JP2022515973A - A device for controlling the introduction of EUV target material into the EUV chamber. - Google Patents

Abstract

A device for controlling the guidance of the EUV target material into the EUV chamber, where the flow limiter orifice is in the flow path of the target material through the droplet generator, for example at the upstream position of the filter in the droplet generator. Be placed. Also, a liquid tin sensor, such as a conduction probe or an electrical load detector, may be located within the volume of the heater block of the droplet generator. The flow limiter can be additionally configured to act as a seal, eg, for a filter. Therefore, the flow limiter can be configured as a metal disc that can also serve as a sealing gasket. For example, the metal may be unannealed tantalum, tantalum tungsten alloy, annealed molybdenum, molybdenum rhenium alloy, or annealed rhenium. [Selection diagram] Fig. 4

Description

Cross-reference of related applications
[0001] The present application claims the priority of US Application No. 62 / 786,622 filed December 31, 2018, which is incorporated herein by reference in its entirety.

[0002] The present application relates to extreme ultraviolet ("EUV") light sources and how they operate. These light sources provide EUV light by producing plasma from the target material. In one application, EUV light can be collected and used in a photolithography process to generate a semiconductor integrated circuit.

[0003] A patterned beam of EUV light can be used to expose a resist coated substrate, such as a silicon wafer, to generate extremely small features within the substrate. EUV light (sometimes referred to as soft X-rays) is usually defined as electromagnetic radiation with wavelengths in the range of about 5 nm to about 100 nm. In the case of photolithography, one particular wavelength of interest occurs at 13.5 nm.

[0004] Methods for producing EUV light include, but are not limited to, converting a target material (also referred to as a source material) having chemical elements with emission lines within the EUV range into a plasma state. These elements can include, but are not limited to, xenon, lithium, and tin.

[0005] In one such method, a laser beam is used to irradiate a target material, for example in the form of droplets, streams, or wires, to produce the desired plasma, often referred to as a laser-generated plasma (“LPP”). be able to. Alternatively, the required plasma, often referred to as a discharge-generating plasma (“DPP”), is by positioning a source material with a suitable emission line between a pair of electrodes and causing a discharge between the electrodes. , Can be generated.

[0006] One technique for producing droplets is to melt a target material such as tin and then generate a laminar fluid jet with velocities in the range of about 30 m / s to about 200 m / s. This involves applying high pressure in the droplet generator through a relatively small diameter orifice, such as an orifice having a diameter of about 0.1 μm to about 30 μm. Under most conditions, the jet splits into droplets due to hydrodynamic instability called Rayleigh plateau instability. These droplets can have variable velocities and can combine with each other to coalesce into larger droplets.

[0007] The molten target material is maintained under high pressure by connecting the container holding the target material to a high pressure gas source such as an inert gas, such as argon. In such an arrangement, the droplet generator impedes the leakage and tolerance of uncontrolled flow of the target material under pressure into the chamber containing the system optics such as collector mirrors, thus targeting the optics. There is a risk of contamination with.

[0008] For droplet generators operating at 3,000-4,000 PSI pressures within EUV sources, a fail-safe system using a device called a fast vent system (RVS) is used. To prevent widespread contamination of the source vacuum chamber by shutting off the supply of high pressure gas to the vessel and by rapidly venting the droplet generator into a large gas tank called a high speed vent tank (RVT), the RVS The signal from the gas flow switch is used to detect significant tin leaks caused by the failure of one of the droplet generator components. In the absence of RVS, nozzle failure can instantly introduce large amounts of tin contamination into the chamber.

[0009] There are some possible drawbacks and limitations of the RVS system as described. For example, during pressurization of the droplet generator, the gas volume flow rate changes (mass flow rate is constant). Before the gas pressure reaches ~ 400 PSI, the gas flow rate exceeds the threshold of the RVS flow switch, resulting in activation of the RVS. Therefore, as a practical matter, the RVS system typically cannot initiate pressurization of the droplet generator and allows accelerated pressurization, but the EUV source remains unprotected from conditions such as nozzle breakage. Become.

[0010] Also, the activation threshold of the RVS flow switch must be selected to respond to the conditions encountered during normal operation, but to the expected failure. Attempting to meet these criteria also sometimes works, for example, during the initial pressurization as described above, when the switch does not always work when it should work, or when it should not. Force a compromise to do. For flow switches to detect tin leaks, the tin flow must exceed the minimum value. Detection may fail if the capillaries are too small in diameter, if the orifice is chipped, or if only a small portion of the capillaries is broken.

[0011] An example of the limitation is to effectively limit the pressure rating of the current RVS component to a pressure of about 4,000 PSI for the droplet generator operation. Higher pressure systems can be developed, but as the pressure rating increases, the conductance of the components decreases, and thus the decompression rate also decreases, eliminating the effect of the fast decompression scheme on source protection described above.

