JP2021516774A - Devices and methods for controlling debris in EUV light sources - Google Patents

Abstract

An EUV system is disclosed that includes measures for accumulating target material debris in the form of a liquid. The target material is prevented from splashing on the optics. The target material can be solidified and then brought to a location where it can be melted so that it can be discharged without contaminating the collector. [Selection diagram] FIG. 4B

Description

(Cross-reference of related applications)
[00001] This application claims the priority of US application Nos. 62 / 648,505 filed on March 27, 2018. This is incorporated herein by reference in its entirety.

[00002] The present disclosure relates to an apparatus and method for generating extreme ultraviolet (“EUV”) radiation from a plasma generated by the discharge or laser ablation of a target material in a container. In such applications, optics are used to collect and guide radiation for use in, for example, semiconductor photolithography and inspection.

[00003] Extreme ultraviolet radiation, such as electromagnetic radiation having a wavelength of about 50 nm or less (sometimes also referred to as soft x-rays), including radiation with a wavelength of about 13.5 nm, is used in the photolithography process. , Very small features can be generated on substrates such as silicon wafers.

[00004] Methods for generating EUV radiation include converting the target material into a plasma state. The target material preferably comprises at least one element having one or more emission lines in the EUV portion of the electromagnetic spectrum, such as xenon, lithium, or tin. The target material may be a solid, liquid, or gas. One such method, often referred to as laser produced plasma (“LPP”: laser produced plasma), is required by irradiating a target material with the required ray emitting elements with a laser beam. Plasma can be generated.

[00005] One LPP technique involves generating a stream of target material droplets and irradiating at least a portion of these droplets with one or more laser emission pulses. Such an LPP source generates EUV radiation by binding laser energy to a target material having at least one EUV emitting element to generate a highly ionized plasma with an electron temperature of tens of eV.

[00006] Due to this process, plasma is typically generated in a closed container, such as a vacuum chamber, and the resulting EUV radiation is monitored using various types of metrology equipment. The process used to generate the plasma usually produces unwanted by-products in the plasma chamber in addition to the generation of EUV radiation. This by-product can include out-of-band radiation, high energy ions, and debris such as atoms and / or clumps / microdroplets of residual target material.

[00007] Energy radiation is emitted from the plasma in all directions. In one common configuration, at least a portion of the radiation is collected and guided to an intermediate position, and in some configurations it is further focused, so it is referred to as a near normal incident mirror (“collector mirror” or simply “collector”). Often referred to) is positioned. The collected radiation can then be sent from an intermediate position to the optics set, reticle, detector, and finally to the silicon wafer.

[00008] It is generally believed that the EUV portion of the spectrum requires the use of reflective optics for the optical elements of the system, including collectors, illuminators, and projected light boxes. These reflective optics can be implemented as the normal incident optics as described above or as the gaze incident optics. At relevant wavelengths, it is advantageous to implement the collector as a multi-layer mirror (MLM). As the name implies, this MLM generally consists of layers of material (MLM stacks) that are alternately arranged on a substrate or substrate. Also, the system optics can be configured as coated optical elements even if they are not implemented as MLMs.

[00009] Optical elements, especially collectors, must be placed in the vessel with the plasma to collect and redirect EUV radiation. The environment in the chamber is detrimental to the optics, for example reducing the reflectance of the optics and limiting their useful life. Optical elements in the environment can be exposed to high energy ions or particles of the target material. Particles of the target material, which are essentially debris from the laser evaporation process, can contaminate the exposed surface of the optics. Also, the particles of the target material can cause physical damage and local heating to the MLM surface.

_{[00010] In some systems, H 2} gas with a pressure in the range of about 0.5 to about 3 mbar is used in the vacuum chamber as a buffer gas for debris reduction. In the absence of gas, vacuum pressure makes it difficult to adequately protect the collector from target material debris emitted from the irradiated area. Hydrogen is relatively transparent to EUV radiation with a wavelength of about 13.5 nm, so other candidates such as He, Ar, or other gases that show higher absorption at about 13.5 nm. More suitable than gas.

