Light source system and extreme ultraviolet light output method

Abstract

The invention relates to the technical field of photoetching, in particular to a light source system and an extreme ultraviolet light output method. The light source system comprises a pinch device, a collecting device and a filtering device; the pinch device comprises a transmitting device and a circuit assembly, the transmitting device is provided with a center hole channel, and the output end of the circuit assembly is close to the center hole channel. The collecting device is arranged between the emitting device and the filtering device, a transition area is arranged on the side, close to the emitting device, of the collecting device, a protection area is arranged on the side, away from the filtering device, of the collecting device, a hollow channel is formed in the collecting device, and first gas and second gas are introduced into the transition area; the first gas is pinched at the central hole channel by plasma generated by ionization to form extreme ultraviolet light; when the extreme ultraviolet light is output, the surface of the emission device is protected through the second gas. The problem that the stability of the extreme ultraviolet light forming process is poor is solved.

Description

Technical field

[0001] The present invention relates to the field of photolithography technology, and in particular to a light source system and an extreme ultraviolet light output method. [Background Technology]

[0002] As a key pillar of the large-scale integrated circuit fabrication process, photolithography machines are a crucial tool for the development of the entire semiconductor industry. With the advancement of photolithography technology, extreme ultraviolet (EUV) lithography has become a consensus within the semiconductor industry. Within the light source system, an electrodeless pinch device can be introduced as a potential EUV generation mechanism. Compared to other EUV generation mechanisms, EUV generated through Z-pinch technology requires less discharge equipment and exhibits higher spatial and temporal stability. The operating process involves the electrodeless pinch device's power system generating high-frequency pulses, which are then fed to xenon (Xe) gas via a coupling unit to generate plasma and form a plasma circuit within the vacuum chamber of the light source system. The magnetic field generated within the plasma circuit causes the plasma to pinch toward the axis, intensifying interparticle collisions and producing high-valence Xe10+ ions. Ultimately, EUV is emitted through the central channel of the emitter within the pinch device.

[0003] However, the primary material of the emitting element in the electrodeless pinch device is copper. When the central channel of the emitting element radiates EUV, the current flowing within the central channel always flows in the direction of minimum impedance. Consequently, this current generates arc discharge, ablating the copper emitting element. This ablation of the emitting element affects the stability of the subsequent UV generation process. In other words, in the prior art, arcing is easily generated between the plasma and the emitting element during the EUV generation process, resulting in poor stability in the EUV generation process. [Summary of the invention]

[0004] In order to solve at least one of the technical problems mentioned in the above background technology, the present invention provides a light source system and an extreme ultraviolet light output method.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] One aspect of the present invention provides a light source system for outputting extreme ultraviolet light, the light source system comprising a pinching device, a collecting device, and a filtering device; the pinching device comprises an emitting device and a circuit assembly, the emitting device having a central hole, and the output end of the circuit assembly being disposed near the central hole;

[0007] The collecting device is disposed between the emitting device and the filtering device. The collecting device defines a transition zone on a side close to the emitting device, and defines a protection zone on a side away from the emitting device. The collecting device defines a hollow channel corresponding to the central channel, and the filtering device defines a filtering channel corresponding to the hollow channel.

[0008] A first gas and a second gas are introduced into the transition zone; the first gas is ionized by the output end of the circuit component to generate plasma that is pinched at the central channel to form extreme ultraviolet light; when the extreme ultraviolet light is output through the central channel, the hollow channel and the filter channel in sequence, the second gas is used to protect the surface of the emitting device.

[0009] Preferably, the transmitting device includes a hollow main body, a first magnetic core and a second magnetic core, the circuit component is at least partially accommodated inside the main body, the main body is provided with a central hole along the axial direction of its central axis, and a plurality of outer holes are provided in the circumferential direction around its central axis, and there is a gap between the outer hole and the central hole, the first magnetic core and the second magnetic core are both arranged inside the main body, the first magnetic core is arranged between the central hole and the outer hole, and the second magnetic core is arranged on the outside of the outer hole away from the central hole.

[0010] Preferably, the circuit assembly includes an energy supply circuit, a first coupling unit, a magnetic pulse compression circuit, and a second coupling unit; the input end of the first coupling unit is connected to the output end of the energy supply circuit, and the output end of the first coupling unit, the magnetic pulse compression circuit, and the input end of the second coupling unit are connected in sequence; the output end of the second coupling unit is the output end of the circuit assembly;

[0011] The energy supply circuit is used to provide current and voltage, which are coupled through a first coupling unit and then transmitted to the magnetic pulse compression circuit to generate a high-current pulse. The first gas is ionized and a high-current pulse is applied to the plasma to form a plasma loop that passes through the central channel and the outer channel in sequence. The plasma loop forms output extreme ultraviolet light under the continuous pinching of the high-current pulse.

[0012] Preferably, the transmitting device further comprises a protective member, and the protective member is arranged on the inner wall surface of the central channel corresponding to the output end of the circuit component.

[0013] Preferably, a filter is provided in the filtering channel corresponding to the extreme ultraviolet light formed by the pinching at the central channel.

[0014] Preferably, the filter comprises a plurality of filter plates, the filter plates are arranged in the filter channel, and the length direction of the filter plates is parallel to the axial direction of the filter channel.

[0015] Preferably, a third gas is introduced into the protection zone, and the third gas is used to protect the filter; a first air inlet pipe for the first gas and / or the second gas is provided in the transition zone, and a second air inlet pipe for the third gas is provided in the protection zone, as well as an air outlet pipe for gas discharge.

[0016] Another aspect of the present invention provides an extreme ultraviolet light output method for protecting an emission device in the above-mentioned light source system, the method comprising:

[0017] providing a first gas, ionizing the first gas to generate plasma, and applying a strong current pulse to the plasma to form a plasma loop;

[0018] continuously applying high current pulses to the plasma loop to generate extreme ultraviolet light and debris at an output of the emission device;

[0019] providing a second gas to protect the surface of the emitting device through the second gas;

[0020] After the extreme ultraviolet light and debris are collected, processed and filtered, the extreme ultraviolet light is output.