[0012] One example of the drawback is that the RVS is large, heavy and requires a connection with a stiff hose. This puts an extra load on the droplet generator steering system and reduces control performance. Also, the size of the RVT is very large (about 300L) and occupies a considerable space in the manufacturing facility. When operating at higher droplet generator pressures, the hose needs to be stiffer and the RVT needs to be larger. In addition, depressurizing the operable droplet generator at high speed may give an adverse impact to the droplet generator, and the next start may not be successful.

[0013] Therefore, it is still necessary to address target material leakage from the droplet generator to avoid these limitations and shortcomings.

[0014] The following is a brief overview of one or more embodiments to give a basic understanding of this embodiment. This overview is not intended to be an broad overview of all intended embodiments, but to identify key or essential elements of all embodiments, or to elaborate on the scope of any or all embodiments. Not. It is intended only to present some concepts of one or more embodiments in a simple form as a prelude to a more detailed description presented later.

[0015] According to one embodiment of the embodiment, the flow limiter orifice is placed in the flow path of the target material through the droplet generator, eg, at an upstream position of the filter in the droplet generator. Also, a liquid target material level sensor, such as a conduction probe or electrical load detector (ELD), can be used and may be located within the volume of the droplet generator heater block. The flow limiter can be configured to act additionally, for example, as a seal for a filter. Therefore, the flow limiter can be configured as a disc that can also act as a sealing gasket. For example, the disc can be made of a metal such as unannealed tantalum, tantalum tungsten alloy, annealed molybdenum, molybdenum rhenium alloy, and annealed rhenium, or a fire resistant material.

[0016] Other embodiments, features, and advantages of the present invention, as well as the structures and operations of the various embodiments, are described in detail below with reference to the accompanying drawings.

[0017] The accompanying drawings incorporated herein and forming part of the present specification illustrate the methods and systems of embodiments of the invention by way of example, but not by limitation. The drawings, along with a detailed description, serve to illustrate the principles of the methods and systems presented herein and to allow one of ordinary skill in the art to create and use the methods and systems. In the drawings, the same reference numbers represent the same or functionally similar elements.

[0018] A simplified schematic of an EUV light source coupled with an exposure device. [0019] FIG. 3 is a simplified schematic representation of a device comprising an EUV light source with an LPP EUV light emitter. [0020] It is a schematic diagram showing a droplet generation subsystem for an EUV light source. [0021] FIG. 6 is a schematic diagram illustrating a conventional system for limiting leakage of target material in an EUV generation system. [0022] FIG. 6 is a non-constant scale diagram showing an arrangement for limiting leakage of EUV target material into an EUV chamber, according to one embodiment of the embodiment. [0023] FIG. 3 is a plan view showing various exemplary embodiments of a flow limiter according to an embodiment. [0023] FIG. 3 is a plan view showing various exemplary embodiments of a flow limiter according to an embodiment. [0023] FIG. 3 is a plan view showing various exemplary embodiments of a flow limiter according to an embodiment. [0023] FIG. 3 is a plan view showing various exemplary embodiments of a flow limiter according to an embodiment. [0024] FIG. 6 is a partial cut-out view showing a portion of the system for limiting leakage of target material in an EUV generation system, according to one embodiment of the embodiment.

[0025] Another feature and advantage of the invention and the structure and operation of various embodiments of the invention will be described in detail below with reference to the accompanying drawings. It should be noted that the invention is not limited to the particular embodiments described herein. Such embodiments are described herein for purposes of illustration only. Those skilled in the art will readily come up with further embodiments based on the teachings contained herein.

[0026] Next, various embodiments will be described with reference to the drawings. Throughout the text, the same reference number is used with reference to the same element. In the following description, for purposes of illustration, many specific details are given to facilitate a complete understanding of one or more embodiments. However, in some or all cases, it will be clear that any of the embodiments described below can be implemented without adopting the specific design details described below. In other cases, well-known structures and devices are shown in the form of block diagrams to facilitate the description of one or more embodiments.