[00011] H ₂ gas is introduced into the vacuum chamber, to slow the high energy of the debris (ions, atoms and mass) of the target material caused by the plasma. Debris slows down due to collisions with gas molecules. _{For this purpose, the flow of H 2} gas used can be in the opposite direction of the debris orbit and away from the collector. This acts to reduce target material deposition, implant, and sputtering damage to the collector's optical coating.

[00012] Nonetheless, one of the most difficult challenges for sources such as those described is the management of residual target material. In the process of converting the target material into vapors and particles, the residual target material is placed on all unobstructed surfaces and in the gas discharge path that carries the residual target material. accumulate. For example, when this gas is pumped to a mechanical pump through the top of a vane present in the chamber, material deposits on all of the cold metal parts. If the target material is tin, this can result in yarn-like tin wool that can fall into the collector optics or clog the discharge path.

[00013] Continuing to use tin as an example of the target material, one technique for controlling tin diffusion is to capture tin from vapors or particles on a surface heated above the melting point of tin. Including. There, the tin melts (or remains in a molten state) and flows into the capture receptacle. However, liquid tin tends to eject or "spit" in the presence of hydrogen radicals as observed in the EUV chamber, and this ejected tin can hit the collector. .. This is a major cause of collector deterioration. Second, liquid tin usually does not flow as intended. Liquid tin may drip onto the collector, for example, from structures in the chamber such as scrubber blades and gutters provided to remove some or all of the tin vapor in the chamber. Also, the scrubber groove may overflow and liquid tin may travel behind the blades to create a thermal short (ie, an unintended heat transfer path) and clog the flow path to the capture receptacle. In addition, liquid tin is highly corrosive, causing, for example, failure of the electric heater used to keep the collecting surface above the tin melting point. Also, due to the flow restriction caused by tin accumulation, the gas path in the vanes and collector is in a narrow space, so tin deposition causes a significant increase in collector degradation.

[00014] As mentioned above, a scrubber can be added to an area such as the upper part of the blade to condense tin contained in the steam from the steam. Keeping the surface of the scrubber above the melting point of tin allows liquid tin to flow through the blades and reach the receptacle. However, there is still the risk that the liquid tin in the scrubber will splash on the collector and drip from the groove into the collector, increasing collector deterioration. There is also a problem in maintaining the scrubber at a temperature higher than the melting point of tin. If the temperature of the scrubber is below the melting point of tin, tin will solidify and clog the scrubber. Changing the scrubber geometry, for example by changing the size and tilt of the scrubber blades, may improve performance, but completely eliminates the tendency for the scrubber to splash on the collector or cold surface and clog the ejector. It cannot be resolved.

[00015] Also, the process of generating EUV light can cause target material to deposit on the walls of the vessel. Controlling target material deposition on the walls of the vessel is important for achieving an acceptable length of life of the EUV source in operation. Also, managing the target material flux from the irradiated area is important to ensure that the waste target material mitigation system works as intended.

[00016] The following is a simplified overview of one or more embodiments in order to gain a basic understanding of those embodiments. This overview does not provide a broad overview of all possible embodiments and is not intended to identify the key or essential elements of all embodiments, and any or all of them. It is also not intended to limit the scope of the embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to a more detailed description presented later.

[00017] According to one embodiment, different tin management techniques are used for the "tin path", i.e., different parts of the path from the chamber liner to the imaging relay mirror that redirects the light exiting the chamber. A combination of solid and liquid tin techniques is used with the discharge manifold to control tin diffusion and collection. Identify the zones in the effluent and use appropriate techniques to handle the effluent flow in each of these zones based on different requirements.

