Target material reservoir for extreme ultraviolet light sources

Abstract

An apparatus for an extreme ultraviolet (EUV) light source includes a body. The body includes a first structure (246) including a first wall; and a second structure (248) including a second wall permanently joined to the first wall. An interior (203) of the body is at least partially defined by the first wall and the second wall. The first wall includes a first metallization material, and the second wall includes a second metallization material having a different thermal conductivity than the first metallization material. The interior of the body is configured to be fluidically connected to a target supply system of the EUV light source.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. application No. 62 / 949,144, filed on December 17, 2019, entitled “TARGET MATERIAL TANK FOR EXTREME ULTRAVIOLET LIGHT SOURCE,” and U.S. application No. 62 / 986,266, filed on March 6, 2020, entitled “TARGET MATERIAL TANK FOR EXTREME ULTRAVIOLET LIGHT SOURCE,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a target material reservoir for an extreme ultraviolet (EUV) light source. Background Art

[0004] EUV light can be, for example, electromagnetic radiation having a wavelength of 100 nanometers (nm) or less (sometimes also called soft x-rays), and includes, for example, light having a wavelength of 20 nm or less, between 5 nm and 20 nm, or between 13 nm and 14 nm, and can be used in photolithography processes to create extremely small features in a substrate (e.g., a silicon wafer) by initiating polymerization in a resist layer.

[0005] Methods for generating EUV light include, but are not necessarily limited to, converting a material containing an element having emission lines in the EUV range (e.g., xenon, lithium, or tin) into a plasma state. In one such method, often referred to as laser-produced plasma (LPP), the desired plasma can be generated by irradiating a target material, which is an element having emission lines in the EUV range, in the form of droplets, slabs, ribbons, streams, or clusters of the material, with an amplified beam of light, which may be referred to as a drive laser. For this process, the plasma is typically generated in a sealed container (e.g., a vacuum chamber) and monitored using various types of metrology equipment. Summary of the Invention

[0006] In one aspect, a device for an extreme ultraviolet (EUV) light source includes a body. The body includes a first structure comprising a first wall; and a second structure comprising a second wall permanently bonded to the first wall. An interior of the body is at least partially defined by the first wall and the second wall. The first wall comprises a first metallization material, and the second wall comprises a second metallization material having a different thermal conductivity than the first metallization material. The interior of the body is configured to be fluidically connected to a target supply system of the EUV light source.

[0007] Implementations may include one or more of the following features.

[0008] The first end of the first wall and the second end of the second wall may be permanently joined at a brazed joint.

[0009] The first metallization material may include molybdenum (Mo), and the second metallization material may include stainless steel.

[0010] The apparatus may further include a temperature control system configured to control the temperature of at least one of the first wall and the second wall. The temperature control system may include a heating system configured to be thermally coupled to the first wall and a cooling system configured to be thermally coupled to the second wall. The second metallization material may have a lower thermal conductivity than the first metallization material.

[0011] The second metallization material may have a lower thermal conductivity than the first metallization material. The first wall may extend from a first end to a second end, and the second wall may extend from a first end to a second end. The first end of the first wall may be brazed to the second end of the second wall. The device may further include: an O-ring at the first end of the second wall; and a removable cap configured to be retained by the O-ring.

[0012] The second metallization material may have a lower thermal conductivity than the first metallization material. The first wall may extend from a first end to a second end, and the second wall may extend from a first end to a second end. The first end of the first wall may be brazed to the second end of the second wall. The device may further include at least one port extending from the second wall. The at least one port may include the second metallization material. The second metallization material may include stainless steel.

[0013] The first metallization material may include a first coefficient of thermal expansion, and the second metallization material may include a second coefficient of thermal expansion.

[0014] The outer side of the first wall may be permanently joined to the inner side of the second wall.

[0015] The body may further include a third structure comprising a third wall. The third wall may include an inner surface and an outer surface. The inner surface of the third wall may be permanently bonded to the outer surface of the second wall. The third wall may include a second metallized material. The apparatus may further include a temperature control system configured to control the temperature of at least one of the first wall, the second wall, and the third wall. The thermal conductivity of the second metallized material may be lower than the thermal conductivity of the first metallized material. The temperature control system may include a heating system configured to be thermally coupled to the first wall; and a cooling system configured to be thermally coupled to the second wall and the third wall. The third wall may be between the second wall and the cooling system.

[0016] The device may be a target material reservoir configured to hold the target material within the body. The target material may emit EUV light when in a plasma state.

[0017] The device may be a connection assembly. The first structure may include at least a first port, and the second structure may include at least a second port. The first port and the second port may be in fluid communication with each other. The device may be configured to provide a fluid path between an external device coupled to the second port and a reservoir coupled to the first port.

[0018] In another aspect, an EUV light source includes a target supply system. The target supply system includes: a droplet generator configured to generate a target stream; at least one device including an interior region configured to be fluidically coupled to the droplet generator; and a container configured to receive a target from the droplet generator. The target includes a target material that emits EUV light when in a plasma state. The device includes: a first structure including a first wall; and a second structure including a second wall permanently bonded to the first wall. The interior region is at least partially defined by the first wall and the second wall. The first wall includes a first metallization material, and the second wall includes a second metallization material having a different thermal conductivity than the first metallization material.

[0019] Implementations may include one or more of the following features.

[0020] The EUV light source may further include a light source configured to generate light pulses having energy sufficient to convert at least some of the target material in the target into a plasma state in which the target material emits EUV light.

[0021] The at least one device may be a target material reservoir configured to hold a target material in an interior region. The target supply system may further include at least one valve. The at least one valve may be configured to fluidically connect or disconnect the interior region of the target material reservoir from the droplet generator.

[0022] The at least one device may be a connection assembly. The first structure may include at least a first port, and the second structure may include at least a second port. The first port and the second port may be in fluid communication with each other. The target supply system may further include: an external device coupled to the second port; and a reservoir coupled to the first port. The reservoir may be configured to hold the target material in the inner cavity and may be fluidically coupled to the droplet generator. The connection assembly may be configured to provide a fluid path between the external device and the reservoir. The external device may be a vacuum system or a gas supply system.

[0023] In another aspect, a target delivery system for an EUV light source includes: a droplet generator configured to generate a target stream; and at least one device including an interior region configured to be fluidically coupled to the droplet generator. The target comprises a target material that emits EUV light when in a plasma state. The device includes: a first structure comprising a first wall; and a second structure comprising a second wall permanently bonded to the first wall. The interior region is at least partially defined by the first and second walls. The first wall comprises a first metallization material, and the second wall comprises a second metallization material having a different thermal conductivity than the first metallization material.

[0024] Implementations may include one or more of the following features.