[0027] Reference to FIG. 1 at the beginning shows a simplified schematic cross-sectional view of a selected portion of an example of an EUV photolithography appliance, generally designated as 10 ″. The device 10 ″ can be used, for example, to expose a substrate 11 such as a resist coated wafer using a beam patterned with EUV light. In the case of apparatus 10'', for example, one or more optical systems 13a, 13b, and one or more optical systems 13a, 13b, for illuminating the patterning optical system 13c, such as a reticle, using a beam of EUV light to generate a patterned beam. An exposure device using EUV light 12'' (eg, a stepper, a scanner, a step and a scanning system) having one or more reduced projection optical systems 13d, 13e for projecting a patterned beam onto the substrate 11. Integrated circuit lithography tools such as direct write systems, devices that use contact and / or proximity masks) can be provided. Mechanical assembly (not shown) can be provided to generate controlled relative motion between the substrate 11 and the patterning means 13c. As further shown in FIG. 1, the apparatus 10 ″ is an EUV light into the chamber 26 ″ that is reflected by the optical system 24 along the path into the exposure device 12 ″ to illuminate the substrate 11. Can include an EUV light source 20'', including an EUV light emitter 22 that radiates light. Lighting systems include various types of optical components for inducing, shaping, or controlling radiation, such as refraction, reflection, electromagnetic, electrostatic, or any other type of optical component, or any combination thereof. be able to.

[0028] As used herein, the term "optical system" and its derivatives include, but are not limited to, one or more components that reflect and / or transmit incident light and / or operate. One or more lenses, windows, filters, prisms, grisms, grids, transmission fibers, etalons, diffusers, homogenizers, detectors, and other instrument components, apertures, axicons, multi-layer mirrors, near-field incident mirrors, hazy incident mirrors. , A mirror, including, but not limited to, a mirror surface reflector, a diffuse reflector, and a combination thereof. Further, unless otherwise specified, the term "optics" or its derivatives, as used herein, are also suitable for components operating independently, or for EUV output light wavelengths, irradiation laser wavelengths, metrology. It does not mean that it should be limited to advantages within one or more specific wavelength ranges, such as wavelength, or any other specific wavelength.

[0029] FIG. 1A shows a particular example of a device 10 comprising an EUV light source 20 with an LPP EUV light emitter. As shown in the figure, the device 10 can include a system 21 for generating a sequence of light pulses and for transporting the light pulses into the light source chamber 26. In the case of the apparatus 10, the light pulse is one from the system 21 into the chamber 26 to illuminate the source material in the irradiation region 48 and generate EUV light output for substrate exposure in the exposure device 12. It can travel along the above beam path.

Suitable lasers for use within the system 21 shown in FIG. 1A are pulsed laser devices, such as relatively high power, such as 10 kW or higher, and high pulse repetition rates, such as 50 kHz or higher. A 9.3 μm or 10.6 μm pulsed gas discharge CO ₂ laser device that operates above and produces radiation, eg, DC or RF excitation, can be included. In one particular embodiment, the laser has an oscillator amplifier configuration with multiple stages of amplification (eg, main oscillator power amplifier (MOPA) or power oscillator / power amplifier (POPA)) and has relatively low energy. And with a high repeat rate, eg, an axial flow RF pump CO ₂ laser with a seed pulse initiated by a Q-switched oscillator capable of 100 kHz operation. The laser pulse from the oscillator can then be amplified, shaped and / or focused before reaching the irradiation area 48. A continuous pump CO ₂ amplifier can be used in the laser system 21. Alternatively, the laser can be configured as a so-called "self-targeting" laser system in which the droplet acts as a mirror of the optical cavity.

Other types of lasers may also be suitable, for example, excimers or molecular fluorine lasers operating at high power and high pulse repetition rates, depending on the application. Other examples include, for example, solid-state lasers with fibers, rods, slabs, or disk-type active media, and one or more chambers, such as oscillator chambers (with parallel or series amplification chambers) and one or more. Seed other laser architectures with amplification chambers, main oscillator / power oscillator (MOPO) arrangements, main oscillator / power ring amplifier (MOPRA) arrangements, or one or more excima, molecular fluorine or CO ₂ amplifiers or oscillator chambers. Solid-state lasers may be suitable. Other designs may also be suitable.

[0032] In some instances, the source material can be first irradiated with a prepulse and then with a main pulse. The pre-pulse seed and main pulse seed can be generated by a single oscillator or two separate oscillators. In some setups, one or more common amplifiers can be used to amplify both the pre-pulse seed and the main pulse seed. For other configurations, separate amplifiers can be used to amplify the pre-pulse seed and main pulse seed.

[0033] FIG. 1A is a beam conditioning unit having one or more optical systems for beam conditioning such as dilating, steering, and / or focusing the beam between the laser source system 21 and the irradiation site 48. Also shown is device 10, which may include 50. For example, a steering system may be provided that may include one or more mirrors, prisms, lenses, etc., and the focal point of the laser can be arranged to steer to various locations within the chamber 26. For example, the steering system can move the first flat mirror mounted on a movable actuator that can move the first mirror independently in two directions and the second mirror independently in two directions. A second flat mirror mounted on the movable actuator can be included. With this arrangement, the steering system can controlly move the focal point in a direction substantially perpendicular to the beam propagation direction (beam axis).

