Magnetic levitation potential well coagulation device and metal liquid droplet coagulation method

Abstract

The application relates to the technical field of extreme ultraviolet light generation, in particular to a magnetic levitation potential well coagulation device and a metal droplet coagulation method. The magnetic levitation potential well coagulation device comprises a magnetic potential well generator, a detection sensor and a controller. The magnetic potential well generator is arranged at the downstream of a metal droplet generator, and the magnetic potential well generator is configured to generate a magnetic potential well to generate a force on the metal droplets output by the metal droplet generator, and the force can reduce the movement speed of the metal droplets. The detection sensor is arranged at the downstream of the magnetic potential well generator, and the detection sensor can detect the size of the metal droplets. The detection sensor and the magnetic potential well generator are in communication connection with the controller, and the controller is configured to control the start, the stop and the adjustment of the strength of the magnetic potential well generator according to the detection result of the detection sensor. The metal droplet coagulation method can make the size of the metal droplets meet the generation requirements of extreme ultraviolet light when applied to the above-mentioned magnetic levitation potential well coagulation device.

Description

Technical Field

[0001] This invention relates to the field of extreme ultraviolet light generation technology, and in particular to a magnetic levitation potential well coagulation device and a method for metal droplet coagulation. Background Technology

[0002] As photolithography technology rapidly advances towards finer manufacturing processes, semiconductor manufacturing processes are now capable of producing semiconductor devices with increasingly finer feature sizes. To meet the demand for microfabrication with feature sizes of 32nm or smaller, it is desirable to develop an exposure device that will generate extreme ultraviolet light with a wavelength of approximately 13.5nm.

[0003] Materials containing elements such as xenon, lithium, or tin can be converted into a plasma state to emit extreme ultraviolet light. Typically, plasma is generated using lasers, where high-energy pulsed lasers bombard tin metal particles tens of micrometers in size (in the form of metal droplets, plates, strips, streams, or material clusters) to form the desired plasma that radiates extreme ultraviolet light.

[0004] Typically, when molten tin droplets pass through a cylindrical tube, the Plateau-Rayleigh instability occurs due to surface tension, causing the cylindrical droplets to spontaneously transform into spherical, monodisperse droplets. By using ultrasonic waves to generate perturbations and by utilizing different air pressures, parameters such as the emission frequency, size, and spacing of the molten tin droplets can be controlled. One design involves using a ring-shaped piezoelectric ceramic sleeve on the outlet tube of the molten tin droplet generator to directly apply ultrasonic waves to the droplets. However, various interference factors often affect the accuracy of the molten tin droplet size, resulting in droplets that do not meet the requirements for extreme ultraviolet (EUV) light generation, thus affecting the stability of the subsequent EUV generation process. Summary of the Invention

[0005] One objective of this invention is to provide a magnetic levitation potential trap condensation device that enables the size of metal droplets to meet the requirements for extreme ultraviolet light generation, improves the accuracy of metal droplet size, and ensures the stability of the extreme ultraviolet light generation process.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A magnetic levitation potential well coagulation device is provided, comprising:

[0008] A magnetic potential well generator is disposed downstream of a metal droplet generator and is configured to generate a magnetic potential well to exert a force on the metal droplets output by the metal droplet generator, the force being able to reduce the velocity of the metal droplets.

[0009] A detection sensor is disposed downstream of the magnetic potential trap generator, and the detection sensor is capable of detecting the size of the metal droplet;

[0010] The controller is communicatively connected to both the detection sensor and the magnetic potential trap generator. The controller is configured to control the start-up and shutdown of the magnetic potential trap generator and adjust the intensity of the magnetic potential trap based on the detection results of the detection sensor.

[0011] Optionally, the magnetic potential well generator includes a first coil and a second coil, which are coaxially spaced apart. The current direction in the first coil is opposite to the current direction in the second coil, and the current in the second coil is greater than the current in the first coil, so as to generate a magnetic potential well between the first coil and the second coil to generate the force on the metal droplet.

[0012] Optionally, the magnetic field generated by the magnetic potential trap generator is an alternating magnetic field to adjust the magnitude of the force.

[0013] Optionally, the detection sensor includes a laser emitter and a laser sensor, wherein the laser emitter is used to emit laser light toward the metal droplet, and the laser sensor is used to receive the laser light that is not blocked by the metal droplet.

[0014] Optionally, it also includes a vacuum chamber, in which both the magnetic potential trap generator and the detection sensor are disposed.