[0025] The at least one device may be a target material reservoir configured to hold a target material within an interior region.

[0026] The target supply system may further include at least one valve. The at least one valve may be configured to fluidically connect or disconnect the interior region of the at least one device from the droplet generator.

[0027] The at least one device may be a connection assembly. The first structure may include at least a first port, and the second structure may include at least a second port. The first port and the second port may be in fluid communication with each other.

[0028] Implementations of any of the above technologies may include EUV light sources, systems, methods, processes, devices, or apparatuses. Details of one or more implementations are set forth in the accompanying drawings and the following description. Other features will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a block diagram of an extreme ultraviolet (EUV) light source.

[0030] Figure 2 is a block diagram of the target material tank.

[0031] Figure 3 is a block diagram of a metal connection assembly.

[0032] Figure 4 is a block diagram of the target provisioning system.

[0033] Figure 5 is a block diagram of another target provisioning system.

[0034] Figure 6A is a cross-sectional view of another target material tank in the XY plane.

[0035] Figure 6B yes Figure 6A Cross-sectional view of the target material reservoir in the XZ plane.

[0036] Figure 6C yes Figure 6A A perspective view of a target material storage tank.

[0037] Figure 7 This is a block diagram of another EUV light source. DETAILED DESCRIPTION

[0038] refer to Figure 1 , a block diagram of an extreme ultraviolet (EUV) light source 100 is shown. The light source 100 includes a container 109 (e.g., a vacuum chamber or vacuum vessel), a light source 105 that generates a light beam 106, and a target supply system 140. The target supply system 140 includes a target material reservoir 144 having an interior region 103 configured to hold a target material. The target supply system 140 also includes a droplet generator 142 that receives the target material from the interior 103 of the target material reservoir 144. The target supply system 140 also includes a pressure management system 130.

[0039] The target material reservoir 144 is made of more than one metallized material. Figure 1 In the example shown in FIG, target material reservoir 144 includes a first structure 146 and a second structure 148 that are permanently joined at an interface 150. Interface 150 may be, for example, a brazed joint. First structure 146 and second structure 148 are three-dimensional solid structures, each made of a different metallized material. As described below, using more than one metallized material to form target material reservoir 144 enhances the safety and usability of target material reservoir 144 and allows for a greater number of options for components.

[0040] In operation, a droplet generator 142 delivers a target stream 121 to the interior 101 of a container 109. The droplet generator 142 includes a droplet delivery system, such as a nozzle, and may include one or more pressurized containers containing a liquid target material delivered from a target material reservoir 144. The interaction of the light beam 106 and the target material in a target 121p (one of multiple targets in the stream 121) at a plasma generation location 123 produces a plasma 196 that emits EUV light 197. The light beam 106 is generated by a light source 105 and delivered to the interior 101 via an optical path 107. The plasma 196 generated by the interaction between the light beam 106 and the target material in the target 121p is supplied to a lithography tool 199. The target 121p includes a target material, which is any material having emission lines in the EUV range when in a plasma state. The target material may be, for example, tin, lithium, or xenon. Other materials may also be used as the target material. For example, elemental tin can be used as pure tin (Sn); as a tin compound, such as SnBr4, SnBr2, SnH4; as a tin alloy, such as a tin-gallium alloy, a tin-indium alloy, a tin-indium-gallium alloy or any combination of these alloys.

[0041] The interior 103 of the reservoir 144 is fluidically coupled to the droplet generator 142 via a fluid communication connection 155. The fluid communication connection 155 is any type of device, structure, or system that allows the target material to flow from the interior 103 of the reservoir 144 to the droplet generator 142. For example, the fluid communication connection 155 can be a tube or a pipe, or a combination of these elements. The fluid communication connection 155 can be made of any material capable of transporting the target material. The fluid communication connection 155 can include a regulating device, such as Figure 4 4. The regulating device 452a is shown in FIG. The regulating device can be configured to control the flow of the target material through the fluid communication connection 155 by, for example, opening, closing, or partially blocking the fluid communication connection 155. In some embodiments, the regulating device can include a freeze valve. In other implementations, the target material reservoir 144 is directly adjacent to the droplet generator 142, so that the target material reservoir 144 supplies the target material to the droplet generator 142 without using the fluid communication connection 155.

[0042] refer to Figure 2 , shows a side cross-sectional view of the target material storage tank 244. The target material storage tank 244 is a target material storage tank 144 ( Figure 1 ) implementation method.

[0043] Target material reservoir 244 includes a first structure 246 and a second structure 248. First structure 246 and second structure 248 are solid, three-dimensional bodies that partially define an interior region 203 within target material reservoir 244. Interior region 203 holds target material 220. Target material 220 includes a target material that emits EUV light when in a plasma state and may also include various impurities.

[0044] The first structure 246 is made of a first metallized material. The second structure 248 is made of a second metallized material. The first metallized material and the second metallized material are different metallized materials. The first metallized material and the second metallized material have different thermal conductivities. The thermal conductivity of the second metallized material can be lower than the thermal conductivity of the first metallized material. For example, the first metallized material can be molybdenum (Mo), which has a thermal conductivity of 138 watts per meter Kelvin at 20 degrees Celsius, and the second metallized material can be stainless steel, which has a thermal conductivity of 14.4 watts per meter Kelvin at 20 degrees Celsius. As discussed below, this configuration allows the storage tank 244 to operate in a safe and efficient manner, and also provides greater flexibility in the configuration of the various components of the storage tank 244.

[0045] Furthermore, the first metallization material and the second metallization material may have different coefficients of thermal expansion. The coefficient of thermal expansion is a material property that defines the extent to which a material expands when heated or contracts when cooled. For example, the first metallization material may be molybdenum, which has a coefficient of thermal expansion of 4.8×10 -6 per Kelvin, and the second metallization material may be stainless steel, which has a thermal expansion coefficient of approximately 14.4×10 -6 Second coefficient of thermal expansion per Kelvin. Some sealing technologies are not strong enough to prevent or minimize relative movement between two joined metals, each of which has a different coefficient of thermal expansion under temperature changes. On the other hand, the first wall 216 and the second wall 218 can be joined at the interface 250 by brazing. Brazing forms a seal that is strong enough to minimize or prevent relative movement between two joined metals with different coefficients of thermal expansion under temperature changes. In particular, brazing forms a seal that minimizes or prevents relative movement between the first wall 216 and the second wall 218 during temperature changes. This reduces wear at the interface 250 and improves the sealing performance of the interface 250.

