Freezing valve in target material generating device

Abstract

A cryogenic valve includes a valve sleeve defining an axial bore in fluid communication with a first fluid port; and a valve body defining an axial opening between an axially closed end received within the axial bore and an axially open end in fluid communication with the second fluid port. The valve body includes one or more through holes formed in a longitudinal section of the valve body at the axially closed end, each through hole fluidly coupling the axial opening and the axial bore of the valve sleeve.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 63 / 343,638, filed on May 19, 2022, entitled FREEZE VALVE IN A TARGETMATERIAL GENERATOR, which is incorporated herein by reference in its entirety. Technical Field

[0003] The disclosed subject matter relates to a cryovial for use in a target material generating apparatus. Background Art

[0004] Extreme ultraviolet (EUV) light (e.g., electromagnetic radiation having a wavelength of 100 nanometers (nm) or less (sometimes also referred to as soft x-rays), and including light having a wavelength of, for example, 20 nm or less, between 5 and 20 nm, or between 13 and 14 nm) can be used in a photolithography process to create extremely small features in or on a substrate (e.g., a silicon wafer) by initiating polymerization in a resist layer. Methods for generating EUV light include, but are not limited to, changing the physical state of a source material to a plasma state. The source material includes a compound or element, such as xenon, lithium, or tin, whose emission lines are in the EUV range. In one such method, often referred to as laser produced plasma ("LPP"), the desired plasma is generated by irradiating the source material (e.g., in the form of droplets, streams, or clusters of source 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, such as a vacuum chamber, and monitored using various types of metrology equipment. Source materials (such as xenon, lithium, or tin) that emit in the EUV range when in a plasma state are often referred to as target materials because they are directed and irradiated by the drive laser. The droplets, streams or clusters of target material are generated by a target material generation device within which the target material is transported. Summary of the invention

[0005] In some general aspects, a cryovalve includes a valve body including a longitudinal section defining an axial opening through which a fluid flows. The valve body defines a plurality of holes, each hole extending from the axial opening and in fluid communication with the axial opening and through the longitudinal section of the valve body, each hole having a diameter smaller than a diameter of the axial opening.

[0006] Implementations may include one or more of the following features. For example, a longitudinal section of the valve body may have a cylindrical shape. Each hole may extend radially between the axial opening and the exterior of the valve body. The valve body may include an axial barrier at the end of the longitudinal section, the axial barrier being configured to retain a solid target material at a temperature below the freezing point of the target material, for example, when pressure is applied along the axial opening. The holes may provide a flow path that enables a gas to flow between the axial opening of the valve body and the first fluid port of the cryovial at a temperature above the freezing point of the target material. The axial barrier may be configured to retain the solid target material at a temperature below the freezing point of the target material and at a pressure greater than 30,000 pounds per square inch (PSI). The holes may be configured to enable the gas to flow at a temperature of at least 10 -5 A conductivity of liters per second (L / s) flows between the axial opening and the first fluid port. The target material may include tin, and the gas may include an inert gas and hydrogen.

[0007] The valve body may be made of a refractory metal. The valve body may be made of molybdenum, tungsten, niobium, rhenium, or an alloy of any of these materials.

[0008] The cryovalve may further include a valve sleeve axially aligned with the valve body, the valve body being received in an axial bore of the valve sleeve. A fluid flow gap may be defined between the valve sleeve and the valve body such that a fluid flow path is formed between the hole of the valve body and the axial bore of the valve sleeve.

[0009] Each of the holes may extend perpendicularly to the axial direction of the axial opening.

[0010] In other general aspects, a cryovalve includes: a valve sleeve defining an axial bore in fluid communication with a first fluid port; and a valve body including a longitudinal segment. The valve body defines an axial opening between an axial closed end received within the axial bore and an axial open end in fluid communication with a second fluid port. The valve body includes one or more through holes formed in the longitudinal segment at the axial closed end, each through hole fluidly coupling the axial opening and the axial bore of the valve sleeve.

[0011] Implementations may include one or more of the following features. For example, the diameter of each of the one or more through holes may be smaller than the diameter of the axial opening. The longitudinal section of the valve body may have a cylindrical shape. The axially closed end may include an axial barrier at the end of the longitudinal section, the axial barrier being configured to retain the solid target material at a temperature below the freezing point of the target material, for example, when pressure is applied along the axial opening. The holes may provide a flow path to allow gas to flow between the axial opening of the valve body and the first fluid port at a temperature above the freezing point of the target material. The axial barrier may be configured to retain the solid target material at a temperature below the freezing point of the target material and at a pressure greater than 30,000 pounds per square inch (PSI). The holes may provide a flow path to allow gas to flow at a temperature of at least 10 -5 A conductivity of liters per second (L / s) flows through the hole. The target material may include tin, and the gas may include an inert gas and hydrogen.

[0012] The valve body and the valve sleeve may be made of a refractory metal. The valve body and the valve sleeve may be made of molybdenum, tungsten, niobium, rhenium or an alloy of any of these materials. The valve sleeve and the valve body may be axially aligned. A fluid flow gap may be defined between the valve sleeve and the valve body so that a fluid flow path is formed between the hole of the valve body and the axial hole of the valve sleeve. Each of these holes may extend perpendicular to the axial direction of the axial opening. The first fluid port and the second fluid port may be axially aligned with the valve body. Each hole may extend radially from the axial opening to the axial hole at the outside of the longitudinal section of the valve body.

[0013] In other general aspects, a method for controlling a fluid includes: cooling a target material within an axial opening of a valve body; once the target material is frozen, preventing the frozen target material from being axially extruded from the valve body when an axial pressure greater than 10,000 PSI is applied to the frozen target material, including blocking the frozen target material at an axial barrier formed at an axially closed end of the valve body; thawing the target material within the axial opening of the valve body; and once the target material is thawed, enabling the fluid to flow between the axial opening of the valve body and a first fluid port through a through hole formed in a longitudinal section of the valve body at the axially closed end.

