Debris handling apparatus and method for extreme ultraviolet light sources

Abstract

A debris treatment apparatus controls debris in a controlled environment interior of a chamber of an extreme ultraviolet (EUV) radiation source, wherein generated EUV light is transmitted along an optical axis within the chamber interior. The debris handling device includes a linear array of fins and a port liner. The fins are arranged relative to each other such that grooves are formed between adjacent fins of the array, each groove comprising an output groove channel and an input groove channel facing the exhaust pump such that a flow direction is defined from the input groove channel to the output groove channel. The port gasket defines a fluid port including an upstream side located outside and in fluid communication with the inside of the chamber, and a downstream side adjacent to and in fluid communication with the input trench channel.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. application No. 63 / 397,794 filed on August 12, 2022 and U.S. application No. 63 / 426,921 filed on November 21, 2022, the entire contents of both patent applications are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to apparatus and methods for handling debris generated in an extreme ultraviolet ("EUV") light source during plasma generation of EUV radiation. Background Art

[0004] 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 having a wavelength of about 13.5 nm, can be used in lithography processes to produce extremely small features in or on a substrate, such as a silicon wafer. Methods for generating EUV radiation include converting a target material into a plasma state. The target material includes at least one element, such as xenon, lithium, or tin, having one or more emission lines in the EUV portion of the electromagnetic spectrum. The target material can be a solid, a liquid, or a gas. In one such method, generally referred to as laser produced plasma ("LPP"), the desired plasma can be produced using a "source" laser, which is typically a CO 2 laser that emits infrared light at a wavelength of or about 10,600 nanometers (nm). 2 A laser, irradiates a target containing one or more EUV line emitting elements with one or more light pulses. The plasma is typically generated in a sealed "source container", which is typically a vacuum chamber. Summary of the invention

[0005] In some general aspects, a debris handling device is used to control debris within a controlled environment chamber of an extreme ultraviolet (EUV) radiation source. The debris handling device includes an array of v-shaped fins, the fins being arranged relative to each other so that v-shaped grooves are formed between pairs of adjacent fins of the array. Each v-shaped fin includes two segments arranged at an obtuse angle to each other, and each v-shaped groove includes an input groove channel facing the interior of the chamber and an output groove channel facing the exhaust pump, so that the flow direction is defined from the input groove channel to the output groove channel. The angle between each segment and the flow direction is less than 20°.

[0006] Implementations may include one or more of the following features. For example, each v-shaped fin may have a thickness in the range of 1 mm-3 mm. The distance between each adjacent fin may be in the range of 9 millimeters to 20 millimeters (mm), and the length of each v-shaped fin along the flow direction may be at least 50 mm, at least 75 mm, at least 100 mm, or at least 120 mm.

[0007] Each v-shaped fin may be made of a first sub-fin and a second sub-fin. The interface between the first sub-fin and the second sub-fin may include a portion that is linearly oriented at a certain angle relative to the flow direction. The debris disposal device may also include a gasket in which the v-shaped fin array is installed. The first sub-fin may be mounted to the first wall of the gasket, and the second sub-fin may be mounted to the second wall of the gasket. The gasket may include a material different from the material of the v-shaped fin. The gasket may be made of stainless steel, and the v-shaped fin may be made of molybdenum. Adjacent pairs of v-shaped fins may be mounted to the gasket together at the same connection interface. The v-shaped fins may each be mounted to the gasket at a plurality of connection interfaces, each of which includes bolts, nuts and spring washers passing through the gasket and the v-shaped fin.

[0008] Each v-shaped fin may include a concave beveled edge at an input groove channel of an adjacent v-shaped groove. The debris disposal device may include a drain device in fluid communication with the v-shaped groove, the drain device being configured to remove debris collected by the v-shaped fin array. Each v-shaped fin may include a refractory metal or metal alloy, or be made of a refractory metal or metal alloy. The angle between each segment and the flow direction may be greater than 0° and less than 20°; greater than 5° and less than 15°; or greater than 10° and less than 13°.

[0009] In other general aspects, a debris handling device is used to control debris inside a controlled environment of a chamber of an extreme ultraviolet (EUV) radiation source, wherein the generated EUV light is transmitted along an optical axis inside the chamber. The debris handling device includes: a linear fin array and a port liner. The fins are arranged relative to each other so that grooves are formed between adjacent fins of the array. Each groove includes an output groove channel and an input groove channel facing an exhaust pump, so that the flow direction is defined as from the input groove channel to the output groove channel. The port liner defines a fluid port, which includes an upstream side located outside the chamber and in fluid communication with the interior of the chamber, and a downstream side adjacent to the input groove channel and in fluid communication with the input groove channel.

[0010] Implementations may include one or more of the following features: For example, all flow directions in the grooves may be the same.

[0011] The upstream side of the port liner may be in fluid communication with a discharge opening on a wall of the chamber by means of a chamber passage outside the chamber. The chamber passage may have an annular shape and extend around an outer circumference outside the chamber. The upstream side of the port liner may be positioned at an angle of at least 90° to the discharge opening with respect to the outer circumference outside the chamber.

[0012] The debris disposal device may also include a drain configured to drain debris collected in the linear fin array from the linear fin array. The upstream side of the port liner may be in fluid communication with a drain opening in a wall of the chamber by means of a chamber channel outside the chamber, and the drain opening may be positioned under gravity below the fluid port of the port liner, and the drain device may include at least a portion of the fluid port of the port liner and the chamber channel. The drain opening may be positioned under gravity above the fluid port of the port liner, and the drain device may include a drain port in fluid communication with the output groove channel.

[0013] EUV light may be transmitted within the chamber along an optical axis from a primary focus to a secondary focus, neither of which is within the line of sight of the upstream side of the fluid port.

[0014] Each fin may be a v-shaped fin including two segments arranged at an obtuse angle to each other, and each groove may be a v-shaped groove. Each v-shaped fin may be made of a first sub-fin and a second sub-fin.

[0015] The debris disposal device may further include an array liner in which the fin array is mounted, the array liner and the port liner being sealingly connected.

[0016] Each fin may include a first sub-fin and a second sub-fin separated from each other. The debris disposal device may also include an array pad in which the fin array is mounted. The first sub-fin may be mounted to the first wall of the array pad by means of a detachable connector, and the second sub-fin may be mounted to the second wall of the array pad by means of a detachable connector. The gap between the first sub-fin and the second sub-fin extends in a direction that is not parallel to the edge of the first sub-fin mounted to the first wall. The range of the gap along a direction perpendicular to the flow direction may be generally constant throughout the gap.

[0017] Each fin may include a concave bevel at the input groove channel of an adjacent groove. The concave bevel may be formed with two bevels defining a notch facing the fluid port. Each fin may include a convex bevel at the output groove channel of an adjacent groove.

[0018] The debris handling device may further include a heater configured to maintain the temperature of the fins above a melting point of debris generated during EUV light generation. The debris handling device may further include an array pad in which the fin array is mounted, wherein the heater may be in thermal contact with the array pad and the port pad.

[0019] Each fin may comprise or be made of a refractory metal or metal alloy.

[0020] In other general aspects, an extreme ultraviolet (EUV) radiation source container includes: a chamber, a control system, a debris disposal device and an exhaust opening. The chamber includes one or more walls defining the interior of the chamber. A primary focus where a plasma is generated by light pulses interacting with a target and a secondary focus where EUV radiation generated by the plasma is focused are within the chamber, and in use, EUV light is transmitted from the primary focus to the secondary focus along an optical axis. The control system is configured to maintain the temperature of the chamber and the interior of the chamber below the melting point of the material of the target and to flow a purge gas away from the primary focus. The debris disposal device includes a fluid port located outside the chamber and includes an upstream side in fluid communication with the interior of the chamber and a downstream side in fluid communication with a debris capture array. The exhaust opening is in fluid communication with the interior of the chamber at a first end and in fluid communication with the upstream side of the fluid port at a second end.

[0021] Implementations may include one or more of the following features.For example, the control system may be configured to maintain a temperature of at least a portion of the debris disposal device above a melting point of the material of the target and the material of the debris generated within the chamber.