[0046] The first structure 246 includes a first wall 216 and a base portion 217. The first wall 216 extends in the Y direction from a second end 216b joined to the base portion 217 to a first end 216a. The base portion 217 defines a port 233, which is made of a first metallized material. The port 233 fluidly couples the interior region 203 to a fluid communication connector, such as, for example, a target material reservoir connector 455 ( Figure 4 ) or fluid communication connector 555 ( Figure 5 Port 233 allows fluid (eg, target material) in interior region 203 to flow from target material reservoir 244 into the fluid communication connection.

[0047] The first wall 216 and the base portion 217 are made of a first metallized material. The second structure 248 includes a second wall 218. The second wall 218 is made of a second metallized material. The second wall 218 extends from the second end 218b to the first end 218a in the Y direction. Each of the first wall 216 and the second wall 218 is a three-dimensional solid body. The first wall 216 and the second wall 218 are in the XZ direction (in Figure 2 In the example of FIG, the first wall 216 and the second wall 218 have substantially the same cross-sectional dimensions in a plane perpendicular to the page. For example, the first wall 216 and the second wall 218 may have a circular, square, or rectangular cross-section in the XZ plane. The reservoir 244 may be, for example, a cuboid or a cylinder. Figure 2 In the example shown, the first wall 216 and the second wall 218 have approximately the same diameter in the XZ plane, and the diameters of the first wall 216 and the second wall 218 are substantially constant in the Y direction. Other implementations are also possible. For example, the diameters of the first wall 216 and / or the second wall 218 in the XY plane can vary along the Y direction. Furthermore, in some implementations, the base portion 217 is not part of the first structure 246. In these implementations, the first structure 246 is open at the second end 216b. For example, the shape of the first structure 246 can be approximately hemispherical.

[0048] The second wall 218 is permanently joined to the first wall 216 at the interface 250. For example, the first wall 216 and the second wall 218 can be permanently joined by melting a filler metallization material (the filler metallization material having a lower melting point than the first metallization material and the second metallization material) between the first wall 216 and the second wall 218, such that when the filler metallization material cools to a solid form, the first wall 216 and the second wall 218 are permanently joined. This method of permanently joining the first metallization material to the second metallization material is known as brazing. Brazing forms a strong seal that prevents moisture and oxygen from entering the interior region 203. Figure 2 In the example shown in FIG, the first end 216a of the first wall 216 is brazed to the second end 218b of the second wall 218 at an interface 250. The interface 250 is a continuous joint such that the reservoir 244 is a single sealed body.

[0049] exist Figure 2In the example shown, an O-ring 212 is positioned at the first end 218a of the second wall 218. The O-ring 212 is a continuous piece or ring of rubber or elastomer that surrounds the circumference of the inside of the first end 218a of the second wall 218. The O-ring 212 is used to seal the top portion to the second wall 218. The top portion may be a removable cover (referred to as removable cover 215) configured to be retained by the O-ring 212. The O-ring is thermally compatible with the second metallized material and, when the molten target material is in the interior region 203 of the target material reservoir 244, the second metallized material is not elevated to the same high temperature as the first metallized material. When the removable cover is closed on the target material reservoir 244, the O-ring reduces leakage of the target material 220. The removable cover 215 allows the target material to be placed in the interior region 203 of the target material reservoir 244. For example, the target material may be placed into the interior region 203 by opening the removable cover 215, placing the target material into the target material reservoir 244, and then resealing the removable cover 215 to the O-ring 212. The removable cover 215 is made of a second metallized material.

[0050] Target material storage tank 244 includes a temperature control system 231. Temperature control system 231 controls the temperature of first wall 216 and / or second wall 218. By controlling the temperature of first wall 216 and / or second wall 218, temperature control system 231 also controls the temperature in interior region 203.

[0051] The temperature control system 231 includes a heating system 232 that is configured to be thermally coupled to the first wall 216. The heating system 232 can be a plurality of discrete heating elements positioned at different locations relative to the first wall 216, or it can be a single heating element. The heating system 232 can be thermally coupled to the first wall 216 through direct physical contact, but this is not required. By heating the first wall 216, the heating system 232 also heats the interior region 203 including the target material 220. This allows the target material 220 to be converted into a melted, fluid, or molten state, which enables the target material 220 to flow, or to be maintained in this molten state.

[0052] Temperature control system 231 also includes a cooling system 234 that is thermally coupled to second wall 218. Cooling system 234 can be a plurality of separate cooling elements positioned at different locations relative to second wall 218, or it can be a single cooling element. For example, cooling system 234 can include a fluid channel within a duct, such as water or air. Cooling system 234 cools second wall 218 and removable cover 215. For example, cooling system 234 can be cooled to a touch-safe temperature of approximately 40°C to 50°C.

[0053] The relatively low thermal conductivity of the second metallized material allows the second wall 218 to be cooled to a touch-safe temperature. This allows an operator to manipulate the removable cover 215 and interact with the reservoir 214 in a safe manner. For example, the target material 220 can be replenished or installed by opening the cover 215 and placing a solid block of the target material in the interior area 203. By cooling the removable cover 215 to a touch-safe temperature, replacement procedures can be performed safely and efficiently without lowering the temperature of the first wall 216. Furthermore, the ability to lower the temperature of the second wall 218 (due to its relatively low thermal conductivity) allows a wider variety of materials to be used for the O-ring 212. Specifically, because the second wall 218 and removable cover 215 can be cooled to a touch-safe temperature, the O-ring 212 does not necessarily have to withstand high temperatures and can be made of a relatively less heat-resistant material. Furthermore, because the first structure 246 and the port 233 are made of the first metallized material, the coupler, fastener, or other coupling device coupled to the port 233 can also be made of the first metallized material.

[0054] The target material reservoir 244 also includes a vacuum port 236. The vacuum port 236 is configured to be connected to a vacuum system (not shown). This allows the interior region 203 to be maintained at a pressure below atmospheric pressure or at a specific pressure desired by the user.

[0055] refer to Figure 3 , shows a side cross-sectional view of a metal connection assembly 344. The metal connection assembly 344 includes a first structure 346 permanently attached to a second structure 348 at an interface 350. The first structure 346 and the second structure 348 are solid three-dimensional bodies that at least partially define the interior region 303.

[0056] First structure 346 is made of a first metallization material. Second structure 348 is made of a second metallization material. The first metallization material and the second metallization material are different metallization materials. The first metallization material and the second metallization material have different thermal conductivities. The thermal conductivity of the second metallization material can be lower than the thermal conductivity of the first metallization material. Furthermore, the first metallization material and the second metallization material can have different coefficients of thermal expansion. The first metallization material can be, for example, molybdenum, and the second metallization material can be, for example, stainless steel. As described below, this provides greater flexibility in the configuration of the various components of metal connection assembly 344.