[00018] According to another aspect of the embodiment, an apparatus for generating EUV radiation is disclosed. The device is a vessel and a wall of the vessel configured to release the residual target material collected at the first position and the first position configured to collect the residual target material from the irradiation area. The residual target material collecting surface having a second position shielded from the inside of at least a part of the surface and the residual target material collecting surface at the first position are maintained at a temperature lower than the melting point of the target material and the second position. It comprises a temperature controller configured to maintain a temperature above the melting point of the target material at the position of. The residual target material collection surface may include the surface of the belt. The belt can be cooled in the first position and heated in the second position. The device may further comprise at least one scrubber positioned adjacent to the belt in the second position and configured to remove residual target material from the belt. At least one scrubber can be positioned so that the residual target material removed from the belt flows to the receptacle by gravity. The device may further include a chamber discharge manifold that communicates fluidly with the chamber. The chamber discharge manifold has a liner, and at least a portion of the liner can be heated. The residual target material collection surface may include a shield. The shield can be cooled in the first position and heated in the second position. The shield may be configured to pivot from a first position to a second position. The shield may be configured to move laterally from a first position to a second position. The second position can be selected so that the molten residual target material flows from the shield to the receptacle by gravity. The device may further include a chamber discharge manifold that communicates fluidly with the chamber. The chamber discharge manifold has a liner, and at least a portion of the liner can be heated.

[00019] According to one aspect of the embodiment, a method of collecting residual target material in an apparatus for generating EUV radiation is disclosed. This method is a step of accumulating the residual target material on the surface in the first position, where the surface is at a temperature lower than the melting point of the target material, the step and the surface, the surface of which is below the melting point of the residual target material. It includes a step of melting the residual target material by moving it to a second position, which is also at a higher temperature, and a step of removing the molten residual target material from the surface. The step of removing the melt residue target material from the surface may include rubbing the melt residue target material from the surface. The step of removing the molten residual target material from the surface may include flushing the molten residual target material from the surface. The removal step may further include the flow of the removed molten residual target material through the receptacle.

[00020] Further embodiments, features, and advantages of the present invention, as well as the structure and operation of the various embodiments, are described in detail below with reference to the accompanying drawings.

[00021] Schematic and out-of-scale diagram showing the overall broad concept of a laser-generated plasma EUV source system according to an aspect of the present invention. [00022] Non-scaled view showing possible configurations of a container and discharge system used in a laser-generated plasma EUV source system according to an aspect of the present invention. [00023] A non-scaled diagram showing a possible configuration of a container target material control system used in a laser-generated plasma EUV source system according to one aspect of the invention. [00024] A non-scaled diagram showing a possible configuration of a target material control system for a throat portion of a container used in a laser-generated plasma EUV source system according to an embodiment of the present invention. Is. [00025] An out-of-scale diagram showing another possible configuration of a target material control system for the tubular portion of a vessel used in a laser-generated plasma EUV source system according to an embodiment of the present invention. .. [00026] In a non-scaled diagram showing another possible configuration of a target material control system element for the tubular portion of a vessel used in a laser-generated plasma EUV source system according to an embodiment of the present invention. is there. [00027] It is a top view of the configuration of FIG. 5A. [00028] Non-scaled view showing additional elements of a target material control system element for the tubular portion of a container used in a laser-generated plasma EUV source system according to an embodiment of the present invention.

[0029] Another feature and advantage of the invention and the structure and operation of various embodiments of the invention will be described in detail below with reference to the accompanying drawings. It should be noted that the invention is not limited to the particular embodiments described herein. Such embodiments are described herein for purposes of illustration only. One of ordinary skill in the art will readily come up with further embodiments based on the teachings contained herein.

[00030] Various embodiments will now be described with reference to the drawings. Point to similar elements with similar reference numbers throughout the drawing. The following description describes a number of specific details to facilitate a complete understanding of one or more embodiments for purposes of explanation. However, in some or all cases, it is clear that any of the embodiments described below can be implemented without adopting such specific design details described below. Will. In some cases, well-known structures and devices are shown in the form of block diagrams to facilitate the description of one or more embodiments.

[00031] Before elaborating on such embodiments, it would be useful to present an exemplary environment in which the embodiments of the present invention can be practiced. In the following description and claims, "up", "down", "top", "bottom", "vertical", "horizontal (horizontal)" Terms such as "horizontal)" may be used. These terms are intended to indicate only relative orientation, not absolute orientation, such as orientation to gravity, unless otherwise indicated.