[0021] Preferably, after collecting and filtering the extreme ultraviolet light and debris, outputting the extreme ultraviolet light includes:

[0022] Collecting extreme ultraviolet light and debris;

[0023] The extreme ultraviolet light and debris are filtered to filter out the debris;

[0024] A third gas is introduced during filtration, and extreme ultraviolet light is output after filtration.

[0025] Preferably, the second gas is helium, the third gas is nitrogen, and the ratio of the gas flow rate of the helium gas to the gas flow rate of the nitrogen gas is in the range of 1-5.

[0026] In order to solve the above technical problems, the present invention provides another technical solution as follows: a computer device, applied to the above light source system, including a memory, a processor and a computer program stored in the memory, and the processor executes the above computer program to implement the light source system.

[0027] Compared with the prior art, the light source system and extreme ultraviolet light output method provided by the present invention have the following beneficial effects:

[0028] 1. An embodiment of the present invention provides a light source system for outputting extreme ultraviolet light. The light source system includes a pinching device, a collecting device, and a filtering device. The pinching device includes an emitting device and a circuit assembly. The emitting device has a central hole, and the output end of the circuit assembly is located near the central hole.

[0029] The collecting device is arranged between the emitting device and the filtering device. The side of the collecting device close to the emitting device defines a transition zone, and the side of the collecting device away from the emitting device defines a protection zone. The collecting device has a hollow channel corresponding to the central channel, and the filtering device has a filtering channel corresponding to the hollow channel.

[0030] A first gas and a second gas flow into the transition zone. The first gas is ionized by the output of the circuit assembly to generate plasma that is pinched at the central channel to form EUV light. As the EUV light sequentially passes through the central channel, the hollow channel, and the filter channel, the second gas protects the surface of the emission device. In this embodiment, two regions are provided. Helium gas flows into the transition zone, where it forms a non-ionizing insulating layer to protect the emission device, preventing damage from plasma arc discharge and the resulting poor stability of the EUV light generation process.

[0031] 2. The transmitting device of the embodiment of the present invention includes a hollow main body, a first magnetic core and a second magnetic core. The main body is provided with a central hole in the axial direction of its central axis, and a plurality of outer holes in the circumferential direction around its central axis. There is a gap between the outer holes and the central hole. The first magnetic core and the second magnetic core are both arranged inside the main body. The first magnetic core is arranged between the central hole and the outer hole, and the second magnetic core is arranged on the outside of the outer hole away from the central hole. The first magnetic core can generate mutual induction with the plasma circuit. The second magnetic core is soft magnetic and can be used as a switch. After the plasma forms a plasma circuit that passes through the central hole and the outer hole in sequence, it can be pinched at the pinch point and radiate extreme ultraviolet light. The process of radiating extreme ultraviolet light is simple and produces less particle fragments.

[0032] 3. A circuit assembly according to an embodiment of the present invention includes an energy supply circuit, a first coupling unit, a magnetic pulse compression circuit, and a second coupling unit. The input of the first coupling unit is connected to the output of the energy supply circuit, and the output of the first coupling unit, the magnetic pulse compression circuit, and the input of the second coupling unit are sequentially connected. The output of the second coupling unit serves as the output of the circuit assembly.

[0033] The energy supply circuit provides current and voltage, which are coupled through a first coupling unit and then transmitted to the magnetic pulse compression circuit to generate a high-current pulse. The ionized first gas generates a high-current pulse that applies to the plasma, forming a plasma loop that sequentially passes through the central and outer channels. The plasma loop is continuously pinched by the high-current pulse to produce output extreme ultraviolet light. The magnetic pulse compression circuit can perform multi-stage pulse compression on the current and voltage, producing pulses with both high amplitude and wide pulse width, which helps increase the number of plasma pinches and thus obtain higher-power extreme ultraviolet light.

[0034] 4. The transmitter device of this embodiment of the present invention further includes a protective member disposed on the inner wall surface of the central channel, corresponding to the output terminal of the circuit assembly. The protective member provides thermal insulation. Furthermore, the protective member, when attached to the inner wall surface of the central channel, protects the inner wall surface from damage by the high-temperature plasma, thereby improving the durability of the device.

[0035] 5. In the embodiment of the present invention, a filter is provided in the filter channel corresponding to the extreme ultraviolet light formed by the pinch at the central channel. The filter can filter out the influence of debris and impurities, ensuring the output extreme ultraviolet light of good quality.

[0036] 6. The filter of an embodiment of the present invention includes several filter plates, which are arranged in a filter channel, and the length direction of the filter plates is parallel to the axial direction of the filter channel, so that gaps are left between adjacent filter plates in the filter for extreme ultraviolet light to pass through, thereby avoiding the problem of the filter plates blocking the extreme ultraviolet light and causing the extreme ultraviolet light to be unable to be output.

[0037] 7. In the embodiment of the present invention, a third gas is introduced into the protected area to protect the filter. A first inlet conduit for the first and / or second gas is provided within the transition zone, while a second inlet conduit for the third gas is provided within the protected area, along with an outlet conduit for the third gas. The third gas can be bombarded by high-energy particles to form a negatively charged NN structure, which exhibits cationic properties. The NN structure absorbs and consumes electrons, protecting the filter within the filtration device and preventing erosion by high-energy particles in the debris.

[0038] 8. An embodiment of the present invention also provides an extreme ultraviolet light output method, which has the same beneficial effects as the above-mentioned light source system and will not be described in detail here.

Brief Description of the Drawings

[0039] Figure 1 It is a structural diagram of a light source system provided by the first embodiment of the present invention.

[0040] Figure 2a This is a schematic diagram of the process in which arc discharge is generated when plasma radiates into extreme ultraviolet light, thereby ablating the emission device.

[0041] Figure 2b It is a schematic diagram of the process of protecting the launch device with helium provided by the first embodiment of the present invention.

[0042] Figure 3 It is a schematic diagram of the partial structure of the launch device provided in the first embodiment of the present invention.

[0043] Figure 4 It is a schematic diagram of the circuit assembly structure provided by the first embodiment of the present invention.

[0044] Figure 5 It is a radial cross-sectional view of the filter channel of the filter provided by the first embodiment of the present invention.