[0057] The first structure 346 includes a first wall 316. The first wall 316 extends from the second end 316b to the first end 316a in the Y direction. The first structure 346 is open at the second end 316b. The open second end 316b is Figure 3 The opening 335 is marked as 335 and is referred to as opening 335. The opening 335 provides a fluid connection point for the metal connection component 344. Figure 3 In the example shown in FIG, the first structure 346 is open at the second end 316b, but other implementations are possible. For example, the first structure 346 may include a base portion that defines a port, similar to Figure 2 base portion 217 and port 233 .

[0058] The first wall 316 includes an outer side 316c facing away from the interior area 303. The second structure 348 includes a second wall 318. The second wall 318 extends from a second end 318b to a first end 318a. The second wall 318 includes an inner side 318c facing the interior area 303. The first wall 316 and the second wall 318 are three-dimensional solid bodies having approximately equal cross-sectional sizes and shapes in the XZ plane. For example, the first wall 316 and the second wall 318 can have circular, square, or rectangular cross-sections in planes inside and outside the page. The first end 316a of the first wall 316 and the second end 318b of the second wall 318 are permanently joined at an interface 350. The interface 350 can be formed by brazing. Figure 3 In the example shown, the outer side 316 c of the first wall 316 at the first end 316 a is directly brazed to the inner side 318 c of the second wall 318 at the second end 318 b to form the interface 350 .

[0059] The second structure 348 also includes a top portion 315. The top portion 315 and the second wall 318 define one or more ports 338. The top portion 315 also defines a gas or vacuum port 336. A fluid (such as a gas, liquid, or a flowable substance comprising gas and / or liquid) can flow through the interior area 303 of the metal connection assembly 344. For example, the fluid can flow from the port 336 to the opening 335 and / or flow from the one or more ports 338 into the interior area 303 and through the opening 335. The port 336 can be connected to a vacuum system (not shown) that is configured to control the pressure in the interior area. The port 336 can also be connected to a gas supply system (not shown) that supplies gas to the interior area 303. In the example shown, the port 338 includes a gasket 339 that helps connect the port 336 to an external device. The port 336 can be connected to an external device, such as, for example, a gas supply system or a vacuum system. The second end 316b of the first wall 316 can be connected to a reservoir or container, such as the container 547 ( Figure 5 ).

[0060] The configuration of metal connection assembly 344 allows port 388 and port 336 to be made of a material that is the same as or thermally similar to the material used on many external devices. Because second structure 348, port 336, and port 338 are made of a second metallized material, the connector used to connect to port 338 and / or port 336 can also be made of the second metallized material. For example, the second metallized material can be stainless steel, and the first metallized material can be molybdenum (Mo). Many external devices use stainless steel connectors. In this example, ports 338 and port 336 are connected to an external device that has a stainless steel connector at a stainless steel-stainless steel interface. In this example, the connection interface is made of two identical metals. This allows the entire assembly to be heated to relatively high temperatures (e.g., 300°C or higher) without degrading the performance of the connector. Furthermore, this contrasts with some existing systems in which the entire structure (including the port for connecting to the external device) is made of a metallized material (such as Mo) with a relatively high thermal conductivity, which is greater than the thermal conductivity of the material (e.g., stainless steel) typically used to connect the external device to the port connector. In these existing systems, the connector of the external device and the port on the structure are made of different metals, which can lead to degradation of the connection.

[0061] refer to Figure 4 , a target supply system 440 is shown. The target supply system 440 is an example of a system in which a multi-metal reservoir or bi-metal reservoir or device can be used. The target supply system 440 includes a perfusion reservoir 416, a target material reservoir 444, a reservoir 447, and a droplet generator 142 ( Figure 1 ). In some embodiments, there may be multiple reservoirs 447, and one or more reservoirs may be pressurized. Target material reservoir 444 is made of two or more different metallized materials and may be, for example, reservoir 144 or reservoir 244. Fluid communication connection 455 fluidly connects perfusion reservoir 416, target material reservoir 444, reservoir 447, and droplet generator 142. Fluid communication connection 455 is a fluid communication connection 155 ( Figure 1 ) is implemented. Figure 4 In the example shown, tank 444 is a refill tank.

[0062] Fluid communication connection 455 includes a regulating device 452a between storage tank 444 and reservoir 447. Regulating device 452a is configured to regulate, direct, or control the flow of target material from target material storage tank 444 to reservoir 447. In some implementations, fluid communication connection 455 also includes a regulating device 452b between perfusion tank 416 and target material storage tank 444. In implementations including regulating device 452b, regulating device 452b is configured to regulate, direct, or control the flow of target material from perfusion tank 416 to target material storage tank 444. Each regulating device 452a, 452b can be, for example, a valve. If each regulating device 452a, 452b is a valve, the valve can be a fluid valve, which can be, for example, hydraulic, pneumatic, manually operated, solenoid-driven, or motor-driven. In some implementations, one or both regulating devices 452a, 452b is or includes a cryostat valve.

[0063] The priming reservoir 416 supplies the target material to the target material reservoir 444, and the target material reservoir 444 supplies the target material to the reservoir 447. The reservoir 447 supplies the target material to the droplet generator 142. The target supply system 440 is configured to allow the droplet generator 142 to operate while the reservoir 444 is being replenished. For example, the reservoir 444 can be replenished when the regulating device 452 is in a state that prevents the target material from flowing between the target material reservoir 444 and the reservoir 447. During this time, the priming reservoir 416 either replenishes the target material reservoir 444 with the target material or generates a fluid target material from the solid target material. However, the reservoir 447 continues to supply the target material to the droplet generator 142. When the supply of target material in the reservoir 447 is low, the regulating device 452 changes state to allow the target material to flow from the target material reservoir 444 to the reservoir 447. The target material flows into the reservoir 447, and thereby the reservoir 447 is replenished, while the droplet generator 142 continues to produce the stream 121 ( Figure 1 ).

[0064] Target supply system 440 is one example of a system in which a reservoir made of more than one metallized material, such as reservoir 144 or reservoir 244, may be used. Other implementations are also possible. For example, target supply system 440 may include two or more separate reservoirs between target material reservoir 444 and droplet generator 142. The two or more reservoirs are fluidly connected to each other via fluid communication connection 455, and to droplet generator 142 and target material reservoir 444, and may include a regulating device between each of these elements. In addition, reservoirs made of more than one metal may be provided in different configurations. Figure 4For example, the reservoir can be directly connected to the droplet generator 142 so that a bimetallic or multimetallic reservoir acts as a reservoir.