[00032] First, with reference to FIG. 1, a schematic diagram of an exemplary EUV source, such as, for example, a laser-generated plasma EUV source 10, is shown according to an embodiment of the present invention. As shown, the EUV source 10 can include a pulsed or continuous laser source 22. This may be, for example, a pulsed gas discharge CO ₂ laser source that produces a 10.6 μm or 1 μm radiated beam 12. The pulsed gas discharge CO ₂ laser source may have DC or RF excitation operating at high power and high pulse repetition rate.

[00033] The EUV source 10 also includes a target delivery system 24 for delivering the target material in the form of droplets or continuous liquid streams. In this example, the target material is a liquid, but it may be a solid or a gas. The target material can be composed of tin or tin compounds, but other materials can also be used. In the system shown, the target material delivery system 24 introduces a droplet 14 of the target material into the irradiation region 28 inside the vacuum chamber 26. Here, the target material can be irradiated to generate plasma. The vacuum chamber 26 can include a liner. In some cases, the target material is charged to allow the target material to be guided towards or away from the irradiation area 28. As used herein, the irradiation area is an area where or is intended to cause irradiation of the target material, and is an irradiation area even when irradiation is not actually occurring. It should be noted that The EUV light source can also include a beam steering system 32.

[00034] The components in the illustrated system are arranged such that the droplet 14 travels substantially horizontally. The direction from the laser source 22 toward the irradiation region 28, that is, the nominal propagation direction of the beam 12, can be considered as the Z axis. The path through which the droplet 14 travels from the target material delivery system 24 to the irradiation region 28 can be considered as the X-axis. Therefore, the figure in FIG. 1 is perpendicular to the XZ plane. The orientation of the EUV radiation source 10 is preferably rotated with respect to gravity as shown. The arrow G indicates a preferred orientation with respect to the lower part of gravity. This orientation applies to EUV sources, but not necessarily to optically downstream components such as scanners. Also, although a system is illustrated in which the droplets 14 travel substantially horizontally, the droplets either travel vertically or at 90 degrees (horizontal) and 0 degrees (vertical) with respect to gravity. It will be appreciated by those skilled in the art that other configurations that travel at angles between (including these angles) are also available.

[00035] The EUV radiation source 10 can include an EUV light source controller system 60 and a laser emission control system 65 as well as a beam steering system 32. The EUV source 10 can also include a detector, such as a target position detection system, which may include one or more droplet imagers (imager) 70. The droplet imager generates, for example, an output indicating the absolute or relative position of the target droplet with respect to the irradiation region 28, and provides this output to the target position detection feedback system 62.

As shown in FIG. 1, the target material delivery system 24 can include a target delivery control system 90. The target delivery control system 90 operates in response to a signal such as, for example, the target error described above, or some amount derived from the target error given by the system controller 60, of the target droplet 14 passing through the irradiation area 28. Adjust the route. This can be achieved, for example, by repositioning the point at which the target delivery mechanism 92 releases the target droplet 14. The droplet release point can be repositioned, for example, by tilting the target delivery mechanism 92 or translating the target delivery mechanism 92 laterally. The target delivery mechanism 92 extends into the chamber 26, and preferably from the outside, a target material and a gas source for placing the target material in the target delivery mechanism 92 under pressure are supplied.

[00037] Continuing with FIG. 1, the source 10 may also include one or more optical elements. In the following studies, the collector 30 is used as an example of such an optical element, but the following studies also apply to other optical elements. The collector 30 may be a normal incidence reflectors, for example, it is implemented as a MLM, eg _{B 4 C, ZrC, Si 3} N 4, or additional thin barrier layer, such as a C is deposited on the surface, heat Effectively blocks the induced interlayer diffusion. Other substrate materials such as aluminum (Al) or silicon (Si) can also be used. The collector 30 can be in the form of a prolate ellipsoid, with a central opening passing through the laser emission 12 to reach the irradiation area 28. The collector 30 may be, for example, an ellipse in which the first focal point is in the irradiation region 28 and the second focal point is at the so-called intermediate point 40 (also referred to as the intermediate focal point 40). At intermediate point 40, EUV radiation can be output from the EUV source 10 and input to, for example, the integrated circuit lithography scanner 50. The integrated circuit lithography scanner 50 uses this radiation to process the silicon wafer workpiece 52 in a known manner, for example using a reticle or mask 54. The silicon wafer workpiece 52 is then further processed in a known manner to obtain an integrated circuit device.