[0014] Implementations may include one or more of the following features. For example, by supplying pressurized gas through the first fluid port and entering the axial opening through the through hole, a fluid may be enabled to flow between the axial opening of the valve body and the first fluid port through the through hole formed in the longitudinal section. The pressurized gas may push the thawing target material out of the axial opening of the valve body.

[0015] The frozen target material can be prevented from axially flowing out of the valve body by preventing the frozen target material from being axially extruded from the valve body when an axial pressure greater than 30,000 PSI is applied to the frozen target material, including blocking the frozen target material at an axial stop. -5 A conductivity flow of liters per second (L / s) may enable fluid to flow between the axial opening of the valve body and the first fluid port through the through hole.

[0016] In other general aspects, a target material nozzle assembly includes: a nozzle in fluid communication with a reservoir; and a purge cryo valve in fluid communication with a fluid flow path between the nozzle and the reservoir. The purge cryo valve includes: a valve sleeve defining an axial bore in fluid communication with a first fluid port; and a valve body defining an axial opening between an axial closed end received within the axial bore and an axial open end in fluid communication with a second fluid port, the second fluid port being in fluid communication with the fluid flow path between the nozzle and the reservoir. The valve body includes one or more through holes formed in a longitudinal section of the valve body at the axial closed end, each through hole fluidly coupling the axial opening and the first fluid port. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1A is a block diagram of a cryo valve including a valve body having an axially closed end received in a valve sleeve;

[0018] Figure 1B yes Figure 1A An exploded perspective view of a freezing valve in FIG.

[0019] Figure 1C yes Figure 1B A close-up perspective view of the axial closed end of the valve body showing details of the through hole;

[0020] Figure 2A is a block diagram showing the valve sleeve and the axial closed end of the valve body of the freezing valve when the freezing valve of FIG. 1 is in a closed state;

[0021] Figure 2B is a block diagram showing the valve sleeve and the axially closed end of the valve body of the freezing valve when the freezing valve of FIG. 1 is in an open state;

[0022] Figure 3 It shows Figures 1A to 1C Schematic diagram of a cryo valve in a target material nozzle assembly;

[0023] Figure 4A yes Figures 1A to 1C A side cross-sectional view of an implementation of a freezing valve;

[0024] Figure 4B yes Figure 4AA close-up of the axially closed end of the cryo valve;

[0025] Figure 4C and 4D It is along Figure 4B Axial cross-sections of the cryo valve taken along corresponding lines 4C-4C and 4D-4D;

[0026] Figure 5 is shown for use Figures 1A to 4D A flow chart of the process of controlling a fluid by any cryogenic valve;

[0027] Figures 6A to 6E yes Figures 1A to 1C The refrigeration valve is Figure 5 side cross-sectional views at various steps during the process;

[0028] Figures 7A to 7F It shows that Figure 5 During the process Figures 6A to 6E A schematic diagram of a cryo valve in a target material nozzle assembly; and

[0029] Figure 8 FIG. 1 is a diagram showing a target generation device integrated in a target generation device for supplying a target to an EUV light source. Figure 3 Schematic block diagram of an implementation of a target material nozzle assembly. DETAILED DESCRIPTION

[0030] Reference Figure 1A and 1B , the freezing valve 100 includes a valve sleeve 105 and a valve body 120. The valve sleeve 105 defines an axial hole 106 in fluid communication with the first fluid port 101A. The valve body 120 defines an axial opening 121 between an axial closed end 122A received in the axial hole 106 and an axial open end 122B in fluid communication with the second fluid port 101B. The valve body 120 includes an axial blocking portion 123A located at the axial closed end 122A and a longitudinal section 123B extending axially from the axial blocking portion 123A along the +Z direction, and the axial opening 121 is within the longitudinal section 123B. A gap 130 is formed between the valve sleeve 105 and the axial closed end 122A. The axial opening 121 extends along an axial direction parallel to the Z axis. The valve body 120 includes one or more through holes 125-i formed in the axial closed end 122A and extending through the longitudinal section 123B, where i is a set of numbers 1, 2, ..., I, and I is a positive integer. Each through hole 125-i extends along a hole axis that is located in a plane that is not parallel to the Z axis. For example, each through hole 125-i can have a hole axis in the XY plane that is perpendicular to the Z axis and is located in the XY plane. Figure 1A and 1BIn the illustrated embodiment, the through-holes 125-i also extend radially. In other embodiments, the through-holes may have a hole axis in the XY plane and perpendicular to the Z axis, but may extend in a direction angled relative to the radial direction. At certain times during operation, the through-holes 125-i serve as fluid flow channels or conduits.

[0031] exist Figure 1A In FIG. 1 , six through holes 125-1, 125-2, 125-3, 125-4, 125-5, and 125-6 are shown. However, less than six or more than six through holes may be formed in the valve body 120. For example, Figure 1B and 1C There are 18 through holes, namely, 125-1, 125-2, 125-3, 125-4, 125-5, 125-6, 125-7, 125-8, 125-9, 125-10, 125-11, 125-12, 125-13, 125-14, 125-15, 125-16, 125-17, 125-18. Figure 1C Each through hole 125-i provides a flow path for fluid between the axial opening 121 and the gap 130 formed between the valve sleeve 105 and the valve body 120. Moreover, since the valve body 120 is sealed to the open end 103 of the valve sleeve 105 using a sealing element 104 (such as an annular gasket), any fluid flowing within the axial bore 106 is in fluid communication with the first fluid port 101A because the fluid is prevented from passing through the sealing element 104. In some implementations, such as Figure 1A As shown, the annular gasket 104 can be located between the outer cylindrical surface 127 of the longitudinal section 123B of the valve body 120 and the inner cylindrical surface 129 of the valve sleeve 105. In other implementations, such as Figure 1B As shown, the annular gasket 104 may be located between a radial flange 126 (formed on an outer cylindrical surface 127 of the longitudinal section 123B of the valve body 120 ) and an outer radial surface 128 of the valve sleeve 105 .