[0065] refer to Figure 5 , a target supply system 540 is shown. The target supply system 540 is another example of a system in which a multi-metallic reservoir or bi-metallic reservoir or device can be used. The target supply system 540 includes a target material reservoir 244, a metal connection assembly 344, a reservoir 547, a fluid communication connection 555, and a droplet generator 142. The fluid communication connection 555 fluidly connects the target material reservoir 244, the reservoir 547, and the droplet generator 142. For example, the fluid communication connection 555 can be a tube or a pipe, or a combination of these elements. In Figure 5 In the example shown, target material reservoir 244 acts as a refill reservoir. Specifically, target material reservoir 244 is configured to refill reservoir 547 with target material via fluid communication connection 555 when the target supply in reservoir 547 is low. Metal connection assembly 344 provides a gas connection to reservoir 547.

[0066] Regulating device 552a is coupled to fluid communication connection 555 between reservoir 244 and reservoir 547. Regulating device 552b is coupled to fluid communication connection 555 between reservoir 547 and droplet generator 142. Regulating device 552a and regulating device 552b are configured to regulate, direct, or control the flow of target material from target material reservoir 244 to reservoir 547 and from reservoir 547 to droplet generator 142, respectively.

[0067] Each of the regulating devices 552a, 552b can be, for example, a valve. If each of the regulating devices 552a, 552b is a valve, the valve can be a fluid valve, which can be, for example, hydraulic, pneumatic, manually operated, solenoid-driven, or motor-driven. In some implementations, each of the regulating devices 552a, 552b is or includes a cryostat valve.

[0068] The fluid communication connection 555 and each of the regulating devices 552a and 552b can be made of a first metallized material so that the first structure 246 of the storage tank 244, the fluid communication connection 555 and each of the regulating devices 552a and 552b are made of a material that does not adversely affect the target material.

[0069] The target material reservoir 244 holds the target material. The target material flows out of the target material reservoir 244 through the port 233, into the fluid communication connection 555, and into the reservoir 547. The reservoir 547 supplies the target material to the droplet generator 142. The target supply system 540 allows the droplet generator 142 to operate while the reservoir 244 is being replenished. For example, when the regulating device 552a is in a state that prevents the target material from flowing between the target material reservoir 244 and the reservoir 547, the reservoir 244 can be replenished. During this time, the target material reservoir 244 is replenished with solid target material, and a fluid target material is generated from the solid target material. For example, as described above, the top portion of the reservoir 244 can be a removable cover 215. In these embodiments, the reservoir is replenished with solid target material by opening the top portion, placing the solid target material in the reservoir 244, and resealing the cover 215 to the reservoir 244. However, reservoir 547 may still contain an adequate supply of target material and continue to supply target material to droplet generator 142. When the supply of target material in reservoir 547 is low, regulating device 552a changes state to allow target material to flow from target material reservoir 244 to reservoir 547. Target material flows into reservoir 547, thereby replenishing reservoir 547, while droplet generator 142 continues to generate stream 121 ( Figure 1 ).

[0070] The metal connection assembly 344 supplies fluid (e.g., gas, liquid, or liquid including gas) to or removes fluid from the reservoir 547. The first structure 346 of the metal connection assembly 344 is attached to the reservoir 547, wherein the opening 335 is in fluid communication with the interior of the reservoir 547. The port 336 is connected to an external device 551 using a connector 553 made of a second metallized material. Therefore, the port 336 and the connector 553 are made of the same metallized material. The external device can be, for example, a vacuum system or a gas supply. The reservoir 547 can be made of the first metallized material so that the first structure 346 of the metal connection assembly 344 and the reservoir 547 are made of the same material.

[0071] The target supply system 540 is an example of a system in which a reservoir made of more than one metallized material may be used, including the reservoir 244 and the metal connection assembly 344. Other implementations are also possible. For example, the target supply system 540 may include two or more separate reservoirs between the target material reservoir 244 and the droplet generator 142. The two or more reservoirs are fluidly connected to each other, the droplet generator 142, and the target material reservoir 244 via fluid communication connections 555, and may include a regulating device between each of these elements. Each of the two or more reservoirs can be connected to one or more of the metal connection assemblies 344 to provide one or more gas connections or vacuums to each of the two or more reservoirs. In addition, the reservoirs made of more than one metal can be connected in different ways. Figure 5 For example, the reservoir can be directly connected to the droplet generator 142 so that a bimetallic or multimetallic reservoir acts as a reservoir.

[0072] refer to Figures 6A to 6C , another target material storage tank 644 is shown. Figure 6A is a side cross-sectional view of the target material reservoir 644 in the XY plane. Figure 6B It is along Figure 6A 8 is a cross-sectional view of the target material reservoir 644 taken along line BB' in the XZ plane. Figure 6C 644. In addition to the target material storage tank 644 also includes a third wall 619, the target material storage tank 644 and the target material storage tank 244 ( Figure 2 As described below, the third wall 619 provides an additional barrier between the interior region 203 and the cooling system 234. The presence of the third wall 619 reduces the thermal gradient across the second wall 218.

[0073] The third wall 619 is a three-dimensional solid body. Like the second wall 218, the third wall 619 is made of the second metallized material. The third wall 619 extends from the second end 619b to the first end 619a in the Y direction. The third wall 619 includes an inner surface 619c and an outer surface 619d. Figures 6A to 6C In the example of FIG, the third wall 619 and the second wall 218 each have a circular cross-sectional shape in the XZ plane. Other implementations are also possible. For example, the second wall 218 and the third wall 219 may have a square or rectangular cross-sectional shape in the XZ plane.

[0074] The inner surface 619c of the third wall 619 can be permanently joined to the outer surface 218c of the second wall 218. For example, portions of the inner surface 619c and the outer surface 218c can be permanently joined by melting a filler metallization material (the filler metallization material having a lower melting point than the second metallization material) between the third wall 619 and the second wall 218, such that when the filler metallization material cools to a solid form, the third wall 619 and the second wall 218 are permanently joined.

[0075] Cooling system 234 is thermally coupled to outer surface 619d. In some cases, there is a relatively large temperature difference between interior region 203 and cooling system 234. This temperature gradient can cause compressive and tensile stresses to be generated on objects (such as second wall 218) between interior region 203 and cooling system 234. The compressive and / or tensile stresses may cause the objects to deform. By placing third wall 619 between second wall 218 and cooling system 234, the distance between interior region 203 and cooling system 234 is increased, and the thermal gradient is reduced. Reducing the thermal gradient reduces the compressive and tensile stresses on second wall 218, thereby reducing the likelihood of deformation of the material of second wall 218.

[0076] refer to Figure 7 , shows the implementation of LPP EUV light source 700. LPP EUV light source 700 is EUV light source 100 ( Figure 1 The EUV light source 700 includes a target supply system 727. The target supply system 727 may include a bimetallic or multimetallic target material reservoir, such as the target material reservoir 144 or the reservoir 244.