[00038] The configuration of FIG. 1 also includes a temperature sensor 34. This is, for example, a thermocouple placed in the chamber 26 to measure the local temperature, i.e. the temperature of the gas in the chamber 26 in this sensor. Although FIG. 1 shows one temperature sensor, it will be appreciated that additional temperature sensors can be used. The temperature sensor 34 generates a signal indicating the measured temperature, which is supplied to the controller 60 as an additional input. The controller 60 generates a control signal to be supplied to the beam steering system 32 based on this temperature signal, at least in part.

[00039] Accumulation of target material debris on the wall of the container directly above the collector poses a risk of the target material dripping onto the collector. The black double arrow in FIG. 2 indicates the direction of debris propagation. White arrows indicate a preferred configuration for the flow of H ₂ in a direction away from the collector 30. Element 42 is a scrubber for removing contaminants from H _2. The arrow G indicates the direction of gravity. Also shown is line 13 showing the division between the radiation source 10 and the scanner 50.

[00040] FIG. 3 shows a chamber design with an asymmetric drain with a large tubular area. The design of FIG. 3 has two outlets 60. In this design, a large amount of tin can accumulate at position 70 on the wall of the exhaust manifold opposite this large tubular section. If this surface is maintained above the melting point of tin, the molten tin can splash on the collector.

[00041] In a system according to one embodiment of the present invention, the tin is melted or in a liquid state inside the chamber or at a location where it is unlikely or likely that the liquid tin will splash on the collector. Keep in. High flow conductance can be maintained and the exhaust gas is scrubbed. According to another aspect, tin can be emitted during the operation of the in situ radiation source.

[00042] An example of such a system is shown in FIG. 4A. Tin debris from the irradiated area 28 is captured by two heated scrubbers 80. These scrubbers 80 are located in each hot zone and are completely protected from splashing on the inner surface 84 of the chamber 26, including the liner 84, which at least partially covers the discharge plenum wall 86. Part 88 of the liner 84 adjacent to the scrubber 80 can be heated to a temperature above its melting point to “drip off” excess solid tin. These surfaces are also protected from splashing on the collector.

[00043] Further, as shown in FIG. 4A, this configuration includes an endless belt 90 covering a portion of the rear wall or outer wall 94 of the drain plenum. A cold (eg, water-cooled) plate 92 is sandwiched between the belts 90, which are in contact with or substantially in contact with each other to keep the surface at a temperature well below the melting point of tin. Therefore, the solid tin particles entering this area remain solid, and the tin vapor entering this area becomes solid.

[00044] The belt 90 can be continuously moved, intermittently moved, advanced stepwise at regular intervals, and the like so as to carry the solid tin to the high temperature scrubber 80. When the endless belt 90 hits the hot scrubber 80, the heated doctor blade melts the tin and the belt 90 can be rubbed clean, and the belt 90 returns to the deposition area for further tin collection. This configuration ensures that tin splashes do not hit the collector or liner. The belt 90 is preferably placed in an area where the highest tin deposit is expected, such as a tubular area.

[00045] Another example of such a system is shown in FIG. 4B. Again, tin debris from the irradiated area 28 is captured by two heated scrubbers 80 located in each hot zone that are completely protected from splashing on the inner surface 84 of the liner 86 and the collector. .. Further, as shown in FIG. 4B, this configuration includes a wedge-shaped diverter 96 positioned at the tubular outlet on the wall of the drain plenum. The induction device 96 directs the flow of debris from the irradiation area 28 (white arrow) to the discharge manifold portion shielded from the irradiation area 28 (curved arrow). The direction of splash of molten tin being carried / deposited tends to be towards the scrubber 80 but not back inside the vacuum vessel. Due to its shape, the induction device 94 directs the exhaust gas and the carried debris flow away from the rear wall of the tubular outlet and directly into the scrubber. Normally, the induction device 96 is cooled to a temperature lower than the melting point of the target material, but it is also possible to heat the induction device 96 to a temperature higher than the melting point of tin to allow solid tin accumulated on the induction device 96 to flow to the tin drain. Most of the tin produces a splash perpendicular to the surface of the inductive device 96 that points away from the interior of the chamber 26, which greatly limits the amount of splash that goes into the optics within the tool.