[0045] Figure 6 It is a partial structural diagram of the light source system provided by the first embodiment of the present invention.

[0046] Figure 7 2 is a flow chart of an extreme ultraviolet light output method provided by the second embodiment of the present invention.

[0047] Description of the accompanying drawings:

[0048] 10. Light source system;

[0049] 1. Cavity; 2. Pinch device; 3. Collection device; 4. Filter device;

[0050] 11. Transition zone; 12. Protection zone; 21. Transmitter; 22. Circuit assembly; 31. Hollow channel; 41. Filter channel; 42. Filter; 43. Filter sheet;

[0051] 111, first air inlet pipe; 121, second air inlet pipe; 122, air outlet pipe; 210, main body; 211, central channel; 212, first magnetic core; 213, second magnetic core; 214, outer channel; 215, plasma circuit; 216, protective element; 221, energy supply circuit; 222, first coupling unit; 223, magnetic pulse compression circuit; 224, second coupling unit;

[0052] A. Ablated area; B. Non-ionized insulating layer. [Specific implementation method]

[0053] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and implementation examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0054] In the embodiments provided herein, it should be understood that "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should also be understood that determining B based on A does not mean determining B based solely on A; B can also be determined based on A and / or other information.

[0055] It should be understood that references to "one embodiment" or "an embodiment" throughout this specification mean that specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present invention. Therefore, the appearance of "in one embodiment" or "in an embodiment" throughout this specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Those skilled in the art should also be aware that the embodiments described in this specification are all optional embodiments, and the actions and modules involved are not necessarily required for the present invention.

[0056] In various embodiments of the present invention, it should be understood that the size of the serial numbers of the above-mentioned processes does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0057] The flow charts and block diagrams in the accompanying drawings of the present invention illustrate the possible implementation architecture, functions and operations of the system, method and computer program product according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, program segment or a part of code, and the module, program segment or a part of code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementation schemes, the functions marked in the box can also occur in a different order than those marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which is determined based on the functions involved. It should be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0058] As one of the key pillars of the integrated circuit industry, photolithography machines provide the primary technical support for the development of the entire semiconductor industry. With the advancement of photolithography technology, extreme ultraviolet (EUV) lithography has become a consensus within the semiconductor industry. Electrodeless pinch devices can be incorporated into light source systems. As a potential EUV generation mechanism, EUV light sources using Z-pinch technology have lower discharge device requirements compared to other EUV generation mechanisms and offer higher spatial and temporal stability.

[0059] Z-Pinch is the self-pinching effect of a ring-shaped plasma loop toward its center due to the Lorentz force generated by a strong current perpendicular to the plane of the ring. The working process of the electrodeless pinch device is that the power system of the electrodeless pinch device generates high-frequency pulses, supplies energy to the xenon (Xe) gas through the coupling unit to generate plasma and form a loop in the vacuum chamber of the light source system. At this time, the magnetic field generated in the loop causes the plasma to pinch toward the axis, resulting in intensified collisions between particles and the production of high-valence Xe 10+ The ions eventually radiate EUV through the central hole on the emitting element in the pinch device.

[0060] However, the electrodeless pinch device is not stable in the process of radiating extreme ultraviolet light. There are two main problems: the first is that the main material of the emitting device inside the pinch device is copper. When the EUV is radiated on the central channel of the emitting device, the direction of current flow in the central channel always flows in the direction of the minimum impedance value. In the process of the plasma loop forming a pinch to produce extreme ultraviolet light, part of the electrical energy will be consumed by the copper structure through arc discharge and ablate the copper structure, thereby causing an arc between the plasma and the emitting device during the extreme ultraviolet light generation process, resulting in a break in the plasma loop, and causing the extreme ultraviolet light generation process to have poor stability. The second is that the radiated EUV usually needs to pass through a filtering device to filter the debris it carries, but the high-energy plasma in the debris will corrode the filtering device, seriously restricting the light collection efficiency. In order to protect the filtering device, a protective gas is usually used to protect the filtering device. Because the gas pressure changes with the electric pulse during the plasma pinching process, when the xenon gas near the central hole of the launch device is consumed, the protective gas may enter the pinching point due to the pressure change and react with the plasma, reducing the plasma density, and ultimately leading to a decrease in radiation power, resulting in poor stability of the EUV light formation process.

[0061] To solve the above technical problems, please refer to Figure 1A first embodiment of the present invention provides a light source system 10 for outputting extreme ultraviolet light. Light source system 10 includes a hollow cavity 1, and a pinching device 2, a collecting device 3, and a filtering device 4 disposed within cavity 1. The pinching device 2 includes an emitting device 21 and a circuit assembly 22. The emitting device 21 has a central aperture 211, and the output end of the circuit assembly 22 is disposed near central aperture 211. The collecting device 3 is disposed between the emitting device 21 and the filtering device 4. The side of the collecting device 3 proximate to the emitting device 21 defines a transition zone 11, and the side of the collecting device 3 distal to the emitting device 21 defines a protection zone 12. The collecting device 3 defines a hollow channel 31 corresponding to central aperture 211, and the filtering device 4 defines a filtering channel 41 corresponding to hollow channel 31. It should be understood that the interior of cavity 1 is sealed, and gas can flow into cavity 1. The collecting device 3 divides cavity 1 on the side of the emitting device 21 proximate to the collecting device 3 into a transition zone 11 and a protection zone 12, and the hollow channel 31 connects the transition zone 11 and the protection zone 12.

[0062] Specifically, a first gas and a second gas can flow into the transition zone 11. Ionization of the first gas at the output of the circuit assembly 22 generates plasma that can be pinched at the central channel 211 to form extreme ultraviolet light. As the extreme ultraviolet light is sequentially output through the central channel 211, the hollow channel 31, and the filter channel 41, it should be noted that the second gas itself can protect the surface of the emitting device 21. Furthermore, the ions generated by the ionization of the second gas at the output of the circuit assembly 22 can also protect the surface of the emitting device 21.

