A liquid drop tin target supply device for extreme ultraviolet light source

Abstract

The present invention provides a liquid droplet tin target supply device for an extreme ultraviolet light source. The present invention includes a device housing and an acoustic generation and propagation device arranged in the device housing. The present invention separates the local heating part of the tin liquid from the acoustic generation device under the condition of ensuring high stability and high efficiency, thereby solving the problem that the acoustic generation device cannot work at high temperatures. The acoustic generation device of the present invention is independently installed inside the tin droplet generation device, which can greatly ensure that the external micro-disturbance is reduced to a minimum. In addition, the replacement of the small hole is very easy and can be completed quickly outside the device. By using this invention, extremely high spatial stability and good high-frequency repeatability of the tin droplets can be achieved, thereby providing a good tin droplet beam source for the LPP light source.

Description

Technical Field

[0001] The invention relates to the field of EUV (Extreme Ultraviolet) light sources, and in particular to a liquid droplet tin target supply device for an EUV light source. Background Art

[0002] The semiconductor manufacturing industry is developing rapidly. At present, the main lithography technology is EUVL (Extreme Ultraviolet Lithography). EUVL technology uses 13.5nm wavelength light in the extreme ultraviolet band as the light source of the lithography machine for chip etching. Since the wavelength of the 13.5nm wavelength light used is very short, EUVL can achieve very high chip etching accuracy. LPP (Laser Produced Plasma) light source is the mainstream EUV light source in the industry. Its principle is that the high-power carbon dioxide laser is focused and interacts with the continuous tin droplets produced by the droplet tin target supply device. The tin droplets are vaporized under the irradiation of the laser and further ionized to emit 13.5nm EUV light. After that, the EUV light is collected by a large-aperture mirror to obtain high-power EUV light. At the current stage, the peak power of the commercial EUV lithography light source at the focus can reach 150W or more. When manufacturing chips, the EUV light source needs to work stably at high frequencies (~kHz level). This requires that the spatial stability of the tin droplets produced by the tin target supply device is extremely high, and the high-frequency repeatability is good. Summary of the invention

[0003] According to the technical problems raised above, a droplet tin target supply device of an extreme ultraviolet light source is provided, aiming to solve the problems of poor spatial stability of the target material and poor repeatability under high frequency in current research. The technical means adopted by the present invention are as follows:

[0004] A droplet tin target supply device for an extreme ultraviolet light source comprises a device shell and an acoustic generation and propagation device arranged in the device shell, the device shell comprises a main shell and a first end cover plate and a second end cover plate arranged thereon, the first end cover plate is integrated with a chamber for storing liquid tin and a small hole cover plate connected to the chamber, the chamber for storing liquid tin is connected with a feed pipe, the small hole cover plate is provided with small holes for tin droplet flow, the first end cover plate is also connected with an integrated pressurizing device and a temperature regulating device, the integrated pressurizing device is used to pressurize the chamber for storing liquid tin to obtain a continuous tin jet flow, the temperature regulating device is used to regulate the temperature of the first end cover plate, the output end of the acoustic generation and propagation device is connected to the chamber for storing liquid tin, and is used to convert the continuous tin jet flow into a stable tin droplet flow, the acoustic generation and propagation device is equipped with an active refrigeration device, and the second end cover plate is provided with a channel for connecting the active refrigeration device.

[0005] Furthermore, the temperature regulating device comprises a heating rod and a temperature probe, and the voltage at both ends of each heating rod is feedback-regulated by reading the temperature at the temperature probe.

[0006] Furthermore, the output end of the acoustic generating and propagating device is connected to the chamber for storing liquid tin on the first end cover plate through a special part, and the special part includes a film and a tail rod. One side of the special part is the first end cover plate, and the other side is the special part cover plate. The output end of the acoustic generating and propagating device is connected to the tail rod of the special part, and the generated acoustic vibration is transmitted to the special part film, thereby driving the tin droplet generating device to produce stable tin droplets.

[0007] Furthermore, a pressure balancing pipeline is integrated on the second end cover plate, and the pressure balancing pipeline is used to balance the pressure on both sides of the film.