[0015] Optionally, it also includes the metal droplet generator, wherein the diameter of the metal droplets output by the metal droplet generator ranges from 0.1 micrometers to 10 micrometers;

[0016] And / or, the diameter of the metal droplets after condensation by the magnetic potential trap generator ranges from 10 micrometers to 100 micrometers.

[0017] Optionally, the device also includes the metal droplet generator, wherein the distance between any two adjacent metal droplets output by the metal droplet generator is greater than 100 micrometers.

[0018] Optionally, the device also includes the metal droplet generator, wherein the emission frequency of the metal droplet generator is in the range of 1kHz-10MHz.

[0019] Another objective of this invention is to provide a method for metal droplet agglomeration that enables the size of the metal droplets to meet the requirements for extreme ultraviolet light generation, improves the accuracy of the metal droplet size, and ensures the stability of the extreme ultraviolet light generation process.

[0020] To achieve this objective, the present invention adopts the following technical solution:

[0021] A method for metal droplet agglomeration is provided, applied to the aforementioned magnetic levitation potential well agglomeration device. The metal droplet agglomeration method includes the following steps:

[0022] The metal droplet generator outputs a series of spaced metal droplets. When the metal droplets pass through the magnetic potential trap generated by the magnetic potential trap generator, they are subjected to force and their speed decreases. The controller can control the magnetic potential trap generator to adjust the intensity of the magnetic potential trap so that the speed of the preceding metal droplets is lower than that of the following metal droplets, and the following metal droplets condense with the preceding metal droplets.

[0023] When the preset conditions are met, the controller controls the magnetic potential trap generator to adjust the intensity of the magnetic potential trap to reduce the movement speed of the next metal droplet, so as to prevent the next metal droplet from continuing to merge with the metal droplet in front.

[0024] Optionally, the preset conditions include: the detection sensor detects that the size of the agglomerated metal droplets meets the preset droplet size requirement, or the detection sensor detects the size of multiple metal droplets, and the controller calculates that the sum of the volumes of the multiple metal droplets meets the preset droplet volume requirement.

[0025] The beneficial effects of this invention are:

[0026] This invention provides a magnetic levitation potential well coalescing device, including a potential well generator, a detection sensor, and a controller. The potential well generator is located downstream of a metal droplet generator and is configured to generate a potential well to exert a force on the metal droplets output by the metal droplet generator, reducing their velocity. The detection sensor is also located downstream of the potential well generator and can detect the size of the metal droplets. Both the detection sensor and the potential well generator are communicatively connected to the controller, which is configured to control the activation and deactivation of the potential well generator and adjust the intensity of the potential well based on the detection results from the detection sensor. By reducing the velocity of the metal droplets through the potential well generated by the potential well generator, the velocity of preceding metal droplets is lower than that of subsequent metal droplets, allowing subsequent metal droplets to collide and coalesce with preceding metal droplets until the desired size of the droplets is achieved. Then, the potential well is used again to reduce the velocity of the next droplet to prevent further collisions and coalescing, thus obtaining a series of metal droplets of the desired size. Therefore, this magnetic levitation potential trap condensation device can make the size of the metal droplets meet the requirements for extreme ultraviolet light generation, improve the accuracy of the metal droplet size, and ensure the stability of the extreme ultraviolet light generation process.

[0027] This invention also provides a method for metal droplet agglomeration, applied to the aforementioned magnetic levitation potential well agglomeration device. The method includes the following steps: a metal droplet generator outputs a series of spaced metal droplets. When a metal droplet passes through a magnetic potential well generated by the magnetic potential well generator, it experiences a force and its speed decreases. A controller can control the magnetic potential well generator to adjust the strength of the magnetic potential well, so that the speed of the preceding metal droplet is lower than that of the following metal droplet, causing the following metal droplet to agglomerate with the preceding metal droplet. When a preset condition is met, the controller controls the magnetic potential well generator to adjust the strength of the magnetic potential well to reduce the speed of the next metal droplet, preventing the next metal droplet from continuing to agglomerate with the preceding metal droplet. Therefore, by applying this metal droplet agglomeration method to the aforementioned magnetic levitation potential well agglomeration device, the size of the metal droplets can meet the requirements for extreme ultraviolet light generation, improving the accuracy of the metal droplet size and ensuring the stability of the extreme ultraviolet light generation process. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the magnetic levitation potential well coagulation device provided in an embodiment of the present invention;

[0029] Figure 2 This is a partial structural schematic diagram of the magnetic potential well generator provided in an embodiment of the present invention.