[0032] The cryovial 100 is configured to perform two functions. When the valve 100 is in a closed state, a first function occurs, wherein the cryovial 100 holds or maintains a target material. The cryovial 100 can perform the first function after it is sufficiently cooled such that the target material within the cryovial 100 freezes and becomes a solid target material. This solid target material acts as a plug, preventing fluid from flowing through the cryovial 100. When the cryovial 100 is in an open state, a second function occurs, wherein the cryovial 100 allows a fluid to flow, which fluid can be a gas, a liquid, or a combination of a gas and a liquid. The cryovial 100 can perform the second function after it is substantially heated enough to thaw the target material within the cryovial 100 and become a fluid (such as a liquid) target material.

[0033] Reference Figure 2A , when the cryovial 100 is closed, and therefore during the execution of the first function, wherein the target material within the cryovial 100 is a solid target material 207S, the cryovial 100 needs to be able to retain the solid target material 207S within the axial opening 121 at an expected operating pressure P applied along the -Z direction. Typically, the pressure P that can be applied along the -Z direction can reach a maximum value Pmax of 8,000 pounds per square inch (PSI) before the solid target material begins to squeeze out of the cryovial along the -Z direction. On the other hand, the cryovial 100 is designed such that when closed (and during the execution of the first function), the solid target material 207S within the axial opening 121 will not squeeze out of the cryovial 100 along the -Z direction even at a pressure reaching a maximum value Pmax of 31,000 PSI. Instead, the only path that the solid target material 207S can squeeze out is through the holes 125-i, and thus the solid target material can only squeeze out of the axial opening 121 in a direction that is not parallel to the -Z direction. Therefore, if the holes 125-i are arranged to extend radially, the vector of the solid target material 207S extruded from the axial opening 121 is along the XY plane, which is orthogonal to the vector of the pressure P applied to the solid target material 207S, which is along the -Z direction. The pressure of the solid target material 207S in the axial opening 121 extruded from the cryovalve 100 is referred to as the "punch pressure". Since the extrusion vector is orthogonal to the pressure P vector (in this example), the punch pressure of the cryovalve 100 is much greater than that of existing cryovals, and can be at least 10,000 PSI, at least 20,000 PSI, at least 30,000 PSI, or at least 31,000 PSI.

[0034] On the other hand, referring to Figure 2B, when the cryovalve 100 is open, and therefore during the performance of the second function, wherein all of the target material within the cryovalve 100 is liquid, the cryovalve 200 needs to be able to direct the fluid 208F through the axial opening 121 at an acceptable rate. The rate at which the fluid 208F is directed through the axial opening 121 is referred to as the "conductivity" of the cryovalve 100. The fluid 208F may include the target material in fluid or liquid form (fluid target material). The fluid 208F may also include fluid materials other than the target material, such as a purge gas. The cryovalve 100 is designed such that even though the ram pressure of the cryovalve 100 may be 31,000 PSI (during the performance of the first function), the conductivity of any fluid 203F passing through the cryovalve 100 (during the performance of the second function) is not adversely affected by the design of the cryovalve 100, which enables the ram pressure to be increased during the performance of the first function. By increasing the number of through holes 125-i, the conductivity of the fluid 208F passing through the cryovial 100 (particularly through the axial opening 121) can be increased, since the conductivity is linearly related to the number of holes 125-i. In fact, the cryovial 100 can be designed such that the conductivity of the fluid 208F passing through the cryovial 100 during the performance of the second function is increased (e.g., 10 times, 20 times, or even 30 times) compared to a prior art cryovial lacking through holes 125-i.

[0035] As discussed in more detail below, the increase in ram pressure and the maintenance (and improvement) of the electrical conductivity of the cryovalve 100 is the result of axially closing one end of the valve body 120 (axially closed end 122A) and including a through hole 125-i in the longitudinal section 123B near or at the axially closed end 122A.

[0036] Refer again Figure 2A , under pressure P, the solid target material 207S in the axial opening 121 is pushed toward the inner wall 224A of the axial blocking portion 123A, and also enters the through-hole 125-i in the longitudinal section 123B. However, the solid target material 207S cannot completely pass through the through-hole 125-i. The reason for this situation is due to the geometric configuration and number of the through-holes 125-i. In particular, the through-holes 125-i extend axially in a direction that is not parallel to the axial direction of the axial opening 121 (parallel to the Z axis). The non-parallel direction can be a direction perpendicular to, for example, the Z axis (at an angle of 90° to the Z axis), or it can be at an angle between 0 and 90° to the Z axis. Moreover, as Figure 1A As shown in detail, the diameter D of each hole 125 - i in the hole 125 - i 125 (taken along a direction perpendicular to the axial direction of each hole 125 - i ) is the diameter D of the axial opening 121 121(taken along the direction perpendicular to the Z axis). On the other hand, the pressure P applied to the solid target material 207S is applied along the axial direction (-Z direction). Due to these geometric constraints, the solid target material 207S pushed along the -Z direction faces greater friction in the cryovial 100. Therefore, in response to the pressure P applied along the -Z direction, a greater amount of force is applied to the solid target material 207S along the +Z direction. Therefore, the punch pressure that will force the solid target material 207S to flow all the way through the holes 125-i, into the axial hole 106 (in the gap between the valve body 120 and the valve sleeve 105) and through the first fluid port 101A is much greater (e.g., twice as large, three times as large, or even four times as large) than the punch pressure that only forces the solid target material 207S through the opening of the axial open end of the valve body 120 in the existing cryovial. Therefore, the solid target material 207S remains in the axial opening 121 (or a small amount is squeezed into one or more holes 125-i to be recaptured during the performance of the second function).