[0034] The beam adjusting unit 50 can include a focus assembly for focusing the beam on the irradiation site 48 and adjusting the position of the focal point along the beam axis. For focus assemblies, optical systems such as focus lenses or mirrors coupled to actuators can be used for movement along the beam axis to move the focus along the beam axis.

[0035] Further, as shown in FIG. 1A, the EUV light source 20 also includes a source material delivery system 90 that transports a target or source, such as tin droplets, to the irradiation area or primary focus 48 inside the chamber 26. The droplets can interact with the light pulse from the system 21 to eventually generate plasma and create EUV emissions for exposing a substrate such as a resist coated wafer in the exposure device 12. Become. Further details on the various droplet dispenser configurations and their relative advantages can be found in US Patent No. 7 entitled "Systems and Methods for Target Material Delivery in a Laser Produced Plasma EUV Light Source" issued January 18, 2011. , 872,245, US Pat. No. 7,405,416 entitled "Method and MFP For EUV Plasma Source Target Delivery" issued July 29, 2008, and "LPP" issued May 13, 2008. It is described in US Pat. No. 7,372,056 entitled "EUV Plasma Source Material Target Delivery System", the contents of each of which are incorporated herein by reference in their entirety.

[0036] Source materials for producing EUV light output for substrate exposure can include, but are not limited to, materials containing tin, lithium, xenon, or combinations thereof. EUV emitting elements such as tin, lithium, xenone and the like can be in the form of droplets and / or solid particles contained within the droplets. For example, elemental tin can be used as pure tin as tin compounds, such as SnBr ₄ , SnBr ₂ , SnH ₄ , as tin alloys such as tin gallium alloys, tin indium alloys, tin indium gallium alloys, or combinations thereof. can. Depending on the material used, the source material can be at various temperatures, including room temperature or near room temperature (eg, tin alloy, SnBr ₄ ), at high temperatures (eg, pure tin), or at temperatures below room temperature (eg, eg, pure tin). SnH ₄ ), can be presented in the irradiated area, and in some cases can be relatively volatile, such as SnBr ₄ .

[0037] Continuing with reference to FIG. 1A, apparatus 10 controls the device in system 21 to generate an optical pulse for carrying it into chamber 26 and / or in beam conditioning unit 50. An EUV controller 60, which may also include a drive laser control system 65 for controlling the movement of the optical system of the above, can also be included. The device 10 may also include, for example, a droplet position detection system that may include one or more droplet imagers 70 that provide an output indicating the location of one or more droplets relative to the irradiation area 48. The imager 70 can provide this output to the droplet position detection feedback system 62, which calculates, for example, the position and orbit of the droplet, from which, for example, droplet by droplet or averaging. It is possible to calculate the droplet error. A droplet error can then be provided to the controller 60 as an input, the controller 60 providing, for example, a position, direction, and / or timing correction signal to the system 21 to control the laser trigger timing and / or, for example. It is possible to control the movement of the optical system in the beam conditioning unit 50 in order to change the location and / or focal power of the optical pulse delivered to the irradiation area 48 in the chamber 26. For the EUV light source 20, the source material delivery system 90 also responds to a signal from the controller 60 (which, in some embodiments, may include the aforementioned droplet error, or any amount derived). A control system that can be operated to correct, for example, the release point, the initial droplet stream direction, the droplet release timing, and / or the droplet adjustment to correct for errors within the droplet that reach the desired irradiation area 48. Can have.

[0038] Continuing with FIG. 1A, the apparatus 10 comprises, for example, an alternating layer of molybdenum and silicon and, in some cases, one or more high temperature diffusion barrier layers, a smoothing layer, a capping layer, and / or an etching stop layer. It can also include an optical system 24'', such as a near-normal incident collector mirror, with a reflective surface in the form of a prolate spheroid (ie, an ellipse that rotates around its major axis), with a slanted multilayer coating. .. FIG. 1A shows that the optical system 24 ″ can be formed with an aperture to allow the optical pulse generated by the system 21 to pass through and reach the irradiation region 48. As shown in the figure, the optical system 24'' includes, for example, a long sphere mirror having a primary or primary focus in or near the irradiation region 48 and a second focus in the so-called intermediate region 40. The EUV light can be output from the EUV light source 20 and input to an exposure device 12 utilizing the EUV light, for example, an integrated circuit lithography tool. It will be appreciated that other optical systems can be used in place of the prolate spheroid mirror to collect light and direct it to an intermediate location and then deliver it to devices that utilize EUV light.

[0039] Buffer gas, such as hydrogen, helium, argon, or a combination thereof, can be introduced into, replenished, and / or removed from chamber 26. The buffer gas can be present in the chamber 26 during the plasma discharge and can act to slow down the plasma generated ions in order to reduce optical degradation and increase plasma efficiency. Alternatively, a magnetic field and / or an electric field (not shown) can be used alone or in combination with a buffer gas to reduce fast ion damage.