[0008] Furthermore, the acoustic generation and propagation device includes a piezoelectric ceramic cap, a piezoelectric ceramic, a piezoelectric ceramic base and an acoustic transmission rod, the output end of the piezoelectric ceramic is connected to the acoustic transmission rod, the piezoelectric ceramic is mounted on the piezoelectric ceramic base, and the piezoelectric ceramic cap is pressed against the piezoelectric ceramic.

[0009] Furthermore, the size, spacing and frequency of the formed tin droplet targets are adjusted based on adjusting the excitation signal of the piezoelectric ceramic.

[0010] Furthermore, the active cooling device includes a cooling first end cover plate, a cooling second end cover plate and a cooling liquid storage chamber. The liquid cooling pipeline is installed on the second end cover plate through a liquid cooling pipeline pressure plate. The output end of the liquid cooling pipeline passes through the piezoelectric ceramic base of the acoustic generation and transmission device, and extends into the cooling liquid storage chamber between the cooling first end cover plate and the cooling second end cover plate. The cooling liquid storage chamber is wrapped around the outside of the acoustic transmission rod of the acoustic generation and transmission device.

[0011] Furthermore, when the extreme ultraviolet light source's droplet tin target supply device is in working state, the main body is in a vacuum environment, and the first end cover plate, the second end cover plate and the main shell all have a preset thickness, which can at least withstand the working pressure in the small hole tin liquid spraying state.

[0012] Furthermore, a support member for heat insulation is provided between the active refrigeration device and the first end cover plate.

[0013] Furthermore, the small hole on the first end cover plate is fixed by fitting and pressing through the small hole cover plate, and is sealed by squeezing the first gasket between the first end cover plate and the small hole cover plate. The first end cover plate has a positioning groove that can cooperate with the small hole cover plate, so that the center hole of the small hole cover plate and the small hole can coincide with each other.

[0014] Compared with the existing tin droplet target material supply device, this device separates the local heating part of the tin liquid from the acoustic generating device while ensuring high stability and high efficiency, thus solving the problem that the acoustic generating device cannot work at high temperatures. In addition, since the acoustic generating device is independently installed inside the tin droplet generating device, it can ensure that the external micro-perturbation is reduced to a minimum to a great extent. In addition, the replacement of the small hole is very easy and can be completed quickly outside the device. By using this invention, extremely high spatial stability and good high-frequency repeatability of the tin droplets can be achieved, thereby providing a good tin droplet beam source for the LPP light source. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. It should be noted that according to the general operation of this industry, the drawings are not necessarily drawn to scale. In fact, the size of the components may be arbitrarily enlarged or reduced for clear description;

[0016] Figure 1 A schematic structural diagram of a liquid droplet tin target supply device for an extreme ultraviolet light source provided by an embodiment of the present invention;

[0017] Figure 2 for Figure 1 Schematic cross-sectional view of , where (a) is one direction and (b) is the other direction.

[0018] Figure 3 for Figure 1 , where (a) is a top view and (b) is a bottom view.

[0019] Figure 4 It is a schematic diagram of the structure at the location of the small hole.

[0020] Figure 5 The utility model relates to a supply tank of a liquid drop tin target supply device of an extreme ultraviolet light source.

[0021] In the figure: 1. first end cover plate; 2. second end cover plate; 3. main shell; 4. acoustic generating device and transmission device; 5. active cooling device; 6. pinhole cover plate; 7. pinhole; 8. tin liquid chamber; 9. special parts (including film and tail rod); 10. special parts cover plate; 11. heating rod; 12. air pressure balance pipeline; 13. liquid cooling pipeline; 14. conductive terminal; 15. piezoelectric ceramic cap; 16. piezoelectric ceramic; 17. piezoelectric ceramic base; 18. acoustic transmission rod; 19. refrigeration second end cover plate; 20. refrigeration liquid storage chamber; 21. refrigeration first end cover plate; 22. support member; 23. pressurized pipeline; 24. liquid cooling pipeline pressure plate. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The following disclosure provides many different embodiments or examples to implement the different features of the present disclosure. The following disclosure blurs the specific examples of each component and its arrangement to simplify the description. Of course, these specific examples are not intended to be limiting. For example, the size of the component is not limited to the scope or value of the present disclosure, but may depend on the process state and / or the desired properties of the device. Furthermore, if the present disclosure describes a first feature formed on or above a second feature, it means that it may include an embodiment in which the first feature and the second feature are in direct contact, and may also include an additional feature formed between the first feature and the second feature, so that the first feature and the second feature may not be in direct contact. For the sake of clarity and simplicity, different features can be arbitrarily drawn in different proportions.