[0030] In the picture:

[0031] 1. Magnetic potential trap generator; 11. First coil; 12. Second coil; 13. Power supply; 2. Metal droplet generator; 3. Controller; 4. Laser emitter; 5. Laser sensor; 6. Vacuum chamber; 7. Signal collector;

[0032] 100, Initial droplet; 200, Merged droplet; 300, Laser beam; 400, First current direction; 500, Second current direction; 600, First magnetic field line; 700, Second magnetic field line. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings, not all of them.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] like Figures 1-2 As shown, the magnetic levitation potential well coalescing device of this embodiment includes a magnetic potential well generator 1, a detection sensor, and a controller 3. The magnetic potential well generator 1 is located downstream of the metal droplet generator 2 and is configured to generate a magnetic potential well to exert a force on the metal droplets output by the metal droplet generator 2, thereby reducing the velocity of the metal droplets. The detection sensor is located downstream of the magnetic potential well generator 1 and is capable of detecting the size of the metal droplets. Both the detection sensor and the magnetic potential well generator 1 are communicatively connected to the controller 3, which is configured to control the activation and deactivation of the magnetic potential well generator 1 and adjust the intensity of the magnetic potential well based on the detection results from the detection sensor.

[0037] The metal droplet generator 2 outputs a series of metal droplets, while the magnetic potential trap generator 1 generates a magnetic potential trap that reduces the velocity of the passing metal droplets. By adjusting the strength of the magnetic potential trap, the velocity of the preceding metal droplets can be reduced more significantly, while the velocity of the following metal droplets can be reduced less or not at all, resulting in the velocity of the following metal droplets being greater than that of the preceding ones. This causes the following metal droplets to collide and coalesce with the preceding metal droplets. Following this principle, collisions and coalesces of two, three, four, or more droplets can be achieved until the size of the coalesced metal droplet meets the requirements. At this point, it is necessary to prevent the next droplet from colliding and coalescing with this coalesced droplet; that is, the velocity of the next droplet must be less than or equal to that of the coalesced droplet. This can be achieved by adjusting the strength of the magnetic potential trap, again reducing the velocity of the next droplet, thus preventing it from continuing to collide and coalesce with the preceding metal droplets. Furthermore, the next droplet can serve as the first initial droplet 100 of the next merged droplet 200. The aforementioned adjustment process of the magnetic potential trap is repeated to regulate the velocity of subsequent droplets, thus obtaining a second merged droplet 200. By continuously adjusting the intensity of the magnetic potential trap generated by the magnetic potential trap generator 1, a series of merged droplets 200, i.e., a series of metal droplets with the required size, can be obtained. Therefore, this magnetic levitation potential trap condensation device can ensure that the size of the metal droplets meets the requirements for extreme ultraviolet light generation, improving the accuracy of the metal droplet size and ensuring the stability of the extreme ultraviolet light generation process.

[0038] like Figure 2 As shown, optionally, the magnetic potential well generator 1 includes a first coil 11 and a second coil 12, which are coaxially arranged at a distance from each other. The current direction in the first coil 11 is opposite to the current direction in the second coil 12. The current direction in the first coil 11 is... Figure 2 The first current direction is 40°, and the current direction of the second coil 12 is... Figure 2 The direction of the second current in the middle is 50°. Figure 2 The first magnetic field line 600 in the diagram can characterize the magnetic field generated by the first coil 11. Figure 2The second magnetic field line 700 in the diagram represents the magnetic field generated by the second coil 12. Since the current in the second coil 12 is greater than the current in the first coil 11, a magnetomotive force trap is generated between the first coil 11 and the second coil 12, forming a concave magnetomotive force trap with a levitation effect. By coaxially aligning the first coil 11 and the second coil 12, with their axes aligned with the output port of the droplet generator, and with the first coil 11 closer to the droplet generator than the second coil 12, a force opposite to the direction of the metal droplet's velocity is generated on the droplet located on the axis, thus reducing the droplet's velocity. Furthermore, adjusting the current in the first coil 11 and the second coil 12 adjusts the strength of the magnetomotive force trap, allowing for precise control of the velocity of each metal droplet.

[0039] Optionally, the magnetic field generated by the magnetomotive force well generator 1 is an alternating magnetic field to adjust the magnitude of the force. Optionally, the magnetomotive force well generator 1 also includes a power supply 13, which supplies power to the first coil 11 and the second coil 12. The specific method for adjusting the current in the coils is a conventional method and will not be described in detail here.