[0037] Reference Figure 2B , the cryovalve 100 is shown in an open state, during which a fluid 208F can flow through the axial opening 121. The fluid 208F can be or include a gas 209G, such as from a gas system (such as Figure 3 100). The purge or forming gas may be a gas that is non-reactive with the target material and the materials of the valve body 120 and the valve sleeve 108. The purge or forming gas may include, for example, inert gases such as argon and hydrogen. The fluid 208F may also include the target material in liquid form held within the cryovalve 100. The fluid 208F may be supplied from an external gas system ( Figure 3 ) is directed through the first fluid port 101A, through the annular gap 130 ( Figure 1A , 2A and 2B), i.e., a portion of the axial bore 106 defined between the valve sleeve 105 and the valve body 120, through the through-holes 125-i of the longitudinal section 123B, and then through the axial opening in the +Z direction. The conductivity of the fluid 208F from the first fluid port 101A and through the axial opening 121 depends on the total cross-sectional area of ​​all through-holes 125-i and the total number of through-holes 125-i. As an example, if the pressure applied to the purge or forming gas is in a molecular flow regime (i.e., 10 -6 PSI level) and the cryo valve 100 is at room temperature, and if the diameter D of the axial opening 121 is 121 2.5 mm and has 30 through holes 125 - i , wherein the diameter D of each through hole 125 - i 125 is 0.5 mm, then the conductivity through the freezing valve 100 can be about 7×10 -5Under similar conditions, the conductivity of a cryovalve of equal size lacking the through holes 125-i in the valve body 120 disposed within the valve sleeve 105 may be approximately 3×10 -6 L / s.

[0038] Refer again Figure 1B In the illustrated implementation, the valve body 120 (including the longitudinal section 123B) and the valve sleeve 105 have a cylindrical shape such that the axes of each of the cylinders are aligned with each other and are also parallel to the Z axis. The valve body 120 and the valve sleeve 105 are sufficiently rigid to withstand the pressure applied to the cryovial 100 (such as the pressure P applied to the solid target material 207S or the pressure of the gas 209G). The valve body 120 and the valve sleeve 105 are made of a material that is compatible with (and non-reactive with) the target material that contacts the valve body 120 and the valve sleeve 105. For example, referring to Figure 3 If the cryovalve 100 is used in the target material nozzle assembly 340, it is configured to supply the target (e.g. Figure 8 As shown in FIG. 3 ), the target material 342 may include tin or a tin alloy. For this application, the valve body 120 and the valve sleeve 105 should not react with the tin of the target material 342. In this application, the valve body 120 and the valve sleeve 105 may be made of a refractory metal such as molybdenum, tungsten, niobium, rhenium, or an alloy of these metals.

[0039] See also Figure 3 , the implementation 300 of the cryovial 100 is used for a target material nozzle assembly 340. The target material nozzle assembly 340 includes a nozzle 344 in fluid communication with a reservoir 346. The reservoir 346 is configured to contain a liquid target material 342. A fluid flow path 348 is formed between the reservoir 346 and the nozzle 344, so that the liquid target material 342 stored in the reservoir 346 is supplied to the nozzle 344. The fluid flow path 348 may include components (such as additional valves and reservoirs) for additional control of the liquid target material 342. The nozzle 344 may be made of a capillary 347 that generally extends in a longitudinal direction and defines an opening 345. The opening 345 is located at the end of the capillary 347 and the opening 345. The capillary 347 may be made of glass in the form of, for example, fused quartz, borosilicate, aluminosilicate, or quartz. The liquid target material 342 flows through the capillary 347 and is ejected through the opening 345. When the pressure applied at the reservoir 346 is greater than a certain pressure (such as the Laplace pressure), the liquid target material 342 leaves the opening 345 as a target stream (as shown below in Figure 7C ).

[0040] The cryovalve 300 is a purge cryovalve that is in fluid communication with a fluid flow path 348 between a nozzle 344 and a reservoir 346. The cryovalve 300 is similar in design to the cryovalve 100 and includes a first fluid port 301A and a second fluid port 301B. The first fluid port 301A is in fluid communication with a gas system 311, while the second fluid port 301B is in fluid communication with the fluid flow path 348.

[0041] The cryovial 300 also includes a temperature control device 310 configured to control the temperature at which the cryovial 300 operates, thereby opening and closing the cryovial 300, as discussed in more detail below. For example, the temperature control device 310 can be a cartridge heater in thermal communication with one or more of the valve body 320 and the valve sleeve 305 of the cryovial 300. If the temperature control device 310 maintains the temperature of the valve sleeve 305 and the valve body 320 substantially below the melting point of the liquid target material 342, any liquid target material 342 within the axial opening 321 of the cryovial 300 will solidify (change state from liquid to solid), and such solid target material will block the axial opening 321, thereby preventing any fluid (such as the liquid target material 342 or gas from the gas system 311) from passing through the cryovial 300. If the temperature control device 310 maintains the temperature of the valve sleeve 305 and the valve body 320 above the melting point of the liquid target material 342, then any solid target material within the axial opening 321 (and within the through hole 325) will melt to form liquid target material 342, and then this liquid target material 342 (and the gas from the gas system 311) will flow freely through the cryovial 300.

[0042] Reference Figures 4A to 4D, shows an implementation 400 of the cryo valve 100. Like the cryo valve 100, the cryo valve 400 includes a valve sleeve 405 and a valve body 420. The valve sleeve 405 defines an axial bore 406, which is in fluid communication with the first fluid port 401A. The valve body 420 defines an axial opening 421 between an axial closed end 422A received in the axial bore 406 and an axial open end 422B in fluid communication with the second fluid port 401B. Both the valve body 420 and the valve sleeve 405 are radially symmetrical and therefore cylindrical in shape. The valve body 420 includes an axial stop 423A located at the axial closed end 422A and a longitudinal section 423B extending axially from the axial stop 423A along the +Z direction, and the axial opening 421 is within the longitudinal section 423B. A gap 430 is formed between the valve sleeve 405 and the axial closed end 422A. The axial opening 421 extends along an axial direction parallel to the Z axis. The valve body 420 includes one or more through holes 425-i formed in the longitudinal section 423B of the axial closed end 422A, where i is a set of numbers 1, 2, ..., I, and I is a positive integer. Each through hole 425-i extends along a hole axis, which is located in a plane that is not parallel to the Z axis. In this implementation, each through hole 425-i has a hole axis in the XY plane, which is perpendicular to the Z axis. In this implementation, there are a total of 30 through holes (i is a set of numbers 1, 2, ..., 30 and I is 30). The six radially extending holes are arranged at different angles relative to each other in each of the five XY planes that cut the valve body 420.