[0024] In addition, spatially related words, such as "above", "above", "higher", "below" and the like, are used to facilitate the description of the relationship between one element or feature and another element or feature in the figure. In addition to the orientations drawn in the drawings, these spatially related words are intended to express different orientations of the device in use or operation. The device may be turned to different orientations, and the spatially related words used herein may also be interpreted in the same manner.

[0025] like Figures 1 to 5As shown, an embodiment of the present invention discloses a droplet tin target supply device of an extreme ultraviolet light source. When the device is working, a vibration excitation is generated by an acoustic generating device, and is transmitted to the tin droplet vibration chamber through an acoustic propagation device, so that the tin jet flow is sharply broken, and a tin droplet target with extremely high spatial stability and good high-frequency repeatability is obtained. Moreover, by changing the excitation waveform of the acoustic generating device, the generated tin droplet target can be frequency modulated. In addition, changing the pressure difference on both sides of the small hole can also adjust the size of the tin droplets and the spacing between the tin droplets.

[0026] Specifically, the present invention includes a device shell and an acoustic generating and propagating device arranged in the device shell, the device shell includes a main shell 3 and a first end cover plate 1 and a second end cover plate 2 arranged thereon, the first end cover plate is integrated with a chamber 8 for storing liquid tin and a small hole cover plate 6 connected to the chamber, the chamber for storing liquid tin is connected with a feeding pipe, the small hole cover plate is provided with small holes for tin droplets to flow, the first end cover plate is also connected with an integrated pressurizing device and a temperature regulating device, the integrated pressurizing device is used to pressurize the chamber for storing liquid tin to obtain a continuous tin jet stream, the temperature regulating device is used to regulate the temperature of the first end cover plate, the output end of the acoustic generating and propagating device 4 is connected to the chamber for storing liquid tin, and is used to convert the continuous tin jet stream into a stable tin drop stream through the acoustic perturbation effect generated, the acoustic generating and propagating device is equipped with an active refrigeration device, and the second end cover plate is provided with a channel for connecting the active refrigeration device 5.

[0027] In some embodiments, the assembly between the main body parts of the present invention is independently installed, and in some embodiments, the main body parts are not independently installed.

[0028] As an optional embodiment, the first end cover plate and the main shell body and the second end cover plate and the main shell body are pressed tightly, and the second gasket and the third gasket between the extruded surfaces are sealed.

[0029] As another optional implementation, the first end cover plate and the main shell are sealed by bonding or welding, as well as the second end cover plate and the main shell are sealed by bonding or welding.

[0030] In this embodiment, the supply and exhaust of the tin storage chamber are arranged through two or more connecting pipelines, and the pipelines and the first end cover plate are sealed and connected by bonding or welding.

[0031] The output end of the acoustic generation and propagation device is connected to the chamber for storing liquid tin on the first end cover plate through a special part 9. The special part includes a film and a tail rod. One side of the special part is the first end cover plate, and the other side is the special part cover plate 10. The output end of the acoustic generation and propagation device is connected to the special part tail rod, and the generated acoustic vibration is transmitted to the special part film, thereby driving the chamber for storing liquid tin to produce stable tin droplets. In this embodiment, the film and the tail rod can be processed as one piece, or they can be connected by bonding or welding. The film material is stainless steel or titanium alloy. The special part cover plate and the first end cover plate are pressed together, and sealed by squeezing the fourth gasket between the special part cover plate and the first end cover plate.

[0032] The temperature regulating device includes a heating rod 11 and a temperature probe, and the voltage at both ends of each heating rod is feedback-regulated by reading the temperature at the temperature probe. In the present embodiment, there are at least two heating rods, which are inserted at different positions of the first end cover plate, especially near the position of the main shell and the position near the small hole. The temperature probe can be installed near the special cover plate, and the voltage at both ends of each heating rod is feedback-regulated by reading the temperature at the temperature probe, so as to ensure that the tin temperature in the chamber of the liquid tin in the first end cover plate is feedback-controlled to reach or exceed the melting point of the tin. The temperature probe can be a thermistor temperature probe or a thermocouple. As an optional embodiment, the distributed heating method through the heating rod 11 can be replaced with other specific heating methods, and the principle is that the tin liquid in the tin liquid chamber 8 is in a molten state.