[0040] Optionally, the detection sensor includes a laser emitter 4 and a laser sensor 5. The laser emitter 4 emits laser light towards the metal droplet, and the laser sensor 5 receives the laser light that is not blocked by the metal droplet. The cross-sectional size of the droplet can be determined by the size of the blocked portion, and the size and volume of the droplet can be calculated based on the deformation law of the droplet at this velocity. It should be noted that the size of the laser beam 300 in the figure is the same as the size of the merged droplet 200, meaning that the laser beam 300 is completely blocked when the size of the merged droplet 200 meets the requirements. Of course, in other embodiments, the size of the laser beam 300 can be set to be larger to monitor the size and velocity of the droplet; no further limitations are imposed here.

[0041] Optionally, the magnetic levitation potential well condensation device also includes a vacuum chamber 6, in which the magnetic potential well generator 1 and the detection sensor are both located.

[0042] Optionally, the magnetic levitation potential trap condensation device further includes a metal droplet generator 2, wherein the diameter of the metal droplets output by the metal droplet generator 2 ranges from 0.1 micrometers to 10 micrometers. Optionally, the diameter of the metal droplets condensed by the magnetic potential trap generator 1 ranges from 10 micrometers to 100 micrometers to meet the requirements for subsequent extreme ultraviolet light generation.

[0043] Optionally, among the multiple metal droplets output by the metal droplet generator 2, the distance between any two adjacent metal droplets is greater than 100 micrometers, in order to facilitate the control of some droplet collisions and merging. Optionally, the emission frequency of the metal droplet generator 2 is in the range of 1kHz-10MHz, which ensures that adjacent droplets are at a suitable distance when the droplet movement speed is constant.

[0044] Optionally, the magnetic levitation potential well condensation device also includes a signal collector 7, which can collect the detection results of the detection sensor and transmit them to the controller 3. It should also be noted that the controller 3 is a PLC or other conventional controller 3, and its control principle will not be elaborated here.

[0045] Furthermore, the magnetic potential trap can reduce the spatial jitter of droplets and increase the spacing between adjacent metal droplets. Additionally, the magnetic potential trap has a correction function, causing droplets not located on the axes of the two coils to move towards and focus on the axes, according to... Figure 2 In terms of the display orientation, regardless of whether the droplet is located on the left, right, front or back of the axis before entering the magnetic potential trap, it will move to the axis of the two coils of the magnetic potential trap after passing through the magnetic potential trap, so that the metal droplets output by the device not only meet the requirements in size, but also have the same direction and speed of movement.

[0046] This embodiment also provides a method for metal droplet agglomeration, applied to the above-mentioned magnetic levitation potential well agglomeration device, the method comprising the following steps:

[0047] First, the metal droplet generator 2 outputs a series of spaced metal droplets. When the metal droplets pass through the magnetic potential trap generated by the magnetic potential trap generator 1, they are subjected to force and their speed decreases. The controller 3 can control the magnetic potential trap generator 1 to adjust the intensity of the magnetic potential trap so that the speed of the metal droplets in front is lower than that of the metal droplets behind, and the metal droplets behind collide and merge with the metal droplets in front.

[0048] Then, when the preset conditions are met, the controller 3 controls the magnetic potential trap generator 1 to adjust the intensity of the magnetic potential trap to reduce the speed of the next metal droplet, so as to prevent the next metal droplet from continuing to merge with the metal droplet in front.

[0049] Optionally, the preset conditions have two scenarios: one is that the detection sensor detects that the size of the agglomerated metal droplets meets the preset droplet size requirement. This scenario is suitable when the previous few droplets have collided and agglomerated, and the next droplet is either within the magnetic potential trap range or has not yet entered the magnetic potential trap range.

[0050] Another preset condition is that the detection sensor detects the size of multiple metal droplets, and the controller 3 calculates that the sum of the volumes of the multiple metal droplets meets the preset droplet volume requirement. That is, multiple droplets pass through the detection sensor in sequence, and may not have merged yet. They may merge immediately after passing the laser, or some may have already merged. The detection sensor detects the size of the multiple metal droplets separately, and calculates the sum of the volumes of the multiple metal droplets. If the calculated result is consistent with or slightly larger than the volume of a droplet of the preset size, it can be considered that the next droplet needs to be intercepted to prevent it from colliding and merging with the previous droplets. After the aforementioned multiple droplets pass through the magnetic potential trap, the velocity of the multiple droplets increases sequentially, and they will inevitably collide and merge. That is, at a certain position after passing the laser, a merged droplet 200 that meets the requirements will inevitably be obtained. It needs to be ensured that when the laser detects the last of the above multiple droplets, the next droplet is just within the magnetic potential trap range, or has not yet entered the magnetic potential trap range. At this time, the magnetic potential trap is enhanced, which can significantly reduce the speed of the next droplet, ensuring that it will not collide with the merged droplet 200 in front.