[0022] In other general aspects, a method of disposing of debris generated inside a controlled environment of a chamber of an extreme ultraviolet (EUV) radiation source is performed. The method includes: passing a gas flow through an exhaust opening in a wall of the chamber, including directing the gas flow from inside the chamber through the exhaust opening to outside the chamber; directing the gas flow from the exhaust opening to a debris disposal device outside the chamber; collecting debris within the gas flow at the debris disposal device; and discharging the debris collected by the debris disposal device through the exhaust device.

[0023] Implementations may include one or more of the following features. For example, by directing the airflow from the collector in the chamber to the discharge opening, the airflow can be directed from the chamber to the discharge opening. By passing the chamber channel located outside the upstream side of the fluid port of the debris disposal device around at least a portion of the outer circumference of the chamber, the airflow can be directed from the discharge opening to the debris disposal device outside the chamber. The debris in the airflow can be collected at the debris disposal device, which is achieved by passing the debris through the input groove channel of a plurality of grooves, and collecting the debris in each groove, and the plurality of grooves are formed between pairs of adjacent fins in a linear fin array. The debris collected by the debris disposal device can be discharged by manipulating the debris flow through each corresponding groove and entraining the debris in the corresponding groove. The debris collected by the debris disposal device can be discharged by passing the collected debris along a discharge path overlapping with the gas path of the guided airflow. The debris collected by the debris disposal device can be discharged by passing the collected debris along a discharge path separated from the gas path of the guided airflow.

[0024] The method may further include compensating for thermal expansion mismatch between the fin and the pad in which the fin is mounted.The airflow may be directed from the discharge opening to the debris disposal device outside the chamber by directing the airflow along a single path to the debris disposal device.

[0025] In other general aspects, a debris handling device for controlling debris within a controlled environment chamber of an extreme ultraviolet (EUV) radiation source. The debris handling device includes an array of v-shaped fins arranged relative to each other so that a v-shaped groove is formed between adjacent fins of the array. Each v-shaped fin includes two segments arranged at an obtuse angle to each other, and each v-shaped groove includes an input groove channel facing the interior of the chamber and an output groove channel facing the exhaust pump, so that the flow direction is defined from the input groove channel to the output groove channel. Each v-shaped fin includes a concave bevel at the input groove channel of adjacent v-shaped grooves.

[0026] Implementations may include one or more of the following features. For example, a concave bevel may be formed with two bevels defining a notch facing the interior of the chamber. Each v-shaped fin may include a convex bevel at an output groove channel of an adjacent v-shaped groove. The debris disposal device may include a heater configured to maintain the temperature of the v-shaped fin above the melting point of the material in the debris. The debris disposal device may include a pad in which the v-shaped fin array is mounted, and the heater may be in thermal contact with the pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1A A schematic side cross-sectional view of a debris handling device configured for a chamber relative to an extreme ultraviolet radiation source;

[0028] Figure 1B for Figure 1A A schematic cross-sectional view of the debris disposal device along line 1B-1B;

[0029] Figure 2 FIG1 is a schematic cross-sectional view of an implementation of the debris disposal device;

[0030] Figure 3A For Figure 1 and Figure 2 A perspective view of a port liner and an array liner of a debris handling device;

[0031] Figure 3B Observed along the flow direction Figure 3A A perspective view of a port pad and an array pad;

[0032] Figure 3C for Figure 3A and Figure 3B A top cross-sectional view of a port liner, an array liner, and a fin array within the array liner;

[0033] Figure 3D for Figure 3C A close-up view of the array’s fins;

[0034] Figure 3E for Figures 3A-3C A side cross-sectional view of an array pad and fin array, with the flow direction being in the page;

[0035] Figure 4A is a perspective view of the implementation of a single fin in an array;

[0036] Figure 4B for Figure 4A A side view of a single fin;

[0037] Figure 4C For along Figure 4B Cross-sectional view taken along line 4C-4C;

[0038] Figure 5A is a perspective view of the implementation of paired fins in an array;

[0039] Figure 5B for Figure 4A A side view of the paired fins;

[0040] Figure 5C For along Figure 5B Cross-sectional view taken along midline 5C-5C;

[0041] Figure 5D for Figure 5B A cross-sectional view of a portion 5D of a pair of fins, showing details of a sub-connection interface connecting the pair of fins to the array;

[0042] Figure 5E for Figure 5A An exploded perspective view of an embodiment of a pair of fins;

[0043] Figure 6 for Figure 2 , a schematic cross-sectional view of an implementation of the debris disposal device in FIGS. 3 and 4 ;

[0044] Figure 7 for Figure 2 , a schematic cross-sectional view of an implementation of the debris disposal device in FIGS. 3 and 4 ; and

[0045] Figure 8 for Figure 1A and Figure 1B as well as Figure 2 A perspective view of a port liner and an array liner of an implementation of a debris handling device and including a heater. DETAILED DESCRIPTION

[0046] refer to Figure 1A and Figure 1B , a debris handling device 100 is used to control debris in a controlled environment interior 161 of a chamber (or container) 162 of an extreme ultraviolet (EUV) radiation source 160. The debris handling device 100 enables the removal of debris from the interior 161 of the chamber 162 and is therefore used to clean the interior 161 of the chamber 162. In addition, due to the design and placement of the debris handling device 100, it is more durable and more efficient than existing debris handling devices. In the EUV radiation source 160, generated EUV light 163 is transmitted from a primary focus PF to a secondary focus SF along an optical axis OA within the chamber interior 161. The debris handling device 100 controls debris within the interior 161 by removing debris from the interior 161 and transporting the debris to one or more locations outside the interior 161. The EUV radiation source 160 is shown in a schematic cross-section in the XZ plane, with the X axis extending up and down in the plane of the page, and the Z axis extending left and right in the plane of the page, and the Z axis is aligned with the optical axis OA. The chamber 162 may be symmetric about the Z-axis such that it comprises a conical shape tapering from the primary focus PF to the secondary focus SF. Depending on the design of the EUV radiation source 160, the optical axis OA (and the Z-axis) may be positioned in different directions relative to the direction of gravity.

[0047] Debris may be formed during the production of the EUV lamp 163, as shown below. Targets 164 delivered to the irradiation site 165 (at the primary focus PF) individually interact with one or more light pulses in the beam 166. From this interaction, a plasma 167 is generated, which produces EUV light 163. The EUV light 163 is collected by a collector 168, which may be a near-normal incidence collector mirror defined by an optical axis OA and having a reflective surface 168r, which may be in the form of a prolate spheroid (i.e., an ellipse rotated about its major axis). In this manner, the collector 168 defines a primary focus PF at the irradiation site 165 and a secondary focus SF at the exit of the chamber 162.

[0048] The target 164 includes an EUV emitting target material such as, but not limited to, tin, lithium, xenon, or a combination thereof. The target 164 at the irradiation location 165 may be in the form of a liquid droplet, or may be a solid particle or a solid particle contained in a liquid droplet. For example, elemental tin may be present as a target in the following forms: pure tin; a tin compound such as SnBr; 4 SnBr 2 SnH 4 ; tin alloys, such as tin-gallium alloys, tin-indium alloys, or tin-indium-gallium alloys; or combinations thereof. During the generation of EUV light 163, energetic ions and / or particles and target material or vapor containing target material may be formed. For example, target material particles and energetic ions and vapor are byproducts of a light-based evaporation or ablation process that may occur when the target 164 interacts with the pulses of the light beam 166, and these byproducts are debris in the interior 161 of the chamber 162. Generally, the debris contaminates the reflective surface 168r of the collector 168. For example, particles of target material and energetic ions and vapor (all of which are debris) may cause physical damage and localized heating of the reflective surface 168r of the collector 168. The debris disposal device 100 is designed to be combined with other components that direct the debris in the interior 161 of the chamber 162 to the debris disposal device 100 to remove the debris from the interior 161 of the chamber 162 and prevent the debris from re-entering the interior 161 after being removed.