[0033] The film of the special part 9 is very thin. When the tin liquid is in the spraying state at the small hole 7, it should be noted that the film of the special part 9 is easily crushed by the positive pressure in the tin liquid chamber 8. Therefore, in order to balance the positive pressure on one side of the film, the second end cover plate 2 is connected with a balance pipeline welded thereon, and a small hole is processed on the special part cover plate 10. The air pressure balance pipeline 12 should be connected with the pressurization pipeline 23. This setting method can make the air pressure applied by the balance pipeline 12 and the air pressure applied by the pressurization pipeline 23 reach a balance at both ends of the film of the special part 9. When the pressurization pipeline 23 provides positive pressure in the tin liquid chamber 8, the internal space of the main shell 3 is also under the same positive pressure, which can keep the film from being crushed. In this embodiment, there are two pressurization pipelines 23, one of which can be used when in use, and the other is used as a spare. Furthermore, when it is necessary to discharge the tin liquid inside the chamber, one can be pressurized (at the same time, the air pressure balance pipeline 12 needs to be pressurized), and the other can discharge the tin liquid.

[0034] The acoustic generation and transmission device includes a piezoelectric ceramic cap 15, a piezoelectric ceramic 16, a piezoelectric ceramic base 17 and an acoustic transmission rod 18. The output end of the piezoelectric ceramic is connected to the acoustic transmission rod. The piezoelectric ceramic is mounted on the piezoelectric ceramic base, and the piezoelectric ceramic cap is pressed against the piezoelectric ceramic. The acoustic transmission rod can be made of ceramic, aluminum alloy or polyimide.

[0035] The acoustic excitation signal of the acoustic generating device and the propagating device 4 is generated by the piezoelectric ceramic 16. The excitation voltage of the external piezoelectric ceramic can be adjusted to generate a certain high-frequency vibration (~KHz level, generally from 10KHz to 200KHz, the waveform is such as a sine wave). The acoustic excitation signal of the piezoelectric ceramic 16 should be efficiently transmitted in the direction of the acoustic transmission rod 18, so the piezoelectric ceramic cap 15 needs to press the piezoelectric ceramic 16, and a buffer is added between them to isolate the sound to prevent the acoustic excitation signal of the piezoelectric ceramic 16 from propagating in the direction of the piezoelectric ceramic cap 15. The buffer should have an acoustic shielding effect, and the material selection can consider silicone, rubber, polyimide and other materials. The connection between the piezoelectric ceramic 16 and the acoustic transmission rod 18 can be achieved by bonding or welding. In particular, the acoustic transmission rod 18 must efficiently transmit the acoustic signal and cannot be too heat-conductive. Therefore, ceramics, aluminum alloys, etc. are given priority in materials. The connection between the tail rod of the special part 9 and the acoustic transmission rod 18 can be achieved by bonding or welding. The size, spacing and frequency of the formed tin droplet targets are adjusted based on the excitation signal of the piezoelectric ceramic.

[0036] The active refrigeration device includes a first refrigeration end cover plate 21, a second refrigeration end cover plate 19 and a refrigeration liquid storage chamber 20. The liquid cooling pipeline is installed on the second end cover plate through a liquid cooling pipeline pressure plate 24. The output end of the liquid cooling pipeline passes through the piezoelectric ceramic base of the acoustic generation and propagation device and extends into the refrigeration liquid storage chamber between the first refrigeration end cover plate and the second refrigeration end cover plate. The refrigeration liquid storage chamber is wrapped around the outside of the acoustic transmission rod of the acoustic generation and propagation device. When the first refrigeration end cover plate and the refrigeration liquid storage chamber, the second refrigeration end cover plate and the refrigeration liquid storage chamber, and the second refrigeration end cover plate and the piezoelectric ceramic base are all in a compressed state, the fifth gasket between the extrusion surface and the surface is sealed. The second end cover plate is integrated with a liquid cooling pipeline, which can timely cool the high temperature at the tin material chamber in the first end cover plate to ensure that the acoustic generation device is not affected by the high temperature. The liquid used for liquid cooling can be water, alcohol or oil. Six or more conductive terminals are integrated on the second end cover plate for connecting the internal temperature probe of the tin target generation device and the acoustic generation device. Specifically, the conductive terminal 14 is used to connect the temperature probe inside the device and the piezoelectric ceramic 16 for electrical connection. Sealing can be achieved by bonding or welding.