[0051] The aforementioned magnetic levitation potential trap agglomeration device, using the aforementioned metal droplet agglomeration method, can obtain a string of metal droplets, and the size of each metal droplet meets the requirements for extreme ultraviolet light generation, thereby improving the accuracy of metal droplet size and ensuring the stability of the extreme ultraviolet light generation process.

[0052] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A magnetic levitation potential well coagulation device, characterized in that, include: A magnetic potential well generator (1) is disposed downstream of a metal droplet generator (2), and the magnetic potential well generator (1) is configured to generate a magnetic potential well to exert a force on the metal droplets output by the metal droplet generator (2), the force being able to reduce the speed of the metal droplets. A detection sensor is disposed downstream of the magnetic potential trap generator (1), and the detection sensor is capable of detecting the size of the metal droplet; The controller (3) is connected in communication with the detection sensor and the magnetic potential trap generator (1). The controller (3) is configured to control the start-up and shutdown of the magnetic potential trap generator (1) and adjust the intensity of the magnetic potential trap according to the detection result of the detection sensor. The magnetic potential trap generator (1) includes a first coil (11) and a second coil (12), which are coaxially spaced apart. The current direction in the first coil (11) is opposite to the current direction in the second coil (12), and the current in the second coil (12) is greater than the current in the first coil (11), so as to generate a magnetic potential trap between the first coil (11) and the second coil (12) to generate the force on the metal droplet. The magnetic field generated by the magnetic potential trap generator (1) is an alternating magnetic field to adjust the magnitude of the force.

2. The magnetic levitation potential well coagulation device according to claim 1, characterized in that, The detection sensor includes a laser emitter (4) and a laser sensor (5). The laser emitter (4) is used to emit laser light into the metal droplet, and the laser sensor (5) is used to receive the laser light that is not blocked by the metal droplet.

3. The magnetic levitation potential well coagulation device according to claim 1, characterized in that, It also includes a vacuum chamber (6), in which the magnetic potential trap generator (1) and the detection sensor are both located.

4. The magnetic levitation potential well coagulation device according to claim 1, characterized in that, It also includes the metal droplet generator (2), wherein the diameter of the metal droplets output by the metal droplet generator (2) ranges from 0.1 micrometers to 10 micrometers; And / or, the diameter of the metal droplets after condensation by the magnetic potential trap generator (1) ranges from 10 micrometers to 100 micrometers.

5. The magnetic levitation potential well coagulation device according to claim 1, characterized in that, It also includes the metal droplet generator (2), wherein the distance between any two adjacent metal droplets output by the metal droplet generator (2) is greater than 100 micrometers.

6. The magnetic levitation potential well coagulation device according to claim 1, characterized in that, It also includes the metal droplet generator (2), the emission frequency of which is in the range of 1kHz-10MHz.

7. A method for the coalescence of liquid metal droplets, characterized in that, Applied to the magnetic levitation potential well coagulation device as described in any one of claims 1-6, the metal droplet coagulation method includes the following steps: The metal droplet generator (2) outputs a series of spaced metal droplets. When the metal droplets pass through the magnetic potential trap generated by the magnetic potential trap generator (1), they are subjected to force and their speed decreases. The controller (3) can control the magnetic potential trap generator (1) to adjust the intensity of the magnetic potential trap so that the speed of the preceding metal droplet is lower than the speed of the following metal droplet, and the following metal droplet condenses with the preceding metal droplet. When the preset conditions are met, the controller (3) controls the magnetic potential trap generator (1) to adjust the intensity of the magnetic potential trap to reduce the movement speed of the next metal droplet, so as to prevent the next metal droplet from continuing to condense with the metal droplet in front.

8. The method for metal droplet agglomeration according to claim 7, characterized in that, The preset conditions include: the detection sensor detects that the size of the agglomerated metal droplets meets the preset droplet size requirement, or the detection sensor detects the size of multiple metal droplets, and the controller (3) calculates that the sum of the volumes of the multiple metal droplets meets the preset droplet volume requirement.

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