[0049] The debris handling device 100 includes a linear array 105 of fins 106. The fins 106 are arranged relative to each other so that the grooves 107 (or gaps) ( Figure 1B) are formed between pairs of adjacent fins 106 of the array. Each groove 107 is defined by a pair of adjacent fins 106. A planar input groove channel 107i and a planar output groove channel 107o facing the exhaust pump 108 define the input and output of each groove 107. A local flow direction F is defined from the input groove channel 107i and extends from the input groove channel 107i to the output groove channel 107o. When debris enters the array 105, the flow direction F generally controls the flow of debris and is generally the same for all grooves 107 defined in the array 105. The fins 106 and grooves 107 are arranged along the entry and / or exit Figure 1B The plane of the page and extends along the local flow direction F. Figure 1A In the embodiment of the present invention, the fins 106 and grooves 107 extend along the plane of the page. The array 105 of fins 106 is mounted inside and onto the array pad 109 by means of one or more connection interfaces 103. The array 105 is housed in the cavity 109c of the pad 109.

[0050] The debris disposal device 100 includes a port liner 115 that defines a fluid opening or port 116. The fluid port 116 includes an upstream side 117u located outside 169 of the chamber 162. The fluid port 116 is in fluid communication with the chamber interior 161 by means of the upstream side 117u. The fluid port 116 includes a downstream side 117d that is in fluid communication with the input groove channel 107i of the groove 107. The port liner 115 and the array liner 109 are sealingly connected to each other so that material (e.g., debris) within the fluid port 116 is forced to flow through the array 105 of the fins 106 and does not escape from between the port liner 115 and the array liner 109.

[0051] The upstream side 117u of the fluid port 116 of the port liner 115 is in fluid communication with the exhaust opening 120 in the wall 170 of the chamber 162. In some implementations, such as also shown below Figure 7 , the fluid connection between the upstream side 117u of the fluid port 116 and the discharge opening 120 is by means of a circumferential chamber passage 121 located at the exterior 169 of the chamber 162. The chamber passage 121 is defined within or by a circumferential channel structure 122. Both the chamber passage 121 and the structure 122 may have an annular shape such that both extend around at least a portion of the outer circumference of the wall 170 of the chamber 162. For example, and with specific reference to Figure 1B, the upstream side 117u of the port liner 115 can be positioned at an angle Ω (in the XY plane) relative to the outer circumference of the exhaust opening 120 around the wall 170 (or the chamber exterior 169). The angle Ω can be any value. For example, the angle Ω can be at least 45 degrees, at least 60 degrees, at least 70 degrees, at least 90 degrees, or at least 120 degrees. As another example, the angle Ω can be any value within a range between 45° and 180°. In other implementations, such as the following Figure 6 As shown, the fluid connection between the upstream side 117u of the fluid port 116 and the exhaust opening 120 is direct. In both implementations, the port liner 115 is located far enough from the optical axis OA that both the primary focus PF and the secondary focus SF are not in the line of sight of the upstream side 117u of the fluid port 116.

[0052] In both implementations, the debris disposal device 100 is disposed outside (or outside) the chamber 162 and is therefore removed from the interior 161. However, the debris disposal device 100 is in fluid communication with the interior 161 of the chamber 162 and is capable of receiving debris generated within the interior 161 of the chamber 162. Therefore, it is not necessary to create an environment in the interior 161 of the chamber 162 to specifically accommodate the design of the debris disposal device 100. For example, the interior 161 can contain a gas flow that can serve as a buffer gas for the debris and / or vapors emitted from the irradiation site 165. In some implementations, hydrogen (H 2 ) is used as the hydrogen flow in interior 161 because hydrogen is relatively transparent to EUV radiation having a wavelength of approximately 13.5 nanometers (nm). Hydrogen can be introduced into interior 161 to slow down and / or direct high-energy fragments (such as ions, atoms, and clusters) of target material generated by irradiation of target 164 at irradiation location 165 and the resulting plasma 167. The fragments (which are highly energetic) are generated by interacting with gas molecules (H 2 The gas flow can be directed to prevent debris generated at the irradiation position 165 from reaching the reflective surface 168r of the collector 168. Therefore, the gas flow can reduce damage to the collector 168 caused by deposition of vapor deposition, implantation, and sputtering target materials.

[0053] When using a tin or tin-containing target 164, the use of hydrogen as a gas flow for the tin target 164 can cause another potential source of contamination of the interior 161 of the chamber 162. In particular, when hydrogen bubbles form and grow in or under the molten tin and then burst, the molten tin can be ejected or ejected from the surface coated with or coated with molten tin in the interior 161. One way to prevent tin splashing is to prevent the molten target material from accumulating on the surface of the interior 161 of the chamber 162 by maintaining the surface temperature below or far below the melting point of the target material. The melting point of tin is about 232°C. For example, some surfaces of the object or some parts of the interior 161 can be maintained at a temperature below 232°C, or a temperature in the range of about 50°C to about 110°C. Any tin deposited on the surface maintained at this temperature remains in solid form and prevents or prevents splashing. By moving the debris disposal device 100 (particularly the linear array 105 of the fins 106) out of the interior 161, it is possible to maintain the surface and the interior 161 at such a low temperature.

[0054] Deposits on cold surfaces within the interior 161 can shorten the time between uses of the EUV radiation source 160. By using a gas flow within the interior 161, the growth of such deposits on cold surfaces and the accumulation of liquid tin on the surfaces can be reduced. Different gas flows can be used. For example, one or more gas flows can be directed along the reflective surface 168r of the collector 168. As another example, one or more gas flows can be directed through holes that are generally perpendicular to the surface to be protected in the interior 161. The gas flow can be directed through one or more walls 170 of the chamber 162. As another example, the protective gas flow can be parallel to the surface to be protected, or have a flow component that is parallel to the surface to be protected (for example, in a region near the secondary focus SF). As another example, a gas flow (referred to as a dynamic airlock) can be used to prevent material from leaving the EUV radiation source 160 in the region of the secondary focus SF. The dynamic airlock can generate a gas flow from the region of the secondary focus SF toward the irradiation site 165. In general, a stable guided flow 171 flowing out of the collector 168 can be formed by a combination of one or more of these flows. The directed flow 171 helps contain and carry away from the collector 168 the debris, including vapor, ions, and micro- and nano-particles, generated from the target 164 during the generation of the plasma 167. Other flows may be formed. Figure 1A The intermediate guide flow 171 is depicted as having only two paths, but it is understood that it may extend along multiple paths. The airflow may extend along various other paths or regions away from the collector 168 and toward the discharge opening 120 .

[0055] The interior 161 is at a low pressure, and the pressure differential at the discharge opening 120 is not large. However, by vacuuming the discharge opening 120 (by means of the exhaust pump 108 in fluid communication with the discharge opening 120), a small pressure differential is created at the discharge opening 120. A steady directed flow 171 of debris entrained and contained in the flow 171 is thereby directed into the discharge opening 120 and out of the interior 161, thereby significantly reducing the number of debris contact surfaces within the interior 161. Depending on the position of the chamber 162, the debris is optionally directed through the chamber passage 121, through the fluid ports 116 of the port liner 115, into the discharge opening 120, and then into the linear array 105 of fins 106. The debris is captured within the fins 106.

[0056] Because the array 105 of fins 106 is located outside the chamber 162, the array 105 can be made in a linear form (as opposed to a radial form that can be used when installed in the interior 161 of the chamber 162). In this way, the design of the array 105 is simplified, which results in simplicity and efficiency in manufacturing and installation. In addition, because it is outside the chamber 162, the debris disposal device 100 can be replaced without having to open the chamber 162. In addition, because the debris disposal device 100 is outside the chamber 162, the upstream side 117u of the fluid port 116 and the array 105 of fins 106 are not in the line of sight of the primary focus PF or the secondary focus SF, as described above. Therefore, EUV light 163 is less likely to interact with the debris disposal device 100, and specifically, less likely to interact with the fins 106. Therefore, when compared to fins placed inside the interior 161 (and in direct line of sight of the primary focus PF and the secondary focus SF), advantageously, stray light generated by reflection of EUV light 163 or even light beam 166 from the surface of the fin 106 is significantly reduced. Therefore, EUV light 163 is more efficiently generated and more efficiently transmitted to the secondary focus SF for use by a lithography exposure apparatus that receives the EUV light 163 when the debris handling apparatus 100 is used.

