via the transfer line.25. The method according to any of clauses 21 to 24, wherein the method further comprises selectively melting and freezing the tin in order to pump the tin from the collection container to the receiving container.26. The use of the tin handling device, tin handling apparatus, EUV generation apparatus, EUV utilization apparatus according to any of clauses 1 to 20 or method according to any of clauses 21 to 25 in an EUV utilization method or apparatus.

[0054] It will be appreciated that the various aspects described herein may be provided individually or in combination.

[0055] While specific options have been described above, it will be appreciated that the invention may be practiced otherwise than as described.

[0056] The descriptions above are intended to be illustrative, not limiting. Thus it will be apparent to one skilled in the art that modifications may be made to the concepts as described without departing from the scope of the claims set out below.

[0057] In summary, the present disclosure provides means and methods for removing liquid tin from a collection container without the need to detach the collection container from the apparatus to which it is attached or forms part of. This avoids the risk of contamination, reduces downtime, and avoids the need to have spare collection containers. The use of a separate device for removing the liquid tin means that the device does not have to form part of the apparatus which is being drained of tin, which have strict space requirements and also means that a single device can be used to drain multiple different collection containers.

Claims

CLAIMS1. A tin handling device configured to remove tin from a collection container, the device comprising: a receiving container and a transfer line configured to transfer tin from the collection container to the receiving container; wherein the tin handling device is configured to transfer tin from the collection container to the receiving container via the transfer line by way of one or both of: a pressure differential and a siphon.

2. The tin handling device of claim 1, further comprising a vacuum pump configured to reduce a pressure within the receiving container.

3. The tin handling device of any of the preceding claims, wherein the receiving container comprises a pump including a plurality of heating elements that is configured to pump tin via selective melting and freezing of the tin.

4. The tin handling device of any of the preceding claims, wherein a valve is provided between the receiving container and the transfer line, wherein the valve is configured to regulate a pressure within the receiving container.

5. The tin handling device of any of the preceding claims, wherein the transfer line is a heated transfer line.

6. The tin handling device of any of the preceding claims, wherein the receiving container comprises one or more heaters configured to heat any tin therein to melt the tin or keep the tin in a liquid state.

7. A tin handling apparatus comprising the tin handling device according to any of claims 1 to 6 and a collection container configured to collect tin.

8. The tin handling apparatus of claim 7, wherein the receiving container is positioned at a height lower than the collection container to allow the siphon to transfer tin from the collection container to the receiving container.

9. The tin handling apparatus of claim 7 or 8, wherein the collection container comprises a pressure chamber configured to contain a pressure below ambient pressure.

10. The tin handling apparatus of claim 9, wherein the collection container further comprises a vessel within the pressure chamber that is configured to receive tin removed from the collection container.

11. The tin handling apparatus of any of claims 7 to 10, wherein the collection container is configured to receive an external supply of a gas.

12. The tin handling apparatus of any of claims 7 to 11, wherein the collection container comprises one or more heaters.

13. The tin handling apparatus of any of claims 7 to 12, wherein the collection container further comprises one or more dedicated ports through which tin can be removed.

14. An EUV generation apparatus including the tin handling device of any of claims 1 to 6 or the tin handling apparatus of any of claims 7 to 13.

15. An EUV utilization apparatus comprising the tin handling device of any of claims 1 to 6, the tin handling apparatus of any of claims 7 to 13, and / or the EUV generation apparatus of claim 14.

16. A method of removing tin from a collection container, the method comprising: fluidly connecting a transfer line between a collection container holding liquid tin and a receiving container configured to receive the liquid tin, and transferring the liquid tin from the collection container to the receiving container via the transfer line by way of one or both of a pressure differential and a siphon.

17. The method according to claim 16, wherein the method further comprises operating a pump to create a pressure differential such that liquid tin passes through the transfer line.

18. The method according to claim 16 or 17, wherein the method further comprises providing a pressurising gas to the collection container to push liquid tin to the receiving container via the transfer line.

19. The method according to any of claims 16 to 18, wherein the method further comprises providing tin within the transfer line, fluidly connecting an end of the transfer line to the liquid tin within the collection container, fluidly connecting another end of the transfer line to a receiving container, the end connected to the receiving container being at a lower height than the end connected to the collection container and melting the tin within the transfer line to siphon the liquid tin from the collecting container to the receiving container via the transfer line.

20. The method according to any of claims 16 to 19, wherein the method further comprises selectively melting and freezing the tin in order to pump the tin from the collection container to the receiving container.

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