[0063] It can be understood that the main material of the emitting device 21 is copper, and the first gas is xenon. After the xenon is ionized by the circuit component 22, a large amount of plasma can be generated, and the circuit component 22 will also generate a strong current pulse, so that the plasma forms a ring-shaped plasma loop 215. Under the continuous action of the strong current pulse, the loop is pinched at the pinch point and radiates extreme ultraviolet light. It should be noted that the pinch point is usually in the central channel 211. During the radiation of extreme ultraviolet light, since the flow direction of the current always flows in the direction of the minimum impedance value, when the current passes through the central channel 211, part of the current will be discharged through arc light, causing the copper structure on the emitting device 21 to be ablated, resulting in an arc between the plasma and the emitting device 21 during the generation of extreme ultraviolet light, resulting in a break in the plasma loop, which in turn causes the problem of poor stability in the formation process of extreme ultraviolet light.

[0064] For example, see also Figure 2a and Figure 2b , ablation area A( Figure 2a and Figure 2bThe area in the oval frame is closer to the central channel 211, and the material in the ablation area A is a copper structure. During the EUV irradiation process, the arc discharge generated by the plasma in the central channel 211 is as follows: Figure 2a The plasma flow direction in Figure 2a As shown in the direction of the arrow in the middle, the arc discharge generated by the plasma will ablate the ablation area A, thereby destroying the launch device 21, and the plasma will flow from the ablation area A along the surface of the launch device 21. In this embodiment, the chamber can be divided into two areas, wherein the second gas can be introduced into the transition area 11. Specifically, the second gas is helium. It should be noted that at the beginning of the plasma loop pinch, since the ionization energy at the central channel 211 is not high, the helium mainly exists in the form of helium atoms. The helium atoms provide a non-ionized insulating layer B ( Figure 2b The area within the dotted rectangular box is used to protect the hole wall from the arc discharge generated by the plasma during the radiation of extreme ultraviolet light. It should be noted that the ionization energy of helium is 24.6eV, and the ionization energy of xenon is 12.13eV or 21.2eV. Therefore, when ionizing xenon, its ionization energy is not enough to ionize helium, that is, in the incompletely ionized xenon plasma, most of the helium will remain as neutral atoms. Specifically, when helium is rushed in, since the ionization of helium is related to time, within the pinching time (less than 1 microsecond), there are not enough helium atoms to be ionized. After the helium is filled into the transition zone 11, the helium contacts the launch device 21 and adheres to the surface of the launch device 21 to form a non-ionized insulating layer B to protect the hole wall from the influence of the plasma. As shown Figure 2b The plasma flow direction in Figure 2b As shown in the direction of the arrow in the middle, the plasma is blocked by the non-ionized insulating layer and does not flow along the surface of the emitting device 21. When the xenon atoms in the xenon gas are ionized into xenon ions (Xe 10+ ), at this time, the ionization energy near the pinch point is higher. Helium atoms begin to be ionized into helium ions. And because the atomic mass of helium (He=4) is smaller than the atomic mass of xenon (Xe=131). Therefore, even if there are helium ions in the pinch, it will not affect the dynamics of the pinch. The non-ionized insulating layer formed by it will still protect the launch device 21. Furthermore, since helium gas will continue to flow into the transition zone 11, the non-ionized insulating layer B will continue to be composed of a mixture of helium atoms and helium ions after the helium atoms begin to be ionized. Whether it is helium atoms or helium ions, the non-ionized insulating layer formed by them has high breakdown resistance, that is, a very high voltage is required to break it down. Then, the surface of the launch device 21 is protected to avoid damage to it by plasma arc discharge, which causes the problem of poor stability in the extreme ultraviolet light formation process.

[0065] It should be noted that the aforementioned process of protecting the surface of the emitter 21 with the second gas consists of two stages. Stage one: After the second gas enters the transition zone 11, it directly forms a non-ionizing insulating layer on the surface of the emitter 21, thereby protecting the emitter surface. Stage two: As the second gas is ionized and produces ions, the partially ionized second gas carries these ions with it to protect the emitter surface. Because the second gas is constantly replenished, it is never completely consumed.

[0066] In addition, in the prior art, all internal components and gases are usually mixed in one area. A protective gas is introduced to protect the filter device in the area, and if the protective gas enters the central channel, it will react with the plasma to reduce the plasma density. In this embodiment, there are two areas, in which the first gas and the second gas are mainly introduced into the transition zone 11, that is, xenon and helium are introduced. And the protective gas is mainly introduced into the protection zone 12. It should be understood that the first gas and the second gas are continuously introduced into the transition zone 11 in this embodiment, and the air pressure in the transition zone 11 is greater than the air pressure in the protection zone 12, so that the protective gas in the protection zone 12 will not flow into the transition zone 11, that is, the reaction between the protective gas and the plasma is avoided. It should be understood that this embodiment innovatively sets up two gas introduction areas, wherein helium can be introduced into the transition zone 11 to form a non-ionized insulating layer on the surface of the launch device 21 and thus protect the launch device 21, while the protection zone 12 is used to introduce protective gas separately. Since the gas pressure in the transition zone 11 is greater than that in the protection zone 12, the reaction between the protective gas and the plasma is avoided, the radiation power is avoided from being reduced, and the stability of the extreme ultraviolet light formation process is improved.

[0067] Furthermore, please combine Figure 1 and Figure 3 The transmitting device 21 includes a hollow main body 210, a first magnetic core 212 and a second magnetic core 213. The circuit component 22 is at least partially accommodated inside the main body 210. The main body 210 is provided with a central hole 211 along the axial direction of its central axis, and a plurality of outer holes 214 are provided in the circumferential direction around its central axis. There is a gap between the outer holes 214 and the central hole 211. The first magnetic core 212 and the second magnetic core 213 are both arranged inside the main body 210. The first magnetic core 212 is arranged between the central hole 211 and the outer hole 214, and the second magnetic core 213 is arranged on the outside of the outer hole 214 away from the central hole 211.