[0043] The sealing element 404 is fixed between a radial flange 426 of the valve body 420 (e.g., around the longitudinal section 423B of the valve body 420) and an outer radial surface 428 of the valve sleeve 405. The sealing element 404 can be a gasket. The valve body 420 can include an outer connecting surface 413, and the valve sleeve 405 can include an inner connecting surface 414, which are arranged adjacent to each other when the valve 400 is fully assembled. For example, the outer connecting surface 413 and the inner connecting surface 414 can include mating threads. During assembly of the cryovalve 400, the gasket 404 is positioned at the outer radial surface 428 of the valve sleeve 405; the valve body 420 (particularly the axial closed end 422A) is inserted into the axial hole 406 along the -Z direction; when the inner connection surface 414 contacts the outer connection surface 413, the valve body 420 is rotated relative to the valve sleeve 405, thereby screwing the valve body 420 into the valve sleeve 405; and the valve body 420 is rotated relative to the valve sleeve 405 while moving along the -Z direction until the gasket 404 is pressed and forms a seal, preventing any material from leaving the gap 430 between the valve sleeve 405 and the valve body 420. In some implementations, the outer connection surface 413 can be formed on a mating element 431 that is fixed to the outer surface of the longitudinal section 423B.

[0044] Reference Figure 5 , process 550 is performed by the cryovalve 600 (which may be cryovalve 100, 300, or 400) used in the target material nozzle assembly 740. The steps of process 550 are referred to as Figures 6A to 6E 7A to 7F are shown with the cryovial 600 and the target material nozzle assembly 740. Features of the cryovial 600, such as the gap 630 and the through-holes 625-i, are exaggerated and not drawn to scale in order to illustrate the operation. Also, only four through-holes 625-i are shown, but as mentioned above, fewer than four or more than four through-holes may be formed in the body 620 of the cryovial 600. As discussed above, the number of through-holes 625-i affects the conductivity through the cryovial 600. At various times in the process 550, the target material is in solid form and Fig. 6A In the process 550, the target material is designated as a solid target material 607S. At other times in the process 550, the target material is in the form of a fluid (such as a liquid) and Figures 6A to 7F is designated as liquid target material 607L. Figures 6A to 7F In FIG. 6 , the purge or forming gas is designated as gas 608G.

[0045] Process 550 begins by cooling a target material (551) present in an axial opening 621 of a valve body 620. Fig. 7A As shown, at the start of step 551, the target material present in the axial opening 621 may include a liquid target material 607L. At the start of step 551, the liquid target material 607L has entered the axial opening 621 through the second fluid port 601B, which is in fluid communication with the fluid flow path 748 formed between the reservoir 746 and the nozzle 744. At this time, the gas system 711 can additionally apply a pressure Pp along the +Z direction to prevent the liquid target material 607L in the axial opening 621 from leaking through the hole 625-i. At the start of step 551, the nozzle 744 is frozen, which means that the nozzle 744 is maintained at a temperature below the freezing point of the target material, so only the solid target material 607S is present in the nozzle 744, and the nozzle 744 is effectively closed. Therefore, the liquid target material 607L does not flow to the nozzle 744.

[0046] In some implementations, or to accelerate the cooling process, the liquid target material 607L can be actively cooled (551) by the temperature control device 610. In other implementations where the melting point of the liquid target material 607L is above the ambient temperature (such as tin, which has a melting point of approximately 232°C), the liquid target material 607L can be passively cooled (551) by simply removing the heat source applied to the valve body 620 and the valve sleeve 605 (e.g., by turning off the temperature control device 610).

[0047] Once the liquid target material 607L within the axial opening 621 of the cryovial 600 is completely frozen (552), the cryovial 600 can be operated in a closed state, such as Figure 6B and 7B In the closed state, the cryo valve 600 holds or maintains the solid target material 607S. Specifically, due to the design of the cryo valve 600, even when the cryo valve 600 is opened along the -Z direction ( Figure 6B ) applies pressure P, the solid target material 607S will not be squeezed out axially from the valve body 620, and this pressure P is as high as 31000 PSI (553). In particular, since the solid target material 607S is blocked by the axial blocking portion 123A ( Figure 1A ) blocks, thereby preventing the solid target material 607S from moving along the -Z direction ( Figure 6B ) and passes through the first fluid port 601A. Moreover, when the solid target material 607S attempts to extrude through the through hole 625, it faces greater friction because, as discussed above, the through hole 625 extends in a direction that is not parallel (e.g., may be orthogonal) to the direction in which the pressure P is applied. Therefore, even if some of the solid target material 607S enters the through hole 625-i, as long as the pressure P remains below the punch pressure (as discussed above, the punch pressure is as high as 31,000 PSI), the solid target material 607S will not advance very far and will not reach the gap 630.

[0048] At this point, in process 550, and with reference to Figure 7C , since the freeze valve 600 is closed, the target material nozzle assembly 740 can be operated in a supply mode, when the nozzle 744 is not frozen (so that the solid target material 607S in the nozzle 744 is thawed), and the liquid target material 607L (stored in the reservoir 746) can be supplied to the nozzle 744. Due to the geometry of the nozzle 744, when the pressure P is increased to a value greater than the predetermined minimum nozzle pressure, the liquid target material 607L exits through the nozzle 744 as a stream 760 of target 762. For example, the predetermined minimum nozzle pressure can be approximately 100 PSI.