[0040] FIG. 2 shows the droplet generation system in more detail. The source material delivery system 90 transports the droplets to the irradiation site / primary focus 48 in chamber 26. The waveform generator 230 provides a drive waveform to the electrically operable element within the droplet generator 90 and induces velocity perturbations within the droplet stream. The waveform generator operates under the control of the controller 250, at least partially based on the data from the data processing module 252. The data processing module receives data from one or more detectors. In the illustrated example, the detector includes a camera 254 and a photodiode 256. The droplet is illuminated by one or more lasers 258. In this typical arrangement, the detector detects / images the droplet at a point in the stream where coalescence is expected to occur. Also, the detector and laser are located outside the vacuum chamber 26 and view the stream through the window on the wall of the vacuum chamber 26.

[0041] FIG. 3 illustrates the components of the simplified droplet source 92 in schematic form. As shown in the figure, the droplet source can include a reservoir 94 that holds the fluid 96, eg, molten tin, under pressure. Also, as shown in the figure, the reservoir 94 can be formed with an orifice that allows the pressurized fluid 96 to flow through the nozzle 95, after which it establishes a stream that splits into a plurality of droplets. .. The droplet source 92 further comprises a subsystem 98 that creates a disturbance in the fluid, having an electrically operable element operably coupled to the fluid 96. The droplet source 92 also includes a filter 100 to prevent contaminants in the fluid 96 from reaching and contaminating components downstream of the droplet source 92. The droplet source 92 also includes a heater block 104 to keep the components of the droplet generator positioned within the cavity defined by the heater block 104 at a temperature high enough to keep the fluid 96 in a molten state. ..

[0042] As described above, the fluid 96 in the reservoir 94 is pressurized by the connection with the gas source 106. The gas is supplied to the reservoir 94 via the valve 108. As described above, the valve 108 is a three-part valve capable of venting the reservoir 94 to the storage tank 110 if the fluid 96 is identified as leaking. Various shortcomings and limitations of the leak control system as described are described above.

[0043] FIG. 4 shows an improved system to prevent leakage of the droplet source 92 from overly contaminating the EUV chamber. As can be seen in the figure, the arrangement of FIG. 4 includes a flow limiter 200 positioned within a conduit that carries the fluid 96 from the reservoir 94 via the droplet source 92. In the illustrated arrangement, the flow limiter 200 is positioned upstream of the filter 100. The function of the flow limiter 200 can be combined with the function of the seal of the filter 100. In other words, the flow limiter 200 can be in the form of a metal disc that can also serve as a sealing gasket.

[0044] FIGS. 5A-5D are plan views of various exemplary embodiments of the flow limiter 200 according to embodiments of the embodiment. FIG. 5A shows a flow limiter 200 configured as a disk 210 with a single orifice 220. FIG. 5B shows a flow limiter 200 configured as a disk 210 with a group 230 of orifices. FIG. 5C shows a flow limiter 200 configured as an annular disk 240 holding a porous membrane 250. FIG. 5D shows a flow limiter 200 configured as a disk 210 with an orifice 220 partially blocked by a pin 260. Both the tapered pin and the conical tube define the throttle because the pin 260 can be a tapered pin and the orifice 220 can be surrounded by a cylindrical element such as a short tube that can be tapered to be conical. Become. Those skilled in the art will find that other configurations are capable of similar work.

[0045] The flow limiter 200 is designed to allow a suitable tin flow to fill the droplet generator nozzle volume without affecting jet performance, but among the elements of the downstream droplet generator. When one fails, it must be sufficiently constrained to limit the flow of fluid. In addition, the flow limiter 200 is configured so that when the droplet generator is first heated, sufficient gas flow can empty the volume of the new droplet generator nozzle and filter. If the conductance is too small, contaminants such as water vapor cannot be removed and can react with tin to form particles that can clog the nozzle. For example, if the flow limiter is configured as shown in FIG. 5A and the droplet generator operates at 8,000 PSI, the diameter of the orifice can be in the range of about 65 μm to about 75 μm. When the fluid 26 is molten tin, its flow through the broken capillaries (having an inner diameter of 500 μm) is slow enough to diminish without leaking out of the heater block cavity of the droplet generator. This flow rate also provides a relatively long time of approximately 100-180 seconds to depressurize the tin levels in the cavity without reaching the holes where they may flow out.