[0068] As will be appreciated, the first magnetic core 212 and the second magnetic core 213 are annular magnetic cores. The annular magnetic core can be used to focus the magnetic field within the launch device 21. During plasma generation, the distribution of the magnetic field is crucial for plasma stability and shape control. By designing an appropriate magnetic field, the plasma can maintain the desired shape and ensure stability throughout the launch process. The first magnetic core 212 functions like a transformer, generating mutual induction with the plasma circuit 215. The second magnetic core 213 is a soft magnetic element on a magnetic switch. It should be noted that the outer channel 214 is non-conductive, while the central channel 211 is conductive. It should be understood that if the outer channel 214 were conductive, the current generated by the circuit assembly 22 would not flow through the central channel 211, but would instead flow directly through the outer channel 214. However, since the outer channel 214 is non-conductive and the central channel 211 is conductive, the current can ionize the xenon gas to generate plasma. The high current pulses generated by the circuit assembly 22 cause the plasma to form a plasma circuit that passes through the central channel 211 and the outer channel 214 in sequence. Under the continuous action of high current pulses, the plasma loop can pinch at the pinch point and radiate extreme ultraviolet light. The process of radiating extreme ultraviolet light is simple and produces less particle fragments.

[0069] Further, see Figure 4 The circuit component 22 includes an energy supply circuit 221, a first coupling unit 222, a magnetic pulse compression circuit 223 and a second coupling unit 224; the input end of the first coupling unit 222 is connected to the output end of the energy supply circuit 221, and its output end, the magnetic pulse compression circuit 223 and the input end of the second coupling unit 224 are connected in sequence, and the output end of the second coupling unit 224 is the output end of the circuit component 22.

[0070] It should be understood that the energy supply circuit 221 is used to provide current and voltage, and the current and voltage are coupled through the first coupling unit 222 and then transmitted to the magnetic pulse compression circuit 223 to generate a strong current pulse. The plasma generated by the ionization of the first gas forms a plasma loop 215 that passes through the central channel 211 and the outer channel 214 in sequence based on the strong current pulse. That is, the energy generated by the pinching device can be transferred to the plasma in an inductively coupled manner through the second coupling unit 224 to form a plasma ring. The plasma loop 215 forms an output extreme ultraviolet light under the continuous pinching of the strong current pulse. Specifically, the plasma density at the central channel 211 is 10 18 cm -3 ~10 19 cm -3 Among them, the magnetic pulse compression circuit 223 can implement multi-level pulses on current and voltage, which will produce pulses with both high amplitude and wide pulse width, helping to increase the number of plasma pinches and thus obtain higher-power extreme ultraviolet light.

[0071] Further, please combine Figure 1 and Figure 2b The launch device 21 also includes a protective member 216. The protective member 216 is arranged on the inner wall surface of the central channel 211 corresponding to the output end of the circuit component 22. The protective member 216 is made of a high-temperature resistant material. Exemplarily, the material of the protective member 216 is silicon carbide (SiC), because the pinch point is inside the central channel 211. Exemplarily, the energy radiated by the plasma at the central channel 211 is 20eV to 40eV. That is, the plasma circuit 215 will generate high temperature when pinched, and silicon carbide has the function of heat insulation protection. Then, the protective member 216 attached to the inner wall surface of the central channel 211 can protect the inner wall surface of the central channel 211, prevent the inner wall surface of the central channel 211 from being damaged by the high-temperature plasma, and improve the durability of the device. In addition, avoiding ablation of the inner wall surface of the central channel 211 helps to maintain the stability of the launch device 21 and ensure the consistency of its performance during long-term operation.

[0072] Furthermore, a hollow channel 31 is provided on the collecting device 3 corresponding to the central channel 211. The main function of the collecting device 3 is to facilitate the extreme ultraviolet light radiated from the central channel 211 to be emitted to the filtering device 4 through the hollow channel 31. After the extreme ultraviolet light is excited by the pinch point, the beam of the extreme ultraviolet light itself has a beam angle. Therefore, according to the distance from the collecting device 3 to the emitting device 21 and the angle of the beam angle, the shape of the hollow channel 31 can be set specifically so that the extreme ultraviolet light can pass through the hollow channel 31 unobstructed. Figure 1 As shown, due to the beam angle of the extreme ultraviolet light, the cross-sectional shape of the hollow channel 31 is wedge-shaped, so that the extreme ultraviolet light can pass through the hollow channel 31 and be emitted to the filtering device 4 .

[0073] Furthermore, please combine Figure 1 and Figure 5 Filter 42 is provided within filtering channel 41, corresponding to the EUV light formed by the pinch at central channel 211. It should be understood that the EUV light emitted from collection device 3 may also contain some plasma debris. This plasma debris and impurities may adhere to the surface of optical components, affecting the quality of the output light. Filter 42 within filtering device 4 removes the effects of these debris and impurities, ensuring high-quality EUV light output.

[0074] Specifically, the filter 42 includes several filter plates 43, which are arranged in the filter channel 41, and the length direction of the filter plates 43 is parallel to the axial direction of the filter channel 41. It should be understood that after the extreme ultraviolet light passes through the hollow channel 31, it needs to pass through the filter channel 41 before it can be emitted into the protection zone 12. The filter plates 43 cannot block the light. Furthermore, the length direction of the filter plates 43 is parallel to the axial direction of the filter channel 41, that is, there are gaps between adjacent filter plates 43 for the extreme ultraviolet light to pass through. When the extreme ultraviolet light passes through the gaps, the debris it carries will come into contact with the surface of the filter plates 43. It should be noted that the debris mainly includes xenon ions, electrons and neutral atoms. Specifically, the neutral atoms are xenon atoms, nitrogen atoms or helium atoms. The debris carried by the extreme ultraviolet light will be introduced into the filter plates 43 and thus filtered out.

[0075] Optionally, the filter sheet 43 can be combined in various forms. Please refer to the figure. Figure 5 The cross-sectional view of the filter 42 along the radial direction of the filter channel 41 is shown. Figure 5 The filter 42 (shown in the shaded area) can be in a strip, honeycomb, annular, or coaxial shape. Gaps are left between adjacent filter plates 43 in the filter 42 to allow the EUV light to pass through. It should be noted that the cross-sections of the filter 42 described above are only a few possible implementations. The cross-section of the filter 42 can also be irregular, and the specific form is not limited, but gaps must be left to allow the EUV light to pass through.