[00046] Some attention must be paid to the roof of the liner at the opening to the large tubular section. These roof and floor areas are usually sloping and recessed to protect collectors / liners as much as possible.

[00047] It is also possible to cover other areas with high sedimentation with a water cooling shield. The shield can be rotated behind the opening by a hinge for dripping. Such a configuration is shown in FIGS. 5A and 5B. FIG. 5A shows a tubular area with a shield 110. The shield 110 is connected to the wall of the tubular portion by a hinge 112 and can be pivoted behind the opening (pivot) and placed in a position where tin is dropped by heating (indicated by a virtual line). FIG. 5B is a top view of the configuration of FIG. 5A, showing the rotation of the shield 110 around the hinge 112. These shields 110 can be positioned to minimize adverse effects on conductivity and to prevent liquid tin splashes from having an open path to the collector or liner.

[00048] Modifications to the above embodiments that represent the spirit of this disclosure are possible. According to one aspect of the disclosed embodiment, the solid tin temperature surface is presented in an area where the liner and collector may be splashed. Tin can then be removed by any of several methods, including surface temperature cycling, i.e., temporarily raising the surface temperature above the melting point of tin. Alternatively or additionally, the surface can be moved to a shielding position for dripping or covered during dripping. According to another aspect, the liquid tin is recovered from the gas stream (washed out) and delivered to a suitable isolation position for drain (eg, no open path to the collector or liner). The upstream wall of the scrubber can be maintained at a temperature at which tin can drip. According to another aspect, in areas with extremely high deposits, temperature cycling, moving the liner portion to a safe position for dripping, ion generation for cleaning and to maintain a clean state, or during dripping. A partial cover can be used.

[00049] Figure 6 shows the tubular section 100 located as high as possible in the chamber between on and off of the plasma, i.e., to limit the amount of debris excess when the plasma is generated and when it is not generated. An embodiment in which is moved is shown. This increases the debris discharge efficiency and limits the amount of debris that accumulates on the inner wall surface. In this embodiment, the endless belt 90 of the embodiment of FIG. 4A can be used or the heating plate can be placed at the output of the tubular portion 100. The drain manifold is made circular (pipe-shaped) and can therefore have a round scrubber 110 rather than a rectangular scrubber. The tin drain 115 collects molten tin and sends it to a tin bucket or receptacle 117. The freeze valve 119 allows the tin receptacle 117 to be emptied through the conduit 121 without interfering with the operation of the radiation source. The tin drain can be placed on either side of the source.

[00050] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purposes of describing the above embodiments, and those skilled in the art will be able to make many other combinations and sorts of various embodiments. Will be acknowledged. Accordingly, the embodiments described are intended to include all such alternatives, modifications, and modifications that fall within the spirit and scope of the appended claims. Further, as long as the term "include" is used in either the form for carrying out the invention or the claims, such term is claimed by the term "comprising". It is intended to be inclusive, as it is interpreted when used as a transition term in. Further, the elements of the described embodiments and / or embodiments may be described or claimed in the singular, but the plural is also envisioned unless a limitation to the singular is explicitly stated. Furthermore, unless otherwise specified, all or part of any other aspect and / or embodiment may be used with all or part of any other aspect and / or embodiment.