[0037] In this embodiment, the acoustic generating device and transmitting device 4 and the active cooling device 5 are fixed by the piezoelectric ceramic base 17 and the cooling second end cover plate 19, which is considered as follows: first, the piezoelectric ceramic 16 can be cooled well, and second, the good sealing between the liquid cooling pipeline 13 and the active cooling device 5 can be ensured. In addition, the vibration transmission rod 18 is surrounded by the active cooling device 5, and thermal conductive silicone grease can be applied between the two to achieve better contact, so that the heat transmitted to the acoustic transmission rod 18 through the tail rod end of the special part 9 can be quickly taken away by the active cooling device 5 in time.

[0038] In some embodiments, the liquid cooling pipe 13 on the second end cover plate is connected to the active cooling device through the acoustic generating device. The connection method is bonding or welding to maintain the seal between the active cooling device 5 and the internal space of the overall device. In some embodiments, the liquid cooling pipe on the second end cover plate can be made into an integral part with the acoustic generating device and then connected to the active cooling device. The connection method is bonding or welding. In some embodiments, the liquid cooling pipe on the second end cover plate is connected to the active cooling device through the acoustic generating device. When connecting, the end of the liquid cooling pipe is expanded and can be stuck on the reserved hole of the active cooling.

[0039] The acoustic generating device and the propagating device 4 are fixed on the active cooling device 5, located inside the main shell, and fixed to the first end cover plate 1 through the support member 22. Therefore, compared with the conventional design in which the acoustic generating device and the propagating device 4 are located outside the overall device, the acoustic signal propagation is more stable, which is more conducive to the coupling of the acoustic signal at the small hole 7, thereby forming a more stable tin droplet target.

[0040] The active refrigeration device 5 allows cooling liquid to flow into one end of the liquid cooling pipe 13 and discharge it at the other end to take away the heat. The refrigeration power can be adjusted by the flow rate of the liquid. The adjustment principle is that the temperature at the piezoelectric ceramic 16 is at the working temperature of the piezoelectric ceramic. The refrigeration liquid storage chamber 20 is a partition design, so the sixth gasket required for sealing between the refrigeration liquid storage chamber 20 and the refrigeration second end cover plate 19 is a semicircular design. The seventh gasket required for sealing between the refrigeration liquid storage chamber 20 and the refrigeration first end cover plate 21 is a conventional round gasket.

[0041] In some embodiments, considering that tin can react with oxygen in the air when it is melted, the tiny particles of tin oxide formed by the reaction will adhere to the vicinity of the small hole 7 and interfere with the formation of a stable tin droplet target, so the main body of the device is in a vacuum environment when it is working. The tin liquid chamber 8 on the inner side of the small hole 7 and the space in the main shell are both in a positive pressure state. The other side of the small hole 7 is a vacuum working environment, so the first end cover plate, the second end cover plate and the main shell all have a preset thickness, which can at least withstand the working pressure under the small hole tin liquid spraying state. The seal between the first end cover plate 1 and the main shell and between the second end cover plate and the main shell can be sealed by pressing the second gasket and the third gasket.

[0042] The active cooling device 5 needs to be fixed on the first end cover plate 1. In the working state, the first end cover plate 1 is at a high temperature. In order to prevent the active cooling device 5 from directly contacting the first end cover plate 1, a support member 22 for heat insulation is provided between the active cooling device and the first end cover plate. The support member 22 should have the properties of poor thermal conductivity and high strength, and the material can be ceramic. During assembly, it can be fixed by bonding or welding.