[0057] The debris disposal device 100 may also include a heater 141 configured to maintain the temperature of the fins 106 above the melting point of the material of the debris to prevent the debris from becoming trapped within the fins 106 and adhering to the fins 106. In addition, the debris disposal device 100 includes a drain 130 configured to discharge any debris collected in the fins 106 of the array 105 from the array 105. The drain 130 relies on gravity to remove debris from the array 105. In addition, the drain 130 is configured to function independently of the relative gravitational position between the drain opening 120 and the fluid port 116. Thus, for example, the drain 130 is configured to function if the drain opening 120 is positioned below the fluid port 116 of the port liner 115 under the action of gravity (e.g., as shown in FIG. 1 ). Figure 1AAs shown, if gravity is along the -X direction, Figure 7 ), and the drain device is also configured to function if the drain opening is positioned above the fluid port 116 of the port liner 115 under the action of gravity (as shown in FIG. Figure 6 In addition, depending on the relative gravitational position between the discharge opening 120 and the fluid port 116, the discharge device 130 can be formed by specific features of the array liner 109 and / or the fluid port 116 (such as Figure 7 ). Drain 130 is able to function independent of the relative gravitational position between drain opening 120 and fluid port 116 because array 105 of fins 106 has been moved outside chamber 162 and fluid port 116 remains in fluid communication with interior 161 via drain opening 120.

[0058] Next, details of the debris handling device 100 will be discussed with reference to various implementations.

[0059] refer to Figure 2 , the implementation device 200 of the debris handling device 100 shown is mounted to the wall 170 of the chamber 162 (of the EUV radiation source 260) by means of the channel structure 222, and the design of the radiation source 260 is similar to that of the radiation source 160. In the debris handling device 200, the linear array 105 of fins 106 is designed as an array 205 of fins 206, and the fins 206 have a v-shaped cross-section (and are referred to as "v-shaped fins" in the following) 206 taken along a plane including the flow direction F and a direction perpendicular to the flow direction F. As described below, in Figure 3C and Figure 3D 206. The design of the v-shaped fins 206 is more clearly shown in FIG. 205. The array 205 of v-shaped fins 206 is arranged in the cavity 209c of the array liner 209 and is mounted to the array liner 209. The debris disposal device 200 also includes a port liner 215 that defines a fluid opening or port 216, and as described above, the port liner 215 and the array liner 209 are sealed to each other. Exhaust material and debris from the interior 161 of the chamber 162 are drawn in through the discharge opening 220 of the wall 170 of the chamber 162, through the chamber channel 221 within the channel structure 222, and through the upstream side 217u of the fluid port 216. The exhaust material and debris pass through the fluid port 216, through the downstream side 217d of the fluid port 216, and then through the array 205 of v-shaped fins 206.

[0060] For details of the array pad 209, array 205, port pad 215 and fluid port 216, refer to Figures 3A-3E Discuss. Figures 4A-4C An example of a fin 406 is shown, Figures 5A-5C An example of a pair of fins 506 - 8 , 506 - 9 (within an array of multiple fins) is shown.

[0061] like Figure 2 and Figures 3A-3E As shown, the array gasket 209 surrounds the array 205 of v-shaped fins 206. Specifically, each fin 206 is mounted to the gasket 209, as described below. In addition, the array gasket 209 is connected to the port gasket 215 at the interface 210 to form an airtight seal. For example, the array gasket 209 and the port gasket 215 can include flanges connected at the interface 210, and a gasket or O-ring can be fixed between the flanges to provide an airtight seal.

[0062] The array liner 209 may be made of a material different from the material of the v-fin 206. The array liner 209, the v-fin 206, and the port liner 215 are made of materials that do not react with the material and debris to be captured by the debris disposal device 200. Thus, in the above example, if the target 164 includes tin, the debris may include tin, and the array liner 209, the v-fin 206, and the port liner 215 are made of materials that do not react with the tin. In some implementations, the array liner 209 and the port liner 215 are made of stainless steel. The v-fin 206 may be made of a refractory metal or metal alloy. For example, the v-fin 206 may be made of molybdenum.

[0063] The v-shaped fins 206 are arranged relative to each other so that v-shaped grooves 324 are formed between adjacent pairs of fins in the array 205, as shown in FIG. Figure 3C and Figure 3D The V-shape of the fin 206 and the groove 324 are also Figure 3C and Figure 3D The coordinate system of the array 205 is given by Xf, Yf, Zf, where Xf is along the flow direction F. Figure 3C and Figure 3D As shown, the V-shape of the fin refers to the shape of the fin taken in the XfYf plane. Figures 3A-3E In the example of FIG. 2 , the fins 206 include 18 v-shaped fins 306 - 1 , 306 - 2 , . . . 306 - 18 . However, the array 205 may include fewer than 18 fins or more than 18 fins. Figure 3D The groove 324 shown in the figure is the groove 324-8 / 9 between the fins 306-8 and 306-9. Each v-shaped groove 324 includes an input groove channel and an output groove channel. Figure 3DIn the example of , the groove 324-8 / 9 includes an input groove channel 307i-8 / 9 and an output groove channel 307o-8 / 9. Each input groove channel 307i-8 / 9 faces the interior 161 of the chamber 162, which means that the input groove channel 307i-8 / 9 is located on the side of the array 205 that is fluidly connected to the interior 161 of the chamber 162 (by means of the fluid port 116, the chamber channel 221 and the exhaust opening 220). Each output groove channel 307o-8 / 9 faces an exhaust pump, such as the exhaust pump 108 of the debris disposal device 100 of Figure 1. This means that the output groove channel 307 is located at the side of the array 205 that is fluidly connected to the exhaust pump 108. The flow direction F of the debris is defined as from the input groove channel 307i-8 / 9 to the output groove channel 307o-8 / 9. The input groove channels 307i-8 / 9 and the output groove channels 307o-8 / 9 are flat surfaces, where the planes are positioned perpendicular to the flow direction F.

[0064] like Figures 4A-4C As shown, each v-shaped fin 406 includes a first segment 426s1 and a second segment 426s2, which are arranged relative to each other at an obtuse angle Φ, thereby forming the v-shape of the fin 406. For reference, a coordinate system Xf, Yf, Zf local to the fin 406 is shown. The axis Xf is aligned with the flow direction F. The fins 406 are arranged relative to each other along the Yf axis. In particular, with reference to this local coordinate system, the first segment 426s1 and the second segment 426s2 are angled relative to each other about an inflection line IL parallel to the Zf axis. This arrangement gives the fin 406 a v-shape, as shown in FIG. Figure 4C As shown more clearly in . The bending radius BR between the first segment 426s1 and the second segment 426s2 can be greater than 1 millimeter (mm), for example 3 mm. In particular, due to this v-shape, an angle θ1 is formed between the first segment 426s1 and the flow direction F, and an angle θ2 is formed between the second segment 426s2 and the flow direction F. In some implementations, the angle θ1 is equal to the angle θ2, while in other implementations, the angle θ1 is different from the angle θ2. For example, each angle θ1, θ2 can be a value greater than 0° and less than 20°. As another example, each angle θ1, θ2 can be a value greater than 5° and less than 15°. In some implementations, each angle θ1, θ2 is a value in the range of 10° to 13°. In some implementations, each v-shaped fin 406 has a thickness T (between 1 millimeter and 3 millimeters (mm)). Figure 4C In some implementations, the length L of each v-shaped fin 406 is Figure 4B and Figure 4C ) (along the flow direction F) is at least 50 mm, at least 75 mm, at least 100 mm or at least 120 mm.

[0065] like Figure 5A and Figure 5C As shown, the distance D between each adjacent fin can be advantageously in the range of 9 mm to 20 mm. Figure 5A and Figure 5C In the example of FIG. 5 , distance D is shown as the distance between fins 506-8 and 506-9. Thus, because fin 506-8 includes segments 526s1-8 and 526s2-8, and fin 506-9 includes segments 526s1-9 and 526s2-9 (also in FIG. 5 ), distance D is shown as the distance between fins 506-8 and 506-9. Figure 5E ), so the distance D is given by the distance D between segments 526s1-8 and 526s1-9 and the distance D between segments 526s2-8 and 526s2-9 ( Figure 5C ).