[0046] In various embodiments, the flow limiter 200 is capable of surviving a high differential pressure applied across the flow limiter 200 when one of the elements of the downstream droplet generator fails. This can be achieved by proper design of the flow limiter 200 and selection of materials. The material must be flexible enough to be deformed by the fitting to form the seal, and also have sufficient strength to cope with the maximum pressure applied. The material can be a metal such as unannealed tantalum, tantalum tungsten alloy, annealed molybdenum, molybdenum rhenium alloy, and annealed rhenium, or a fire resistant material.

FIG. 6 also serves as a seal between a portion of the conduit portion 600 connected to the reservoir 94 (not shown) and the conduit portion 610 connected to the filter 100 (not shown). It is a partial cut-out view which shows the detail of the positioning of the limiter 200. As can be seen in the figure, the flow limiter 200 limits the conduit at the interface and also acts as a sealing member between the two conduit portions.

[0048] With reference to FIG. 4 again, a fluid level sensor 300 designed to detect whether a fluid is leaking in the droplet source 92 is also shown. The fluid level sensor 300 can be any suitable sensor for detecting the fluid level at the base of the droplet generator. When the fluid 96 is conductive, as in the case of molten tin, the fluid level sensor 300 can be, for example, a conductive type sensor or an electrical load detector. When the fluid level sensor 300 determines that the fluid has accumulated in the droplet generator, the fluid level sensor 300 decompresses the droplet generator and stops the operation of the source, for example, the data processing module 252. The output signal indicated by the arrow A, which can be supplied in FIG. 2 (FIG. 2), is expanded.

As shown in the figure, the fluid level sensor 300 can be configured as a tin leak sensor in the heater block cavity of the droplet generator. It can be configured as a contact to which a voltage is supplied and supported, for example, by an insulator block 310 at a distance from the conductive metal chassis of the droplet source 92. As the tin level rises, the liquid tin completes the circuit between the contact 300 and the chassis, thus shorting the circuit and showing 0V on the return signal.

[0050] In the above, the present invention has been described with reference to functional components exemplifying embodiments of specific functions and their relationships. The boundaries of these functional components are arbitrarily defined herein for convenience of explanation. Alternative boundaries can be defined as long as a particular function and its relationships are properly performed.

[0051] The aforementioned description of a particular embodiment has fully clarified the overall nature of the invention, and by applying knowledge of the art, the whole of the invention can be done without undue experimentation. Such particular embodiments can be easily modified and / or adapted to a variety of applications without departing from the concept. Accordingly, such indications and modifications shall fall within the meaning and scope of the equivalents of the disclosed embodiments, based on the teachings and guidance presented herein. It is understood that the representations or terms herein are to be interpreted by those skilled in the art in terms of teaching and guidance, as the representations or terms herein are for illustrative purposes only. Let's see. The breadth and scope of the invention are not limited by any of the exemplary embodiments described above and should be defined only in accordance with the following claims and their equivalents. Other aspects of the invention are described in the numbered clauses below.