[00051] Other aspects of the invention are described in the numbered provisions below.
1. 1. A device for generating EUV radiation,
With the container
From a first position configured to collect residual target material from the irradiation area and from inside at least a portion of the vessel wall configured to release the residual target material collected in the first position. A residual target material collection surface having a shielded second position, and
A temperature controller configured to keep the residual target material collection surface at a temperature below the melting point of the target material in the first position and above the melting point of the target material in the second position.
A device equipped with.
2. The device according to Clause 1, wherein the residual target material collecting surface includes the surface of the belt.
3. 3. The device according to clause 2, wherein the belt is cooled in the first position and heated in the second position.
4. The device of clause 2, further comprising at least one scrubber positioned adjacent to the belt in the second position and configured to remove residual target material from the belt.
5. The device of clause 4, wherein the at least one scrubber is positioned so that the residual target material removed from the belt flows to the receptacle by gravity.
6. The device of Clause 1, further comprising a chamber discharge manifold that communicates fluid with the chamber.
7. The device according to clause 6, wherein the chamber discharge manifold has a liner and at least a part of the liner is heated.
8. The device according to Clause 1, wherein the residual target material collection surface includes a shield.
9. The device according to clause 8, wherein the shield is cooled in the first position and heated in the second position.
10. The device of clause 8, wherein the shield is configured to pivot from a first position to a second position.
11. The device of clause 8, wherein the shield is configured to move laterally from a first position to a second position.
12. The device according to clause 8, wherein the second position is selected so that the molten residual target material flows from the shield to the receptacle by gravity.
13. The device according to clause 8, further comprising a chamber discharge manifold that communicates fluid with the chamber.
14. 25. The device of clause 13, wherein the chamber discharge manifold has a liner and at least a portion of the liner is heated.
15. A method of collecting residual target material in a device for generating EUV radiation.
The step of accumulating residual target material on the surface in the first position, wherein the surface is at a temperature lower than the melting point of the target material.
A step of moving the surface to a second position where the surface is at a temperature higher than the melting point of the residual target material to melt the residual target material.
The steps to remove the molten residual target material from the surface,
How to include.
16. The method of clause 15, wherein the step of removing the melt residual target material from the surface comprises rubbing the melt residual target material from the surface.
17. The method of Clause 15, wherein the step of removing the molten residual target material from the surface comprises flushing the molten residual target material from the surface.
18. 25. The method of clause 15, further comprising a step of removing the removed molten residual target material through a receptacle.

Claims (18)

A device for generating EUV radiation,
With the container
A first position configured to collect residual target material from the irradiation area and at least a portion of the vessel wall configured to release the residual target material collected in said first position. A residual target material collection surface having a second position shielded from the inside, and
A temperature configured to keep the residual target material collecting surface at a temperature lower than the melting point of the target material at the first position and at a temperature higher than the melting point of the target material at the second position. With the controller
A device equipped with. The device according to claim 1, wherein the residual target material collecting surface includes a surface of a belt. The device according to claim 2, wherein the belt is cooled in the first position and heated in the second position. The apparatus of claim 2, further comprising at least one scrubber positioned adjacent to the belt in the second position and configured to remove residual target material from the belt. The device of claim 4, wherein the at least one scrubber is positioned such that the residual target material removed from the belt flows to the receptacle by gravity. The device according to claim 1, further comprising a chamber discharge manifold that communicates fluidly with the chamber. The device according to claim 6, wherein the chamber discharge manifold has a liner, and at least a part of the liner is heated. The device according to claim 1, wherein the residual target material collecting surface includes a shield. The device of claim 8, wherein the shield is cooled in the first position and heated in the second position. The device according to claim 8, wherein the shield is configured to pivot from the first position to the second position. The device according to claim 8, wherein the shield is configured to move laterally from the first position to the second position. The device of claim 8, wherein the second position is selected so that the molten residual target material flows from the shield to the receptacle by gravity. The device according to claim 8, further comprising a chamber discharge manifold that communicates fluid with the chamber. 13. The apparatus of claim 13, wherein the chamber discharge manifold has a liner, and at least a portion of the liner is heated. A method of collecting residual target material in a device for generating EUV radiation.
A step of accumulating residual target material on a surface at the first position, wherein the surface has a temperature lower than the melting point of the target material.
A step of moving the surface to a second position where the surface is at a temperature higher than the melting point of the residual target material to melt the residual target material.
The step of removing the molten residual target material from the surface and
How to include. 15. The method of claim 15, wherein the step of removing the melt residual target material from the surface comprises rubbing the melt residual target material from the surface. 15. The method of claim 15, wherein the step of removing the melt residual target material from the surface comprises flowing the melt residual target material from the surface. 15. The method of claim 15, further comprising the step of flushing the removed molten residual target material through the receptacle after the removal step.

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