[0049] When the nozzle 744 needs to be repaired or replaced, a purge command is received (554). At this point, the gas system 711, the cryovalve 600, and the nozzle 744 work together to purge any liquid target material 607L from the fluid flow path 748 between the nozzle 744 and the reservoir 746. To do this, the nozzle 744 is frozen (as discussed above), and then the cryovalve 600 needs to be closed (as discussed above). Figure 6B The temperature control device 610 begins to actively warm the solid target material 607S in the cryo valve 600 (555). Figure 6C and 7DThis active warming is shown while some of the solid target material 607S has melted into the liquid target material 607L. During this time, the pressure P applied to the liquid target material 607L is reduced, and because the nozzle 744 is frozen, the liquid target material 607L is no longer actively supplied to the nozzle 744. As a result, the nozzle 744 stops producing a stream 760 of the target 762. However, some of the liquid target material 607L may remain in the fluid flow path 748 between the nozzle 744 and the reservoir 746.

[0050] Once all solid target material 607S is thawed (556), fluid can flow between the axial opening 621 of the valve body 620 and the first fluid port 601A through the radially extending holes 625-i in the valve body 620 (557). As the purge is being performed, the gas system 711 flows through the first fluid port 601A of the cryo valve 600 in the +Z direction ( Fig.6D ) supplies a purge or forming gas 608G (at a pressure Pp). First, the gas 608G enters the first fluid port 601A and the gap 630, and then it enters the through hole 625-i, as shown in FIG. Fig.6D As shown in detail and as a whole Fig. 7E As shown. The gas 608G pushes the liquid target material 607L out of the cryovial 600 and also out of the fluid flow path 748. The gas 608G is pushed through the cryovial 600 at a conductivity that increases with the number of through holes 625-i in the valve body 620. Eventually, all of the liquid target material 607L within the cryovial 600 and in the fluid flow path 748 is pushed back into the reservoir 746 by the gas 608G. And, as the conductivity of the gas 608G through the cryovial 600 is higher, this moment can occur faster.

[0051] Fig. 6E and 7F The status of the cryovalve 600 and the target material nozzle assembly 740 is shown when the purge is complete (558). At this point, since the purge is complete, the nozzle 744 can be serviced or removed (558).

[0052] Process 550 may also include the additional steps of determining whether the repair or replacement of nozzle 744 is complete and receiving instructions to operate nozzle 744 under normal operating conditions. Fig. 6A and 7A As shown, liquid target material 607L can be resupplied from reservoir 746 to fluid flow path 748 and valve body 620 of cryovial 600 .

[0053] Reference Figure 8, the target material nozzle assembly 740 can be integrated into a target generation device 870, which includes additional fluid flow paths and additional reservoirs in addition to other fluid regulating devices (or valves). The target generation device 870 can also include a filling system configured to receive solid matter including the target material. An example of such a target generation device 870 is shown in WO2020 / 187617, which is incorporated herein by reference in its entirety.

[0054] The target generation device 870 supplies the liquid target material 607L to the external system 872 in the form of a stream 760 of targets 762. If the system 872 is an EUV light source, each target 762 is delivered to a plasma formation location 873 in a vacuum chamber 874. The plasma formation location 873 may receive at least one light beam 875 (which may be a pulsed light beam) generated by an optical source 875 and delivered to the vacuum chamber 874 via an optical path 876. The interaction between the pulses of the light beam 875 and the target material in the target 762 within the plasma formation location 873 produces a plasma that emits EUV light 877, which is collected 878 and supplied to a lithography exposure device 879. In this example, the liquid target material 607L may be any material that emits EUV light 877 in a plasma state. For example, the liquid target material 607L may include water, tin, lithium, and / or xenon.

[0055] Other implementations are within the scope of the following claims. For example, if the fluid target material 607L is or includes water, then the valve body 620 and valve sleeve 605 can be made of materials such as refractory metals (as discussed above) or materials such as stainless steel, plastic, or even wood. The material selection of the valve body 620 and valve sleeve 605 also depends on the operating pressure applied to the cryovalve 600 and the manufacturing cost and method.

[0056] The implementation can be further described using the following clauses.

[0057] 1. A freezing valve, comprising:

[0058] a valve body including a longitudinal section defining an axial opening through which fluid flows;

[0059] The valve body defines a plurality of bores, each bore extending from and in fluid communication with the axial opening and through a longitudinal section of the valve body, and each bore having a diameter smaller than a diameter of the axial opening.

[0060] 2. A freezing valve according to clause 1, wherein a longitudinal section of the valve body has a cylindrical shape.

[0061] 3. A cryovalve according to clause 1, wherein each hole extends radially from the axial opening to the exterior of the valve body.

[0062] 4. A cryovial according to item 1, wherein the valve body includes an axial barrier at the end of the longitudinal section, the axial barrier being configured to retain a solid target material at a temperature below the freezing point of the target material when pressure is applied, and the hole provides a flow path that enables gas to flow through at a temperature above the freezing point of the target material.

[0063] 5. The cryovial of clause 4, wherein the bore provides fluid communication between the axial opening of the valve body and the first fluid port of the cryovial.

[0064] 6. The cryovial of clause 4, wherein the axial barrier is configured to retain the solid target material at a temperature below a freezing point of the target material and at a pressure greater than 30,000 pounds per square inch (PSI).

[0065] 7. The cryovial of clause 4, wherein the aperture is configured to enable gas to flow between the axial opening and the first fluid port at a conductivity of at least 10-5 liters / second (L / s) at room temperature and in a molecular flow regime.

[0066] 8. The cryovial of clause 4, wherein the target material comprises tin and the gas comprises an inert gas and hydrogen.

[0067] 9. A cryovalve according to clause 1, wherein the valve body comprises a refractory metal.

[0068] 10. A cryovalve according to clause 1, wherein the valve body comprises molybdenum, tungsten, niobium, rhenium or an alloy of any of these materials.

[0069] 11. The cryovalve of clause 1, further comprising a valve sleeve axially aligned with the valve body, the valve body being received in the axial bore of the valve sleeve.