[0066] Reference again Figures 4A-4C , each v-shaped fin 406 is made of a first sub-fin 427f1 and a second sub-fin 427f2, which are stacked on each other along the Zf direction. The first sub-fin 427f1 includes two upper portions of two segments 426s1 and 426s2, and the second sub-fin 427f2 includes two lower portions of two segments 426s1 and 426s2. The interface 428 between the first sub-fin 427f1 and the second sub-fin 427f2 is linearly oriented at an angle relative to the flow direction F. The interface 428 is a gap or space between the first sub-fin 427f1 and the second sub-fin 427f2. By dividing each fin 406 into sub-fins 427f1, 427f2, the installation of the array 405 can be simplified, and deformation and high stress due to thermal expansion can be reduced. In addition, the interface 428 facilitates the manipulation of debris along the flow direction F toward the exhaust pump 108. From Figure 4B As can be more clearly seen in FIG. 4 , the gap at interface 428 extends in a direction (or directions) that is not parallel to the Xf direction; that is, the direction in which the gap at interface 428 extends is not parallel to the Xf direction. Instead, the direction in which the gap at interface 428 extends is inclined at a certain angle relative to the Xf direction. Because interface 428 extends at an oblique angle relative to the Xf direction, any debris within a particular groove remains entrained within the groove as it passes through the groove and is less likely to pass through interface 428 and enter another adjacent groove.

[0067] In addition, in order to facilitate the installation of the v-shaped fin 406 on the array pad 209, each v-shaped fin 406 includes a first extension 429e1 and a second extension 429e2, the first extension 429e1 is defined at the end of the first sub-fin 427f1 farthest from the interface 428, and the second extension 429e2 is defined at the end of the second sub-fin 427f2 farthest from the interface 428. The first extension 429e1 can be formed by the curved edge of the first sub-fin 427f1, and the second extension 429e2 can be formed by the curved edge of the second sub-fin 427f2. When correctly installed, these first extensions 429e1 and second extensions 429e2 can be flush with the corresponding inner walls of the array pad 209. The first extension 429e1 and the second extension 429e2 can extend from the corresponding first sub-fin 427f1 and the second sub-fin 426f2 along the XfYf plane.

[0068] The first sub-fin 427f1 of each v-shaped fin 406 is mounted to the first upper wall 309w1 of the array pad 209 at the first connection interface 430I1 by means of the first extension 429e1. ​​And the second sub-fin 427f2 of each v-shaped fin 406 is mounted to the second lower wall 309w2 of the array pad 209 at the second connection interface 430I2 by means of the second extension 429e2. Figure 3E is shown in Figure 4B Each connection interface 430I1, 430I2 may include a corresponding plurality of sub-connection interfaces 432I1_j, 432I2_j, where j is a set of integers. Figure 4B In the example, connection interface 430I1 includes sub-connection interfaces 432I1_1, 432I1_2, 432I1_3, 432I1_4, and connection interface 430I2 includes sub-connection interfaces 432I2_1, 432I2_2, 432I2_3, 432I2_4. In other implementations, each connection interface 430I1, 430I2 may include less than four or more than four sub-connection interfaces.

[0069] like Figures 4A-4C As shown, each v-shaped fin 406 includes a concave bevel 435 at the input groove channel of the adjacent v-shaped groove. The input groove channel of the adjacent v-shaped groove is positioned along the -Xf direction relative to the output groove channel of the adjacent v-shaped groove because the flow direction F is aligned with the +Xf direction. The concave bevel 435 is formed with two bevels in the second section 426s2 so that the notch on each fin faces the fluid port 216 ( Figure 2 , Figure 3A and Figure 3B). Specifically, the concave bevel 435 is the result of the absence of material from a portion of the first sub-fin 427f1 in the second section 426s2 and a portion of the second sub-fin 427f2 in the second section 426s2 near the interface 428 location. The concave bevel 435 is formed for the following reasons. Specifically, the temperature of the debris flow approaching the fin array 406 is much lower than the melting temperature of the debris material and the target material, and as described above, the fins 406 are maintained at a temperature above the melting point of the debris material. This low temperature flow will cool the leading edge of the fin (the edge facing the fluid port 216) and make it difficult to achieve the melting temperature of the debris and / or target material at the fin array 406 with reasonable heater power. By introducing the concave bevel edge 435, and thereby removing the leading edge portion that is most exposed to the cold flow, the temperature of the fin 406 is maintained above the melting temperature of the debris and / or target material even as these lower temperature flows approach the fin 406. On the other side of the fin 406, as shown in FIG. Figures 4A-4C In some implementations shown, a convex bevel 437 can be formed at the output trench channel of an adjacent trench.

[0070] In other implementations, such as Figures 5A-5E As shown, adjacent pairs of v-shaped fins in array 205 are mounted together at the same connection interface in array pad 209. Figures 5A-5E In the example of FIG. 1 , a pair of v-shaped fins 506-8 and 506-9 are shown mounted together. Obviously, the v-shaped fins 506-8 and 506-9 are offset from each other along the Yf axis. Each v-shaped fin 506-8 and 506-9 is made of a corresponding first sub-fin 527f1-8, 527f1-9 and a corresponding second sub-fin 527f2-8, 527f2-9 stacked relative to each other along the Zf direction (see FIG. 1 ). Figure 5E). The first sub-fins 527f1-8 and 527f1-9 include two sections 526s1-8 and 526s2-8, and two upper parts of 526s1-9 and 526s2-9, respectively. And, the second sub-fins 527f2-8 and 527f2-9 include two sections 526s1-8 and 526s2-8, and two lower parts of 526s1-9 and 526s2-9, respectively. An interface 528-8 (which may be a gap or space) is formed between the first sub-fin 527f1-8 and the second sub-fin 527f2-8, and an interface 528-9 (which may be a gap or space) is formed between the first sub-fin 527f1-9 and the second sub-fin 527f2-9. These interfaces 528-8 and 528-9 are similar to the interface 428 and thus are each oriented linearly at an angle relative to the flow direction F to facilitate manipulation of debris along the flow direction F toward the exhaust pump 108. In addition, each v-shaped fin 506-8 and 506-9 includes a concave bevel 535-8 and 535-9 at the input groove channel of the adjacent v-shaped groove, and the concave bevel 535-8 and 535-9 function similarly to the concave bevel 435 described above.

[0071] V-shaped fins 506-8 and 506-9 are paired and mounted together on array pad 209 at connection interfaces 530I1 and 530I2 ( Figure 5B and 5D ). Other fins within the array 205 can be installed similarly to fins 506-8 and 506-9. For example, the connection interface 530I1 may include a plurality of sub-connection interfaces 532I1_j, where j is a set of integers 1, 2, 3, 4, and the connection interface 530I2 may include a plurality of sub-connection interfaces 532I2_j, where j is a set of integers 1, 2, 3, 4. In order to facilitate the pairing of adjacent v-shaped fins 506-8 and 506-9 for installation, the v-shaped fin 506-8 includes a first extension 529e1-8 at the first connection interface 530I1, and the v-shaped fin 506-9 includes a first extension 529e1-9 at the first connection interface 530I1. The v-shaped fin 506-8 also includes a second extension 529e2-8 at the second connection interface 530I2, and the v-shaped fin 506-9 includes a second extension 529e2-9 at the second connection interface 530I2. To assemble the v-shaped fins 506-8 and 506-9 into the array pad 209, the first extensions 529e1-8 and 529e1-9 are stacked or nested together, and the second extensions 529e2-8 and 529e2-9 are stacked or nested together. Figure 5A and 5B. Once these extensions are stacked, they can be fixed together and can also be fixed to the array pad 209 using a connecting mechanism. The connecting mechanism is detachable, which means that after the extensions are fixed together and fixed to the array pad 209, they can be disconnected later without damaging the assembly. In this particular example, the first connection interface 530I1 includes sub-connection interfaces 532I1_1, 532I1_2, 532I1_3, 532I1_4, and the second connection interface 530I2 includes sub-connection interfaces 532I2_1, 532I2_2, 532I2_3, 532I2_4. Each sub-connection interface includes a connecting mechanism that connects or fixes the extension to the array pad 209.