[0077] The LPP EUV light source 700 is formed by irradiating a target mixture 714 at a plasma formation region 705 with an amplified light beam 710 that travels along a beam path toward the target mixture 714. Figure 1 The target material in the target of the stream 121 discussed above can be or include a target mixture 714. A plasma formation region 705 is within an interior 707 of a vacuum chamber 730. When the amplified light beam 710 strikes the target mixture 714, the target material within the target mixture 714 is converted into a plasma state having elements with emission lines in the EUV range. The resulting plasma has certain properties that depend on the composition of the target material in the target mixture 714. These properties can include the wavelength of EUV light generated by the plasma and the type and amount of debris released from the plasma.

[0078] The light source 700 includes a driver laser system 715 that generates an amplified light beam 710 due to population inversion within one or more gain media of the laser system 715. The light source 700 includes a beam delivery system between the laser system 715 and the plasma formation region 705, the beam delivery system including a beam delivery system 720 and a focusing assembly 722. The beam delivery system 720 receives the amplified light beam 710 from the laser system 715, controls and modifies the amplified light beam 710 as needed, and outputs the amplified light beam 710 to a focusing assembly 722. The focusing assembly 722 receives the amplified light beam 710 and focuses the light beam 710 onto the plasma formation region 705.

[0079] In some implementations, laser system 715 may include one or more optical amplifiers, lasers, and / or lamps for providing one or more main pulses and, in some cases, one or more prepulses. Each optical amplifier includes a gain medium capable of optically amplifying a desired wavelength with high gain, an excitation source, and internal optics. The optical amplifier may or may not have laser mirrors or other feedback devices that form a laser cavity. Thus, due to population inversion in the laser amplifier gain medium, laser system 715 produces an amplified light beam 710 even without a laser cavity. Furthermore, if a laser cavity is present to provide sufficient feedback to laser system 715, laser system 715 can produce amplified light beam 710 as a coherent laser beam. The term "amplified light beam" includes one or more of the following: light from laser system 715 that is merely amplified but not necessarily coherently laser oscillated; and light from laser system 715 that is amplified and also coherently laser oscillated.

[0080] The optical amplifier in the laser system 715 can include a fill gas comprising CO2 as a gain medium and can amplify light having a wavelength between about 9100 nm and about 11000 nm, particularly about 10600 nm, with a gain of greater than or equal to 900 times. Suitable amplifiers and lasers for use in the laser system 715 can include pulsed laser devices, such as pulsed gas discharge CO2 laser devices, that generate radiation at about 9300 nm or about 10600 nm, for example, with DC or RF excitation, and operate at relatively high power (e.g., 10 kW or greater) and a high pulse repetition rate (e.g., 40 kHz or greater). The pulse repetition rate can be, for example, 50 kHz. The optical amplifier in the laser system 715 can also include a cooling system (such as water), which can be used when the laser system 715 is operated at higher power.

[0081] The light source 700 includes a collector mirror 735 having an aperture 740 to allow the magnified light beam 710 to pass through and reach the plasma formation region 705. The collector mirror 735 can be, for example, an ellipsoidal mirror having a primary focus at the plasma formation region 705 and a secondary focus (also referred to as an intermediate focus) at an intermediate position 745, at which EUV light can be output from the light source 700 and input to, for example, an integrated circuit lithography tool (not shown). The light source 700 can also include an open-ended hollow conical shield 750 (e.g., a gas cone) that tapers from the collector mirror 735 toward the plasma formation region 705 to reduce the amount of plasma-generated debris that enters the focusing assembly 722 and / or the beam delivery system 720 while allowing the magnified light beam 710 to reach the plasma formation region 705. To this end, a gas flow can be provided in the shield that is directed toward the plasma formation region 705.

[0082] The light source 700 may also include a main controller 755 connected to a droplet position detection feedback system 756, a laser control system 757, and a beam control system 758. The light source 700 may include one or more target or droplet imagers 760 that provide outputs indicating the position of a droplet, for example, relative to the plasma formation region 705, and provide this output to the droplet position detection feedback system 756. The droplet position detection feedback system may, for example, calculate droplet position and trajectory, from which droplet position errors may be calculated on a droplet-by-droplet basis or as an average. Thus, the droplet position detection feedback system 756 provides the droplet position errors as inputs to the main controller 755. Thus, the main controller 755 may provide laser position, direction, and timing correction signals to the laser control system 757, which may be used to control the laser timing circuit and / or the beam control system 758 to control the position and shape of the amplified beam of the beam delivery system 720, thereby changing the position and / or focusing power of the beam focal point within the vacuum chamber 730.

[0083] The supply system 725 includes a target material delivery control system 726 that is operable to respond to signals from the main controller 755, for example, to modify the release point of droplets released by the target supply system 727 to correct for errors in the droplets reaching the desired plasma formation region 705.

[0084] In addition, the light source 700 may include light source detectors 765 and 770 that measure one or more EUV light parameters, including but not limited to pulse energy, energy distribution as a function of wavelength, energy within a specific wavelength band, energy outside a specific wavelength band, and angular distribution of EUV intensity and / or average power. The light source detector 765 generates a feedback signal for use by the main controller 755. For example, the feedback signal can indicate errors in parameters such as the timing and focus of the laser pulses to properly intercept droplets at the correct location and time for effective and efficient generation of EUV light.

[0085] The light source 700 may also include a pilot laser 775, which can be used to align various sections of the light source 700 or assist in steering the amplified light beam 710 toward the plasma formation region 705. In conjunction with the pilot laser 775, the light source 700 includes a metrology system 724, which is placed within the focusing assembly 722 to sample a portion of the light from the pilot laser 775 and the amplified light beam 710. In other implementations, the metrology system 724 is placed within the beam delivery system 720. The metrology system 724 can include optical elements that sample or redirect a subset of the light, such optical elements being made of any material that can withstand the power of the pilot laser beam and the amplified light beam 710. The beam analysis system is formed by the metrology system 724 and the main controller 755, as the main controller 755 analyzes the sampled light from the pilot laser 775 and uses this information to adjust components within the focusing assembly 722 via the beam control system 758.

[0086] Thus, in summary, light source 700 generates an amplified light beam 710 that is directed along a beam path to illuminate a target mixture 714 at plasma formation region 705, thereby converting the target material within mixture 714 into a plasma that emits light in the EUV range. Amplified light beam 710 operates at a specific wavelength (also referred to as a drive laser wavelength) determined based on the design and characteristics of laser system 715. Furthermore, amplified light beam 710 can be a laser beam when the target material provides sufficient feedback to laser system 715 to generate coherent laser light, or if drive laser system 715 includes suitable optical feedback to form a laser cavity.