1. 1. It ’s a device,
With a vacuum chamber,
An optical element positioned in a vacuum chamber, wherein the optical element has a primary focus in the vacuum chamber.
A target material dispenser that is arranged to distribute the target material to the irradiation site at the primary focus in the vacuum chamber, the target material dispenser propagating the target material from the target material reservoir, the nozzle, and the target material reservoir to the nozzle. A target material dispenser and a flow limiter positioned within the conduit to limit the flow of the target material through the conduit.
The device.
2. 2. The device according to clause 1, wherein the flow limiter is configured as a seal.
3. 3. The device according to clause 1, wherein the flow limiter is configured as an optical disc.
4. The device according to clause 3, wherein the disc is configured as a seal.
5. The device according to clause 3 or 4, wherein the disc contains metal.
6. The device according to clause 5, wherein the disc contains tantalum that has not been annealed.
7. The device according to clause 5, wherein the metal disc comprises a tantalum tungsten alloy.
8. The device according to clause 5, wherein the disc contains annealed molybdenum.
9. The device according to clause 5, wherein the disc contains a molybdenum rhenium alloy.
10. The device according to clause 5, wherein the disc contains rhenium annealed.
11. The device of clause 1, wherein the flow limiter is configured as a disk with a single orifice.
12. The device of clause 1, wherein the flow limiter is configured as a disk with multiple orifices.
13. The device according to clause 1, wherein the flow limiter is configured as an annular disk holding a porous membrane.
14. The device of clause 1, wherein the flow limiter is configured as a disk with an orifice that is partially blocked by a pin.
15. The device according to clause 14, wherein the pin is tapered.
16. 25. The device of clause 15, wherein the flow limiter comprises an orifice surrounded by a cylindrical element.
17. 16. The device of clause 16, wherein the cylindrical element comprises a tube.
18. The device according to clause 17, wherein the tube is tapered to form a cone.
19. The device of clause 1, further comprising a liquid level sensor, arranged to detect the accumulation of target material in the target material dispenser.
20. 25. The device of clause 19, wherein the liquid level sensor further comprises a conduction probe.
21. 19. The device of clause 19, wherein the liquid level sensor comprises an electrical load detector.
22. 19. The device of clause 19, wherein the target material dispenser further comprises a heater block and a liquid level sensor is located within the heater block.
23. It ’s a device,
With a vacuum chamber,
An optical element positioned in a vacuum chamber, wherein the optical element has a primary focus in the vacuum chamber.
A target material dispenser arranged to distribute the target material to the irradiation site at the primary focal point in the vacuum chamber, the target material dispenser is located between the target material reservoir, the filter, the target material reservoir and the filter. A target material dispenser, comprising a fluid conduit that establishes a fluid connection between the target material reservoir and the filter, and a flow limiter positioned within the conduit to limit the flow of the target material through the conduit.
The device.
24. The device of clause 23, wherein the flow limiter is configured as a seal.
25. The device according to clause 23, wherein the flow limiter is configured as a disk.
26. 25. The device of clause 25, wherein the disc is configured as a seal.
27. 25. The device according to clause 25 or 26, wherein the disc contains metal.
28. The device according to clause 27, comprising tantalum in which the disc has not been annealed.
29. The device according to clause 27, wherein the metal disc comprises a tantalum tungsten alloy.
30. 28. The device of clause 27, wherein the disc contains molybdenum annealed.
31. The device according to clause 27, wherein the disc contains a molybdenum rhenium alloy.
32. 28. The device of clause 27, wherein the disc contains rhenium annealed.
33. 23. The device of clause 23, wherein the flow limiter is configured as a disk with a single orifice.
34. 23. The device of clause 23, wherein the flow limiter is configured as a disk with multiple orifices.
35. 23. The device of clause 23, wherein the flow limiter is configured as an annular disk holding a porous membrane.
36. 23. The device of clause 23, wherein the flow limiter is configured as a disk with an orifice that is partially blocked by a pin.
37. The device of clause 36, wherein the pin is tapered.
38. 23. The device of clause 23, wherein the flow limiter comprises an orifice surrounded by a cylindrical element.
39. 38. The device of clause 38, wherein the cylindrical element comprises a tube.
40. The device of clause 39, wherein the tube is tapered to form a cone.
41. The device of clause 23, further comprising a liquid level sensor, arranged to sense the level of the target material in the target material reservoir.
42. The device of clause 41, wherein the liquid level sensor further comprises a conduction probe.
43. The device of clause 41, wherein the liquid level sensor comprises an electrical load detector.
44. 42. The device of clause 41, wherein the target material dispenser further comprises a heater block and a liquid level sensor is located within the heater block.
45. A target material dispenser for distributing EUV target materials,
Target material reservoir,
nozzle,
A conduit for propagating the target material from the target material reservoir to the nozzle, and
A flow limiter, positioned within the conduit to limit the flow of target material through the conduit,
Equipped with a target material dispenser.
46. The target material dispenser according to clause 45, wherein the flow limiter is configured as a seal.
47. The target material dispenser according to clause 45, wherein the flow limiter is configured as a metal disc.
48. The device of clause 45, wherein the disc is configured as a seal.
49. The device according to clause 47 or 48, wherein the disc contains metal.
50. The device according to clause 49, comprising tantalum in which the disc has not been annealed.
51. The device according to clause 49, wherein the metal disc comprises a tantalum tungsten alloy.
52. 49. The device of clause 49, wherein the disc contains molybdenum annealed.
53. The device according to clause 49, wherein the disc contains a molybdenum rhenium alloy.
54. The device according to clause 49, wherein the disc contains rhenium annealed.
55. 25. The device of clause 45, wherein the flow limiter is configured as a disk with a single orifice.
56. 25. The device of clause 45, wherein the flow limiter is configured as a disk with multiple orifices.
57. 25. The device of clause 45, wherein the flow limiter is configured as an annular disk holding a porous membrane.
58. 25. The device of clause 45, wherein the flow limiter is configured as a disk with an orifice that is partially blocked by a pin.
59. The device of clause 58, wherein the pin is tapered.
60. 25. The device of clause 45, wherein the flow limiter comprises an orifice surrounded by a cylindrical element.
61. 25. The device of clause 45, wherein the cylindrical element comprises a tube.
62. The device of clause 61, wherein the tube is tapered to form a cone.
63. The device of clause 45, wherein the disc is configured as a seal.
64. The device according to clause 45, wherein the disc contains metal.
65. The device according to clause 64, comprising tantalum whose discs have not been annealed.
66. The device according to clause 64, wherein the metal disc comprises a tantalum tungsten alloy.
67. 60. The device of clause 64, wherein the disc contains molybdenum annealed.
68. The device according to clause 64, wherein the disc contains a molybdenum rhenium alloy.
69. The device according to clause 64, wherein the disc contains rhenium annealed.
70. The target material dispenser according to clause 45, further comprising a liquid level sensor, arranged to sense the level of the target material in the target material reservoir.
71. 20. The target material dispenser according to clause 70, wherein the liquid level sensor comprises a conduction probe.
72. The target material dispenser according to clause 70, wherein the liquid level sensor comprises an electrical load detector.
73. The target material dispenser according to clause 70, wherein the target material dispenser further comprises a heater block and a liquid level sensor is located within the heater block.
74. 25. The target material dispenser according to clause 45, wherein the target material dispenser further comprises a filter between the target material reservoir and the nozzle, and a flow limiter is positioned in the conduit between the target material reservoir and the filter.