[0072] The implementation of the connection mechanism at the sub-connection interface 532I1_3 is as follows Figure 5D As shown, it is noted that in this implementation, other connecting mechanisms are designed in the same manner. Figure 5D As shown, the connection mechanism at the sub-connection interface 532I1_3 includes a bolt 531 passing through an opening in the first upper wall 309w1 of the array pad 209 and an opening in the first extension 529e1-8, 529e1-9 of the corresponding V-shaped fins 506-8, 506-9. Figure 5E , the openings in the first extensions 529e1-8, 529e1-9 at the sub-connection interface 532I1_3 are labeled 536-8 and 536-9, respectively. The connection mechanism at the sub-connection interface 532I1_3 also includes a nut 533 and a spring washer 534. The spring washer 534 can be configured to compensate for any mismatch in thermal expansion between the wall 309w1, the first extension 529e1-9 and the first extension 529e1-8, but still provide the required clamping force between the fins 506-8, 506-9 and the wall 309w1.

[0073] refer to Figure 6 In some implementations, a debris handling device 600 (similar in design to the debris handling device 100) is arranged relative to an EUV radiation source 660, wherein an exhaust opening 620 is positioned above a fluid port 616 of a port liner 615 under the force of gravity. The direction of gravity is indicated by arrow G. In these implementations, the exhaust device includes an exhaust port 642 in fluid communication with an output groove channel 607o of the grooves 607 of the linear array 605 of fins 606. The exhaust path is indicated by arrow 640. For comparison, the path for removing debris from an interior 661 of a chamber (or container) 662 is depicted by arrow 671.

[0074] refer to Figure 7In some implementations, a debris disposal device 700 (designed similarly to the debris disposal devices 100 or 200) is arranged relative to an EUV radiation source 760, wherein an exhaust opening 720 is positioned under the fluid port 716 of a port liner 715 under the force of gravity. The direction of gravity is indicated by arrow G. In these implementations, the exhaust device includes the fluid port 716 of the port liner 715 and at least a portion of the external chamber channel 721. The exhaust continues to the external chamber channel 721 through an opening 744 in the channel structure 722. The exhaust path is indicated by arrow 740. On the other hand, the path for removing debris from the interior 761 of the chamber (or container) 762 is depicted by arrow 771.

[0075] Referring again to FIG. 1 , the debris handling device 100 may further include a heater 141 configured to maintain the temperature of the fins 106 above the melting point of the debris and / or target material. Figure 8 , an implementation 841 of a heater is shown. The heater 841 is in thermal contact with the array pad 209 and the port pad 215. In other implementations, the heater 841 is in thermal contact only with the array pad 209. The heater 841 can be formed by any suitable heating element, such as a resistive wire, whose shape fits into the grooves on the outer surface of the array pad 209 (and / or the port pad 215). The array pad 209 and the port pad 215 can be formed by metal sheets that are bent and then welded together, brazed, and optionally coated with titanium nitride (e.g., by chemical vapor deposition).

[0076] The implementation may be further described using the following terms.

[0077] 1. A debris handling device for controlling debris within a controlled environment chamber of an extreme ultraviolet (EUV) radiation source, the debris handling device comprising:

[0078] an array of v-shaped fins, wherein the fins are arranged relative to each other such that v-shaped grooves are formed between pairs of adjacent fins of the array, each v-shaped fin comprising two segments arranged at an obtuse angle to each other, and each v-shaped groove comprising an input groove channel facing the interior of the chamber and an output groove channel facing the exhaust pump, such that a flow direction is defined from the input groove channel to the output groove channel;

[0079] The angle between each segment and the flow direction is less than 20°.

[0080] 2. A debris disposal device according to clause 1, wherein the thickness of each v-shaped fin is in the range of 1 mm to 3 mm.

[0081] 3. A debris disposal device according to claim 1, wherein the distance between each adjacent fin is in the range of 9 millimeters to 20 millimeters (mm), and the length of each v-shaped fin along the flow direction is at least 50 mm, at least 75 mm, at least 100 mm or at least 120 mm.

[0082] 4. The debris disposal device according to clause 1, wherein each v-shaped fin is made of a first sub-fin and a second sub-fin.

[0083] 5. The debris disposal device according to clause 4, wherein an interface between the first sub-fin and the second sub-fin comprises a portion that is linearly oriented at an angle relative to the flow direction.

[0084] 6. The debris disposal device of clause 4, further comprising a liner in which the v-shaped fin array is mounted.

[0085] 7. The debris disposal device according to clause 6, wherein the first sub-fin is mounted to a first wall of the liner and the second sub-fin is mounted to a second wall of the liner.

[0086] 8. The debris disposal device of clause 6, wherein the liner comprises a material different from the material of the v-shaped fins.

[0087] 9. The debris disposal device of clause 6, wherein the liner is made of stainless steel and the v-fins are made of molybdenum.

[0088] 10. The debris disposal device of clause 6, wherein adjacent pairs of v-shaped fins are mounted together to the liner at the same connection interface.

[0089] 11. The debris disposal device of clause 6, wherein the v-shaped fins are each mounted to the gasket at a plurality of connection interfaces, wherein each connection interface comprises a bolt, a nut and a spring washer passing through the gasket and the v-shaped fin.

[0090] 12. The debris disposal device of clause 1, wherein each v-shaped fin comprises a concave beveled edge at the input groove channel of an adjacent v-shaped groove.

[0091] 13. The debris disposal device of clause 1, further comprising a drain device in fluid communication with the v-shaped groove, the drain device being configured to remove debris collected by the v-shaped fin array.

[0092] 14. The debris disposal device of clause 1, wherein each v-shaped fin comprises a refractory metal or metal alloy.

[0093] 15. A debris disposal device according to clause 1, wherein the angle between each segment and the flow direction is greater than 0° and less than 20°; greater than 5° and less than 15°; or greater than 10° and less than 13°.

[0094] 16. A debris handling apparatus for controlling debris in a controlled environment interior of a chamber of an extreme ultraviolet (EUV) radiation source, wherein generated EUV light is transmitted along an optical axis within the chamber interior, the debris handling apparatus comprising:

[0095] a linear array of fins, the fins being arranged relative to each other such that grooves are formed between adjacent fins of the array, each groove comprising an output groove channel and an input groove channel facing the exhaust pump such that a flow direction is defined from the input groove channel to the output groove channel; and

[0096] The port liner defines a fluid port including an upstream side located outside the chamber and in fluid communication with the interior of the chamber, and a downstream side adjacent to and in fluid communication with the input trench channel.

[0097] 17. A debris disposal device according to clause 16, wherein the flow direction of all of the channels is the same.

[0098] 18. A debris disposal device according to clause 16, wherein the upstream side of the port liner is in fluid communication with a discharge opening in a wall of the chamber by means of a chamber channel external to the chamber.

[0099] 19. A debris disposal device according to clause 18, wherein the chamber passage has an annular shape and extends around an outer circumference outside the chamber.

[0100] 20. The debris disposal device of clause 18, wherein the upstream side of the port liner is positioned at an angle of at least 90° to the discharge opening with respect to the outer circumference outside the chamber.

[0101] 21. The debris disposal device of clause 16, further comprising a discharge device configured to discharge debris collected in the linear fin array from the linear fin array.

[0102] 22. A debris disposal device according to clause 21, wherein:

[0103] the upstream side of the port liner being in fluid communication with a drain opening in a wall of the chamber by means of a chamber passage outside the chamber, and the drain opening being positioned under gravity below the fluid port of the port liner, and the drain means comprising the fluid port of the port liner and at least a portion of the chamber passage; or

[0104] The drain opening is gravity positioned above the fluid port of the port liner, and the drain device includes a drain port in fluid communication with the output groove channel.

[0105] 23. The debris disposal apparatus of clause 16, wherein the EUV light is transmitted within the chamber interior along the optical axis from a primary focus to a secondary focus, and neither the primary focus nor the secondary focus is in line of sight of the upstream side of the fluid port.

[0106] 24. The debris disposal device of clause 16, wherein each fin is a v-shaped fin comprising two segments arranged at an obtuse angle to each other, and each groove is a v-shaped groove.

[0107] 25. The debris disposal device according to clause 24, wherein each v-shaped fin is made of a first sub-fin and a second sub-fin.