[0076] Specifically, please combine Figure 1 and Figure 6 , the air pressure in the transition zone 11 is greater than the air pressure in the protection zone 12. A third gas is provided in the protection zone 12, and the third gas is used to protect the filter 42. It should be understood that after the nitrogen is introduced into the protection zone 12, a nitrogen protection environment can be created for the filter device 4 in the protection zone 12. When the extreme ultraviolet light enters the protection zone 12 through the hollow channel 31, the nitrogen is bombarded by the high-energy particles in the debris into a NN structure. Specifically, the NN structure is negatively charged and has the characteristics of a cation. The NN structure absorbs and consumes electrons, which can protect the filter 42 in the filter device 4 and prevent the high-energy particles in the debris from corroding the filter device 4 and damaging the filter device 4. As a result, the debris can be output together with the extreme ultraviolet light through the filter channel 41 of the filter device 4, thereby causing the problem of poor light collection efficiency.

[0077] Furthermore, the gas pressure within the transition zone 11 is greater than the gas pressure within the protection zone 12. It should be understood that, during the plasma pinch process, xenon gas introduced into the transition zone 11 enters the ionization zone of the central channel 211 and is ionized into plasma. Therefore, the gas pressure within the transition zone 11 varies with the electrical pulse. Therefore, when the xenon gas near the central hole of the emitter 21 is consumed, if the gas pressure within the transition zone 11 is lower than that of the protection zone 12, nitrogen gas may enter the pinch point due to the pressure change and react with the plasma, reducing the plasma density and ultimately reducing the radiation power, resulting in poor stability in the EUV light generation process. In this embodiment, by limiting the gas pressure within the transition zone 11 to be greater than that of the protection zone 12, nitrogen gas within the protection zone 12 cannot enter the transition zone 11 through the hollow channel 31, and therefore cannot enter the central channel 211 of the emitter 21. This prevents the plasma from reacting with the nitrogen gas when generating extreme ultraviolet light, thereby ensuring the plasma density and ensuring that the emitted extreme ultraviolet light has a higher radiation power.

[0078] For details, please refer to Figure 1 and Figure 6 The transition zone 11 is provided with a first air inlet pipe 111 for the first gas and the second gas to enter, and the protection zone 12 is provided with a second air inlet pipe 121 for the third gas to enter, and an air outlet pipe 122 for the gas to be discharged. It should be understood that xenon and helium can be introduced into the transition zone 11 through the first air inlet pipe 111. Specifically, the introduction path of xenon gas can be referred to in Figure 6 The dotted arrow in the figure. For example, the xenon gas flow rate introduced into the first inlet pipe can be 5 to 30 sccm, and the gas pressure can be 50 to 500 mtorr. After the xenon gas enters the central channel 211 of the emission device 21 from the transition zone 11 and is ionized by the circuit component 22, a large amount of plasma is generated. After the pulse action, the plasma forms a loop, and the magnetic field generated by itself pinches to produce a high-temperature, high-density plasma group (mainly Xe 10+ The final transition radiation produces 13.5nm±2% extreme ultraviolet light. Figure 6 As shown in the dotted solid arrow in the figure, nitrogen is introduced into the transition zone 11 from the second air inlet pipe 121 in the transition zone 11 to protect the filter device 4 in the transition zone 11. It should be noted that since the NN structure formed by nitrogen mainly absorbs and consumes the electrons of the debris, the nitrogen mainly forms a protective layer on the side of the filter device 4 close to the collection device 3. Furthermore, the nitrogen can also form a protective layer on the side of the filter device 4 away from the collection device 3. Therefore, nitrogen can create a protective environment for the entire filter device 4, thereby improving the protection effect on the filter device 4. Specifically, the entry path of helium can be found in Figure 6As shown by the dotted short-dashed arrow in the figure, after helium is introduced into the transition zone 11, part of the helium can form a non-ionized insulating layer on the surface of the launch device 21 to protect the launch device 21. However, since the air pressure in the transition zone 11 is greater than the air pressure in the protection zone 12. For example, the gas flow rate of helium can be 80 to 400 sccm. The gas flow rate of helium can be 1 to 5 times that of nitrogen. As a result, part of the helium in the transition zone 11 will enter the protection zone 12 through the hollow channel 31 and be discharged from the protection zone 12 together with the nitrogen through the gas outlet pipe 122.

[0079] It should be noted that the xenon gas in the transition zone 11 may also enter the protection zone 12 through the hollow channel 31, but the designer expects that more xenon gas will enter the central channel 211 and be ionized into plasma. Therefore, the number of first air inlet pipes 111 can be set to at least two, and xenon gas and helium gas can be introduced into the transition zone 11 through different first air inlet pipes 111. And it can be ensured that the pipe for xenon gas to enter is closer to the emission device 21 to ensure that xenon gas can be used to ionize into plasma to the maximum extent. Optionally, the number of first air inlet pipes 111 can also be one. At this time, xenon gas and helium gas need to be introduced into the transition zone 11 through the same first air inlet pipe 111. That is, there is no restriction on whether xenon gas and helium gas are introduced through the same pipe or through different pipes.

[0080] Furthermore, in this embodiment, helium can form a non-ionized insulating layer to protect the wall of the central channel 211 from the arc discharge generated by the plasma during the radiation of extreme ultraviolet light. And nitrogen can form a NN structure, absorb and consume the electrons of the debris, and protect the filter device 4. Therefore, the extreme ultraviolet light emitted through the filter channel 41 in this embodiment has better light source stability than the extreme ultraviolet light radiated by the prior art. Specifically, the use of the light source system 10 in this embodiment can improve the stability of the extreme ultraviolet light during the generation process by 70%.

[0081] To solve the above technical problems, please refer to Figure 7 The second embodiment of the present invention further provides an extreme ultraviolet light output method for protecting the emission device in the above light source system, the method comprising:

[0082] S1, providing a first gas, ionizing the first gas to generate plasma, and applying a strong current pulse to the plasma to form a plasma loop;

[0083] S2, continuously applying a strong current pulse to the plasma loop to generate extreme ultraviolet light and debris at the output end of the emission device;

[0084] S3, providing a second gas to protect the surface of the emitting device by the second gas;

[0085] S4, after the extreme ultraviolet light and debris are collected and filtered, the extreme ultraviolet light is output.