[0043] The small hole 7 on the first end cover plate is fixed and pressed by the small hole cover plate, and the first gasket between the first end cover plate and the small hole cover plate is squeezed to seal. In this embodiment, the small hole material can be ceramic, diamond, stainless steel, chromium-nickel alloy or other material alloys. The material of the first gasket here can be a soft metal or alloy such as oxygen-free copper or silver. When installing the small hole 7 on the first end cover plate 1, the center hole of the small hole cover plate 6 must coincide with the center of the small hole 7. In addition, when sealing between the small hole cover plate 6 and the first end cover plate 1, the fixing force of each screw must be kept equal. In some embodiments, there is a positioning notch on the first end cover plate that can be matched with the small hole cover plate, so that the center hole of the small hole cover plate and the small hole can coincide with the center of the circle. In some embodiments, for the convenience of assembly, the small hole cover plate 6, the small hole 7 and the eighth gasket between the two can be designed as a nut design as a whole, and matched with the corresponding threaded joint of the first end cover plate 1 for installation. In this embodiment, the tin liquid chamber 8 is designed to be conical near the small hole 7, so that the acoustic vibration excitation signal can be better coupled to the small hole 7. The working pressure applied by the pressurized pipeline 23 mainly drops at the small hole 7, so the small hole cover plate 6 is gradually opened in the direction away from the small hole 7, which is conducive to bearing pressure and avoiding deformation of the small hole 7 when the working pressure is too high.

[0044] Since the first end cover plate 1 is at high temperature in the working state, it is necessary to consider the assembly error caused by the thermal expansion and contraction effect of its assembly parts. Therefore, for the eighth gasket at the small hole 7, an interference fit is selected, and a material with a greater expansion rate than stainless steel is selected, such as silver. The material of the small hole 7 can be ceramic, diamond, stainless steel, chromium-nickel alloy or other material alloys. Generally, ultrafast laser drilling or plasma drilling technology is used for processing. The small hole can be a straight hole or a tapered hole.

[0045] In particular, when installing the special part 9 on the first end cover plate 1, it is necessary to ensure that the vibration center of the special part 9 is located at the center of the opening circle of the tin liquid chamber 8 as much as possible. Considering that the acoustic vibration can be effectively coupled with the tin liquid in the chamber, it is better transmitted to the small hole 7. It is more conducive to forming a stable tin droplet target. In addition, when sealing between the special part cover plate 10 and the first end cover plate 1, the fixing force of each screw should be kept equal.

[0046] Particularly, the materials of the first to eighth gasket washers can be metal, perfluororubber, polyimide, etc.

[0047] In the working state of the present invention, the tin liquid chamber 8 is under positive pressure, and the positive pressure is maintained by the pressurized pipeline 23. When maintaining the pressure, one of the pipelines can be kept pressurized, or the two pipelines can be connected to the same pressure source for pressurization. The heating rods 11 are opened at the same time or partially opened for heating. The heating distribution can be judged by the temperature feedback collected by the temperature sensors distributed on the special-made pressure plate 10. The heating principle is to ensure that the tin liquid in the tin liquid chamber 8 and the pressurized pipeline 23 is always in a molten state. At this time, the tin liquid is sprayed from the small hole 7 into the working environment.

[0048] The special part 9 couples the acoustic excitation signal transmitted from the acoustic transmission rod 18 to the small hole 7, thereby causing the jet flow at the small hole 7 to undergo Rayleigh rupture, forming a stable tin droplet target. The size, spacing, and frequency of the tin droplet target can be adjusted by adjusting the excitation signal of the piezoelectric ceramic 16. When the pressure applied by the pressurized pipeline 23 is constant, the higher the frequency of the excitation signal applied to the piezoelectric ceramic 16, the smaller the diameter of the tin droplet target and the smaller the spacing. When the frequency of the excitation signal applied to the piezoelectric ceramic 16 is constant, the greater the pressure of the pressurized pipeline 23, the smaller the diameter of the tin droplet target and the larger the spacing.

[0049] In this embodiment, the pressure applied to the pressurized pipeline 23 is 80 psi, a 100 KHz sinusoidal signal is applied to the piezoelectric ceramic 16, the aperture 7 is 25 μm, the tin droplet size is about 30 microns at 30 mm from the outlet, the spacing is about 100 μm, and the frequency is 100 KHz.