[0087] The following terms may be used to further describe implementations of the present disclosure:

[0088] 1. An apparatus for an extreme ultraviolet (EUV) light source, the apparatus comprising:

[0089] The subject, which includes:

[0090] a first structure comprising a first wall; and

[0091] a second structure comprising a second wall permanently joined to the first wall, wherein an interior of the body is at least partially defined by the first wall and the second wall, the first wall comprises a first metallized material, and the second wall comprises a second metallized material having a different thermal conductivity than the first metallized material, and wherein

[0092] The interior of the body is configured to be fluidly connected to a target supply system of the EUV light source.

[0093] 2. The device of clause 1, wherein the first end of the first wall and the second end of the second wall are permanently joined at a brazed joint.

[0094] 3. The device of clause 1, wherein the first metallization material comprises molybdenum (Mo) and the second metallization material comprises stainless steel.

[0095] 4. The apparatus according to clause 1, further comprising:

[0096] A temperature control system is configured to control the temperature of at least one of the first wall and the second wall.

[0097] 5. The apparatus according to clause 4, wherein the temperature control system comprises:

[0098] a heating system configured to be thermally coupled to the first wall; and

[0099] A cooling system is configured to be thermally coupled to the second wall, wherein the thermal conductivity of the second metallization is lower than the thermal conductivity of the first metallization.

[0100] 6. The apparatus of clause 1, wherein the second metallization material has a lower thermal conductivity than the first metallization material, the first wall extends from a first end to a second end, the second wall extends from a first end to a second end, the first end of the first wall is brazed to the second end of the second wall, and the apparatus further comprises:

[0101] an O-ring at the first end of the second wall; and

[0102] A removable cap is configured to be retained at the O-ring.

[0103] 7. The apparatus of clause 1, wherein the second metallization material has a lower thermal conductivity than the first metallization material, the first wall extends from a first end to a second end, the second wall extends from a first end to a second end, the first end of the first wall is brazed to the second end of the second wall, and the apparatus further comprises:

[0104] At least one port extends from the second wall, the at least one port comprising a second metallization material.

[0105] 8. The device of clause 7, wherein the second metallization material comprises stainless steel.

[0106] 9. The device of clause 1, wherein the first metallization material comprises a first coefficient of thermal expansion and the second metallization material comprises a second coefficient of thermal expansion.

[0107] 10. The device according to clause 1, wherein the outer side of the first wall is permanently joined to the inner side of the second wall.

[0108] 11. The device according to clause 1, wherein the body further comprises:

[0109] a third structure comprising a third wall including an inner surface and an outer surface; and

[0110] Wherein the inner surface of the third wall is permanently bonded to the outer surface of the second wall, and the third wall comprises a second metallization material.

[0111] 12. The apparatus according to clause 11, further comprising:

[0112] A temperature control system is configured to control the temperature of at least one of the first wall, the second wall, and the third wall, and wherein the thermal conductivity of the second metallization is lower than the thermal conductivity of the first metallization.

[0113] 13. The apparatus according to clause 12, wherein the temperature control system comprises:

[0114] a heating system configured to be thermally coupled to the first wall; and

[0115] A cooling system is configured to be thermally coupled to the second wall and the third wall, wherein the third wall is between the second wall and the cooling system.

[0116] 14. The apparatus according to clause 1, wherein the apparatus is a target material reservoir configured to hold a target material inside the body, the target material emitting EUV light when in a plasma state.

[0117] 15. The device according to clause 1, wherein the device is a connection assembly, the first structure comprises at least a first port, the second structure comprises at least a second port, and the first port and the second port are in fluid communication with each other.

[0118] 16. The apparatus of clause 15, wherein the apparatus is configured to provide a fluid path between an external device coupled to the second port and a reservoir coupled to the first port.

[0119] 17. An extreme ultraviolet (EUV) light source, comprising:

[0120] A target provisioning system, comprising:

[0121] a droplet generator configured to generate a target stream, wherein the target comprises a target material that emits EUV light when in a plasma state; and

[0122] At least one device comprising an interior region configured to be fluidically coupled to a droplet generator, the device comprising:

[0123] a first structure comprising a first wall; and

[0124] a second structure comprising a second wall permanently joined to the first wall, wherein an interior region is at least partially defined by the first wall and the second wall, the first wall comprising a first metallization material, and the second wall comprising a second metallization material having a different thermal conductivity than the first metallization material; and

[0125] A container is configured to receive a target from the droplet generator.

[0126] 18. The EUV light source of clause 17, further comprising a light source configured to generate light pulses having energy sufficient to convert at least some target material in the target into a plasma state in which the target material emits EUV light.

[0127] 19. The EUV light source according to clause 17, wherein the at least one device is a target material reservoir configured to hold the target material in the interior region.

[0128] 20. The EUV light source according to clause 19, wherein the target supply system further comprises at least one valve configured to fluidically connect or fluidically disconnect the interior region of the target material reservoir from the droplet generator.

[0129] 21. The EUV light source according to clause 17, wherein the at least one device is a connection assembly, the first structure comprises at least a first port, the second structure comprises at least a second port, and the first port and the second port are in fluid communication with each other.

[0130] 22. The EUV light source according to clause 21, wherein the target supply system further comprises:

[0131] an external device coupled to the second port; and

[0132] a reservoir coupled to the first port, wherein the reservoir is configured to hold a target material in the inner cavity and is fluidly coupled to the droplet generator; and

[0133] Wherein the connection assembly is configured to provide a fluid path between the external device and the reservoir.

[0134] 23. The EUV light source according to clause 22, wherein the external device is a vacuum system or a gas supply system.

[0135] 24. A target supply system for an EUV light source, the target supply system comprising:

[0136] a droplet generator configured to generate a target stream, wherein the target comprises a target material that emits EUV light when in a plasma state; and

[0137] At least one device comprising an interior region configured to be fluidically coupled to a droplet generator, the device comprising:

[0138] a first structure comprising a first wall; and

[0139] A second structure includes a second wall permanently joined to the first wall, wherein the interior region is at least partially defined by the first wall and the second wall, the first wall includes a first metallization material, and the second wall includes a second metallization material having a different thermal conductivity than the first metallization material.

[0140] 25. The target supply system of clause 24, wherein the at least one device is a target material reservoir configured to retain the target material within an interior region.

[0141] 26. The target supply system according to clause 24, further comprising at least one valve configured to fluidically connect or disconnect the interior region of the at least one device from the droplet generator.