Claims (34)

It ’s a device,
With a vacuum chamber,
An optical element positioned in the vacuum chamber, wherein the optical element has a primary focus in the vacuum chamber.
A target material dispenser arranged to distribute the target material to the irradiation site at the primary focal point in the vacuum chamber, wherein the target material dispenser is from the target material reservoir, the dispenser component, the target material reservoir. It comprises a conduit for propagating the target material to the dispenser component and a flow limiter positioned within the conduit to limit the flow of the target material through the conduit, the dispenser component being among nozzles and filters. With at least one of the target material dispensers,
The device. The device according to claim 1, wherein the flow limiter is configured as a seal. The device according to claim 1, wherein the flow limiter is configured as a disk. The device according to claim 3, wherein the disc is configured as a seal. The device according to claim 3, wherein the disc contains metal. The apparatus of claim 5, wherein the disc comprises unannealed tantalum or a tantalum-tungsten alloy. The apparatus of claim 5, wherein the disc comprises annealed molybdenum, annealed rhenium, or a molybdenum rhenium alloy. The device of claim 1, wherein the flow limiter is configured as a disk with a single orifice. The device of claim 1, wherein the flow limiter is configured as a disk with a plurality of orifices. The device according to claim 1, wherein the flow limiter is configured as an annular disk holding a porous membrane. The device of claim 1, wherein the flow limiter is configured as a disk with an orifice partially blocked by a pin. 11. The apparatus of claim 11, wherein the pin is tapered. 11. The device of claim 11, wherein the flow limiter comprises an orifice surrounded by a tube. 13. The device of claim 13, wherein the tube is tapered to form a cone. The device of claim 1, further comprising a liquid level sensor, arranged to detect the accumulation of target material in the target material dispenser. 15. The apparatus of claim 15, wherein the liquid level sensor comprises a conduction probe or an electrical load detector. 15. The apparatus of claim 15, wherein the target material dispenser further comprises a heater block and the liquid level sensor is located within the heater block. The device of claim 1, wherein the dispenser component comprises the filter disposed between the flow limiter and the nozzle. The device of claim 1, wherein the dispenser component comprises the nozzle. A target material dispenser for distributing EUV target materials,
Target material reservoir,
nozzle,
A conduit for propagating the target material from the target material reservoir to the nozzle, and
A flow limiter positioned within the conduit to limit the flow of target material through the conduit,
Equipped with a target material dispenser. The target material dispenser according to claim 20, wherein the flow limiter is configured as a seal. 20. The target material dispenser of claim 20, wherein the flow limiter is configured as a metal disc. 20. The apparatus of claim 20, wherein the disc is configured as a seal. 22. The apparatus of claim 22, wherein the disc comprises metal. 22. The apparatus of claim 22, wherein the disc comprises tantalum or a tantalum tungsten alloy. 22. The apparatus of claim 22, wherein the disc comprises annealed molybdenum, annealed rhenium, or a molybdenum rhenium alloy. 20. The apparatus of claim 20, wherein the flow limiter is configured as a disk with a plurality of orifices. 20. The apparatus of claim 20, wherein the flow limiter is configured as an annular disk holding a porous membrane. 20. The device of claim 20, wherein the flow limiter is configured as a disk with an orifice that is partially blocked by a tapered pin. 20. The device of claim 20, wherein the flow limiter comprises an orifice surrounded by a tapered tube. 20. The target material dispenser according to claim 20, further comprising a liquid level sensor arranged to sense the level of the target material in the target material reservoir. 31. The target material dispenser of claim 31, wherein the liquid level sensor comprises a conduction probe or an electrical load detector. 31. The target material dispenser of claim 31, wherein the target material dispenser further comprises a heater block and the liquid level sensor is located within the heater block. 20. The target material dispenser further comprises a filter between the target material reservoir and the nozzle, and the flow limiter is positioned in the conduit between the target material reservoir and the filter. Target material dispenser.

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