[0050] The present invention provides a liquid drop tin target supply device required for an extreme ultraviolet light source, which can provide a tin liquid target with extremely high spatial stability and good high-frequency repeatability, and has simple operation and reliable method.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A droplet tin target supply device for an extreme ultraviolet light source, characterized in that: The device comprises a device shell and an acoustic generation and propagation device arranged in the device shell, wherein the device shell comprises a main shell and a first end cover plate and a second end cover plate arranged thereon, wherein the first end cover plate is integrated with a chamber for storing liquid tin and a small hole cover plate connected to the chamber, wherein the chamber for storing liquid tin is connected with a feed pipe, and the small hole cover plate is provided with small holes for tin droplets to flow, and the first end cover plate is also connected with an integrated pressurizing device and a temperature regulating device, wherein the integrated pressurizing device is used to pressurize the chamber for storing liquid tin to obtain a continuous tin jet flow, and the temperature regulating device is used to regulate the temperature of the first end cover plate, and the output end of the acoustic generation and propagation device is connected with the chamber for storing liquid tin, and is used to convert the continuous tin jet flow into a stable tin drop flow, and the acoustic generation and propagation device is equipped with an active refrigeration device, and the second end cover plate is provided with a channel for connecting the active refrigeration device; The output end of the acoustic generation and propagation device is connected to the chamber storing liquid tin on the first end cover plate through a special part, the special part includes a film and a tail rod, one side of the special part is the first end cover plate, and the other side is the special part cover plate, the output end of the acoustic generation and propagation device is connected to the tail rod of the special part, and the generated acoustic vibration is transmitted to the film of the special part, thereby driving the tin droplet generating device to generate stable tin droplets; The acoustic generation and propagation device includes a piezoelectric ceramic cap, a piezoelectric ceramic, a piezoelectric ceramic base and an acoustic transmission rod, the output end of the piezoelectric ceramic is connected to the acoustic transmission rod, the piezoelectric ceramic is mounted on the piezoelectric ceramic base, and the piezoelectric ceramic cap is pressed tightly on the piezoelectric ceramic.

2. The droplet tin target supply device of the extreme ultraviolet light source according to claim 1, characterized in that: The temperature regulating device comprises a heating rod and a temperature probe, and the voltage at both ends of each heating rod is feedback-regulated by reading the temperature at the temperature probe.

3. The droplet tin target supply device of the extreme ultraviolet light source according to claim 1, characterized in that: The second end cover plate is integrated with an air pressure balancing pipeline, and the air pressure balancing pipeline is used to balance the pressure on both sides of the film.

4. The droplet tin target supply device of the extreme ultraviolet light source according to claim 1, characterized in that: The size, spacing and frequency of the formed tin droplet targets are adjusted based on the excitation signal of the piezoelectric ceramic.

5. The droplet tin target supply device of the extreme ultraviolet light source according to claim 1, characterized in that: The active cooling device includes a cooling first end cover plate, a cooling second end cover plate and a cooling liquid storage chamber. The liquid cooling pipeline is installed on the second end cover plate through a liquid cooling pipeline pressing plate. The output end of the liquid cooling pipeline passes through the piezoelectric ceramic base of the acoustic generation and transmission device, and extends into the cooling liquid storage chamber between the cooling first end cover plate and the cooling second end cover plate. The cooling liquid storage chamber is wrapped around the outside of the acoustic transmission rod of the acoustic generation and transmission device.

6. The droplet tin target supply device of the extreme ultraviolet light source according to claim 1, characterized in that: The main body of the droplet tin target supply device of the extreme ultraviolet light source is in a vacuum environment when in working state, and the first end cover plate, the second end cover plate and the main shell all have a preset thickness, which can at least withstand the working pressure in the small hole tin liquid spraying state.

7. The droplet tin target supply device of the extreme ultraviolet light source according to claim 1, characterized in that: A support member for heat insulation is provided between the active refrigeration device and the first end cover plate.

8. The droplet tin target supply device of the extreme ultraviolet light source according to claim 1, characterized in that: The small hole on the first end cover plate is fixed and pressed by the small hole cover plate, and sealed by squeezing the first gasket between the first end cover plate and the small hole cover plate. The first end cover plate has a positioning groove that can cooperate with the small hole cover plate to facilitate the center hole of the small hole cover plate and the small hole to coincide with each other.

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