[0070] 12. The cryovalve of clause 11, wherein a fluid flow gap is defined between the valve sleeve and the valve body such that a fluid flow path is formed between the bore of the valve body and the axial bore of the valve sleeve.

[0071] 13. A cryovial according to clause 1, wherein each of the holes extends perpendicular to the axial direction of the axial opening.

[0072] 14. A freezing valve, comprising:

[0073] a valve sleeve defining an axial bore in fluid communication with the first fluid port; and

[0074] A valve body defines an axial opening between an axially closed end received in the axial bore and an axially open end in fluid communication with the second fluid port, wherein the valve body includes one or more through holes formed in a longitudinal section at the axially closed end, each through hole fluidly coupling the axial opening and the axial bore of the valve sleeve.

[0075] 15. A cryovial according to clause 14, wherein the diameter of each of the one or more through holes is smaller than the diameter of the axial opening.

[0076] 16. A freezing valve according to clause 14, wherein a longitudinal section of the valve body has a cylindrical shape.

[0077] 17. A cryovial according to item 14, wherein the axially closed end includes an axial barrier at the end of the longitudinal segment, the axial barrier being configured to retain the solid target material at a temperature below the freezing point of the target material when pressure is applied, and the hole provides a flow path that allows gas to flow through at a temperature above the freezing point of the target material.

[0078] 18. The cryovial of clause 17, wherein the aperture provides fluid communication between the axial opening of the valve body and the first fluid port.

[0079] 19. A cryovalve according to clause 17, wherein the aperture provides a flow path for gas to flow through the aperture at a conductivity of at least 10-5 liters per second (L / s) at room temperature and in a molecular flow regime.

[0080] 20. The cryovial of clause 17, wherein the target material comprises tin and the gas comprises an inert gas and hydrogen.

[0081] 21. The cryovial of clause 14, wherein the axial closed end comprises an axial barrier at the end of the longitudinal segment, the axial barrier being configured to retain the solid target material at a temperature below the freezing point of the target material and at a pressure greater than 30,000 pounds per square inch (PSI).

[0082] 22. A cryovalve according to item 14, wherein the valve body and the valve sleeve comprise a refractory metal.

[0083] 23. A cryovalve according to clause 14, wherein the valve body and the valve sleeve comprise molybdenum, tungsten, niobium, rhenium or an alloy of any of these materials.

[0084] 24. A cryovalve according to clause 14, wherein the valve sleeve and the valve body are axially aligned.

[0085] 25. The cryovalve of clause 24, wherein a fluid flow gap is defined between the valve sleeve and the valve body such that a fluid flow path is formed between the bore of the valve body and the axial bore of the valve sleeve.

[0086] 26. The cryovial of clause 14, wherein the first fluid port and the second fluid port are axially aligned with the valve body.

[0087] 27. A cryovial according to clause 14, wherein each aperture extends radially from an axial opening to an axial bore outside of a longitudinal section of the valve body.

[0088] 28. A cryovial according to clause 14, wherein each of the holes extends perpendicular to the axial direction of the axial opening.

[0089] 29. A method of controlling a fluid, comprising:

[0090] cooling a target material within an axial opening of the valve body;

[0091] Once the target material is frozen, when an axial pressure greater than 10,000 PSI is applied to the frozen target material, preventing the frozen target material from axially extruding from the valve body, including arresting the frozen target material at an axial stop formed at an axially closed end of the valve body;

[0092] thawing the target material within the axial opening of the valve body; and

[0093] Once the target material is thawed, fluid is enabled to flow between the axial opening of the valve body and the first fluid port through an aperture formed in the longitudinal section of the valve body at the axially closed end.

[0094] 30. The method of clause 29, wherein enabling fluid to flow between the axial opening of the valve body and the first fluid port through the aperture formed in the longitudinal segment comprises supplying pressurized gas through the first fluid port and into the axial opening through the aperture.

[0095] 31. A method according to item 30, wherein the pressurized gas pushes the thawed target material out of the axial opening of the valve body.

[0096] 32. The method of clause 29, wherein preventing the frozen target material from axially flowing out of the valve body includes preventing the frozen target material from axially extruding from the valve body when an axial pressure greater than 30,000 PSI is applied to the frozen target material, including blocking the frozen target material at an axial stop.

[0097] 33. The method of clause 29, wherein enabling fluid to flow through the aperture between the axial opening of the valve body and the first fluid port comprises enabling the fluid to flow at a conductivity greater than at least 10-5 liters / second (L / s) at room temperature and in a molecular flow regime.

[0098] 34. A target material nozzle assembly comprising:

[0099] a nozzle in fluid communication with the reservoir; and

[0100] A purge freezing valve is in fluid communication with the fluid flow path between the nozzle and the reservoir, the purge freezing valve comprising:

[0101] a valve sleeve defining an axial bore in fluid communication with the first fluid port; and

[0102] A valve body defines an axial opening between an axial closed end received in the axial bore and an axial open end in fluid communication with a second fluid port, the second fluid port being in fluid communication with a fluid flow path between the nozzle and the reservoir, wherein the valve body includes one or more through holes formed in a longitudinal section of the valve body at the axial closed end, each through hole fluidly coupling the axial opening and the first fluid port.

[0103] Other implementations are within the scope of the following claims.

Claims

1. A freezing valve, comprising: a valve body including a longitudinal section defining an axial opening through which fluid flows; The valve body defines a plurality of holes, each hole extending from and in fluid communication with the axial opening and through the longitudinal section of the valve body, and each hole having a diameter smaller than a diameter of the axial opening. 2 . The freezing valve of claim 1 , wherein the longitudinal section of the valve body has a cylindrical shape.

3. The cryovial of claim 1, wherein each aperture extends radially from the axial opening to an exterior of the valve body.

4. A freezing valve according to claim 1, wherein the valve body includes an axial barrier at the end of the longitudinal section, the axial barrier being configured to retain a solid target material at a temperature below the freezing point of the target material when pressure is applied, and the hole providing a flow path so that a gas can flow through at a temperature above the freezing point of the target material.