[0086] It is understandable that in this embodiment, a first gas can be provided first, specifically, the first gas is xenon. After the xenon gas is ionized, a plasma can be generated. Further, after a strong current pulse is applied to the plasma, a plasma loop can be formed. The plasma loop can form extreme ultraviolet light at the output end of the emission device under the continuous pinching of the strong current pulse. It should be understood that in the process of forming extreme ultraviolet light, debris will also be generated, where the debris includes plasma, high-energy electrons, cations, and neutral atoms ejected during the pinching process. Further, a second gas is provided, and the second gas can be helium. Based on the fact that helium can protect the surface of the emission device, the helium adheres to the surface of the emission device to form a non-ionized insulating layer to protect the surface of the emission device from the arc discharge generated by the plasma during the formation of extreme ultraviolet light. Alternatively, if helium ions are generated after helium is ionized, the atomic mass of helium (He=4) is smaller than that of xenon (Xe=131). Therefore, even if helium ions exist in the pinch, it does not affect the dynamics of the pinch. The non-ionizing insulating layer it forms will still protect the emitting device, preventing arcing between the plasma and the emitting device during the generation of extreme ultraviolet light, which may cause the plasma loop to break and further cause poor stability in the extreme ultraviolet light generation process.

[0087] Furthermore, after collecting and filtering the EUV light and debris, the EUV light is outputted, including:

[0088] S41, collects EUV light and debris;

[0089] S42, filtering the extreme ultraviolet light and the debris to filter out the debris;

[0090] S43, introducing a third gas during filtering, and outputting extreme ultraviolet light after filtering.

[0091] It is understandable that during the collection and processing, the extreme ultraviolet light will carry debris. Therefore, the extreme ultraviolet light and plasma can be filtered, and the plasma can be filtered out. At the same time, a third gas can be introduced during the filtration. Specifically, the third gas is nitrogen. It should be understood that the nitrogen is bombarded by the high-energy particles in the debris into a NN structure. The NN structure is negatively charged and has the characteristics of a cation. The NN structure absorbs and consumes electrons. During the filtration process, the device implementing the filtration process can be protected to prevent the high-energy particles in the debris from corroding the filtration device and damaging the filtration device. Specifically, after filtration, an extreme ultraviolet light of 13.5nm±2% can be output.

[0092] Specifically, the first gas is xenon, and its main function is to generate a large amount of plasma after being ionized. When the first gas is provided, the gas flow rate thereof can be 5 to 30 sccm. The gas pressure can be 50 to 500 mtorr. The second gas is helium, and its main function is to form a non-ionized insulating layer on the surface of the launch device to protect the launch device. When the second gas is provided, the gas flow rate thereof can be 80 to 400 sccm. The third gas is nitrogen, and its main function is to be bombarded by high-energy particles in the debris into a NN structure. The NN structure absorbs and consumes electrons, and can protect the device implementing the filtering process during the filtering process, thereby preventing high-energy particles in the debris from corroding the filtering device. When the second gas is provided, the gas flow rate of the third gas can be 15 to 80 sccm.

[0093] It should be noted that the method used in this embodiment can form a non-ionizing insulating layer to protect the pore wall of the central channel from the arc discharge generated by the plasma during the emission of extreme ultraviolet light. It can also prevent debris carried by the extreme ultraviolet light from damaging the filter device during the filtering process, thus greatly protecting the emission device and the filter device, so that the extreme ultraviolet light emitted after passing through the filter device has better light source stability.

[0094] Compared with the prior art, the light source system and extreme ultraviolet light output method provided by the present invention have the following beneficial effects:

[0095] 1. An embodiment of the present invention provides a light source system for outputting extreme ultraviolet light. The light source system includes a pinching device, a collecting device, and a filtering device. The pinching device includes an emitting device and a circuit assembly. The emitting device has a central hole, and the output end of the circuit assembly is located near the central hole.

[0096] The collecting device is arranged between the emitting device and the filtering device. The side of the collecting device close to the emitting device defines a transition zone, and the side of the collecting device away from the emitting device defines a protection zone. The collecting device has a hollow channel corresponding to the central channel, and the filtering device has a filtering channel corresponding to the hollow channel.

[0097] A first gas and a second gas are introduced into the transition zone. Ionization of the first gas by the output terminal of the circuit assembly generates plasma that is pinched at the central channel to form EUV light. As the EUV light sequentially passes through the central channel, the hollow channel, and the filter channel, the second gas protects the surface of the emission device. In this embodiment, two regions are provided. Helium gas introduced into the transition zone forms a non-ionizing insulating layer to protect the emission device, preventing damage from plasma arc discharge, which could lead to poor stability in the EUV light generation process.

[0098] 2. The transmitting device of the embodiment of the present invention includes a hollow main body, a first magnetic core and a second magnetic core. The main body is provided with a central hole in the axial direction of its central axis, and a plurality of outer holes in the circumferential direction around its central axis. There is a gap between the outer holes and the central hole. The first magnetic core and the second magnetic core are both arranged inside the main body. The first magnetic core is arranged between the central hole and the outer hole, and the second magnetic core is arranged on the outside of the outer hole away from the central hole. The first magnetic core can generate mutual induction with the plasma circuit. The second magnetic core is soft magnetic and can be used as a switch. After the plasma forms a plasma circuit that passes through the central hole and the outer hole in sequence, it can be pinched at the pinch point and radiate extreme ultraviolet light. The process of radiating extreme ultraviolet light is simple and produces less particle fragments.

[0099] 3. A circuit assembly according to an embodiment of the present invention includes an energy supply circuit, a first coupling unit, a magnetic pulse compression circuit, and a second coupling unit. The input of the first coupling unit is connected to the output of the energy supply circuit, and the output of the first coupling unit, the magnetic pulse compression circuit, and the input of the second coupling unit are sequentially connected. The output of the second coupling unit serves as the output of the circuit assembly.