[0108] 26. The debris disposal device according to clause 16, further comprising an array gasket, the fin array being mounted in the array gasket, the array gasket and the port gasket being sealingly connected.

[0109] 27. The debris disposal device according to clause 16, wherein each fin comprises a first sub-fin and a second sub-fin separated from each other.

[0110] 28. The debris disposal device according to clause 27 further comprises an array pad in which the fin array is mounted, wherein the first sub-fin is mounted to the first wall of the array pad by means of a detachable connector, and the second sub-fin is mounted to the second wall of the array pad by means of a detachable connector.

[0111] 29. The debris disposal device according to clause 27, wherein a gap between the first sub-fin and the second sub-fin extends in a direction that is not parallel to an edge of the first sub-fin mounted to the first wall.

[0112] 30. The debris disposal device of clause 29, wherein the extent of the gap along a direction perpendicular to the flow direction is generally constant throughout the gap.

[0113] 31. The debris disposal device of clause 16, wherein each fin comprises a concave beveled edge at the input groove channel of an adjacent groove.

[0114] 32. The debris disposal device of clause 31, wherein the concave bevel is formed with two bevels defining a notch facing the fluid port.

[0115] 33. A debris disposal device according to clause 31, wherein each fin comprises a convexly beveled edge at the output groove channel of an adjacent groove.

[0116] 34. The debris disposal apparatus of clause 16, further comprising a heater configured to maintain a temperature of the fin above a melting point of the debris generated during generation of the EUV light.

[0117] 35. The debris disposal device of clause 34, further comprising an array liner in which the fin array is mounted, wherein the heater is in thermal contact with the array liner and the port liner.

[0118] 36. The debris disposal device of clause 16, wherein each fin comprises a refractory metal or metal alloy.

[0119] 37. An extreme ultraviolet (EUV) radiation source container, comprising:

[0120] a chamber comprising one or more walls defining a chamber interior, wherein a primary focus at which plasma is generated by light pulses interacting with a target and a secondary focus at which EUV radiation generated by the plasma is focused are within the chamber interior, and in use, EUV light is transmitted along an optical axis from the primary focus to the secondary focus;

[0121] a control system configured to maintain the chamber and a temperature inside the chamber below a melting point of a material of the target and to flow a purge gas away from the primary focus;

[0122] a debris disposal device including a fluid port located outside the chamber and including an upstream side in fluid communication with the interior of the chamber and a downstream side in fluid communication with a debris capture array; and

[0123] A discharge opening is in fluid communication with the chamber interior at a first end and in fluid communication with the upstream side of the fluid port at a second end.

[0124] 38. An EUV radiation source container according to clause 37, wherein the control system is configured to maintain a temperature of at least a portion of the debris handling device above a melting point of the material of the target and of the material of the debris generated within the chamber.

[0125] 39. A method of processing debris generated within a controlled environment of a chamber of an extreme ultraviolet (EUV) radiation source, the method comprising:

[0126] passing a gas flow through a discharge opening in a wall of the chamber, including directing the gas flow from inside the chamber through the discharge opening to outside the chamber;

[0127] directing the airflow from the discharge opening to a debris disposal device outside the chamber;

[0128] collecting debris within the airflow at the debris disposal device; and

[0129] The debris collected by the debris disposal device is discharged through a discharge device.

[0130] 40. The method of clause 39, wherein directing the airflow from the chamber interior through the discharge opening comprises directing the airflow from a collector in the chamber interior to the discharge opening.

[0131] 41. The method of clause 39, wherein directing the airflow from the discharge opening to the debris disposal device outside the chamber comprises passing the airflow around at least a portion of the outer circumference of the chamber through a chamber passage located outside the upstream side of a fluid port of the debris disposal device.

[0132] 42. A method according to clause 39, wherein collecting debris within the airflow at the debris disposal device includes passing the debris through an input groove channel of a plurality of grooves, the plurality of grooves being formed between pairs of adjacent fins in a linear fin array, and collecting debris within at least some of the grooves.

[0133] 43. The method of clause 42, wherein discharging the debris collected by the debris disposal device comprises manipulating the debris flow through each respective groove and entraining the debris within the respective groove.

[0134] 44. A method according to claim 42, wherein discharging the debris collected by the debris disposal device includes passing the collected debris along a discharge path that overlaps with a gas path guiding the airflow, or discharging the debris collected by the debris disposal device includes passing the collected debris along a discharge path that is separate from the gas path guiding the airflow.

[0135] 45. The method of clause 39, further comprising compensating for thermal expansion mismatch between a gasket in which the fin is mounted and the fin.

[0136] 46. ​​The method of clause 39, wherein directing the airflow from the discharge opening to the debris disposal device outside the chamber comprises directing the airflow along a single path to the debris disposal device.

[0137] 47. A debris handling apparatus for controlling debris within a controlled environment chamber of an extreme ultraviolet (EUV) radiation source, the debris handling apparatus comprising:

[0138] an array of v-shaped fins arranged relative to each other such that v-shaped grooves are formed between adjacent fins of the array,

[0139] in:

[0140] Each v-shaped fin comprises two segments arranged at an obtuse angle to each other, and each v-shaped groove comprises an input groove channel facing the interior of the chamber and an output groove channel facing the exhaust pump, so that the flow direction is defined from the input groove channel to the output groove channel; and

[0141] Each v-shaped fin includes a concave beveled edge at the input groove channel of an adjacent v-shaped groove.

[0142] 48. A debris disposal device according to clause 47, wherein the concave bevel is formed with two bevels defining a recess facing the interior of the chamber.

[0143] 49. The debris disposal device of clause 47, wherein each v-shaped fin comprises a convex beveled edge at the output groove channel of an adjacent v-shaped groove.

[0144] 50. The debris disposal device of clause 47, further comprising a heater configured to maintain a temperature of the v-fin above a melting point of the material in the debris.

[0145] 51. The debris disposal device of clause 50, further comprising a liner in which the v-shaped fin array is mounted, wherein the heater is in thermal contact with the liner.

[0146] The implementations described above and other implementations are within the scope of the following claims.

Claims

1. A debris handling device for controlling debris within a controlled environment chamber of an extreme ultraviolet (EUV) radiation source, the debris handling device comprising: an array of v-shaped fins, wherein the fins are arranged relative to each other such that v-shaped grooves are formed between pairs of adjacent fins of the array, each v-shaped fin comprising two segments arranged at an obtuse angle to each other, and each v-shaped groove comprising an input groove channel facing the interior of the chamber and an output groove channel facing the exhaust pump, such that a flow direction is defined from the input groove channel to the output groove channel; The angle between each segment and the flow direction is less than 20°.

2. The debris disposal device according to claim 1, wherein the thickness of each v-shaped fin is in the range of 1 mm to 3 mm.

3. The debris disposal device according to claim 1, wherein the distance between each adjacent fin is in the range of 9 millimeters to 20 millimeters (mm), and the length of each v-shaped fin along the flow direction is at least 50 mm, at least 75 mm, at least 100 mm or at least 120 mm.

4. The debris disposal device according to claim 1, wherein each V-shaped fin is made of a first sub-fin and a second sub-fin.

5. The debris disposal device of claim 4, wherein an interface between the first sub-fin and the second sub-fin includes a portion that is linearly oriented at an angle relative to the flow direction.

6. The debris disposal device of claim 4, further comprising a liner, the v-shaped fin array being mounted in the liner.

7. The debris disposal device of claim 6, wherein the first sub-fin is mounted to a first wall of the liner and the second sub-fin is mounted to a second wall of the liner.

8. The debris disposal device of claim 6, wherein the liner comprises a material different from the material of the v-shaped fins.

9. The debris disposal device of claim 6, wherein the liner is made of stainless steel and the v-fins are made of molybdenum.

10. The debris disposal device of claim 6, wherein adjacent pairs of v-shaped fins are mounted together to the liner at the same connection interface.

11. The debris disposal device of claim 6, wherein the v-shaped fins are each mounted to the gasket at a plurality of connection interfaces, wherein each connection interface includes a bolt, a nut, and a spring washer passing through the gasket and the v-shaped fin.

12. The debris disposal device of claim 1, wherein each v-shaped fin includes a concave beveled edge at the input groove channel of an adjacent v-shaped groove.