5. The cryovial of claim 4, wherein the aperture provides fluid communication between the axial opening of the valve body and a first fluid port of the cryovial.

6. The cryovial of claim 4, wherein the axial barrier is configured to retain the solid target material at a temperature below the freezing point of the target material and a pressure greater than 30,000 pounds per square inch (PSI).

7. The cryovial of claim 4, wherein the aperture is configured to allow the gas to flow at a rate of at least 10 -5 A conductivity of liters per second (L / s) flows between the axial opening and the first fluid port.

8. The cryovial of claim 4, wherein the target material comprises tin and the gas comprises an inert gas and hydrogen.

9. The cryovalve of claim 1, wherein the valve body comprises a refractory metal.

10. The cryovalve of claim 1, wherein the valve body comprises molybdenum, tungsten, niobium, rhenium, or an alloy of any of these materials.

11. The cryovial of claim 1, further comprising a valve sleeve axially aligned with the valve body, the valve body being received within an axial bore of the valve sleeve.

12. The cryovalve of claim 11, wherein a fluid flow gap is defined between the valve sleeve and the valve body such that a fluid flow path is formed between the bore of the valve body and the axial bore of the valve sleeve.

13. The cryovial of claim 1, wherein each of the holes extends perpendicular to the axial direction of the axial opening.

14. A freezing valve, comprising: a valve sleeve defining an axial bore in fluid communication with the first fluid port; as well as A valve body defines an axial opening between an axially closed end received in the axial bore and an axially open end in fluid communication with the second fluid port, wherein the valve body includes one or more through holes formed in a longitudinal section at the axially closed end, each through hole fluidically coupling the axial opening and the axial bore of the valve sleeve.

15. The cryovial of claim 14, wherein a diameter of each of the one or more through holes is smaller than a diameter of the axial opening.

16. The cryovalve of claim 14, wherein the longitudinal section of the valve body has a cylindrical shape.

17. A freezing valve according to claim 14, wherein the axially closed end includes an axial barrier at the end of the longitudinal segment, the axial barrier being configured to retain the solid target material at a temperature below the freezing point of the target material when pressure is applied, and the hole provides a flow path that allows gas to flow at a temperature above the freezing point of the target material.

18. The cryovial of claim 17, wherein the aperture provides fluid communication between the axial opening of the valve body and the first fluid port.

19. The cryovial of claim 17, wherein the aperture provides the flow path for gas to flow at a rate of at least 10 -5 A conductivity of liters per second (L / s) flows through the pores.

20. The cryovial of claim 17, wherein the target material comprises tin and the gas comprises an inert gas and hydrogen.

21. The cryovial of claim 14, wherein the axially closed end comprises an axial barrier at an end of the longitudinal segment, the axial barrier being configured to retain the solid target material at a temperature below the freezing point of the target material and a pressure greater than 30,000 pounds per square inch (PSI).

22. The cryovalve of claim 14, wherein the valve body and the valve sleeve comprise a refractory metal.

23. The cryovalve of claim 14, wherein the valve body and the valve sleeve comprise molybdenum, tungsten, niobium, rhenium, or alloys of any of these materials.

24. The cryovial of claim 14, wherein the valve sleeve and the valve body are axially aligned.

25. The cryovial of claim 24, wherein a fluid flow gap is defined between the valve sleeve and the valve body such that a fluid flow path is formed between the bore of the valve body and the axial bore of the valve sleeve.

26. The cryovial of claim 14, wherein the first fluid port and the second fluid port are axially aligned with the valve body.

27. The cryovial of claim 14, wherein each aperture extends radially from the axial opening to the axial bore on the exterior of the longitudinal section of the valve body.

28. The cryovial of claim 14, wherein each of said holes extends perpendicular to said axial direction of said axial opening.

29. A method of controlling a fluid, comprising: cooling a target material within an axial opening of the valve body; Once the target material is frozen, when an axial pressure greater than 10,000 PSI is applied to the frozen target material, preventing the frozen target material from axially extruding from the valve body, the preventing the frozen target material from axially extruding from the valve body comprising blocking the frozen target material at an axial stop formed at an axially closed end of the valve body; thawing the target material within the axial opening of the valve body; as well as Once the target material is thawed, fluid is enabled to flow between the axial opening of the valve body and a first fluid port through an aperture formed in a longitudinal section of the valve body at the axial closed end.

30. The method of claim 29, wherein enabling the fluid to flow between the axial opening of the valve body and the first fluid port through the aperture formed in the longitudinal segment comprises: Pressurized gas is supplied through the first fluid port and through the bore into the axial opening.

31. The method of claim 30, wherein the pressurized gas pushes thawing target material out of the axial opening of the valve body.

32. The method of claim 29, wherein preventing the cryogenic target material from axially flowing out of the valve body comprises: When the axial pressure greater than 30,000 PSI is applied to the freezing target material, the freezing target material is prevented from axially extruding from the valve body, the preventing the freezing target material from axially extruding from the valve body includes blocking the freezing target material at the axial stopper.

33. The method of claim 29, wherein enabling the fluid to flow between the axial opening of the valve body and the first fluid port through the aperture comprises: The fluid can flow at a rate greater than at least 10 -5 Conductivity flow in liters per second (L / s).

34. A target material nozzle assembly comprising: a nozzle in fluid communication with the reservoir; as well as a purge freezing valve in fluid communication with the fluid flow path between the nozzle and the reservoir, the purge freezing valve comprising: a valve sleeve defining an axial bore in fluid communication with the first fluid port; as well as a valve body defining an axial opening between an axially closed end received in the axial bore and an axially open end in fluid communication with a second fluid port, the second fluid port being in fluid communication with the fluid flow path between the nozzle and the reservoir, wherein the valve body includes one or more through holes formed in a longitudinal section of the valve body at the axially closed end, each through hole fluidly connecting the axial opening and the first fluid port.

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