[0142] 27. The target supply system according to clause 24, wherein the at least one device is a connection assembly, the first structure comprises at least a first port, the second structure comprises at least a second port, and the first port and the second port are in fluid communication with each other.

[0143] Other implementations are within the scope of the following claims.

Claims

1. A device for an extreme ultraviolet (EUV) light source, the device comprising: The subject includes: a first structure comprising a first wall extending in the Y direction from the second end to the first end; and a second structure comprising a second wall extending in the Y direction from a second end to a first end, wherein the second end of the second wall is permanently joined to the first end of the first wall, wherein an interior of the body is at least partially defined by the first wall and the second wall, the first wall comprises a first metallized material, and the second wall comprises a second metallized material, the second metallized material having a different thermal conductivity than the first metallized material, and wherein The interior of the body is configured to be fluidly connected to a target supply system of the extreme ultraviolet (EUV) light source. 2 . The device of claim 1 , wherein the first end of the first wall and the second end of the second wall are permanently joined at a brazed joint. 3 . The apparatus of claim 1 , wherein the first metallization material comprises molybdenum (Mo) and the second metallization material comprises stainless steel.

4. The apparatus according to claim 1, further comprising: A temperature control system is configured to control the temperature of at least one of the first wall and the second wall.

5. The apparatus of claim 4, wherein the temperature control system comprises: a heating system configured to be thermally coupled to the first wall; as well as A cooling system is configured to be thermally coupled to the second wall, wherein the thermal conductivity of the second metallization material is lower than the thermal conductivity of the first metallization material.

6. The apparatus of claim 1 , wherein the thermal conductivity of the second metallization material is lower than the thermal conductivity of the first metallization material, the first end of the first wall is brazed to the second end of the second wall, and the apparatus further comprises: an O-ring at the first end of the second wall; as well as A removable cover is configured to be retained at the O-ring.

7. The apparatus of claim 1 , wherein the thermal conductivity of the second metallization material is lower than the thermal conductivity of the first metallization material, the first end of the first wall is brazed to the second end of the second wall, and the apparatus further comprises: At least one port extends from the second wall, the at least one port comprising the second metallization material.

8. The apparatus of claim 7, wherein the second metallization material comprises stainless steel.

9. The device of claim 1, wherein the first metallization material comprises a first coefficient of thermal expansion and the second metallization material comprises a second coefficient of thermal expansion.

10. The device of claim 1, wherein an outer side of the first wall is permanently joined to an inner side of the second wall.

11. The device of claim 1 , wherein the body further comprises: a third structure comprising a third wall, the third wall comprising an inner surface and an outer surface; as well as wherein the inner surface of the third wall is permanently bonded to the outer surface of the second wall, and the third wall comprises the second metallization material.

12. The apparatus according to claim 11, further comprising: A temperature control system is configured to control a temperature of at least one of the first wall, the second wall, and the third wall, and wherein the thermal conductivity of the second metallization material is lower than the thermal conductivity of the first metallization material.

13. The apparatus of claim 12, wherein the temperature control system comprises: a heating system configured to be thermally coupled to the first wall; as well as A cooling system is configured to be thermally coupled to the second wall and the third wall, wherein the third wall is between the second wall and the cooling system.

14. The apparatus of claim 1, wherein the apparatus is a target material reservoir configured to hold a target material in the interior of the body, the target material emitting EUV light when in a plasma state.

15. The device of claim 1, wherein the device is a connection assembly, the first structure includes at least a first port, the second structure includes at least a second port, and the first port and the second port are in fluid communication with each other.

16. The apparatus of claim 15, wherein the apparatus is configured to provide a fluid path between an external device coupled to the second port and a reservoir coupled to the first port.

17. An extreme ultraviolet (EUV) light source, comprising: Target supply system, including: a droplet generator configured to generate a target stream, wherein the target comprises a target material that emits EUV light when in a plasma state; and at least one device comprising an interior region configured to be fluidically coupled to the droplet generator, the device comprising: a first structure comprising a first wall extending in the Y direction from the second end to the first end; and a second structure comprising a second wall extending in the Y-direction from a second end to a first end, wherein the second end of the second wall is permanently joined to the first end of the first wall, wherein the interior region is at least partially defined by the first wall and the second wall, the first wall comprises a first metallized material, and the second wall comprises a second metallized material having a different thermal conductivity than the first metallized material; and A container is configured to receive the target from the droplet generator.

18. The extreme ultraviolet (EUV) light source of claim 17, further comprising a light source configured to generate light pulses having energy sufficient to convert at least some of the target material in a target into a plasma state in which the target material emits EUV light.

19. The extreme ultraviolet (EUV) light source of claim 17, wherein the at least one device is a target material reservoir configured to retain the target material in the interior region.

20. The extreme ultraviolet (EUV) light source of claim 19, wherein the target supply system further comprises at least one valve configured to fluidically connect or disconnect the interior region of the target material reservoir from the droplet generator.

21. The extreme ultraviolet (EUV) light source of claim 17, wherein the at least one device is a connection component, the first structure includes at least a first port, the second structure includes at least a second port, and the first port and the second port are in fluid communication with each other.

22. The extreme ultraviolet (EUV) light source of claim 21 , wherein the target supply system further comprises: an external device coupled to the second port; as well as a reservoir coupled to the first port, wherein the reservoir is configured to hold the target material in an internal cavity and is fluidly coupled to the droplet generator; as well as Wherein the connection assembly is configured to provide a fluid path between the external device and the reservoir.

23. The extreme ultraviolet (EUV) light source according to claim 22, wherein the external equipment is a vacuum system or a gas supply system.

24. A target supply system for an EUV light source, the target supply system comprising: a droplet generator configured to generate a target stream, wherein the target comprises a target material that emits EUV light when in a plasma state; as well as at least one device comprising an interior region configured to be fluidically coupled to the droplet generator, the device comprising: a first structure comprising a first wall extending in the Y direction from the second end to the first end; as well as a second structure comprising a second wall extending in the Y direction from a second end to a first end, wherein the second end of the second wall is permanently joined to the first end of the first wall, wherein the interior region is at least partially defined by the first wall and the second wall, the first wall comprises a first metallization material, and the second wall comprises a second metallization material having a different thermal conductivity than the first metallization material.

25. The target supply system of claim 24, wherein the at least one device is a target material reservoir configured to retain the target material within the interior region.

26. The target supply system of claim 24, further comprising at least one valve configured to fluidly connect or disconnect the interior region of the at least one device from the droplet generator.

27. The targeted supply system of claim 24, wherein the at least one device is a connection assembly, the first structure includes at least a first port, the second structure includes at least a second port, and the first port and the second port are in fluid communication with each other.

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