13. The debris disposal device of claim 1, further comprising a drain device in fluid communication with the v-shaped groove, the drain device being configured to remove debris collected by the v-shaped fin array.

14. The debris disposal device of claim 1, wherein each v-shaped fin comprises a refractory metal or metal alloy.

15. The debris disposal device of claim 1, wherein the angle between each segment and the flow direction is greater than 0° and less than 20°; greater than 5° and less than 15°; or greater than 10° and less than 13°.

16. A debris handling apparatus for controlling debris in a controlled environment interior of a chamber of an extreme ultraviolet (EUV) radiation source, wherein generated EUV light is transmitted along an optical axis within the chamber interior, the debris handling apparatus comprising: a linear array of fins, the fins being arranged relative to each other such that grooves are formed between adjacent fins of the array, each groove comprising an output groove channel and an input groove channel facing the exhaust pump such that a flow direction is defined from the input groove channel to the output groove channel; as well as The port liner defines a fluid port including an upstream side located outside the chamber and in fluid communication with the interior of the chamber, and a downstream side adjacent to and in fluid communication with the input trench channel.

17. The debris disposal device of claim 16, wherein the flow direction of all of the channels is the same.

18. The debris disposal device of claim 16, wherein the upstream side of the port liner is in fluid communication with a discharge opening in a wall of the chamber by means of a chamber passage external to the chamber.

19. The debris disposal device of claim 18, wherein the chamber passage has an annular shape and extends around an outer circumference outside the chamber.

20. The debris disposal device of claim 18, wherein the upstream side of the port liner is positioned at an angle of at least 90° to the discharge opening with respect to the outer circumference outside the chamber.

21. The debris disposal device of claim 16, further comprising a discharge device configured to discharge debris collected in the linear fin array from the linear fin array.

22. The debris disposal device of claim 21, wherein: the upstream side of the port liner being in fluid communication with a drain opening in a wall of the chamber by means of a chamber passage outside the chamber, and the drain opening being positioned under gravity below the fluid port of the port liner, and the drain means comprising the fluid port of the port liner and at least a portion of the chamber passage; or The drain opening is gravity positioned above the fluid port of the port liner, and the drain device includes a drain port in fluid communication with the output groove channel.

23. The debris disposal device of claim 16, wherein the EUV light is transmitted from a primary focus to a secondary focus within the chamber interior along the optical axis, and neither the primary focus nor the secondary focus is in the line of sight of the upstream side of the fluid port.

24. The debris disposal device of claim 16, wherein each fin is a v-shaped fin comprising two segments arranged at an obtuse angle to each other, and each groove is a v-shaped groove.

25. The debris disposal device of claim 24, wherein each V-shaped fin is made of a first sub-fin and a second sub-fin.

26. The debris disposal device according to claim 16, further comprising an array gasket, the fin array being mounted in the array gasket, the array gasket and the port gasket being sealingly connected.

27. The debris disposal device according to claim 16, wherein each fin comprises a first sub-fin and a second sub-fin separated from each other.

28. The debris disposal device according to claim 27 further includes an array pad in which the fin array is installed, wherein the first sub-fin is mounted to the first wall of the array pad by means of a detachable connector, and the second sub-fin is mounted to the second wall of the array pad by means of a detachable connector.

29. The debris disposal device according to claim 27, wherein a gap between the first sub-fin and the second sub-fin extends in a direction that is not parallel to an edge of the first sub-fin mounted to the first wall.

30. The debris disposal device of claim 29, wherein the extent of the gap along a direction perpendicular to the flow direction is generally constant throughout the gap.

31. The debris disposal device of claim 16, wherein each fin includes a concave beveled edge at the input channel of an adjacent one of the channels.

32. The debris disposal device of claim 31, wherein the concave bevel is formed with two bevels defining a notch facing the fluid port.

33. The debris disposal device of claim 31 wherein each fin includes a convexly beveled edge at the output channel of an adjacent channel.

34. The debris handling apparatus of claim 16, further comprising a heater configured to maintain a temperature of the fin above a melting point of the debris generated during generation of the EUV light.

35. The debris disposal device of claim 34, further comprising an array liner in which the fin array is mounted, wherein the heater is in thermal contact with the array liner and the port liner.

36. The debris disposal device of claim 16, wherein each fin comprises a refractory metal or metal alloy.

37. An extreme ultraviolet (EUV) radiation source container, comprising: a chamber comprising one or more walls defining a chamber interior, wherein a primary focus at which plasma is generated by light pulses interacting with a target and a secondary focus at which EUV radiation generated by the plasma is focused are within the chamber interior, and in use, EUV light is transmitted along an optical axis from the primary focus to the secondary focus; a control system configured to maintain the temperature of the chamber and the interior of the chamber below a melting point of a material of the target and to flow a purge gas away from the primary focus; a debris disposal device including a fluid port located outside the chamber and including an upstream side in fluid communication with the interior of the chamber and a downstream side in fluid communication with a debris capture array; as well as A discharge opening is in fluid communication with the chamber interior at a first end and in fluid communication with the upstream side of the fluid port at a second end.

38. The EUV radiation source container of Claim 37, wherein the control system is configured to maintain a temperature of at least a portion of the debris handling device above a melting point of the material of the target and of the material of the debris generated within the chamber.

39. A method of processing debris generated within a controlled environment of a chamber of an extreme ultraviolet (EUV) radiation source, the method comprising: passing a gas flow through a discharge opening in a wall of the chamber, including directing the gas flow from inside the chamber through the discharge opening to outside the chamber; directing the airflow from the discharge opening to a debris disposal device outside the chamber; collecting debris within the airflow at the debris disposal device; as well as The debris collected by the debris disposal device is discharged through a discharge device.

40. The method of claim 39, wherein directing the airflow from the chamber interior through the discharge opening comprises directing the airflow from a collector in the chamber interior to the discharge opening.

41. The method of claim 39, wherein directing the airflow from the exhaust opening to the debris disposal device outside the chamber comprises passing the airflow around at least a portion of an outer circumference of the chamber through a chamber passage located outside an upstream side of a fluid port of the debris disposal device.

42. The method of claim 39, wherein collecting debris within the airflow at the debris disposal device comprises passing the debris through an input groove channel of a plurality of grooves formed between pairs of adjacent fins in a linear fin array, and collecting debris within at least some of the grooves.

43. The method of claim 42, wherein discharging the debris collected by the debris disposal device comprises manipulating the debris flow through each respective groove and entraining the debris within the respective groove.

44. The method of claim 42, wherein discharging the debris collected by the debris disposal device comprises passing the collected debris along a discharge path that overlaps with a gas path that guides the gas flow, or discharging the debris collected by the debris disposal device comprises passing the collected debris along a discharge path that is separate from a gas path that guides the gas flow.

45. The method of claim 39, further comprising compensating for thermal expansion mismatch between a gasket in which the fin is mounted and the fin.

46. ​​The method of claim 39, wherein directing the airflow from the discharge opening to the debris disposal device outside the chamber comprises directing the airflow along a single path to the debris disposal device.

47. A debris handling apparatus for controlling debris within a controlled environment chamber of an extreme ultraviolet (EUV) radiation source, the debris handling apparatus comprising: an array of v-shaped fins arranged relative to each other such that v-shaped grooves are formed between adjacent fins of the array, in: Each v-shaped fin comprises two segments arranged at an obtuse angle to each other, and each v-shaped groove comprises an input groove channel facing the interior of the chamber and an output groove channel facing the exhaust pump, so that the flow direction is defined from the input groove channel to the output groove channel; and Each v-shaped fin includes a concave beveled edge at the input groove channel of an adjacent v-shaped groove.

48. The debris disposal device of claim 47, wherein the concave bevel is formed with two bevels defining a recess facing the interior of the chamber.

49. The debris disposal device of claim 47, wherein each v-shaped fin includes a convexly beveled edge at the output groove channel of an adjacent v-shaped groove.

50. The debris disposal device of claim 47, further comprising a heater configured to maintain a temperature of the v-fin above a melting point of the material in the debris.

51. The debris disposal device of claim 50, further comprising a liner in which the v-shaped fin array is mounted, wherein the heater is in thermal contact with the liner.

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