[0100] The energy supply circuit provides current and voltage, which are coupled through a first coupling unit and then transmitted to the magnetic pulse compression circuit to generate a high-current pulse. The ionized first gas generates a high-current pulse that applies to the plasma, forming a plasma loop that sequentially passes through the central and outer channels. The plasma loop is continuously pinched by the high-current pulse to produce output extreme ultraviolet light. The magnetic pulse compression circuit can perform multi-stage pulse compression on the current and voltage, producing pulses with both high amplitude and wide pulse width, which helps increase the number of plasma pinches and thus obtain higher-power extreme ultraviolet light.

[0101] 4. The transmitter device of this embodiment of the present invention further includes a protective member disposed on the inner wall surface of the central channel, corresponding to the output terminal of the circuit assembly. The protective member provides thermal insulation. Furthermore, the protective member, when attached to the inner wall surface of the central channel, protects the inner wall surface from damage by the high-temperature plasma, thereby improving the durability of the device.

[0102] 5. In the embodiment of the present invention, a filter is provided in the filter channel corresponding to the extreme ultraviolet light formed by the pinch at the central channel. The filter can filter out the influence of debris and impurities, ensuring the output extreme ultraviolet light of good quality.

[0103] 6. The filter of an embodiment of the present invention includes several filter plates, which are arranged in a filter channel, and the length direction of the filter plates is parallel to the axial direction of the filter channel, so that gaps are left between adjacent filter plates in the filter for extreme ultraviolet light to pass through, thereby avoiding the problem of the filter plates blocking the extreme ultraviolet light and causing the extreme ultraviolet light to be unable to be output.

[0104] 7. In the embodiment of the present invention, a third gas is introduced into the protected area to protect the filter. A first inlet conduit for the first and / or second gas is provided within the transition zone, while a second inlet conduit for the third gas is provided within the protected area, along with an outlet conduit for the third gas. The third gas can be bombarded by high-energy particles to form a negatively charged NN structure, which exhibits cationic properties. The NN structure absorbs and consumes electrons, protecting the filter within the filtration device and preventing erosion by high-energy particles in the debris.

[0105] 8. An embodiment of the present invention also provides an extreme ultraviolet light output method, which has the same beneficial effects as the above-mentioned light source system and will not be described in detail here.

[0106] The above is a detailed introduction to a light source system and an extreme ultraviolet light output method disclosed in an embodiment of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention. Any modifications, equivalent replacements and improvements made within the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A light source system for outputting extreme ultraviolet light, characterized in that: The light source system includes a pinching device, a collecting device and a filtering device; The pinch device includes a launch device and a circuit assembly, the launch device is provided with a central hole, and the output end of the circuit assembly is arranged close to the central hole; The collecting device is disposed between the emitting device and the filtering device. The collecting device defines a transition zone on a side close to the emitting device, and defines a protection zone on a side away from the emitting device. The collecting device defines a hollow channel corresponding to the central channel, and the filtering device defines a filtering channel corresponding to the hollow channel. A first gas and a second gas are introduced into the transition zone; the first gas is ionized by the output end of the circuit component to generate plasma that is pinched at the central channel to form extreme ultraviolet light; when the extreme ultraviolet light is output through the central channel, the hollow channel and the filter channel in sequence, the second gas is used to protect the surface of the emitting device.

2. The light source system according to claim 1, wherein: The transmitting device includes a hollow main body, a first magnetic core and a second magnetic core. The circuit component is at least partially accommodated inside the main body. The main body is provided with a central hole in the axial direction of its central axis and a plurality of outer holes in the circumferential direction around its central axis. There is a gap between the outer holes and the central hole. The first magnetic core and the second magnetic core are both arranged inside the main body. The first magnetic core is arranged between the central hole and the outer holes, and the second magnetic core is arranged on the outside of the outer holes away from the central hole.

3. The light source system according to claim 2, wherein: The circuit assembly includes an energy supply circuit, a first coupling unit, a magnetic pulse compression circuit, and a second coupling unit; the input end of the first coupling unit is connected to the output end of the energy supply circuit, and the output end of the first coupling unit, the magnetic pulse compression circuit, and the input end of the second coupling unit are connected in sequence; the output end of the second coupling unit is the output end of the circuit assembly; The energy supply circuit is used to provide current and voltage, which are coupled through a first coupling unit and then transmitted to the magnetic pulse compression circuit to generate a high-current pulse. The first gas is ionized and a high-current pulse is applied to the plasma to form a plasma loop that passes through the central channel and the outer channel in sequence. The plasma loop forms output extreme ultraviolet light under the continuous pinching of the high-current pulse.

4. The light source system according to claim 1, wherein: The transmitting device further comprises a protective member, which is arranged on the inner wall surface of the central channel corresponding to the output end of the circuit component.

5. The light source system according to claim 1, wherein: A filter is provided in the filtering channel corresponding to the extreme ultraviolet light formed by the pinching at the central hole.

6. The light source system according to claim 5, wherein: The filter comprises a plurality of filter plates, which are arranged in the filter channel, and the length direction of the filter plates is parallel to the axial direction of the filter channel.

7. The light source system according to claim 5, wherein: A third gas is introduced into the protection zone, and the third gas is used to protect the filter; a first air inlet pipe for the first gas and / or the second gas is provided in the transition zone, and a second air inlet pipe for the third gas is provided in the protection zone, as well as an air outlet pipe for gas discharge.

8. An extreme ultraviolet light output method for protecting an emission device in a light source system according to any one of claims 1 to 7, characterized in that: The method comprises: providing a first gas, ionizing the first gas to generate plasma, and applying a strong current pulse to the plasma to form a plasma loop; continuously applying high current pulses to the plasma loop to generate extreme ultraviolet light and debris at an output of the emission device; providing a second gas to protect the surface of the emitting device through the second gas; After the extreme ultraviolet light and debris are collected, processed and filtered, the extreme ultraviolet light is output.

9. The method for outputting extreme ultraviolet light according to claim 8, wherein: After collecting and filtering the EUV light and debris, the EUV light is output as follows: Collecting extreme ultraviolet light and debris; The extreme ultraviolet light and debris are filtered to filter out the debris; A third gas is introduced during filtration, and extreme ultraviolet light is output after filtration.

10. The EUV light output method according to claim 8, wherein: The second gas is helium, the third gas is nitrogen, and the ratio of the flow rate of the helium gas to the flow rate of the nitrogen gas is in a range of 1-5.

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